Impaired fibrinolysis and increased protease levels in gastric and duodenal mucosa of patients with active duodenal ulcer

Cathepsin B and L (cysteine proteases), urokinase- and tissue-type plasminogen activators (serine proteases), and type-1 inhibitor are involved in gastric mucosal injury. We determined tissue protease levels in duodenal ulcer and their relationship to ulcer phase, bleeding tendency, Helicobacter pylori infection, and use of H2-blockers.