Prostaglandin F2alpha: modification of its abortifacient effect by depo-estradiol cypionate in rats.
Insertion of a Silastic-PVP implant containing 150 mug PGF2alpha into one of the uterine horns or administration of a single subcutaneous injection of 4 mug of Depo-Estradiol Cypionate (ECP) did not induce abortion in pregnant rats. However, a combined treatment with 150 mug of PGF2alpha in a Silastic-PVP implant and 4 mug of ECP induced abortion in all treated rats. Apparently, ECP stimulated endogenous production of PGF and consequently enhanced the effect of the administered 150 mug of PGF2alpha. The release of 3H-PGF2alpha from Silastic-PVP implants was faster after intrauterine or intraperitoneal than after subcutaneous insertion. The release rate of 3H-PGF2alpha from Silastic-PVP implants in vitro was comparable to that observed after subcutaneous placement of similar implants. It is suggested that administration of estrogen combined with PGF2alpha might shorten the interval between treatment with PGF2alpha and abortion. Moreover, a Silastic-PVP implant would lend itself as a better method of administration, releasing PGF2alpha locally, slowly, and continuously.
D000019:Abortifacient Agents / Q000494:pharmacology*; D000028:Abortion, Induced / Q000662:veterinary; D000034:Abortion, Veterinary / Q000139:chemically induced*; D000818:Animals; D003517:Cyclopentanes / Q000008:administration & dosage / Q000031:analogs & derivatives; D004357:Drug Synergism; D004958:Estradiol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D005260:Female; D005333:Fetus / Q000187:drug effects*; D066298:In Vitro Techniques; D011247:Pregnancy; D011262:Pregnancy Trimester, Second / Q000187:drug effects; D011270:Pregnancy, Animal / Q000187:drug effects*; D011422:Propionates / Q000008:administration & dosage; D011453:Prostaglandins / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012828:Silicones; D013997:Time Factors; D014316:Tritium
D000019:Abortifacient Agents; D003517:Cyclopentanes; D011422:Propionates; D011453:Prostaglandins; D012828:Silicones; D014316:Tritium; D004958:Estradiol