Increasing antidumping effect of intestinal pacing with motor-active agents

The aim was to determine whether cholecystokinin-octapeptide (CCK-OP), bethanechol Cl, or metoclopramide HCl would increase the antidumping effect of intestinal pacing in five dogs with truncal vagotomy and Roux gastrectomy. While recording electrical activity from the conscious animals, the amount of a 100-ml, 25% dextrose gastric instillate emptied in 20 min was determined during control tests, during tests with CCK-OP (500 ng/kg/hr), bethanechol (80 micrograms/kg/hr), or metoclopramide alone (600 micrograms/kg/hr) given intravenously or during tests using combinations of pacing and drugs. In other tests, intraluminal gastrointestinal pressure was measured during control and drug infusions. CCK-OP, which relaxed the proximal stomach, slowed emptying of the dextrose instillates (mean +/- SEM emptied, no pacing, no drug = 74 +/- 5 ml; CCK-OP alone = 34 +/- 5 ml; P less than 0.05). CCK-OP also enhanced the slowing effect produced by pacing (pacing alone = 41 +/- 7 ml; pacing plus CCK-OP = 19 +/- 8 ml; P less than 0.05). In contrast, bethanechol and metoclopramide, which did not alter proximal gastric motility, did not alter emptying or augment or diminish the effect of pacing. The conclusion was that the combination of pacing and CCK-OP slowed gastric emptying of the dextrose more than pacing alone and thus had a greater antidumping effect. In contrast, neither bethanechol nor metoclopramide enhanced the pacing effect.