The contribution of small intestinal motor activity to nutrient absorption is poorly defined. A reduction in duodenal flow events after hyoscine butylbromide, despite no change in pressure waves, was associated with reduced secretion of the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), and a delay in glucose absorption. Aim: To investigate the effect of metoclopramide on duodenal motility and flow events, incretin hormone secretion, and glucose absorption. Methods: Eight healthy volunteers (7 male; age 29.8±4.6 yr; BMI 24.5±0.9 kg/m2) were studied twice in randomized order. A combined manometry and impedance catheter was used to measure pressure waves and flow events in the same region of the duodenum simultaneously. Metoclopramide (10 mg) or control was administered intravenously as a bolus, followed by an intraduodenal glucose infusion for 60 minutes (3 kcal/min) incorporating the 14C-labelled glucose analog 3-O-methylglucose (3-OMG). Results: Metoclopramide was associated with more duodenal pressure waves and propagated pressure sequences than control (P < 0.05 for both), during intraduodenal glucose infusion. However, the number of duodenal flow events, blood glucose concentration, and plasma 14C-3-OMG activity did not differ between the two study days. Metoclopramide was associated with increased plasma concentrations of GLP-1 (P < 0.05) and GIP (P = 0.07), but lower plasma insulin concentrations (P < 0.05). Conclusion: Metoclopramide was associated with increased frequency of duodenal pressure waves, but no change in duodenal flow events and glucose absorption. Furthermore, GLP-1 and GIP release increased with metoclopramide, but insulin release paradoxically decreased.
- Copyright © 2009, American Journal of Physiology- Gastrointestinal and Liver Physiology