替米沙坦对肾性高血压大鼠心肌β-肌球蛋白重链表达的影响

Effects of telmisartan on the expression of myocardial β-myosin heavy chain in rats with renovascular hypertension

目的观察替米沙坦对肾性高血压大鼠心肌β-肌球蛋白重链(β-MHC)的影响。方法雄性SD大鼠30只,随机分为假手术组、模型组和替米沙坦组,每组10只。模型组及替米沙坦组采用两肾一夹法,制备肾血管性高血压模型,替米沙坦组用替米沙坦(10 mg.kg-1.d-1)灌胃干预。术后8周,经动脉插管测血压,经超声心动图评估心脏结构及功能,HE染色观察心肌病理改变;RT-PCR法检测心肌β-MHC mRNA水平。结果与假手术组相比,模型组大鼠血压显著升高,心肌肥厚(均P<0.01),细胞直径增大,排列不整齐。与模型组相比,替米沙坦组大鼠血压明显下降,心肌无明显肥厚(均P<0.01),其心肌β-MHC mRNA表达水平较模型组明显降低(P<0.05)。结论替米沙坦可下调肥厚心肌β-MHC基因表达水平,可能与其逆转心肌肥厚相关。

Objective To observe the effects of telmisartan on the expression of myocardial β-myosin heavy chain（β-MHC） mRNA in rats with two-kidney one clip（2K1C） ways.Methods Thirty male Sprague-Dawly（SD） rats were randomly divided into sham-operation group（sham group,n=10）,model group（M group,n=10） and telmisartan group（T group,n=10）.2K1C hypertensive model was established in SD rats by chronic partial occlusion of left renal artery.Eight weeks after the operation,the blood pressure was tested by arterial catheterization.The myocardial structure and function were obtained by ultrasonography,and the change of myocardial histopathology were observed by HE staining methods.RT-PCR was used to detect the expression of β-MHC mRNA in myocardial tissues.Results Eight weeks later,the blood pressure and the thickness of left ventricle in model group were significantly higher than those in sham group.The pathologic finding indicated the increasing diameter and irregular arrangement of myocytes.The blood pressure in T group were significantly lower than those in model group（P0.01,respectively）.There are no markedly myocardial hypertrophy,and the β-MHC mRNA expression of myocardial tissue lower than that in model group（P0.05）.Conclusion Telmisartan could decrease the expression of β-MHC,which may be one of mechanisms for the regression of myocardial hypertrophy.