Inhibition of ovulation in PMSG/hCG-treated immature rats by rotenone, a specific inhibitor of mitochondrial oxidation.
Immature Wistar rats were induced to ovulate by treatment with PMSG and hCG. Control animals ovulated 43.5 +/- 0.36 ova/rat. Intraperitoneal injection of rotenone doses of 0.125, 0.25 and 0.50 mg/kg reduced the ovulation rate to 24.0 +/- 3.08, 8.0 +/- 0.88 and 1.5 +/- 0.44 ova/rat, respectively. The rotenone significantly reduced ovarian cytochrome oxidase activity and progesterone production, but not production of oestradiol or testosterone. Thyroxine treatment at a dose of 5 mg/kg s.c. reversed the rotenone inhibition of ovulation. The results suggest that an increase in mitochondrial respiration is an essential feature of the ovulation process in mammals.
D000818:Animals; D006063:Chorionic Gonadotropin / Q000037:antagonists & inhibitors*; D003576:Electron Transport Complex IV / Q000378:metabolism; D005260:Female; D006064:Gonadotropins, Equine / Q000037:antagonists & inhibitors*; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D006080:Ovarian Follicle / Q000201:enzymology; D010060:Ovulation / Q000187:drug effects*; D010084:Oxidation-Reduction; D051381:Rats; D011919:Rats, Inbred Strains; D012402:Rotenone / Q000494:pharmacology*
D006063:Chorionic Gonadotropin; D006064:Gonadotropins, Equine; D012402:Rotenone; D003576:Electron Transport Complex IV