The myoelectrical and motor response of the antropyloroduodenal region to intraduodenal nutrient stimulation or
antral tachygastria represent useful models for, respectively, physiological and pathophysiological
gastric stasis to test the efficacy of prokinetic drugs. We evaluated the effects of an intravenous bolus of
cisapride (0.63 mg/kg) on the myoelectrical and motor response of the antropyloroduodenal region to an intraduodenal
triglyceride emulsion (10%
Intralipid, 0.5 ml/min) or
antral tachygastria in conscious dogs. Intraduodenal
lipid suppressed
antral motility (P < 0.05, compared to intraduodenal saline) and stimulated phasic pyloric contractions (P < 0.01, compared to intraduodenal saline), a motor pattern known to be associated with delayed gastric emptying. During intraduodenal
lipid stimulation
cisapride virtually abolished all isolated pyloric motor events (P < 0.05) and stimulated
antral and duodenal motility (P < 0.05 for both) and antropyloroduodenal coordination (65% versus 15%; P < 0.05).
Antral tachygastria was associated with a higher number of isolated pyloric motor events in the fasted state [0.8 (0.7-1.1) per minute versus 0.2 (0-0.3) per minute; P < 0.05], but not during intraduodenal
lipid stimulation [1.1 (0.9-1.7) per minute versus 1.2 (1.0-1.9) per minute; NS].
Cisapride decreased the number and duration of spontaneous episodes of
antral tachygastria during intraduodenal saline and
lipid infusion (P < 0.05 for both) and abolished the tachygastria-associated motor patterns.
Cisapride induced a 20% decrease in the
antral slow-wave frequency during intraduodenal saline and
lipid, irrespective of gastric pacemaker rhythm. We conclude that: (1)
cisapride overcomes feedback from small intestinal
lipid receptors on myoelectrical and motor activities of the antropyloroduodenal region and decreases
antral slow-wave frequency, and (2)
cisapride inhibits
antral tachygastria and tachygastria-associated motor patterns. These effects may contribute to the effective gastrokinetic properties of
cisapride in physiological and certain forms of pathophysiological
gastric stasis.