The Protective Effect And Mechanism Of Electroacupuncture "Baihui" And "Taichong" On SHR Aortic Injury

OjectiveHypertension,as a high incidence of cardiovascular system,is an important factor endangering the function of artery and blood vessel.Its metabolic disorder and hemodynamic dysfunction can directly damage the function of artery and blood vessel.It is considered to be the main risk factor for the occurrence and death of cardiovascular and cerebrovascular diseases,and has great harm to fole's health.Acupuncture has been proved to protect aorta,prevent aortic injury and improve aortic vascular remodeling,but there is no in-depth understanding of its specific mechanism.RAS is one of the most important neuroendocrine regulation mechanisms in human body.It is generally believed that RAS plays a key role in the regulation of blood pressure,and is closely related to the pathogenesis of hypertension and arterial injury caused by hypertension.Ang? plays the role of vasoconstriction and pressor in RAS,while Ang(1-7)antagonizes Ang? through ACE2-Ang(1-7)-Mas receptor axis.Ang(1-7)-Mas receptor axis antagonizes Ang? and exerts the function of blood pressure reduction and vasodilation.Therefore,this study takes SHR as the research object,and takes Ang? and Ang(1-7)proteins of aorta as the breakthrough point to study the protective effect of Electroacupuncture on SHR aorta and its possible mechanism.The treatment of injury provides certain theoretical basis and clinical guidance.Methods24 male 12-week-old SHRs were randomized into model and EA group,with 12 in each.12 Wistar Kyoto rats(WKY)were selected as normal control group.Electroacupuncture was applied on Taichong(LR 3)and Baihui(DU 20)(2/15 Hz,1mA,20min)of SHRs in EA group once a day for 30 days.The oth er 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,Masson 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 Ang? 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 the 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 and LD/WT ratio were significantly reduced(P<0.01,P<0.01),MA were increased significantly(P<0.05).After treatment,Compared with the model group,WT of the EA group decreased significantly(P<0.01),while LD and LD/WT ratio were increased significantly(P<0.01,P<0.01),MA decreased significantly(P<0.01).(3)The results of ELISA showed that the protein content of Ang(1-7)in aorta tissues of SHRs were significantly less than WKY(P<0.01),while the protein content of Ang? and AngII/Ang(1-7)were increase(P<0.01).At the same time,the results of ELISA showed that the protein content of Ang(1-7)in aorta tissues of SHRs were significantly up-regulated by EA(P<0.05),while the protein content of Ang? and Ang?/Ang(1-7)were down-regulated(P<0.01).Conclusion(1)EA at LR 3 and DU 20 has significant antihypertensive effect on SHR rats.(2)EA at LR 3 and DU 20 can improve the pathological state of aorta caused by hypertension in SHR rats,reverse aortic remodeling and protect aorta.(3)EA at LR 3 and DU 20 can improve the content of Ang(1-7)protein and decrease the content of Ang? protein in aorta of SHR,which suggests that electroacupuncture may play an aortic protective role by activating the ACE2-Ang(1-7)-Mas receptor axis in the local RAS system of aorta.