[Characteristic of antithromboplastic activity of human blood serum].

The ability of human blood serum for inactivating tissue thromboplastin is established to be due to the presence of two inhibitors: thermolabile inhibitor characterized by a progressive effect and thermostable one having an instant effect. Thromboplastin inhibition by the thermolabile inhibitor is partial, whereas inhibition by the thermostable one is completely reversible. In the latter case inhibition is intermediate character, between the competitive and incompetitive one. The inhibitory activity is found in Cohn's fraction V, is removed during DEAE-cellulos chromatography and gel chromatography with the first portions of eluating liquid.