Article

Menstrual cycle-related changes in plasma oxytocin are relevant to normal sexual function in health women

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Abstract

Circulating levels of the neuro-hypophysial nonapeptide oxytocin increase during sexual arousal and orgasm in both men and women. A few studies have evaluated the effect of the menstrual cycle on plasma oxytocin in normally cycling, sexually active, healthy fertile women using or not using contraceptive pills. In 20 ovulating women and 10 women taking an oral contraceptive (group 1 and group 2, respectively), sexual function, hormonal profile, and plasma oxytocin (OT) were evaluated throughout the menstrual cycle. In group 1, plasma OT was significantly lower during the luteal phase in comparison with both the follicular and ovulatory phases. Plasma oxytocin was significantly correlated with the lubrication domain of the Female Sexual Function Index (FSFI) during the luteal phase and showed a trend towards statistical significance during the follicular phase. In group 2, plasma OT did not show any significant fluctuation throughout the menstrual cycle, even though a significant correlation was evident with both the arousal and the lubrication domain of the FSFI during the assumption of the contraceptive pill. These findings suggest that plasma OT fluctuates throughout the menstrual cycle in normally cycling healthy fertile women with adequate sexual activity but not taking any oral contraceptive pill. Moreover, plasma OT levels significantly relates to the genital lubrication in both women taking and not taking oral contraceptive pill apparently confirming its role in peripheral activation of sexual function.

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... They were asked to avoid alcohol consumption 24 h prior to their session, and to avoid smoking and caffeine 2 h before. Female participants were excluded from taking part because (i) they would be required to take a pregnancy test prior to taking part, presenting additional ethical concerns; and (ii) there is some evidence that OT concentrations fluctuate during the menstrual cycle [59,60] and that this is affected by royalsocietypublishing.org/journal/rstb Phil. Trans. ...
... R. Soc. B 377: 20210056 contraceptives [59]. Participants from the School of Psychology were awarded course credits in compensation for taking part; participants from other schools were paid for taking part. ...
Article
Identifying emotions correctly is essential for successful social interaction. There is therefore a keen interest in designing therapeutic interventions to improve emotion recognition in individuals who struggle with social interaction. The neuropeptide oxytocin has been proposed as a potential physiological intervention due to its important role in emotion recognition and other aspects of social cognition. However, there are a number of caveats to consider with the current form of intranasal oxytocin commonly used in the literature. Psychological interventions, on the other hand, do not carry the same caveats, and there is, therefore, a need to understand how intranasal oxytocin administration compares to psychological interventions designed to target the same psychological phenomena; and whether a combined intervention approach may provide additive benefits. Here we present a pilot, proof-of-concept study in healthy volunteers comparing the effect of intranasal oxytocin against a validated emotion training programme, finding that the psychological intervention, and not intranasal oxytocin, improved emotion recognition specifically for angry expressions. We discuss the theoretical implications of the research for future clinical trials. This article is part of the theme issue ‘Interplays between oxytocin and other neuromodulators in shaping complex social behaviours’.
... Figure 1 is a concatenation of serial levels of OT, estrogen, Mg 2+ , Na + , estrogen, cholesterol, and IL-6 over the menstrual cycle that are extracted from published sources. 11,[65][66][67][68] Local or circulating OT levels OT levels vary over the menstrual cycle and are lowest at days −2 to +3 of the cycle 67 -the same time period during which MRM attacks occur. What precipitates this drop? ...
... During the menstrual cycle, estrogen drops approximately at the same time as OT drops. 65,67 Estrogen can stimulate both OT synthesis 69 ...
Article
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Objective: To highlight the emerging understanding of oxytocin (OT) and oxytocin receptors (OTRs) in modulating menstrual-related migraine (MRM). Background: MRM is highly debilitating and less responsive to therapy, and attacks are of longer duration than nonmenstrually related migraine. A clear understanding of the mechanisms underlying MRM is lacking. Methods: We present a narrative literature review on the developing understanding of the role of OT and the OTR in MRM. Literature on MRM on PubMed/MEDLINE database including clinical trials and basic science publications was reviewed using specific keywords. Results: OT is a cyclically released hypothalamic hormone/neurotransmitter that binds to the OTR resulting in inhibition of trigeminal neuronal excitability that can promote migraine pain including that of MRM. Estrogen regulates OT release as well as expression of the OTR. Coincident with menstruation, levels of both estrogen and OT decrease. Additionally, other serum biochemical factors, including magnesium and cholesterol, which positively modulate the affinity of OT for OTRs, both decrease during menstruation. Thus, during menstruation, multiple menstrually associated factors may lead to decreased circulating OT levels, decreased OT affinity for OTR, and decreased expression of the trigeminal OTR. Consistent with the view of migraine as a threshold disorder, these events may collectively result in decreased inhibition promoting lower thresholds for activation of meningeal trigeminal nociceptors and increasing the likelihood of an MRM attack. Conclusion: Trigeminal OTR may thus be a novel target for the development of MRM therapeutics.
... Moreover, according to Salonia et al, 41 in normal cycling women, oxytocin varied significantly during the menstrual cycle with significant lower levels during luteal phase and correlated with FSFI lubrification 42 . They found a significant correlation between the oxytocin levels and both the FSFI arousal 42 ...
... Despite the relevance of the oxytocin in the social cognition and emotions, a limited number of studies investigated the role played by the oxytocin levels in human sexual behavior. The present systematic review took into account only studies that assessed the oxytocin levels without considering the randomized [28][29][30][31][32][33][34][35][36][37][38]40,41 In this way, given the subjective reports, it was not possible to quantify the intensity or the exact moment in which sexual arousal and orgasm occurred. Previous studies used psychophysiological techniques to record the variation of the penile circumference and vasocongestion of the vaginal wall during tasks like visual sexual stimulation. ...
Article
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Introduction Despite its role in social cognition and affiliative behavior, less is known about the role played by oxytocin in human sexual behavior. Aim In the present systematic review, we aimed to find the levels of oxytocin related to human sexual arousal and orgasm. Methods We conducted the study according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. We performed a systematic search in the principal databases for studies that reported collection of salivary or plasmatic samples, with dosage of oxytocin in relation to sexual activity during induction of sexual arousal and orgasm. Results 414 articles were obtained. After duplicates removal and the application of pre exclusion criteria, 16 articles were considered eligible and 13 articles were included with a Cohen's k of 0.827. Most of the studies used sexual self-stimulation and collected plasmatic or salivary samples to measure oxytocin. The sexual arousal and orgasm were assessed based on subjective reports. Main Outcome Measure The primary outcomes were the oxytocin levels collected during the induction of sexual arousal and orgasm. Conclusions Several studies collected only subjective reports about the sexual arousal and the orgasm. Most of the studies found higher levels of oxytocin during the orgasm or ejaculation. Given the sexual arousal evoked by self-stimulation in which sexual fantasies play an important role, it should be possible to postulate for a role of the oxytocin in sexual desire. In particular, we hypothesize a complex role of the oxytocin in the modulation of sexual fantasies and thoughts that are relevant in the sexual desire and help to trigger genital and sexual arousal.
... Additional puffs were administered when the administered amount fell below 600 mg. Dosage and administration procedure were based on the current literature about kinetics in men and guidelines for standardised nasal administration 62,67 . ...
Preprint
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Expectations about the quality of a medical treatment influence how much an inert treatment helps to improve patient well-being. Similarly, expectations about the quality of products influence how identical goods and services are evaluated differently after their consumption. One driver for such "placebo effects" in medical treatments is social cognition in the form of trust, which may be influenced by the hormone oxytocin. An open question is whether trust and oxytocin play similar roles in marketing placebo effects. To answer this question, we combined oxytocin administration (24 IU) and trust questionnaires in a pre-registered double-blind randomized between-subjects study design (N food tasting task = 223; N cognitive performance task = 202). We could not find evidence that oxytocin and trust play a role in placebo effects of marketing actions. Together with other recent null findings from oxytocin administration studies, these findings question the role trust might play in different types of placebo effects.
... We finally selected a relatively moderate sample size, which has enough power, but the sample size still needs to be increased as much as possible to verify the universality and reliability of the results. In addition, not only estradiol and progesterone, but also prolactin and oxytocin, etc., can vary with the menstrual cycle, and both are also increased in the late follicular phase [48]. Whether these two hormones affect the participants' performance of approach-avoidance needs to be further investigated in future studies. ...
Article
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The menstrual cycle affects women’s emotional states, with estrogen and progesterone having predominant roles. However, it remains unclear whether the phases of the menstrual cycle also affect women’s motivational behaviors. In this study, the main aim was to investigate how the menstrual cycle influences approach–avoidance behavior under conditions of conscious versus unconscious processing of emotions. Briefly, after recruitment by advertisement and screening with a menstrual cycle survey questionnaire, 27 naturally cycling, healthy women participated in an improved “manikin task” and were presented both positive and negative emotional stimuli during early follicular, late follicular, and mid-luteal phases. Estrogen and progesterone levels were measured. Women in the late follicular phase exhibited the shortest response times for approaching positive stimuli, while women in the mid-luteal phase exhibited the shortest response times for avoiding negative stimuli. Estrogen and progesterone levels significantly correlated with the speed of the approach–avoidance responses observed for the women, indicating the important role that sex hormones have in mediating emotionally motivated behavior. Overall, these findings suggest that the menstrual cycle has strong and specific influences on women’s approach–avoidance behaviors that are in part mediated by estrogen and progesterone. By identifying characteristics of these behaviors in the late follicular and mid-luteal phases, greater insight can be provided to women regarding the physiological influences of the menstrual cycle on their personal growth and security.
... Additionally, the female samples with AUD patients and healthy controls were balanced in terms of postmenopausal status because the activity of the OXT system is influenced by the menstrual cycle status [62]. Nevertheless, we had an insufficient sample size of premenopausal women to accurately account for fluctuations in the hormonal profile that occur during the menstrual cycle and are known to influence behavior [63]. The OXT system plays an important socio-sexual and socio-emotional role, and we did not account for and investigate bonding behavior, anxiety regulation, and adverse childhood experiences [6,44]. ...
Article
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Alcohol use disorder (AUD) is a major global mental health challenge. Knowledge concerning mechanisms underlying AUD and predictive biomarkers of AUD progression and relapse are insufficient. Recently, addiction research is focusing attention on the oxytocin system. However, to our knowledge, blood concentrations of the oxytocin receptor (OXTR) have not yet been studied in AUD. Here, in sex-separated analyses, OXTR serum concentrations were compared between early-abstinent in-patients with AUD (113 men, 87 women) and age-matched healthy controls (133 men, 107 women). The OXTR concentrations were correlated with sex hormone and oxytocin concentrations and alcohol-related hospital readmissions during a 24-month follow-up. In male patients with AUD, higher OXTR concentrations were found in those with an alcohol-related readmission than in those without (143%; p = 0.004), and they correlated with more prospective readmissions (ρ = 0.249; p = 0.008) and fewer days to the first readmission (ρ = −0.268; p = 0.004). In men and women, OXTR concentrations did not significantly differ between patients with AUD and controls. We found lower OXTR concentrations in smokers versus non-smokers in female patients (61%; p = 0.001) and controls (51%; p = 0.003). In controls, OXTR concentrations correlated with dihydrotestosterone (men, ρ = 0.189; p = 0.030) and testosterone concentrations (women, ρ = 0.281; p = 0.003). This clinical study provides novel insight into the role of serum OXTR levels in AUD. Future studies are encouraged to add to the available knowledge and investigate clinical implications of OXTR blood concentrations.
... The current study was conducted as part of a larger project focused on the effects of oxytocin on social cognition. The luteal phase was of interest in this prior study due to low plasma oxytocin levels during this phase (Altemus et al., 2001;Evans et al., 2003;Mitchell et al., 1981;Salonia et al., 2005;Stock et al., 1991). Important to the current study, estrogen regulates oxytocin, and oxytocin plays a role in estrogendependent behavioral responses (McCarthy, 1995). ...
