Resumo

MIRANDA, M. et al. Oxidative stress in a model of experimental diabetic retinopathy: the utility of peroxinytrite scavengers. Arch Soc Esp Oftalmol [online]. 2006, vol.81, n.1, pp.27-32. ISSN 0365-6691.

Purpose: The retina is the neurosensorial tissue of the eye and is extremely rich in polyunsaturated lipid membranes. This feature makes it especially sensitive to oxygen and/or nitrogen activated species and lipid peroxidation. Several authors have postulated the importance of superoxide (O ₂ ^- ) and peroxynitrite production in the development of diabetic complications. In the present study, we have used two different antioxidants, ebselen and lutein, that present as a common feature their peroxynitrite scavenging capacity, to ameliorate the oxidative stress that exists in the retina in diabetic patients. Methods: Hyperglycemia was accomplished by the intraperitoneal injection of Alloxan in a mouse model of diabetic retinopathy. Malondialdehyde (MDA) and glutathione (GSH) concentrations in eye homogenates (without the lens) were determined. We also recorded serial electroretinograms (ERG) and measured latency and implicit times. Results: The MDA concentration increased and the GSH concentration decreased in the eyes of the diabetic animals. Treatment with ebselen and lutein restored the MDA and GSH concentrations to control values. Latency and implicit times were not affected by the diabetes. Conclusion: New studies are required to better understand the protective mechanism of ebselen and lutein in this model of experimental diabetic retinopathy.

Palavras-chave : Diabetes; mouse; ebselen; lutein; oxidative stress; electroretinogram; antioxidants; peroxynitrite.

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