Effects of Follicle Stimulating Hormone and Luteinizing Hormone upon Cyclic AMP and Cyclic GMP Levels in Rat Ovariesin Vitro12

Abstract

In vitro effects of FSH [follicle stimulating hormone] and LH [luteinizing hormone] on cyclic[c]AMP and cGMP levels in rat ovarian tissue were studied. Ovaries from immature rats treated with either pregnant mare''s serum (PMS) or PMS and human chorionic gonadotropin (hCG) were incubated at 37.degree. C for 30 min in defined medium 199 containing aminophylline (0.1 mg/ml). Increasing concentrations of LH (0.4-10.0 .mu.g) when added to the medium containing ovaries with predominantly follicular tissue (PMS-treated) produced progressive increases in cAMP (29-300%) and concomitant decreases in cGMP (41-70%). FSH (4-100 .mu.g) added to the medium produced comparable changes in nucleotide levels: cAMP increased 52-390% and cGMP decreased 45-80%. Ovaries with predominantly luteal tissue (PMS- and hCG-treated) responded differently to the same experimental conditions. LH produced a much greater increase in tissue cAMP levels (109-1280%): FSH produced comparable increases in cAMP as seen with follicular tissue (103-570%). Neither gonadotropin caused any changes in cGMP levels in luteinized ovaries. Rat ovarian cGMP is regulated by gonadotropins and the differences in the direction of nucleotide response to gonadotropins suggest divergent roles for cAMP and cGMP in ovarian function.