Article
Empathy is a component of social cognition that allows us to understand, perceive, experience, and respond to the emotional state of others. In this study, we seek to build on previous research that suggests that sex and hormone levels may impact white matter microstructure. These white matter microstructural differences may influence social cognition. We examine the fractional anisotropy (FA) of white matter pathways associated with the complex human process of empathy in healthy young adult females during the self-reported luteal phase of their menstrual cycle. We used tract-based spatial statistics to perform statistical comparisons of FA and conducted multiple linear regression analysis to examine the strength of association between white matter FA and scores on the Empathy Quotient (EQ), a self-report questionnaire in which individuals report how much they agree or disagree with 60 statements pertaining to their empathic tendencies. Results identified a significant negative relationship between EQ scores and FA within five clusters of white matter: in the left forceps minor/body of the corpus callosum, left corticospinal tract, intraparietal sulcus/primary somatosensory cortex, superior longitudinal fasciculus, and right inferior fronto-occipital fasciculus/forceps minor. These consistent findings across clusters suggest that lower self-reported empathy is related to higher FA across healthy young females in specific white matter regions during the menstrual luteal phase. Future research should seek to examine if self-reported empathy varies across the menstrual cycle, using blood samples to confirm cycle phase and hormone levels.
... To the best of our knowledge, the effects of HC on the oxytocinergic system have not yet been investigated in animal models. In women, oxytocin levels fluctuate across the menstrual cycle, being lower during the luteal phase, while no such fluctuations were observed in women taking HC (Salonia et al., 2005), although other studies reported an increase in plasma oxytocin in women under HC treatment (Silber et al., 1987;Stock et al., 1994). Moreover, HC alter oxytocin-mediated reward sensitivity to social and sexual stimuli in women (Scheele et al., 2016), suggesting that they may also influence social and sexual behavior through the oxytocinergic system. ...
Article
Steroid hormones influence different aspects of brain function, including development, neurogenesis, neuronal excitability, and plasticity, thus affecting emotional states, cognition, sociality, and reward. In women, their levels fluctuate across the lifespan and through the reproductive stages but are also altered by exogenous administration of hormonal contraceptives (HC). HC are widely used by women throughout their fertile life both for contraceptive and therapeutic benefits. However, awareness of their effects on brain function and behavior is still poorly appreciated, despite the emerging evidence of their action at the level of the central nervous system. Here, we summarize results obtained in preclinical studies, mostly conducted in intact female rodents, aimed at investigating the neurobiological effects of HC. HC can alter neuroactive hormones, neurotransmitters, neuropeptides, as well as emotional states, cognition, social and sexual behaviors. Animal studies provide insights into the neurobiological effects of HC with the aim to improve women’s health and well-being.
... Diferentes tipos de evidencias pueden apoyar esta hipótesis: primero, en humanos se ha demostrado que la exposición a hormonas sexuales induce cambios periféricos epigenéticos en el gen del OXTR, en la expresión de receptores de oxitocina y en los niveles de oxitocina (Berio, Divari, Starvaggi Cucuzza, Biolatti, & Cannizzo, 2017;Kimmel et al., 2016;Salonia et al., 2005); segundo, hay reportes de la interacción entre los genotipos para síntesis de receptores de oxitocina y de hormonas sexuales sobre las conductas sexuales y sociales en humanos (Armeni et al., 2017); tercero, en mamíferos se ha demostrado el efecto de las hormonas sexuales sobre la expresión límbica de oxitocina y receptores de oxitocina (Keebaugh & Young, 2011); y cuarto, existen consistentes referencias a que las diferencias dependientes del sexo entre los genotipos del OXTR se agudizan en la adolescencia, incluyendo diferencias en la actividad de estructuras límbicas como la amígdala y el estriado (Andreou et al., 2018;Schneider-Hassloff et al., 2016c;Shao et al., 2018;Waller et al., 2016). Determinar si las diferencias entre los sexos a través de la adolescencia en el funcionamiento emocional y neural dependen de la influencia de las hormonas sexuales y cuáles son los mecanismos responsables de esta moderación requerirá de investigaciones traslacionales que incluyan estudios experimentales moleculares, genéticos, epigenéticos, fisiológicos, del neurodesarrollo y conductuales en modelos con tejidos y animales no-humanos y estudios correlacionales y epidemiológicos en humanos que incluyan mediciones epigenéticas, genéticas y ambientales. ...
Thesis
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Millones de colombianos han sido expuestos a experiencias adversas durante la niñez (EAN), las cuales suelen llevar a alteraciones en el funcionamiento emocional y neurofisiológico. Sin embargo, polimorfismos como el rs53576 del receptor de oxitocina (OXTR) parecen modular estos efectos. Actualmente, no es claro cómo la interacción entre la exposición a EAN y los polimorfismos del OXTR influyen sobre el funcionamiento cerebral y emocional en adolescentes. Por lo tanto, en este proyecto se indagó sobre qué interacciones existen entre el grado de EAN, el polimorfismo rs53576 del OXTR y el funcionamiento emocional y neurofisiológico en adolescentes de un municipio colombiano. Se entrevistaron 261 adolescentes del municipio de Soacha, con edades entre los 12 y 18 años. Las EAN se evaluaron a través de la escala de eventos adversos en la niñez y el genotipo OXTR se obtuvo a partir de genotipificación del SNP rs53576. Las medidas de funcionamiento emocional se obtuvieron a través de: tarea de reconocimiento de rostros emocionales, prueba de estrés social de Trier (TSST), tarea de empatía al dolor y el reporte parental de problemas de conducta (CBCL). El funcionamiento cerebral fue analizado a través de un paradigma de potenciales relacionados a eventos (PRE) para el procesamiento de imágenes afectivas. Los principales resultados fueron: alta frecuencia de EAN, el conflicto armado influyó significativamente en el desarrollo emocional, la frecuencia genotípica del OXTR fue similar a la de otras poblaciones de América Latina y hubo un efecto conjunto de las EAN y el genotipo OXTR sobre todas las medidas de funcionamiento emocional y los componentes PRE, el cual dependió del sexo y edad. Se discuten estos resultados desde: la sensibilidad diferencial conferida por los polimorfismos del OXTR hacia las señales sociales amenazantes y protectoras; la interacción entre la señalización oxitocinérgica y las hormonas sexuales durante la adolescencia; la plasticidad en el desarrollo cerebral y emocional; las limitaciones metodologías del estudio; y las posibles implicaciones para las intervenciones psicológicas y para las investigación en las ciencias del comportamiento, la salud y las neurociencias.
... Although some studies have reported that OT concentrations are increased in both sexes during sexual orgasm (Blaicher et al., 1999) or in response to social touch , and may act synergistically with estrogen (Amico et al., 1981;Young et al., 1998;Patisaul et al., 2003;Salonia et al., 2005), there is still no compelling evidence that OT actually increases sexual desire in women and potentially the increased release following orgasm or in response to touch may function primarily to strengthen bonds between partners. Indeed, the study showing that OT facilitated social sharing behaviors in pair-bonded marmosets found no evidence that it increased female sexual behavior (Smith et al., 2010). ...
Article
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In humans, the neuropeptide oxytocin promotes both attraction toward and bonds with romantic partners, although no studies have investigated whether this extends to the perceived attractiveness of flirtatious language. In a within-subject, randomized double-blind placebo-controlled behavior and functional magnetic resonance imaging (fMRI) paradigm ( https://clinicaltrials.gov/show/NCT03144115 ), 75 women rated the attractiveness of either a male face alone or paired with a verbal compliment which varied in terms of topic (women or landscapes) and figurativeness (novel or conventional metaphors or literal expressions). Subjects were tested in fertile and luteal phases of their cycle and on both occasions received either 24 IU intranasal oxytocin or placebo. Results showed that, whereas under placebo women in the fertile phase rated the facial attractiveness of men producing novel metaphorical compliments higher than in their luteal phase, following oxytocin treatment they did not. Correspondingly, under oxytocin the faces of individuals producing novel metaphorical compliments evoked greater responses in brain regions involved in processing language (middle frontal gyrus) and cognitive and emotional conflict (posterior middle cingulate and dorsal anterior cingulate) but reduced functional connectivity between the dorsal anterior cingulate and right orbitofrontal and medial frontal gyri. Thus, sex hormones and oxytocin may have opposite effects in regulating mate selection in women during their fertile phase. Novel metaphorical compliments convey a greater sexual than bonding intention and thus while sex hormones at mid-cycle may promote attraction to individuals communicating sexual rather than bonding intent, oxytocin may bias attraction away from such individuals through increasing cognitive and emotional conflict responses toward them.
... Hormones are the first chemical messengers to reach the target cell where they bind to receptors found in or on the cell. This stimulates second messengers, which induce cellular responses in the following manner (Waugh and Grant 2006;Bullock and Grossberg 1991;Bullock et al. , 2001Burkitt et al. 1996;Gardner and Shoback 2011;Guyton 1986;Guyton andHall 2006, 2016;Nakhla et al. 1989;Gancz and Lilach 2013;Gribble and Reimann 2017;Salonia et al. 2005;Feillet 2010;Lin et al. 2015;Ghorbani and Naderi-Meshkin 2016;Parikh et al. 2017;Odle et al. 2018;Salvatore 2018). ...
Chapter
Endocrine system has vital roles and is influenced by complex factors and signaling to achieve accurate rhythm and patterns of hormone secretion and effects. The endocrine system effect is slow to start but it can take long-term actions. Endocrine system is an integrated communicative tool for the human body, performing various functions through its hormones as chemical messengers. The pituitary gland is the master regulator of the endocrine system, which coordinates and controls the function of other glands in the body through secretion and signals of stimulating/inhibiting hormones. The signal transduction mechanism of the hormones is mediated by binding with cell surface receptors and stimulating multifactorial downstream targets including second messengers involving cyclic adenine monophosphate (cAMP), calcium ions, and 3-cyclic guanosine monophosphate (cGMP), to induce cellular response and physiological functions. Hormones govern receptor regulation and number, regulate ion transport and membrane permeability, regulate substances and minerals in the blood and cells. Due to their highly restricted functions, the elasticity and plasticity of human endocrine system suggest a powerful history of adaptation to changing environments. The main axis such as hypothalamus-pituitary-adrenal under stress, hypothalamus-pituitary-gonadal and -pineal axis play key roles over important periods. The circadian clock acts carefully to regulate each level of the pituitary-hypothalamus axis ensuring proper compatibility of physiological functions during daylight, either under normal or abnormal conditions. Additionally, the endocrine system plays a key role in maintenance, regeneration, and remodeling the tissues by governing stem/progenitor cells, sexual and mental maturation. It is also overcoming some limitation of stem cell’s treatment. This chapter details the hormone secretion mediated cellular events and wide spectrum of its functions.KeywordsEndocrine systemCell signalingMessengersHormoneStem cellPermeabilityCircadian rhythmGrowthReceptorStressHypothalamusPituitary
... • Increasing the activity of the enzyme aromatase: Rapid actions of estradiol are mediated through changes in aromatase activity, which accurately regulates the temporal and spatial availability of estrogene (Rudolph et al. 2016b). • Local hormones, such as oxytocin which is secreted from the luteal cells and reduces the secretion of progesterone (Salonia et al. 2005). Also, autocrine signals like prostaglandins released from uterus or ovary during the post-ovulatory phase (such as prostaglandin E2 and prostaglandin F2-alpha. ...
