title: Prostaglandin E production by uteri of ovariectomized pregnant rats receiving antiprogesterone steroid or in which progesterone has been withdrawn.
abstract: Antiprogesterone steroid, ZK98299 (Schering, Germany) or RU38486 (Roussel Uclaf, France), has been administered to ovariectomized early pregnant rats receiving continuous steroid replacement. At 24 h later, uterine explants of rats treated with ZK98299 produced significantly greater amounts of prostaglandin E (PGE) than did controls or animals treated with RU38486. The PGE/PGF2 alpha production ratio for uteri of rats treated with ZK98299 or RU38486 was markedly lowered compared to controls, and a significant decrease occurred in the PGE/6-keto PGF1 alpha production ratio for rats treated with RU38486. For ovariectomized early pregnant rats in which progesterone has been withdrawn, a significant reduction in uterine PGE production occurred when compared to control animals. There was also a marked decrease in PGE/PGF2 alpha production ratio, and the PGE/6-keto PGF1 alpha production ratio tended to be lowered relative to controls. The stimulated production (as by ZK98299) or unchanged production of PGE (as by RU38486) indicates a selective action on uterine PGE synthesis among the antiprogesterone steroids, and these findings cannot be explained simply in terms of a blockage of progesterone receptors.
authors.affiliation: Department of Anatomy, University of Otago, Dunedin, New Zealand.
authors.forename: P V
authors.initials: PV
authors.lastname: Peplow
mesh_terms: D015121:6-Ketoprostaglandin F1 alpha / Q000096:biosynthesis; D000818:Animals; D015237:Dinoprost / Q000096:biosynthesis; D005260:Female; D006067:Gonanes / Q000494:pharmacology; D066298:In Vitro Techniques; D015735:Mifepristone / Q000494:pharmacology; D010052:Ovariectomy; D011247:Pregnancy; D011374:Progesterone / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D011458:Prostaglandins E / Q000096:biosynthesis*; D051381:Rats; D014599:Uterus / Q000187:drug effects* / Q000378:metabolism
chemical_list: D006067:Gonanes; D011458:Prostaglandins E; D015735:Mifepristone; D011374:Progesterone; D015121:6-Ketoprostaglandin F1 alpha; D015237:Dinoprost; C053238:onapristone