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

Abstract

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. Endoscopic biopsies of antral and duodenal mucosa were obtained from 61 patients with active or healed duodenal ulcer and control subjects. Antigen concentrations were measured by ELISA. Significantly higher levels of cathepsins, urokinase-type plasminogen activator, type-1 inhibitor, and significantly lower levels of tissue-type plasminogen activator were found in active ulcers. Bleeders had the highest cathepsins and urokinase-type plasminogen activator levels. Higher levels of urokinase-type plasminogen activator, cathepsin B, and type-1 inhibitor were observed in Helicobacter pylori-positive patients. Our results suggest that impaired fibrinolysis (tissue-type plasminogen activator), intramucosal proteases (cathepsins), tissue remodeling, and angiogenesis (urokinase-type plasminogen activator and type-1 inhibitor) are involved in duodenal ulcer formation and healing.