[Ph measurement in the stomach and duodenum through endoscopy]

The pH values were measured by means of a flexible glass-electrode through endoscope in the stomach and duodenum. The measuring instrument and technique are described. The luminal and juxtamucosal pH values were determined. The latter indicates the pH value prevailing on the epithelial surface of the viscid mucous layer. The gradient between the two values expresses the hydrogen-ion neutralizing capacity of the viscid mucus on the surface of the mucosa. Quantitative data on the first protective line of the gastric and duodenal mucous membrane may be obtained by measuring it. The pH values at different points of the stomach and duodenum were determined through endoscope in 24 patients with duodenal ulcer and in 15 controls. No significant difference was found between the two groups concerning the gastric luminal pH values, however the luminal pH of the duodenal bulb was significantly lower in patients with duodenal ulcer than that of the controls. In patients with duodenal ulcer the juxtamucosal pH value was significantly lower at several points in the stomach and in the duodenum too as compared to the controls. This refers to the insufficient neutralizing capacity of the viscid mucous layer. The pH measurement performed through endoscope furnishes in a simple way valuable clinical data, it is furthermore the first quantitative method which can be used routine-like for the examination of the barrier function of the viscid mucous surface in the stomach and duodenum of man.