To explore the mechanism in which alcohol induces dyspepsia, the study was designed to record the contractile activities
in the gastric antrum and duodenum in conscious dogs, by using low compliance capillary water perfusion manometric system. Blood samples in various phases of
migrating motor complex(MMC) were drawn for measuring plasma motilin concentrations. The effect of
intragastric infusion of ethanol on interdigestive MMC and postprandial gastrointestinal contractions, and the change in plasma motilin were observed. The results showed: ①The duration , amplitude and motility index of phaseⅢ occurred after intragastric perfusion of 15% ethanol at later phaseⅡ significantly decreased as compared with control group(P<0.05 ). Intragastric infusion of 30% ethanol blocked the occurrence of MMC phaseⅢ. ②Plasma motilin level showed cyclical fluctuations in different phases of MMC, it reached a peak during phaseⅢ and was the lowest during phaseⅠ in control group. The peak of plasma motilin level was lower in phaseⅢ after infusion of 15% ethanol than that of spontaneous phaseⅢ(P<0.05), and absent after infusion of 30% ethanol. ③Intragastric infusion of 30% ethanol obviously attenuated postprandial gastrointestinal contractile activity (P<0.01). So it is concluded that ethanol inhibits MMC and postprandial contractions in canine gastric antrum and duodenum, and that decreasing release of plasma motilin may be partially involved in its actions, suggesting it account for the alcohol-induced indigestion in man.