Kharitonov S A, O'Connor B J, Evans D J, Barnes P J
Department of Thoracic Medicine, National Heart and Lung Institute, London, United Kingdom.
Am J Respir Crit Care Med. 1995 Jun;151(6):1894-9. doi: 10.1164/ajrccm.151.6.7767537.
The concentration of nitric oxide (NO) is increased in the exhaled air of asthmatic patients and may reflect cytokine-mediated inflammation in the airways. We investigated whether allergen-induced inflammation causes an elevation in the level of exhaled NO. Of 25 patients who underwent allergen challenge, 16 developed dual early and late responses, whereas eight had a single early response. In the patients with a dual response, the maximal fall in FEV1 during the late response was 26.8 +/- 4.2% at 9 h and there was a significant increase in the level of exhaled NO (maximal increase of 59.4 +/- 9.8%) 10 h after challenge. There was a significant relationship between the size of the late response and the increase in exhaled NO (r = 0.75, p < 0.01). In patients who have a single early response, there was no significant increase in exhaled NO, with the exception of a single time point at 21 h. In five patients given a control challenge with methacholine there was no change in exhaled NO. There was no increase in exhaled NO after inhaled histamine in any of the patient groups. We conclude that the late asthmatic response to allergen is associated with elevated exhaled NO concentrations and that this provides further evidence that exhaled NO may reflect allergic inflammation in asthmatic airways, and may be a useful marker in monitoring asthma and its response to anti-inflammatory treatments. Whether endogenously produced NO plays a pathophysiologic role in the late response remains to be determined.
哮喘患者呼出气体中一氧化氮（NO）的浓度升高，这可能反映了气道中细胞因子介导的炎症。我们研究了变应原诱导的炎症是否会导致呼出NO水平升高。在25例接受变应原激发试验的患者中，16例出现了早期和晚期双重反应，而8例只有单一的早期反应。在出现双重反应的患者中，晚期反应时FEV1在9小时的最大下降为26.8±4.2%，激发试验后10小时呼出NO水平显著升高（最大升高59.4±9.8%）。晚期反应的程度与呼出NO的增加之间存在显著相关性（r = 0.75，p < 0.01）。在只有单一早期反应的患者中，除了21小时的一个时间点外，呼出NO没有显著增加。在5例接受乙酰甲胆碱对照激发试验的患者中，呼出NO没有变化。在任何患者组中，吸入组胺后呼出NO均未增加。我们得出结论，哮喘对变应原的晚期反应与呼出NO浓度升高有关，这进一步证明呼出NO可能反映哮喘气道中的变应性炎症，并且可能是监测哮喘及其对抗炎治疗反应的有用标志物。内源性产生的NO在晚期反应中是否发挥病理生理作用仍有待确定。
