RESUMO
PURPOSE: To investigate the oxidative status of the aqueous humor of patients with pseudoexfoliation (PEX) syndrome. METHODS: Aqueous humor samples obtained during cataract surgery of patients with PEX syndrome and normal age-matched control subjects were examined for changes in the levels of glutathione (GSH), glutathione disulfide (GSSG), and TBA reactive species (TBARS), products of lipid peroxidation. GSH, GSSG, and TBARS were determined by specific fluorescent assays. RESULTS: Compared to normal controls, PEX syndrome aqueous humor samples showed a decrease of up to 28% of GSH concentration, and GSSG was increased up to 23%. The ratio of GSH/GSSG was 1.7-fold decreased in PEX syndrome samples. TBARS levels were increased by 100% in the PEX aqueous humor samples as compared to the controls. CONCLUSIONS: High levels of GSSG and TBARS indicate high oxidative stress, as well as the decrease in the ratio of GSH/GSSG. Our findings suggest a role for oxidation stress in the pathogenesis and the progression of PEX syndrome.
Assuntos
Humor Aquoso/metabolismo , Síndrome de Exfoliação/metabolismo , Glutationa/metabolismo , Peróxidos Lipídicos/metabolismo , Idoso , Idoso de 80 Anos ou mais , Feminino , Dissulfeto de Glutationa/metabolismo , Humanos , Peroxidação de Lipídeos , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo , Estudos Prospectivos , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismoRESUMO
PURPOSE: To investigate the oxidative status in lens epithelial cells of patients with pseudoexfoliation (PEX) syndrome. METHODS: Lens capsule samples obtained during cataract surgery of patients with PEX syndrome and normal age-matched control subjects were examined for changes in the levels of glutathione (GSH), glutathione disulphide (GSSG), protein concentration, and lipid peroxidation. Concentrations of GSH, GSSG, lipid peroxidation, and protein concentration were determined by specific fluorescent assays. RESULTS: This study shows a 2.2- and 2.0-fold decrease in GSH and GSSG levels, respectively, in PEX lens epithelial lens compared with non-PEX lens epithelial cells, as well as a 2.5-fold increase in lipid peroxidation product malondialdehyde (MDA) levels. CONCLUSION: The increased MDA and decreased GSH levels indicate high oxidative stress. On the other hand, GSSG usually increases in cases of high-oxidative stress, but this is not always the case, as it may not always accumulate in cells. Our findings suggest a role for oxidative stress in the pathogenesis and the progression of PEX syndrome.