Multiple exposures to swine barn air induce lung inflammation and airway hyper-responsiveness.
Multiple exposures to swine barn air induce lung inflammation and airway hyper-responsiveness.
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DOI：
10.1186/1465-9921-6-50
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发表时间：
2005-06-02
影响因子：
5.8
通讯作者：
Singh B
中科院分区：
文献类型：
--
作者：
Charavaryamath C;Janardhan KS;Townsend HG;Willson P;Singh B
养猪户反复暴露在谷仓空气中会患上呼吸系统疾病。然而，反复暴露在谷仓空气中的肺功能障碍的机制在很大程度上仍不清楚。因此，我们在一只大鼠模型中测试了一种假设，即多次间断暴露于谷仓空气会导致慢性肺部炎症和肺功能下降。将大鼠暴露在猪舍(每天8小时，持续1天、5天或20天)或环境空气中。暴露结束后，测定大鼠对乙酰胆碱(MCH)的气道高反应性(AHR)，并处死大鼠，收集支气管肺泡灌洗液(BALF)、血液和肺组织。对谷仓空气进行采样，以确定内毒素水平和微生物负荷。本研究中使用的谷仓空气中的内毒素浓度非常高(15361.75±7712.16 EU/m~3)。暴露于谷仓空气1天和5天的大鼠，与暴露20天和对照组相比，AHR增加。暴露组的肺部发炎，三个暴露组的中性粒细胞和嗜酸性粒细胞的聚集，以及暴露5天和20天组的呼吸道上皮杯状细胞的数量增加。暴露于谷仓空气1天或20天的大鼠BALF中的总白细胞数高于对照组和暴露1天和5天的大鼠(P<；0.05)，暴露20天的大鼠的气道上皮杯状细胞比对照组和暴露5天的大鼠多(P<0.05)。暴露20天的大鼠肺中的支气管相关淋巴组织(BALT)含有生发中心和有丝分裂细胞，表明处于激活状态。两组间的气道平滑肌细胞体积或中隔巨噬细胞募集无差异。我们的结论是，多次暴露于含有内毒素的猪舍空气可诱导AHR，含粘液的呼吸道上皮细胞增加，并导致肺部炎症。数据还表明，长期多次暴露也可能诱导暴露对象的AHR反应的适应性。
Swine farmers repeatedly exposed to the barn air suffer from respiratory diseases. However the mechanisms of lung dysfunction following repeated exposures to the barn air are still largely unknown. Therefore, we tested a hypothesis in a rat model that multiple interrupted exposures to the barn air will cause chronic lung inflammation and decline in lung function. Rats were exposed either to swine barn (8 hours/day for either one or five or 20 days) or ambient air. After the exposure periods, airway hyper-responsiveness (AHR) to methacholine (Mch) was measured and rats were euthanized to collect bronchoalveolar lavage fluid (BALF), blood and lung tissues. Barn air was sampled to determine endotoxin levels and microbial load. The air in the barn used in this study had a very high concentration of endotoxin (15361.75 ± 7712.16 EU/m3). Rats exposed to barn air for one and five days showed increase in AHR compared to the 20-day exposed and controls. Lungs from the exposed groups were inflamed as indicated by recruitment of neutrophils in all three exposed groups and eosinophils and an increase in numbers of airway epithelial goblet cells in 5- and 20-day exposure groups. Rats exposed to the barn air for one day or 20 days had more total leukocytes in the BALF and 20-day exposed rats had more airway epithelial goblet cells compared to the controls and those subjected to 1 and 5 exposures (P < 0.05). Bronchus-associated lymphoid tissue (BALT) in the lungs of rats exposed for 20 days contained germinal centers and mitotic cells suggesting activation. There were no differences in the airway smooth muscle cell volume or septal macrophage recruitment among the groups. We conclude that multiple exposures to endotoxin-containing swine barn air induce AHR, increase in mucus-containing airway epithelial cells and lung inflammation. The data also show that prolonged multiple exposures may also induce adaptation in AHR response in the exposed subjects.
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DOI：
10.1152/ajplung.00047.2003
发表时间：
2004-07-01
影响因子：
4.9
作者：
Kim, JH;Lee, SY;Yoo, SH
通讯作者：
Yoo, SH
DOI：
10.1152/ajplung.00001.2003
发表时间：
2003-09-01
影响因子：
4.9
作者：
Brass, DM;Savov, JD;Schwartz, DA
通讯作者：
Schwartz, DA
影响因子：
6
作者：
Ermert, L;Ermert, M;Seeger, W
通讯作者：
Seeger, W
影响因子：
15.9
作者：
DICOSMO, BF;GEBA, GP;FLAVELL, RA
通讯作者：
FLAVELL, RA
影响因子：
24.3
作者：
Cormier, Y;Duchaine, C;Dosman, J
通讯作者：
Dosman, J