Potassium transport by turtle colon: active secretion and active absorption.
Potassium transport by turtle colon: active secretion and active absorption.
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龟结肠转运钾：主动分泌、主动吸收。
DOI：
10.1152/ajpcell.1984.246.3.c315
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
Dawson,DC
中科院分区：
文献类型：
--
作者：
Halm,DR;Dawson,DC
测量跨上皮钾通量的跨壁电化学电位梯度的情况下，离体龟结肠可以积极吸收和积极分泌K+。在短路条件下，主动分泌流被抑制粘膜阿米洛利，而吸收流不受利尿剂。哇巴因和钡对分泌流的影响与一个简单的模型相一致，该模型涉及Na+-K+-ATP酶的基底外侧摄取，并且跨顶膜和基底外侧膜存在传导。主动吸收通量被粘膜哇巴因和血清钡阻断。相反的主动流动清楚地代表细胞K+运输，而细胞旁K+流的行为如预期的自由溶液分流。
Measurement of transepithelial potassium fluxes in the absence of transmural electrochemical potential gradients showed that the isolated turtle colon can actively absorb and actively secrete K+. Under short-circuit conditions the active secretory flow was inhibited by mucosal amiloride, whereas the absorptive flow was unaffected by the diuretic. The effects of ouabain and barium on secretory flow were consistent with a simple model involving basolateral uptake by an Na+-K+-ATPase and conductive exist across the apical and basolateral membranes. The active absorptive flux was blocked by mucosal ouabain and by serosal barium. The opposing active flows clearly represented cellular K+ transport, whereas paracellular K+ flows behaved as expected for a free-solution shunt.