Effects of anti-progesterone compound RU486 on ovulation in immature mice treated with PMSG/hCG.
The effects of RU486, a competitive antagonist of progesterone, on ovulation were studied in PMSG/hCG-treated immature mice. PMSG/hCG was administered to 3-week-old female mice to induce ovulation. A dose of 0.5 mg of RU486 was administered 3 h before hCG injection, simultaneously with hCG injection, or 3, 4.5, 6, 7.5 or 9 h after hCG administration. The lowest number of ovulated eggs was observed in the group given RU486 6 h after hCG injection. Although the mean number of ovulated eggs was only 4.4 in this group, it was increased to 25.7 by supplementary administration of 2.0 mg of progesterone. It was demonstrated that RU486 had inhibitory effects on ovulation, and the inhibition could be prevented by supplementary administration of progesterone.
Kanayama
K
K
Department of Veterinary Medicine, College of Agriculture and Veterinary Medicine, Nihon University, Kanagawa, Japan.
Sankai
T
T
Nariai
K
K
Endo
T
T
Sakuma
Y
Y
D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D004338:Drug Combinations; D005260:Female; D006064:Gonadotropins, Equine / Q000494:pharmacology*; D007279:Injections, Subcutaneous; D051379:Mice; D015735:Mifepristone / Q000494:pharmacology*; D010060:Ovulation / Q000187:drug effects*; D010062:Ovulation Induction; D010063:Ovum / Q000166:cytology; D011374:Progesterone / Q000037:antagonists & inhibitors* / Q000502:physiology; D013047:Specific Pathogen-Free Organisms
D006063:Chorionic Gonadotropin; D004338:Drug Combinations; D006064:Gonadotropins, Equine; D015735:Mifepristone; D011374:Progesterone