Mucosal histamine content and histamine secretion in Crohn's disease, ulcerative colitis and allergic enteropathy.

Histamine exhibits various biological effects in inflammatory and immunological reactions. To further define its potential role in allergic enteropathy and inflammatory bowel disease, both gut mucosal histamine levels and histamine release from endoscopic biopsy samples were measured. Tissue histamine content resulted from addition of the released amount of histamine and the remaining part of tissue histamine. The results demonstrate highly elevated mucosal histamine levels of the large intestine in allergic enteropathy. In inflammatory bowel disease histamine content and secretion were found to be significantly increased particularly in affected mucosa of Crohn's disease and ulcerative colitis than in unaffected tissue or in healthy controls. These findings give strong evidence that mast cell mediators like histamine play a role in the pathogenesis of these diseases. Mucosal histamine is thus concluded to contribute to the immuno-inflammatory reactions of the intestine found in these disease states and to reflect the degree of colonic inflammation in Crohn's disease and ulcerative colitis.