FREQUENCY OF GASTRIC PACESETTER POTENTIAL DEPENDS ON VOLUME AND SITE OF DISTENSION

Little is known about the response of the frequency of gastric paceset ter potential (PP) to luminal distension. When volume distension occur s as a result of a meal, gastric emptying may play an important role, since the site of distension shifts as the meal is displaced from the stomach to the small bowel. In this study, using dogs equipped with du odenal fistulas and serosal electrodes on the antrum, we compared the frequency of gastric PP during the course of gastric emptying while is olating the volume distension to either the stomach or the small bowel . We found that 1) the frequency of gastric PP decreased linearly with greater initial meal volume when volume distension was isolated to ei ther the stomach [P < 0.05, analysis of variance (ANOVA)] or small bow el (P < 0.01, ANOVA), and 2) the frequency of gastric PP decreased lin early with increased volume remaining in the stomach or increased volu me entering the small intestine. We conclude that the frequency of gas tric PP depends on volume and site of distension.