Anticoagulating and non-enzymatic fibrinolytic activities of heparin-antithrombin III and antithrombin III-heparin-thrombin complexes in vitro and in vivo.

The heparin-antithrombin III and antithrombin III-heparin-thrombin complexes were prepared in vitro. The formation of complexes was controlled by crossed electrophoretic and spectrophotometric methods. All the binary and ternary complexes prepared at the weight ratio of components 1: 1: 1 and at some other weight correlations were active as non-crosslinked fibrin solvents and kept this activity in the presence of inhibitors of plasmin fibrinolysis. A considerable prolongation of thrombin time and an increasing of total and in particular non-enzymatic lytic actions of plasma were achieved in 7 and 30 min after intravenous injection of 1 ml 0.1-0.2% solution of heparin-antithrombin III complex in rats. The obtained results of experiments allow to conclude that the heparin-antithrombin III and antithrombin III-heparin-thrombin complexes possess the non-enzymatic fibrinolytic action on non-crosslinked fibrin. The degree of this activity is dependent on the quantitative correlation of heparin-antithrombin III or antithrombin III-heparin-thrombin concentrations during the reaction of complex formation.