Tessier G J, Lester G D, Langham M R, Cassin S
Department of Physiology, College of Medicine, University of Florida, Gainesville 32610, USA.
Am J Physiol. 1996 Jun;270(6 Pt 1):L1008-16. doi: 10.1152/ajplung.1996.270.6.L1008.
Alveolar type II cells were isolated from late-term fetal sheep to investigate ion transport across fetal distal lung epithelium. In Ussing chambers, basal transepithelial potential difference (PD; reference apical side), equivalent short-circuit current (Ieq), and resistance were -0.10 +/- 0.05 mV, 0.10 +/- 0.08 microA/cm2, and 821.5 +/- 38.8 omega .cm2, respectively. Epinephrine (100 nM) increased PD from -0.13 +/- 0.19 to -1.37 +/- 0.20 mV and Ieq from 0.18 +/- 0.26 to 1.47 +/- 0.28 microA/cm2. Propranolol (100 nM) inhibited responses to epinephrine. Forskolin (10 microM) increased PD to -0.81 +/- 0.08 mV and Ieq to 1.02 +/- 0.12 microA/cm2. Mucosal amiloride (200 microM) and serosal bumetanide (10 microM) decreased the forskolin-stimulated PD by 23.42 +/- 4.73 and 25.57 +/- 3.9%, respectively. We conclude that in fetal sheep distal lung epithelium amiloride-inhibitable sodium absorption and bumetanide-sensitive chloride secretion are stimulated by forskolin and that epinephrine effects on ion transport are mediated by beta-adrenergic receptors.
从晚期胎羊中分离出II型肺泡细胞，以研究离子跨胎儿远端肺上皮的转运。在尤斯灌流小室中，基础跨上皮电位差（PD；参考顶端侧）、等效短路电流（Ieq）和电阻分别为-0.10±0.05 mV、0.10±0.08 μA/cm²和821.5±38.8 Ω·cm²。肾上腺素（100 nM）使PD从-0.13±0.19 mV增加到-1.37±0.20 mV，使Ieq从0.18±0.26 μA/cm²增加到1.47±0.28 μA/cm²。普萘洛尔（100 nM）抑制对肾上腺素的反应。福斯高林（10 μM）使PD增加到-0.81±0.08 mV，使Ieq增加到1.02±0.12 μA/cm²。黏膜阿米洛利（200 μM）和浆膜布美他尼（10 μM）分别使福斯高林刺激的PD降低23.42±4.73%和25.57±3.9%。我们得出结论，在胎羊远端肺上皮中，福斯高林刺激阿米洛利可抑制的钠吸收和布美他尼敏感的氯分泌，并且肾上腺素对离子转运的作用由β-肾上腺素能受体介导。