Chapter
Reproduction is an important biological process of species evolution, it is leading to new offspring from parents. The pituitary gland (the master gland) in the endocrine system in coordination with the hypothalamus plays a vital role in the reproductive system, differentiation, and different physiological functions in the entire stages of life and its circadian rhythm in both males and females. The chapter deals with the prominent role played by the brain, endocrine system, and gonads axis through complex communicating signals. The male gonads are the location of testicles, interstitial tissue (Leydig cells), and peritubular myoid cells. Sertoli cells act as “nurse and stem” cells, spermatogenesis, spermiogenesis were explained. Gonad’s steroid hormones (Androgens) characteristics are specified in male reproductive activity, biological actions along with the regulator hormones (follicle-stimulating hormone, luteinizing hormone, and hypothalamic–pituitary–Leydig cell axis. Ovaries are female reproductive glands. The chapter describes the tissue zones of ovaries, puberty, and two main functions (exocrine and endocrine) controlled and coordinated by the hypothalamus and the pituitary. Female sex hormones in pre-puberty (Estrogen) and post-puberty (estradiol, estrone, progesterone, and inhibin), and sources (ovarian follicle and corpus luteum) were discussed in detail. Structure of steroid hormones discussed with the role of the endometrium, regulation of ovarian functions, and puberty by endocrine and immune system. The different phases of the ovarian cycle are explained to regulate gonadotropins, follicular growth, steroid synthesis, non-functional corpus albicans (infertile ovum), and regulation of the ovarian cycle (pre-ovulatory phase, ovulation phase, and post-ovulatory phase). The involvement of estradiol metabolites, enzyme aromatase, the hormone oxytocin, matrix metalloprotease, cytokines, and vasoconstriction in corpus luteum formation is related along with maintenance and regression. Synthesis of ovarian hormones (β-estradiol, estrone, and estriol) after puberty discussed with important functions of progesterone, regulatory roles of inhibin, activin, and follistatin in the physiology of testis and ovary. Dehydroepiandrosterone (DHEA) involvement was discussed for menopause in elderly women and andropause in men. The chapter declares that the classic theory of cessation of oocytes production after birth was canceled. Both human neonatal and adult ovarian germline stem-cell precursors (ovarian surface cells) have the capability for oogenic/differentiating and producing functional oocytes, so it renews the oocyte pool (neo-oogenesis) and ensures renewal during the prime reproductive period, with follicular cooperation under the regulation of the endocrine, immune systems, and cellular support. After the prime reproductive period, aging starts, and menopause occurs because of the immunoregulatory changes that cause cessation and terminate neo-oogenesis and follicular renewal in vivo despite the existence of germline stem cell precursors. The rest of the oocytes in the primordial follicles retain ovarian function but advancing age (aging oocytes) correlates positively with the occurrence of fetal chromosomal abnormality. This chapter discusses the topics related to regulation of male and female reproductive functions.KeywordsFollicle-stimulating hormoneLuteinizing hormoneOvaryTestisReproductive hormoneStem cell
... In addition, it should be noted that estradiol and progesterone are not the only hormones that fluctuate during the menstrual cycle. Prolactin and oxytocin levels also increase during the late FP [74]. ...
Article
Numerous studies have shown that perception of emotion and emotional memory vary across the menstrual cycle. However, most of these studies used stimuli that contained not only emotional but also social elements. Importantly, the social cognitive abilities of individuals are as crucial as emotional abilities for danger avoidance and recruitment of allies. Therefore, the issue that natural hormonal fluctuations may affect emotion processing should be revisited. To investigate whether the effects of the menstrual cycle are emotion-specific or can also be attributed to social information processing, the present study examined social attention across the menstrual cycle in three tasks—visual search, memory, and memory-guided orienting—with a combination of behavioral and eye-tracking measures. We used images of people standing upright with neutral emotion as social distractors and everyday objects with physical properties matched as non-social distractors. Thirty-six healthy women without hormone use and with stable menstrual cycles of 26 to 30 days participated in the three tasks in the late follicular phase (FP) and mid-luteal phase (LP), respectively. During visual search, participants were asked to search for targets accompanied by social or non-social distractors in complex scenes. Social attentional bias, as evidenced by longer search times and shorter gaze behaviors for targets with social distractors, was found in the FP but not in the LP. In the following memory task, memory accuracy for targets was higher in the FP than in the LP, and the memory for targets with social distractors was more precise in both phases. Finally, in the orienting task, targets in social scenes were detected more slowly than in non-social scenes in LP. Taken together, these findings point to the interplay between social attention, memory, and memory-oriented attention and reveal the distinct processing pathways for social information in the FP and LP. The underlying mechanisms from an evolutionary perspective and from behavioral and neural basis were discussed.
... We chose to only examine male patients because they constitute the vast majority of the forensic mental hospital population. Also oxytocin fluctuates throughout the menstrual cycle and the use of oral contraceptives influences these fluctuations (Salonia et al., 2005). Different hormones interact and cortisol and testosterone might affect oxytocin levels. ...
Article
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Oxytocin and vasopressin are neuropeptides implicated as modulators of human aggressive behavior. In animal models, administration of oxytocin generally attenuates aggressive behavior, but in humans the effects of oxytocin appear to be more nuanced. Vasopressin seems to have an opposing influence on aggression in animal studies, but much less research has been done in humans. We performed a cross-sectional study in which we measured oxytocin and vasopressin levels in forensic psychiatric male patients with a personality disorder (N = 38) and healthy male controls (N = 108). Elevated salivary oxytocin (B = −0.10, P = 0.02) and reduced urinary vasopressin (B = 0,19, P < 0.01) levels were found in patients compared to controls. Within the patient group urinary oxytocin levels were positively associated with psychopathy scores as measured with the PCL-R (B = 0.02, P = 0.02). These findings suggest that baseline levels in forensic psychiatric patients diagnosed with a primary personality disorder might be counterintuitive, as oxytocin levels are higher than expected and vasopressin levels are lower than those of healthy controls. More generally, the results imply a complex role of these neuropeptides on human behavior, in line with the social salience theory.
... They were asked to avoid alcohol consumption 24 hours prior to their session, and to avoid smoking and caffeine consumption in the preceding 2 hours. Female participants were not recruited due to evidence that OT concentrations interact with the menstrual cycle ( Salonia et al., 2005 ). Participants who were psychology students were awarded course credits; participants from other schools received £20. ...
Article
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The neuropeptide oxytocin (OT) has been shown to influence social cognition, including better recognition of emotion in faces. One potential way in which OT improves emotion recognition is by increasing the correspondence between a perceiver's own facial activity and observed facial expressions. Here we investigate whether increased facial synchrony while viewing facial expressions increases emotion recognition, and whether this effect is moderated by OT. Change in visual attention as captured by eye-gaze is another way in which OT might improve emotion recognition. We also examine visual attention to observed expressions, and whether this is influenced by OT. One hundred and four male undergraduates took part in a double-blind, randomized, between-subjects study in which they self-administered either a placebo (PL) or 24 IU of OT before viewing dynamic facial expressions of emotion, during which their facial activity and eye-gaze were measured, before answering questions on emotion recognition and affiliation. It was hypothesized that participants in the OT condition would exhibit more facial synchrony than would those in the PL condition, and that OT would influence time spent looking at the eye region of target faces. Consistent with previous research, participants in the OT condition were marginally but significantly better at emotion recognition than those in the PL condition. However, participants in the OT condition displayed less facial synchrony for fearful expressions, and there was no effect of OT on measures of eye-gaze. These results suggest that OT does not improve emotion recognition through increased facial synchrony or changing visual attention.
... 26 Oxytocin also interacts with dopamine and has been shown to promote bonding, orgasm, and sexual desire. 27 Importantly, estradiol stimulates the release of α-MSH 28 and oxytocin, 29 which has clinical relevance when treating menopausal women with HSDD, as low levels of estradiol will likely decrease oxytocin and α-MSH, and potentially contribute to symptoms of decreased desire. ...
Article
Nearly half of women in the United States report problems with sexual function. Many health care providers do not ask about sexual concerns during routine clinical encounters because of personal discomfort, lack of familiarity with treatment, or the belief that they lack adequate time to address this complex issue. This may be especially true for hypoactive sexual desire disorder (HSDD), the most commonly identified sexual problem among women. HSDD is characterized by a deficiency of sexual thoughts, feelings, or receptiveness to sexual stimulation that has been present for at least 6 months, causes personal distress, and is not due to another medical condition. This is an up‐to‐date overview of HSDD for clinicians, discussing its physiology, assessment, diagnosis, and treatment strategies. Although a definitive physiology of HSDD is still unknown, multiple hormones and neurotransmitters likely participate in a dual‐control model to balance excitation and inhibition of sexual desire. For assessment and diagnosis, validated screening tools are discussed, and the importance of a biopsychosocial assessment is emphasized, with guidance on how this can be implemented in clinical encounters. The 2 recently approved medications for HSDD, flibanserin and bremelanotide, are reviewed as well as off‐label treatments. Overall, HSDD represents a common yet likely underrecognized disorder that midwives and other health care providers who care for women across the life span are in a unique position to address.
... Only men were included in the current study to avoid any complexity due to fluctuations in plasma oxytocin and sex hormones across the menstrual cycle of women [60]. Indeed, several studies have reported potential sex differences in OXT administration. ...
Article
Full-text available
Oxytocin (OXT) is known to affect various social processes, including social comparison and intergroup competition. In this study we examined whether social comparisons in intergroup situations can be modulated by OXT and, if so, how this modulation manifests. Using a double-blind placebo-controlled design, we randomly assigned male participants to either OXT or placebo treatment and then asked them to play a card game with either an in-group or an out-group member. The OXT-treated participants showed a greater social comparison effect in the games with an out-group member than in the games with an in-group member. Specifically, the participants in the OXT treatment condition showed a greater acceptance rate for relative gain (downward comparison) and a lesser acceptance rate for relative loss (upward comparison) while playing with an out-group member rather than an in-group member. By contrast, no such effect was observed among the placebo-treated participants. These findings demonstrate that OXT facilitates intergroup social comparisons with an out-group versus an in-group member.
... Previous scientific research on the role of OT in human reproduction is mainly concentrated on the periphery. Many studies have proved a prominent increase in plasma OT levels during sexual arousal and immediately the following orgasm in both men and women [43,44]. However, with the development of neuroimaging techniques, like functional magnetic resonance imaging studies (fMRI) and positron emission tomography (PET), the focus mostly transfers into OT's central effects. ...
Chapter
Full-text available
Oxytocin, an important neuropeptide, exerts a wide influence on the central nervous system and the peripheral tissues. In the central nervous system, the oxytocin gene expression is mainly shown to be present in neurons in the hypothalamic paraventricular and supraoptic nuclei. Oxytocin gene also transcribes in the peripheral tissues such as uterus, placenta, and amnion. Oxytocin receptors can be founded in many tissues in humans, like the uterine, ovary, testis, kidney, and so on. And just in the same tissue, due to the variation of physiology factors, the amount of oxytocin changes a lot. Oxytocin secretion is closely linked with pregnancy advancing. During labor, the contractions of uterine smooth muscles and oxytocin secretion are inseparable. Moreover, oxytocin is also responsible for stimulating milk ejection after parturition. Oxytocin is associated with many diseases. Poor regulation of oxytocin may cause postpartum depression and infantile autism. In terms of physiology, fatal heart failure and gestational hypertension are concerned with oxytocin level. In this chapter, we will discuss the oxytocin in pregnancy as well as its clinical applications.
... This lack of cycle-related may be explained by the suppression of endogenous hormones by their synthetic counterparts. 3,33 Furthermore, our study suggests that higher severity of premenstrual symptoms is associated with a decrease in physical and task attraction. Although this is not explicitly investigated in other studies, the authors showed that physical discomfort relating to premenstrual symptoms is a result of increased estradiol levels. ...
