Delpierre S, Orehek J, Beaupré A, Velardocchio J M, Fornaris M, Grimaud C
Bull Eur Physiopathol Respir. 1983 Sep-Oct;19(5):489-93.
To dissociate airway stimulation from airway response, a segment of the cervical trachea was isolated from the rest of the bronchial tree in 15 anesthetized dogs; nerve and blood supplies of the segment were preserved. Patency of the intrathoracic airways was assessed with lung resistance (RL) measurements. When doses of aerosolized histamine (His), acetylcholine (ACh) and serotonin (Ser) causing comparable increases in RL were delivered into the intrathoracic airways, concomitant increases in pressure were recorded in the tracheal segment (indicating constriction) with His being the most effective. When the hypoxemia accompanying His- and ACh-induced bronchoconstriction was prevented by inhaling an air-oxygen mixture, the tracheal response persisted (2 dogs). Vagotomy decreased the RL response to His, ACh and Ser and abolished tracheal response (13 dogs). The tracheal response was still abolished when larger doses of His and ACh were given in order to induce an increase in RL similar to that observed before vagotomy (7 dogs). These data suggest the existence of a positive feed-back mechanism in the airways, pharmacological bronchoconstriction causing vagally mediated reflex bronchoconstriction. Direct stimulation of lung irritant receptors by histamine may explain the larger degree of reflex bronchoconstriction observed with this agent.
为了区分气道刺激与气道反应，在15只麻醉犬中，将一段颈段气管与支气管树的其余部分分离；保留该段气管的神经和血液供应。通过测量肺阻力（RL）评估胸内气道的通畅性。当将引起RL可比增加的雾化组胺（His）、乙酰胆碱（ACh）和5-羟色胺（Ser）剂量输送到胸内气道时，气管段记录到压力随之增加（表明收缩），其中His最为有效。当通过吸入空气-氧气混合物预防His和ACh诱导的支气管收缩伴随的低氧血症时，气管反应持续存在（2只犬）。迷走神经切断术降低了对His、ACh和Ser的RL反应，并消除了气管反应（13只犬）。当给予更大剂量的His和ACh以诱导类似于迷走神经切断术前观察到的RL增加时，气管反应仍然被消除（7只犬）。这些数据表明气道中存在正反馈机制，药理学支气管收缩导致迷走神经介导的反射性支气管收缩。组胺对肺刺激性感受器的直接刺激可能解释了用该药物观察到的更大程度的反射性支气管收缩。
