Establishment and evaluation of a model of acute colitis induced by dextran sodium sulfate in C57BL/6 mice / 医学研究生学报

ABSTRACT

Objective The expression and impaired function of ion channels might be one of the pathophysiological mecha -nisms responsible for diarrhea in inflammatory bowel disease ( IBD) .Proper animal model is the key to explore detailed pathophysiolog-ical process.The purpose of this study was to build a rat model of acute colitis induced by dextran sodium sulfate (DSS) in C57BL/6 mice and evaluate diarrhea-associated clinical , histological , pathological parameters and expressions of ion channel protein . Methods C57BL/6J mice of model group were treated with 4%DSS solution for 7 days to induce acute colitis.Mice body weight, stool moisture, stool consistency and the degree of hematochezia were recorded .The histopathological changes of mice colon specimens were observed visually and microcosmically, and the ion channel SLC26A3 protein was detected by Western Blot . Results All experimental mice survived.In the experiment, compared with control group , bloody diarrhea and weight lose occurred in model group , along with increased stool moisture ([73.30 ±8.31]% after experiment vs [44.32 ±6.42]% before experiment, P=0.004), and rapidly in-creased disease activity index (DAI) of acute colitis ([3.50 ±0.87] after experiment vs [1.0 ±0.00] before experiment, P=0.000).At the end of this experiment , compared with control group , the model group resulted in higher colonic damage score and pathological inflammation score (P=0.00, P=0.002), significantly shortened co-lon (P=0.00) and decreased expression of SLC26A3. Conclusion The intestinal mucosal injury and phenotypic features of 4%DSS-induced acute colitis are very similar to those of human ulcerative colitis .Impaired expression of intestinal ion transporter SLC26 A3 coexists with diarrhea in model group mice , and this model can support the research on mechanism of functional changes of ion channels in inflammatory diarrhea .