Effects of Treadmill Exercise on Mitochondrial DNA Damage and Cardiomyocyte Telomerase Activity in Aging Model Rats Based on Classical Apoptosis Signaling Pathway

Abstract

In order to explore the effect of treadmill exercise on mitochondrial DNA damage and myocardial telomerase activity in aging model rats based on the classical apoptosis signaling pathway, a total of 36 clean-grade male SD rats are selected. After modeling, the rats are randomly divided into groups, namely, control and 3 times/w and 6 times/w exercise rats, with 12 rats in each group. After the rats of each group are modeled, the myocardial tissue and cells are collected, the apoptosis of myocardial cells is detected by TUNEL method, and the protein expressions of Bax and Bcl-2 in myocardial tissue are detected by western blotting. The mtDNA content of the control rats is the highest, which is significantly higher than that of the exercise group ( $P<0.05$ ); the expression of mtDNA content in the heart of the rats exercising 3 times/w is significantly higher than that of the rats exercising 6 times/w ( $P<0.05$ ); cardiomyocyte apoptosis AI value, Bcl-2, and Bax expressions of the control rats is the highest and significantly higher than those in the exercise group ( $P<0.05$ ); Bcl-2/Bax in the control rats is the lowest and is significantly lower than that in the exercise group ( $P<0.05$ ). The AI value, Bcl-2, and Bax expression of myocardial cell apoptosis in 3 times/w exercise rats are significantly higher than those in 6 times/w exercise rats ( $P<0.05$ ); Bcl-2/Bax of 3 times/w exercise rats is significantly lower than that in 6 times/w exercise rats ( $P<0.05$ ); by observing the rats that completed treadmill exercise, Akt2 protein of 3 times/w exercise rats and 6 times/w exercise rats is observed and analyzed. Compared with the control rats, the expressions of the two proteins are increased in 3 times/w exercise rats and 6 times/w exercise rats, and the upregulation in 6 times/w exercise rats is significantly increased and higher than that in 3 times/w exercise rats ( $P<0.05$ ). For aging rats, treadmill exercise can reduce the body Bcl-2 and Bax values, improve the mitochondrial DNA damage and myocardial cell telomerase activity in aging model rats, and slow down the aging process.