Mittal R K, Frank E B, Lange R C, McCallum R W
Dig Dis Sci. 1986 Sep;31(9):936-42. doi: 10.1007/BF01303214.
We studied the effect of morphine and naloxone on lower esophageal sphincter pressure, esophageal contraction amplitude, and gastric emptying of solids and liquids in ten normal healthy subjects. Morphine sulfate in a dose of 8 mg intravenous bolus significantly decreased sphincter pressure with a maximum fall of 22.8% of the basal tone. Naloxone, 5 mg intravenous bolus, resulted in a 20% increase in the baseline pressure. There was no change in the esophageal contraction amplitude, duration, or frequency of peristalsis with either morphine or naloxone. Gastric emptying was measured using a dual-isotope technique to simultaneously assess the emptying rates of both solid and liquid meal components. Morphine, 8 mg intravenous bolus, led to a significant inhibition (P less than 0.05) of the gastric emptying of both solids (99mTc sulfur colloid-labeled chicken liver) and liquids (111In DTPA-labeled water). Naloxone, 5 mg intravenous bolus, accelerated the gastric emptying of both solid and liquid components, but this did not achieve statistical significance. These observations suggest that: morphine's inhibitory effect on gastric emptying and lower esophageal sphincter pressure may contribute to its potent emetic properties; the human lower esophageal sphincter and stomach may have opiate receptors and further investigations should be addressed to determining if endogenous opiates play a role in the modulation of sphincter pressure and gastric emptying in humans.
我们研究了吗啡和纳洛酮对10名正常健康受试者的食管下括约肌压力、食管收缩幅度以及固体和液体胃排空的影响。静脉推注8毫克硫酸吗啡可显著降低括约肌压力，最大降幅为基础张力的22.8%。静脉推注5毫克纳洛酮可使基线压力升高20%。吗啡或纳洛酮对食管收缩幅度、持续时间或蠕动频率均无影响。采用双同位素技术测量胃排空，以同时评估固体和液体餐成分的排空率。静脉推注8毫克吗啡可显著抑制固体（99mTc硫胶体标记的鸡肝）和液体（111In DTPA标记的水）的胃排空（P<0.05）。静脉推注5毫克纳洛酮可加速固体和液体成分的胃排空，但未达到统计学意义。这些观察结果表明：吗啡对胃排空和食管下括约肌压力的抑制作用可能与其强烈的催吐特性有关；人类食管下括约肌和胃可能存在阿片受体，应进一步研究内源性阿片类物质是否在调节人类括约肌压力和胃排空方面发挥作用。
