Role of cholecystokinin in the regulation of liquid gastricemptying and gastric motility in humans: studies with the CCKantagonist loxiglumide

Background—Exogenous cholecystokinin (CCK)inhibits antral motility and slows gastric emptying (GE) but the effectof endogenous CCK on the gastric motor mechanisms responsible for GEremains unclear.
Methods—The effect of the CCK-A antagonistloxiglumide (LOX) on GE and motility was studied using magneticresonance imaging in six healthy volunteers after ingestion of 500 mlIntralipid 10% (550 kcal). Subjects were studied in the supineposition on two occasions during intravenous infusion of LOX(66 µmol/kg/h for 10 min followed by 22 µmol/kg/h) or placebo. GEwas determined every 15 minutes using transaxial abdominal scans andmotility was studied by means of 120 coronal scans, 1.2 seconds apart. For each coronal image the proximal and distal (antral) diameters weremeasured at a fixed point in the stomach to determine contraction frequency (ACF) and amplitude (AMP).
Results—GE was faster during LOX infusion thanplacebo (t_1/2 31 (22) versus 115 (67) minutes, p<0.03).There was little variation in the diameter of the proximal stomach witheither LOX or placebo. In the distal stomach marked contractileactivity was observed during LOX (ACF 2.9 (0.2) versus 1.5 (2.9) duringplacebo, p<0.01). AMP also increased during LOX compared with placebo(56 (22)% versus 27 (16)%, p<0.001).
Conclusion—The increases in antral motility arelikely to contribute to the acceleration of GE and suggest that CCK mayregulate GE by acting on the distal stomach although an effect on theproximal stomach cannot be excluded.

Keywords:loxiglumide; magnetic resonance imaging; gastricemptying; gastric motility; antral contraction