Mechanism of action of aspirin on platelet function

Inhibition of platelet aggregation and of the reaction of liberation of platelet factor 3 under the influence of aspirin was shown to be due to the action of the drug not only on the platelets, but also on plasma cofactors: In experimentsin vitro the blood plasma of rats receiving aspirin reduced the aggregating power of the platelets of intact animals; blood plasma of intact rats increased the aggregating power and accessibility of factor 3 of the platelets of animals receiving aspirin.