Evaluation of the role of mast cells in the progression of acetic acid-induced colitis in mice

Background: Mast cells are widely distributed in the gastrointestinal mucosa. However, their role in the pathogenesis of inflammatory bowel disease remains unsettled. The aim of the present study is to clarify the relative importance of mast cells in the progression of acetic acid-induced colitis in mice. Methods: Mast cell-deficient W/W-nu and their normal littermate +/+ mice were given intrarectal administration of 5% acetic acid. The severity of colonic damage, the number of mast cells, and myeloperoxidase (MPO) activities in the colonic tissues were examined. Results: The severity of colonic damage Was comparable between W/W-nu and +/+ mice. In both groups of animals kinetic changes of the severity of the mucosal damage agreed well with that of MPO activities in the colonic mucosa. Pretreatment with a mast cell stabilizer, ketotifen, did not affect the severity of colitis in +/+ mice. Conclusions: These results discount, but do not disprove, the role of mast cells in the progression of acetic acid-induced colitis in mice.