肌节骨架蛋白ɑ-actinin和Myomesin-1在肾血管性高血压大鼠心室肌中的表达

目的探讨肾性高血压大鼠左心室壁重构过程中肌节骨架蛋白ɑ-actinin和Myomesin-1的表达变化规律。方法采用双侧肾动脉狭窄法制作动物模型,40只SD大鼠随机分假手术组(control)、术后2周组、术后5周组和术后7周组,血压及左室重量指数评价造模成功后,取左心室肌组织,采用免疫组织化学染色和Western blotting检测各组左心室肌组织ɑ-actinin和Myomesin-1的表达,并进行图像分析和统计学处理。结果ɑ-actinin和Myomesin-1蛋白表达主要呈点状或短棒状表达,在高血压进程中呈现弥散状分布的特点;免疫组织化学和Western blotting结果显示,与对照组相比,术后2周组ɑ-actinin和Myomesin-1蛋白表达均显著增高(P0.01);在高血压进程中,两蛋白的表达量均随时间增加而下降,组间比较差异具有统计学意义(P0.05);ɑ-actinin阳性表达区的宽度在高血压进程中呈先降低后升高的趋势,且相邻组间差异均具有统计学意义(P0.05)。结论ɑ-actinin和Myomesin-1参与高血压心肌肥厚的发生,提示肌节收缩能力与血压的高低有关。

Expression of sarcomere skelemin a-actinin and Myomesin-1 of the ventricle in renal hypertensive rats

Objective To explore the variation of sarcomere skelemin ɑ-actinin and Myomesin-1 during the left ventricular wall re-modeling in the rats with renal hypertension. Methods The animal model was prepared by bilateral renal artery stenosis, and renal artery was freed in the control group. Forty rats were randomly divided into sham operation group, two weeks group, five weeks group and seven weeks group after operation. The model quality of hypertensive rats were assessed by noninvasive blood pressure analysis tester and the indexes of left ventricular weight (LVW/BW). The immunohistochemistry and Western blotting was used to detect the expression of ɑ-actinin and Myomesin-1 in the ventricle muscle tissues, and microscope image analysis and statistical processing were carried out. Results ɑ-actinin and Myomesin-1 were expressed in myocardium and showed diffusion distribution during hypertensive. The results of the immunohistochemistry and Western blotting showed that the expression of ɑ-actinin and Myomesin-1 increased significantly at 2 weeks group after operation compared with the control group（P<0.01）, and declined significantly than control group in the process of hypertensive（P<0.01）. In addition, the width of positive expression exhibited a trend from declining to rising, and showed significance difference between neighboring groups（P<0.05）. Conclusion ɑ-actinin and Myomesin-1 play a role in the process of myocardial hypertrophy, suggesting that the level of blood pressure is associated with the sarcomere contractility.