Reactive absorption of nitrogen dioxide by pulmonary epithelial lining fluid.
Reactive absorption of nitrogen dioxide by pulmonary epithelial lining fluid.
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肺上皮内层液对二氧化氮的反应性吸收。
DOI：
10.1152/jappl.1990.69.2.523
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Bidani,A
中科院分区：
文献类型：
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作者：
Postlethwait,EM;Langford,SD;Bidani,A
在先前对离体大鼠肺进行的研究（J. Appl. Physiol. 68: 594-603, 1990）中，我们认为吸入 NO2 的肺气隙吸收率部分受到化学反应而非物理溶解度的限制。由于主要吸收相互作用的初始位点涉及上皮衬里液 (ELF)，因此我们研究了 ELF-NO2 相互作用是否可以解释肺 NO2 反应性吸收。通过支气管肺泡灌洗 (BAL) 获得的大鼠 ELF 与模型化学系统（还原型谷胱甘肽，GSH）进行了比较。体外暴露（NO2-空气）使用恒定气流和平面气液界面。 1) 溶剂 pH 值显着改变了 GSH 对 NO2 的吸收，但 BAL 的吸收程度较小。 2) 摄取显示出[GSH]依赖性饱和度。通过对多个肺进行连续灌洗（灌洗重复使用）增强了 BAL 中的 [ELF]。吸收与[ELF]成正比，但在这些暴露条件下并未饱和。 3) 摄取率表现出[NO2]依赖性。然而，相对于 [NO2] 的增加，BAL 和 1 mM GSH 的摄取分数下降，但 10 mM GSH 则没有。 4) 改变对流气流产生了吸收量的非线性增量（10 mM GSH）和吸收分数的大幅减少。 5) BAL 和 1 mM GSH 的阿伦尼乌斯图 [ln(r) vs. 1/T，其中 r 是反应速率，T 是绝对温度（度 K）] 分别产生 4,952 和 4,149 kcal.g-1.mol-1 的活化能，每 10 摄氏度 (Q10) 吸收 NO2 速率的变化程度分别为 1.32 和 1.25。这些结果表明，大鼠 ELF 吸收 NO2 的速率，就像完整的肺一样，部分受到化学反应的限制。（摘要截断为 250 字）
In a previous study (J. Appl. Physiol. 68: 594-603, 1990) in isolated rat lungs, we suggested that the rate of pulmonary air space absorption of inhaled NO2 is limited, in part, by chemical reaction(s) rather than by physical solubility. Because the initial site of primary absorption interactions involves the epithelial lining fluid (ELF), we investigated whether ELF-NO2 interactions could account for pulmonary NO2 reactive absorption. Rat ELF, obtained by bronchoalveolar lavage (BAL), was compared with a model chemical system (reduced glutathione, GSH). In vitro exposures (NO2-air) used constant gas flow and planar gas-liquid interfaces. 1) Solvent pH notably altered NO2 uptake by GSH but to a lesser extent by BAL. 2) Uptake displayed [GSH]-dependent saturation. [ELF] in BAL was augmented by sequential lavage (lavagate reuse) of multiple lungs. Uptake was proportional to [ELF] but did not saturate under these exposure conditions. 3) The uptake rate exhibited [NO2] dependence. However, relative to increasing [NO2], fractional uptakes decreased for BAL and 1 mM GSH but not for 10 mM GSH. 4) Altered convective gas flow produced nonlinear increments in uptake (10 mM GSH) and substantial decrements in fractional uptake. 5) Arrhenius plots [ln(r) vs. 1/T, where r is reaction rate and T is absolute temperature (degree K)] for BAL and 1 mM GSH yielded respective activation energies of 4,952 and 4,149 kcal.g-1.mol-1 and degree of change in the rate of NO2 uptake per 10 degrees C (Q10) of 1.32 and 1.25. These results imply that the rate of NO2 uptake into rat ELF, like intact lung, is limited, in part, by chemical reaction(s).(ABSTRACT TRUNCATED AT 250 WORDS)