Excretion of cesium through potassuim transport pathway in the gills of a marine teleost
Excretion of cesium through potassuim transport pathway in the gills of a marine teleost
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海洋硬骨鱼鳃中通过钾转运途径排泄铯
DOI：
10.1007/978-4-431-54328-2_11
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Watanabe S.
中科院分区：
文献类型：
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作者：
Kaneko T;Furukawa F;Watanabe S.
我们使用了一种新开发的技术，不溶化和可视化从鳃中排泄的K+，以证明鳃富含线粒体（MR）细胞负责海水适应的莫桑比克罗非鱼的K+排泄。为了更好地了解K+从鳃中排泄的分子机制，我们鉴定了一些可能参与K+运输的候选分子的cDNA序列。在这些候选分子中，只有肾外髓K+通道（ROMK）在高外部K+浓度下表现出显著上调的mRNA水平。我们发现在MR细胞的顶端开口中表达的ROMK是负责K+排泄的主要分子途径。利用不溶化技术，我们进一步证明了Cs+和Rb+（已知是K+的生化类似物）通过海水罗非鱼鳃中的K+运输途径排泄。补充K+诱导鳃MR细胞中ROMK的激活可以更快地消除不必要的K+生化类似物，可能是水产养殖中抗放射性的有效对策。
We used a newly developed technique that insolubilizes and visualizes K+ excreted from the gills to demonstrate that gill mitochondria-rich (MR) cells are responsible for K+ excretion in seawater-acclimated Mozambique tilapia. To achieve a better understanding of the molecular mechanism of K+ excretion from the gills, we identified the cDNA sequences of some candidate molecules that may be involved in K+ transport. Of these candidate molecules, only a renal outer medullary K+ channel (ROMK) exhibited markedly upregulated mRNA levels in response to a high external K+ concentration. We found that ROMK expressed in the apical opening of MR cells was the main molecular pathway responsible for K+ excretion. Using the insolubilization technique, we further demonstrated the excretion of Cs+ and Rb+, which are known to be biochemical analogs of K+, through the K+ transport pathway in the gills of seawater tilapia. The activation of ROMK in the gill MR cells induced by K+ supplementation could eliminate unnecessary biochemical analogs of K+ more rapidly, possibly serving as an effective countermeasure against radiocesium in aquaculture.