Enhanced expression of neutrophil NADPH oxidase components in intestine ofrats after burn injury

We have evaluated the accumulation of neutrophils in the gut and their infi ltration into the intestinal extravascular spaces in rats subjected to a 25 % total body surface area scald burn. The accumulation of neutrophils was a ssessed via measurements of myeloperoxidase (MPO) activity in the intestina l homogenates, and the immunohistochemical localization of neutrophil NADPH oxidase component proteins (p47(phox) and p67(phox)) within the intestinal extravascular spaces determined neutrophil tissue infiltration. MPO measur ements demonstrated a 12- and 21-fold increase above the control value in t he intestinal tissue at day 1 and day 3 post-burn, respectively, suggesting that a substantial total tissue accumulation of neutrophils occurs in the gut after burn injury. The immunohistochemical staining procedures showed b oth a definitive presence of the neutrophil in the intestinal extravascular spaces and an enhanced immunoreactivity in neutrophils accumulating in int estine after burn injury. There was no evidence of either the presence of n eutrophils in the extravascular regions or any significant neutrophil immun oreactivity to NADPH oxidase component proteins in the intestines of sham c ontrol rats. These findings indicate that burn injury causes an enhanced mi gration of circulating neutrophils into the intestinal interstitial spaces and an upregulation of NADPH oxidase activity in the infiltrating neutrophi ls.