title: Influence of the 5-HT3 receptor antagonist ondansetron on gastric sensorimotor function and nutrient tolerance in healthy volunteers.
abstract: BACKGROUND
  Serotonin is believed to be involved in the regulation of the gastric accommodation reflex in man however which receptor subtype(s) are involved remains to be elucidated.
  
  
  METHODS
  Eleven healthy subjects (nine men, age 19-30) underwent a gastric barostat and a drinking test after treatment with either placebo or ondansetron (8 mg intravenously). During the barostat protocol an intragastric flaccid bag was stepwise distended (2 mmHg increments 2 min) to determine gastric compliance and sensitivity to distention. Subsequently, the pressure level was set at intra-abdominal pressure +2 mmHg while volume was followed before and after administration of a liquid meal (200 mL; 300 kcal). During the drink test volunteers drank at a rate of 15 mL min(-1) until maximal satiation. Results (mean ± SEM) were compared using t-tests and mixed model analysis.
  
  
  RESULTS
  Gastric compliance was not significantly altered by ondansetron (51.5 ± 5.6 vs 49.2 ± 5.2 mL mmHg(-1)), neither were the pressure thresholds for first perception or discomfort. Ondansetron treatment did not affect basal gastric tone (173 ± 14 vs 156 ± 12 mL), neither did it affect the amplitude of the meal-induced relaxation (160 ± 52 vs 131 ± 43 mL) or the maximum volume increase after the meal (264 ± 54 mL vs 234 ± 51 mL). During the drinking test the amount of liquid meal ingested at maximum satiation was significantly increased by ondansetron (784 ± 74 vs 907 ± 64 mL, P < 0.05).
  
  
  CONCLUSIONS
  These data suggest that 5-HT acting at 5-HT(3) receptors is not involved in the control of gastric sensorimotor function, but contributes to the regulation of hunger and satiation in man.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, University Hospital Gasthuisberg, University of Leuven, Leuven, Belgium.
authors.forename: P
authors.initials: P
authors.lastname: Janssen
authors.forename: R
authors.initials: R
authors.lastname: Vos
authors.forename: L
authors.initials: L
authors.lastname: Van Oudenhove
authors.forename: J
authors.initials: J
authors.lastname: Tack
mesh_terms: D000328:Adult; D000818:Animals; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004326:Drinking; D004435:Eating / Q000502:physiology*; D005215:Fasting; D005260:Female; D006801:Humans; D006815:Hunger / Q000187:drug effects; D008297:Male; D017294:Ondansetron / Q000494:pharmacology*; D010919:Placebos; D019518:Postprandial Period; D044406:Receptors, Serotonin, 5-HT3 / Q000378:metabolism*; D012527:Satiation / Q000187:drug effects; D012701:Serotonin / Q000378:metabolism; D012702:Serotonin Antagonists / Q000494:pharmacology*; D013270:Stomach / Q000033:anatomy & histology / Q000187:drug effects* / Q000502:physiology*; D055815:Young Adult
chemical_list: D010919:Placebos; D044406:Receptors, Serotonin, 5-HT3; D012702:Serotonin Antagonists; D012701:Serotonin; D017294:Ondansetron