血管紧张素Ⅱ在运动性心肌肥大中的作用

为探讨心脏局部ＡｎｇⅡ在运动性心肌肥大中的作用，本文在长期游泳训练造成的心肌肥大模型上观察心脏系数、心肌局部和血浆ＡｎｇⅡ含量的变化，同时观察应用转换酶抑制剂Ｃａｐｔｏｐｒｉｌ对心肌肥大的心脏系数及心肌和血浆ＡｎｇⅡ含量的影响。结果表明，运动可引起左右室心肌肥大，左右室心脏系数较对照组分别增加了１９％和２３．４％，这种心肌局部肥大和血浆ＡｎｇⅡ的含量较对照组分别增加了４８．３％和４４．５％（ｐ＜０．０１），应用Ｃａｐｔｏｐｒｉｌ可阻断运动性心肌肥大的发生，左右室系数较单纯运动心肌肥大组分别降低了１８．２％和１７．８％且血浆和心肌局部ＡｎｇⅡ的含量较单纯运动心肌肥大组分别降低了５８％和５５．８％（ｐ＜０．０１），相关分析结果提示，心肌局部ＡｎｇⅡ的含量与心肌肥大的程度成显著正相关（ｒ＝０．６６５ｐ＝０．０１３），由此证明心肌局部ＡｎｇⅡ参与了运动性心肌肥大的发生过程。

THE EFFECT OF ANGII ON EXERCISE-INDUCED MYOCARDIAL HYPERTROPHY

The changes of cardiac coefficient, cardiac and plasma Ang l were determined in long-term swimming trained rats to study the effect of Ang Ⅱ(derived from cardiac tissue)on exercise induced myocardial hypertrophy. And the effects of captopril on cardiac coef ficient and contents of cardiac and plasma Ang Ⅱ of myocardial hypertrophy were also studied simultaneously. The results showed that exercise could induce myocardial hypertro phy, the cardiac coefficient of both ventricles were significantly elevated, the increases of left and right ventricular coefficients were l9%and 23.4% respectively compared with the sedentary rats; meanwhile, the contents of cardiac and plasma Ang Ⅱ were signifi cantly higher (48.8%and4.45% respectively) than the controls(p<0.01).Administration of captopril could prevent myocardial hypertrophy and the increases of cardiac and plasma Ang Ⅱ.In addition, the contents of cardiac Ang Ⅱwere correlated to myocardial hypertrophy(r=0.665,p=0.013).Therefore, Ang Ⅱ derived from cardiac tissue played an important role in the development of exercise induced myocardial hypertrophy.