Schertel E R, Adams L, Schneider D A, Smith K S, Green J F
J Appl Physiol (1985). 1986 Sep;61(3):1237-40. doi: 10.1152/jappl.1986.61.3.1237.
Recently Green et al. (J. Appl. Physiol. 57:562-567, 1984) reported that pulmonary C-fibers initiate the prompt apnea evoked by pulmonary arterial injections of capsaicin; however, their role in the subsequent rapid shallow breathing of the pulmonary chemoreflex is still in dispute. To determine whether this reflex tachypnea is triggered by pulmonary C-fibers rather than by afferents further downstream, we separately perfused the pulmonary and systemic circulations in dogs anesthetized with either halothane or alpha-chloralose as the lungs were ventilated with a servo-controlled ventilator driven by phrenic nerve activity. Injection of capsaicin (10 micrograms/kg) into the pulmonary artery of the isolated pulmonary circulation evoked an immediate apnea followed by rapid shallow breathing. Injection of the same dose of capsaicin into the left atrium of the isolated pulmonary circulation had no effect. By contrast, when capsaicin was administered at a slower rate into the pulmonary artery (10-20 micrograms X kg-1 X min-1) rapid shallow breathing occurred but without apnea. Our results are consistent with the hypothesis that in spontaneously breathing animals, stimulation of pulmonary C-fibers can evoke rapid shallow breathing.
最近，格林等人（《应用生理学杂志》57:562 - 567，1984年）报道，肺C纤维引发肺动脉注射辣椒素所诱发的迅速呼吸暂停；然而，它们在随后肺化学反射的快速浅呼吸中的作用仍存在争议。为了确定这种反射性呼吸急促是由肺C纤维触发，还是由更下游的传入神经触发，我们在用氟烷或α - 氯醛糖麻醉的狗身上，当用由膈神经活动驱动的伺服控制呼吸机对肺进行通气时，分别灌注肺循环和体循环。向孤立肺循环的肺动脉注射辣椒素（10微克/千克）会立即引发呼吸暂停，随后是快速浅呼吸。向孤立肺循环的左心房注射相同剂量的辣椒素则没有效果。相比之下，当以较慢速度（10 - 20微克×千克⁻¹×分钟⁻¹）向肺动脉注射辣椒素时，会出现快速浅呼吸，但没有呼吸暂停。我们的结果与以下假设一致，即在自主呼吸的动物中，刺激肺C纤维可诱发快速浅呼吸。
