[电针“足三里”（ST36）对功能性消化不良内脏高敏大鼠肥大细胞/TRPV1信号通路的影响]

[Influence of electroacupuncture of"Zusanli"(ST36)on mast cells/TRPV1 signaling pathway in visceral hypersensitivity rats with functional dyspepsia].

作者信息

Dong Jia-Zi, Rong Pei-Jing, Ma Tie-Ming, Wang Dan, Wang Xiao-Tong, Qiao Ye

机构信息

School of Acupuncture-moxibustion and Tuina, Liaoning University of Traditional Chinese Medicine, Liaoning 110847, China; Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing 100700.

Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing 100700.

出版信息

Zhen Ci Yan Jiu. 2022 Jul 25;47(7):592-7. doi: 10.13702/j.1000-0607.20210937.

DOI:10.13702/j.1000-0607.20210937

PMID:35880275

Abstract

OBJECTIVE

To explore the interventional mechanism of electroacupuncture (EA) of "Zusanli"(ST36)based on the involvement of mast cells/ transient receptor potential vanilloid type1 (TRPV1) signaling pathway in relieving visceral hypersensitivity in functional dyspepsia (FD) rats.

METHODS

Sixty SD rats (half male and half female, 10 days in age) were randomly divided into normal control, model, medication (ketotifen) and EA groups, with 15 rats in each group. The FD model was established by gavage of iodoacetamide combined with tail clamping (stress stimulation). Rats of the medication group received intraperitoneal injection of ketotifen (1 mg·kg·d) for 14 d, and those of the EA group received EA of ST36 for 20 min, once a day for 14 d. An air-balloon was inserted into the rat's stomach for recording changes of the intragastric pressure (mL/mm Hg) via a pressure transducer. The visceral hypersensitivity was assessed using abdominal withdrawal reflex (AWR) score and the number and degranulation of mast cells of gastric mucosa were observed using toluidine blue staining. The expression levels of TRPV1 and proteinase activated receptor 2 (PAR2) in the stomach were observed using immunofluorescence histochemistry and Western blot, separately, and the contents of SP and CGRP in the stomach detected using ELISA.

RESULTS

When the intragastric pressure was at 50, 60 and 70 mm Hg, the gastric compliance was significantly decreased (<0.01), and the levels of visceral sensitivity increased in the model group （<0.01）。 TRPV1 immunofluorescence tensity, expression of PAR2 and TRPV1 proteins, and contents of SP and CGRP in the stomach were considerably up-regulated in the model group compared with the normal control group (<0.01). In comparison with the model group, under intragastric pressure of 50，60 and 70 mm Hg, the gastric compliance was obviously increased, and the visceral hypersensitivity decreased in the EA group （<0.01,<0.05）. TRPV1 immunofluorescence intensity, expression levels of PAR2 and TRPV1 proteins, and the contents of SP and CGRP in the stomach were considerably down-regulated in both medication and EA groups compared with the model group (<0.01, <0.05). The therapeutic effect of EA was significantly superior to that of medication in up-regulating the gastric compliance （at 70 mm Hg）, and down-regulating the contents of SP and CGRP (<0.05). No significant differences were found between the EA and medication groups in up-regulating gastric compliance at intragastric pressure of 50 and 60 mm Hg, and in down-regulating the visceral sensitivity, TRPV1 fluorescence intensity, and expression of PAR2 and TRPV1 proteins (>0.05). Toluidine blue staining showed an apparent increase of mast cell number with obvious degranulation in the gastric mucosa of rats in the model group, which was milder in the EA and medication groups.

CONCLUSION

EA of ST36 can suppress visceral hypersensitivity and increase the gastric compliance in FD rats, which may be related with its effects in inhibiting the activation of gastric mast cells, and down-regulating the expression of gastric PAR2 and TRPV1 proteins and SP and CGRP contents.

摘要

目的

基于肥大细胞/瞬时受体电位香草酸亚型1（TRPV1）信号通路参与，探讨电针“足三里”（ST36）对功能性消化不良（FD）大鼠内脏高敏感性的干预机制。

方法

将60只SD大鼠（雌雄各半，10日龄）随机分为正常对照组、模型组、药物（酮替芬）组和电针组，每组15只。采用腹腔注射碘乙酰胺结合夹尾（应激刺激）法建立FD模型。药物组大鼠腹腔注射酮替芬（1mg·kg·d），连续14天；电针组大鼠针刺ST36，每次20分钟，每日1次，连续14天。将气囊插入大鼠胃内，通过压力传感器记录胃内压（mL/mm Hg）变化。采用腹部撤回反射（AWR）评分评估内脏高敏感性，用甲苯胺蓝染色观察胃黏膜肥大细胞数量及脱颗粒情况。分别采用免疫荧光组织化学和蛋白质免疫印迹法观察胃组织中TRPV1和蛋白酶激活受体2（PAR2）的表达水平，用酶联免疫吸附测定（ELISA）法检测胃组织中P物质（SP）和降钙素基因相关肽（CGRP）含量。

结果

当胃内压为50、60和70mmHg时，模型组胃顺应性显著降低（<0.01），内脏敏感性水平升高（<0.01）。与正常对照组比较，模型组胃组织中TRPV1免疫荧光强度、PAR2和TRPV1蛋白表达以及SP和CGRP含量均显著上调（<0.01）。与模型组比较，在胃内压为50、60和70mmHg时，电针组胃顺应性明显升高，内脏高敏感性降低（<0.01，<0.05）。药物组和电针组胃组织中TRPV1免疫荧光强度、PAR2和TRPV1蛋白表达水平以及SP和CGRP含量均较模型组显著下调（<0.01，<0.05）。在提高胃顺应性（70mmHg时）以及下调SP和CGRP含量方面，电针组疗效显著优于药物组（<0.05）。在胃内压为50和60mmHg时提高胃顺应性以及下调内脏敏感性、TRPV1荧光强度和PAR2及TRPV1蛋白表达方面，电针组与药物组比较差异无统计学意义（>0.05）。甲苯胺蓝染色显示，模型组大鼠胃黏膜肥大细胞数量明显增多，脱颗粒明显，电针组和药物组则较轻。