The long time aerobic training effect on the mitochondrial DNA content and the activity of mitochondrial respiratory chain complexes in aging rats

Objective: To study long time aerobic training effect on mitochondrial DNA (mtDNA) content and activities of mitochondrial respiratory chain complexes in the myocardium and brain tissues of aged rats. Method: Forty-five rats were randomly divided into three groups Group A(n=15)younger rats did not received training; Group B (n=15) old rats did not received training; Group C (n=15) old rats received gradually training for 90 days, the mtDNA content were determined by methods of Yan etc, the activity of mitochondrial respiratory chain complexes in myocardium and brain tissues were determined by methods of Wu etc. Result: The mitochondrial DNA content in myocardium and brain tissues significantly increased (P<0.01) and the activity of mitochondrial respiratory chain complexes in myocardium and brain tissues significantly decreased (P<0.05-0.01) in the aging control group as compared with those in the young group. The mitochondrial DNA content in myocardium significantly decreased (P< 0.05), while there was no significant difference in brain. The activity of mitochondrial respiratory chain complexes in myocardium and brain tissues significantly increased(P<0.05-0.01) in the aging training group as compared with those in the aging control group. Conclusion: the long time aerobic training could decline the mitochondrial DNA content and increase the activity of mitochondrial respiratory chain complexes in myocardium and brain tissues in aging rats.