Collagenase and elastase released during peritonitis are complexed by plasma protease inhibitors.

Peritoneal fluids from patients with diffuse peritonitis secondary to perforation of the appendix contained large quantities of collagenase and elastase. The enzymes, which existed in the form of complexes with plasma protease inhibitors, probably had been released from the granulocytes. The two enzymes had linked almost half of the alpha 1-antitrypsin and four fifths of the alpha 2-macroglobulin in the fluid. Evidence that regional defense against protease had failed was obtained by finding the C3 component of complement completely converted. Toxic peptides probably had been released. Recognition of plasma protease inhibitors as an important part of the regional defense against protease also suggested use for therapy. We lavaged the peritoneum postoperatively with fluid that did not contain plasma inhibitors but with volumes large enough to eliminate the accumulation of enzymes for the granulocyte.