Horstman D, Roger L J, Kehrl H, Hazucha M
Toxicol Ind Health. 1986 Sep;2(3):289-98. doi: 10.1177/074823378600200307.
The purpose of this study was to describe for asthmatic subjects the distribution of individual bronchial sensitivity to sulfur dioxide (SO2). Subjects were nonsmoking male asthmatics (n = 27) who were sensitive to inhaled methacholine. None of the subjects used corticosteroids or cromolyn sodium. Oral medications were withheld for 48 hr, inhaled medications for 12 hr prior to all testing. Each subject participated in four separate randomly ordered 10 min exposures to 0.00, 0.25, 0.50 and 1.00 ppm SO2 at 26 degrees C, 70% relative humidity. During exposures, subjects breathed naturally and performed moderate exercise (VE, normalized for body surface area = 21 1/m2 X min). Before and 3 min after exposure, specific airway resistance (SRaw) was measured by body plethysmography. Those subjects whose SRaw was not doubled by exposure to 1.00 ppm were also exposed to 2.00 ppm SO2. Dose response curves (relative change in SRaw, corrected for change in clean air vs SO2 concentration) were constructed for each subject. Bronchial sensitivity to SO2 [PC(SO2)], defined as the concentration of SO2 which provoked an increase in SRaw 100% greater than the response to clean air, was determined. Substantial variability in sensitivity was observed: for 23 subjects, PC(SO2) ranged between 0.28 and 1.90 ppm, while for the remaining 4 subjects, it was greater than 2.00 ppm SO2. The median PC(SO2) was 0.75 ppm SO2, and 6 subjects had a PC(SO2) of less than 0.50 ppm. PC(SO2) was not related (r = 0.31) to airway sensitivity to methacholine.
本研究的目的是描述哮喘患者个体对二氧化硫（SO₂）的支气管敏感性分布情况。研究对象为不吸烟的男性哮喘患者（n = 27），他们对吸入的乙酰甲胆碱敏感。所有受试者均未使用皮质类固醇或色甘酸钠。在所有测试前，口服药物停用48小时，吸入药物停用12小时。每位受试者在26℃、相对湿度70%的条件下，分别以随机顺序参加四次10分钟的暴露试验，暴露于0.00、0.25、0.50和1.00 ppm的SO₂环境中。暴露期间，受试者自然呼吸并进行适度运动（每分钟每平方米体表面积的分钟通气量（VE）= 21升）。暴露前和暴露后3分钟，通过体容积描记法测量比气道阻力（SRaw）。那些暴露于1.00 ppm SO₂后SRaw未翻倍的受试者，还会暴露于2.00 ppm SO₂环境中。为每位受试者构建剂量反应曲线（SRaw的相对变化，根据清洁空气与SO₂浓度变化进行校正）。确定了支气管对SO₂的敏感性[PC(SO₂)]，即引起SRaw增加幅度比清洁空气反应大100%的SO₂浓度。观察到敏感性存在很大差异：23名受试者的PC(SO₂)在0.28至1.90 ppm之间，而其余4名受试者的PC(SO₂)大于2.00 ppm SO₂。PC(SO₂)的中位数为0.75 ppm SO₂，6名受试者的PC(SO₂)小于0.50 ppm。PC(SO₂)与气道对乙酰甲胆碱的敏感性无关（r = 0.31）。
