Bioelectric properties and ion transport of excised rabbit trachea.
Bioelectric properties and ion transport of excised rabbit trachea.
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离体兔气管的生物电特性和离子传输。
DOI：
10.1152/jappl.1983.55.6.1884
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
R. Boucher
中科院分区：
文献类型：
--
作者：
F. Jarnigan;J. Davis;P. Bromberg;J. Gatzy;R. Boucher
体外测定了兔气管（无粘膜下腺的气道上皮）的生物电特性和22Na+和36Cl-同位素流动。122个切除气管的平均上皮电位差（PD）为12 mV（流明负），电导(G)为8.5 mS X cm-2，短路电流（Isc）为90 microA X cm-2。G在3 h以上保持稳定，但Isc和PD下降缓慢（10%/h）。G与PD呈负相关，Isc与G不相关。Na+在两种开路条件下均吸附（1.7 μ eq）。cm-2 X h-1)和短路（2.2 mueq X cm-2 X h-1）条件。净Na+输运占短路气管Isc的70%。吸收方向的净Cl-流量近似于开路条件下的Na+流量（1.6 μ eq X cm-2 X h-1）。在短路条件下，分泌方向的Cl-净流量（0.4 μ eq X cm-2 X h-1）不显著。两种单向Cl-通量均与G相关；[14C]-甘露醇渗透性和Na+流动与g的相关性较弱或不相关。我们没有发现净HCO-3或质子传输的证据。乙酰胆碱（10(-4)M）、苯肾上腺素（10(-5)M）或异丙肾上腺素（10(-5)M）没有引起生物电特性或离子流动的变化。我们得出结论，兔气管主要是一个吸收Na+的上皮。甘露醇渗透性与G之间没有相关性，这表明大部分Cl-电导是跨细胞的。然而，兔气管对胆碱能和肾上腺素能药物的不敏感与腺体的缺失是一致的，而对肾上腺素能激动剂的缺乏反应表明（与犬气管相比）气道表面上皮细胞功能的物种差异。
Bioelectric properties and 22Na+ and 36Cl- isotopic flows across rabbit trachea, an airway epithelium without submucosal glands, were measured in vitro. One hundred twenty-two excised tracheas exhibited a mean transepithelial electric potential difference (PD) of 12 mV (lumen negative), a conductance (G) of 8.5 mS X cm-2, and a short-circuit current (Isc) of 90 microA X cm-2. G remained stable for more than 3 h, but Isc and PD fell slowly (10%/h). G was inversely correlated with PD, but Isc and G were not correlated. Na+ was absorbed under both open-circuit (1.7 mueq. cm-2 X h-1) and short-circuit (2.2 mueq X cm-2 X h-1) conditions. Net Na+ transport accounted for 70% of Isc of the short-circuited trachea. Net Cl- flow in the absorptive direction approximated that of Na+ under open-circuit conditions (1.6 mueq X cm-2 X h-1). Under short-circuit conditions the small net flow of Cl- in the direction of secretion (0.4 mueq X cm-2 X h-1) was not significant. Both unidirectional Cl- fluxes were correlated with G; [14C]-mannitol permeability and Na+ flows were weakly or not correlated with G. We found no evidence of net HCO-3 or proton transport. Acetylcholine (10(-4) M), phenylephrine (10(-5) M), or isoproterenol (10(-5) M) induced no change in bioelectric properties or ion flows. We conclude that the rabbit trachea is primarily a Na+ absorbing epithelium. The absence of a correlation between mannitol permeability and G suggests that much of the Cl- conductance is transcellular. Whereas insensitivity of rabbit trachea to cholinergic and alpha-adrenergic agents is compatible with the absence of glands, the lack of response to beta-adrenergic agonists denotes a species difference (compared with canine trachea) in airway-surface epithelial cell function.