Alteration of interstitial cells of Cajal in the colon of slow transit constipation rats

Objective To investigate the alteration of interstitial cells of Cajal (ICC)in the colon of slow transit constipation rats and to detect the role of ICC in the slow transit constipation(STC). Methods Thirty-two healthy Wistar rats were randomly divided into control group and model group of slow transit constipation. The rats in model group received diphenoxylate daily by intragastric administration to develop the slow transit constipated model. 100 days later,intestinal transit functions were examined by activated charcoal pushing test.Meanwhile,the expression of ICC was detected by immunohistochemistry and the alteration was analyzed by the computer image analysis system. Results The movement of contents from the proximal to the distal colon and rectum in model rats was significantly slower than that in normal rats. In model rats, the time of discharge of the first black faeces was 686 ± 57 min, significantly longer than that in normal rats 608 ± 46 min(P 0.05). ICC in model rats was significantly reduced than that of normal rats. This reduction was more significant in the ICC between the inner and outer layers of the muscularis propria. Conclusion The reduction of ICC in the STC model rats suggests that ICC may play an important role in the pathogenesis of STC.