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 membrane (BBM) plays an important role in defense against such invasion by luminal bacteria and endotoxin. Our earlier work has shown the development of oxidative stress in the intestine after surgical stress and since the BBM is sensitive 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 stress and compared for structural and functional alterations. Surgical stress was also carried out following pretreatment with the xanthine oxidase inhibitor allopurinol or the nitric oxide donor l-arginine, to study the protection offered by these compounds. RESULTS Surgical stress affected intestinal BBM structure as well as function. A decrease in alkaline phosphatase activity and alpha-tocopherol content, accompanied by an increase in lipid peroxidation, was seen. Surgical stress induced phospholipid degradation with generation of arachidonic acid. Functional impairment with a decrease in glucose transport ability was also seen. These changes are prevented by inhibition of xanthine oxidase by allopurinol pretreatment but not by NO. CONCLUSION Surgical stress in the small intestine causes structural and functional alterations in the BBM through oxidative stress. This damage could affect gut barrier integrity and generation of arachidonic acid might mediate distal organ dysfunction.