Toxins Affecting Blood Coagulation and Fibrinolysis

This chapter deals with all naturally occuring substances which cause a change in the quantity or quality of coagulation induced by platelets and/or plasma factors as determined in vitro. Formation of the streptokinase-plasminogen complex reveals an active center in the plasminogen molecule which is identical with the active site of plasmin responsible for fibrinolysis. Plasminogen can be activated directly, or via a proactivator, by proteolytic enzymes, such as trypsin, or autocatalytically by plasmin. Defibrination was accompanied by a simultaneous decrease in plasminogen concentration, although no activating effect of the drugs on plasminogen was detected. In humans the drug is well tolerated and may be useful in prevention and treatment of thromboembolic diseases. Ocrase was used in human clinical experiments in only 17 patients with peripheral artery occlusion, pelvic vein thrombosis and other thromboembolic diseases. The total amount of ocrase administered in repeated infusions ranged from 80 mg to 800 mg per patient.