Characterization of the beta-adrenergic receptor on the human platelet: a beta 2-subtype.
The human platelet beta-adrenergic receptor was characterized by using the ability of different drugs to stimulate the adenylate cyclase activity and the effects of various beta-antagonists to block the isoprenaline-stimulated adenylate cyclase activity. Isoprenaline was found 10 times more potent than adrenaline and 1000 times more potent than noradrenaline in stimulating the adenylate cyclase activity in these cells. Isoprenaline-stimulated activity was blocked by the non-selective beta-antagonists propranolol and alprenolol and by the beta 2-selective antagonist IPS 339 and prenalterol. Metoprolol, a beta 1-selective blocker, was without effect on the isoprenaline-stimulated adenylate cyclase activity. We conclude from our findings that the beta-adrenergic receptor type on the human platelet is mainly of the beta 2-subtype.
D000262:Adenylyl Cyclases / Q000378:metabolism*; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D001792:Blood Platelets / Q000201:enzymology / Q000502:physiology*; D000242:Cyclic AMP / Q000032:analysis; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D011943:Receptors, Adrenergic, beta / Q000032:analysis*
D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D011943:Receptors, Adrenergic, beta; D000242:Cyclic AMP; D000262:Adenylyl Cyclases