AGE-RELATED OXIDATIVE DAMAGE IN LONG-EVANS RAT RETINA

The effect of age on the endogenous production of reactive oxygen spec ies, catalase activity and lipid peroxidation in isolated rod photorec eptor outer segment membranes of Long-Evans rat retina was investigate d. In rod outer segment membranes from rats at 90 days of age, the gen eration of reactive oxygen species was 4.0-fold higher than in membran es obtained from 23 day old animals. On the other hand, catalase activ ity was significantly lower in membranes from 90 day old rats as compa red to those from 45 and 23 day old animals. Membrane lipid peroxidati on was 2.0-fold higher in rod outer segments from 90 day old rats as c ompared to those from 23 days old animals. An age-dependent increase i n membrane microviscosity in rod outer segments was also observed indi cating a decrease in membrane fluidity during aging. The results indic ate that the intramural generation of reactive oxygen species and memb rane lipid peroxidation increases with age in rod photoreceptor outer segments from Long-Evans rat retina.