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

2.   The sandwich ELISA for urokinase type plasminogen activator was carried out according to Binnema et al.

3.   The amount of urokinase type plasminogen activator antigen in the samples was calculated from an eight point standard curve of urokinase type plasminogen activator.

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

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

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

7.   Oesophageal tissue was found to contain significantly less urokinase type plasminogen activator and tissue type plasminogen activator, both in antigen and activity, compared with stomach tissue.

8.   The concentrations of urokinase type plasminogen activator in the duodenum resemble the quantities found in normal stomach tissue biopsy specimens.

9.   In colon carcinomas urokinase type plasminogen activator is predominantly found in the inactive proenzyme form, which can be activated in the presence of plasmin.