Inflammatory Mediator Regulates Diarrhea in Inflammatory Bowel Disease

With knowledge that in patients with inflammatory bowel disease (IBD) immune responses contribute to mucosal permeability and therefore diarrhea, but no complete understanding of the mechanisms that govern this response, Northwestern University Medical School researchers recently conducted a study in which they found that activation of the inflammatory mediator NK-×B results in diarrhea in patients with IBD.

The study results, published online ahead of in print for the January 2010 issue of the American Journal of Pathology, show that blocking expression of the inflammatory mediator in the cells lining the intestinal tract after immune activation was successful in inhibiting diarrhea, as well as protein changes in the cells, allowing for decreased leakiness between the cells.

The researchers, led by Dr. Terrence A Barrett, concluded “NK-×B activation opens paracellular spaces and promotes movement of fluid into bowel lumen. … Importantly, changes in permeability were associated with a net movement of water and solute into the bowel lumen. These data not only correlated with clinical signs of diarrhea but also help explain the initial fluid accumulation observed in previous studies.”