Tomasz Misztal

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Neuropeptide Y (NPY) is a putative mediator of many physiological processes in the central nervous system including reproductive functions. In this study we examined the effect of NPY on the GnRH/LH secretory activity in early anoestrous ewes. Crossbreed ewes one week (group 1w, n=7) and six weeks (group 6w, n=7) after the last oestrous cycle were infused(More)
There is no information in the literature regarding the effect of corticotropin-releasing hormone (CRH) on genes encoding gonadotrophin-releasing hormone (GnRH) and the GnRH receptor (GnRHR) in the hypothalamus or on GnRHR gene expression in the pituitary gland in vivo. Thus, the aim of the present study was to investigate, in follicular phase ewes, the(More)
Data exists showing that seasonal changes in the innervations of GnRH cells in the hypothalamus and functions of some neural systems affecting GnRH neurons are associated with GnRH release in ewes. Consequently, we put the question as to how the expression of GnRH gene and GnRH-R gene in the hypothalamus and GnRH-R gene in the anterior pituitary gland is(More)
Orexin A may play a special role in animals' sensitivity to the day length changes such as sheep. The localization of mRNA for prepro-orexin in the ovine hypothalamus was found to correspond to the pattern described in rodents. The results of that research also showed that the expression of the orexin gene depends on the length of a day and is higher during(More)
Secretion of all the pituitary hormones undergoes marked circadian and seasonal changes. The rhythmicity of these changes is controlled by the circadian pacemaker system and the pineal gland transmitting daylength information to the neuroendocrine axis via the secretion of melatonin. This article presents data on the effects of the short-term melatonin(More)
The RT-PCR (reverse transcription polymerase chain reaction) technique was used to analyze GnRH mRNA and GnRH-R mRNA in the preoptic area, anterior and ventromedial hypothalamus, and GnRH-R mRNA in the stalk/median eminence and anterior pituitary gland of follicular ewes subjected to short (3 h during one day) or prolonged (5 h daily during four consecutive(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)
The present study tested a hypothesis, whether plant-derived genistein influences the secretion of growth hormone (GH) in ewes, acting directly within the central nervous system (CNS). Starting six weeks after ovariectomy, ewes were infused intracerebroventricularly with genistein (n = 5) or 17beta-estradiol (n = 5), both in a total dose of 40 microg/400(More)
We examined by Real-time PCR how prolonged inhibition of dopaminergic D-2 receptors (DA-2) in the hypothalamus of anestrous ewes by infusion of sulpiride into the third cerebral ventricle affected GnRH and GnRH-R gene expression in discrete parts of this structure and GnRH-R gene expression in the anterior pituitary. Blockaded DA-2 receptors significantly(More)
The effect of prolonged, intermittent infusion of GABA(A) receptor agonist (muscimol) or GABA(A) receptor antagonist (bicuculline) into the third cerebral ventricle on the expression of GnRH gene and GnRH-R gene in the hypothalamus and GnRH-R gene in the anterior pituitary gland was examined in follicular-phase ewes by real-time PCR. The activation or(More)