基于动脉压力感受性反射探讨针刺人迎穴降压机制

Exploration of Antihypertensive Mechanism on Acupuncturing at Renying(ST9)Based on Arterial Baroreflex

目的观察针刺大鼠双侧人迎穴对血压、压力感受性反射敏感性(BRS)和中枢肾素-血管紧张素系统(RAS)的影响,从动脉压力感受性反射(ABR)角度探讨其降压机制。方法DSI植入术后,将18只自发性高血压病大鼠按体质量随机分为模型对照组、单纯针刺组及电针组各6只,6只Wistar大鼠为空白对照组。单纯针刺组只针刺大鼠双侧人迎穴,不作任何手法;电针组在此基础上加用电针1 min,留针20 min;空白及模型对照组与以上两组采用同样方法抓取固定,不予其他任何干预。采用DSI植入系统收集4组干预前及每日干预后连续30 min血压值;分别在干预前及最后一次干预后测算2次BRS。处死大鼠,取延髓,分别进行血管紧张素Ⅱ(AngⅡ)、血管紧张素1型受体(AT1R)和血管紧张素转换酶(ACE)的指标检测。结果单纯针刺组干预后第14、21、28天收缩压(SBP)、舒张压(DBP)分别与干预前对比,均有明显下降,差异具有统计学意义(P<0.05);电针组SBP干预后第7天、DBP干预后第14天可见明显下降(P<0.05),其后均呈持续下降趋势,较干预前差异有统计学意义(P<0.05);干预后第28天两组间对比,电针组SBP下降幅度更大(P<0.05),DBP两组间差异无统计学意义(P>0.05)。单纯针刺组、电针组的BRS_(PE)、BRS_(SNP)干预后与干预前对比,均可见明显提高,差异具有统计学意义(P<0.05)。干预后单纯针刺组、电针组分别与模型对照组对比,延髓及血清中AngⅡ水平、延髓内AT1R的蛋白和mRNA表达均可见明显下降,差异具有统计学意义(P<0.05),ACE阳性细胞表达也可见明显减少;电针组对血清中AngⅡ、延髓内AT1R的蛋白和mRNA表达下调更明显,与单纯针刺组对比差异有统计学意义(P<0.05)。结论针刺人迎穴能有效降低大鼠血压,电针对SBP更敏感;能提高动脉压力感受的迷走和交感反射敏感性;还能有效降低延髓内ACE-AngⅡ-AT1的整体水平。其降压机制可能是通过抑制中枢RAS活性,从而改善ABR功能发挥作用。

Objective To observe the effect of acupuncture at bilateral Renying(ST9)on blood pressure,baroreflex sensitivity(BRS)and central renin-angiotensin system(RAS),and to discuss its antihypertensive mechanism from the perspective of arterial baroreflex(ABR).Methods After DSI implantation,18 SHRs were randomly divided into model control group,acupuncture group and electroacupuncture group according to body weight,6 Wistar rats as blank control group.In the acupuncture group,only stimulate bilateral Renying(ST9)without any manipulation;the electroacupuncture group added electroacupuncture for 1 minute and left the needle for 20 minutes;the blank and model control groups were grasped and fixed in the same way as the above two groups without any other intervention.The DSI implantation system was used to collect blood pressure for 4 consecutive weeks before and daily intervention for 30 minutes,and to measure the BRS of 4 groups before and after the whole intervention.Then killed rats,the medulla oblongata was taken,and the indexes of Ang Ⅱ,AT1R and ACE were detected respectively.Results The systolic blood pressure(SBP)and diastolic blood pressure(DBP)of the 14 th,21 st and 28 th days after intervention in acupuncture group were significantly decreased compared with their values before intervention,and the differences were statistically significant(P<0.05);In the electroacupuncture group,there was a significant decrease on the 7 th day’s SBP and the 14 th day’s DBP compared before(P<0.05),and there had continuous downward trends,which were statistically different from that before(P<0.05);on the 28 th day,in the comparison between the two groups,the electroacupuncture group had a greater decrease in SBP(P<0.05),and there was no significant difference in DBP between the two groups(P>0.05).Compared BRS_(PE) and BRS_(SNP) after intervention with before,there had significant improvements both in the acupuncture and the electroacupuncture group,and the differences ware statistically significant(P<0.05).After intervention,compared the acupuncture and the electroacupuncture group with the model control group,the levels of Ang Ⅱ in the medulla oblongata and serum,and the expression of AT1R protein and mRNA in the medulla oblongata were significantly decreased(P<0.05),and the ACE positive cells’expression also significantly reduced;besides,the electroacupuncture group significantly reduced the level of Ang Ⅱ in serum and the expression of AT1R protein and mRNA in the medulla oblongata compared with the acupuncture group(P<0.05).Conclusion Acupuncturing at Renying(ST9)can effectively reduce blood pressure in rats,and electroacupuncture is more sensitive to SBP;it can increase the arterial barorefilx sensitivity of vagal and sympathetic;also can effectively reduce the overall level of ACE-Ang Ⅱ-AT1 in the medulla oblongata.Its antihypertensive mechanism may work by inhibiting central RAS activity,and then improving ABR function.