Pauwels R A, Kips J C, Peleman R A, Van Der Straeten M E
Department of Respiratory Diseases, University Hospital, Ghent, Belgium.
Am Rev Respir Dis. 1990 Mar;141(3):540-5. doi: 10.1164/ajrccm/141.3.540.
Studies in humans suggests that airway inflammation may modulate nonspecific airway responsiveness. We studied in a rat model the effect of the inhalation of endotoxin on the cellular composition of the bronchoalveolar lavage (BAL) fluid and airway responsiveness. The exposure to an aerosol of endotoxin caused a rapid influx of neutrophils in the airways. The neutrophils persisted up to 24 h after exposure. Elastase activity in lavage fluid became detectable 30 min after the endotoxin exposure and peaked 9 h later. The exposure to the endotoxin aerosol was followed 1 to 2 h later by a significant increase in the airway responsiveness to 5-hydroxytryptamine (5HT). However, the increase in responsiveness disappeared, and 9 to 12 h following the end of the exposure a significant decrease in airway 5HT responsiveness was observed at the moment that more than 80% of the cells contained in the BAL fluid were neutrophils. The effect of endotoxin on airway responsiveness and inflammation was dose dependent. We also compared in three different inbred rat strains the effect of endotoxin inhalation. The aerosol exposure induced in all three strains a comparable neutrophil influx in the airways, but only two of the three strains became hyperresponsive to 5HT. We conclude that the inhalation of endotoxin causes a neutrophilic airway inflammation in rats. The relationship between this airway inflammation and airway responsiveness is dependent on the time following the exposure and the animal strain used.
对人类的研究表明，气道炎症可能会调节非特异性气道反应性。我们在大鼠模型中研究了吸入内毒素对支气管肺泡灌洗（BAL）液细胞组成和气道反应性的影响。暴露于内毒素气雾剂会导致气道中嗜中性粒细胞迅速流入。暴露后嗜中性粒细胞可持续长达24小时。内毒素暴露30分钟后，灌洗液中的弹性蛋白酶活性可检测到，并在9小时后达到峰值。暴露于内毒素气雾剂1至2小时后，气道对5-羟色胺（5HT）的反应性显著增加。然而，反应性的增加消失了，在暴露结束后9至12小时，当BAL液中超过80%的细胞为嗜中性粒细胞时，观察到气道5HT反应性显著降低。内毒素对气道反应性和炎症的影响呈剂量依赖性。我们还比较了三种不同近交系大鼠吸入内毒素的效果。气雾剂暴露在所有三个品系中均引起气道中类似的嗜中性粒细胞流入，但三个品系中只有两个对5HT变得高反应性。我们得出结论，吸入内毒素会导致大鼠嗜中性粒细胞性气道炎症。这种气道炎症与气道反应性之间的关系取决于暴露后的时间和所用的动物品系。
