机械负荷过度性心肌肥大时心脏局部和循环RAS的变化

本实验用大鼠腹主动脉狭窄伴左肾切除(AA)和动静脉瘘(AVF)模型,观察了压力和容量负荷性心肌肥大时,心室肌及血浆中血管紧张素Ⅰ、Ⅱ(AngⅠ、Ⅱ)和血浆肾素活性的变化。实验结果表明:AC组动物心室肌AngⅠ、Ⅱ均明显高于对照组,而血浆中AngⅠ、Ⅱ和肾素活性在重度肥大的AC组则明显降低。AVF组心肌和血浆AngⅠ、Ⅱ都显著高于对照组。提示在压力负荷引起的心肌肥大中,心脏局部RAS可能起着重要作用,而在单纯容量负荷性心肌肥大时,心脏局部和循环RAS可能都参与了心肌肥大的发生和发展。

THE ALTERATION OF LOCAL AND CIRCULATING RENIN-ANGIOTENSIN SYSTEM(RAS) DURING MECHANICAL-OVERLOAD CARDIAC HYPERTROPHY OF RATS

We studied the alteration of local and circulat-ing RAS during cardiac hypertrophy caused by ab-dominal aorta constriction (AC, with nephrectomyof left side) and aorta-vena fistula (AVF). Bothventricular and plasma angiotensin Ⅰ and Ⅱ (AngⅠ. Ⅱ), and plasma, renin actvity (RA) weremeasured by means of radioimmunoassay after twoand seven weeks of surgery. Despite the level ofplasma Ang Ⅰ, Ⅱ and RA were not enhanced, theventricular Ang Ⅰ and Ⅱ were increased signifi-cantly in AC rats (v. s. SO group P<0. 05 ).However, in AVM rats both ventricular and plas-ma Ang Ⅰ, Ⅱ and plasma RA were increased ob-viously. These results suggest that cardiac RASmay play an important role in the development ofcardiac hypertrophy during pressure overload. Butin the volume-overload cardiac hypertrophy bothlocal and circulating RAS may be involved.