Inhibitory effect of clomiphene citrate on the conversion of 13,14-dihydro-15-keto-prostaglandin F2 alpha to 13,14-dihydro-prostaglandin F2 alpha in rat ovary.
The effects of clomiphene citrate (clomiphene) on the in vitro conversion of 13,14-dihydro-15-keto-prostaglandin F2 alpha (15KD-PGF2 alpha) to 13,14-dihydro-prostaglandin F2 alpha (13,14H2-PGF2 alpha) in the presence of rat ovarian homogenate, and the relationship between clomiphene and gonadotropin or estrogen in the conversion were investigated. Although clomiphene inhibited the increased conversion of 15KD-PGF2 alpha to 13,14H2-PGF2 alpha by pregnant mare serum gonadotropin (PMS) in rat ovary, the drug did not inhibit the decreased conversion of 15KD-PGF2 alpha by estradiol. The 3-day administration of clomiphene reduced the conversion of 15KD-PGF2 alpha to 13,14H2-PGF2 alpha dose-dependently. A single administration of clomiphene also decreased the conversion, and this decreasing effect was similar to that of estradiol. On the other hand, the repeated administration of clomiphene decreased the ovarian and uterine weights and also inhibited the increase of the uterine weight by PMS or estradiol. These results suggest that clomiphene affects the ovarian enzyme catalyzing the conversion of 15KD-PGF2 alpha to 13,14H2-PGF2 alpha.
D000818:Animals; D002996:Clomiphene / Q000494:pharmacology*; D015237:Dinoprost / Q000031:analogs & derivatives*; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D006064:Gonadotropins, Equine / Q000494:pharmacology; D066298:In Vitro Techniques; D010053:Ovary / Q000187:drug effects* / Q000378:metabolism; D011460:Prostaglandins F / Q000378:metabolism*; D051381:Rats; D011955:Receptors, Drug; D011960:Receptors, Estrogen / Q000187:drug effects; D014599:Uterus / Q000187:drug effects
D006064:Gonadotropins, Equine; D011460:Prostaglandins F; D011955:Receptors, Drug; D011960:Receptors, Estrogen; D002996:Clomiphene; C026527:13,14-dihydroprostaglandin F2alpha; C008228:15-keto-13,14-dihydroprostaglandin F2alpha; D004958:Estradiol; D015237:Dinoprost