Procoagulant activity of platelet arachidonic acid metabolites.

1 Arachidonate metabolites have been extracted from indomethacin-treated human platelets after incubation with arachidonic acid. 2 After separation from platelet phospholipids, the extracts promoted the generation of large amounts of thrombin in normal plasma, but not in plasma devoid of lipoproteins. 3 The procoagulant activity was associated with a minor component of the mixture, which was active at concentrations below 10 micrograms ml-1. 4 The activity was similar to that of autoxidised arachidonic acid previously described. 5 Platelet arachidonic acid metabolites could play a role in the coagulation system.