CONTROL OF PH OF AIRWAY SURFACE LIQUID OF THE FERRET TRACHEA INVITRO
CONTROL OF PH OF AIRWAY SURFACE LIQUID OF THE FERRET TRACHEA INVITRO
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DOI：
10.1152/jappl.1990.68.1.135
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发表时间：
1990-01-01
影响因子：
3.3
通讯作者：
WIDDICOMBE, JG
中科院分区：
文献类型：
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作者：
KYLE, H;WARD, JPT;WIDDICOMBE, JG
我们测量了雪貂气管分泌的气道表面液体（ASL）的pH值在体外通过使用导管尖端的pH电极植入在收集套管接近气道上皮。在器官浴中用间甲胆碱（0.02 mmol/l）促进粘液分泌。ASL的pH为6.85 ±。0.03（SE），而浴值为7.39 ±。0.01，当浴用5.65%CO2鼓泡时。将浴CO2从0改变到20.93%CO2，浴pH从8.06改变到6.96，但ASL pH仅从6.92改变到6.85。ASL pH值的这种稳态不是ASL缓冲能力的结果，因为分泌型ASL的异位缓冲曲线与Krebs-Henseleit溶液相似。通过气管吹入气体来改变腔内CO2含量，可以改变ASL pH值，其值与离体pH值相似。然而，当外部器官浴CO2改变时，管腔CO2的变化比例要小得多。测量CO2穿过气管壁的扩散速率表明，这不是结果的限制因素。同样，测量气管管腔中的代谢率CO2产生表明，这不会显著影响结果。我们的结论是，ASL的pH值显着的酸性侧的组织液和血浆的pH值，它是保持相对恒定，尽管外部pH值的变化很大。
We measured the pH of airway surface liquid (ASL) secreted by the ferret trachea in vitro by using a catheter-tipped pH electrode implanted in a collecting cannula close to the airway epithelium. Mucus secretion was promoted by metacholine (0.02 mmol/l) in the organ bath. The pH of the ASL was 6.85 .+-. 0.03 (SE) compared with a bath value of 7.39 .+-. 0.01, when the bath was bubbled with 5.65% CO2. Changing the bath CO2 from 0 to 20.93% CO2 altered the bath pH from 8.06 to 6.96, but the ASL pH only varied from 6.92 to 6.85. This homeostasis of ASL pH was not the result of the buffering powers of the ASL, because ex situ buffer curves for secreted ASL were similar to those for Krebs-Henseleit solution. Changing the luminal CO2 content by blowing gases through the trachea changed ASL pH by values similar to that ex situ. However, when external organ bath CO2 was changed, the luminal CO2 changes were proportionately far smaller. Measurement of rates of diffusion of CO2 across the tracheal wall indicated that this was not a limiting factor in the results. Similarly, measurement of metabolic rate CO2 production in the tracheal luman indicated that this did not significantly affect the results. We conclude that the pH of ASL is significantly on the acid side of the pH of interstitial fluid and plasma and that it is maintained relatively constant despite large changes in external pH.