Comparative histochemical studies on fibrinolysis in whole organs and isolated tissue layers.

Using Todd's technique for the detection of plasminogen activator and Noordhoek Hegt and Brakman's method for inhibitors of fibrinolysis, rat tissues were studied, both in sections of whole organs and as separated tissue layers. Whole organ preparations showed less fibrinolytic activity and poorer localisation of inhibitor, because of a widespread diffusion of the inhibitor from tissue layers rich in inhibitor during the histochemical procedures. It is concluded that when using histochemical methods both agents are best studied in separated layers of the organ to avoid the masking effects of diffused inhibitor.