Reflex responses to capsaicin: intravenous, aerosol, and intratracheal administration.
Reflex responses to capsaicin: intravenous, aerosol, and intratracheal administration.
复制标题
对辣椒素的反射反应：静脉注射、气雾剂和气管内给药。
DOI：
10.1152/jappl.1989.67.4.1428
复制
发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Mathew,OP
中科院分区：
文献类型：
--
作者：
Palecek,F;Sant'Ambrogio,G;Sant'Ambrogio,FB;Mathew,OP
静脉注射辣椒素可能是通过刺激“肺C纤维”来激发“肺化学反射”（呼吸暂停、心动过缓和低血压）。“本研究旨在确定气管支气管C纤维是否在上述反射反应中发挥作用。我们比较了麻醉犬（n = 17）和大鼠（n = 17）静脉注射、气雾剂给药和胸内气管局部给药的辣椒素的作用。我们测量了食道压力、声门下压力和动脉压力以及腹部肌肉肌电图。在两只犬中，所有三种给药途径下辣椒素引起的呼气持续时间变化[（TE），测量为TE试验与TE对照的比值，平均值+/- SD]相似（静脉注射，7.9 +/- 4.6;气雾剂，5.5 +/- 3.1;局部进入胸内气管，7.1 +/- 4.8）和大鼠（静脉注射，22.6 +/- 10.3;气雾剂，11.1 +/- 8.2;局部进入胸内气管，21.6 +/- 4.6）。喉阻力增加是大鼠中的常见结果，但在犬中不太常见。所有三种给药途径均发生心血管反应（包括心动过缓和低血压），但延迟时间长于呼吸反应。辣椒素滴入犬胸外气管（n = 7）也诱导了定性相似的心肺反应。我们的结论是：1）辣椒素敏感受体可从肺循环和气道腔和2）传入，即使在气管支气管树的肺外部分，可以发挥作用的反射反应，管腔内辣椒素。
Intravenous capsaicin elicits the "pulmonary chemoreflex" (apnea, bradycardia, and hypotension) presumably through the stimulation of "pulmonary C-fibers." The present study was designed to ascertain whether tracheobronchial C-fibers play a role in the above reflex response. We compared the effects of capsaicin injected intravenously, administered as an aerosol, and administered topically into the intrathoracic trachea in anesthetized dogs (n = 17) and rats (n = 17). We measured esophageal, subglottic, and arterial pressures together with abdominal muscle electromyogram. Changes in expiratory duration [(TE), measured as the ratio TEtest to TEcontrol, mean +/- SD] due to capsaicin were similar with all three routes of administration in both dogs (intravenous, 7.9 +/- 4.6; aerosol, 5.5 +/- 3.1; topically into intrathoracic trachea, 7.1 +/- 4.8) and rats (intravenous, 22.6 +/- 10.3; aerosol, 11.1 +/- 8.2; topically into intrathoracic trachea, 21.6 +/- 4.6). An increase in laryngeal resistance was a constant finding in the rat, but it was less frequent in the dog. Cardiovascular responses consisting of bradycardia and hypotension occurred with all three routes of administration but had longer delays than the respiratory responses. Capsaicin instillation into the extrathoracic trachea in dogs (n = 7) also induced qualitatively similar cardiorespiratory responses. We conclude that 1) capsaicin-sensitive receptors are accessible from both the pulmonary circulation and the airway lumen and 2) afferents, even in the extrapulmonary portion of the tracheobronchial tree, can play a role in the reflex responses to intraluminal capsaicin.