The mechanism of coupled transport of sodium and chloride in isolated urinary bladder of the trout.
The mechanism of coupled transport of sodium and chloride in isolated urinary bladder of the trout.
复制标题
鳟鱼离体膀胱中钠和氯耦合运输的机制。
DOI：
10.1113/jphysiol.1979.sp012926
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发表时间：
1979
期刊：
影响因子：
--
通讯作者：
B. Lahlou
中科院分区：
文献类型：
--
作者：
B. Fossat;B. Lahlou
1.跨上皮钠和氯通量进行了测量，在解剖鳟鱼膀胱安装在尤辛室。粘膜-浆膜通量似乎包含线性和饱和（Km = 8 mM）组分，作为离子管腔浓度的函数。Cl的总渗透率高于Na。从粘膜侧去除任一离子都会引起共离子净通量的消失，即使替代离子不是不可渗透的。这表明Na和Cl运输之间存在完全和特定的相互依赖性。大部分（30 - 50%）的氯离子交换归因于交换扩散过程。2.为了定位离子结合的位点，通过短期暴露于放射性同位素（2 min）来测量Na和Cl的顶端摄取。顶端通量与跨上皮通量相似，因此似乎是离子转移的限制因素。粘膜侧的离子置换表明，Na和Cl之间的耦合和Cl/Cl交换发生在这一步。
1. Transepithelial fluxes of Na and Cl were measured in dissected trout bladders mounted in Ussing chambers. The mucosa‐to‐serosa fluxes appeared to comprise a linear and a saturating (Km = 8 mM) component as a function of the luminal concentration of the ion. The over‐all permeability for Cl was higher than for Na. Removal of either ion from the mucosal side induced the disappearance of the net flux of the co‐ion even when the substituting ions were not impermeant. This indicated a complete and specific mutual dependence between the Na and Cl transports. A large part (30‐50%) of Cl exchanges was ascribed to an exchange‐diffusion process. 2. In order to localize the site of ion copuling, the apical uptakes of Na and Cl were measured by short‐term exposure (2 min) to radioisotopes. The apical fluxes were similar to the transepithelial fluxes and therefore appeared to be the limiting factor for ion transfer. Ionic replacements on the mucosal side showed that the coupling between Na and Cl and Cl/Cl exchange occurs at this step.