Luteal steroidogenesis and progesterone production in Lagostomus maximus: does prolactin play a central role by regulating the expression of the enzymes 3betaand 20alpha-HSD?

PROIETTO S, CORTASA, SA, CORSO MC, INSERRA PIF, CHARIF S, SCHMIDT AR, DI GIORGIO NP, LUX-LANTOS V, VITULLO AD, DORFMAN VB; HALPERIN J

Concon

Congreso; XXVIII Reunión Anual de la Sociedad Chilena de Reproducción y Desarrollo; 2017

SCHRD

Prolactin(PRL) is a pleiotropic factor that modulates a myriad of processes,many of them directly affecting reproduction. In rodents, the absenceof PRL causes infertility due to a failure of the corpora lutea insynthesizing and secreting the necessary amounts of progesterone (P4)to successfully sustain embryo implantation. Westudied the expression of pituitary PRL, ovarian LH, P4 and PRLreceptors (LHR, PR and PRLR), and of the enzymes 20α-HSD and 3ß-HSDin Lagostomusmaximusthroughout early-, mid- and term-pregnancy (EP, MP and TP), lactation(LCT) and after weaning of the litter (NP). Asexpected to occur in view of a forthcoming offspring, pituitary PRLincreased during pregnancy and, although it decreased afterparturition, mRNA levels in LCT were higher than in NP females.Luteal PRLR reached its maximum at MP and it drastically decreased atTP. LHR expression exhibited the same profile than PRLR. Maximalvalues of both P4 and LH were also recorded at MP. Remarkably,whereas ovarian 3ß-HSD exhibited an expression pattern similar tothat of PRLR/LHR, 20α-HSD behaved in a complete opposite fashion:20α-HSD displayed low expression at EP and MP but it reached itsmaximum at TP, when PRLR/LHR/3ß-HSD were minimal and coincided aswell with the significant drop of circulating P4 which ultimatelytriggered parturition. In conclusion, both PRLR and LHR expressionswould be defining the success of a gestation at term by modulatingthe levels of both 20α-HSD and 3ß-HSD, which ultimately determinethe level of circulating P4