PROLACTIN, THROUGH PERIPHERAL NEURAL PATHWAY, HAS LUTEOLYTIC EFFECT IN LATE PREGNANT RATS

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

Puerto Madryn

Congreso; 46th. Annual meeting SAIB; 2010

SAIB

Prolactin (PRL) performs dual effects (luteotropic and luteolytic)on the different types of corpora lutea. We investigate, using the exvivo celiac ganglion-superior ovarian nerve-ovary (CG-SON-O)system of 21-day pregnant rats, whether PRL via NOS is able tomodulate luteal regression. The system was incubated in KrebsRinger at 37ºC, keeping the CG and the ovary connected by theSON, in separate compartments. PRL (10-7M) was added in theganglionic compartment (PRL)g, Controls were not stimulated.Periodic extractions of the ovary incubation liquid were carried outat 30, 60, 120, 180 y 240 min to subsequently measureprogesterone (P), oestradiol (E2), PGF2á concentrations by RIAand nitrites by the Griess method. At 240 min, the luteal mRNAexpression of 3â-HSD, 20á-HSD, aromatase, PGF2áR, iNOS, bcl-2 and bax were analysed by RT-PCR. ANOVA 1 followed by theTuckey test with a statistical significance of p <0.05 was used.(PRL)g decreased the release of P without affecting the expressionof 3â-HSD and 20á-HSD and decreased only the release of E2 at240 min of incubation, without affecting the expression ofaromatase. (PRL)g increased the release of nitrites withoutaffecting the expression of iNOS and increased the release ofPGF2á, whose receptor showed a tendency to decrease, while theratio bcl-2:bax decreased. PRL, via the SON, promotes lutealregression at the end of pregnancy in rats.