Bülent Gündüz

Çanakkale Onsekiz Mart Üniversitesi | ÇOMÜ · Department of Biology

The goal of this study was to determine when leptin was most effective as a hormone and to clarify the role of leptin in sexual development in Japanese quails (Coturnix coturnix japonica). In the initial study, we compared the effects of long and short photoperiods on the daily plasma leptin levels of adult males. Leptin levels were assessed in blo...

The complex neuronal and hormonal interaction between the brain and gonads controls the neuroendocrine reproductive axis. GnRH, GnIH, and kisspeptin are important neuropeptides in this relationship. Although seasonal variations of these neuropeptides have been demonstrated in photoperiodic animals, there is no clear evidence in their daily rhythms....

AIM: Lavandula genus (Lamiaceae) is represented by 39 species in Türkiye. L. angustifolia has been used as food and alternative medicine throughout history in Anatolia. The effects of this plant on the reproductive physiology of male Syrian hamsters (Mesocricetus auratus) were determined in groups that were injected with different doses of lavender...

Hypericum perforatum L. (St. John's Wort) is a perennial herb known by different local names and widely known for its therapeutic effects. In the long photoperiod, the food consumption of female Syrian hamster (Mesocricetus auratus), the changes in the blood leptin hormone, which has an important role in body weight change and energy metabolism, we...

A pregnant hamster's exposure to changes in environmental factors, such as light, temperature and nutrition, may influence behavioural and physiological changes in offspring. In this study, dietary methyl donor supplementation was employed to examine the role of maternal diet on appetite, body weight, serum leptin levels and locomotor activity in m...

Amaç: Sarı Kantaron (Hypericum perforatum L.) terapötik etkileri ile yaygın olarak bilinen çok yıllık bir bitki türüdür. Bu çalışmanın amacı yetişkin erkek Suriye hamsterlerine (Mesocricetus auratus) farklı dozlarda uygulanan sarı kantaron ekstraktının lokomotor aktivite üzerine etkisinin incelenmesidir.

Immune responses play a key role in the survival of all living things. Intake of inorganic materials is of critical importance in living organisms because of their participation in metabolism and some component of cells. Iron (Fe), magnesium (Mg) and selenium (Se) were selected for this study because of their participation in critical constituents...

Helichrysum arenarium (L.) (Asterales:Asteraceae) Moench is a therapeutic plant which contains etheric oil, flavones and flavon glycosides, sterins, bitter substances and tannins having various coumarins. This plant is thought to have important characteristics such as diuretic effect, dropping stones and sand from the kidney, regulating digestive d...

Dimethyl sulfoxide (DMSO) is a water-miscible solvent with broad applications in cell biology. It functions as a cryoprotective agent in various cells and tissues since it allows long term storage at subzero temperatures. It is also known to act as a stimulant of cellular differentiation and as a free radical scavenger.

The leaves and flowers of common sage (Salvia officinalis L) are evaluated economicall and the oil obtained is also used in the treatment of throat infections and oral wounds due to its antiseptic and antibiotic effects. In addition, there are studies indicating that it treats skin diseases with its antifungal effect, supports the excretion of toxi...

You can find an Article from link: https://link.springer.com/article/10.1007/s42690-021-00432-8 ************************************************************************** Helichrysum arenarium is an therapeutic plant. It is known to contain an etheric oil, flavones and flavon glycosides, sterins, bitter substances and tannins having various coumari...

Dalmatian Sage (Salvia officinalis L.), belongs to Lamiaceae family, is one of the most appreciated herbal plant for richness of the essential oil content and its numerous biologically active compounds. It is used for it's analgesic, memory enhancing, neuroprotective, anticonvulsant, anti-addictive, sedative, anxiolytic, and skeletal muscle relaxan...

The olive tree (Olive europaea) leaf contains bioactive compounds such as phenolic acids, phenolic alchols, flavonoids, secoiridoids and triterpens. The greater wax moth Galleria mellonella is effective model organism which is mostly used for human pathogens immune research. Insect immune system are divided into two types as a humoral and cellular...

