1.   We have examined the hypothesis that the release of tissue type plasminogen activator may play a prominent role in endothelin induced gastric mucosal injury.

2.   Briefly, the activity of tissue type plasminogen activator can be measured by adding Glu-plasminogen, chromogenic plasmin substrate and fibrin at neutral pH.

3.   In the presence of fibrin, tissue type plasminogen activator converts plasminogen to plasmin, which subsequently cleaves the chromogenic substrate.

4.   These results could suggest a prominent role of tissue type plasminogen activator in the pathogenesis of endothelin induced gastric mucosal damage.

5.   Carcinogenesis in the human colon is associated with a marked increase of urokinase type plasminogen activator and a decrease of tissue type plasminogen activator.

6.   Absolute quantities of tissue type plasminogen activator antigen in the samples were calculated from an eight point standard curve of tissue type plasminogen activator.

7.   Urokinase type plasminogen activator and tissue type plasminogen activator activities were measured by a spectrophotometric enzyme assay as described previously.

8.   Activator activities were expressed as mIU urokinase type plasminogen activator or tissue type plasminogen activator per mg protein.

9.   Urokinase type plasminogen activator and tissue type plasminogen activator in squamous oesophagus were significantly lower than in the stomach.