Caloric restriction retards age-related changes in rat retina.

The neural retina of mammals consists of light sensitive photoreceptors and connecting neural cells that receive and send visual signal to the brain. Dietary caloric restriction (CR) is the only experimental intervention that can reliably retard the age-related degeneration of the retina in a normal mammalian model. Here, we studied the effect of CR on various biochemical parameters in the retina of male Brown Norway rats at different ages. We found that CR slowed the age-dependent protein insolubilization, blunted the declines in the total soluble thiols, and reduced glutathione and ascorbic acid levels in neural retina. We also observed that CR retarded the age-related decline in the levels of taurine, a vital amino acid in neural retina. These data are the first to implicate that CR may retard the age-related degeneration of retina by attenuating the oxidative stress and/or by sustaining the pool of protective factors in the neural retina.