[Experimental study of the antiproteinase activity of human alpha-2-macroglobulin concentrate]

20 series of alpha-2-macroglobulin (alpha 2-M) preparations with a specific activity of 15 +/- +/- 1 IU/mg were obtained by means of semi-industrial fractionation of human blood plasma Kohn 111 residue including polyethylene glycol and ethanol treatment. The preparations obtained inhibited proteolytic enzymes of fibrinolytic, kinin and blood coagulation systems as well as plant and bacterial proteinases. After intravenous administration of the alpha 2-M preparation into rats at a dose of 850-11,000 IU/kg the globulin concentration was correspondingly increased by 23-25% in blood. The half-time of excretion of the alpha 2-M therapeutic dose (2,700-5,700 IU/kg) was about 6.6-13,9 hrs which was 9-20-times higher as compared with the corresponding value for contrical. In the experimental proteolysis (effect of trypsin at a dose of 470-6,670 KU/kg) preparation of alpha 2-M, administered at a dose of 2,000-6,000 IU/kg, exhibited a distinct antiprotease action with a 1.5-1.7-fold increase in the rate of inactivation and excretion of trypsin. The alpha 2-M preparation was shown to be highly effective in prophylactic treatment. The advantages of antiprotease drugs based on human alpha-2-macroglobulin are discussed.