Sodium and chloride transport in zebrafish soft water and hard water acclimated (Danio rerio)
Sodium and chloride transport in zebrafish soft water and hard water acclimated (Danio rerio)
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DOI：
10.1016/j.bbamem.2003.08.016
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发表时间：
2003-12-30
影响因子：
3.4
通讯作者：
Grosell, M
中科院分区：
文献类型：
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作者：
Boisen, AMZ;Amstrup, J;Grosell, M
虽然斑马鱼通常用于发育生物学和毒理学研究，但人们对其渗透调节生理学知之甚少。目前对 Na+ 和 Cl- 转运的研究表明，斑马鱼能够耐受极低的环境离子浓度，并且这至少部分是通过大大增强的两种离子的表观吸收能力和亲和力来实现的。即使在仅含有 35 μM NaCl 的去离子水（即软水）中，斑马鱼也能维持与大多数其他淡水硬骨鱼相似的血浆和全身电解质浓度。我们记录了软水环境下鱼主动吸收 Cl- 的极低转运亲和常数 (K-m)，为 8 +/- 1 muM，而其他转运动力学参数与其他淡水生物的报告一致。虽然软水中 Na+ 和 Cl- 的吸收显然取决于顶端质子泵活性，但这种蛋白质的丰度变化和可能的定位似乎对软水驯化没有贡献。无论水的类型如何，活性 Cl- 吸收都强烈依赖于鳃碳酸酐酶 (CA) 活性，而 Na+ 转运对 CA 抑制剂的反应则变化更大。根据适应介质的不同，Na + 吸收对阿米洛利的不同反应表明，适应软水和硬水的斑马鱼采用不同的 Na + 转运机制。 (C) 2003 Elsevier B.V. 保留所有权利。
While the zebrafish is commonly used for studies of developmental biology and toxicology, very little is known about their osmoregulatory physiology. The present investigation of Na+ and Cl- transport revealed that the zebrafish is able to tolerate extremely low ambient ion concentrations and that this is achieved at least in part by a greatly enhanced apparent uptake capacity and affinity for both ions. Zebrafish maintain plasma and whole body electrolyte concentrations similar to most other freshwater teleosts even in deionized water containing only 35 muM NaCl, i.e soft water. We recorded an extremely low transport affinity constant (K-m) of 8 +/- 1 muM for the active uptake of Cl- in soft water acclimated fish, while other transport kinetic parameters were in agreement with reports for other freshwater organisms. While both Na+ and Cl- uptake in soft water clearly depends on apical proton pump activity, changes in abundance and possibly localization of this protein did not appear to contribute to soft water acclimation. Active Cl- uptake was strongly dependent on branchial carbonic anhydrase (CA) activity regardless of water type, while the response of Na+ transport to a CA inhibitor was more variable. Differential response of Na+ uptake to amiloride depending on acclimation medium suggests that different Na+ transport mechanisms are employed by zebrafish acclimated to soft and hard water. (C) 2003 Elsevier B.V. All rights reserved.