title: Specific progesterone receptors in dimethylbenzanthracene (DMBA)-induced mammary tumors.
abstract: Properties of a progesterone receptor present in the cytosol (105,000 xg supernatant) of dimethylbenzanthracene (DMBA)-induced mammary tumors were studied using the highly potent progestin [3H]R 5020 (17, 21-dimethyl-19-nor-pregna-4, 9-diene-3,20-dione). As shown by sucrose gradient analysis, specific binding of [3H] R 5020 is associated with components migrating at 7-8S and 4S. Low affinity binding of the synthetic progestin is eliminated by treatment with dextran-coated charcoal. [3H] R 5020 binding is highly progestin-specific since it is easily displaced by unlabelled norgestrel, R 5020 and progesterone while estradiol-17beta, dihydrotestosterone, testosterone, testosterone and diethylstilbestrol have much lower activity. Dexamethasone and cortisol have little, if any, effect on [3H] R 5020 binding.
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene; D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D003600:Cytosol / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology; D004958:Estradiol / Q000378:metabolism; D005260:Female; D006854:Hydrocortisone / Q000494:pharmacology; D007700:Kinetics; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism*; D011485:Protein Binding; D051381:Rats; D011956:Receptors, Cell Surface / Q000187:drug effects
chemical_list: D011956:Receptors, Cell Surface; D011374:Progesterone; D004958:Estradiol; D015127:9,10-Dimethyl-1,2-benzanthracene; D003907:Dexamethasone; D006854:Hydrocortisone