Elucidation of the mechanism that rehabilitation therapeutic exercise protects myocardium

我们使用WKY大鼠。（1）平板运动4周后，结扎左冠状动脉30 min，再灌注（缺血再灌注，IR）。4周后，EX组左室舒张末期内径（LVDd）明显短于无运动组（no-EX），左室射血分数（LVEF）明显高于无运动组（no-EX）。（2）IR后进行EX。EX组LVDd和尿量显著低于no-EX组，LVEF和心率显著高于no-EX组。（3）IR前后给予EX和缬沙坦治疗4周，治疗组血压、尿量、体重均显著低于非治疗组，心脏重量显著轻于非治疗组。治疗组非缺血左室心肌TNF-α mRNA含量明显高于非治疗组。治疗组的存活率明显高于未治疗组。（4）结扎左冠状动脉前、后分别行EX检查。EX组的生存率明显高于无EX组。实验组在结扎后1周运动时的氧摄取量明显高于对照组，提示缺血前和/或缺血后给予EX可改善心脏和心肺功能，提高存活率。提示TNF-α在EX和缬沙坦的心肌保护作用中起重要作用。

We used WKY rats.(1)After the treadmill exercise for 4 weeks (EX), the left coronary artery was ligated for 30min and then reperfused (ischemia reperfusion, IR). Four weeks later, left ventricular end-diastolic diameter (LVDd) in the EX group was significantly shorter than that in the no-exercise (no-EX) group, and left ventricular ejection fraction (LVEF) in the EX group was significantly more than that in the no-EX group.(2)After the IR, EX was performed. The values of LVDd and urine volume in the EX group were significantly lower than those in the no-EX group, and the values of LVEF and heart rate were significantly higher than those in the no-EX group.(3)The treatments with EX and the administration of valsartan for 4 weeks were performed before and after the IR. The values of blood pressure, urine volume, body weight in the treated-group were significantly lower than those in the non-treated-group, and heart weight was significantly lighter than that in the non-treated-group. The value of TNF-α m-RNA of non-ischemic left ventricular myocardium in the treated-group was significantly higher than that in the non-treated-group. The survival rate in the treated-group was significantly higher than that in the non-treated-group.(4)The EX was performed before and after the ligation of left coronary artery. The survival rate in the EX group was significantly higher than that in the no-EX group. The value of the oxygen intake during exercise in the EX group at 1 week after the ligation was significantly higher than that in the no-EX group.These results suggest that the EX before and/or after the cardiac ischemia improves the cardiac and cardiorespiratory functions, and the survival rate. These results also suggest that the TNF-α may play a important role in these cardioprotective effects of EX and valsartan.