Efeito dual da suplementação de ácidos graxos polinsaturados de cadeia longa (ω-3) sobre a retina de camundongos albinos (SWISS) submetidos à exposição à luz de média intensidade.

Abstract

Retinal degenerations are the major causes of blindness in the world, and the Age-Related Macular Degeneration (AMD) is the most important. The AMD is a slow and progressive disease with multi-factorial causes. The oxidative stress caused by light exposure is the major risk factor for this disease. Although there is no cure, dietary supplementation with ω-3 long chain polyunsaturated fatty acids (ω-3 LCPUFAs) is indicated for reduction of disease progression. The purpose of our study is evaluate the effects of dietary supplementation with ω-3 LCPUFAs in albino mice (SWISS) subjected to medium intensity light exposure. The animals were fed with a diet enriched with ω-3 LCPUFAs and exposed to white light (3000LUX) for 12 hours, and then evaluated at periods of 0, 7, 14, 21, 30, 60 and 90 days after exposure. Mice fed with a commercial diet served as controls. The retinal morphology, outer nuclear layer thickness, Retinal Pigmented Epithelium (EPR) cell number, presence and activation of microglial cells, PEDF immunolocalization, presence of apoptotic cells and retina neovascularization. Our results indicated that immediately after light exposure, supplemented animals had attenuated lesions compared to the control group. However, in subsequent periods, supplemented groups showed lesions similar or even more pronounced as the control group. These results suggest that ω-3 LCPUFAs have a dual effect on the retina, exerting an initial neuroprotection, and then exhibiting a deleterious effect to the retina.