通心络胶囊改善压力超负荷大鼠心肌肥厚和缝隙连接蛋白Cx43重构的研究

目的 探索通心络胶囊对压力超负荷大鼠心肌肥厚和QT离散度以及缝隙连接蛋白43(connexin 43,Cx43)表达的影响。 方法 随机均分45只雄性SD大鼠成3组:对照组(control,C),模型组(model,M),治疗组(treatment,T),腹主动脉缩窄手术建立压力超负荷大鼠模型,予通心络胶囊1.5 g/(kg·d)]干预12周后,以多普勒超声心动图检测,同时测定大鼠QT离散度,大鼠处死后取左室心肌组织行HE染色,以免疫组化方法检测Cx43的表达及分布,RT-PCR法检测Cx43 mRNA的表达。 结果 M组大鼠心脏多普勒结果与C组比较显示IVSs、VPWs、LIVSd和LVPWd均有增加(均P<0.01);而T组和M组比较,以上检测参数则得以改善。与C组相比,M组QT离散度明显延长(P<0.01),与M组相比,T组QT离散度明显缩短(P<0.01)。同时HE染色显示:与C组相比,M组心肌细胞肥大明显(P<0.01),呈无序排列,T组与M组比较,心肌肥大及排列均较其改善(均P<0.01)。RT-PCR及免疫组化检测结果均显示:与C组相比,M组Cx43 mRNA和蛋白的表达均有明显下调(均P<0.05),而T组与M组相比,Cx43 mRNA和蛋白的表达有所上调(均P<0.05)。 结论 通心络胶囊在改善压力超负荷大鼠心肌肥厚的同时也缩短QT离散度及上调Cx43的表达。 

Tongxinluo can improve cardiac hypertrophy and Cx43 remodeling in pressure overload rats

Objective To observe the effects of Tongxinluo on myocardial hypertrophy, QT dispersion and connexin 43 (Cx43) expression in rats under pressure overload. Methods Total 45 male SD rats were randomly divided into three groups:control (group C), model (group M) and treatment (group T). A model of rats under pressure overload was established by abdominal aortic banding. After 12 weeks of treatment with Tongxinluo1.5 g/(kg·d)], echocardiogram examination was conducted, and cardiac electrophysiological recorder was used to record the QT dispersion of rats. After these rats were sacrificed, HE staining was performed to observe the pathological morphology of left ventricle myocardial tissue, immunohistochemistry (IHC) was conducted to determine the expression and distribution of Cx43, and RT-PCR method was employed to determine Cx43 mRNA expression. Results A model of rats with myocardial hypertrophy under pressure overload was successfully established. Echocardiographic detection indicates that compared with group C, group M had obvious Ventricular hypertrophy, IVSs, VPWs, LIVSd and LVPWd were increased obviously (P<0.01); compared with group M, the above parameters in group T were improved (P<0.01). Compared with group C, the QT dispersion of group M was obviously increased (P<0.01), and Tongxinluo intervention could reduce the QT dispersion of rats under pressure overload (P<0.01). Compared with group C, cardiomyocyte hypertrophy and irregular arrangement could be seen in group M, and the expressions of Cx43 and Cx43 mRNA in left ventricle myocardial tissue were greatly reduced (P<0.05). Compared with group M, irregular arrangement of myocardial cells in group T was improved, and the expressions of Cx43 and Cx43 mRNA were significantly up-regulated (P<0.05). Conclusion For rats under pressure overload, Tongxinluo can improve myocardial hypertrophy, shorten QT dispersion and improve Cx43 reconstruction.