title: Protective and specificity-conferring mechanisms of mineralocorticoid action.
abstract: Several experiments using both the in vivo rat bioassay and the isolated toad bladder preparation have been reported that lend support to the hypothesis that the enzyme 11 beta-hydroxysteroid dehydrogenase (11 beta-OHSD), in mineralocorticoid (MC) target tissues, acts as a "protective" mechanism that prevents endogenous glucocorticoids (GCs) from causing MC receptor-mediated effects on Na+ and K+. Additional experiments have also indicated that a second distinct protective mechanism exists that prevents endogenous MCs from eliciting excessive MC receptor-mediated Na+ retention. This second protective mechanism may involve steroid-metabolizing enzymes other than 11 beta-OHSD. Since the specific GC agonist, RU28362, can elicit Na+ retention and K+ secretion, it is possible that a third protective mechanism exists whereby renal 11 beta-OHSD prevents endogenous GCs from eliciting GC receptor-mediated effects on Na+ and K+.
authors.forename: D J
authors.initials: DJ
authors.lastname: Morris
authors.forename: G W
authors.initials: GW
authors.lastname: Souness
mesh_terms: D042842:11-beta-Hydroxysteroid Dehydrogenases; D000450:Aldosterone / Q000378:metabolism; D000818:Animals; D004435:Eating; D006035:Glycyrrhiza; D006801:Humans; D006913:Hydroxysteroid Dehydrogenases / Q000502:physiology; D008659:Metabolic Diseases / Q000378:metabolism; D008901:Mineralocorticoids / Q000378:metabolism / Q000502:physiology*; D010946:Plants, Medicinal; D011188:Potassium / Q000378:metabolism; D011965:Receptors, Glucocorticoid / Q000378:metabolism; D012964:Sodium / Q000378:metabolism
chemical_list: D008901:Mineralocorticoids; D011965:Receptors, Glucocorticoid; D000450:Aldosterone; D012964:Sodium; D006913:Hydroxysteroid Dehydrogenases; D042842:11-beta-Hydroxysteroid Dehydrogenases; D011188:Potassium