Repeated hyperventilation causes peripheral airways inflammation, hyperreactivity, and impaired bronchodilation in dogs
Repeated hyperventilation causes peripheral airways inflammation, hyperreactivity, and impaired bronchodilation in dogs
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DOI：
10.1164/ajrccm.164.5.2003081
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发表时间：
2001-09-01
影响因子：
24.7
通讯作者：
Freed, AN
中科院分区：
文献类型：
--
作者：
Davis, MS;Freed, AN
冬季运动员哮喘的发病率增加，这表明反复使用冷空气过度换气可能会使个人容易患上呼吸道疾病。我们使用运动性呼吸亢进的犬模型来检测反复过度换气与凉爽、干燥的空气(即干燥空气挑战[DAC])对外周呼吸道阻力(RP)、反应性和炎症的影响。将特定的支气管暴露于单一DAC中，连续5天。每天测量雾化组胺、静脉注射组胺或低碳酸血症的Rp和Delta Rp。第5天取肺泡灌洗液(BALF)。Rp在首次DAC后24 h由0.70+/-0.08升至1.13+/-0.22 cm H2O/ml/S(n=25)，第3天升至1.49+/-0.24 cm H2O/ml/S，并持续升高，重复DAC可增加对低碳酸血症和静脉注射组胺的反应性。静脉注射沙丁胺醇未能有效地降低挑战气道(第一天基线的111%)的RP，与单纯气道(基线的54%)相同。反复DAC导致BALF中性粒细胞、嗜酸性粒细胞和硫多肽白三烯增加。我们的结论是，反复的DAC会导致外周气道炎症、阻塞、高反应性，并损害β-激动剂诱导的松弛。这表明，除了平滑肌张力增加外，其他机制可能有助于反复过度换气引起的支气管阻塞和高反应性的发展。
Winter athletes have an increased incidence of asthma, suggesting that repetitive hyperventilation with cold air may predispose individuals to airways disease. We used a canine model of exercise induced hyperpnea to examine the effects of repeated hyperventilation with cool, dry air (i.e., dry air challenge [DAC]) on peripheral airway resistance (Rp), reactivity, and inflammation. Specific bronchi were exposed to a single DAC on five consecutive days. Rp and Delta Rp to aerosolized histamine, intravenous histamine, or hypocapnia were measured daily. Bronchoalveolar lavage fluid (BALF) was obtained on the fifth day. Rp increased from 0.70 +/- 0.08 to 1.13 +/- 0.22 cm H2O/ml/s (n = 25) 24 h after the first DAC, rose to 1.49 +/- 0.24 cm H2O/ml/s by Day 3, and remained elevated throughout the remainder of the protocol, Repeated DAC increased reactivity to hypocapnia and intravenous histamine. Intravenous salbutamol failed to reduce Rp as effectively in challenged airways (111% of Day 1 baseline) as in naive airways (54% of baseline). Repeated DAC caused increased BALF neutrophils, eosinophils, and sulfidopeptide leukotrienes. We conclude that repeated DAC causes peripheral airways inflammation, obstruction, hyperreactivity, and impaired beta -agonist-induced relaxation. This suggests that other mechanisms in addition to increased smooth muscle tone may contribute to the development of repetitive hyperventilation-induced bronchial obstruction and hyperreactivity.