Capsaicin-sensitive and -insensitive vagal bronchopulmonary C-fibres in the mouse
Capsaicin-sensitive and -insensitive vagal bronchopulmonary C-fibres in the mouse
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DOI：
10.1113/jphysiol.2003.042028
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发表时间：
2003-09-15
影响因子：
5.5
通讯作者：
Undem, BJ
中科院分区：
文献类型：
--
作者：
Kollarik, M;Dinh, QT;Undem, BJ
我们研制了一种气管灌注（35- 37 ℃）神经肺标本，用于研究小鼠支气管肺传入神经活动。从位于颈静脉结状神经节复合体（JNC）中的迷走感觉神经元进行细胞外记录，并在肺中确定感受野。迷走神经复合动作电位的分析表明，小鼠迷走神经C纤维传导速度范围为0.3至1.5 m s（-1）。共研究了83支支气管肺炎C-纤维。支气管肺动脉C纤维对香草酸受体1（VR 1）激动剂辣椒素的敏感性取决于传导速度。因此，传导速度在0.3和0.7 m·s（-1）之间的C-纤维对辣椒素（1 μ m）有反应，而传导速度在0.7和1.5 m·s（-1）之间的C-纤维对辣椒素不敏感。类似地，缓激肽（1 μ M）仅兴奋传导速度< 0.7 m s（-1）的C纤维。β（1）受体激动剂[des-Arg（9）]缓激肽（1 μ m）不能模拟缓激肽的反应，缓激肽β（2）受体拮抗剂HOE 140（1 μ m）可消除缓激肽的反应。腺苷5 '-三磷酸（ATP，30 μ M）激活C-纤维的传导速度无关。该反应由选择性P2 X激动剂α，β-亚甲基-腺苷5 '-三磷酸（30，am）模拟。与电生理学一致，形态学分析显示，与C纤维细胞体一致的肺特异性小直径（< 20 μ m）JNC神经元中仅约40%显示VRI免疫反应性。本文介绍了一种简便的小鼠支气管肺纤维C-纤维的体外研究方法。结果表明，小鼠肺中的C-纤维是不均匀的，但可以细分为辣椒素敏感和辣椒素不敏感的表型。
We developed an isolated tracheally perfused (35-37degreesC) nerve-lung preparation for the study of bronchopulmonary afferent nerve activity in the mouse. Extracellular recordings were made from the vagal sensory neurons located in the jugular-nodose ganglia complex (JNC) with identified receptive fields in the lungs. Analysis of the vagal compound action potential revealed that the mouse vagal C-fibre conduction velocities range from 0.3 to 1.5 m s(-1). A total of 83 bronchopulmonary C-fibres were studied. The sensitivity of the bronchopulmonary C-fibres to the vanilloid receptor 1 (VR1) agonist capsaicin was dependent on conduction velocity. Thus C-fibres with conduction velocities between 0.3 and 0.7 m s(-1) responded to capsaicin (I ym) while C-fibres with conduction velocities between 0.7 and 1.5 m s(-1) were capsaicin insensitive. Similarly, bradykinin (1muM) excited only those C-fibres with conduction velocities < 0.7 m s(-1). The response to bradykinin was not mimicked by the beta(1) receptor agonist [des-Arg(9)]bradykinin (1 mum) and was abolished by the bradykinin beta(2) receptor antagonist HOE 140 (1 mum). Adenosine 5'-triphosphate (ATP, 30 muM) activated the C-fibres irrespective of the conduction velocities. This response was mimicked by the selective P2X agonist alpha,beta-methylene-adenosine 5'-triphosphate (30,am). Consistent with the electrophysiology, morphological analysis revealed that only similar to40 % of the lung-specific small diameter (< 20 ym) JNC neurons consistent with the C-fibre cell bodies display VRI immunoreactivity. This study describes a convenient in vitro method for the study of mouse bronchopulmonary C-fibres. The results indicate that C-fibres in the mouse lungs are not homogeneous, but can be subclassified into capsaicin-sensitive and capsaicin-insensitive phenotypes.