Tomasz Misztal

Learn More
The relations between the circadian rhythms of melatonin and prolactin, and the effect of melatonin infused into the third ventricle or the mediobasal hypothalamus (MBH) on prolactin secretion and dopamine (DA) release were studied in anestrous ewes under increasing daylength conditions. The decreased amplitude and duration of nocturnal melatonin secretion(More)
Recent studies have demonstrated photoperiodic changes in leptin sensitivity of seasonal mammals. Herein, we examined the interaction of season (long days (LD) versus short days (SD)) and recombinant ovine leptin (roleptin) on secretion of melatonin and prolactin (PRL) and on mRNA expression of suppressor of cytokine signaling-3 (SOCS-3) in the medial basal(More)
Salsolinol, a dopamine-related compound and prolactin-producing cells were found in the ovine hypothalamus. This study was designed to test the hypothesis that salsolinol, acting from the CNS level, is able to stimulate pituitary prolactin release as well as prolactin mRNA expression in the anterior pituitary cells (AP) and in the mediobasal hypothalamus(More)
The objective of the study was to assess the effects of substitution milk and egg for soya products in breeding diets for rats, with concomitant decrease of the dietary protein level and supplementation with amino acids. Soya-containing (S) and two soya-free (NS and NSA) diets were evaluated as protein and energy sources, and their effects on reproductive(More)
The aim of this study was to determine the maturational activity of gonadotroph cells, the site of synthesis, storage and release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in Polish Merino female sheep born after the summer solstice. The actual time of puberty of these lambs was delayed until the following breeding season, when they(More)
Through binding with estrogen receptors, phytoestrogens, plant-derived estrogen-like compounds, affect numerous reproductive functions. It is not known whether these compounds are capable of evoking effective changes in luteinizing hormone (LH) and prolactin (PRL) secretion in ewes by acting directly within the central nervous system (CNS). The hypothesis(More)
This study was designed to determine the effect of a potent subcutaneously injected acetylcholinesterase inhibitor, rivastigmine (6mg/animal), on the gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH) release during inflammation induced by an intravenous lipopolysaccharide (LPS) (400ng/kg) injection in ewes during the follicular phase of the(More)
The adaptation of the physiology of an animal to changing conditions of light and food availability is evident at the behavioral and hormonal levels. Melatonin, leptin, ghrelin, and orexin, which exhibit rhythmic secretion profiles under ad libitum feeding conditions, are sensitive to changes in daylength, forming a tight web of interrelationships in the(More)
Suppressors of cytokine signalling (SOCS) negatively regulate cytokine-induced signalling pathways and may be involved in leptin and prolactin (PRL) interactions. Herein, we examined the effect of PRL on SOCS-3 mRNA expression in pituitary explants and investigated whether leptin could modify the expression of SOCS-3 mRNA in pituitary explants. In the first(More)
Searching for the role of prolactin (PRL) in controlling gonadotropic axis activity in sheep, we studied the effects of prolonged, intracerebroventricular (i.c.v.) PRL infusion on luteinizing hormone (LH) secretion and catecholaminergic activity in the hypothalamic infundibular nuclei/median eminence (IN/ME) in sexually active ewes during the periovulatory(More)