Abraham W M, Kim C S, King M M, Oliver W, Yerger L
Arch Environ Health. 1982 Jan-Feb;37(1):36-40.
The airway effect of a 4-hr exposure (via a Plexiglas hood) to 1.6 ppm nitric acid vapor were evaluated in seven normal and seven allergic sheep, i.e., animals that have a history of reacting with bronchospasm to inhalation challenge with Ascaris suum antigen. The nitric acid vapor was generated by ultrasonic nebulization of a 2% nitric acid solution. Airway effects were assessed by measuring the change in specific pulmonary flow resistance before and after a standard inhalation challenge with 2.5% carbachol aerosol. Nitric acid exposure did not produce bronchoconstriction in either group. Pre-exposure increases in specific pulmonary flow resistance after carbachol inhalation were 68% (SD +/- 13%) and 82% (SD +/- 35%) for the normal and allergic sheep, respectively. Within 24 hr, the largest post exposure increased in specific pulmonary flow resistance for the normal and allergic sheep were 108% [SD +/- 51% (P less than .06)] and 175% [SD +/- 87% (P less than .02)], respectively. We conclude that a short-term exposure to nitric acid vapor at levels below the industrial threshold limit (2 ppm), produces airway hyperreactivity to aerosolized carbachol in allergic sheep.
在7只正常绵羊和7只过敏绵羊（即有因吸入猪蛔虫抗原引发支气管痉挛反应病史的动物）中，评估了通过有机玻璃面罩4小时暴露于1.6 ppm硝酸蒸汽的气道效应。硝酸蒸汽通过2%硝酸溶液的超声雾化产生。通过测量用2.5%卡巴胆碱气雾剂进行标准吸入激发前后比肺流阻的变化来评估气道效应。硝酸暴露在两组中均未产生支气管收缩。对于正常绵羊和过敏绵羊，吸入卡巴胆碱后暴露前比肺流阻的增加分别为68%（标准差±13%）和82%（标准差±35%）。在24小时内，正常绵羊和过敏绵羊暴露后比肺流阻的最大增加分别为108%[标准差±51%（P<0.06）]和175%[标准差±87%（P<0.02）]。我们得出结论，在低于工业阈限值（2 ppm）的水平下短期暴露于硝酸蒸汽，会使过敏绵羊对雾化卡巴胆碱产生气道高反应性。
