The key action of estradiol and progesterone enables GnRH delivery during gestation in the South American plains vizcacha, Lagostomus maximus

Publication date: Available online 15 February 2020Source: The Journal of Steroid Biochemistry and Molecular BiologyAuthor(s): Pablo I.F. Inserra, Santiago E. Charif, Victoria Fidel, Mariela Giacchino, Alejandro R. Schmidt, Federico M. Villarreal, Sofía Proietto, Santiago A. Cortasa, María C. Corso, María C. Gariboldi, Noelia P. Leopardo, Nicolás A. Fraunhoffer, Noelia P. Di Giorgio, Victoria A. Lux-Lantos, Julia Halperin, Alfredo D. Vitullo, Verónica B. DorfmanAbstractThe South American plains vizcacha, Lagostomus maximus, is the only mammal described so far that shows expression of estrogen receptors (ERs) and progesterone receptors (PRs) in gonadotropin-releasing hormone (GnRH) neurons. This animal therefore constitutes an exceptional model for the study of the effect of steroid hormones on the modulation of the hypothalamic-pituitary-ovarian (HPO) axis. By using both in vivo and ex vivo approaches, we have found that pharmacological doses of progesterone (P4) and estradiol (E2) produced an inhibition in the expression of hypothalamic GnRH, while physiological doses produced a differential effect on the pulsatile release frequency or genomic expression of GnRH. Our ex vivo experiment indicates that a short-term effect of E2 modulates the frequency of GnRH release pattern that would be associated with membrane ERs. On the other hand, our in vivo approach suggests that a long-term effect of E2, acting through the classical nuclear ERs-PRs pathway, would produce the modi...
Source: The Journal of Steroid Biochemistry and Molecular Biology - Category: Biochemistry Source Type: research