title: Dynamics of alpha-adrenergic inhibition of the adenyl cyclase-cyclic amp system in human adipose tissue.
abstract: In short-term incubations of fat cells isolated from human adipose tissue, noradrenaline (0.2-2x10--5 M), a mixed alpha and beta-adrenergic agonist, stimulated only slightly cyclic AMP accumulation. In the presence of the alpha-adrenergic blocking agent phentolamine (0.05-5mug/ml), noradrenaline markedly augmented the amount of labelled cyclic nucleotide. The stiumlatory effect of noradrenaline and noradrenaline plus phentolamine was abolished by propranolol (0.1-10 mug/ml). Theophylline (10--4-10--3 M) slightly increased the (3-H) cyclic AMP levels per se and magnified the stiumulatory action of other agents, but did not mimic the potentiating effect of phentolamine on noradrenaline action.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D000273:Adipose Tissue / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism*; D003864:Depression, Chemical; D006801:Humans; D009638:Norepinephrine / Q000494:pharmacology*; D010646:Phentolamine / Q000494:pharmacology*; D011433:Propranolol / Q000494:pharmacology*; D013268:Stimulation, Chemical; D013806:Theophylline / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D011433:Propranolol; D013806:Theophylline; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D009638:Norepinephrine; D010646:Phentolamine