Article
Purpose: to examine the association between menstrual cycle phases and other factors (depression, anxiety and stress) with social, physical, and task attraction. Methods: This cross-sectional study enrolled 662 female university students (December 2019-January 2020). Results: Higher stress was associated with higher social and task attraction. Higher stress and depression were associated with higher physical attraction, whereas higher anxiety was associated with lower physical attraction. None of the cycle’s phases was associated with attraction. Practical implications: This study results showed a lot of contradictory information to what is present in the literature, in addition to new associations that are not tackled enough in the literature. Therefore, there is a crucial need for new firm studies that explore the relation between women’s hormonal levels and attraction levels.
... We did not find any associations between menstrual cycle phase and plasma OT levels in our sample. Previous research has revealed plasma OT fluctuations over the course of the menstrual cycle (Salonia et al., 2005). It should be noted, however, that a more recent study found no association between OT levels and contraception use or menstrual cycle (Weisman et al., 2013). ...
Article
The role of oxytocin (OT) in close relationships is complex, as both positive and negative associations have been found between OT and relationship processes. Also, with most research focusing on the effects of exogenous OT administration on communication and couple behaviors, our knowledge about the association between endogenous OT and couple dynamics remains limited. This study is the first to assess the link between peripheral OT levels and observed communication behaviors during sexual and nonsexual conflict discussions in romantic relationships. A sample of 126 young, heterosexual couples (Mean age = 23.3, SD = 2.4; average relationship duration = 1.9 years, SD = 0.9) participated in videotaped sexual and nonsexual couple conflict discussions of 7 minutes each. Communication behaviors were coded using an adaptation of the Specific Affect Coding System (SPAFF) and the System for Coding Interactions and Family Functioning (SCIFF). Blood samples were collected prior to the couple discussions, during a separate lab visit, and OT plasma levels were determined using enzyme-linked immunosorbent assays (ELISA). Plasma OT levels were positively associated with validating behaviors during sexual discussions in both women (r = +.24, p =.008) and men (r = +.18, p =.052). No significant associations were found between OT levels and validating behaviors during nonsexual discussions and between OT and affectionate and negative behaviors during either sexual or nonsexual discussions. Analyses revealed significant associations between OT levels and one’s own validating behaviors during sexual discussions (b = 47.82, t(201.16) = 3.81, p <.001) and one’s partner’s (b = 32.12, t(216.35) = 2.62, p =.009). The results highlight the biobehavioral aspects of couples’ sexual communication and may contribute to a better understanding of the processes involved in individual and relational well-being. This study is the first to report an association between peripheral OT levels and validating behaviors during sexual communication, indicating neurophysiological involvement in dyadic sexual communication patterns.
... One participant did not complete one of the four visits and for this reason was excluded from all analyses. We decided to focus our study on men because the levels of oxytocin have been shown to fluctuate across the menstrual cycle in women, which would introduce an additional level of unwanted variability in our sample 70 . We screened participants for psychiatric conditions using the Symptom Checklist-90-Revised 71 and the Beck Depression Inventory-II 72 questionnaires. ...
Article
Full-text available
Oxytocin has recently received remarkable attention for its role as a modulator of human behaviour. Here, we aimed to expand our knowledge of the neural circuits engaged by oxytocin by investigating the effects of intranasal and intravenous oxytocin on the functional connectome at rest in 16 healthy men. Oxytocin modulates the functional connectome within discrete neural systems, but does not affect the global capacity for information transfer. These local effects encompass key hubs of the oxytocin system (e.g. amygdala) but also regions overlooked in previous hypothesis-driven research (i.e. the visual circuits, temporal lobe and cerebellum). Increases in levels of oxytocin in systemic circulation induce broad effects on the functional connectome, yet we provide indirect evidence supporting the involvement of nose-to-brain pathways in at least some of the observed changes after intranasal oxytocin. Together, our results suggest that oxytocin effects on human behaviour entail modulation of multiple levels of brain processing distributed across different systems.
... Third, the in uence of the menstrual cycle on the uctuations in sOT levels may have been overlooked in this pilot study. However, uctuations in the peripheral oxytocin levels over the course of the menstrual cycle are controversial [48][49][50]. In our study, the amounts of sOT before resting, touching the SP sheet, and touching the LP sheet were not signi cantly different (F [2, 23] = 1.490, p = 0.2463, one-way analysis of variance with Tukey's post hoc test). ...
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Objective The aim of this pilot study was to investigate whether or not tactile contact between a diaper-like nonwoven sheet with specific physical characteristics and the palm of the hand would increase the maternal level ofoxytocinwhich is one of the neuropeptides promoting formation of the mother-infant bond. Results Ten healthy non-breastfeeding Japanese mothers were enrolled in this pilot study. We prepared diaper-like nonwoven sheets with large or small projections. Physical indices related to softness and fluffiness were higher in the sheet with large projections than in the sheet with small projections. Salivary oxytocin levels in the motherswere increasedafter tactile contact with thesheet with large projections, but not after contact with the sheet with small projections. This pilot study suggests that maternal oxytocin levels are increased by tactile contact between a soft and fluffy diaper sheet and the palm.
... Exclusion criteria involved drug/alcohol abuse, nasal problems, use of medication (except contraception), psychiatric, cardiovascular/neurological disorders, hypertension, or pregnancy. As oxytocin levels vary during the menstruation cycle (Salonia et al., 2005) participants were preferably invited to the lab in the luteal phase. ...
Article
Full-text available
Oxytocin is known for its stress-reducing effects and has been associated with autonomic nervous system measures (ANS) involved in the stress response, such as heart rate variability (HRV). The current study examined the effects of intranasal oxytocin on HRV among women (oxytocin N=87, placebo N=86) during rest. Results show that oxytocin reduced RMSSD and low frequency (LF)-HRV, but only in women with positive childhood rearing experiences, and not in women with negative childhood experiences. These findings suggest that oxytocin plays a role in ANS regulation and that childhood rearing experiences may influence oxytocin effects on this stress regulating system.
... We recruited 17 adolescent and adult men with ASD and 24 TD male participants. In this study, we only included men because reported variations in OT levels in women are higher [52]. Participants with ASD (aged 16 to 39 years old) were recruited from the Department of Neuropsychiatry, University of Fukui Hospital, Japan, and the Department of Psychiatry and Neurobiology, Kanazawa University Hospital, Japan. ...
Article
Full-text available
Background: Previous research studies have assessed the relationship between attention to social information and peripheral (e.g., plasma and salivary) oxytocin (OT) levels in typically developing (TD) children and children with autism spectrum disorder (ASD). A relationship between them was observed in TD children, but not in children with ASD. However, this relationship remains unexamined in other age groups. To clarify whether this lack of association is maintained throughout development in individuals with ASD, we aimed to assess the relationship between salivary OT levels and attention to social information in adolescents and adults with and without ASD. Methods: We recruited male adolescents and adults with ASD (n = 17) and TD participants (n = 24). Using the all-in-one eye-tracking system Gazefinder, we measured the percentage fixation time allocated to social information. We also measured the salivary OT levels and Autism Spectrum Quotient (AQ) of participants. Subsequently, we confirmed group differences and conducted a correlation analysis to investigate the relationships between these three measures. Results: Salivary OT levels did not show any significant difference between the ASD and TD groups and were negatively correlated with the AQ in the whole-group analysis, but not in within-group analysis. Individuals with ASD had significantly lower percentage fixation times than did TD individuals for eye regions in human faces with/without mouth motion, for upright biological motion, and for people regions in the people and geometry movies. The percentage of fixation for geometric shapes in the people and geometry movies was significantly higher in the ASD than in the TD group. In the TD group, salivary OT levels were positively correlated with percentage fixation times for upright biological motion and people and negatively correlated with inverted biological motion and geometry. However, no significant correlations were found in the ASD group. Conclusions: Our exploratory results suggest that salivary OT levels in adolescents and adults with ASD are less indicative of attention to social stimuli than they are in TD adolescents and adults. It is suggested that their association is slightly weaker in adolescents and adults with ASD and that this attenuated relationship appears to be maintained throughout development.
... Considering the female endogenous oxytocin system, it is also necessary to control for the menstrual cycle [20]. Specifically, short-term (tonic) and long-term ( phasic) breastfeeding are factors that greatly influence a mother's endogenous oxytocin concentration and fluctuation. ...
Article
Full-text available
Breastfeeding behaviours can significantly change mothers' physiological and psychological states. The hormone oxytocin may mediate breastfeeding and mothers' emotion recognition. This study examined the effects of endogenous oxytocin fluctuation via breastfeeding on emotion recognition in 51 primiparous mothers. Saliva oxytocin was assessed before and after the manipulation (breastfeeding or holding an infant), and emotion recognition tasks were conducted. Among mothers who breastfed daily, mothers with more increased levels of oxytocin after breastfeeding showed more reduced negative recognition and enhanced positive recognition of adult facial expressions. These oxytocin functions accompanying breastfeeding may support continued nurturing behaviours and also affect the general social cognition of other adults beyond any specific effect on infants.
... The magnitude of this variation in oxytocin differs widely between women 44 , making it difficult to generalise a "baseline" oxytocin level in freely cycling women for comparison to OC -users. As noted by Salonia and co-workers 45 , women using OC do not show this variation. Few freely-cycling participants were ovulating based on self-reports and therefore unlikely to have significantly impacted the mean oxytocin levels in our non-OC user dataset. ...
Article
Full-text available
Oral contraception (OC) is used by approximately fifty-five million women in the USA alone and is listed as an essential medicine by the World Health Organisation. Altered mood is a common reason for OC cessation. Here we investigate the effects of OC on hormones that are linked to mood. We obtained blood samples from 185 young women (average age 21.2) in two cohorts and tested the effects of OC on plasma levels of oxytocin, adrenocorticotropic hormone (ACTH), estradiol, progesterone and testosterone. We related plasma hormone levels with self-reported measures of mood, well-being and depression. OC-users in both cohorts showed elevated basal oxytocin, lower ACTH, estradiol, progesterone and testosterone compared with non-OC users. Satisfaction With Life Score (SWLS) was higher in OC -users compared to non-OC users, with no differences in the Beck Depression Score (BDI) and Positive And Negative Affect Schedule (PANES). In conclusion, our data show alterations in hormone levels and SWLS in response to OC.
... Only female participants were included into the study as the effects of oxytocin on brain activation have been shown to differ between the sexes [25,26], and although this choice limits generalizability of the findings it enhances statistical power. Moreover, only participants who used oral contraceptives were included in the trial to have a better control of menstrual cycle related hormonal changes [27]. Participants were scanned in the weeks when they used oral contraceptives, not in their stop week. ...
Article
Full-text available
It has been demonstrated that secretion of several hormones can be classically conditioned, however, the underlying brain responses of such conditioning have never been investigated before. In this study we aimed to investigate how oxytocin administration and classically conditioned oxytocin influence brain responses. In total, 88 females were allocated to one of three groups: oxytocin administration, conditioned oxytocin, or placebo, and underwent an experiment consisting of three acquisition and three evocation days. Participants in the conditioned group received 24 IU of oxytocin together with a conditioned stimulus (CS) during three acquisition days and placebo with the CS on three evocation days. The oxytocin administration group received 24 IU of oxytocin and the placebo group received placebo during all days. On the last evocation day, fMRI scanning was performed for all participants during three tasks previously shown to be affected by oxytocin: presentation of emotional faces, crying baby sounds and heat pain. Region of interest analysis revealed that there was significantly lower activation in the right amygdala and in two clusters in the left superior temporal gyrus in the oxytocin administration group compared to the placebo group in response to observing fearful faces. The activation in the conditioned oxytocin group was in between the other two groups for these clusters but did not significantly differ from either group. No group differences were found in the other tasks. Preliminary evidence was found for brain activation of a conditioned oxytocin response; however, despite this trend in the expected direction, the conditioned group did not significantly differ from other groups. Future research should, therefore, investigate the optimal timing of conditioned endocrine responses and study whether the findings generalize to other hormones as well.
