Increases vascular permeability caused by the trypsin-like enzymes purified from rat submandibular gland

The vascular permeability increasing effect of several trypsin-like enzymes purified from the rat submandibular gland was studied. The size of the lesion caused by an intradermal injection of small amounts of the enzymes in blued rabbits was used as the measure of the permeability increasing effect. Salivain and four isozymic forms of a kallikrein-like peptidase caused a very marked increase in the vascular permeability. A clearly weaker response was obtained with glandulain and Depot-Padutin®, and a very weak response with trypsin. These lesions as well as that caused by bradykinin could not be prevented by prometazine, as was the lesion caused by histamine. The response to the enzymes was lowered to about one half by prior injections of phenylbutazone. It was concluded that the enzymes effect the vascular permeability by liberating vasoactive kinins.