ISOLATION AND PROPERTIES OF ANTICOAGULANTS FROM FIBRINOLYSED AND HUMAN HEART-PUMP PLASMAS.

Abstract

A method is described for the isolation from plasma of breakdown products of fibrinogen having anticoagulant properties. Intact fibrinogen is removed by addition of ether (to 11% by volume) and the anticoagulant is then precipitated by 25% ammonium sulphate saturation of the supernatant. With this method, anticoagulant fractions from in vitro lysed human plasma, human heart-pump plasma, and in vivo lysed rabbit plasma have been isolated. The electrophoretic patterns of the fractions isolated from lysed human plasma and heart-pump plasma were similar to that of AFIF and consisted of two main components, one exhibiting the same mobility as intact fibrinogen and another being more electronegative. Both fractions were found to possess antithrombin activity. The fraction isolated from plasma of rabbits injected with fibrinolysin was separated into three main components. The antithrombin activity of lysed plasmas, human and rabbit, increased with increasing pH values, while that of the heart-pump plasma, after an initial increase, seemed to decrease above pH 7.8. In further similarity to AFIF, all fractions counteracted the procoagulant effect of protamine sulphate, but only the fraction isolated from adsorbed lysed plasma showed an antithromboplastic effect as well. Measurement of optical densities at 600 mμ of mixtures of fibrinogen and the anticoagulants, after addition of thrombin, indicated that all anticoagulants: (a) delayed the beginning of polymerization; and (b) decreased the opacity of the resulting clot.No correlation could be established between the variable levels of antithrombin activity of the fraction isolated from the heart-pump plasma and the severity of the condition of the patient.