THE INHIBITORY EFFECT OF LARGE CONCENTRATIONS OF STREPTOKINASE AS RELATED TO PROTEOLYTIC ACTIVITY AND PROACTIVATOR FUNCTION OF HUMAN EUGLOBULIN.

The inhibitory effect of large concentrations of SK on clot lysis and fibrinogenolysis has been studied, giving the following results: 1) Inhibitory concentrations of SK are related to the amount of human euglobulin fraction (HEF) present. A stoichiometric relationship between SK and HEF seems to exist. 2) The inhibitory effect of SK-HEF can be prevented by addition of bovine euglobulin fraction (BEF). 3) In order to obtain maximum activation of bovine plasminogen and minimum activation of human plasminogen (i.e. sensitive assay system for “proactivator”) inhibitory concentrations of SK are necessary. In addition, the content of “proactivator” must be low as compared with that of bovine plasminogen, to avoid human plasmin effect.