大鼠胃肠道不同部位Cajal间质细胞与慢传输型便秘的关系

摘要

目的 观察慢传输型便秘( slow transit constipation,STC)大鼠模型胃肠道Cajal间质细胞(interstitial cell of cajal,ICC)的分布特点与含量改变,全面评估ICC在STC发病机制中的作用.方法 24只健康Wistar大鼠随机分成便秘组和对照组,分别饲喂含复方苯乙哌啶的混悬液和生理盐水,每5d记录1次大鼠大便粒数、大便干质量及大鼠体质量.饲养90 d后停药1周,测定胃肠道传输功能并通过免疫组化的方法测定ICC的特异性标志物c-kit+细胞在胃窦、小肠、结肠的分布情况与含量变化.结果 便秘组日均粪便粒数少于对照组(P＜0.01),平均每粒粪便质量大于对照组(P＜0.05)；便秘组首粒黑便排出时间长于对照组(P＜0.05)；与对照组比较,便秘组胃窦部位c-kit+细胞数量无明显变化(P＞0.05).而c-kit+细胞在便秘组大鼠小肠、结肠的数目均少于对照组(P＜0.05).结论 在STC模型中,胃窦ICC变化不明显,小肠ICC数量有减少趋势,可能对STC有一定影响,结肠部位ICC数量明显减少,可能是慢传输型便秘大鼠的主要病理生理机制.%Objective To observe distribution characteristics and content change of Cajal interstitial cells in rat gastrointestinal tract of the model of slow transit constipation, and evaluate the roles of the interstitial cells of Cajal (ICC ) in slow transit constipation in rats. Methods Twenty-four healthy Wistar rats were randomly divided to control group and constipated group. In the constipated group, the rats were daily administered with diphenoxylate (8 mg/kg) to develop slow transit constipation, while the control rats were fed with normal saline. The number and the weight of fecal granule and the body weight of rats were recorded every 5 days for 90 days. Transit functions of gastrointestinal movement were examined by an activated charcoal suspension pushing test one week after stopping the administration of diphenoxylate. The distribution of ICC positive cells confirmed with symbolic c-kit + cells in stomach, small intestine and the colonic wall were observed by immunohistochemical methods. Results The daily number of fecal granule in the constipated group was significantly less than that in the control group (P<0.01). The mean weight of each fecal granule in the constipated group was significantly higher than that in the control group (P <0.05). The discharge time of the first granule of black faeces in the constipated group was significantly longer than that in the control group (P < 0. 05 ). Compared with the control group, there were no significant differences of ICC positive cells in the gastric antrum in the constipated group (P >0. 05). The number of c-kit+ cells in small intestine and the distal colonic wall in the constipated group was significantly reduced compared with the control group (P<0.05). Conclusion In the model of slow transit constipation, ICC number in the gastric antrum was not change significantly. Decreasing trend of ICC number in the small intestine may have some influence on the incidence of STC. The visible reduction of ICC number in the distal colon may be contributed to the pathogenesis of slow transit constipation in rats.