Disturbance in villous microcirculation in the rat small intestine in a model of inflammatory bowel disease: Role of hydrogen peroxide

Background: This study was conducted to quantify the effect of systemic Cat alase, a hydrogen peroxide scavenger, on villous microcirculation in the in flamed small intestine of the rat. Intestinal inflammation was induced with s.c. application of Indometacin. Methods: Intravital fluorescence microscopy and FITC-labeled erythrocytes w ere used to quantify erythrocyte velocity and arteriolar diameter in the ma in arteriole of the villi in the terminal ileum following i.v, application of Catalase in the inflamed intestine, and the blood flow was calculated. C ontrol groups were formed for Ringer's lactate, Catalase and Indometacin, r espectively. Results: We found that villous blood flow was significantly increased in th e in the inflamed intestine. Application of Catalase led to a significant d ecrease in villous perfusion, but had no effect in the control group. Hyper emia in the main arteriole was significantly reduced by H2O2-scavenger Cata lase, suggesting that endogenous H2O2 may be one of the mediators of hypere mia in the mucosa in this animal model of intestinal inflammation. Conclusions: Further studies are required to determine whether compounds th at inactivate hydrogen peroxide may be beneficial in the treatment of infla mmatory bowel disease in man.