[Leukotriene B4 in gastritis and peptic ulcer].

To contribute to a better understanding of the role of leukotrienes in inflammatory conditions of the upper gastrointestinal tract, leukotriene B4 (LTB4) levels were measured by specific radioimmunoassay in extracts of mucosal biopsies from the stomach and duodenum of control subjects and of patients with gastritis, benign gastric ulcer and duodenal ulcer. The control mucosa contained measurable levels of LTB4. Levels were 20% higher in gastritis than in controls and the lowest levels were found in the patients with no bile reflux. LTB4 levels were more than 3 times higher in duodenal ulcer (p less than 0.025) than in controls, whereas gastric ulcer margins had very low levels. No clear relationship was found between LTB4 levels and the drugs used in treatment. While these data do not explain the role of LTB4, they suggest that LTB4 may be an important mediator of the inflammation accompanying or leading to development of duodenal ulcer.