St. john's wort (Hypericum perforatum) is well known therapeutic plant. It is a kind of plant that grows naturally in many parts of the world. In addition to being used as a medicine additive, it is also used as making tea by dried form. Recently, it is widely used as a component of sedative drugs in the treatment of depression and also in the trea...

We have shown that circadian changes in leptin concentrations are inversely linked to circulating melatonin levels in the Syrian hamster. The present study aimed to assess the effects of subcutaneous melatonin implants under different photoperiodic conditions: did the implants affect serum leptin levels, body weight, food consumption, and/or testic...

The suprachiasmatic nucleus (SCN) generates and controls the circadian rhythms in mammals including the rhythm of locomotor activity. Leptin is a hormone secreted by adipose tissue that informs the brain about the fat stores. SCN neurons express leptin receptors. Here we investigated the effects of 3 different leptin administrations on the locomoto...

We studied the effects of melatonin and leptin hormones on ovarian follicular development in intact and pinealectomized female Syrian hamsters. We first monitored the oestrous cycle of the hamsters by the vaginal smear samples throughout a ten day period to start the injections simultaneously in all groups and performed saline, melatonin and leptin...

To determine the effects of pinealectomy on endometrial explants in rats and evaluate the activity of superoxide dismutase (SOD) and catalase (CAT) and the levels of malondialdehyde (MDA) in the rat endometriosis model. Rats with experimentally induced endometriosis were randomly divided into three groups after second-look laparotomies. Group 1 (pi...

The jet-lag syndrome and the shift-work malaise take place by rapid changes in photoperiod and disturb people's life frequently. In the present study; we wanted to simulate these conditions. Control, pinealectomized and melatonin including silastic tube implanted Mongolian gerbils were respectively exposed into long (14L:10D), short (8L:16D),...

Spinal cord injury influences many hormones that are known to be involved in the modulation of neurotrophic, neurogenic, and neuroprotective events. Recent studies showed that leptin could be neuroprotective, enhancing neuronal survival in vitro and in vivo. The objective of this study was to evaluate the pattern of the serum leptin levels in rats...

To evaluate the serum melatonin levels in acute period of the spinal cord injury (SCI) caused by trauma in the rats. Traumatic SCI induces many types of physiological and pathological damage, including hormonal level variations. Forty male Sprague-Dawley rats were divided randomly into four groups. In the control group, neither laminectomy nor SCI...

Cortisol has neuroprotective effects. We monitored the serum cortisol levels after cervical and thoracic spinal cord injury (SCI) in four groups of rats. Forty male Sprague-Dawley rats were randomized to four groups. The control group received neither laminectomy nor SCI. The sham group received laminectomy without SCI. The cervical spinal trauma g...

Throughout history folk medicine has served as an alternative or complimentary method of treating disorders like intestinal colic. Mistletoe is a common name for many species of semi-parasitic plants that grow on trees throughout the world, and has been used widely to treat intestinal colic. We conducted a study to evaluate the effect of freeze-dri...

Antitumor drugs may have some significant nervous system side-effects such as disrupted sleep, eating and drinking patterns. European Mistletoe has been investigated for many decades for its potential use against cancer. To test the hypothesis that the non-antineoplastic effects of mistletoe might be mediated by the actions on the circadian timing...

The effects of pinealectomy and leptin hormone on proliferative and apoptotic processes in the epithelia of testicular seminiferous tubules of Syrian hamsters have been investigated. Proliferative and apoptotic processes were assessed semi-quantitatively by proliferating cell nuclear antigen (PCNA) and caspase-3 immune stainings. Animals used in th...

We investigated whether photoperiodic information is transferred from mother to young and whether the pineal gland and its hormone, melatonin, are involved in this transfer in Mongolian gerbils. Adult female gerbils were paired with males and housed in photoperiods of 12L:12D or 8L:16D. Three groups of pregnant gerbils in each photoperiod were prep...

