백서적출소장편 운동변화에 대한 Morphine과 Metoclopramide의 영향

Abstract

Many reports have shown that morphine produces profound effects on the gastointestinal motility that include changes in peristaltic activity, intramural pressure and sphincter tone. And recently, the effect of opiates on the gastrointestinal tract are complex and apparently involve both a peripheral and a central action, and have variety of animal species Also, the author has been reported that the stimulatory effect of metoclopramide on gstrointestinal tract is related to augment acetylcholine release partially. Therefore, the author investigated the peripheral cholinergic property of morphine as comparative with cholinergic action of metoclopramide in the isolated rat (normal and morphine-tolerant:20mg/kg i.p. for 7days) small intestine. The results obtained are summarized as follows: 1. Morphine(10^-8－10^-5M) decreased dose-dependently the motility of the normal isolated rat small intestine, but increased the tone of it. Metoclopramide (10^-8－10^-5M) increased the motility and tone of the isolated rat small intestine. 2. In the morphine-tolerant rat, morphine-induced contractile response of small intestine was less sensitive to morphine than that of the normal rat, and morphine(10^-8－10^-7M) produced inhibitory effect on the motility and tone of isolated rat small intestine. 3. Morphine-induced contractile response was inhibited by naloxone markedly, and metoclopramide-induced contractile response was inhibited by atropine pretreatment markedly. 4. Morphine or metoclopramide-induced contractile response was not affected markedly by dkbenamine(10^-8M), propranolol(10^-8M) and hexamethonium(10^-8M) in the normal isolated rat small intestine.