Lipid peroxidation abnormalities in hemodialyzed patients.

In order to test the existence of a possible oxidative damage during hemodialysis, plasma conjugated dienes (CD), plasma and red blood cell (RBC) thiobarbituric acid (TBA) reactants were investigated in 25 patients receiving regular dialysis treatment (RDT). The RBC TBA reactant concentration was significantly increased in RDT patients in comparison with healthy subjects. The extracellular antioxidant systems were evaluated by the assay of plasma antioxidant activity, plasma tocopherol, urate, transferrin, haptoglobin and ceruloplasmin levels. Except urate and transferrin, none of these parameters were different between the two groups. On the other hand, in RDT patients, RBC superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities were significantly lower than in healthy subjects. There was an inverse correlation between decreased RBC GPX and RBC TBA reactant concentration. These results show in RDT patients the existence of an oxidizing stress, mainly intracellular, which could be due, in part, to a decrease in SOD and GPX activities.