Potassium conductances in tracheal epithelium activated by secretion and cell swelling.
Potassium conductances in tracheal epithelium activated by secretion and cell swelling.
复制标题
气管上皮中的钾电导由分泌和细胞肿胀激活。
DOI：
10.1152/ajpcell.1990.258.4.c630
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Frizzell,RA
中科院分区：
文献类型：
--
作者：
Butt,AG;Clapp,WL;Frizzell,RA
增加基底外侧膜钾电导伴随着刺激氯分泌穿过犬气管。为了评估钾的电导特性，我们用两性霉素B渗透根尖膜，并监测钾通过基底外侧膜引起的电流和电导。在基础非刺激条件下，阻滞剂可以区分两种K电导。一种只受钡的抑制；另一个对奎尼丁和利多卡因也敏感。基底电导通路对K和Rb的渗透率相似（PK/PRb约为1.5）。分泌激动剂肾上腺素选择性地增加奎尼丁不敏感电导，暗示其参与Cl分泌反应。细胞肿胀诱导了第三种电导，其对Rb的渗透性较低（PK/PRb约为10），对奎尼丁敏感。在未用两性霉素治疗的组织中，奎尼丁和Rb-for-K替代均未抑制上皮细胞Cl的分泌。因此，这两种奎尼丁敏感的钾电导（基底或肿胀诱导）都不会导致Cl分泌过程中基底外侧钾电导的增加。细胞收缩抑制了这三种传导和分泌，表明细胞的初始优先级是体积调节。
Increased basolateral membrane K conductance accompanies stimulation of Cl secretion across canine trachea. To assess the K conductance properties, we permeabilized the apical membranes with amphotericin B and monitored the current and conductance caused by K flow across the basolateral membranes. Under basal unstimulated conditions, two K conductances could be distinguished by blockers. One was inhibited only by barium; the other was sensitive also to quinidine and lidocaine. The permeabilities of the basal conductance pathways to K and Rb were similar (PK/PRb approximately equal to 1.5). The secretory agonist, epinephrine, selectively increased the quinidine-insensitive conductance, implicating it in the Cl secretory response. Cell swelling induced a third conductance with a low permeability to Rb (PK/PRb approximately equal to 10) that was quinidine sensitive. In tissues not treated with amphotericin, neither quinidine nor Rb-for-K replacement inhibited transepithelial Cl secretion. Thus neither of the quinidine-sensitive K conductances (basal or swelling induced) contribute to the increase in basolateral K conductance during Cl secretion. Cell shrinkage inhibited all three conductances and secretion, suggesting that the initial priority of the cell is volume regulation.