Localization and immunological characterization of plasminogen activators in human prostate tissue

In tissue sections of human hyperplastic as well as carcinomatous prostate glands fibrinolytic activity could be attributed to collecting ducts and vessel walls. Inhibition studies with antibodies directed against human urokinase (u-PA) or tissue plasminogen activator (t-PA) revealed the presence of a plasminogen activator completely inhibitable by anti-t-PA IgG in the vessel walls, while in collecting ducts the plasminogen activator activity was inhibited by anti-u-PA IgG to only 80% and by anti-t-PA IgG to about 20%. A mixture of anti-u-PA and anti-t-PA IgG was able to inhibit fibrinolytic activity in collecting ducts completely. In carcinomatous prostate glands total fibrinolytic activity was significantly higher, but localization and relative contribution of anti-u-PA-inhibitable and anti-t-PA-inhibitable plasminogen activators remained the same.