Comparison of lifelong and late life exercise on oxidative stress in the cerebellum

Abstract

Aging was associated with increased oxidation of DNA, RNA, and lipids in the cerebellum of male rats. DNA and lipid oxidation was reduced by lifelong (94 weeks) voluntary exercise on a running wheel. A reduction in cerebellar lipid oxidation, but not RNA or DNA oxidation, was observed following 3 months of moderate exercise or dietary supplementation of vitamin E, initiated at 18 months of age. The level of lipid oxidation correlated with measures of forelimb grip strength. The results indicate that lifelong exercise attenuates multiple molecular markers of age-related oxidative damage in the cerebellum. In addition, modest exercise initiated late in life can have a beneficial effect on lipid oxidation and motor function.

Figure 1

Measures of cerebellar oxidative damage associated with aging and lifelong exercise. a) Body weight at the time of sacrifice. b) DNA oxidation was decreased in animals in the exercise group (CR-Run) and young (Yng) animals relative to aged ad libitum (Ad Lib) fed animals. c) An age-related increase in RNA oxidation was observed for Ad Lib rats. The distribution of 8-hydroxyguanosine–positive cells in the cerebellum of aged (d) young (e) rats. Bar = 200 μm. f) An age-related increase in lipid peroxidation was attenuated by lifelong exercise. For this and subsequent figures, bars represent the mean + SEM. Asterisk indicates significant (<0.05) difference relative to Ad Lib animals.

Figure 2

Influence of 3 mo exercise on markers of oxidative damage. a) Body weight at the time of sacrifice. No effect of treatment conditions was observed for (b) DNA and (c) RNA oxidation. d) Reduced lipid oxidation was observed in animals conditioned to run for food (Con-Run) and rats that exercised under mild caloric restriction (CR-Run) relative to Al Lib rats. e) Average weekly distance covered over the 3 mo period for animals with access to a running wheel. f) Relationship between MDA levels and the average weekly distance covered over the 3 mo period. The line is the best fit logarithmic function. Asterisk indicates significant (<0.05) difference relative to Ad Lib animals. † indicates significant (<0.05) difference relative to Ad Lib-Run animals. Pound sign indicates a significant (<0.05) difference between Con-Run and CR-Run groups.

Figure 3

Comparison of the influence of dietary supplementation with vitamin E for three month period (open bars) relative to a control diet (filled bars). Vitamin E supplementation was associated with a) reduced lipid peroxidation in the absence of an effect on b) DNA oxidation and c) RNA oxidation. d) Relationship between grip strength and MDA levels. Open circles represent animals with dietary supplementation of vitamin E.