Superoxide anion generation, erythrocytes superoxide dismutase activity, and lipid peroxidation during hemoperfusion and hemodialysis in chronic uremic patients

In 11 chronic uremic patients superoxide anion generation in whole blood, both without and with opsonized zymosan stimulation, was lower than that in 11 healthy controls, while erythrocyte superoxide dismutase (SOD-1) activity and erythrocyte and plasma malonyldialdehyde (MDA) concentrations were elevated. During hemoperfusion (HP) and hemodialysis (HD) superoxide anion generation transiently significantly increased. Changes in the erythrocyte SOD-1 activity and plasma and erythrocyte MDA concentrations during HP suggested that this procedure exerted beneficial effects on lipid peroxidation. On the other hand, during HD erythrocyte membrane lipid peroxidation seemed to be enhanced even further; this phenomenon took place mainly within the dialyzer and a decrease in the erythrocyte SOD-1 activity seemed to be one of the contributing factors. Results of in vitro experiments with cross-incubation of erythrocytes and blood plasma and incubation of whole blood with cuprophan membrane suggest existence of an SOD-1 activator in the uremic blood plasma, which is possibly eliminated during HD.