Histamine and tissue fibrinolytic activity in duodenal ulcer disease.

Patients with duodenal ulcer have lower gastroduodenal mucosal histamine and a reduced tissue fibrinolysis at the ulcer edge. In the duodenal mucosa fibrinolysis is regulated by the tissue-type and urokinase-type plasminogen activators; and inhibitors type 1 and type 2. Trends across ordered groups leading from mucosa of nonulcer control subjects, "normal" mucosa of ulcer patients, to ulcer edge were found in tissue-type plasminogen activator concentration, histamine concentration, and histamine methyltransferase activity. Concentrations of tissue-type activator, inhibitor type 1, and histamine were significantly lower at ulcer edge than at normal. An inverse correlation was found between histamine methyltransferase and plasminogen activator activities, methyltransferase and tissue-type activator, and methyltransferase and histamine. These results support the hypothesis that in active ulceration, reduction in tissue fibrinolytic activity is closely associated with enhanced release and metabolism of histamine.