电针“百会”“太冲”对自发性高血压大鼠主动脉Ang Ⅱ、Ang(1-7)蛋白表达的影响

Re gulating Effects of Electroacupuncture at Taichong and Baihui on Protein Expression of Ang Ⅱ and Ang(1-7) in Aorta tissue of SHR

目的观察电针"百会""太冲"对SHR主动脉血管紧张素Ⅱ(AngⅡ)、血管紧张素(1-7)[Ang(1-7)蛋白表达的影响,以主动脉AngⅡ、Ang(1-7)蛋白为切入点,研究其可能的机制。方法选取12周龄雄性自发性高血压大鼠(SHR)24只,随机分为电针组(EA)和模型组(SHR),Wistar-Kyoto(WKY)大鼠12只作为空白对照组(WKY),每日上午针刺电针组"百会"与双侧"太冲"穴,并将电针仪的正负极分别连于"百会"、右侧"太冲"穴,电流强度1 mA,频率2 Hz/15 Hz,留针20 min,连续针刺30 d。空白组和模型组每天进行与电针组相同的抓捉固定刺激。用无创血压仪检测各组大鼠尾动脉收缩压,HE染色后观察其组织形态,并用计算机图像分析系统测定主动脉血管中膜面积(MA)以及血管壁厚(WT)、血管内径(LD),计算LD/WT比值。用ELISA法检测主动脉组织AngⅡ、Ang(1-7)的蛋白含量并进行统计学分析。结果 1)模型组收缩压较正常组显著升高(P <0.01),电针组收缩压较模型组显著降低(P <0.01)。2)模型组较正常组WT明显增厚(P <0.01)、LD明显缩小(P <0.01)、LD/WT比值明显增大(P <0.01)、MA明显增大(P <0.05)。电针组较模型组WT明显缩小(P <0.01)、LD明显增大(P <0.01)、LD/WT比值明显减小(P <0.01)、MA面积明显缩小(P <0.01)。3)ELISA结果显示,与正常组相比较,模型组主动脉组织AngⅡ蛋白表达显著升高(P <0.01),Ang(1-7)蛋白表达显著降低(P <0.01),AngⅡ/Ang(1-7)比值显著增大(P <0.01)。与模型组相比较,电针组主动脉组织AngⅡ蛋白表达明显降低(P <0.01),Ang(1-7)蛋白表达显著升高(P <0.05),AngⅡ/Ang(1-7)比值显著缩小(P <0.01)。结论电针"百会""太冲"可有效改善SHR主动脉血管重塑,保护主动脉,其机制可能是电针通过激活主动脉局部RAS系统ACE2-Ang(1-7)-Mas受体轴,促进Ang(1-7)蛋白表达,抑制AngⅡ蛋白表达来实现。

Objective: To investigate the protective effects of electroacupuncture(EA) on aorta AngⅡ and Ang(1-7) protein expressions in spontaneously hypertensive rats(SHRs),and to explore its possible mechanism. Methods: 24 male 12-week-old SHRs were randomized into the model group and EA group,with 12 in each.12 Wistar Kyoto rats(WKY) were selected as the normal control group. EA was applied on Taichong and Baihui (2/15 Hz,1mA,20min) in EA group,once a day for 30 days. The other two groups only received the same grasping and fixation stimulation. The blood pressure(SBP) of tail arteries of each group was detected by non-invasive blood pressure monitor. Pathological changes of aorta tissues in rats were observed by HE staining and electron microscope. Medial area of the aorta(MA),vessel wall thickness(WT) and vessel lumen diameter(LD) were measured by computer image analysis system,and LD/WT ratio was calculated. The protein content of AngⅡ and Ang(1-7) in aorta tissues were detected by ELISA. Results: 1)After treatment,SBP in the model group was significantly higher than that in the normal group (P < 0.01);the SBP in EA group was significantly lower than that in the model group (P < 0.01). 2)Compared with the normal group,WT of the model group was significantly thickened(P < 0.01),while LD was significantly reduced(P < 0.01);LD/WT ratio and MA were increased significantly(P < 0.05 or P < 0.01). Compared with the model group,WT of EA group decreased significantly(P < 0.01),while LD increased significantly(P < 0.01);LD/WT ratio and MA decreased significantly(P < 0.01). 3) The results of ELISA showed that the protein expression of Ang(1-7) in aorta tissues of SHRs were significantly up-regulated by EA(P < 0.05),while the protein expression of AngⅡ and AngⅡ/Ang(1-7) were down-regulated(P < 0.01). Conclusion: EA at Baihui and Taichong can effectively improve the process of aorta vascular remodeling and protect the aorta of SHR,which might be mediated by activating the ACE2-Ang(1-7)-Mas receptor axis of the local aortic RAS system,promoting the expression of Ang(1-7) protein and inhibiting of the protein expression of AngⅡ.