Effect of vitamin E and N-acetylcysteine on phosphatidylserine externalization and induction of coagulation by high-glucose-treated human erythrocytes.

This study examines the effect of high glucose levels on the markers of oxidative stress, phosphatidylserine (PS) externalization, and induction of coagulation by high-glucose-treated red blood cells (RBCs). Washed normal RBCs were suspended to 15% hematocrit in phosphate-buffered saline and incubated with different concentrations of glucose for 24 hours in a shaking water bath at 37 degrees C. This treatment caused depletion of vitamin E and accumulation of vitamin E-quinone and malondialdehyde ([MDA] an end product of lipid peroxidation), externalization of PS in the membrane bilayer, and induction of coagulation by RBCs. Pretreatment of RBCs with N-acetylcysteine (NAC) and vitamin E reduced membrane lipid peroxidation, PS externalization, and the tendency of high-glucose-treated RBCs to clot plasma. This study provides further evidence for the increased oxidative stress in RBCs exposed to high glucose levels. In addition, it suggests a role for membrane lipid peroxidation in the PS externalization in the membrane bilayer and in the induction of clotting by RBCs exposed to hyperglycemia. It also suggests that certain antioxidants can decrease cellular damage and restore certain cellular functions in diabetes.