The influence of dapaminergic system inhibition on kisspeptin and rfamide-related peptide-3 transcripts and gonadotropin releasing-hormone/receptor proteins in anestrous ewes

• Autorzy: Lapot M. , Ciechanowska M. , Kowalczyk M. , Mateusiak K. , Paluch M. , Antkowiak B. , Przekop F.
• Języki publikacji: EN

Abstrakty

EN

BACKGROUND AND AIMS: The aim of this study was to explain how prolonged inhibition of central dopaminergic activity affected the neuroendocrine processes controlling GnRH/gonadotropins secretion in the hypothalamus and in the anterior pituitary gland compartments of sheep during the non-breeding time. In this purpose, we investigated the effects of prolonged, intermittent infusions of small doses of sulpiride (dopaminergic D2 receptors antagonist) on transcript levels of the two central regulators of the hypothalamic-pituitary reproductive system – kiss 1 and RFRP-3. It was also examined the influence of sulpiride on the GnRH and GnRH receptor (GnRHR) biosynthesis in the hypothalamus-pituitary unit. Additionally, these analyses were complemented by the study of plasma LH concentration. METHODS: The levels of kiss 1 and RFRP-3 transcripts and GnRH and GnRHR proteins were analyzed using Real-time PCR technique or an enzyme-linked immunoabsorbent assay (ELISA), respectively. Plasma LH concentration was measured by a doubleantibody radioimmunoassay. RESULTS: Pharmacological blockade of D2 receptors by sulpiride significantly increased kiss 1 mRNA levels in the preoptic area and in the arcuate nucleus/ventromedial hypothalamus and decreased the RFRP-3 mRNA in the paraventricular nucleus. The abolition of dopaminergic neurons activity also resulted in augmentation of the GnRH and GnRHR protein levels in the entire hypothalamus and led to similar changes in the expression of GnRHR in the anterior pituitary gland. The increase of kiss 1 transcription and GnRH biosynthesis has appeared with a concomitant increase of LH secretion. CONCLUSIONS: Similar direction of changes of kiss 1 transcript and GnRH protein levels with LH secretion strongly suggest that the inhibition of D2 receptors has a stimulatory effect on kiss1/ GnRH biosynthesis and consequently on LH release. It is likely, that dopamine inhibits gonadotropin synthesis and release in anestrous period through complex actions of kiss1/RFRP-3 neurons on GnRH cells.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2015
• Tom: 75
• Numer: Supl.
• Opis fizyczny: p.S56

Twórcy

autor

Lapot M.

• Department of Pharmacology and Toxicology, General Karol Kaczkowski Military Institute of Hygiene and Epidemiology, Warsaw, Poland

autor

Ciechanowska M.

• Department of Pharmacology and Toxicology, General Karol Kaczkowski Military Institute of Hygiene and Epidemiology, Warsaw, Poland

autor

Kowalczyk M.

• Jozef Piłsudski University of Physical Education, Warsaw, Poland

autor

Mateusiak K.

• Jozef Piłsudski University of Physical Education, Warsaw, Poland

autor

Paluch M.

• Department of Pharmacology and Toxicology, General Karol Kaczkowski Military Institute of Hygiene and Epidemiology, Warsaw, Poland

autor

Antkowiak B.

• Jozef Piłsudski University of Physical Education, Warsaw, Poland

autor

Przekop F.

• Department of Neuroendocrinology, Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Jabłonna, Poland