In vivo studies with collagenase from Pseudomonas aeruginosa.

An extracellular protease from Pseudomonas aeruginosa having collagenase activity was assayed in vivo. The lethality of the enzyme for white female mice was determined by use of intravenous, intraperitoneal, intranasal, and subcutaneous routes, respectively. The collagenase exhibited the following 72-hr mean lethal dose values: intranasally, 55 collagenase units; intraperitoneally, 148 collagenase units; and intravenously, 288 collagenase units. In the concentrations tested, no lethality was obtained when the subcutaneous route was employed. Gross and microscopic studies revealed that the collagenase was capable of eliciting a variety of tissue responses in mice depending upon its route of administration. Intranasal instillation resulted in confluent pulmonary hemorrhage, whereas intraperitoneal injections resulted in severe abdominal hemorrhage with foci on the intestinal serosa. Intravenous injections elicited abdominal hemorrhage and petechial hemorrhage with focal necrosis of the lungs, whereas subcutaneous injections resulted in necrotic, ulcerating lesions.