Erythrocyte glutathione peroxidase and superoxide dismutase activities in different stages of chronic renal failure.

Antioxidant enzyme activities, glutathione peroxidase (GSH-Px) and Cu, Zn superoxide dismutase (SOD-1), were investigated in erythrocytes of non-dialyzed patients with varying degrees of chronic renal failure (CRF), and of patients on regular hemodialysis treatment. The results obtained have shown that GSH-Px and SOD-1 activities were significantly higher in erythrocytes from non-dialyzed CRF patients than in corresponding age-matched healthy controls. Antioxidant enzyme activities increase with the progression of chronic renal insufficiency, and the more pronounced augmentation in GSH-Px and SOD-1 activities were found in erythrocytes from the end-stage renal patients (with Ccr less than 20 ml/min). The increase of GSH-Px and SOD-1 activities seen in non-dialyzed CRF patients were abolished in patients undergoing regular hemodialysis treatment. We propose that the increased GSH-Px and SOD-1 activities could be a protective mechanism for the cells due to the hyperproduction of free radicals in chronic renal failure. The lowering of red blood cell antioxidant activity in uremic patients on chronic dialysis may contribute to the increased oxidative damage in uremia and in the development of uremic complications.