ALLOPREGNANOLONE (ALLO) MODULATES THE ENZYMATIC

CASAS S.; GIULIANI F.; YUNES R.; CABRERA R.; LACONI M.

Mendoza,

Congreso; XXVI Reunión Científica Anual de la Sociedad de Biología de Cuyo. I Reunión Científica Anual de la Dirección de Investigación, Ciencia y Técnica dependiente del Ministerio de Salud Gobierno de Mendoza.; 2008

Sociedad de Biología de Cuyo y Ministerio de Salud. Gobierno de Mendoza

The enzyme 20 a-hydroxysteroid dehydrogenase (20a-HSD) catabolizes progesterone into a biologically inactive steroid, 20a- dihydroprogesterone (20a-HP). In the corpora lutea of rats, 20a- HSD is involved in functional luteolysis. In the present study, we investigated the modulatory activity of Allopregnanolone (Allo) on the 20a-HSD activity in estrous cycle rats. We used adult female Spague-Dawley rats. After 7 days of intracerebroventricular (icv) surgeon, samples of vaginal smears were taken daily from 09.00 to 10.00. Rats at estrous (E) and diestous 1 (D1) were selected and inyected icv with Allo 0.6 mM or KRBG as control. The injection of Allo caused a significant decrease on 20a-HSD activity on HMB (p<0.05) in rats at estrous. While, Allo did not modify the enzymatic activity in the ovary of the same animals. On the other hand, on D1, Allo could not modify the 20a-HSD activity neither in HMB nor in ovary. In our previous reports we found that Allo inhibit the luteal regresion (3b-HSD activity and histological evidence). The current results on 20a-HSD activity in ovary and in HMB confirm our previous finding suggesting that the neurosteroid Allo could modify the 20a-HSD activity on estrous cycle dependent manner. Finally, these results confirm the potencial role of Allo as luteal regresion inhibitor in female rats.