ABSTRACT
Objective:To study the effect of exercise preconditioning on the expression of autophagy-related protein Beclin 1 and microtubule-associated protein 1 light chain 3 (LC3), and apoptosis after myocardial ischemia-reperfusion injury in rats, to explore the mechanism of myocardial protection by exercise preconditioning. Methods:A total of 36 male Sprague-Dawley rats were randomly divided into sham operation group, model group and exercise preconditioning group, with twelve rats in each group. The exercise preconditioning group received electric treadmill training for four weeks before modeling. The model of myocardial ischemia-reperfusion was made by ligation of the left anterior descending coronary artery 30 minutes and reperfusion. One hour after reperfusion, the expression of Beclin 1 and LC3 protein in myocardium was detected by Western blotting, and apoptosis of myocardial cells was observed by TUNEL staining, then the apoptotic index was calculated. Results:Compared with the model group, the level of LC3-I protein in the myocardial ischemic area increased, the levels of Beclin 1 and LC3-II decreased, the ratio of LC3-II/LC3-I decreased (P < 0.05); and the apoptotic index decreased in the preconditioning group (P < 0.05). Conclusion:Exercise preconditioning could up-regulate LC3-I in ischemic area, down-regulate the expression of Beclin 1 and LC3-II, and inhibit cardiomyocyte apoptosis after ischemia-reperfusion.