基于胃泌素/胆囊收缩素B受体探讨针刺“人迎”“足三里”的降压机制

Study on the antihypertensive mechanism of acupuncture at“Renying”(ST9)and“Zusanli”(ST36)via gastrin/cholecystokinin B receptors

目的:观察针刺对自发性高血压大鼠(SHR)血清胃泌素含量及尿钠排泄的影响,探讨针刺降压的作用机制。方法:将32只SPF级雄性SHR随机分为模型组、氢氯噻嗪组、针刺组和假针组,每组8只;8只Wistar-kyoto大鼠为对照组。氢氯噻嗪组予氢氯噻嗪溶液(10 mg·kg^(-1)·d^(-1))灌胃;针刺组予双侧“人迎”“足三里”干预,每次20 min,每10 min捻转1次;假针组在双侧“人迎”“足三里”附近的非穴位点进行干预,每次20 min,每10 min捻转1次。3组均每日治疗1次,持续4周。治疗前及治疗第1、2、3、4周末测量各组大鼠尾动脉收缩压;HE染色观察肾组织病理形态变化;ELISA法检测血清胃泌素含量;原子吸收光谱法检测尿钠含量;Western blot法检测肾组织胆囊收缩素B受体(CCKBR)和Na^(+)/K^(+)-ATP酶蛋白的表达水平;荧光定量PCR法检测肾组织CCKBR和Na^(+)/K^(+)-ATP酶α1亚基(ATP1A1)mRNA表达水平。结果:与对照组相比,干预前、干预第1、2、3、4周模型组尾动脉收缩压显著升高(P<0.05)。干预前模型组、氢氯噻嗪组、针刺组和假针组24 h尿量显著降低(P<0.05)。干预后模型组24 h尿量及尿钠排泄显著下降(P<0.05);血清胃泌素含量降低(P<0.05);肾小球轻度淤血,周围可见少量淋巴细胞浸润;肾组织CCKBR蛋白和mRNA表达水平显著下降(P<0.05),Na^(+)/K^(+)-ATP酶蛋白和ATP1A1 mRNA表达水平显著升高(P<0.05)。与模型组相比,干预第2、3、4周氢氯噻嗪组和针刺组尾动脉收缩压显著下降(P<0.05);氢氯噻嗪组和针刺组24 h尿量及尿钠排泄显著提高(P<0.05);血清胃泌素含量升高(P<0.05);肾组织病理改变明显减轻,肾组织CCKBR蛋白和mRNA表达水平显著升高(P<0.05),Na^(+)/K^(+)-ATP酶蛋白和ATP1A1 mRNA表达水平显著下降(P<0.05)。假针组可见肾组织血管周围少量淋巴细胞灶性浸润。结论:针刺双侧“人迎”“足三里”可显著降低SHR的尾动脉收缩压,其机制可能与提高血清胃泌素含量,提高CCKBR的表达,抑制钠泵重吸收,从而促进尿钠排泄有关。

Objective To observe the effect of acupuncture on serum gastrin content and urinary sodium excretion in spontaneously hypertensive rat(SHR),so as to explore its potential mechanism in the treatment of hypertension.Methods Thirty-two male SHRs were randomly divided into model,hydrochlorothiazide,acupuncture and sham acupuncture groups,with 8 rats in each group,and 8 male Wistar-kyoto rats were taken as the control group.Rats in the hydrochlorothiazide group received gavage of hydrochlorothiazide solution(10 mg·kg^(-1)·d^(-1)),once daily for 4 weeks.Acupuncture was applied to bilateral“Renying”(ST9)and“Zusanli”(ST36)or non-acupoint on both sides for rats in the acupuncture and sham acupuncture groups,with manual stimulation every 10 minutes for a total of 20 minutes,once a day for a total of 4 weeks.The systolic blood pressure of the tail-artery was measured before and 1,2,3,and 4 weeks after the intervention.HE staining was used to observe the pathological changes in renal tissue.Serum gastrin contents were detected using enzyme-linked immunosorbent assay(ELISA).Urinary sodium content was measured by atomic absorption spectrometry.The expression levels of cholecystokinin B receptor(CCKBR)and Na^(+)/K^(+)-ATPase proteins in renal tissue were detected by Western blot,and the mRNA expression levels of CCKBR and theα1 subunit of Na^(+)/K^(+)-ATPase(ATP1A1)were detected by fluorescence quantitative PCR.Results Compared with the control group,the systolic blood pressure of the tail artery in the model group were increased significantly before intervention and at the 1st,2nd,3rd and 4th weeks of intervention(P<0.05).Before intervention,the 24 h urine volume of the model,hydrochlorothiazide,acupuncture and sham acupuncture groups were decreased significantly(P<0.05).After intervention,the 24 h urine volume and urinary sodium excretion in the model group were significantly decreased(P<0.05);the expression levels of CCKBR protein and mRNA in renal tissue were significantly decreased(P<0.05);the expression levels of Na^(+)/K^(+)-ATPase protein and ATP1A1 mRNA were significantly increased(P<0.05);the glomerulus was mildly congested with a small amount of lymphocyte infiltration.Compared with the model group,the systolic blood pressure of the tail artery in the hydrochlorothiazide and the acupuncture groups were decreased significantly at the 2nd,3rd and 4th weeks of intervention(P<0.05);the 24 h urine volume and urinary sodium excretion in the hydrochlorothiazide and the acupuncture groups were significantly increased(P<0.05);the serum gastrin content and the expression levels of CCKBR protein and mRNA in renal tissue were significantly increased(P<0.05);the expression levels of Na^(+)/K^(+)-ATPase protein and ATP1A1 mRNA were significantly decreased(P<0.05);there were no obvious pathological changes in renal tissue.A small number of lymphocyte focal infiltration around blood vessels was observed in the kidney tissue of the sham acupuncture group.Conclusion Acupuncture can significantly reduce the tail artery systolic blood pressure of SHR,which may be related to its effect in increasing serum gastrin content and CCKBR expression,inhibiting sodium pump reabsorption,thus promoting urinary sodium excretion.