Effect of bethanechol and metoclopramide on upper gastrointestinal motility in the kitten

Gastroesophageal reflux (GER) during infancy is a disorder of unknown etiology which may be associated with abnormalities of upper gastrointestinal motor function. Bethanechol, a muscarinic agonist, and metoclopramide, a dopamine antagonist, have been utilized as pharmacologic agents in an attempt to improve upper gastrointestinal motility in this disorder. We have studied the effect of these agents on upper gastrointestinal motility in an infant model, the kitten. Bethanechol is found to greatly increase lower esophageal sphincter (LES) pressure and have no effect on esophageal peristaltic amplitude or gastric emptying of a liquid meal. Metoclopramide causes a small and nonsignificant increase in LES pressure, has no effect on esophageal peristalsis, and increases the rate of gastric emptying of a liquid meal. These results suggest that these two agents may have specific actions on the infant's upper gastrointestinal tract.