Studies on the relationship between amidolytic activity using S-2251, fibrinolytic activity and antigenicity of plasminogen

Amidolytic activity, fibrinolytic activity and antigenicity of plasminogen were estimated in 16 healthy people, 21 patients with collagen diseases or collagen like disorders, 30 with hepatic diseases and 11 other diseases. Amidolytic activity was estimated by chromogenic substrate of S-2251. Fibrinolytic activity was estimated by means of measuring the lytsis area on Bovine plasminogen free fibrin plate, in which euglobulin fraction with SK was dropped. Aniigenicity was estimated by the single radial immunodiffusion method.The results were as follows:1) The value of amidolytic activity, fibrinolytic activity and antigenicity of plasminogen were each 101±15%, 264±36mm and 14.1±1.9mg/dl in healthy people.2) Amidolytic activity of plasminogen was well correlated with antigenicity in our cases. However, fibrinolytic activity showed a decreasing tendency and its activity was not correlated with amidolytic activity and antigenicity in collagen diseases or collagen like disorders. Fibrinolytic activity was moderately correlated with antigenicity and amidolytic activity in healthy people and patients with hepatic diseases. It was suggested that fibrinolytic activity was inhibited by inhibitors in the euglobulin fraction, and an increase of inhibitors was markedly seen in collagen diseases or collagen like disorders.