Regulation of ion transport across porcine distal bronchi.
Regulation of ion transport across porcine distal bronchi.
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猪远端支气管离子转运的调节。
DOI：
10.1152/ajplung.1996.270.2.l289
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Ballard,ST
中科院分区：
文献类型：
--
作者：
Inglis,SK;Corboz,MR;Taylor,AE;Ballard,ST
远端气道占人类气道总表面积的绝大多数，但人们对这些组织中的跨上皮离子转运知之甚少。通过测量刺激近端气道 Cl- 分泌的促分泌素的作用，研究了调节猪小支气管（外径 3.62 +/- 0.04 mm）中离子转运的途径。远端支气管的静息电位差 (PD)、短路电流 (ISC) 和电阻 (Rt) 分别为 3.4 +/- 0.1 mV（管腔阴性）、40.8 +/- 1.7 microA/cm2 和 92.1 +/- 5.0 omega.cm2。异丙肾上腺素 (10 µM)、乙酰胆碱 (ACh；10 µM) 或 ATP (100 µM) 诱导 PD 和 ISC 立即显着增加（P < 0.05）。 Ca2+ 离子载体 A23187 (1 µM) 诱导 PD 缓慢增加，同时 Rt 显着增加 2.4 倍，而 ISC 没有变化。在 10 µM 阿米洛利存在下，对异丙肾上腺素、ACh 和 ATP 的反应得以维持。用 10 µM 布美他尼进行预处理以阻断 Cl- 分泌，抑制对异丙肾上腺素和 ATP 的反应，但不抑制对 ACh 的反应。仅当 Cl- 和 HCO3- 分泌被阻断后，ACh 作用才会受到抑制。这些数据表明异丙肾上腺素、ACh 和 ATP 刺激阴离子分泌。异丙肾上腺素和 ATP 特异性刺激 Cl- 分泌，而 ACh 可以刺激 Cl- 和 HCO3- 分泌。 A23187 对活性跨上皮离子转运没有影响，但增加完整远端支气管上皮的屏障抵抗力。
Distal airways comprise the vast majority of total human airway surface area, yet little is known about transepithelial ion transport in these tissues. Pathways that regulate ion transport in porcine small bronchi (3.62 +/- 0.04 mm outer diameter) were studied by measuring the effects of secretogogues that stimulate Cl- secretion in proximal airways. Resting potential difference (PD), shortcircuit current (ISC), and resistance (Rt) across the distal bronchi were 3.4 +/- 0.1 mV (lumen negative), 40.8 +/- 1.7 microA/cm2, and 92.1 +/- 5.0 omega.cm2, respectively. Isoproterenol (10 microM), acetylcholine (ACh; 10 microM), or ATP (100 microM) induced immediate significant (P < 0.05) increases in PD and ISC. The Ca2+ ionophore A23187 (1 microM) induced a slow increase in PD that was accompanied by a significant 2.4-fold increase in Rt and no change in ISC. The responses to isoproterenol, ACh, and ATP were maintained in the presence of 10 microM amiloride. Pretreatment with 10 microM bumetanide to block Cl- secretion inhibited responses to isoproterenol and ATP but not to ACh. The ACh effect was inhibited only after both Cl- and HCO3- secretion were blocked. These data suggest that isoproterenol, ACh, and ATP stimulate anion secretion. Isoproterenol and ATP specifically stimulate Cl- secretion, whereas ACh can stimulate both Cl- and HCO3- secretion. A23187 has no effect on active transepithelial ion transport but increases barrier resistance in intact distal bronchial epithelium.