Eight Weeks Of Aerobic And Intermittent Motion Of The Myocardial Infarction Rat Myocardial Infarct Size, The Role Of Blood Flow Dynamics And Cardiac Bax And Bcl-2 And Caspase-3 Expression

Objective:Ischemic heart disease can bring threats to human health; therefore, completely elucidating the pathogenesis and to seeking effective treatment, has been the focus of cardiovascular research in the field content. Studies have shown that exercise can protect the ischemic myocardium, improve cardiac function; aerobic exercise and interval training are both able to protect myocardial infarction; since the treatment effects on various diseases of interval training is superior to aerobic exercise, we wonder whether interval training is effective on the recovery of myocardial infarction. Effect of aerobic training and high-intensity interval training on infarct size and expression of myocardial Caspase-3, Bax and Bcl-2 was observed in our research, in order to provide more effective training methods and experimental basis for the treatment after myocardial infarction.methods:40 SD male rats (Medical college of Xi'an Jiaotong University), their weights ranging from 200-220g. Treat the rats with coronary artery ligation (ligation of heart anterior descending artery, two types of complete ligation and thoracotomy without ligation, that is to say, myocardial infarction and sham myocardial infarction), and the groups are as belows:1. Group of sham myocardial infarction (10).2. Group of myocardial infarction+quiet (10).3. Group of myocardial infarction+aerobic exercise (10).4. Group of myocardial infarction+high-intensity interval aerobic training (10).The rats were trained one week after the surgery as follows, according to the exercise program designed by Kemi OJ.1. Training methods of aerobic exercise:(1) Rat treadmill speed is 15 m/min, and 10 min for adaptation;(2) Rat treadmill speed is increased to 20 m/min,50 min for continuous movement.Rats excersiced for 1h/day and 5 times/week,8weeks.2. Training methods of interval aerobic exercise(short for interval exercise):(1) Rat treadmill speed is 15 m/min, and 10 min for adaptation and then interval training;(2) High-intensity interval training was carried out for four minutes every time (22 m/min),3 minutes for interval (18 m/min);(3) Rats experienced 7 intervals in 1 exercise process, with 1-minute recovery time. Rats excersiced for 1h/day and 5 times/week,8weeks.Group of myocardial infarction +high-intensity interval aerobic training:The rats were trained one week after the surgery as follows (except group 1 and 2):Detections were carried out after the treadmill Training. The changes of the four hemodynamics indicators:LVSP,LVEDP,+dp/dtmax,-dp/dtmax was detedcted by Multichannel physiologic recorder.Method of TTC staining was used to observe changes in the organizational structure of infarction and infarct border area; Immunohistochemistry technique was used to tes,observe the changes of Bax,Bcl-2,Caspase-3 expression in infarction and infarct border area.Results:1.8 week aerobic exercise and interval aerobic training can both decrease infarct size; the size of infarct caused by interval aerobic training is smaller than that by aerobic training.2.8 week aerobic exercise and interval aerobic training can maintain the body weight of rats effectively, keep the blood pressure near normal levels, prevent left ventricular pressure from derceasing and inhibit the decrease of maximum rate of left ventricular Isovolumic pressure change (±dp/dt max); the effect of interval aerobic training is more significant than that of aerobic training.3.8 week aerobic exercise and interval aerobic training can decrease the expression of Proapoptotic bax in the infarct border area; the expression in aerobic exercise was significantly lower than that in interval aerobic training.4.8 week aerobic exercise and interval aerobic training can increase the expression of anti-apoptotic gene bcl-2 in the infarct border area; the expression in aerobic exercise was significantly higher than that in interval aerobic training.5.8 week Aerobic exercise and interval aerobic training can both decrease the expression of the protease caspase-3 that executes apoptosis in the infarct border area; the expression in aerobic exercise was significantly higher than that in interval aerobic training,which demonstrated that both the training methods can decrease myocardial cells apoptosis and the effect of interval aerobic training is more significantly.Conclusions:The results demonstrate that 8 week aerobic exercise and interval aerobic training can inhibit apoptosis of normal myocardial cells, decrease infarct size, and improve myocardial function effectively; the effect of interval aerobic training is more significant than that of aerobic training, which results from interval aerobic training reducing myocardial cells apoptosis.