Gauvreau G M, Ronnen G M, Watson R M, O'Byrne P M
Asthma Research Group, St. Joseph's Hospital and the Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
Am J Respir Crit Care Med. 2000 Oct;162(4 Pt 1):1302-7. doi: 10.1164/ajrccm.162.4.2001054.
The cysteinyl leukotrienes (LT) C(4), D(4), and E(4) may partially mediate eosinophilic airway inflammation in patients with asthma. High- intensity exercise by patients with asthma can result in exercise- induced bronchoconstriction, partly due to leukotriene production, but it is still debated whether this causes airway inflammation. Ten subjects completed a randomized, controlled study to examine the effects of exercise-induced bronchoconstriction on airway inflammatory cells. Subjects completed exercise challenge and methacholine challenge in random order separated by 1 wk. Spirometry was measured for 2 h after challenges, and airway responsiveness was measured the day before and 24 h after each challenge. Blood and sputum samples were obtained before, and 2, 4, 7, and 24 h after each challenge for measurement of inflammatory cells. Nine of the subjects inhaled allergen at least 3 wk before or 1 wk after the study. Sputum samples were collected before, 7 h, and 24 h after challenge. The maximum percentage fall in FEV(1) was 21.3 +/- 1.5% after exercise, 29.9 +/- 1.5% after methacholine, and 28.9+/-2.7% after allergen. Exercise had no effect on airway responsiveness or inflammatory cells measured in blood or sputum, unlike allergen inhalation, which resulted in significant airway hyperresponsiveness and increases in sputum eosinophils (p < 0.05). This study demonstrates that exercise-induced bronchoconstriction does not cause eosinophilic airway inflammation in subjects with asthma who develop airway inflammation with the same degree of allergen-induced bronchoconstriction. We conclude that exercise-induced bronchoconstriction does not cause airway inflammation or airway hyperresponsiveness.
半胱氨酰白三烯（LT）C4、D4和E4可能部分介导哮喘患者的嗜酸性气道炎症。哮喘患者进行高强度运动可导致运动诱发的支气管收缩，部分原因是白三烯的产生，但运动是否会引发气道炎症仍存在争议。10名受试者完成了一项随机对照研究，以检验运动诱发的支气管收缩对气道炎症细胞的影响。受试者以随机顺序完成运动激发试验和乙酰甲胆碱激发试验，两次试验间隔1周。激发试验后2小时测量肺活量，每次激发试验前一天和激发后24小时测量气道反应性。在每次激发试验前以及激发后2、4、7和24小时采集血液和痰液样本，用于测量炎症细胞。9名受试者在研究前至少3周或研究后1周吸入了过敏原。在激发试验前、激发后7小时和24小时采集痰液样本。运动后FEV1的最大下降百分比为21.3±1.5%，乙酰甲胆碱激发试验后为29.9±1.5%，过敏原激发试验后为28.9±2.7%。与吸入过敏原不同，运动对血液或痰液中测量的气道反应性或炎症细胞没有影响，吸入过敏原会导致明显的气道高反应性和痰液嗜酸性粒细胞增加（p<0.05）。这项研究表明，在因过敏原诱发的支气管收缩程度相同而发生气道炎症的哮喘受试者中，运动诱发的支气管收缩不会引起嗜酸性气道炎症。我们得出结论，运动诱发的支气管收缩不会引起气道炎症或气道高反应性。
