Age-Related Retinal Degeneration in Animal Models of Aging: Possible Involvement of Taurine Deficiency and Oxidative Stress

Abstract

There is strong evidence that the retina degenerates with age. Electroretinogram deficits and photoreceptor cell death and structural abnormalities have been observed in both animal and human studies of aging. The mechanism behind this phenomenon is a very interesting area for scientific and medical study. Current data support the link between retinal degeneration and increased oxidative stress. Taurine is a free amino acid found in high millimolar concentrations in the retina, and age-related deficiency in retinal levels of taurine may contribute to the retinal degeneration associated with age. Taurine acts as an antioxidant and taurine replenishment is known to alleviate oxidative stress in the retina. Thus taurine supplementation may be useful in the treatment of age-related retinal dysfunction.

Lipid Peroxidation Potential and Antioxidants in the Heart Tissue of .BETA.-Alanine- or Taurine-Treated Old Rats

“…In the current study, we found that both AA-and NADPH-induced lipid peroxidation as well as endogenous lipid peroxidation increased in heart homogenates of old rats as compared to young rats. On the other hand, some investigators have reported that taurine levels decreased in plasma and some tissues such as liver, brain and kidney with aging (15)(16)(17). However, no significant changes in taurine levels were detected in the heart or skletal muscles of old rats (15).…”

Vitamins Inhibit Oxidant-Induced Apoptosis of Corneal Endothelial Cells

“…We have investigated the effects of oxidative stress on murine corneal endothelial cells (MCECs) and the response of these cells to different antioxidant vitamins that have, by operating as radical scavengers, previously shown a beneficial action against free radical-induced injury in other ocular tissues such as the retina. 4 On the other hand, the ability of these vitamins to promote CEC survival in addition to their antioxidative ability has not yet been convincingly clarified. To answer this question, a novel in vitro setting was employed to explore possible survival-promoting effects of the administration of vitamins A, C, and E to MCECs in a model of iron-mediated lipid peroxidation.…”

Changes in growth factor expression in normal aging of the rat retina

“…Without the protective effects of PEDF, photoreceptor cells may have a difficult time surviving in the elderly retina. Work has been done to indicate that aging of the retina is associated with a decrease in photoreceptor numbers, as well as ERG wave amplitudes (Militante and Lombardini 2004). Furthermore, the synthesis and secretion of PEDF has been found to be more effective in young human retinoblastoma cells and decreases during aging (Marciniak, Butwicka et al 2006).…”