Abstract
The pharmacological effects of antiestrogens on ovarian aldo-keto reductase and ovulation were investigated in rats. The activities of reduction of 13, 14-dihydro-15-keto-PGF2α, 4-benzoylpyridine and menadione in ovarian cytosol were significantly decreased by antiestrogen treatments, and the ovulation was completely inhibited. However, administration of luteinizing hormone-releasing hormone at 3:00 p.m. on the day of proestrus restored both enzyme activities and ovulation, which were inhibited by antiestrogens, to control levels. These results indicate that nonsteroidal antiestrogen inhibits the luteinizing hormone surge on the day of proestrus in 4-day cycling rats and that ovarian aldo-keto reductase may be closely involved in the ovulatory process in rats.
