title: Regulation of 17 beta-hydroxysteroid oxydoreductase of the Xenopus laevis follicle by gonadotropin and prolactin.
abstract: Ovarian follicles of Xenopus laevis, incubated in vitro actively metabolized radioactive 4-androstene-3, 17-dione to testosterone, indicating the presence of a 17 beta-hydroxysteroid-oxydoreductase (17 beta-HSOR). This enzymatic activity was found to be solely localized in the follicular envelopes. In vitro treatment of follicles with hCG for 2 hr induced a 40% decrease of the 17 beta-HSOR activity. The gonadotropin-induced inhibition was dose-dependent and only observed with gonadotropic LH-like hormones. Concomitant treatment with prolactin completely prevented the hCG effect.
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000735:Androstenedione / Q000378:metabolism; D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D007986:Luteinizing Hormone / Q000494:pharmacology; D006080:Ovarian Follicle / Q000187:drug effects / Q000201:enzymology*; D011388:Prolactin / Q000494:pharmacology*; D014982:Xenopus laevis / Q000378:metabolism*
chemical_list: D006063:Chorionic Gonadotropin; D000735:Androstenedione; D011388:Prolactin; D007986:Luteinizing Hormone; D015067:17-Hydroxysteroid Dehydrogenases; C032690:3-alpha-(17-beta)-hydroxysteroid dehydrogenase (NAD(+))