Molecular mechanisms participating in inhibition of GnRH/LH secretion induced by CRH

• Autorzy: Ciechanowska M. , Lapot M. , Paruszewska E. , Brytan M. , Przekop F.
• Języki publikacji: EN

Abstrakty

EN

INTRODUCTION: It is generally accepted that corticotropin-releasing hormone (CRH) is the central mediator of stress-activated changes in the pituitary-adrenal axis because it results in the release of adrenocorticotropic hormone (ACTH) and finally increases the levels of cortisol. In some situations CRH also inhibits the release of GnRH and it has been proposed as a mediator of the anti‑reproductive effects of stress. AIM(S): This study aimed to explain how prolonged activation or inhibition of CRH‑ergic activity affected molecular processes governing GnRH/LH secretion in follicular-phase sheep. METHOD(S): The study included two experimental approaches: first, we investigated the effect of CRH or CRH antagonist (α‑helical CRH 9‑41; CRH‑A) on GnRH and GnRH receptor (GnRHR) biosynthesis in the hypothalamus and on GnRHR in the anterior pituitary gland (AP) using an immunoassay (ELISA). This analysis was supplemented by radioimmunoassay (RIA) method for LH; second, we used Real-time PCR to analyse the influence of CRH and CRH‑A on the levels of kisspeptin (Kiss 1) mRNA in the preoptic area (POA) and ventromedial hypothalamus including arcuate nucleus (VMH/ARC). RESULTS: Our results show that stimulation or inhibition of CRH receptors significantly decreased or increased GnRH biosynthesis in the hypothalamus, respectively, and led to differentresponsesin the expression of GnRHR. CRH increased GnRHR abundance in the POA, but decreased it in the hypothalamus and in the AP. Blockade of CRH receptors had the opposite effect on the level of post‑translational product of GnRHR gene. In addition, administration of CRH decreased plasma LH concentration and Kiss1 mRNA in the POA and VMH/ARC, while CRH-A exerted an opposite action. CONCLUSIONS: The study demonstrates that CRH-ergic neurotransmission is involved in the regulatory pathways of GnRH and GnRHR biosynthesis in the hypothalamic-pituitary unit of follicular-phase sheep conceivably via mechanisms in which Kiss 1 participate. FINANCIAL SUPPORT: This work was supported by grant National Science Center Poland No UMO-2012/05/B/ NZ4/02443.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2017
• Tom: 77
• Numer: Suppl.1
• Opis fizyczny: p.108-109

Twórcy

autor

Ciechanowska M.

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

autor

Lapot M.

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

autor

Paruszewska E.

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

autor

Brytan M.

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

autor

Przekop F.

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