Trasylol prevents trypsin-induced shock in dogs.

The effect of simultaneous intravenous administration in the dog of bovine trypsin and Trasylol followed by continued infusion of Trasylol was studied. Special attention was paid to the interchange between the dominating plasma protease inhibitors alpha1-antitrypsin and a-macroglobulins and to the disappearance of Trasylol and its trypsin complexes from the circulation. The following results were obtained: 1) Trypsin was preferentially bound by the alpha-macroglobulins, though Trasylol is a strong trypsin inhibitor. 2) On saturation of the alpha-macroglobulins, a considerable amount of trypsin was bound by alpha1-antitrypsin. 3) Trasylol was bound to the trypsin-alpha-macroglobulin complexes and then rapidly eliminated from the circulation. 4) On saturation of the alpha-macroglobulins, Trasylol was identified in a free form but increasing amounts of Trasylol were also bound to trypsin. This could be explained not only by direct complexation of Trasylol and trypsin but also by a transfer of trypsin from unstable trypsin-alpha1-antitrypsin complexes to free Trasylol.