title: Indirect immunofluorescence studies on the steroid-producing activity of hamster ova.
abstract: Steroidogenesis in the unfertilized hamster ova was investigated by indirect immunofluorescence study. delta 5-3 beta-Hydroxysteroid dehydrogenase (delta 5-3 beta-HSD) activity was found in hamster follicular and ovulatory ova with pregnenolone used as the substrate. A significant quantity of 17 beta-estradiol was detected in the ooplasm of follicular and ovulatory ova. No progesterone was found. The activity of delta 5-3 beta-HSD in follicular and ovulatory ova was inhibited by preincubation with 10 IU of human chorionic gonadotropin (hCG) in 1 ml of phosphate buffer solution. Trilostane, a potent new inhibitor of the delta 5-3 beta-HSD system, was found to inhibit the activity of delta 5-3 beta-HSD in ovulatory ova in 1 ml of phosphate buffer solution at a concentration of 10(-7)M. After these results were obtained, steroidogenesis of hamster ova was suggested in an indirect immunofluorescence study, and the implications of steroidogenesis for oocyte maturation and subsequent fertilization are discussed.
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D006224:Cricetinae; D013196:Dihydrotestosterone / Q000031:analogs & derivatives / Q000494:pharmacology; D004958:Estradiol / Q000096:biosynthesis*; D005260:Female; D005455:Fluorescent Antibody Technique; D008647:Mesocricetus; D009865:Oocytes / Q000254:growth & development / Q000378:metabolism; D010060:Ovulation; D010063:Ovum / Q000378:metabolism*; D010086:Oxidative Phosphorylation Coupling Factors / Q000494:pharmacology; D011374:Progesterone / Q000096:biosynthesis
chemical_list: D006063:Chorionic Gonadotropin; D010086:Oxidative Phosphorylation Coupling Factors; D013196:Dihydrotestosterone; D011374:Progesterone; D004958:Estradiol; D015096:3-Hydroxysteroid Dehydrogenases; C031954:delta(5)-3 beta-hydroxysteroid dehydrogenase; C009954:trilostane