Neuromodulatory effect of GnRH from coeliac ganglion on luteal regression in the late pregnant rat

MORALES L; VALLCANERAS S; DELSOUC MB; FILIPPA VP; AGUILERA-MERLO C; FERNANDEZ M; CASAIS M

CELL AND TISSUE RESEARCH

SPRINGER

Lugar: Berlin; Año: 2021 vol. 384/ p. 487 - 498

0302-766X

The GnRH/GnRH receptor system has been found in several extrapituitary tissues although its physiological significance has not yet been well established. Taking into account that the peripheral neural system can act as a modulator of pregnancy corpus luteum, the objective of this study was physiologically to investigate the presence of the GnRH system in Coeliac Ganglion (CG) and to analyse its possible involvement in luteal regression, through the Superior Ovarian Nerve (SON) at the end of pregnancy in the rat. The integrated ex vivo CG-SON-Ovary system of rats on day 21 of pregnancy was used. Cetrorelix (CTX), a GnRH receptor antagonist, was added into the ganglionic compartment while the control systems were untreated. Ganglionic GnRH release was detected under basal conditions. Then, the CTX addition in CG increased it, which would indicate the blockade of receptor. In turn, the addition of CTX in CG caused an increase in the ovarian progesterone release. Furthermore, the luteal cells showed an increase in the expression (mRNA) of Hsd3b1 and a decrease in the expression of Akr1c3 (progesterone synthesis and degradation enzymes, respectively), reduced TUNEL staining according to an increase in the antioxidant defense system activity and low lipid peroxide levels. The ovarian and ganglionic nitric oxide (NO) release increased, while the luteal nitrotyrosine content, measured as nitrosative stress marker, decreased. The present study provides evidence that GnRH from CG may trigger neuronal signals that promote the luteal regression in late pregnancy by affecting the release of NO in the ovary.