腹主动脉缩窄大鼠模型左室心肌血管紧张素Ⅱ-1型受体及其mRNA的表达

Expression of left ventricular myocardium angiotensin Ⅱ type-1 receptor in rats with abdominal aortic banding

目的通过建立腹主动脉缩窄大鼠模型,研究腹主动脉缩窄大鼠左室心肌血管紧张素Ⅱ-1型(AT1)受体mRNA表达及其受体蛋白的改变。方法30只雄性SD大鼠随机分为假手术组(14只)和模型组(16只)。模型组根据Doering等的方法,用银夹造成腹主动脉部分狭窄(银夹内径0.7 mm)。8周后免疫组化法进行AT1受体蛋白染色,并用灰度值作为其含量指标行图像分析,即时PCR扩增后分析并测定其mRNA表达。结果模型组造模8周时AT1受体蛋白及其mRNA表达较假手术组显著升高(P<0.01)。结论腹主动脉缩窄大鼠所致心肌纤维化心肌AT1基因转录与翻译水平发生改变,通过AT1下游信号通路传导作用,促进心肌纤维化。

Objection To investigate expression of left ventricular myocardium angiotensin Ⅱ type-1 receptor and in abdominal aortic banding model rats. Methods 30 SD rats were randomly divide into sham-operation group （14 rats） and model group （16 rats）. Myocardial fibrosis rat model was established by partially banding abdominal aorta with silver clip. Gray scale value of left ventricular myocardium angiotensin Ⅱ type-1 receptor was measured after immunohistochem- istry stain. The expression of angiotensin Ⅱ type receptor mRNA was detected with real-time PCR. Results In the 8th week, the average optical density value and the mRNA expression of left ventricular myocardium angiotensin Ⅱ type-1 receptor were increased obviously in model group, compared with sham-operation group （P〈0.01）. Conclusion This study supports that the level of AT1 transcription and translation increase in model rat with myocardial fibrosis estab- lished by partially abdominal aorta banding, which enhances the signaling path of Ang Ⅱ-AT1 and contribute to myocardial fibrosis.