Strategies for maintaining Na+ balance in zebrafish (Danio rerio) during prolonged exposure to acidic water
Strategies for maintaining Na+ balance in zebrafish (Danio rerio) during prolonged exposure to acidic water
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DOI：
10.1016/j.cbpa.2011.05.001
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发表时间：
2011-09-01
影响因子：
2.3
通讯作者：
Perry, Steve F.
中科院分区：
文献类型：
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作者：
Kumai, Yusuke;Bahubeshi, Amin;Perry, Steve F.
本研究的目的是表征斑马鱼 (Danio rerio) 在暴露于酸性水 (pH 3.8-4.0) 期间调节全身 Na+ 水平的能力。暴露于酸性水会显着影响 14 种封闭蛋白和两种封闭蛋白亚型的 mRNA 水平，这些紧密连接蛋白被认为参与调节细胞旁流出。尽管有这些变化，Na + 流出以及聚乙二醇 (PEG)（细胞旁途径标志物）的摄取在暴露于酸的 2 周期间持续升高，尽管在 12 小时和 72 小时之间有短暂恢复。将鱼预先暴露于酸性水中两周未能减弱与急性暴露于低 [Ca2+] 的酸性水中相关的 Na+ 流出量的增加。然而，在暴露于酸性水后恢复到近中性pH值的过程中，Na+流出率在5小时内恢复到正常水平。接触酸性水 4 至 7 天内，Na+ 吸收率显着升高；这种增加与最大 Na+ 吸收能力 (J(MAX)Na(+)) 和亲和常数 (K-M) 的显着增加有关。这些结果表明，在酸性水中，斑马鱼主要通过调节Na+吸收而不是Na+流出来维持全身Na+平衡。 (c) 2011 Elsevier Inc. 保留所有权利。
The objective of the present study was to characterize the capacity of zebrafish (Danio rerio) to regulate whole body Na+ levels during exposure to acidic (pH 3.8-4.0) water. Exposure to acidic water significantly affected the mRNA levels of 14 claudin and two occludin isoforms, tight junction proteins thought to be involved in regulating paracellular efflux. Despite these changes, Na+ efflux as well as uptake of polyethylene glycol (PEG), a marker for paracellular pathway, was persistently elevated during the 2-week period of acid exposure, although there was a transient recovery between 12- and 72-h. Pre-exposing fish to acidic water for 2 weeks failed to attenuate the increase in Na+ efflux associated with acute exposure to acidic water of low [Ca2+]. However, during recovery in water of circumneutral pH following exposure to acidic water, normal rates of Na+ efflux were restored within 5 h. The rate of Na+ uptake was significantly elevated between 4 and 7 days of exposure to acidic water; the increase was associated with significant increases in maximal Na+ uptake capacity (J(MAX)Na(+)) and affinity constant (K-M). These results demonstrate that in acidic water, zebrafish maintain their whole body Na+ balance primarily by regulating Na+ uptake, rather than Na+ efflux. (c) 2011 Elsevier Inc. All rights reserved.