Maniscalco M, Sofia M, Smith A, Demoncheaux E A, Mormile M, Faraone S, Higenbottam T
Department of Respiratory Disease, University Federico II, Naples, Italy.
Respir Med. 1997 Jul;91(6):335-40. doi: 10.1016/s0954-6111(97)90059-7.
The role of nitric oxide (NO) as a bronchodilator has been studied in humans with controversial results. The aim of the present study was to investigate the role of endogenous NO on bronchial tone by studying whether nitric oxide synthase (NOS) inhibition with NGnitro-L-arginine-methyl-ester (L-NAME) influences basal bronchial tone, or potentiates methacholine-induced bronchoconstriction. In a preliminary experiment in five subjects, a significant reduction in exhaled NO was found after delivering L-NAME (15 mg in saline) (from 3.9 +/- 1.2 to 2.4 +/- 1.1 nmol min-1, P < 0.05). In nine healthy non-smokers, specific airway conductance (SGAW), as a measure of airway calibre, was recorded after delivering, in a double-blind, controlled vs. placebo fashion, both nebulized L-NAME and saline, at baseline and after methacholine-induced bronchoconstriction. There was no significant difference between the baseline SGAW values before and after delivering L-NAME (0.264 +/- 0.04 and 0.267 +/- 0.05 cm H2O-1 s-1, respectively). After pre-treatment with L-NAME, SGAW values during methacholine-induced bronchoconstriction were not different in comparison to values obtained after saline inhalation. It is concluded that decreased endogenous NO does not influence bronchial tone in healthy people, nor does it modify methacholine-induced bronchoconstriction.
一氧化氮（NO）作为支气管扩张剂的作用在人体中已有研究，但结果存在争议。本研究的目的是通过研究用NG-硝基-L-精氨酸甲酯（L-NAME）抑制一氧化氮合酶（NOS）是否会影响基础支气管张力，或增强乙酰甲胆碱诱导的支气管收缩，来探讨内源性NO在支气管张力中的作用。在一项针对5名受试者的初步实验中，给予L-NAME（15 mg溶于生理盐水）后，呼出的NO显著降低（从3.9±1.2降至2.4±1.1 nmol min-1，P<0.05）。在9名健康非吸烟者中，以双盲、对照与安慰剂对照的方式，在基线以及乙酰甲胆碱诱导的支气管收缩后，分别雾化吸入L-NAME和生理盐水，记录作为气道口径指标的比气道传导率（SGAW）。给予L-NAME前后的基线SGAW值之间无显著差异（分别为0.264±0.04和0.267±0.05 cm H2O-1 s-1）。用L-NAME预处理后，乙酰甲胆碱诱导的支气管收缩期间的SGAW值与吸入生理盐水后获得的值相比无差异。结论是，内源性NO减少不会影响健康人的支气管张力，也不会改变乙酰甲胆碱诱导的支气管收缩。
