[Antithrombin III. Functional role and methods of determination (review)].

Antithrombin III (AT III) is the most important inhibitor of thrombin and other serine proteinases in the system of blood coagulation. AT III not only removes the excess of thrombin from blood but it inhibits the enzyme synthesis. AT III became functionally active in presence of heparin, which operates as a catalyst and accelerates significantly the formation of inactive complexes between AT III and proteinases, which usually developed slowly in absence of the activator.

[Inhibition of fibrin assembly by fragment D and its dimer derived from fibrinogen and stabilized fibrin. Evidence for the two-step type of inhibition].

The influence of purified fragments D and DD on fibrin monomer polymerization has been studied. When applied separately, DD is less strong an inhibitor than D. An addition of small amounts of DD to the reaction mixtures containing D does not change the inhibitory effect, when the concentration of the latter fragment is low.