Reversal of platelet aggregation by aortic microsomes

Abstract

The microsomal fraction of dog aortas inhibited human platelet aggregation induced by arachidonic acid, ADP, or thrombin. When aortic microsomes were added to a preparation of irreversibly aggregated platelets, the aggregates dispersed after 4–6 minutes. The fact that aortic microsomes inhibit platelet aggregation induced by ADP suggests that its effect is probably on the cellular function of platelets and not in direct competition against thromboxane A 2.