In Vitro Studies on Fibrinogenolysis Induced by Streptokinase

Abstract

In vitro fibrinogenolysis, initiated by SK, has been studied with the following results:

1) SK-treated plasma or eugblobulin fraction, non-clottable by thrombin and souluble on heating, may still contain appreciable amounts of genuine fibrinogen. Therefore, an exact quantitative estimation of fibrinogenolysis is difficult.

2) For semiquantitative estimation of fibrinogenolysis, the thrombin time of citrated plasma is a reliable and sensitive method, suitable for comparative studies. For clinical purposes, also the dilution method of Schneider can be used.

3) Fibrinogen split products mainly inhibit the polymerization-aggregation process. Further, such products are incorporated in clots formed in mixtures of genuine and proteolysed fibrinogen.

4) SK is effective within a wide range of concentrations. In order to obtain a rapid and extensive fibrinogenolysis, about 5 SKT should be used.

5) Divalent cations inhibit the fibrinogenolytic process.

6) The effect of SK is markedly enhanced at temperatures higher 37° C.

7) In a “plasma-clot” system, fibrinogen is more sensitive to SK than fibrin.