Changes in colonic tissue levels of inflammatory mediators in a guinea-pig model of immune colitis

Abstract

An immune colitis based on a delayed-type hypersensitivity reaction was induced in dinitrochlorobenzene (DNCB)-sensitized guinea-pigs by intrarectal challenge with DNCB. A low challenge dose (0.25% DNCB) induced mild inflammatory changes in the distal colon and rectum characterized by goblet cell depletion. A higher challenge concentration (5% DNCB) resulted in severe colonic ulceration with crypt abscess formation. The inflammatory mediators, histamine, 5-hydroxytryptamine (5HT), glandular kallikrein and PGE₂ were measured in freeze-dried colonic mucosae. Histamine content was three times control (pp2 was significantly (p<0.05) increased at both challenge doses. The possible significance of these changes with respect to severity of inflammation and aetiology of colitis is discussed.