Influence of ventrolateral surface of medulla on reflex tracheal constriction.
Influence of ventrolateral surface of medulla on reflex tracheal constriction.
复制标题
延髓腹外侧表面对反射性气管收缩的影响。
DOI：
10.1152/jappl.1986.61.2.791
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Cherniack,NS
中科院分区：
文献类型：
--
作者：
Haxhiu,MA;DealJr,EC;Norcia,MP;vanLunteren,E;Mitra,J;Cherniack,NS
为了评估位于延髓腹外侧面附近的浅层结构在机械或化学刺激呼吸道和肺感受器时发生的气管平滑肌反射性收缩中的作用，在α-氯醛糖麻醉、瘫痪和人工呼吸的猫身上进行了实验。旁路段气管内的压力变化被用来作为平滑肌张力改变的指标。观察了中央降温或延髓腹面局部应用利多卡因对气管对机械刺激和化学刺激呼吸道受体的反应的影响。阿托品可阻断机械刺激隆突或雾化组胺引起的气管收缩，表明这种反应是通过迷走神经通路实现的。中度冷却中间区域(20摄氏度)或局部应用利多卡因可显著降低对呼吸道感受器机械激活的收缩反应。此外，当气管被组胺收缩时，冷却中间区域显著减少增加的气管张力，而复温使气管张力恢复到以前的水平。这些结果表明，在本实验条件下，延髓腹侧表面通过肺内受体的输入对气管的收缩和副交感神经流出向气道平滑肌的调节起着重要作用。
To assess the role of structures located superficially near the ventrolateral surface of the medulla on the reflex constriction of tracheal smooth muscle that occurs when airway and pulmonary receptors are stimulated mechanically or chemically, experiments were conducted in alpha-chloralose-anesthetized, paralyzed, and artificially ventilated cats. Pressure changes within a bypassed segment of the trachea were used as an index of alterations smooth muscle tone. The effects of focal cooling of the intermediate areas or topically applied lidocaine on the ventral surface of the medulla on the response of the trachea to mechanical and chemical stimulation of airway receptors were examined. Atropine abolished tracheal constriction induced by mechanical stimulation of the carina or aerosolized histamine, showing that the responses were mediated over vagal pathways. Moderate cooling of the intermediate area (20 degrees C) or local application of lidocaine significantly decreased the tracheal constrictive response to mechanical activation of airway receptors. Furthermore, when the trachea was constricted by histamine, cooling of the intermediate area significantly diminished the increased tracheal tone, whereas rewarming restored tracheal tone to the previous level. These findings suggest that under the conditions of the experiments the ventral surface of the medulla plays an important role in constriction of the trachea by inputs from intrapulmonary receptors and in the modulation of parasympathetic outflow to airway smooth muscle.