title: Permissive action of glucocorticoids on catecholamine-induced lipolysis: direct "in vitro" effects on the fat cell beta-adrenoreceptor-coupled-adenylate cyclase system.
abstract: Exposure of adipose tissue fragments to dexamethasone leads to enhanced lipolytic and cyclic AMP responses of isolated fat cells to isoproterenol. This permissive effect of the steroid is dose-dependent, prevented by the glucocorticoid receptor antagonist RU 38486, maximum after 48 h exposure to 10 nM dexamethasone and affects only the amplitude of the maximal response (+50%). Exposure to dexamethasone also induces an increase in both the number of beta-adrenergic receptors (+30%), and the adenylate cyclase-catalytic activity (+64%) and - responses to GTP (+114%) and isoproterenol (+55%). These data strongly suggest that the permissive effect of glucocorticoids towards lipolysis "in vivo" results at least in part from a glucocorticoid-receptor mediated action of these hormones on the fat cell membranous components involved in the beta-adrenergic control of lipolysis.
authors.affiliation: Department of Biochemistry, Faculty of Medecine Paris-Quest, C.H.I., Poissy, France.
authors.forename: D
authors.initials: D
authors.lastname: Lacasa
authors.forename: B
authors.initials: B
authors.lastname: Agli
authors.forename: Y
authors.initials: Y
authors.lastname: Giudicelli
mesh_terms: D000262:Adenylyl Cyclases / Q000502:physiology*; D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000096:biosynthesis*; D003907:Dexamethasone / Q000494:pharmacology*; D004963:Estrenes / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000502:physiology; D007545:Isoproterenol / Q000494:pharmacology; D008053:Lipid Mobilization / Q000187:drug effects*; D008297:Male; D008345:Manganese / Q000494:pharmacology; D015735:Mifepristone; D051381:Rats; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*
chemical_list: D004963:Estrenes; D011943:Receptors, Adrenergic, beta; D005576:Colforsin; D015735:Mifepristone; D008345:Manganese; D003907:Dexamethasone; D000242:Cyclic AMP; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases; D007545:Isoproterenol