大豆苷元对压力负荷性大鼠主动脉的保护作用

Protective effects of daidzein on aorta in rats induced by pressure overload

目的:研究大豆苷元(daidzein,Dai)对压力负荷性大鼠主动脉重构的保护作用及其机制。方法:采用腹主动脉缩窄法制备大鼠血管重构模型。造模d2起大鼠分别灌胃Dai30、60、120mg/kg,连续4WK。放射免疫分析法检测血浆血管紧张素Ⅱ(AngⅡ)含量;分光光度法检测主动脉一氧化氮(NO)含量和一氧化氮合酶(NOS)、Na+,K+-ATPase、Ca2+-ATPase活性。结果:与假手术组比较,模型组大鼠血浆AngⅡ含量和主动脉诱生型NOS(iNOS)活性升高,NO水平和结构型NOS(cNOS)、Na+,K+-ATPase、Ca2+-ATPase活性降低。Dai能显著提高主动脉NO含量及cNOS、Na+,K+-ATPase、Ca2+-ATPase活性,降低iNOS活性;明显抑制血浆AngⅡ的产生。结论:Dai对压力负荷性大鼠主动脉重构具有一定的改善作用,这可能与其抑制AngⅡ产生,上调NO水平有关。

Objective： To investigate the protective effects of daidzein（Dai） on aortic remodeling in rats induced by pressure overload and its mechanism. Methods： Aortic remodeling model of rats induced by pressure overload was prepared by constricti ng abdominal aorta. From day 2 , the rats were treated with Dai 30,60,120 mg/kg·d, po. Four week later, the content of angiotensin Ⅱ （ Ang Ⅱ ） in plasma was messured with radioimmunoassay. The content of nitric oxide（NO） and the activity of nitric oxide synthetase（ NOS）, Na^＋ , K ^＋ -ATPase and Ca2^＋ - ATPase in aorta were quantified with spectrophotometry. Results： Compared with sham - operated control group, the content of AngII in plasma and iNOS activity in aorta were significantly increased and NO content, activity of cNOS and Na^＋ ,K^＋ -ATPase and Ca2 ^＋ -ATPase in aorta were obviously decreased in model group. Treatment with Dai the NO content and the activity of cNOS , Na^＋ , K ^＋ - ATPase and Ca2 ^＋ - ATPase in aorta were significantly increased, the iNOS activity in aorta and the content of AngⅡ in plasma were significantly reduced. Conclusion： Dai can alleviate aortic remodeling in rats induced by pressure overload and its mechanism may be related to reducing the con, tent of Ang Ⅱ and raising NO level.