Enhancement of the Activity of Optimum Concentrations of Urokinase by the Venom of Echis carinata

THE venom of Echis carinata (saw-scaled or carpet viper) is known to have powerful haemotoxic actions, promoting coagulation in whole blood or plasma and digesting fibrin1. We have recently investigated the action of this venom on the fibrinolytic enzyme system using the caseinolytic assay system of Remmert and Cohen2 as modified by Alkjaersig3. Urokinase (2,000 U/ml.) was substituted for streptokinase, and 0.1 molar phosphate buffer for acid and alkali. Results are expressed in casein units/ml. Where Echis venom was used, 0.5 ml. of a 1 mg/ml. solution of a desiccator-dried preparation reconstituted in 0.9 per cent saline was incorporated in the system in place of 0.5 ml. of the phosphate buffer used in the assay. Similarly, buffer was substituted for urokinase and plasminogen in the experiments in which these reagents were omitted.