... Since sex-dependent effects of OXT have been reported by previous studies (Gao et al., 2016;Scheele et al., 2014), it is possible that OXT effects on self-serving lying might be different in females. However, no females were included due to possible interferences with their hormonal status depending on the individual phase of the menstrual cycle or intake of hormonal contraceptives (see, e.g., fluctuations in OXT plasma levels depending on menstrual cycle and contraceptives (Salonia et al., 2005) or other OXT treatment studies on females discussing this problem (Scheele et al., 2014;Theodoridou, Rowe, Penton-Voak, & Rogers, 2009) These results not only led to the conclusion that the characterization of OXT as "cuddle hormone" might not be completely true, but also that several moderating factors exist, which explain the various effects of OXT administration (Bartz et al., 2011;Shamay-Tsoory & Abu-Akel, 2016 OXT administration studies suffer from drawbacks such as underpowered sample sizes. Also, the possibility of publication bias, as well as the questions about whether, and how much OXT enters the brain represent important topics in the field of OXT research (Leng & Ludwig, 2016;Walum, Waldman, & Young, 2016). ...
Article
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Introduction: The effects of intranasal administration of the neuropeptide oxytocin on social cognition and behavior are highly specific. Potentially situational and personal variables influence these effects. The aim of the present study was to investigate effects of oxytocin administration on self-serving lying, including situational effects. Methods: A total of 161 adult males participated in a randomized double-blind placebo-controlled between-subject intranasal oxytocin administration (24 international units) study. Self-serving lying was assessed using three subsequent rounds of the die-in-a-cup paradigm, in which different degrees of lying can be implemented by the participants that can be determined on group level. Results: Oxytocin administration seemed to promote self-serving lying, particularly in the third (last) round and only to a certain degree (not to the maximum possible). Conclusions: Our findings demonstrate that oxytocin administration can promote self-serving lying when given repeated opportunities to lie. Moreover, exploratory results presented in the Supplementary Material indicate that the sensitivity to the effects of intranasal oxytocin in this domain might be moderated by individual differences in the oxytocin receptor gene.
... One of the underlying physiological mechanisms of the post-orgasmic prolactin surge might be the known increase of oxytocin throughout sexual arousal with a peak during orgasm [37][38][39][40]. One case report showed a positive effect of exogenous peripheral oxytocin exposure on sexual satisfaction [41]. ...
Article
Research question: What are the specific characteristics of sexual activity in women with endometriosis compared with women without endometriosis? Design: Multicentre case control study. Participants were recruited from university hospitals, district hospitals and doctor's offices in Germany, Switzerland and Austria. A total of 565 women with endometriosis were pair-matched to 565 control women by age and ethnic background. Diagnosis of endometriosis was confirmed by histology, and disease stage was classified according to American Society for Reproductive Medicine criteria. Data on sexuality were collected using selected questions from the Brief Index of Sexual Function and the Sexual History Form. Results: Altogether, 69.1% of women with endometriosis and 77.8% of control women engaged in sexual activity during the month before the study period (P < 0.001). Overall, 42.3% of endometriosis-affected women and 30.5% of the control women desired a higher frequency of sexual activity (P < 0.001). Petting, foreplay and vaginal sexual intercourse were reported to be practised less often by women with endometriosis. Frequencies for masturbation, reciprocal masturbation, oral and anal sex were similar in both groups. Dyspareunia was negatively associated with sexual activity (OR 2.42, 95% CI 1.26 to 4.63), whereas chronic pain showed no association with sexual activity (OR 1.35, 95% CI 0.93, 1.96). Conclusions: Women with endometriosis have lower frequencies of petting, foreplay and vaginal sexual intercourse than control women; this difference has to be attributed, at least in part, to dyspareunia. Potentially pain-free sexual options are used to a limited degree. As endometriosis-affected women desire higher levels of sexual activity, sexual counselling should be included in medical support.
... They were invited preferably in the luteal phase of their (self-reported) menstrual cycle in order to control for influences of menstrual cycle. During the luteal phase, plasma oxytocin levels are lower (Salonia et al., 2005) . Women were asked about the date of their last menstruation and this information was used to schedule the lab session. ...
Article
Full-text available
Oxytocin is considered a biological mechanism underlying stress-protective effects of positive social interactions. It is assumed to underlie the women-specific tend-and-befriend response to stress, although few studies have tested this assertion with female samples. The aim of the present study was, therefore, to test whether oxytocin enhances stress-protective effects of social support during stress in women, taking into account the moderating role of childhood adversity. The sample consisted of 180 female undergraduate students who had reported on experiences of childhood abuse and how often their mother used love withdrawal as an insensitive disciplinary strategy. Women participated in a virtual version of the Trier Social Stress Test (TSST) and were randomly assigned to receive 24 IU oxytocin or a placebo and to receive support or no support from a female friend (sub-groups N = 45). Results showed that oxytocin reduced heart rate variability during the TSST in participants who received support, possibly indicating that oxytocin increases attention and stimulates a challenge motivational state in the presence of a friend. In addition, we found that, in the presence of a friend, oxytocin reduced state anxiety levels and cortisol levels after the TSST, but only in women with higher levels of adverse childhood experiences. Our findings may indicate that oxytocin is a neurobiological means to attain and benefit from social support under stressful circumstances, which may be particularly adaptive for women with a history of adversity. Thus, oxytocin may function as motivator for affiliative disposition during stress exposure in women with a history of childhood adversity. Results should be replicated in clinical samples.
... Ninety-nine healthy women participated in the study. Only women who were taking oral contraceptives were included because they have stable levels of oxytocin during the cycle (26). All women were tested while in their pill weeks and not in their stop weeks. ...
Article
Full-text available
Objective: Evidence exists that placebo effects may influence hormone secretion. However, only few studies examined placebo effects in the endocrine system, including oxytocin placebo effects. We studied whether it is possible to trigger oxytocin placebo effects using a classical conditioning paradigm. Methods: Ninety-nine females were assigned to a conditioned, control or drug-control group. In the two-phase conditioning paradigm, participants in the conditioned and drug-control groups received an oxytocin nasal spray combined with a distinctive smell (conditioned stimulus, CS) during three acquisition days, while the control group received placebo spray. Subsequently, the conditioned and control groups received placebo spray with the CS and the drug-control group- oxytocin spray during three evocation days. Salivary oxytocin was measured several times during each day. Pain sensitivity and facial evaluation tests previously used in oxytocin research were also administered. Results: On evocation day 1, in the conditioned group oxytocin significantly increased from baseline to 5 minutes after CS (B[slope]=19.55, S.E.=5.88, p<.001) and remained increased from 5 to 20 (B=-10.42, S.E.=5.81, p=.071) and 50 minutes (B=-0.70, S.E.=3.37, p=.84). On evocation day 2, a trend for increase in oxytocin was found at 5 minutes (B=15.22, S.E.= 8.14, p=0.062). No placebo effect was found on evocation day 3 (B=3.57, S.E.=3.26, p=0.28). Neither exogenous nor conditioned oxytocin affected pain or facial tasks. Conclusions: Results indicate that oxytocin release can be conditioned and that this response extinguishes over time. Triggering hormonal release by placebo manipulation offers various clinical possibilities, such as enhancing effects of pharmacological treatments or reducing dosages of medications. Trial registration: The study was registered as a clinical trial on www.trialregister.nl (number NTR5596).
... Only female participants were included into the study as the effects of oxytocin on brain activation have been shown to differ between the sexes [25,26], and although this choice limits generalizability of the findings it enhances statistical power. Moreover, only participants who used oral contraceptives were included in the trial to have a better control of menstrual cycle related hormonal changes [27]. Participants were scanned in the weeks when they used oral contraceptives, not in their stop week. ...
Preprint
Full-text available
It has been demonstrated that secretion of several hormones can be classically conditioned, however, the underlying brain responses of such conditioning have never been investigated before. In this study we aimed to investigate how oxytocin administration and classically conditioned oxytocin influence brain responses. In total, 88 females were allocated to one of three groups: oxytocin administration, conditioned oxytocin, or placebo, and underwent an experiment consisting of three acquisition and three evocation days. Participants in the conditioned group received 24 IU of oxytocin together with a conditioned stimulus (CS) during three acquisition days and placebo with the CS on three evocation days. The oxytocin administration group received 24 IU of oxytocin and the placebo group received placebo during all days. On the last evocation day, fMRI scanning was performed for all participants during three tasks previously shown to be affected by oxytocin: presentation of emotional faces, crying baby sounds and heat pain. Region of interest analysis revealed that there was significantly lower activation in the right amygdala and in two clusters in the left superior temporal gyrus in the oxytocin administration group compared to the placebo group in response to observing fearful faces. The activation in the conditioned oxytocin group was in between the other two groups for these significant clusters but did not significantly differ from either group. No group differences were found in the other tasks. The findings carefully suggest that a conditioned response in brain activity was observed, however the conditioned group did not significantly differ from the other groups. Future research should therefore investigate the optimal timing of conditioned endocrine responses and study whether the findings generalize to other hormones as well.
... Plasma OT assessments were conducted within the follicular phase, between the 5 th and 12 th day of the menstrual cycle, because of the optimal stability of gonadal hormones during this period [29]. Participants fasted for eight hours before hormonal measurements. ...
Article
Obesity is a prevalent public health problem, and food addiction (FA) is one of the most controversial factors in its management. Therefore, this study was designed to validate an FA questionnaire for Iranian women with obesity and to determine the prevalence of FA and its associations with plasma oxytocin (OT) levels as well as anthropometric and dietary measurements. In this descriptive-analytical study, 450 adult women with obesity were included. The prevalence of FA was determined with a valid Yale food addiction scale (YFAS). Macronutrient intakes were measured by a valid semi-quantitative food frequency questionnaire (FFQ). In addition, plasma OT was measured after eight hours of fasting. In this study, the prevalence of FA was 26.2% in women with obesity. In comparison with class I obesity, the odds ratios (95% CI) of FA for class II and class III obesity were 2.5 (CI: 1.29–5.09) and 3.3 (CI: 1.69–6.4) respectively. Dietary intakes of energy, protein, carbohydrate, fat, saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, and cholesterol were significantly higher in food-addicted (FAD) women compared to non-food-addicted (NFA) ones (p < 0.001). Moreover, plasma OT level was lower in FAD women with obesity than in NFA subjects (p = 0.02). In conclusion, the results of this study indicate that FA is prevalent in Iranian women with obesity. In addition, FA is related to obesity severity, dietary intakes of energy, carbohydrate, protein, fat, cholesterol, and plasma OT level.
... The consideration of estrogen status is important when examining OT dynamics in females because estradiol stimulates OT release and endogenous OT levels are affected by menstrual cycle phase, with lower levels in the early to mid-follicular phase (when estradiol levels are low), and a peak at ovulation (when estradiol levels are high) (27,(45)(46)(47)(48)(49). Although we previously demonstrated lower fasting and postprandial OT levels in healthy females in the early to mid-follicular phase compared with other menstrual cycle phases (27), we did not observe any differences in fasting or postprandial OT levels in females with AN/atypical AN according to estrogen status, despite significantly higher serum estradiol levels in AN-HE vs AN-LE. ...
