In vitro comparison of fibrinolytic activity of plasminogen activators using a thrombelastographic method: in vivo evaluation of the B-chain-streptokinase complex in the dog model using pre-titered doses.

Thrombelastography was used to quantitatively compare the clot-lysing efficiency of 6 different plasminogen activators, using human whole blood, pooled normal plasma, and platelet rich plasma. The activators compared were the B-chain-streptokinase complex, the plasmin-streptokinase complex, the mini-plasminogen-streptokinase complex, tissue plasminogen activator, streptokinase, and urokinase. The most efficient activator found was the B-chain-streptokinase complex. This complex was 4.0 times more effective than streptokinase, 3.0 times more effective than the plasmin-streptokinase complex, 1.3 times more effective than the mini-plasminogen-streptokinase complex, 2.3 times more effective than tissue plasminogen activator, and 16.0 times more effective than urokinase. Although there were differences in both the coagulation and fibrinolysis thrombelastographic patterns between plasma and whole blood, the comparative efficiencies of each activator were the same with either plasma or blood. The B-chain-streptokinase complex was evaluated as a thrombolytic agent in clot-lysis experiments in the jugular vein in the dog model, using a thrombelastographic method to determine the minimum dose of activator necessary for clot-lysis. With 6 dogs infused locally with 0.25 mg (8000 I.U.) of the plasmin-streptokinase complex, the cumulative clot-lysis was 18.0 +/- 3.0% with the first dose, 33.0 +/- 2.1% with the second dose, and 55.2 +/- 8.6% with the third dose. With 6 dogs infused locally with 0.03 mg (2000 I.U.) of the B-chain-streptokinase complex, the cumulative clot-lysis was 30.6 +/- 6.4% with the first dose, 54.4 +/- 9.6% with the second dose, and 80.2 +/- 9.0% with the third dose.