Prolactin, through peripheral neural pathway, has luteolytic effect in late pregnant rat

VALLCANERAS S; CASAIS M; MOTTA A; ANZULOVICH AC; RASTRILLA AM

Congreso; XLVI Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2010

Prolactin, through peripheral neural pathway, has luteolytic effect in late pregnant rat.  Vallcaneras S,  Casais M, Motta A, Anzulovich AC, Rastrilla AM.  Lab. Biol. Reprod (LABIR)- FQByF -UNSL - San Luis -Chacabuco 917  ssvallca@unsl.edu.ar  Prolactin (PRL) performs dual effect (luteotropic and luteolytic) on the different types of corpora lutea. The aim was to investigate, using the ex vivo celiac ganglion-superior ovarian nerve-ovary (CG-SON-O) system of 21-day pregnant rats, whether PRL via NOS is able to modular the luteal regression. The system was incubated in Krebs Ringer at 37¨C, keeping CG and ovary connected by the SON, in separate compartments. PRL (10-7M) was added in the ganglionic comparment (PRL)g, Controls were not stimulated. Periodic extractions of the ovary incubation liquid were carried out at 30, 60, 120, 180 y 240 min. to subsequent measure of progesterone (P), oestradiol (E2), PGF2alpha by RIA and nitrites by Griess method. At 240 min, the luteal mRNA expression of 3beta-HSD, 20alpha-HSD, aromatase, PGF2alphaR, iNOS, bcl-2 and bax were analysed by RT-PCR. ANOVA 1 followed by Tuckey test with a statistical significance of p <0.05 was used. (PRL)g decreased the release of P within modify the expression of 3beta-HSD and 20alpha-HSD and decreased only the release of E2 at 240 min of incubation within affect the expression of aromatase.   (PRL)g increased the release of nitrites within affect the expression of iNOS and increased the release of PGF2alpha, which receptor showed a tendency to decrease, while that the ratio bcl-2 to bax was decreased. PRL, via the SON, promotes the luteal regression at the end of pregnancy in the rat.