title: Effect of a single oral dose of aspirin on the platelet aggregation response to arachidonic acid.
abstract: 1 The platelet aggregation response to arachidonic acid ex vivo was measured in six volunteers daily before and for 10 days after a single oral dose of 600 mg aspirin. 2 Arachidonic acid induced aggregation of platelets from all subjects before aspirin and aggregation occurred after an interval which varied inversely with the concentration of arachidonic acid. No aggregation occurred for 4 days after aspirin; a reduced response, compared with pre-aspirin values, was obtained on the 5th, 6th and 8th day. The values on days 7, 9 and 10 were not consistently different from the pre-aspirin values. In 6 subjects 24 h after aspirin ingestion the addition of 10--25% v/v normal platelets restored the aggregation response. 3 It is concluded that aspirin has an effect on the platelet precursors in the marrow in addition to its effect on circulating platelets.
mesh_terms: D000328:Adult; D001095:Arachidonic Acids / Q000494:pharmacology*; D001241:Aspirin / Q000494:pharmacology*; D004347:Drug Interactions; D005260:Female; D006801:Humans; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects*; D013997:Time Factors
chemical_list: D001095:Arachidonic Acids; D001241:Aspirin