ABSTRACT
Endogenous oxygen radical scavengers such as glutathione peroxidase (GSH-Px), catalase (CAT), glutathione and vitamin E are powerful regulatory systems against free radical toxicity. These oxidative injuries are increased in patients with chronic renal failure leading to various abnormalities including anemia. In this study, activities of GSH-Px, CAT, glutathione and vitamin E were measured in the erythrocytes of 54 chronic renal failure patients compared with 32 healthy controls. GSH-Px activities were lower significantly from controls (20.5 +/- 6.79 vs 28.3 +/- 9.0 u/gHb, p < 0.001). Erythrocytes CAT (6.52 +/- 2.3 vs 7.54 +/- 1.9 u/gHb, p < 0.05), glutathione (63.59 +/- 20.2 vs 75.1 +/- 6.3 mg/dl, p < 0.05) vit. E (2.23 +/- 0.53 vs 3.38 +/- 0.44 g/ml RBC, p < 0.001) were also lower in the patients group. Plasma malondialdehyde (MDA) known as lipid peroxidation product was higher significantly than controls (p < 0.001). Abnormal erythrocyte osmotic fragility test, expressed by glycerol lysis time (GLT50) was found in the patients group (p < 0.001) and correlated significantly with RBC vitamin E. Results demonstrated defects in erythrocytes enzymatic antioxidant defense mechanism in chronic renal failure patients. To improve antioxidant systems seems to be promising in preventing hemolysis and anemia in these patients.