THE EFFECT OF HYDROCHLORIC ACID ON THE PYLORIC SPHINCTER, THE ADJACENT PORTIONS OF THE DIGESTIVE TRACT AND ON THE PROCESS OF GASTRIC EVACUATION

Abstract

The results obtained by direct observational methods (tandem balloon-water manometer and fuoroscopic-optical manometer technics) show that HCl in the stomach exerts little or no physiological action on the motor activities and the pressure changes in the pyloric sphincter region or on the process of gastric evacuation. HCl in the duodenum is moderately effective in suppressing the motor activity of the pyloric antrum and thus retards gastric evacuation. The pyloric sphincter and the upper duodenum are also inhibited, but this is of slight importance in the evacuation process. However, some duodenal re-gugitation may result from the more complete inhibition of the antrum than of the duodenal bulb and the resulting reversal of the antral-bulbar pressure gradient. Acid in the duodenum may produce a preliminary augmentation of motility in the sphincter region, but according to this investigation, it is of minor importance since it is rare, transient and moderate in degree.