The effects of free radicals on organisms and antioxidant defence systems in hemodialysis patients

Chronic renal failure accompanies with various complications which can be developed because of an increase in oxidant stress and/or a decrease in antioxidant activity. The final renal failure is recognized as the end point. From this point it on, becomes compulsory to use either replacement therapy, hemodialysis, peritoneo-dialysis or transplantation for patient?s survive. For the renal failure, hemodialysis is still the most commonly used method in the world. In this study, it was aimed to find out whether there is an increase in lipid peroxidation or not in hemodialysis patients with advanced chronic renal failure and to evaluate the antioxidant enzyme activities. In thirty-five CRF patients having hemodialysis therapy and in the control group of twenty-seven healthy people malondialdehyde (MDA) plasma level, which is an indicator of lipid peroxydation, the activity of superoxide dismutase (SOD; an indicator of the antioxidant defence system), catalase (CAT), glutathione peroxidase (GSH-Px) and serum total antioxidant status (TAS) was measured. It has been ascertained that in the CRF patient group, MDA and SOD levels was higher than that in the control group (p <0,001); in contrast, GSH-Px and CAT levels were statistically decreased when compared with the control group (p <0,001). Again, TAS was higher in the control group as compared to the pre-dialysis results; however the results were lower when compared to the post dialysis results. According to the correlation analysis, there has been a positive correlation between urea-creatinin values both before and after dialysis. However, no statistically significance was observed between urea and other parameters.