Fibrinolytic Activities present in Human Blood Platelets

BLOOD platelets have been shown to contain antiplasmin activity 1–3 . The experiments to be described in this communication demonstrate that blood platelets interfere in still another way in fibrinolysis. The fibrinolytic activity brought about by streptokinase comprises two steps 4 : (1) activation of a proactivator which could be identical in man with plasminogen ; (2) transformation of plasminogen to plasmin by the activator, resulting from reaction (1).