Devalia J L, Sapsford R J, Cundell D R, Rusznak C, Campbell A M, Davies R J
Dept of Respiratory Medicine, St Bartholomew's Hospital, London, UK.
Eur Respir J. 1993 Oct;6(9):1308-16.
Nitrogen dioxide (NO2), is a major air pollutant, that causes bronchoconstriction and bronchial hyperreactivity, and may also lead to damage and inflammation of the airway epithelium. We have cultured human bronchial epithelial cells and investigated the effect of exposure to NO2, for 20 min on epithelial cell membrane integrity and function in vitro. Epithelial cell membrane damage and permeability were assessed by release of 51Cr from prelabelled cells, and movement of 14C-labelled bovine serum albumin (BSA) across the bronchial epithelial cell monolayers. Ciliary beat frequency (CBF) of the cells was monitored by the analogue contrast enhancement technique, and arachidonic acid (AA) metabolism was investigated by analysis of radiolabelled AA metabolites generated from cultures prelabelled by incubation with [3H]-arachidonic acid. Exposure to 400 and 800 parts per billion (ppb) NO2 significantly increased the release of 51Cr from 0.9 +/- 0.4%, in control cultures exposed to 5% CO2 in air, to 9.7 +/- 3.2% and 13.9 +/- 3.5%, respectively. Similarly, NO2 also significantly increased the movement of 14C-BSA across the epithelial monolayers from 1.3 +/- 0.2%, in control cultures, to 2.7 +/- 0.2%, 3.8 +/- 0.4% and 5.1 +/- 0.5%, respectively, in cultures exposed to 100, 400 and 800 ppb NO2. Although NO2 attenuated the CBF of the cells at all concentrations investigated, this was significant only at the concentration of 2,000 ppb NO2.(ABSTRACT TRUNCATED AT 250 WORDS)
二氧化氮（NO₂）是一种主要的空气污染物，可导致支气管收缩和支气管高反应性，还可能导致气道上皮损伤和炎症。我们培养了人支气管上皮细胞，并研究了体外暴露于NO₂ 20分钟对上皮细胞膜完整性和功能的影响。通过预标记细胞释放⁵¹Cr以及¹⁴C标记的牛血清白蛋白（BSA）穿过支气管上皮细胞单层的移动来评估上皮细胞膜损伤和通透性。通过模拟对比增强技术监测细胞的纤毛摆动频率（CBF），并通过分析与[³H] - 花生四烯酸孵育预标记的培养物中产生的放射性标记花生四烯酸代谢物来研究花生四烯酸（AA）代谢。暴露于400和800十亿分率（ppb）的NO₂显著增加了⁵¹Cr的释放，在暴露于空气中5% CO₂的对照培养物中，释放率从0.9±0.4%分别增加到9.7±3.2%和13.9±3.5%。同样，NO₂也显著增加了¹⁴C - BSA穿过上皮单层的移动，在对照培养物中为1.3±0.2%，在暴露于100、400和800 ppb NO₂的培养物中分别为2.7±0.2%、3.8±0.4%和5.1±0.5%。尽管在所有研究浓度下NO₂都减弱了细胞的CBF，但仅在2000 ppb NO₂浓度下才具有显著性。（摘要截断于250字）
