Lack of crucial role of mast cells in pathogenesis of experimental colitis in mice

Mast cell alterations have been implicated in the pathogenesis of chronic ulcerative colitis (UC). We studied the effect of mast cell deficiency on the severity of inflammation in a murine model of colitis. Colitis was induced in mice using dextran sodium sulfate (DSS). Mast-cell-deficient mice (WBB6F₁/J-W/W^v;N=17) and normal littermates (WBB6F₁/J-+/+;N=17) were administered DSS 4% w/v for seven days, then water alone for one week, followed by 5% DSS for six days. Animals were sacrificed at the end of the protocol. Segments of proximal, mid-, and distal colon of each animal were processed for histopathological examination. Mortality and morbidity (diarrhea and weight loss) for each group were assessed. There was no significant difference between the two groups in either their clinical parameters (mortality and morbidity) or the severity of colitis as graded histopathologically. Our findings suggest that mast cells are not crucial for the development of DSS-induced colitis.