title: Stimulation and inhibition of rat oocyte meiosis by forskolin.
abstract: The adenylate cyclase activator forskolin was used to study the role of cAMP for oocyte meiosis and follicular steroid secretion. Follicular and cumulus cAMP production was stimulated dose-dependently by forskolin, as was the follicular secretion of progesterone, testosterone and estradiol. Forskolin induced meiosis in follicle-enclosed oocytes with a maximal effect at 1 microM, with lower and higher concentrations being less effective. The spontaneous resumption of meiosis in isolated cumulus-enclosed oocytes was dose-dependently retarded by forskolin. Meiosis of cumulus-free oocytes was also retarded but only slightly. These data support the earlier hypothesis that a limited increase in follicular cAMP levels triggers meiosis, whereas sustained levels of cAMP in the oocyte itself prevent meiosis.
mesh_terms: D000818:Animals; D005576:Colforsin; D046508:Culture Techniques; D000242:Cyclic AMP / Q000378:metabolism; D004224:Diterpenes / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D008540:Meiosis / Q000187:drug effects*; D009865:Oocytes / Q000187:drug effects*; D006080:Ovarian Follicle / Q000187:drug effects; D051381:Rats
chemical_list: D004224:Diterpenes; D005576:Colforsin; D000242:Cyclic AMP