Age-related oxidative damage in Long-Evans rat retina.

The effect of age on the endogenous production of reactive oxygen species, catalase activity and lipid peroxidation in isolated rod photoreceptor outer segment membranes of Long-Evans rat retina was investigated. In rod outer segment membranes from rats at 90 days of age, the generation of reactive oxygen species was 4.0-fold higher than in membranes obtained from 23 day old animals. On the other hand, catalase activity was significantly lower in membranes from 90 day old rats as compared to those from 45 and 23 day old animals. Membrane lipid peroxidation was 2.0-fold higher in rod outer segments from 90 day old rats as compared to those from 23 days old animals. An age-dependent increase in membrane microviscosity in rod outer segments was also observed indicating a decrease in membrane fluidity during aging. The results indicate that the intramural generation of reactive oxygen species and membrane lipid peroxidation increases with age in rod photoreceptor outer segments from Long-Evans rat retina.