Lubos Molcan

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Verified

Lubos verified their affiliation via an institutional email.

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• Ph.D.
• Professor (Associate) at Comenius University Bratislava

Effects of phase delay shifts (PDS) of light in combination with moderately increased salt intake (SL) (2%) or time restriction of food (FR) during the light-time (passive phase) on heart rate (HR), blood pressure (BP) and locomotor activity (LA) in radiotelemetry-measured rats were evaluated. PDS decreased amplitude and spectral power of circadian...

Disturbed circadian activity of the sympathetic system may be involved in negative consequences of chronodisruption on the cardiovascular system. We studied daily changes in pressure response to adrenergic stimulation in rats exposed to repeated phase advance shifts (PAS) of light/dark (LD) regimen. Blood pressure (BP), heart rate (HR) and locomoto...

Cardiovascular parameters, such as blood pressure and heart rate, exhibit both circadian and ultradian rhythms which are important for the adequate functioning of the system. For a better understanding of possible negative effects of chronodisruption on the cardiovascular system we studied circadian and ultradian rhythms of blood pressure and heart...

Melatonin is involved in blood pressure modulation in rats and humans. Some of the effects of melatonin are presumably mediated via two G-protein-coupled receptors (MT(1) and MT(2)), but the distribution of MT(1) and MT(2) in the cardiovascular system remains to be explored comprehensively. We investigated the expression of both the receptors in th...

Artificial light at night (ALAN) disrupts 24-h variability of blood pressure, but the molecular mechanisms underlying these effects are unknown. Therefore, we analysed the daily variability of pulse pressure, the maximum value of acceleration rate of aortic pressure (dP/dt(max)) measured by telemetry and protein expression in the thoracic aorta of...

Artificial light at night (ALAN) affects most of the population. Through the retinohypothalamic tract, ALAN modulates the activity of the central circadian oscillator and, consequently, various physiological systems, including the cardiovascular one. We summarised the current knowledge about the effects of ALAN on the cardiovascular system in diurn...

Aldosterone regulates blood pressure (BP) through water and sodium balance. In our study, we studied if continuous treatment with a mineralocorticoid receptor antagonist, spironolactone (30 mg/kg/day) for 20 days can: 1) attenuate hypertension development and restore inverted 24-h BP rhythm in hypertensive transgenic (mRen-2)27 rats (TGR) measured...

The hypotensive effects of melatonin are based on a negative correlation between melatonin levels and blood pressure in humans. However, there is a positive correlation in nocturnal animals that are often used as experimental models in cardiovascular research, and the hypotensive effects and mechanism of melatonin action are often investigated in r...

s Aim: To examine whether the serum melatonin levels in ICU patients are affected by light exposure in the "light" and "dark" parts of the ICU. Method: We measured serum melatonin levels of 10 ICU patients having their bed positioned in the "light part" (artificial and natural light) and "dark part" (only artificial light) of the ICU at two differe...

Prenatal hypoxia during the prenatal period can interfere with the developmental trajectory and lead to developing hypertension in adulthood. Prenatal hypoxia is often associated with intrauterine growth restriction that interferes with metabolism and can lead to multilevel changes. Therefore, we analysed the effects of prenatal hypoxia predominant...

Cardiovascular (CV) health is often expressed by changes in heart rate and blood pressure, the physiological record of which may be affected by moving, anaesthesia, handling, time of day and many other factors in rodents. Telemetry measurement minimises these modulations and enables more accurate physiological recording of heart rate and blood pres...

Melatonin is released by the pineal gland and can modulate cardiovascular system function via the G protein-coupled melatonin receptors MT1 and MT2. Most vessels are surrounded by perivascular adipose tissue (PVAT), which affects their contractility. The aim of our study was to evaluate mRNA and protein expression of MT1 and MT2 in the mesenteric a...

New findings: What is the central question of this study? Artificial light at night decreases blood pressure and heart rate in rats. Are mentioned changes in heart rate accompanied by changes in protein expression in the heart's left ventricle? What is the main finding and its importance? For the first time, we reported that five weeks of artifici...

Prenatal hypoxia (PH) has negative consequences on the cardiovascular system in adulthood and can affect the responses to additional insults later in life. We explored the effects of PH imposed during embryonic day 20 (10.5% O 2 for 12 h) on circadian rhythms of systolic blood pressure (BP) and heart rate (HR) in mature male rat offspring measured...

