DIFFERENT MODULATION OF STEROIDOGENESIS AND PROSTAGLANDIN PRODUCTION IN FROG OVARY IN-VITRO BY ACE AND ANG-II

Our aim was to study the role of angiotensin-converting enzyme (ACE) a nd angiotensin II (ANG II) on ovarian steroidogenesis and prostaglandi n production of amphibian. Hormonal effects of ACE, ACE inhibitors, sy nthetic bullfrog angiotensin I(ANG I), and [Val(5)]ANG II were compare d on frog ovaries of postreproductive and prereproductive periods. Ver y high ACE activity was found in ovary of water frog (Rana esculenta) compared with other frog tissues, and this activity was inhibited by t he typical ACE inhibitors, captopril and lisinopril. Frog ovary tissue in postreproductive and prereproductive periods was incubated in vitr o in the presence of ACE (2.5 mU/ml), captopril (0.1 mM), lisinopril ( 0.1 mM), [Val(5)]ANG II (1 mu M), and synthetic bullfrog ANG I (1 mu M ). Production of 17 beta-estradiol, progesterone, androgens, and prost aglandins E-2 and F-2 alpha was determined. The data showed a modulati on of 17 beta-estradiol, progesterone, and prostaglandin E-2 productio n by ovary ACE; on the other hand, [Val(5)]ANG II modulated the produc tion of progesterone and prostaglandin F-2 alpha, whereas androgen pro duction was not influenced. The present in vitro studies suggest the e xistence of two pathways independently regulated by ACE and ANG II mod ulating ovarian steroidogenesis and prostaglandin production.