title: Induction of human platelet fibrinogen receptors by epinephrine in the absence of released ADP.
abstract: The ability of epinephrine to expose platelet fibrinogen receptors independent of released ADP was assessed using aspirin-treated, gel-filtered platelets. Similar to ADP-induced aggregation, platelet aggregation in response to epinephrine was accompanied by fibrinogen binding. Ten micromolar epinephrine induced a maximum number of platelet fibrinogen receptors in the absence of significant 14C-serotonin release. As indicated by Scatchard analysis, receptors exposed by both epinephrine and ADP had similar affinities for fibrinogen, but epinephrine induced approximately 30% fewer receptors than did ADP. This appears to correlate with the lesser degree of primary aggregation observed with this agent. Studies using phentolamine, a specific alpha-adrenergic antagonist, apyrase, or creatine phosphate/creatine kinase indicate that the exposure of platelet fibrinogen receptors by epinephrine was specific for platelet alpha-adrenergic receptor stimulation and was not the result of released ADP.
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism*; D001241:Aspirin / Q000494:pharmacology; D001792:Blood Platelets / Q000378:metabolism*; D002469:Cell Separation; D003402:Creatine Kinase / Q000378:metabolism; D004492:Edetic Acid / Q000494:pharmacology; D004837:Epinephrine / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D010646:Phentolamine / Q000494:pharmacology; D010974:Platelet Aggregation / Q000187:drug effects; D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface / Q000096:biosynthesis* / Q000187:drug effects; D012701:Serotonin / Q000032:analysis / Q000378:metabolism
chemical_list: D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface; D012701:Serotonin; D000244:Adenosine Diphosphate; D004492:Edetic Acid; D003402:Creatine Kinase; D001241:Aspirin; D004837:Epinephrine; D010646:Phentolamine