Physiological processes oscillate in time. Circadian oscillations, over approximately 24-h, are very important and among the most studied. To evaluate the presence and significance of 24-h oscillations, physiological time distributed data (TDD) are often set to a cosinor model using a wide range of irregularly updated native apps. If users are fami...

Circadian rhythms are an inherent property of physiological processes and can be disturbed by irregular environmental cycles, including artificial light at night (ALAN). Circadian disruption may contribute to many pathologies, such as hypertension, obesity, and type 2 diabetes, but the underlying mechanisms are not understood. Our study investigate...

Aims: Cardiovascular parameters exhibit significant 24-h variability, which is coordinated by the suprachiasmatic nucleus (SCN), and light/dark cycles control SCN activity. We aimed to study the effects of light at night (ALAN; 1-2 lx) on cardiovascular system control in normotensive rats. Main methods: Heart rate (HR) and blood pressure (BP) we...

This study investigated the effect of lisinopril (angiotensin-converting enzyme inhibi-tor) on potential behavioural alterations in spontaneously hypertensive rats (SHR). Three groups of 15-17-week-old rats were investigated for 2 weeks: Wistar control group, SHR group and SHR+lisinopril group. Systolic blood pressure (SBP) was normal in Wistar rat...

Background Intensive care unit (ICU) patients experience two affronts to normal 24‐h rhythms: largely internal events such as medication and external factors such as light, noise and nursing interventions. Aims and objectives We investigated the impact of light variance within an ICU on 24‐h rhythmicity of three key physiological parameters: heart...

Physiological variables such as heart rate (HR) and blood pressure (BP) exhibit long-term circadian rhythms, which can be disturbed by shift work. On the other hand, short-term oscillations in HR and BP have a high prognostic value. Therefore, we aimed to determine if the short-term variability, complexity and entropy of HR and BP would be affected...

Disturbances in regular circadian oscillations can have negative effects on cardiovascular function, but epidemiological data are inconclusive and new data from animal experiments elucidating critical biological mechanisms are needed. To evaluate the consequences of chronic phase shifts of the light/dark (LD) cycle on hormonal and cardiovascular rh...

Decreased oxygenation during pregnancy and early periods of ontogeny can affect normal body development and result in diseases in adulthood. The aim of this study was to use the model of prenatal intermittent hypoxia (PIH) and evaluate the effects of short-term hypoxia at the end of gestation on blood pressure (BP) control in adulthood. Wistar rats...

Under physiological conditions the mammalian circadian system is synchronized to a cyclic environment. The central oscillator in the suprachiasmatic nuclei (SCN) responds predominantly to an external light (L) dark (D) cycle. Peripheral oscillators are more efficiently synchronized by metabolic cues. When the circadian system is exposed to opposing...

Light, especially its blue component, is the main synchronizer of circadian rhythms. We investigated effects of suppressed blue band of the spectrum on melatonin production and sleep efficiency in 18 young volunteers. During control days, participants lived in their home environment, and next five days in a room lit only by daylight with windows eq...

Renin-angiotensin-aldosterone system (RAAS) has an essential role in the homeostatic control of arterial blood pressure (BP), in tissue perfusion and control of extracellular fluid volume. Some pathological conditions such as preeclampsia or gestational diabetes mellitus may lead to increased activity of certain pathways the RAAS during pregnancy a...

A direct relationship exists between salt consumption and hypertension. Increased sodium intake does not automatically lead to a rise in blood pressure (BP) because of marked intra-individual variability in salt sensitivity. Wistar rats are a salt-resistant strain and increased salt intake in adults does not induce hypertension. Mechanisms regulati...

Intermittent prenatal exposure to hypoxia is associated with postnatal alteration in cardiac and endothelial functions. Hyperoxic exposure has significant effects on the cardiovascular system including bradycardia, vasoconstriction and endothelial dysfunction. The impact of intermittent prenatal hypoxia on cardiac rhythm control during mild hyperox...

Evaluation of physiological traits in freely moving animals represents an innovative approach allowing physiological studies in undisturbed animals without interference with handling and stress. This approach is important in behavioural sciences and research on physiological basis of cardiovascular diseases. Recently, there is only one such system...