Interdigestive Gastroduodenal Motility in Patients with Active and Inactive Duodenal Ulcer Disease

Abstract

The interdigestive gastroduodenal motility was studied by means of a manometric probe in 6 patients with active duodenal ulcer and acid hypersecretion, in 6 patients with ulcer disease in remission (inactive) and normosecretion and in 8 healthy subjects with normosecretion. After a basal recording period sufficient to record at least two activity fronts of the migrating motor complex (MMC), an intraluminal infusion of isotonic NaHCO₃ was carried out for 180 min in patients with active duodenal ulcer, whereas in patients with ulcer in remission an HCl solution was infused for 180 min. Patients with active duodenal ulcer showed a basal motility with a longer than normal MMC cycle and a shorter than normal activity front, while patients with ulcer in remission showed a cyclic motor activity not significantly different from that of normal subjects. The NaHCO₃ infusion in patients with active ulcer restored a near-normal motility, whereas the HCl infusion in patients with ulcer in remission induced a motility similar to that of patients with active ulcer. These data indicate that the increase in gastric acid secretion is responsible for the decrease in frequency and duration of MMC activity fronts, which have the function of cyclically clearing the gastroduodenal lumen. Consequently, acid and bacteria may remain a longer than normal time in contact with the gastroduodenal mucosa, which, in this manner, may be greatly exposed to the risk of peptic lesions.

Effect of gastric acid suppressants on human gastric motility

“…It has been proposed that the regularity of the MMC may be governed by duodenal acidity; an alkaline duodenal pH is important for initiation of gastric phase III complexes 33. The short duration of fasting recording performed in this study (30 minutes) is a potential limitation; however, inhibition of gastric acid secretion has been observed to cause an increase in fasting gastric phase III activity in other studies with ranitidine34 and omeprazole35with more prolonged recording times. Conversely, increased gastric acid secretion has been associated with a decreased occurrence of MMCs 36…”

Interdigestive antroduodenal motility and gastric acid secretion

“…Intraluminal pH seems to be involved in regulating interdigestive antroduodenal motility 11 , . 12 , 14 , 16 During phases I and II of the MMC duodenal pH is always in the neutral or alkaline range. Only during phase II does the duodenal pH fluctuate irregularly between 2 and 7 11 , .…”

“… 12 Duodenal acidification inhibits gastric motility, increases irregular motor activity in the proximal duodenum and may even induce duodenal phase III‐like complexes 12 , . 13 In patients with active duodenal ulcer disease, 14 –16 and in healthy subjects with pharmacologically induced gastric hypersecretion, 14 antral motility is reduced and MMC cycle length is increased because of prolonged duodenal phase II activity. These inhibitory effects of excessive gastric acid on antroduodenal motility are reversed during gastric acid suppression using H 2 ‐receptor antagonists or by intragastric infusion of bicarbonate 15 , .…”

“… 13 Excessive gastric acid secretion increases MMC cycle length because of prolonged phase II activity, 11 , 14 an effect which can be reversed by acid suppression using H 2 ‐receptor antagonists 15 . Most of these studies have been performed in patients with upper gastrointestinal disorders, such as active duodenal ulcer disease 14 –16 . Little is known of the effect of acute acid inhibition on interdigestive gastrointestinal motility in healthy subjects.…”

Effect of gastrin on proximal gastric motor function in humans

“…From these results we can conclude that duodenal acidification causes relaxation of the proximal stomach. Previous studies in humans have shown the importance of duodenal pH in the regulation of interdigestive gastrointestinal motility 22 –28 . Duodenal acidification inhibits gastric activity by decreasing the antral phase III occurrence rate, while alkalization of the duodenum increases antral phase III occurrence rate 22 .…”