[Analysis of the stability of the intermediate fibrin polymers formed in a fibrinogen-thrombin system]

Intermediate fibrin polymers formed from fibrinogen at low thrombin concentrations under physiological conditions are studied for their stability. Smith's statement that intermediate fibrin oligomers are inert molecules whose further self-assembly is possible only under additional thrombin activation was not supported. It is shown that the intermediate fibrin polymer stability at pH 7.4 is not high because of a strong tendency to aggregation and the higher molecular weight of the polymer the less its stability. The polymer stability in solution increases with pH. Stability of soluble fibrin complexes in solution depends on their size, defined by environmental conditions and on the quantity of fibrinogen present.