Evidence of Na-K-Cl cotransport in airway smooth muscle.
Evidence of Na-K-Cl cotransport in airway smooth muscle.
复制标题
Na-K-Cl 在气道平滑肌中协同转运的证据。
DOI：
10.1152/ajplung.1995.268.4.l551
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Douglas,JS
中科院分区：
文献类型：
--
作者：
Rhoden,KJ;Douglas,JS
通过测量豚鼠气管中的~（86）Rb+（作为K+的标记）和~（36）Cl-通量，研究了气道平滑肌中Na-K-Cl协同转运蛋白的存在。K+摄取由1）布美他尼和呋塞米敏感组分，2）哇巴因敏感组分，和3）布美他尼和哇巴因不敏感组分组成。布美他尼和呋塞米抑制K+摄取，IC 50分别为0.18和5.6 μ M。布美他尼敏感的K+摄取减少细胞外Na+和Cl-的等渗置换与胆碱和I-，分别。布美他尼导致Cl-摄取减少，布美他尼敏感的K+与Cl-摄取的比率约为1：1.75。布美他尼导致86 Rb+流出减少，表明Na-K-Cl协同转运蛋白介导气道平滑肌中K+内流和外流。哇巴因引起的布美他尼敏感的86 Rb+流出的豚鼠气管，这是防止暴露于低Na+介质，这表明钠钾泵抑制刺激外向钠钾氯共转运的结果增加细胞内Na+含量。
The presence of the Na-K-Cl cotransporter in airway smooth muscle was investigated by measuring 86Rb+ (as a marker for K+) and 36Cl- fluxes in the guinea pig trachealis. K+ uptake consisted of 1) a bumetanide- and furosemide-sensitive component, 2) a ouabain-sensitive component, and 3) a bumetanide- and ouabain-insensitive component. Bumetanide and furosemide inhibited K+ uptake with IC50s of 0.18 and 5.6 microM, respectively. Bumetanide-sensitive K+ uptake was reduced by the isosmotic replacement of extracellular Na+ and Cl- with choline and I-, respectively. Bumetanide caused a reduction in Cl- uptake, and the ratio of bumetanide-sensitive K+ to Cl-uptake was approximately 1:1.75. Bumetanide caused a decrease in 86Rb+ efflux, suggesting that the Na-K-Cl cotransporter mediates both K+ influx and efflux in airway smooth muscle. Ouabain caused an increase in bumetanide-sensitive 86Rb+ efflux from the guinea pig trachealis, which was prevented by exposure to a low-Na+ medium, suggesting that Na-K pump inhibition stimulates outward Na-K-Cl cotransport as a result of an increase in intracellular Na+ content.