Effects of Soy Bean Trypsin Inhibitor on Fibrin Clot Lysis^[*]

Summary

The effect of soy bean trypsin inhibitor (SBTI) on fibrinolysis and blood coagulation was investigated. Clot lysis was recorded by means of thrombelastography. SBTI delays fibrinolysis induced by plasmin and by activators of plasminogen (SK-activator and urokinase). Activator-induced lysis is delayed by a combined effect on activator and plasmin. There appears to exist an equilibrium between highly dissociated compounds of inhibitor with the active agents. The inhibitory effect of SBTI is relatively decreased in clots containing human plasma probably caused by an equilibrium with inhibitory agents in the plasma. SBTI delays thrombin generation in recalcified plasma as well as the effect of thromboplastin, but the effect is weak and requires a concentration 70-100 fold the antifibrinolytic active. The effect on thrombosis is even weaker.

^* Supported by grant HE-05020 to Dr. Tage Astrup, Director of Research, from the U. S. Public Health Service, National Institutes of Health, National Heart Institute.

^** Present adress: Surgical Department H., Copenhagen County Hospital, Gentofte, Denmark.

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