臭氧暴露的肺功能反应与辣椒素咳嗽敏感性的关系
2013/10/11
摘要
背景：人类激发试验研究显示臭氧暴露导致的肺损伤有相当大的个体差异。
目的：先前的研究已证实了神经通路的效应调整机制，本文旨在研究C类感觉神经纤维反应与臭氧触发反应模式间的相关性。
方法：通过辣椒素单一呼吸剂量-效应方法评估咳嗽反射阈值来反应C-纤维的敏感性。分别记录诱发2次和5次及以上咳嗽的辣椒素触发浓度 C2和C5。基于间歇运动协议内容，16例健康受试者随机暴露的臭氧浓度为240 ppb和40ppb(假暴露)。臭氧反应定义为第1秒末用力呼气量(FEV1)下降超过5%。
结果：基于二分分类法，臭氧反应增强受试者的咳嗽临界值低于无反应者(C2, p = 0.035; C5, p = 0.086)。总之，本研究证实辣椒素敏感性与臭氧触发导致的FEV1、呼气流量峰值和肺活量达50%时最大呼气流速的改变具有相关性，但与特异性气道阻力间与显著相关性。
结论：本研究结果显示辣椒素激发试验可能对描绘受试者吸入刺激物增强肺功能反应是有帮助的。
（刘国梁 审校）
Inhal Toxicol. 2013 Aug;25(10):569-76. doi: 10.3109/08958378.2013.812699. Epub 2013 Aug 6.
Relationship of pulmonary function response to ozone exposure and capsaicin cough sensitivity.
Hoffmeyer F, Sucker K, Monsé C, Berresheim H, Rosenkranz N, Jettkant B, Beine A, Brüning T, Bünger J.
Abstract
Abstract Context: Challenge studies in humans have shown considerable interindividual variability in pulmonary impairment across ozone exposure.
Objective: Since previous results suggested effect modulation by neural mechanism, we investigated sensory C-fiber reactivity in relationship to ozone-triggered response pattern.
Methods: Cough reflex thresholds reflecting C-fiber sensitivity were evaluated by capsaicin single breath dose-response method. Capsaicin concentrations triggering, respectively, two and five or more coughs (C2, C5) were recorded. Sixteen healthy subjects were randomly exposed in an intermittent exercise protocol to ozone concentrations of 240 and 40 ppb (sham exposure). Ozone responsiveness was defined by a decrease in forced expiratory volume in 1 s (FEV1) of more than 5%.
Results: Based on a dichotomous classification, subjects with enhanced reactivity to ozone had lower cough thresholds than non-responders (C2, p = 0.035; C5, p = 0.086). Over all, we could demonstrate relationships between capsaicin sensitivity and ozone-triggered changes in FEV1, peak expiratory flow and maximal expiratory flow at 50% vital capacity but not in specific airway resistance.
Conclusion: Our results suggest that capsaicin challenge tests might be useful to characterize subjects with enhanced pulmonary function response towards inhalant irritants.
Inhal Toxicol. 2013 Aug;25(10):569-76. doi: 10.3109/08958378.2013.812699. Epub 2013 Aug 6.
