Brown R H, Zerhouni E A, Hirshman C A
Department of Anesthesiology, Johns Hopkins Medical Institutions, Baltimore, Maryland 21205.
Am J Respir Crit Care Med. 1994 Jul;150(1):233-7. doi: 10.1164/ajrccm.150.1.8025755.
Using high-resolution CT (HRCT), which measures changes in innervated airways greater than 1 mm in diameter, we compared the ability of nitric oxide (NO) to dilate airways preconstricted with histamine and methacholine in five anesthetized dogs. After the airways were preconstricted, NO was inhaled in concentrations of 100, 200, and 400 ppm. Additionally, histamine was given with and without atropine and methylene blue. Data were analyzed by one-way analysis of variance. Histamine and methacholine decreased airway area to a similar extent: 60 +/- 3% (mean +/- SEM) and 63 +/- 3% of control, respectively (p = 0.85). Atropine completely reversed the histamine-induced constriction (255 +/- 19%). NO also completely reversed histamine-induced airway constriction in a dose-related fashion. The airway area went from 60 +/- 3% during histamine infusion to 85 +/- 5, 102 +/- 5, and 111 +/- 10% of control, respectively (p < 0.01), after doses of 100, 200, and 400 ppm NO. Methylene blue partially inhibited the reversal by 200 ppm NO of histamine-induced constriction. In contrast, NO only partially reversed methacholine-induced constriction. NO at 100, 200, and 400 ppm partially attenuated the methacholine-induced airway constriction. Airway area went from 63 +/- 3 to 67 +/- 3, 75 +/- 3, and 75 +/- 2% of control, respectively (p < 0.01). We conclude that NO relaxes canine conducting airways by indirect mechanisms as well as by directly relaxing the airway smooth muscle.
我们使用高分辨率计算机断层扫描（HRCT）来测量直径大于1毫米的受神经支配气道的变化，比较了一氧化氮（NO）对五只麻醉犬中由组胺和乙酰甲胆碱预收缩气道的舒张能力。气道预收缩后，吸入浓度为100、200和400 ppm的NO。此外，分别在有和没有阿托品及亚甲蓝的情况下给予组胺。数据采用单因素方差分析。组胺和乙酰甲胆碱使气道面积减少的程度相似：分别为对照的60±3%（平均值±标准误）和63±3%（p = 0.85）。阿托品完全逆转了组胺诱导的收缩（255±19%）。NO也以剂量相关的方式完全逆转了组胺诱导的气道收缩。在给予100、200和400 ppm NO后，气道面积分别从组胺输注期间的60±3%恢复到对照的85±5%、102±5%和111±10%（p < 0.01）。亚甲蓝部分抑制了200 ppm NO对组胺诱导收缩的逆转作用。相比之下，NO仅部分逆转了乙酰甲胆碱诱导的收缩。100、200和400 ppm的NO部分减轻了乙酰甲胆碱诱导的气道收缩。气道面积分别从对照的63±3%变为67±3%、75±3%和75±2%（p < 0.01）。我们得出结论，NO通过间接机制以及直接舒张气道平滑肌来舒张犬的传导气道。
