title: Effect of an estrogen antagonist on development of blastocysts and implantation in the hamster.
abstract: CI 628 citrate, an estrogen antagonist, was given as a single intraluminal injection (5 micrograms) on day 3 to ovariectomized, progesterone-treated hamsters. This significantly reduced embryo cleavage rate, transformation of morula into blastocyst, and completely inhibited implantation. The effects of the drug could be reversed by estradiol-17B (1 microgram) but not estradiol-17 alpha (1 microgram) injected intraluminally with CI 628 citrate. Our finding suggests a role of estrogen present in hamster preimplantation embryo in the triggering of embryonic differentiation and implantation of the blastocyst.
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects; D006224:Cricetinae; D010064:Embryo Implantation / Q000187:drug effects*; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D008647:Mesocricetus; D009594:Nitromifene / Q000494:pharmacology*; D011247:Pregnancy; D011759:Pyrrolidines / Q000494:pharmacology*
chemical_list: D011759:Pyrrolidines; D004958:Estradiol; D009594:Nitromifene