Noninvasive in vivo fluorescence measurement of airway-surface liquid depth, salt concentration, and pH
Noninvasive in vivo fluorescence measurement of airway-surface liquid depth, salt concentration, and pH
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DOI：
10.1172/jci11154
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发表时间：
2001-02-01
影响因子：
15.9
通讯作者：
Verkman, AS
中科院分区：
文献类型：
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作者：
Jayaraman, S;Song, YL;Verkman, AS
大气道表面薄层液体（气道表面液体（ASL））中盐的浓度被认为在气道生理学和囊性纤维化的病理生理学中至关重要。侵入式采样方法已产生从 40 到 180 mM 的各种 ASL [NaCl]。我们开发了新型荧光探针和显微镜方法，可以在细胞培养模型和体内气管中定量测量 ASL 厚度、盐浓度和 pH 值。通过快速 z 扫描共聚焦显微镜，在空气-液体界面的多孔支撑物上生长的牛气管上皮细胞的分化良好的培养物中，ASL 厚度为 21 +/- 4 微米。通过使用钠、氯和 pH 敏感荧光指示剂的比率成像荧光显微镜，ASL [Na+] 为 97 +/- 5 mM，[Cl-] In 为 118 +/- 3 mM，pH 为 6.94 +/- 0.03。在气管中形成透明窗口的麻醉小鼠中，ASL厚度为45+/-5μm，[Na+]为115+/-4mM，[Cl-]为140+/-5mM，pH为6.95+/-0.05。在囊性纤维化 (CFTR-null) 小鼠中也发现了类似的 ASL 张力和 pH 值。在新鲜收获的人支气管中，ASL厚度为55+/-5μm，[Na+]为103+/-3mM，[Cl-]为92+/-4mM，pH为6.78+/-0.2。这些结果通过非侵入性方法确定了 ASL 的关键特性，并提供了直接证据，证明 ASL 近似等渗，并且在囊性纤维化中并不更咸。
The concentration of salt in the thin layer of fluid at the surface of large airways, the airway-surface liquid (ASL), is believed to he of central importance in airway physiology and in the pathophysiology of cystic fibrosis. Invasive sampling methods have yielded a wide range of ASL [NaCl] from 40 to 180 mM. We have developed novel fluorescent probes and microscopy methods to measure ASL thickness, salt concentration, and pH quantitatively in cell-culture models and in the trachea in vivo. By rapid z-scanning confocal microscopy, ASL thickness was 21 +/- 4 mum in well-differentiated cultures of bovine tracheal epithelial cells grown on porous supports at an air-liquid interface. By ratio imaging fluorescence microscopy using sodium, chloride, and pH-sensitive fluorescent indicators, ASL [Na+] was 97 +/- 5 mM, [Cl-] In as 118 +/- 3 mM, and pH was 6.94 +/- 0.03. In anesthetized mice in which a transparent window was created in the trachea, ASL thickness was 45 +/- 5 mum, [Na+] was 115 +/- 4 mM, [Cl-] was 140 +/- 5 mM, and pH was 6.95 +/- 0.05. Similar ASL tonicity and pH were found in cystic fibrosis (CFTR-null) mice. In freshly harvested human bronchi, ASL thickness was 55 +/- 5 mum, [Na+] was 103 +/- 3 mM, [Cl-] was 92 +/- 4 mM, and pH was 6.78 +/- 0.2. These results establish by a noninvasive approach the key properties of the ASL and provide direct evidence that the ASL is approximately isotonic and not saltier in cystic fibrosis.