Fibrinolysins of human plasma. A comparison of fibrinolytic plasma from normal subjects and from cadaver blood with plasmin prepared by activation with chloroform

Abstract

Fibrinolytic plasma clots made in the presence of free calcium lyse less rapidly than those made in its absence. The effect is not due to activation by excess citrate and not, probably, to a direct inhibition by Ca ions. Fibrin clots made from exercise plasma remain constant in amt. for a variable time and then lyse completely within a comparatively short time. In contrast to plasmin prepared by chloroform activation, samples of lysin from living subjects and from cadavers were not inhibited by normal plasma and did not digest fibrinogen. The ratios of activities of given quantities of cadaver lysin and plasmin on fibrinogen and plasma clots were different. Cadaver lysin and plasmin could not be differentiated with regard to opt. pH of activity and stability; both were found in the euglobulin fraction. Fibrinolysin in plasma from living subjects and cadaver lysin may differ only quantitatively; neither is identical with plasmin. Attempts to demonstrate a kinase have been inconclusive.