[Inhibitor of fibrin self-assembly].

The thermostable inhibitor with a molecular mass 1750 +/- 100 was found in human, bovine and albino rat blood sera. A ninhydrin-positive product containing no carbohydrates, lipids, nucleic acids was obtained while purifying the inhibitor by combining column ion-exchange chromatography and partition thin layer chromatography. An analogous inhibitor is extracted from the tissue of liver, kidneys, lungs, spleen, duodenum, heart, m. striatum, brain, aorta, where its content is higher than in the blood serum. The inhibitor differs from the already known ones in molecular mass, resistance to heating and dialysis. An assumption is advanced on its participation in maintaining the liquid blood state under conditions providing a possibility of accelerated thrombinogenesis and thrombin fibrinogen interaction.