肠神经系统递质和Cajal间质细胞在大鼠慢传输型便秘中的作用

Roles of enteric nervous system neurotransmitters and interstitial cells of Cajal in the colon in slow transit constipation in rats

摘要:

目的：探讨肠神经系统递质一氧化氮（NO）、P物质（SP）、血管活性肠肽（VIP）和Cajal间质细胞（ICC）在慢传输型便秘中的作用。方法：32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普通水，每5 d记录1次大鼠大便粒数、大便干重及体重。饲养90 d后停药1周，测定肠道传输功能、结肠黏膜肠神经系统递质含量和ICC细胞的特异性标志物c-kit+细胞分布情况。结果：便秘组日均粪便粒数小于对照组，平均每粒粪便质量大于对照组，差异有非常显著性意义（P<0.01）；便秘组首粒黑便排出时间为430.2±132.1 min，长于对照组的337.2±74.7 min，差异有显著性意义(P<0.05)。远端结肠黏膜NO含量、SP水平、VIP阳性细胞分布在两组间差异无显著性意义，而c-kit+细胞在便秘组的数目少于对照组，差异有显著性意义（P<0.05）。结论：远端结肠黏膜ICC数量减少可能是慢传输型便秘大鼠的主要病理生理机制。［中国当代儿科杂志，2009，11（6）：481-485］

Abstract:

OBJECTIVE: To evaluate the roles of enteric nerous system neurotransmitters, nitric oxide (NO), substance P (SP) and vasoactive intestinal polypeptide (VIP), and interstitial cells of Cajal (ICC) in the colon in slow transit constipation in rats. METHODS: Thirty-two healthy Wistar rats were randomly assigned to control and constipated groups. 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 water. 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 intestinal movement were examined by an activated charcoal suspension pushing test one week after stopping the administration of diphenoxylate. The levels of NO and SP in the colonic mucosa were measured by nitrate reductase methods and ELISA respectively. The distribution of VIP and ICC positive cells confirmed with symbolic c-kit+ cells in 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<0.01). The discharge time of the first granule of black faeces in the constipated group (430.2±132.1 min) was significantly longer than that in the control group (337.2±74.7 min; P<0.05). There were no significant differences in NO and SP levels and the density of VIP positive cells in the distal colonic segment between the two groups. The number of c-kit+ cells in the distal colonic wall in the constipated group was significantly reduced compared with that in the control group (P<0.05). CONCLUSIONS: The reduction of ICC number in the distal colon may be contributed to the pathogenesis of slow transit constipation in rats.［Chin J Contemp Pediatr, 2009, 11 (6):481-485］