Abstract
Preparations of plasminogen, soluble in aqueous media, increased vascular permeability in guinea pig skin when activated by streptokinase or urokinase. The permeability-enhancing effect was inhibited by soybean trypsin inhibitor but not by triprolidine. Permeability-enhancing activity evolved when plasmin was incubated with fractions of plasma rich in prokinin. The experiments described suggest that plasmin exerts its permeability-increasing effect through the elaboration of kinins.