On the Inhibiting Effect of ε-Amino Caproic Acid upon the Fibrinolytic System During „Spontaneous Activation”

Summary

The effect of ε-ACA (ε-amino caproic acid) upon the factors of the fibrinolytic system contained in a human euglobulin preparation was studied during “spontaneous activation“. The results obtained with the bovine fibrin plate method, the clot lysis, and the casein tests demonstrated a strong inhibitory effect of ε-ACA on the formation of a serum plasminogen activator and on the conversion of plasminogen into plasmin by this activator resulting in a “potentiated inhibition“. On the other hand, no inhibition of plasmin could be found with ε-ACA in concentrations below 0.1 molar. In tests on human fibrin plates finally it became obvious that the human serum plasminogen activator contained in purified human plasmin preparations, having a much higher specificity towards the human plasminogen than the bovine one becomes inhibited by relatively low ε-ACA concentrations. The significance of these results for the inhibitory effect of ε ACA on the fibrinolytic system in vivo was discussed.

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