Article
Context: In healthy females, oxytocin levels decrease post-meal, corresponding to increased satiety. The postprandial response of oxytocin in females with anorexia nervosa (AN)/atypical AN is unknown. Objectives: To determine the pattern of postprandial serum oxytocin levels in females with AN/atypical AN, relationship with appetite, and impact of weight, eating behavior, and endogenous estrogen status. Design: Cross-sectional. Setting: Clinical research center. Participants: 67 women [36 with AN (<85% expected body weight (EBW)); 31 with atypical AN (≥85% EBW)], age 22.4±0.9 (mean±SEM) years, categorized by weight, restricting vs. binge/purge behavior, and estrogen status. Interventions: Standardized mixed meal. Main outcome measurements: Blood sampling for oxytocin occurred fasting and 30, 60, and 120 minutes post-meal. Subjective appetite was assessed using Visual Analogue Scales. Results: In females with AN/atypical AN, oxytocin levels decreased from fasting to 60 (p=0.002) and 120 (p=0.005) minutes post-meal. The decrease in oxytocin from fasting to 120 minutes was greater in females with atypical AN than AN (p=0.027) and did not differ by restricting vs. binge/purge behavior or estrogen status. Controlling for caloric intake, the decrease in oxytocin was inversely related to the decrease in hunger post-meal in females with atypical AN (p=0.04). Conclusions: In females with AN/atypical AN, oxytocin levels decrease post-meal, as established in healthy females. Weight, but not restricting versus binge/purging nor endogenous estrogen status, impacts postprandial oxytocin levels. The postprandial change in serum oxytocin levels is related to appetite in females with atypical AN only, suggesting a disconnect between oxytocin secretion and appetite in the undernourished state.
Chapter
The endocrine and neuroendocrine system in pregnancy involves highly complex maternal, fetal and placental mechanisms, which are critical for the maintenance of pregnancy, the timing of parturition, for fetal growth and protection from adverse fetal programming. This timely book summarizes the different endocrine aspects related to pregnant women, describing how hormones regulate physiological homeostasis and influence the pathogenesis of disease. The first section of the book covers the role of specific hormones in detail, including oxytocin, hCG and estrogen. The second section discusses gestational disorders such as diabetes, hypertensive disorders and preeclampsia and how the involvement of hormones has clinical implications for management. Best practice for management of endocrine disorders, which can negatively impact pregnancy, such as thyroid disease and obesity, is also reviewed. This book is essential for clinicians and scientists looking to gain knowledge of the role of hormones in pregnancy and how they can best support patients.
Article
Introduction: Sexual dysfunction (SD) is a symptom of depression in ≈70% of patients presenting with major depressive disorder (MDD). Antidepressant medications (AD) and adjunctive treatments may further contribute to SD and complicate evaluation and management. Areas covered: A systematic literature search of PubMed, Ovid MEDLINE and Cochrane databases for MDD, SD, classes of antidepressants, etc. was performed with a focus on 2014 to June 2021. SSRIs are associated with 70% treatment-emergent sexual dysfunction (TESD), SNRIs and tricyclics have rates of TESD of 40 - 45%, and antidepressant medications without SRI effects or with additional unique mechanisms of action have rates similar to placebo (<10%). Appropriate assessment at baseline and throughout treatment, consideration of patient preferences in prescribing, addressing modifiable factors (comorbid medical/psychiatric conditions, substances, relationship difficulties), and utilizing management strategies of switching to an AD with less SD, adding an antidote/adjunctive therapy or lowering the dose are discussed. Expert opinion: MDD and antidepressant treatment contribute to SD in a high percentage of patients. Treating to remission reduces SD as a symptom of depression. Frequent assessment and targeted management strategies may be effective in preventing or addressing SD. Secondary outcomes like impact on adherence, relationships and self-image should also be considered.
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Trust is essential for establishing and maintaining cooperative behaviors between individuals and institutions in a wide variety of social, economic, and political contexts. This book explores trust through the lens of neurobiology, focusing on empirical, methodological, and theoretical aspects. Written by a distinguished group of researchers from economics, psychology, human factors, neuroscience, and psychiatry, the chapters shed light on the neurobiological underpinnings of trust as applied in a variety of domains. Researchers and students will discover a refined understanding of trust by delving into the essential topics in this area of study outlined by leading experts.
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The neuropeptide oxytocin (OXT) has been linked to interpersonal trust. While initial behavioral studies demonstrated a facilitating effect of OXT on trusting behavior, more recently these findings have been challenged. In this chapter we review the literature reporting two approaches that are used to evaluate OXT’s effects: exogenous OXT administration and the investigation of the endogenous OXT system. With respect to trust, we report results from studies investigating trusting behavior, mostly using economic games, and studies looking on the intention to trust other individuals. Overall, clear evidence for a direct trust-promoting effect of OXT as proposed by early studies cannot be found. Instead, there is evidence that the relationship between OXT and trust is modulated by manifold contextual factors that are closely interrelated, e.g., social affiliation, personality traits, gender, mental disorders, and genetic disposition. Furthermore, it could be argued that the effect of OXT on trust is not a specific one but only a subphenomenon of the more general prosocial effect of the neuropeptide. Future research should aim to conceive models of the OXT–trust connection considering the interactions between genes, brain functioning, and the environment, advancing the knowledge of understanding interpersonal trust.
Article
Male and female stump-tailed macaques (Macaca arctoides) form close relationships akin to human friendships. Oxytocin and vasopressin modulate these and other social relationships and reproductive behavior and physiology in various mammal species. Besides the behavioral effects of oxytocin, this hormone plays an essential role in the ejaculatory process, favoring sperm transport upward the female reproductive tract. Therefore, we investigated the influence of friendships on postcopulatory serum levels of oxytocin and vasopressin in the stump-tailed macaque (Macaca arctoides). In addition, we searched for a correlation between this kind of social relationship and sperm transport in the vagina during the periovulatory and luteal phases. Six female and six male adult macaques having different friendship indices served as experimental animals. Allocated in 57 mating pairs combinations, these animals were allowed to copulate once in the luteal and periovulatory phases. Blood samples were collected from each animal finishing copulation to measure oxytocin and vasopressin. Afterward, we profoundly sedated the females and collected three semen samples from the vagina every 10 min to perform spermatobioscopies. Males' post-copulation oxytocin values increased along with the friendship index, while vasopressin behaves oppositely. Sperm concentration and immotile and motile sperm decreased from one sample to another as male-female closeness increased. Finally, in the periovulatory phase, only in the first vaginal sample, sperm velocities significantly increased with friendship indices. Our results showed that in stump-tailed macaques, heterosexual friendships promote higher postcopulatory oxytocin concentrations and better physiological conditions to males, which probably enhance reproductive success.
Article
Alcohol use disorder (AUD) is a severe illness, for which we lack sufficient mechanistic understanding. Preliminary evidence associates AUD with the oxytocin (OXT) system. Here we investigated alterations in endogenous OXT blood concentrations in patients with AUD and their association with alcohol drinking and prospective course. In sex-separated analyses, OXT serum concentrations of 200 in-patients with AUD (56.5% male; baseline, 24–72 h of abstinence) were compared with those of 240 age-matched healthy controls (55.4% male), investigated longitudinally (follow-up, 5 days later), and tested for associations with alcohol drinking behavior and prospective 24-month alcohol-related hospital readmissions. At baseline, the patients showed increased OXT concentrations relative to controls (men, 156%, P < 0.001; women, 124%, P = 0.002). The elevations normalized at follow-up. In male patients, baseline OXT concentrations correlated positively with alcohol concentration at admission, the amount of alcohol consumption per drinking year, and the number of previous withdrawal treatments (Rho > 0.195, P < 0.044). In beverage type-specific analysis, baseline OXT concentrations correlated with liquor consumption positively in male and negatively in female patients (|Rho| > 0.277, P < 0.017). Higher baseline OXT concentrations predicted more readmissions and fewer days to the first readmission (|Rho| > 0.185, P < 0.050) in male patients. This study provides novel and sex-separated insights into the role of the OXT system in AUD. We identified a mechanism that might underlie the sex-separated choice of beverage type and established that increased OXT concentrations during early abstinence predict a worse outcome in male patients with AUD.
Article
To further understand protective mechanisms to prevent post-traumatic stress disorder or assist recovery from psychological trauma, this study investigated whether pharmacological and psychological activation of a secure attachment representation elicits higher felt-security and a related response pattern of reduced physiological arousal and increased parasympathetic activation; and whether it protects individuals from developing intrusions and experiencing distress in the week following exposure to a trauma film. Using a double-blind, experimental mixed factorial design, 101 volunteers received either oxytocin or placebo and either secure attachment or neutral priming before watching a trauma film. We measured felt security as an indicator of the strength of activation of a secure attachment representation, skin conductance and heart rate as indicators of physiological arousal, and high frequency heart rate variability as an indicator of parasympathetic activation during the priming and the film. Participants then completed a seven-day intrusion diary. Secure attachment priming, but not oxytocin administration or the combination of both, was associated with reduced physiological arousal and increased parasympathetic activity during priming. Although secure attachment priming was not related to the absolute number of intrusions or to less perceived distress or physiological arousal during the trauma film, it was associated with lower intrusion-related distress in the 7-days post-testing. Our findings extend previous research that suggests the importance of interventions that address intrusion-related distress for recovery from trauma, and suggest a promising role for secure attachment priming in trauma-focused psychological therapies. We contribute to the growing literature that finds that higher subjective distress during a trauma is associated with higher intrusion-related distress. We discuss theoretical implications and possible mechanisms through which secure attachment priming may exert potential beneficial effects.
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The chapter presents data on the development of breast structure and function during various periods of a woman’s life: in the prenatal period, in the first 2 years after birth, during puberty, and during pregnancy. The onset of breast development, as well as early morphogenesis in the embryo, is due to mesenchymal-epithelial interaction with the help of autocrine/paracrine growth factors. The mammary glands of human fetuses achieve a rather high degree of development in structural and functional relation, by the time of birth. After birth, infant mammary glands for some time begin to function while continuing their development. The most intensive development of the breast begins with puberty and the appearance of a menstrual cycle in girls. The development and functioning of the mammary glands changes during this cycle under the influence of the steroid hormones, prolactin and oxytocin. Final breast development occurs during pregnancy and is highly dependent on reproductive and metabolic hormones.
Article
Ovarian hormones exert an influence on social information processing, in which, however, the exact roles of estradiol and progesterone remain unclear. This study examines the specific influences of these two ovarian hormones on social information processing across the menstrual cycle using the emotional face flanker task and attentional network test (ANT). Twenty-six naturally cycling, healthy women were tested thrice: during menses, in the follicular phase, and in the luteal phase. In the emotional face flanker task, a significant positive relation was found between progesterone levels and reaction times (RTs) for sad faces, suggesting that high progesterone levels may activate the social monitoring system and allocate more attention to the social stimulus, which benefits individuals’ survival and adaptation. In the ANT, a significant increase was found in RTs and accuracy during the luteal phase, suggesting that luteal women increase this accuracy by exerting a relatively conservative strategy of allocating more attention to the targets. Taken together, these findings indicate that high levels of progesterone may facilitate social information processing by optimizing attention allocation. Moreover, overactivation of the social monitoring system may make women more susceptible to stressors and promote affective disturbances, which may provide underlying pathophysiology of the premenstrual dysphoric disorder.
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Dieses Kapitel behandelt neurochemische Einflüsse auf das Wohlbefinden mit dem Fokus auf die Substanzen Dopamin und Oxytocin. Dopamin als Neurotransmitter und Oxytocin als Neuropeptid werden wichtige modulatorische Einflüsse auf das Erleben positiver Emotionen zugeschrieben. Während Dopamin in erster Linie mit Motivation und Belohnung assoziiert wird, spielt Oxytocin insbesondere eine wichtige Rolle bei der Entstehung von prosozialen Emotionen wie Geborgenheit und interpersoneller Nähe. Schon auf neurophysiologischer Ebene zeigt die Verschränkung beider Systeme mit einer Kolokalisation von Dopamin- und Oxytocinrezeptoren in wichtigen Regionen des Belohnungssystems, dass beide Aspekte positiver Emotionalität nicht unabhängig zu betrachten sind. Während Oxytocin über eine Dämpfung von Angst und Stress das Erleben sozialer Nähe und Bindung erlaubt, erhöht Dopamin die Motivation, sich positiven Reizen und Situationen anzunähern.
