TY - JOUR
T1 - Oxygen free radical injury of IEC-18 small intestinal epithelial cell monolayers
AU - Ma, Thomas Y.
AU - Hollander, Daniel
AU - Freeman, Doug
AU - Nguyen, Thang
AU - Krugliak, Pavel
PY - 1991/6
Y1 - 1991/6
N2 - Oxygen radicals can cause endothelial and epithelial permeability changes and mucosal injury of the small intestine. There is no clear consensus concerning the relative injurious potential of individual oxygen radicals. In this study, the small intestinal cell line IEC-18 was used as an in vitro model to study the relative injurious effects of reactive oxygen metabolites. By introducing different combinations of oxygen metabolite-producing enzymes, xanthine oxidase, superoxide dismutase, and catalase, and an iron chelator, deferoxamine, to the fully confluent monolayers and to proliferating IEC-18 cells, the differential injurious effects of the oxygen metabolites O2-, H2O2, and OH- could be evaluated. The extent of cellular injury was assessed using [3H]thymidine uptake, 51Cr release, and morphological evaluations. Our results suggest that OH- produced as a by-product of O2- and H2O2 via the Haber-Weiss reaction was the most injurious oxygen species involved in cellular injury of IEC-18 monolayers induced by xanthine oxidase. O2- produced by xanthine oxidase appeared to be only minimally injurious, and H2O2 produced by xanthine oxidase and as a result of conversion of O2- by superoxide dismutase was moderately injurious. Superoxide dismutase and deferoxamine at appropriate concentrations were protective against xanthine/xanthine oxidase-induced monolayer injury. H2O2 added directly or produced indirectly by glucose oxidase was very injurious to the intestinal monolayers, and this injury was mitigated by catalase.
AB - Oxygen radicals can cause endothelial and epithelial permeability changes and mucosal injury of the small intestine. There is no clear consensus concerning the relative injurious potential of individual oxygen radicals. In this study, the small intestinal cell line IEC-18 was used as an in vitro model to study the relative injurious effects of reactive oxygen metabolites. By introducing different combinations of oxygen metabolite-producing enzymes, xanthine oxidase, superoxide dismutase, and catalase, and an iron chelator, deferoxamine, to the fully confluent monolayers and to proliferating IEC-18 cells, the differential injurious effects of the oxygen metabolites O2-, H2O2, and OH- could be evaluated. The extent of cellular injury was assessed using [3H]thymidine uptake, 51Cr release, and morphological evaluations. Our results suggest that OH- produced as a by-product of O2- and H2O2 via the Haber-Weiss reaction was the most injurious oxygen species involved in cellular injury of IEC-18 monolayers induced by xanthine oxidase. O2- produced by xanthine oxidase appeared to be only minimally injurious, and H2O2 produced by xanthine oxidase and as a result of conversion of O2- by superoxide dismutase was moderately injurious. Superoxide dismutase and deferoxamine at appropriate concentrations were protective against xanthine/xanthine oxidase-induced monolayer injury. H2O2 added directly or produced indirectly by glucose oxidase was very injurious to the intestinal monolayers, and this injury was mitigated by catalase.
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U2 - 10.1016/0016-5085(91)90650-A
DO - 10.1016/0016-5085(91)90650-A
M3 - Article
C2 - 1850372
AN - SCOPUS:0025832533
SN - 0016-5085
VL - 100
SP - 1533
EP - 1543
JO - Gastroenterology
JF - Gastroenterology
IS - 6
ER -