title: Steroid binding specificity of the hamster uterine progesterone receptor.
abstract: The relative binding affinities (RBA) of 51 steroids were determined for the uterine progesterone receptor of the proestrous hamster. The receptor demonstrated a high specificity for progesterone; most structural modifications to the progesterone molecule resulted in a substantial reduction in binding affinity. Only six steroids had relative binding affinities similar to progesterone (RBA=100): 17 alpha-ethinyl-17 beta-methoxy-4-androsten-3-one (RBA=85); 6 alpha-fluoro-4-pregnene-3,20-dione (RBA=94); 17,21-dimethyl-19-nor-4,9-pregnadiene-3,20-dione (RBA=96); 19-nor-4-pregnene-3,20-dione (RBA=110); 21-fluoro-4-pregnene-3,20-dione (RBA=119); and 17 alpha-ethinyl-17 beta-methoxy-4-estren-3-one (RBA=123).
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D002645:Chickens; D006224:Cricetinae / Q000378:metabolism*; D004962:Estranes / Q000378:metabolism; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D007700:Kinetics; D011278:Pregnanes / Q000378:metabolism; D011374:Progesterone / Q000378:metabolism; D011817:Rabbits; D011980:Receptors, Progesterone / Q000378:metabolism*; D012756:Sheep; D013329:Structure-Activity Relationship; D014599:Uterus / Q000378:metabolism*
chemical_list: D004962:Estranes; D011278:Pregnanes; D011980:Receptors, Progesterone; D011374:Progesterone