title: Effect of acetaminophen and salicylate on aspirin-induced inhibition of human platelet cyclo-oxygenase.
abstract: Recent studies have shown that salicylic acid, a metabolite of aspirin, effectively competes for the same site on the platelet cyclo-oxygenase enzyme. In the present investigation we have evaluated the effect of salicylate and acetaminophen on aspirin induced inhibition of cyclo-oxygenase and platelet function. Results of our studies show that both drugs at equimolar concentrations had no inhibitory effect on aspirin induced blockage of cyclo-oxygenase or platelet function. Even at higher concentrations acetaminophen failed to protect cyclo-oxygenase or prevent inhibition of platelet function by aspirin. Salicylate at concentrations above 5 mM effectively blocked the inhibition of cyclo-oxygenase activity and platelet aggregation in response to arachidonate.
mesh_terms: D000082:Acetaminophen / Q000494:pharmacology*; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology; D001241:Aspirin / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects / Q000201:enzymology*; D016861:Cyclooxygenase Inhibitors; D006801:Humans; D012459:Salicylates / Q000494:pharmacology*; D013929:Thromboxane B2 / Q000097:blood
chemical_list: D001095:Arachidonic Acids; D016861:Cyclooxygenase Inhibitors; D012459:Salicylates; D016718:Arachidonic Acid; D000082:Acetaminophen; D013929:Thromboxane B2; D001241:Aspirin