THE ANTIPROTEOLYTIC ACTIVITY OF SERUM : II. PHYSIOLOGICAL SIGNIFICANCE. THE INFLUENCE OF PURIFIED TRYPSIN INHIBITOR ON THE COAGULATION OF THE BLOOD.

1. Serum antitrypsin and pancreatic trypsin inhibitor inhibited the coagulation of plasma in vitro. 2. This could be largely prevented by trypsin. 3. The anticoagulant action of the trypsin inhibitor was apparently due to its antiprothrombic action. It had no appreciable antithrombic action. 4. Examination of the blood of two hemophiliacs indicated that the prolonged coagulation time of their blood is not due to an excess of trypsin inhibitor. 5. Examination of the blood of heparinized dogs indicated that heparin does not appreciably contribute to the antiproteolytic activity of the serum.