POLARIZED CACO-2 CELLS - EFFECT OF REACTIVE OXYGEN METABOLITES ON ENTEROCYTE BARRIER FUNCTION

Reactive oxygen metabolites are implicated in gastrointestinal disease and enterocyte injury associated with ischemia-reperfusion, bacterial translocation, inflammatory bowel disease, and necrotizing enterocoli tis. The ileal-like, human colon carcinoma cell line, Caco-2, was used to investigate oxidative damage. After challenging Caco-2 cells with reactive oxygen metabolites, the permeability, viability, and energy c harge of Caco-2 cells were assessed. Permeability was determined by tr ansepithelial electrical potential and flux of small molecules. Viabil ity was determined by release of Cr-51. Cell energy was evaluated by d etermining adenylate energy charge. The source of reactive oxygen meta bolites, with the exception of menadione, did not affect viability of Caco-2 cells; cell permeability was increased. The increased varied wi th the source and location of the reactive oxygen metabolite. There wa s no change in energy charge. This study suggests that reactive oxygen metabolites could cause enterocyte damage and that the source of the reactive oxygen metabolite is an important variable in determining the extent of damage. Antioxidants might prevent injury.