A New Blood-Clotting Theory

Abstract

A new blood-clotting theory accepts the fundamentals of the classic "thrombin theory," but stresses the role of active tryptase (proteolytic enzyme'') in the thromboplastic conversion of prothrombin to thrombin. The normal maintenance of the blood in its fluid state is attributed to factors (including heparin) which maintain the enzyme in its natural inactive state, and the pre-requisite of ordinary clotting is the mobilization of active thromboplastic enzyme from plasma and cell or tissue sources. A sufficient excess of free tryptase accounts for such proteolytic side-actions as fibrinolysis (including clot-retraction and lysis of fibrinogen), lysis of thrombin and prothrombin, etc. Interrelations between coagulation anomalies and "im- munological" changes (especially anaphylaxis) suggest a common meeting ground centering around the protease.