Cholinergic effects on human gastric motility
- aGastroenterology Section, Department of Medicine, Temple University Hospital, Philadelphia, Pennsylvania, USA, bNuclear Medicine Section, Department of Diagnostic Imaging, Temple University Hospital, Philadelphia, Pennsylvania, USA
- Dr H P Parkman, Gastroenterology Section, Department of Medicine, Parkinson Pavilion, 8th Floor, Temple University School of Medicine, 3401 North Broad Street, Philadelphia, PA 19140, USA.
- Accepted 9 March 1999
BACKGROUND Cholinergic regulation of chronotropic (frequency) and inotropic (force) aspects of antral contractility and how these impact on gastric emptying are not well delineated.
AIMS To determine the effects of cholinergic stimulation and inhibition on myoelectric, contractile, and emptying parameters of gastric motility.
METHODS Ten normal subjects underwent three studies each, using simultaneous electrogastrography (EGG), antroduodenal manometry, and gastric emptying with dynamic antral scintigraphy (DAS). After 30 minutes of baseline fasting manometry and EGG, subjects received saline intravenously, atropine (0.6 mg then 0.25 mg/hour intravenously), or bethanechol (5 mg subcutaneously). This was followed by another 30 minutes’ recording and by three hours of postprandial recording after ingestion of a technetium-99m labelled solid meal.
RESULTS During fasting, atropine decreased, whereas bethanechol increased, the antral manometric motility index and EGG power. Postprandially, atropine decreased the amplitude of antral contractions by DAS, decreased the postprandial antral manometric motility index, and slowed gastric emptying. Atropine caused a slight increase in postprandial frequency of antral contractions by DAS and gastric myoelectrical activity by EGG. Bethanechol slightly increased the amplitude, but slightly decreased the frequency of antral contractions by DAS and decreased the frequency of gastric myoelectrical activity by EGG, with no significant increase in the motility index or gastric emptying.
CONCLUSIONS Cholinergic antagonism with atropine reduces antral contractility and slows gastric emptying. Cholinergic stimulation with bethanechol increases antral contractility, but decreases the frequency of antral contractions, without altering the antral motility index or gastric emptying.
- Abbreviations used in this paper:
- antroduodenal manometry
- dynamic antral scintigraphy
- fast Fourier transform
- gastric emptying
- left anterior oblique
- motility index