急性低压低氧对狗餐后和红霉素所致胃肠收缩的影响

Effect of acute hypobaric hypoxia on gastrointestinal contractile activity induced by meal and erythromycin in dogs

目的 观察在低压舱中模拟不同高度是否影响狗餐后和红霉素所致的胃肠收缩活动 ,为阐明飞行因素对胃肠动力的影响提供理论依据。 方法 应用低顺应性毛细管水灌注消化道腔内测压系统记录清醒狗胃和十二指肠的收缩活动。在低压舱地面、模拟升至 30 0 0 m和 5 0 0 0 m高度分别记录狗进食和静脉注射红霉素所致胃肠收缩的变化。 结果 1在模拟 5 0 0 0 m高度状态 ,狗餐后胃窦和十二指肠收缩振幅、收缩频率和动力指数明显低于地面时 (P<0 .0 5 ,P<0 .0 1) ;2在 5 0 0 0 m高度时 ,静脉注射红霉素引起狗胃窦和十二指肠收缩时间、振幅和动力指数也明显降低 (P<0 .0 5 ,P<0 .0 1) ;3模拟 30 0 0 m高度则对狗胃肠收缩无明显影响 ;4在 5 0 0 0 m高度狗的摄食能力也明显降低。 结论 急性暴露于低压低氧抑制了狗餐后和红霉素所致的胃窦和十二指肠收缩 。

Objective To investigate whether or not gastrointestinal contractions induced by meal or erythromycin (EM) would be affected in conscious dogs at several simulated high altitudes in hypobaric chamber, and to provide theoretical evidence for explaining mechanism of effect of flight factors on gastrointestinal motility. Methods Gastrointestinal contractile activities resulted from meal or intravenous injection of erythromycin at ground, 3 000 m and 5 000 m of simulated altitudes respectively, were recorded using a low compliance capillary water perfusion manometric system. Results ① Postprandial contractile amplitude, frequency, and motility index in the canine gastric antrum and duodenum at 5 000 m altitude decreased significantly as compared with that at ground ( P<0.05, P <0.01). ②Amplitude, duration and motility index of contractions elicited by EM at 5 000 m altitude were also lower than that in control. ③Gastrointestinal contractions were not affected at 3 000 m altitude. ④ The food intake decreased significantly in dogs at 5 000 m altitude. Conclusion Acute exposure to hypobaric hypoxia at 5 000 m can inhibit gastrointestinal motility induced by meal and EM, which may account for the loss of appetite in dogs.