THE INFLUENCE OF FATS ON THE MOTOR ACTIVITY OF THE PYLORIC SPHINCTER REGION AND ON THE PROCESS OF GASTRIC EVACUATION STUDIED BY THE BALLOON-WATER MANOMETER AND BY THE OPTICAL MANOMETER-FLUOROSCOPIC TECHNICS

Abstract

In studies made with the tandem balloon method the introduction of fats into the duodenum of fasting dogs inhibited the motility of the pyloric antrum, sphincter and duodenal bulb. A quantitative study of the pressure relations in the pyloric sphincter region combined with a visualization of motility and propulsion was obtained by the optical manometer-fluoroscopic technic. This method, showed that cream in the duodenum inhibited the pyloric region and further proved that cream decreased or reversed the antral-bulbar basal and phasic pressure gradients. The action of cream was most pronounced in fasting animals, then in order of decreasing effectiveness, fasting animals with the stomach distended by a large balloon, fed animals, fed animals with duodenal drainage. Fats retarded gastric evacuation chiefly by decreasing antral propulsive peristalsis. Sphincter spasm was not involved, on the contrary, evacuation was retarded in spite of sphincter relaxation. The rate of gastric evacuation represents a balance between a, the augmenting effect produced by a distension of the antrum and body of the stomach by food, and b, the inhibitory influence produced by the presence of chyme in the intestine, acting in part through mechanical (nonspecific) influences and partly through chemical (specific) factors. In expts. involving duodenal drainage, factor b was largely eliminated, thus the evacuating mechanism of the stomach was released from an important fraction of the intestinal regulation and the evacuation rate was augmented.