Intraluminal Pressure Waves of the Stomach in Dogs Studied by Endoradiosondes

Abstract

Summary The intraluminal pressure wave activity of the gastric antrum and corpus in dogs deprived of food was studied by an endoradiosonde technique. Low pressure waves (type I waves) of varying activity were recorded during each 15-minute period. Bursts of high pressure waves (type II waves) occurred at intervals of 1/2 to 2 hr. Often, antral and corporeal type II waves were not synchronized and were of unequal amplitudes. Sham feeding abolished the type II activity for 1 1/2 hr. without affecting the type I activity. The immediate effect of a slow flowing meal was inhibition of type II activity and, sometimes, an increase of type I activity. A characteristic pressure wave response, consisting of a heavy burst of type II activity in the antrum, was caused by insulin hypoglycemia and occurred during the period of blood sugar decline, whereas type I activity was unchanged under these conditions. Sham feeding abolished the type II waves for more than 1 hr. also in an antrum excluded from the gastrointestinal passage, demonstrating that vagal release of gastrin from the antrum after sham feeding is not caused by antral motor activity. Observations in dogs deprived of food suggest that antral type II waves per se do not constitute a stimulus to gastric acid secretion.