Influence of Plasmin Inhibitors on Differentiating Digestion between Fibrinogenolysis and Fibrinolysis

It was noted that fibrinogen as well as fibrin were digested almost at the same rate with plasmin, irrespective if it was pre-activated or natively activated in the purified reaction mixture. Fibrinogen digestion, however, was markedly inhibited compared to fibrin.digestion in normal human plasma after the addition of UK. The same differentiating digestion was observed after the addition of UK to the mixture of fibrinogen/fibrin, plasminogen and plasma fraction containing α2-macroglobulin or αrantitrypsin, while the differentiation has not occurred in the mixture of fibrinogen/fibrin and plasmin-α2-macroglobulin complex which was prepared preliminarily. It was postulated that the differentiating digestion between fibrinogen and fibrin was possible under the coexistence of native plasmin and plasmin inhibitors.