[The anticoagulant property of a lipoid anticoagulant and the mechanism of its influence on hemocoagulation].

A lipoid anticoagulant (LA) from human brain tissue was shown to possess a higher anticoagulant activity than previously obtained preparations. It has been established that out of four phospholipids present in LA, only phosphatidyl serine inhibits the coagulant activity of plasma. In isolated hemocoagulating systems LA and phosphatidyl serine were shown to inhibit prothrombin conversion catalyzed by thrombokinase and to exert the antithrombic action in the system thrombin--fibrinogen. Kinetic study of phosphatidyl serine- and LA-induced inhibition of thrombine formation and the thrombine--fibrinogen reaction by conjugated inhibition. Similar kinetic behaviour, observed upon inhibition of both processes by phosphatidyl serine and LA suggest that phosphatidyl serine is a main anticoagulant agent of LA.