Abstract:

Objective To observe the effects of changes of interstitial cells of Cajal from mice with post-infection irritable bowel syndrome (PI-IBS) on the intestinal motility and visceral sensitivity. Methods Thirty four female C57BL/6 mice were randomly divided into the model group (n=17) and control group (n=17). Mice of the model group were intragastricly injected by normal saline of 0.2 mL with 400 larvae of trichina. Mice of the control group were intragastricly injected by normal saline of the same volume. Pathological examinations were conducted for tissues of terminal ileum and proximate colon 14, 28, and 56 d after infection. The abdominal withdrawal reflex (AWR) scores, intestine transportation time, fecal grain numbers for every 2 h, and Bristol scores were determined 56 d after infection. The expressions of c-kit protein and mRNA in interstitial cells of Cajal of different intestinal segments were detected by the immunohistochemical staining and RT-PCR. Results The intestinal inflammatory reaction of mice of the model group regressed completely 56 d after infection. Compared to the control group, the AWR scores of mice of the model group were significantly higher (P<0.01) and the intestine transportation time was significantly shorter (P<0.01). Grain numbers for every 2 h, wet weights, and Bristol scores of the model group were significantly higher than those of the control group (P<0.05). Results of the immunohistochemical staining and RTPCR showed that compared to the control group, the expressions of c-kit protein and mRNA in interstitial cells of Cajal of each intestinal segment of mice of the model group were significantly increased (P<0.05). Conclusion The changes of the interstitial cells of Cajal of mice with PI-IBS may be one of the mechanisms of intestinal motility disorders and visceral hypersensitivity.

Key words: post-infection irritable bowel syndrome, interstitial cells of Cajal, intestinal motility, visceral sensitivity