Intravascular Coagulation and Fibrinolysis by Stapliylocoagiilase. Comparison with Thrombin

Abstract

SummaryIntravascular clotting in rabbits after intravenous injection of 30 N.I.H. units of thrombin/kg and 5/mg/kg of staphylocoagulase were studied. Following determinations were made : clotting time, thrombin time, fibrinogen, factors V, VII, VIII, X, XI and XII, “true prothrombin”, two stage prothrombin, P-P test, prothrombin consumption, fibrinolysis in serum euglobulins, plasminogen, antithrombin III and VI, and coagulase reacting factor. Intravenous staphylocoagulase produced in rabbits precipitous drop of fibrinogen level in a very short time, which was not observed with the dose of thrombin used. Activity of staphylocoagulase in vivo was very much higher than of thrombin, as it could be expected on basis of the in vitro comparison. Together with defibrination caused by staphylocoagulase, fibrinogen breakdown products, identified as antithrombin VI, appear in plasma. There were no such changes observed when thrombin was used. Slight decrease of prothrombin and antithrombin III levels, together with a lack of significant changes in factors V, VII, VIII, X, XI and XII content, were observed after staphylocoagulase injection. Slight increase of CRF content in staphylo co agulase clotted plasma was noted. Fibrinolytic system was not activated during clotting process caused by staphylo-coagulase. Significance of the data obtained is discussed.