LACK OF CRUCIAL ROLE OF MAST-CELLS IN PATHOGENESIS OF EXPERIMENTAL COLITIS IN MICE

Mast cell alterations have been implicated in the pathogenesis of chro nic ulcerative colitis (UC). We studied the effect of mast cell defici ency on the severity of inflammation in a murine model of colitis. Col itis was induced in mice using dextran sodium sulfate (DSS). Mast-cell -deficient mice (WBB6F(1)/J-W/W-v; N = 17) and normal littermates (WBB 6F(1)/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 wer e sacrificed at the end of the protocol. Segments of proximal, mid- an d distal colon of each animal were processed for histopathological exa mination. Mortality and morbidity (diarrhea and weight loss) for each group were assessed. There was no significant difference between the t wo groups in either their clinical parameters (mortality and morbidity ) or the severity of colitis as graded histopathologically. Our findin gs suggest that mast cells are not crucial for the development of DSS- induced colitis.