Alteration of Antioxidant Enzyme Gene Expression with Aging and Exercise in Fisher Rats

ABSTRACT

BACKGROUND: It has been reported that radical oxygen species(ROS) production increased drastically during ageing. This increase in ROS had negative effects on many age-related diseases. In this study, we investigated the effects of ageing and exercise on antioxidant gene expression in Fisher rats and the mechanism of chronic exercise on ROS generation related to ageing. METHODS: After a standard diet, young and old male Fischer rats were assigned to sedentary control groups(young control group YC, old control group OC) and exercise training groups(young exercised group YE, old exercised group OE). After a 12-week treadmill exercise training in the exercise training groups, antioxidant gene expre- ssion(catalase, glutathione peroxidase) in the liver and muscle was measured by RT-PCR(reverse transcription- polymerase chain reaction). RESULTS: Liver catalase mRNA expression was lower in the old group compared with that in the young group. However, this remained unchanged post-exercise. Liver glutathione peroxidase mRNA expression was not different between the young and old groups and remained unchanged in both these groups. The expression of catalase mRNA in the soleus muscle was significantly lower in the old control rats compared with that in the young rats. Exercise sig- nificantly increased catalase mRNA expression in the soleus in both the young and old rats. The expression of gluta- thione peroxidase mRNA in the soleus was lower in the old control rats than in the young. Exercise significantly increased glutathione peroxidase mRNA expression in both young and old rats. CONCLUSION: This study showed that chronic exercise could be an important contributor to the recovery in the decline of certain antioxidant gene expressions in both young and aged rats. Long-term exercise may posi- tively affect metabolic diseases by modulating antioxidant gene expression.