Estradiol promotes luteal regresión in late pregnant rats

VALLCANERAS S,; CASAIS M, ; CAMPO VERDE ARBOCCO F; HAP¨®N B; RASTRILLA AM

Congreso; Sociedad de Biología de Cuyo XXVIII Reunión Científica Anual; 2010

ESTRADIOL PROMOTES LUTEAL REGRESSION IN LATE PREGNANT THE RATS Vallcaneras S,  Casais M, Campo Verde Arbocco F,   Hapón B, Rastrilla AM Laboratorio de Biolog¨ªa de la Reproducci¨®n-FQByF-UNSL Chacabuco 917   Estradiol (E2) added to the ganglion compartment of the ex vivo Celiac Ganglion-Superior Ovarian Nerve-Ovary (CG-SON-Ovary) system of 21 day pregnant rats caused a decline in ovarian release of progesterone (P). The objective was to investigate whether E2, via the SON, modifies the expression of 3beta-hydroxysteroid dehydrogenase (3beta-HSD) and 20alpha-HSD (synthesis and degradation P enzymes, respectively), Bcl-2 and Bax (apoptosis regulators) and to analyse whether E2 has the same effect when it is added directly in ovary. E2 10-6M, 10-8M and 10-9M were added to ganglion compartment of the CG-SON-Ovary and to medium of ovarian incubation of 21 day pregnant rats. Controls were not stimulated. Release of P was measured by RIA, luteal mRNA expression of 3beta-HSD, 20alpha-HSD, Bcl-2 and Bax were assessed by RT-PCR. ANOVA 1 followed by Tuckey test with a statistical significance of p <0.05 was used. When E2 was added in the ganglion compartment, the expression of 3beta-HSD showed a tendency to decrease, while that the expression of 20alpha-HSD was not affected, even though P diminished. Besides, the regulators of apoptosis were not affected. The addition of E2 in ovarian compartment decreased the release of ovarian P, decreased significantly the expression of 3beta-HSD and reduced the ratio of Bcl-2 to Bax. The anti-esteroidogenic effect is more evident when E2 is directly impacting the ovary rather than the CG.