Article
Native circulating oxytocin (OT) levels in non-pregnant/non-lactating/non-medicated humans are very low (≤8 pg/mL). The lower limit of detection (LLOD) of our previous liquid chromatography mass spectrometry (LC-MS) method (10-25 pg/mL) precluded their quantification in serum and urine. Thus, we sought to improve the LC-MS sensitivity of OT measurements in these matrices by hydrophobic tagging and solid phase extraction (SPE). In the former approach, OT was reduced then alkylated with N-alkyl acetamide (C12, C14, C16, and C18) tags or derivatized using sulfonyl chloride-based reagents. In the latter approach, native OT in serum and urine was concentrated by offline SPE using gradient acetonitrile washings after first crashing with acetonitrile. Peak urinary eluate fractions were further concentrated online then analyzed by orbitrap-based LC-MS with electrospray ionization. All hydrophobic OT derivatives had lower sensitivity than native OT. Washing with a water-acetonitrile gradient during SPE improved the LLOD of OT in spiked serum to 2.5 pg/mL while adding a subsequent online-concentration step improved the LLOD in spiked urine to 1-5 pg/mL and allowed us to detect OT in urine from lactating women. We were unable to improve the sensitivity of OT measurements by hydrophobic tagging or by derivatization using sulfonyl chloride-based reagents. However, we were successful in improving the sensitivity of native OT measurements in serum and urine 2- and 5-fold, respectively, from our previous orbitrap-based LC-MS method. Offline SPE was mandatory for both matrices and a subsequent online-concentration step was required for urine.
Article
Introduction: Hormonal contraception is available worldwide in many different forms. Fear of side effects and health concerns are among the main reasons for not using contraceptives or discontinuing their use. Although the safety and efficacy of contraceptives have been extensively examined, little is known about their impact on female sexual function, and the evidence on the topic is controversial. Aim: To review the available evidence about the effects of hormonal contraceptives on female sexuality in order to provide a position statement and clinical practice recommendations on behalf of the European Society of Sexual Medicine. Methods: A comprehensive review of the literature was performed. Main outcome measure: Several aspects of female sexuality have been investigated, including desire, orgasmic function, lubrication and vulvovaginal symptoms, pelvic floor and urological symptoms, partner preference, and relationship and sexual satisfaction. For each topic, data were analyzed according to the different types of hormonal contraceptives (combined estrogen-progestin methods, progestin-only methods, and oral or non-oral options). Results: Recommendations according to the Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence criteria and specific statements on this topic, summarizing the European Society of Sexual Medicine position, were developed. Clinical implications: There is not enough evidence to draw a clear algorithm for the management of hormonal contraception-induced sexual dysfunction, and further studies are warranted before conclusions can be drawn. A careful baseline psychological, sexual, and relational assessment is necessary for the health care provider to evaluate eventual effects of hormonal contraceptives at follow-up. Strengths & limitations: All studies have been evaluated by a panel of experts who have provided recommendations for clinical practice. Conclusion: The effects of hormonal contraceptives on sexual function have not been well studied and remain controversial. Available evidence indicates that a minority of women experience a change in sexual functioning with regard to general sexual response, desire, lubrication, orgasm, and relationship satisfaction. The pathophysiological mechanisms leading to reported sexual difficulties such as reduced desire and vulvovaginal atrophy remain unclear. Insufficient evidence is available on the correlation between hormonal contraceptives and pelvic floor function and urological symptoms. Both S, Lew-Starowicz M, Luria M, et al. Hormonal Contraception and Female Sexuality: Position Statements from the European Society of Sexual Medicine (ESSM). J Sex Med 2019;16:1681-1695.
Article
A growing literature associates the neuropeptides oxytocin (OT) and arginine vasopressin (AVP) with affiliative and cognitive outcomes. The majority of this work in humans, however, considers these neuropeptides separately. Also, despite evidence that OT and AVP interact with gonadal hormones, still warranted is an examination of sex and age variations in endogenous neuropeptide levels, their interrelations, and their functional relationships with attachment and cognition in humans. This study measured endogenous plasma OT and AVP levels in generally healthy young (18-31 years) and older (63-81 years) men and women to (i) determine levels of and interrelations between OT and AVP; (ii) explore functional relationships with self-reported attachment (attachment anxiety and avoidance) and performance-based cognition (processing speed, verbal memory); and (iii) identify variations in these effects by sex and age. We observed sex- and age-differential patterns of results: Women had higher plasma OT levels than men and older adults had higher plasma AVP levels than young adults. The two neuropeptides were highly negatively intercorrelated across all groups. Functionally, higher AVP levels were associated with greater attachment anxiety and higher OT and lower AVP levels were associated with faster sensorimotor processing speed, with sex and age moderating these effects. This integrated approach identifies variations in endogenous peripheral neuropeptide levels in humans, supporting their sex- and age-specific role as "difference makers" in attachment and cognition.
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This book is about the erotic power of the breast to improve our sex lives and enhance our health. Breast sex is unique to humans. It is not practiced by other species, and because of its uniqueness, it deserves special consideration. The breast has been, from the beginning of human culture, important to our sexuality, enabling deep intimacy. With breast sex, woman began to extend to her mate the same love that she extends to her child, and mates began to live together, bringing about the human family. Not only sex but health is also improved with breast functionality. Dr. Timothy G. C. Murrell, a family medicine physician from Australia, investigated how using the breast sexually might result in expelling carcinogens from the body. Related to this, studies have shown that breastfeeding reduces the risk of breast cancer. Alice Rossi, PhD, discusses the relationship between sexuality and maternity and how oxytocin, known as the love hormone or the bonding hormone, arises in the body with both breast sex and breastfeeding and contributes to our pleasure and our health. Breast sexuality is common to everyday life in many different cultures of the world, and a myriad of related practices are recounted here from Africa, Asia, Europe, Australia, and North and South America. Breast sex is popular around the globe because it enables ease of sexual satisfaction for women, overcoming a problem that many women acknowledge. This book tells the story!
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The purpose of this study was to determine whether plasma oxytocin (OT) levels change during human sexual responses and, if so, to demonstrate the temporal pattern of change. Plasma OT levels were measured by RIA before, during, and after private self-stimulation to orgasm in normal men (n = 9) and women (n = 13). Blood samples were collected continuously through indwelling venous catheters. The subjects pressed a signal to indicate the start and finish of orgasm/ejaculation. Objective assessment of sexual arousal and orgasm was obtained by measuring blood-pulse amplitude and electromyographic activity, recorded continuously throughout testing from an anal device containing a photoplethysmograph and electromyograph electrodes connected to a polygraph located in an adjacent room. These measures allowed collection of data from men and women of changes in blood flow and muscle activity in the lower pelvic/pubic area. Plasma OT levels increased during sexual arousal in both women and men and were significantly higher during orgasm/ejaculation than during prior baseline testing. We suggest that the temporal pattern of secretion could be related to smooth muscle contractions of the reproductive system during orgasm.
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The oxytocin and prolactin responses to suckling were measured in 10 women in early (n = 5) and established lactation (n = 5). Oxytocin was released in a pulsatile manner during suckling in all women, but the response was not related to milk volume, prolactin response, or parity of the mother. In all 10 women plasma oxytocin concentrations increased three to 10 minutes before suckling began. In five women this occurred in response to the baby crying, in three it coincided with the baby becoming restless in expectation of the feed, while in two it corresponded with the mother preparing for the feed. There was no prolactin response to stimuli other than stimulation of the nipple associated with suckling. These results clearly indicate that the milk ejection reflex, with release of oxytocin, occurs in most women before the tactile stimulus of suckling. A second release of oxytocin follows in response to the suckling stimulus itself. Thus it is important that care is taken to protect breast feeding mothers from stress not only during suckling but also immediately before nursing, when conditioned releases of oxytocin will occur.
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Our previous studies have shown that stimulation of the anterior ventral third ventricular region increases atrial natriuretic peptide (ANP) release, whereas lesions of this structure, the median eminence, or removal of the neural lobe of the pituitary block ANP release induced by blood volume expansion (BVE). These results indicate that participation of the central nervous system is crucial in these responses, possibly through mediation by neurohypophysial hormones. In the present research we investigated the possible role of oxytocin, one of the two principal neurohypophysial hormones, in the mediation of ANP release. Oxytocin (1-10 nmol) injected i.p. caused significant, dose-dependent increases in urinary osmolality, natriuresis, and kaliuresis. A delayed antidiuretic effect was also observed. Plasma ANP concentrations increased nearly 4-fold (P < 0.01) 20 min after i.p. oxytocin (10 nmol), but there was no change in plasma ANP values in control rats. When oxytocin (1 or 10 nmol) was injected i.v., it also induced a dose-related increase in plasma ANP at 5 min (P < 0.001). BVE by intra-atrial injection of isotonic saline induced a rapid (5 min postinjection) increase in plasma oxytocin and ANP concentrations and a concomitant decrease in plasma arginine vasopressin concentration. Results were similar with hypertonic volume expansion, except that this induced a transient (5 min) increase in plasma arginine vasopressin. The findings are consistent with the hypothesis that baroreceptor activation of the central nervous system by BVE stimulates the release of oxytocin from the neurohypophysis. This oxytocin then circulates to the right atrium to induce release of ANP, which circulates to the kidney and induces natriuresis and diuresis, which restore body fluid volume to normal levels.
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To estimate the probability of remaining free of AIDS for up to 25 years after infection with HIV by extrapolation of changes in CD4 lymphocyte count. Cohort study of subjects followed from time of HIV seroconversion until 1 January 1993. Creation of model by using extrapolated linear regression slopes of CD4 count to predict development of AIDS after 1993. Regional haemophilia centre in teaching hospital. 111 men with haemophilia infected with HIV during 1979-85. Median length of follow up 10.1 years, median number of CD4 counts 17. The model was not fitted for three men because only one CD4 measurement was available. Development of AIDS. From 1989 prophylaxis against candida and Pneumocystis carinii pneumonia and antiretroviral drugs when CD4 count fell below 200 x 10(6)/l. 44 men developed AIDS up to 1 January 1993. When AIDS was defined as a CD4 count of 50 x 10(6)/l the model predicted that 25% (95% confidence interval 16% to 34%) would survive for 20 years after seroconversion and 18% (11% to 25%) for 25 years. Changing the CD4 count at which AIDS was assumed to occur did not alter the results. Younger patients had a higher chance of 20 year survival than older patients (32% (12% to 52%) for those aged < 15, 26% (14% to 38%) for those aged 15-29, and 15% (0% to 31%) for those aged > or = 30). These results suggest that even with currently available treatment up to a quarter of patients with HIV infection will survive for 20 years after seroconversion without developing AIDS.
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Oxytocin, a neurohypophyseal hormone, has been traditionally considered essential for mammalian reproduction. In addition to uterine contractions during labor and milk ejection during nursing, oxytocin has been implicated in anterior pituitary function, paracrine effects in the testis and ovary and the neural control of maternal and sexual behaviors. To determine the essential role(s) of oxytocin in mammalian reproductive function, mice deficient in oxytocin have been generated using embryonic stem cell technology. A deletion of exon 1 encoding the oxytocin peptide was generated in embryonic stem cells at a high frequency and was successfully transmitted in the germ line. Southern blot analysis of genomic DNA from homozygote offspring and in situ hybridization with an exonic probe 3' of the deletion failed to detect any oxytocin or neurophysin sequences, respectively, confirming that the mutation was a null mutation. Mice lacking oxytocin are both viable and fertile. Males do not have any reproductive behavioral or functional defects in the absence of oxytocin. Similarly, females lacking oxytocin have no obvious deficits in fertility or reproduction, including gestation and parturition. However, although oxytocin-deficient females demonstrate normal maternal behavior, all offspring die shortly after birth because of the dam's inability to nurse. Postpartum injections of oxytocin to the oxytocin deficient mothers restore milk ejection and rescue the offspring. Thus, despite the multiple reproductive activities that have been attributed to oxytocin, oxytocin plays an essential role only in milk ejection in the mouse.
