Abstract
Biopsy and autopsy specimens of testis ductus deferens, prostatic gland and seminal vesicles were examined histochemically for plasminogen activator activity. In all the organs studied the activator activity was found to be confined to small blood vessels, especially those situated in connective tissue. In the testis the activity was low. As for the ductus deferens, the activity was localized to small vessels surrounding it and possibly important for its nutrition. The plasminogen activator activity wa, found to be highest in the prostatic gland and seminal vesicles. The secretary epithelium of these glands exhibited no fibrinolytic activity. The high fibrino-lytic activity of semm therefore presumably derives from wine inactive precursor occurring in the secretory epithelitm not localizable by the histochemical method.