Changes in blood antioxidants and several lipid peroxidation products in women with age-related macular degeneration

PURPOSE. The aim of this study was to evaluate the ferric reducing ability of plasma (FRAP), selected enzymatic and non-enzymatic components of the antioxidative system, and the intensity of peroxidative processes in the blood of patients with age-related macular degeneration (AMD). METHODS. In the peripheral blood, we evaluated FRAP; concentrations of vitamins C, A, and E, and of thiols. We assayed the activity of enzymatic components of the antioxidative system-superoxide dismutase, catalase, ceruloplasmin and the concentration of reduced glutathione as an indicator of glutathione peroxidase activity. In order to determine the intensity of lipid peroxidation, we measured the concentrations of malondialdehyde and hydroxyalkenales (MDA-HNA) and conjugated diens (CD). RESULTS. We found a significant increase in FRAP in patients with AMD compared with the control group. The average concentrations of vitamins A and C were low and vitamins E and GSH were significantly higher in AMD than in the control group. The activity of almost all the antioxidative enzymes was high. We found a significant increase in MDA-HNA but no difference in CD. CONCLUSIONS. The significantly higher concentration of lipid peroxidation products in patients with AMD indicates an important pathogenic role of oxido-reduction disturbance. The high FRAP concentration may be one of the protective mechanisms in oxidation stress. The adaptive increase of the antioxidant barrier mostly involves the enzymatic components.