CGRP/ASIC3参与大鼠食道扩张内脏痛模型中背根神经节神经元高敏感机制的研究  

Mechanism of CGRP/ASIC3 participating in the hypersensitivity of DRG neurons in the rat model of esophageal dilatation visceral pain

作　　者：许草 顾勇[2] 石亚婷 汪桂祥 牛小平[3] XU Cao;GU Yong;SHI Yating;WANG Guixiang;NIU Xiaoping(Graduate School,Wannan Medical College,Wuhu 241002,China;Department of Pediatrics,Yijishan Hospital,Wannan Medical College;Department of Gastroenterology,Yijishan Hospital,Wannan Medical College)

机构地区：[1]皖南医学院研究生院,安徽芜湖241002 [2]皖南医学院弋矶山医院儿科 [3]皖南医学院弋矶山医院消化内科

出　　处：《沈阳医学院学报》2023年第1期19-23,29,共6页Journal of Shenyang Medical College

基　　金：安徽高校自然科学研究项目(No.KJ2020A0600)。

摘　　要：目的:探讨降钙素基因相关肽(CGRP)和酸敏感离子通道3(ASIC3)参与大鼠食道扩张(ED)内脏痛模型中脊髓背根神经节(DRG)神经元高敏感发生的机制。方法:将50只健康雄性SD大鼠随机分为实验组(n=30)和对照组(n=20)。腹腔麻醉50只SD大鼠,暴露大鼠食管下段,利用PE-240管对实验组大鼠的胸段食管进行1 h重复ED刺激,对照组则不予处理。分离并培养50只大鼠胸段脊髓DRG神经元,根据实验组培养液中有无加入CGRP拮抗剂(CGRP8-37)将其进一步分为ED组(n=15)和ED+CGRP8-37组(n=15)。采用全细胞膜片钳技术记录DRG神经元动作电位及ASIC3电流变化;免疫荧光法检测DRG神经元中CGRP、ASIC3的表达定位;逆转录实时聚合酶链反应(qRT-PCR)法检测CGRP与ASIC3 mRNA表达;Western blot法检测CGRP与ASIC3蛋白表达。结果:ED组DRG神经元动作电位数较对照组显著增加(P<0.01);免疫荧光结果示CGRP与ASIC3在DRG神经元中存在共表达;与对照组比较,ED组CGRP与ASIC3的mRNA、蛋白水平显著上调(P<0.01);且CGRP的mRNA、蛋白表达与ASIC3的mRNA、蛋白表达均呈正相关(r分别为0.833、0.981,P<0.01);ED组和ED+CGRP8-37组ASIC3电流较对照组显著增加(P<0.01),ED+CGRP8-37组ASIC3电流较ED组明显减少(P<0.01)。结论:CGRP和ASIC3共同参与了ED模型中DRG神经元的超敏反应,CGRP参与调节ASIC3电流变化可能是DRG神经元高敏感发生的重要机制之一。Objective:To investigate the mechanism of calcitonin gene-related peptide(CGRP)and acid sensitive ion channel 3(ASIC3)involved in the hypersensitivity of spinal dorsal root ganglion(DRG)neurons in the rat model of esophageal dilation(ED)visceral pain.Methods:A total of 50 healthy male SD rats were randomly divided into the experimental group(n=30)and the control group(n=20).SD rats were anesthetized intraperitoneally to expose the lower esophagus.The thoracic esophagus of rats in the experimental group was repeatedly stimulated with PE-240 tube for 1 h,while the control group was not treated.DRG neurons in thoracic spinal cord of 50 rats were isolated and cultured.According to whether CGRP antagonist(CGRP8-37)was added to the culture medium of the experimental group,they were further divided into ED group(n=15)and ED+CGRP8-37 group(n=15).Whole cell patch clamp technique was used to record the changes of action potential and ASIC3 current of DRG neurons.The expression and localization of CGRP and ASIC3 in DRG neurons were detected by immunofluorescence.The mRNA and protein expressions of CGRP and ASIC3 were detected by qRT-PCR and Western blot,respectively.Results:The number of action potentials of DRG neurons in ED group was significantly higher than that in the control group(P<0.01).Immunofluorescence results showed that CGRP and ASIC3 were co-expressed in DRG neurons.Compared with the control group,the mRNA and protein levels of CGRP and ASIC3 in ED group were significantly up-regulated(P<0.01).The expression of CGRP mRNA and protein was positively correlated with the expression of ASIC3 mRNA and protein(r=0.833 and 0.981,respectively,P<0.01).Compared with the control group,ASIC3 current in ED group and ED+CGRP8-37 group increased significantly(P<0.01),and ASIC3 current in ED+CGRP8-37 group decreased significantly compared with ED group(P<0.01).Conclusions:CGRP and ASIC3 jointly participate in the hypersensitivity of DRG neurons in the ED model.The regulation of ASIC3 current by CGRP may be one of the important

关 键 词：酸敏感离子通道3 降钙素基因相关肽 脊髓背根神经节 食管扩张 内脏高敏感 

分 类 号：R573.9[医药卫生—消化系统]