Cr(VI) Induces Lipid Peroxidation, Protein Oxidation and Alters the Activities of Antioxidant Enzymes in Human Erythrocytes

摘要

The effect of potassium dichromate (K₂Cr₂O₇), a hexavalent chromium compound, on human erythrocytes was studied under in vitro conditions. Incubation of erythrocytes with different concentrations of K₂Cr₂O₇ resulted in marked hemolysis in a concentration-dependent manner. K₂Cr₂O₇ treatment also caused significant increase in protein oxidation, lipid peroxidation and decrease in total sulfhydryl content, indicating that it causes oxidative stress in human erythrocytes. However, there was no concomitant nitrosative stress as the nitric oxide levels in hemolysates from K₂Cr₂O₇-treated erythrocytes were lower than in control. Exposure of erythrocytes to K₂Cr₂O₇ decreased the activities of catalase, glutathione peroxidase, thioredoxin reductase, glucose-6-phosphate dehydrogenase, and glutathione reductase, whereas the activities of Cu–Zn superoxide dismutase and glutathione S-transferase were increased. These results show that K₂Cr₂O₇ induces oxidative stress and alters the antioxidant defense mechanism of human erythrocytes.