title: Interaction of synthetic progestagens with renal mineralocorticoid receptors.
abstract: Progesterone increases urinary sodium excretion at least in part by competition for renal mineralocorticoid receptors. In contrast, synthetic progestagens do not increase sodium excretion or even cause a slight sodium retention. We therefore compared the ability of progesterone and 12 progesterone like compounds to displace [3H]aldosterone from binding at cytoplasmic mineralocorticoid receptors in rat kidney. All synthetic progesteronelike steroids were less active than progesterone in competing with [3H]aldosterone for the receptor binding: progesterone 100%, 11 beta-OH progesterone 50%, 17 alpha OH-progesterone 24% and 16 alpha-methyl-progesterone 3%. Derivates of 17 alpha OH-progesterone (medrogestone 5%, dydrogestone 4%, medroxy progesterone-acetate 2% and chlormadinone-acetate 0.5%) were more potent than 19-nor-testosterone derivates: ethisterone 1%, norethisterone less than 1%, norethindrone less than 1%, norethyl-nodrel less than 1%, and ethynodiol-diacetate less than 1%. The decreased affinity of synthetic progestins for mineralocorticoid receptors explains in part the lack of natriuretic activity of these compounds.
mesh_terms: D000450:Aldosterone / Q000378:metabolism; D000818:Animals; D003600:Cytosol / Q000378:metabolism; D004347:Drug Interactions; D007668:Kidney / Q000378:metabolism*; D008297:Male; D008901:Mineralocorticoids / Q000378:metabolism*; D009318:Natriuresis / Q000187:drug effects; D011374:Progesterone / Q000494:pharmacology*; D045167:Progesterone Congeners / Q000494:pharmacology*; D051381:Rats; D011987:Receptors, Steroid / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism
chemical_list: D008901:Mineralocorticoids; D045167:Progesterone Congeners; D011987:Receptors, Steroid; D000450:Aldosterone; D011374:Progesterone; D012964:Sodium