STUDIES ON THE CLOT-PROMOTING EFFECT OF LARGE CONCENTRATIONS OF STREPTOKINASE.

The clot-promoting effect of large concentrations of streptokinase (SK) has been studied, with the following results:1. SK, in concentration from 600 to about 30 000 units/ml (final concentration) shortens the thrombin time of human citrated plasma.2. The effect is instantaneous, and vanishes after incubation for 2 minutes.3. A plasma factor, present in human, but not in bovine plasma, is required for the effect. The concentration of this factor is critical.4. No clot-promoting effect could be demonstrated with urokinase.5. The clot-promoting and the fibrinogenolytic effects or large concentrations of SK are both inhibited in the prosence of 0.002 per cent epsilon-amino-caproic acid.