Responses of isolated canine airways to electric stimulation and acetylcholine.
Responses of isolated canine airways to electric stimulation and acetylcholine.
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离体犬气道对电刺激和乙酰胆碱的反应。
DOI：
10.1152/jappl.1978.45.5.690
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发表时间：
1978
期刊：
影响因子：
--
通讯作者：
J. Russell
中科院分区：
文献类型：
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作者：
J. Russell
在器官浴中研究了直径为5 mm和1.5mm的肺内气道的气管平滑肌条和螺旋条的收缩性。犬气道的乙酰胆碱（ACh）敏感性与其他物种非常相似，所有三种制剂的浓度-反应曲线也相似。电场刺激（ES）引起持续收缩，与豚鼠和人的气道相反，从未产生低于基线的舒张。阿托品拮抗的反应，ES和外源性ACh，而河豚毒素取消超最大ES的反应，而不改变ACh的浓度-反应曲线。因此，ES通过自主神经末梢释放神经递质收缩气道平滑肌，而外源性ACh直接作用于平滑肌细胞。ES产生的最大力与ACh产生的最大力的比值从气管到1.5 mm气道显著降低。后者的结果表明，无论是神经支配的气道平滑肌或平滑肌细胞间接触的类型，或两者兼而有之，取决于在气管支气管树的位置。
Contractility of tracheal smooth muscle strips and spiral strips of intrapulmonary airways 5 mm and 1.5 mm in diameter was studied in organ baths. Acetylcholine (ACh) sensitivity of canine airways closely resembled that of other species, and concentration-response curves for this drug were similar for all three preparations. Electric field stimulation (ES) elicited sustained contractions and, in contrast to guinea pig and human airways, never produced relaxations below the base line. Atropine antagonized the responses to both ES and exogenous ACh whereas tetrodotoxin abolished the response to supramaximal ES without altering ACh concentration-response curves. Thus, ES contracts airway smooth muscle via release of neurotransmitter from autonomic nerve endings whereas exogenous ACh acts directly on smooth muscle cells. The ratio of maximal force produced by ES to that produced by ACh decreased significantly from the trachea to the 1.5-mm airways. The latter result suggested that either the innervation of airway smooth muscle or the type of smooth muscle intercellular contacts, or both, vary depending on location within the tracheobronchial tree.