NONSPECIF IC PROTEASE AND ELASTASE ACT IV IT IES IN RAT LEUKOCYTES 1

Abstract--Extracts were prepared from rat peritoneal leukocytes obtained 4 h after glycogen injection and assayed for proteolytic enzyme activities against various substrates. The substrates used included acid-denatured bovine hemo-globin, bovine serum albumin, a partially purified preparation of rat pulmonary basement membrane, bovine neck ligament elastin, and an artificial substrate with elastase specificity. A high level of activity was observed when hemoglobin was used as the substrate. The serum albumin and basement membrane prepa-ration were also readily hydrolyzed by the leukocyte xtract. In contrast, the native elastin and synthetic elastase substrate were much more resistant. Al-though the leukocyte xtract demonstrated little intrinsic elastase activity, when it was mixed with a commercial hog pancreatic elastase preparation, it greatly potentiated the elastolytic activity, suggesting the activation of a latent enzyme