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In terms of reproductive success the quality and duration of maternal care exhibited by any particular species is of paramount importance, and yet compared with the amount of research studying the control of reproductive cycles, sexual behaviour, and fertility, it has historically received considerably less attention. However, we are now beginning to understand how the brain is organised to mediate this complex behaviour and how its expression is orchestrated by different hormonal and neurochemical factors. This review summarises a series of neuroanatomical, electrophysiological, in vivo sampling and behavioural neuropharmacological experiments carried out in sheep. These have attempted to define the neural circuitry and hormonal neurotransmitter systems involved both in the control of maternal behaviour per se and in the selective olfactory recognition of lambs, which is the basis of an exclusive emotional bond between mother and offspring.
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Oxytocin is clearly involved in human reproduction and serves an important role in sexual arousal. Oxytocin serum levels were measured before and after sexual stimulation in 12 healthy women. Values of oxytocin 1 min after orgasm were significantly higher (p < 0.05) than baseline levels. This finding supports the hypothesis that oxytocin plays a major part in human sexual response both in neuroendocrine function and postcoital behavior.
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This article presents the development of a brief, self-report measure of female sexual function. Initial face validity testing of questionnaire items, identified by an expert panel, was followed by a study aimed at further refining the questionnaire. It was administered to 131 normal controls and 128 age-matched subjects with female sexual arousal disorder (FSAD) at five research centers. Based on clinical interpretations of a principal components analysis, a 6-domain structure was identified, which included desire, subjective arousal, lubrication, orgasm, satisfaction, and pain. Overall test-retest reliability coefficients were high for each of the individual domains (r = 0.79 to 0.86) and a high degree of internal consistency was observed (Cronbach's alpha values of 0.82 and higher) Good construct validity was demonstrated by highly significant mean difference scores between the FSAD and control groups for each of the domains (p < or = 0.001). Additionally, divergent validity with a scale of marital satisfaction was observed. These results support the reliability and psychometric (as well as clinical) validity of the Female Sexual Function Index (FSFI) in the assessment of key dimensions of female sexual function in clinical and nonclinical samples. Our findings also suggest important gender differences in the patterning of female sexual function in comparison with similar questionnaire studies in males.
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Oxytocin (OT), a nonapeptide, was the first hormone to have its biological activities established and chemical structure determined. It was believed that OT is released from hypothalamic nerve terminals of the posterior hypophysis into the circulation where it stimulates uterine contractions during parturition, and milk ejection during lactation. However, equivalent concentrations of OT were found in the male hypophysis, and similar stimuli of OT release were determined for both sexes, suggesting other physiological functions. Indeed, recent studies indicate that OT is involved in cognition, tolerance, adaptation and complex sexual and maternal behaviour, as well as in the regulation of cardiovascular functions. It has long been known that OT induces natriuresis and causes a fall in mean arterial pressure, both after acute and chronic treatment, but the mechanism was not clear. The discovery of the natriuretic family shed new light on this matter. Atrial natriuretic peptide (ANP), a potent natriuretic and vasorelaxant hormone, originally isolated from rat atria, has been found at other sites, including the brain. Blood volume expansion causes ANP release that is believed to be important in the induction of natriuresis and diuresis, which in turn act to reduce the increase in blood volume. Neurohypophysectomy totally abolishes the ANP response to volume expansion. This indicates that one of the major hypophyseal peptides is responsible for ANP release. The role of ANP in OT-induced natriuresis was evaluated, and we hypothesized that the cardio-renal effects of OT are mediated by the release of ANP from the heart. To support this hypothesis, we have demonstrated the presence and synthesis of OT receptors in all heart compartments and the vasculature. The functionality of these receptors has been established by the ability of OT to induce ANP release from perfused heart or atrial slices. Furthermore, we have shown that the heart and large vessels like the aorta and vena cava are sites of OT synthesis. Therefore, locally produced OT may have important regulatory functions within the heart and vascular beds. Such functions may include slowing down of the heart or the regulation of local vascular tone.
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This article provides a review of the past and current literature on the neurobiology of sexual function. The influence of endocrine, neurotransmitter, and central nervous system influences on male and female sexual function are discussed for sexual desire, arousal, and orgasm or ejaculation stages of sexual responding. Endocrine factors reviewed include the following: androgens, estrogens, progesterone, prolactin, oxytocin, cortisol, and pheromones. Neurotransmitters and neuropeptides discussed include nitric oxide, serotonin, dopamine, epinephrine, norepinephrine, opioids, acetylcholine, histamine, and gamma-aminobutyric acid. Central nervous system influences on sexual function are discussed briefly with reference to brainstem regions, the hypothalamus, and the forebrain.
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The oxytocin receptor (OTR) is differentially expressed in the CNS. Because there are multiple mechanisms by which the OTR can be transcriptionally induced, we hypothesized that differences in OTR expression may be explained by activation of distinct signal transduction pathways and may be critical for the control of anxiety and sex behaviors. To determine the regulation and functional significance of this expression, we infused female rats with modifiers of protein kinases before assaying for behavior and oxytocin receptor binding. In the ventromedial nucleus of the hypothalamus (VMH), estrogen-dependent induction of oxytocin receptors required protein kinase C activation, and oxytocin infused here promoted female sex behavior but had no effect on anxiety. In contrast, dopamine controlled tonic oxytocin receptor expression in the central nucleus of the amygdala (cAmyg) through activation of protein kinase A, and oxytocin infused here was anxiolytic but had no effect on female sex behavior. Therefore, we have identified brain region-specific regulation of the OTR in the VMH and cAmyg. Distinct signal transduction pathways regulating receptor expression and binding in each brain region may mediate in part the ability of oxytocin to exert these differential behavioral effects.
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The neurohypophysial peptide oxytocin (OT) and OT-like hormones facilitate reproduction in all vertebrates at several levels. The major site of OT gene expression is the magnocellular neurons of the hypothalamic paraventricular and supraoptic nuclei. In response to a variety of stimuli such as suckling, parturition, or certain kinds of stress, the processed OT peptide is released from the posterior pituitary into the systemic circulation. Such stimuli also lead to an intranuclear release of OT. Moreover, oxytocinergic neurons display widespread projections throughout the central nervous system. However, OT is also synthesized in peripheral tissues, e.g., uterus, placenta, amnion, corpus luteum, testis, and heart. The OT receptor is a typical class I G protein-coupled receptor that is primarily coupled via G(q) proteins to phospholipase C-beta. The high-affinity receptor state requires both Mg(2+) and cholesterol, which probably function as allosteric modulators. The agonist-binding region of the receptor has been characterized by mutagenesis and molecular modeling and is different from the antagonist binding site. The function and physiological regulation of the OT system is strongly steroid dependent. However, this is, unexpectedly, only partially reflected by the promoter sequences in the OT receptor gene. The classical actions of OT are stimulation of uterine smooth muscle contraction during labor and milk ejection during lactation. While the essential role of OT for the milk let-down reflex has been confirmed in OT-deficient mice, OT's role in parturition is obviously more complex. Before the onset of labor, uterine sensitivity to OT markedly increases concomitant with a strong upregulation of OT receptors in the myometrium and, to a lesser extent, in the decidua where OT stimulates the release of PGF(2 alpha). Experiments with transgenic mice suggest that OT acts as a luteotrophic hormone opposing the luteolytic action of PGF(2 alpha). Thus, to initiate labor, it might be essential to generate sufficient PGF(2 alpha) to overcome the luteotrophic action of OT in late gestation. OT also plays an important role in many other reproduction-related functions, such as control of the estrous cycle length, follicle luteinization in the ovary, and ovarian steroidogenesis. In the male, OT is a potent stimulator of spontaneous erections in rats and is involved in ejaculation. OT receptors have also been identified in other tissues, including the kidney, heart, thymus, pancreas, and adipocytes. For example, in the rat, OT is a cardiovascular hormone acting in concert with atrial natriuretic peptide to induce natriuresis and kaliuresis. The central actions of OT range from the modulation of the neuroendocrine reflexes to the establishment of complex social and bonding behaviors related to the reproduction and care of the offspring. OT exerts potent antistress effects that may facilitate pair bonds. Overall, the regulation by gonadal and adrenal steroids is one of the most remarkable features of the OT system and is, unfortunately, the least understood. One has to conclude that the physiological regulation of the OT system will remain puzzling as long as the molecular mechanisms of genomic and nongenomic actions of steroids have not been clarified.
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Accumulating evidence indicates that gonadal steroids modulate functioning of the hypothalamic-pituitary-adrenal (HPA) axis, which has been closely linked to the pathophysiology of anxiety and depression. However, the effect of the natural menstrual cycle on HPA axis responsivity to stress has not been clearly described. In nine healthy women, metabolic and hormonal responses to treadmill exercise stress during the early follicular phase of the menstrual cycle, when gonadal steroid levels are low, were compared with responses in the midluteal phase of the cycle, when both progesterone and estrogen levels are relatively high. Exercise intensity was gradually increased over 20 min to reach 90% of each subject's maximal oxygen consumption during the final 5 min of exercise. Basal plasma lactate, glucose, ACTH, vasopressin, oxytocin, and cortisol levels were similar in the two cycle phases. However, in response to exercise stress, women in the midluteal phase had enhanced ACTH (P < 0.0001), vasopressin (P < 0.01), and glucose (P < 0.001) secretion. These findings suggest that relatively low levels of gonadal steroids during the early follicular phase of the menstrual cycle provide protection from the impact of stress on the HPA axis.
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Preterm delivery is the largest cause of perinatal mortality and morbidity, yet the treatment of preterm labour has not been demonstrated to improve outcome. The reasons are numerous and complex, but they include a failure to understand the mechanism(s) of preterm labour, the multitude of different causes, the difficulty in diagnosis and the problems of outcome measurement in clinical trials. Recently, an oxytocin antagonist (atosiban) has been introduced into clinical practice in Europe. Although it may be an effective tocolytic, a beneficial effect on perinatal outcome has not been demonstrated. Atosiban has an effect at both oxytocin and vasopressin (V(1a)) receptors, which (assuming efficacy) raises the question as to whether oxytocin or vasopressin V(1a) antagonism is required for tocolysis. This review examines the rationale for tocolysis in preterm labour, the evidence for administration of atosiban and the role for oxytocin, vasopressin and their receptors in the onset of labour. Experimental Physiology (2001) 86.2, 297-302.
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In previous studies, central administration of the oxytocin (OT) antagonist d(CH2)5[Tyr(Me)2, Thr4, Tyr-NH(9)2]OVT (OTA1) blocked receptive and proceptive components of female sexual behavior (FSB) and increased male-directed agonistic behavior when given before progesterone (P) treatment in estradiol-primed female rats but not when given shortly before behavioral testing 4-6 h after P. Because the considerable V(1a) antagonist potency of OTA1 may have contributed to these results, we tested the effects of the far more selective OT antagonist desGly-NH2, d(CH2)5[d-Tyr2, Thr4]OVT (OTA2). In ovariectomized, estradiol benzoate-primed (1 microg x 2 days sc) rats, icv infusion of OTA2 (1 microg) prior to P injection (250 microg sc) significantly suppressed lordosis and hops and darts and trended toward significantly increasing male-directed kicks during testing at 4 and 6 h. Infusion of OTA2 3 h and 40 min after P did not alter behavior at 4 and 6 h after P but significantly decreased lordosis as well as hops and darts and increased male-directed kicks 8-12 h after P. These results provide further evidence that central OT receptor activation shortly after P treatment contributes to the subsequent onset and early expression of FSB and demonstrate, for the first time, that OT receptor activation at later time points also contributes to maintaining FSB. The FSB-stimulating effect of central OT appears to persist for several hours.
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