Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society
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Neurogastroenterol. Motil. · Sep 2009
Clinical TrialEffects of clonidine and sumatriptan on postprandial gastric volume response, antral contraction waves and emptying: an MRI study.
Gastric emptying (GE) may be driven by tonic contraction of the stomach ('pressure pump') or antral contraction waves (ACW) ('peristaltic pump'). The mechanism underlying GE was studied by contrasting the effects of clonidine (alpha(2)-adrenergic agonist) and sumatriptan (5-HT(1) agonist) on gastric function. Magnetic resonance imaging provided non-invasive assessment of gastric volume responses, ACW and GE in nine healthy volunteers. ⋯ Gastric emptying was delayed. There was a negative correlation between gastric relaxation and GE rate (r(2 )=49%, P < 0.001), whereas the association between ACW frequency and GE rate was inconsistent and weak (r2=15%, P = 0.05). These findings support the hypothesis that nutrient liquid emptying is primarily driven by the 'pressure pump' mechanism.