The suprachiasmatic nuclei (SCN) generate the circadian rhythm of many hormones. The hormone leptin is a metabolic signal that informs the brain about fat and energy stores of the body. We investigated whether the rhythm of leptin hormone release in Syrian hamsters is directly controlled by the SCN. Three experiments were performed: in the first, h...

The circadian rhythm of the locomotor activity is regulated by at least 2 external pacemakers, environmental photoperiod and food availability. In the present study, the effects of short-term (2 weeks) food restriction on locomotor activity rhythm in adult male and female Mongolian gerbils were investigated. Animals were fed ad libitum with no rest...

Reproductive activity of Mongolian gerbils is regulated by photoperiod nevertheless body weight regulation is controlled without ambient photoperiod. Food intake is a major factor affecting rodent reproductive efficiency. Leptin is a hormone secreted by adipose tissue and modulates food intake, energy expenditure and body fat stores. In this study...

We tested in Siberian hamsters the nature of the maternal signal that relays photoperiodic information to the developing fetuses. As previous investigations have identified maternal hormonal and circadian components in this process, the specific goal of this presentation is to determine quality of the signal that connotes daylength when it is impar...

Photoperiod is an important environmental cue in the regulation of reproductive activity in Mongolian gerbils. Photoperiodic information is ultimately transduced into a hormonal signal by the pineal gland. We examined the effect of constantrelease melatonin capsules on the testicular size and body weights of male Mongolian gerbils exposed to a long...

Melatonin is produced and secreted by the pineal gland in a rhythmic manner; circulating levels are high at night and low in the day. Leptin is a hormone secreted by adipocytes as a product of the obese gene and plays an important role in regulating body energy homeostasis and reproductive function in rodents and humans. The present study was condu...

The role of photoperiod in adult testicular maintenance and body weight and juvenile development was assessed in male Mongolian gerbils (Meriones unguiculatus). Gerbils were raised on a 14L (14 hr of light) photoperiod. In the first study, adult gerbils with functional testes were transferred to thirteen different photoperiods (0L, 2L, 4L, 6L, 8L,...

We examined the effects of the absence of the pineal gland on testicular maintenance and regression in adult male Mongolian gerbils. Pineal-ectomized and control gerbils were maintained in different photoperiods (0 L, 8 L, 14 L, or 24 L), and body weights and testicular maintenances were investigated. Testes sizes and body weights were measured eve...

The pineal hormone melatonin is known to play an important role in mediating photoperiodic messages to the reproductive system in seasonal breeding animals. Our goal was to test, in a single experimental paradigm, two hypotheses that have been forwarded to describe how the circadian rhythm of pineal melatonin transmits photoperiodic information to...

In a previous paper we demonstrated that properly timed 1-hr infusions of 50 ng melatonin effectively suppressed testicular development in juvenile Siberian hamsters. Only melatonin infused between 20:00 and 21:00 hr was effective in animals exposed to 16L (lights off 20:00 hr). In this paper we further investigate the importance of the coincidence...

We examined the effects of daily melatonin (Mel) infusions in pinealectomized prepubertal male Siberian hamsters in three different conditions. In one study we investigated the body weight maturation response to one hour daily infusions of 10 ng, 25 ng, or 50 ng of Mel in pinealectomized hamsters. Animals received, at day 15 of life, programmed sub...

Gündüz B, Stetson M.H. The impact of photoperiods and melatonin on gonadal development in juvenile Turkish hamsters (Mesocricetus brandti). J. Pineal Res. 1998; 25:193–200. © Munksgaard, Copenhagen The reproductive response of both intact adult and juvenile Turkish hamsters has been thoroughly studied and shown to be similar, unlike the golden hams...

Thesis (Ph. D.)--University of Delaware, 1998. Principal faculty adviser: Milton H. Stetson, Dept. of Biology. Includes bibliographical references (leaves 168-181). Microfilm. s