Background/aims: As acid secretory activity fluctuates with the same rhythm as motor activity during the interdigestive period, we investigated the relationship between these two cyclic activities.
Material and methods: In a series of 9 normal subjects the interdigestive gastroduodenal motor activity and the intragastric pH were recorded after an overnight fasting by means of a manometric and pH-metric apparatus. Thirty minutes after the second phase III of the Migrating Motor Complex (MMC), omeprazole, a proton pump inhibitor, was administered intravenously at a dose of 20 mg.
Results: After omeprazole administration, a typical gastroduodenal phase III similar to the spontaneous one appeared before its expected occurrence. The amplitude and frequency of pressure waves of the period between the end of omeprazole administration and the beginning of phase III were not significantly different from those of the period preceding the spontaneous phase III, but were significantly different from those of a corresponding period starting 30 min after a spontaneous phase III. The intragastric pH showed a significant increase from the basal values before the beginning of gastric phase III and continued to increase up to the end of recording.
Conclusions: The fact that the block of gastric acid secretion is followed by the appearance of a typical gastroduodenal phase III suggests that the acid secretory activity may have some influence on motor activity of the gastroduodenal tract.