心肌血管紧张素Ⅱ在运动和高血压性心肌肥大时肌球蛋白重链变化中的作用探讨

Role of myocardial angiotensin Ⅱ in changes in myosin heavy chain in patients with exercise-induced or hypertensive myocardial hypertrophy

目的为了解心肌局部血管紧张素对运动和高血压两种不同的心肌肥大细胞表型是否参与变化调节。方法分析正常的自发性高血压大鼠产生运动后其心肌血管紧张素Ⅱ与肌球蛋白重链的异型变化,并通过十二周时间的游泳训练再行观察。结果正常安静的自发性高血压大鼠心肌血管紧张素Ⅱ与α-和β-肌球蛋白重链的变化没有明显的关联性(r=0.1801;0.1822;0.1798;P>0.05),但经过十二周的游泳训练后,其心肌β-肌球蛋白重链得到增加,血管紧张素Ⅱ中含量升高,两者呈正相关(r=0.7643;0.7568,P<0.05)。自发性高血压大鼠的心肌血管紧张素Ⅱ和β-肌球蛋白重链比WKY高87.86%和45.98%,两者呈正相关(r=0.8697;P<0.05),自发性高血压大鼠心肌血管紧张素Ⅱ与α-肌球蛋白重链呈负相关(r=-0.8711,P<0.05),WKY心肌血管紧张素Ⅱ与α-和β-肌球蛋白重链之间没有明显相关性(r=0.3013;0.0275;P>0.05)。运动自发性高血压大鼠β-肌球蛋白重链向α-肌球蛋白重链逆转,自发性高血压大鼠与α-/β-肌球蛋白重链呈正相关(r=0.8121;P<0.05)。结论心肌局部血管紧张素Ⅱ在运动性的心肌肥大中对α-肌球蛋白重链与β-肌球蛋白重链都具有上调作用,在运动逆转高血压心肌肥大时肌球蛋白重链,具有对α-/β-肌球蛋白重链的上调作用。

Objective To investigate the role of myocardial local angiotensin II in the changes in myosin heavy chain in patients with exercise-induced or hypertensive myocardial hypertrophy. Methods The changes in myocardial angiotensin II and myosin heavy chain after exercise in normal spontaneously hypertensive rats were analyzed, and observation was performed after the 12-week swimming training. Results In normal calm spontaneously hypertensive rats, there were no significant correlations between the changes in myocardial angiotensin II and α- and β-myosin heavy chain（r=0.1801, 0.1822, and 0.1798; P〉0.05）, but after the 12-week swimming training, myocardial β-myosin heavy chain and angiotensin II were increased, and there was a positive correlation between them（r=0.7643 and 0.7568, P〈0.05）. Myocardial angiotensin II and β-myosin heavy chain in spontaneously hypertensive rats were 87.86% and 45.98%higher than those in WKY rats, and there was a positive correlation between them（r=0.8697, P〈0.05）. In spontaneously hypertensive rats, myocardial angiotensin II was negatively correlated with α-myosin heavy chain（r=-0.8711, P〈0.05）.There were no significant correlations between WKY myocardial angiotensin II and α- and β-myosin heavy chains（r=0.3013 and 0.0275, P〉0.05）. In rats with exercise-induced spontaneous hypertension, β-myosin heavy chain was reversed to α-myosin heavy chain, and spontaneous hypertension was positively correlated with α-/β- myosin heavy chain（r=0.8121, P〈0.05）. Conclusion Myocardial local angiotensin II upregulates α- and β-myosin heavy chains in exercise-induced myocardial hypertrophy, and when hypertensive myocardial hypertrophy is reversed by exercise, it can upregulate α-/β-myosin heavy chain.