Prolactin from coeliac ganglion does not affect the luteal regression in lactating rats

VALLCANERAS S; CASAIS M; DE LA VEGA M; MOTTA A; RASTRILLA AM

Congreso; Sociedad de Biología de Cuyo XXIX Reunión Científica Anual; 2011

PROLACTIN FROM COELIAC GANGLION DOES NOT AFFECT THE LUTEAL REGRESSION IN LACTATING RATS Vallcaneras S, Casais M, de la Vega M, Motta A, Rastrilla AM Lab Biol Reprod (LABIR) - FQByF-UNSL - San Luis, Chacabuco 917. (ssvallca@unsl.edu.ar)   We have shown that prolactin (PRL), through neural pathway, promotes regression of the corpus luteum (CL) at the end of pregnancy in the rat. In the lactation, serum levels of the hormone are high and its neural effect on the CL of pregnancy, that is still present in the postpartum period, is unknown. The aim of this study was to investigate the effect of PRL in the celiac ganglion (GC), through superior ovarian nerve (NOS) on luteal regression on day 4 of lactating rats. The system ex vivo GC-NOS-ovary was used. The system was incubated in Krebs Ringer buffer at 37 °C, keeping the GC and the ovary connected by NOS, in separate compartments. PRL was added (10-7M) into the ganglion compartment. Controls were not stimulated. Periodic extractions of the ovary incubation liquid were taken at different times along 240 min. to measure of progesterone and prostaglandin F2á (PGF2á) by RIA and nitrites by the Griess method. At 240 min, the luteal mRNA expression of 3â-HSD and 20á-HSD, PGF2á receptor, ON synthase inducible (iNOS) and bcl-2 and bax (antiapoptotic and proapoptotic factor) were analysed by RT-PCR. ANOVA I followed by Tuckey test with a statistical significance of p <0.05 was used. The addition of PRL in the ganglion compartment did not modify the studied parameters respect to the control group. This leads us to conclude that the neural pathway acts as a fine modulator, thus PRL from GC does not manifest effect because of its high levels endogenous.