茶多酚对异丙肾上腺素致大鼠心肌肥厚的保护作用

目的观察茶多酚对大鼠心肌肥厚的保护作用并讨论其相关可能作用机制。方法采用皮下注射异丙肾上腺素（ISO）建立大鼠心肌肥厚模型，将28只SD大鼠随机分为对照组、模型组、美托洛尔组、茶多酚组，灌胃给药连续14d后，取心脏称重后计算全心重量指数及左心重量参数；分别检测测定心肌组织一氧化氮合酶（NOS）活性及心肌组织血管紧张素Ⅱ（AngⅡ）及钙调神经磷酸酶（CaN）的水平。结果与模型组相比，茶多酚能显著改善心脏质量指数，心肌组织NOS活性显著升高、AngⅡ含量降低、CaN活性明显降低。结论茶多酚对异丙肾上腺素所致大鼠心肌肥厚具有保护作用，其作用机制可能与提高NO水平、降低CaN活性、抑制AngⅡ有关。

Protective Effects of Tea Polyphenol on Isopropylarterenol Caused Cardiac Hypertrophy

Objective To observe the protective effect of tea polyphenol on myocardial hypertrophy caused by isopropylarterenol（ ISO ）in rats and explore its possible mechanism. Methods The mouse model of myocardial hypertrophy was established by hypodermic injection of isoproterenol. Twenty-eight myocardial hypertrophy mice were randomly divided into 4 groups： normal control group, model group, tea polyphenol group, and Metoprolol group. Once the model was formed, the rats were administrated with tea polyphenol in intragastric way from the second day for 14 d. Then the heart were taken under anesthesia, the indexes of whole heart and left ventricle were calculated and NOS activity and Ang Ⅱ and CaN level of myocardial tissue were determined with kits. Results There was obvious difference between tea polyphenol group and model group. Indexes of whole heart and left ventrical were much better in tea polyphenol group, NOS activity was increased while Ang Ⅱ and CaN concentration was decreased in left ventricle. Conclusion Tea polyphenol has a protective effect on myocardial hypertrophy caused by Iso, and its mechanism may be related with NO concentration promotion and clearance of Ang Ⅱ and CaN.