Surgical stress induces phospholipid degradation in the intestinal brush border membrane

Background. Surgical stress can lead to translocation of bacteria from the intestine into the systemic circulation The intestinal brush border membran e (BBM) plays an important role in defense against such invasion by luminal bacteria and endotoxin. Our earlier work has shown the development of oxid ative stress in the intestine after surgical stress and since the BBM is se nsitive to free radical attack, this study examined the effect of surgical stress on the structure and function of intestinal BBM. Methods. Intestinal BBM were isolated from control and after surgical stres s and compared for structural and functional alterations. Surgical stress w as also carried out following pretreatment with the xanthine oxidase inhibi tor allopurinol or the nitric oxide donor L-arginine, to study the protecti on offered by these compounds. Results. Surgical stress affected intestinal BBM structure as well as funct ion. A decrease in alkaline phosphatase activity and alpha -tocopherol cont ent, accompanied by an increase in lipid peroxidation, was seen. Surgical s tress induced phospholipid degradation with generation of arachidonic acid. Functional impairment with a decrease in glucose transport ability was als o seen. These changes are prevented by inhibition of xanthine oxidase by al lopurinol pretreatment but not by NO. Conclusion. Surgical stress in the small intestine causes structural and fu nctional alterations in the BBM: through oxidative stress. This damage coul d affect gut barrier integrity and generation of arachidonic acid might med iate distal organ dysfunction. (C) 2000 Academic Press.