Allopregnanolone modifies 3 beta- HSD activity and expresión in hypothalamus and ovary of rats in an estrus cycle dependent manner

GIULIANI F.; VEGA A.; CASAS S.; NANFARO F.; BAZZOCCHINI V.; YUNES R.; CABRERA, R.

Tandil

Congreso; XL Reunión Científica Anual de la de la Sociedad Argentina de Farmacología Experimental.; 2008

SAFE

BV-107. ALLOPREGNANOLONE MODIFIES 3b-HSD ACTIVITY AND EXPRESSION IN HYPOTHALAMUS AND OVARY OF RATS IN AN ESTRUS CYCLE DEPENDENT MANNER Giuliani F, Vega Orozco AS, Casas S, Nanfaro F, Bazocchini V, Yunes R, Cabrera R. LINCE-IMBECU-CONICET. Area de Farmacología, Facultad de Ciencias Medicas, UN de Cuyo., Ciudad Universitaria, (CP 5500) Mendoza, Argentina. E-mail: fgiuliani@fcm.uncu.edu.ar 3-b-hydroxysteroid dehidrogenase (3-b-HSD) converts pregnenolone to progesterone. Previously we demonstrated that Allopregnanolone (Allo) icv inhibits the LH release, ovulation and lutheal apoptosis. The aim was to study if Allo icv modifies enzymatic activity and gene expression of hypothalamic and ovarian 3- b-HSD during proestrous (P) and diestrous (D). Female Holtzman adults rats were injected in third ventricle with Allo 6ìM or vehicle (KRBG) and sacrified 30 min later. 3-b-HSD activity was measured by spectrophotometric method.The gene expression was studied by RT-PCR. The results were analized by T-test, p<0.05 was considered significant. In P, Allo decreased 3-b-HSD activity in hypothalamus (p<0.001) and ovary (p<0.01), but no significant changes were observed in the gene expression. In D, Allo increased the enzimatic activity (p<0.01) and the gene expression (p<0.05) in ovary and hypothalamus respectively. We conclude that Allo modulates the activity and the gene expression of 3-b-HSD in hypothalamus and ovary in an estral cycle dependent manner. Moreover we show that the neurosteroids are important modulators of the molecular mechanisms involved in the reproductive physiology of the female rat.