Basic mechanisms of hemostasis.

The marked, prolonged, more generalized vasoconstriction Profilbrinolysim (plasminogen, tryptogen, prolysin, lytic factor, etc.) found in plasma and serum is activated to fibrinolysin (plasmin, tryptase, tissue lysin, etc.) by a flbrino-lysokhiase (found in tissues, especially lung and uterus). The action of the kinase is probably inhibited or antagonized by inhibitors present in plasma and serum (anti-flbrinolysokintases). The active fibrinolysin is antagonized and inhibited by antiflbrinoly- sin (antiplasmin), also found in plasma and serum. Alternatively, a proteolytic enzyme (similar to, but not identical with fibrinolysin) of prostatic origin may also lyse fibrin clots (disseminated prostatic carcinoma). Moreover, other proteolytic enzymes may also be present in human I)lasIlI as inert precursors and be occasionally activated by similar mechanisms.