Davis B, Roberts A M, Coleridge H M, Coleridge J C
J Appl Physiol Respir Environ Exerc Physiol. 1982 Oct;53(4):985-91. doi: 10.1152/jappl.1982.53.4.985.
We examined the effect of stimulating bronchial C-fibers on tracheal submucosal gland secretion in anesthetized dogs with open chest and lungs ventilated through the lower trachea. We opened the upper trachea in the midline, retracted the cut edges, and sprayed powdered tantalum onto the exposed mucosa. Secretions from the ducts of submucosal glands caused elevations (hillocks) in the tantalum layer, which were viewed through a microscope and recorded on videotape with a television camera. We counted the hillocks (greater than 0.2 mm diam) in an area of mucosa (1.2 cm2) before and after injecting capsaicin (3 micrograms) into a bronchial artery to stimulate bronchial C-fibers. In the minute before capsaicin was injected 7 +/- 2 (mean +/- SE; n = 20) hillocks appeared and in the minute after 40 +/- 2 hillocks. Bradykinin (1.5 micrograms) had similar effects. Secretion was accompanied by contraction of the trachealis muscle. Effects were abolished by cooling (0 degree C) or cutting the vagus nerves. Since capsaicin and bradykinin stimulate bronchial C-fibers selectively when injected in these small doses, we conclude that bronchial C-fibers furnish the afferent arm of an airway secretory reflex.
我们研究了刺激支气管C纤维对开胸且经下气管通气的麻醉犬气管黏膜下腺分泌的影响。我们在气管中线处打开上段气管，将切开边缘牵开，并将钽粉喷洒在暴露的黏膜上。黏膜下腺导管的分泌物使钽层出现隆起（小丘），通过显微镜观察并用电视摄像机记录在录像带上。在向支气管动脉注射辣椒素（3微克）以刺激支气管C纤维之前和之后，我们对黏膜区域（1.2平方厘米）内的小丘（直径大于0.2毫米）进行计数。在注射辣椒素前1分钟出现7±2（平均值±标准误；n = 20）个小丘，注射后1分钟出现40±2个小丘。缓激肽（1.5微克）有类似作用。分泌伴有气管肌收缩。冷却（0摄氏度）或切断迷走神经可消除这些作用。由于以这些小剂量注射时辣椒素和缓激肽可选择性地刺激支气管C纤维，我们得出结论，支气管C纤维构成气道分泌反射的传入支。
