Inhibitor of plasminogen activator in human arterial wall. I. Histochemical study

An inhibitor of urokinase, human urinary plasminogen activator, was found in the media of human arteries using a histochemical method (fibrin slide sandwich technique). Arteriosclerotic lesions, especially atherosclerosis, apparently contained the urokinase inhibitor. The inhibitor did not alter plasmin activity. This inhibitor of urokinase may be involved in regulation of fibrinolysis in arterial wall and thus a significant role in atherogenesis.