E-Cadherin Expression in Colonic Mucosa with and Without Fecal Stream

ABSTRACT

The tissue content of E-cadherin changes in inflammatory bowel diseases; however, similar changes have not yet been evaluated in diversion colitis. Objective: The aim of this study was to evaluate the tissue expression of E-cadherin in the mucosa of the colon in both segments with and without a fecal stream. Methods: Sixty Wistar rats were subjected to deviation of fecal stream by proximal colostomy in left colon and a distal mucosal fistula. Animals were divided into three experimental groups that were sacrificed 6, 12, and 18 weeks after surgery. In each experimental group, five animals underwent laparotomy without intestinal deviation (control subgroup). Colitis was diagnosed based on the presence of three independent histological parameters: reduction of the crypt length, neutrophil infiltration of the mucosa and submucosa, and epithelial erosion or ulceration. The E-cadherin expression was evaluated by immunohistochemistry and the tissue levels by computerized morphometry. The Mann–Whitney and Kruskal–Wallis test were used to compare the groups adopting a significance level of 5% (p < .05). Results: Segments without fecal stream showed a reduction in E-cadherin content when compared with segments with fecal stream. In the segments with a fecal stream, E-cadherin was expressed at the apical surface of colon glands, while segments without fecal stream showed a decrease in the amount of apical E-cadherin. The content of E-cadherin was maintained over the entire time of the intestinal exclusion. Conclusions: Diversion of the fecal stream decreases the expression of E-cadherin of the colon epithelium.

Keywords: :

• colon
• colitis
• colostomy
• cadherins
• cell adhesion molecules
• immunohistochemistry
• volatile fatty acids