Mechanism of acid adaptation of a fish living in a pH 3.5 lake
Mechanism of acid adaptation of a fish living in a pH 3.5 lake
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DOI：
10.1152/ajpregu.00267.2002
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发表时间：
2003-05-01
影响因子：
2.8
通讯作者：
Hirose, S
中科院分区：
文献类型：
--
作者：
Hirata, T;Kaneko, T;Hirose, S
尽管条件不利，一种单一的鱼，Osorezan dace，生活在一个极酸性的湖泊（pH值3.5）在Osorezan，青森，日本。生理学研究已经确定，这种鱼能够防止其血浆酸化和Na+的损失。在这里，我们表明，这些能力主要是由于氯细胞的鳃，这是安排在一个滤泡结构，并含有高浓度的Na+-K+-ATP酶，碳酸酐酶II，3型Na+/H+交换器（NHE 3），1型Na+-HCO 3- cotransporter，和水通道蛋白3，所有这些都上调酸化。免疫组织化学确定了它们的氯细胞定位，NHE 3位于顶面，其他位于基底外侧膜。这些结果表明Osorezan Dace适应其酸性环境的机制。最有可能的是，顶侧的NHE 3分泌H+以交换Na+，而基底外侧膜中的产电1型Na+-HCO 3-共转运蛋白使用Na+-K+-ATP酶和碳酸酐酶II产生的驱动力提供HCO 3-以中和血浆。谷氨酸脱氢酶的表达增加，也观察到在各种组织的酸适应性？
Despite unfavorable conditions, a single species of fish, Osorezan dace, lives in an extremely acidic lake (pH 3.5) in Osorezan, Aomori, Japan. Physiological studies have established that this fish is able to prevent acidification of its plasma and loss of Na+. Here we show that these abilities are mainly attributable to the chloride cells of the gill, which are arranged in a follicular structure and contain high concentrations of Na+-K+-ATPase, carbonic anhydrase II, type 3 Na+/H+ exchanger (NHE3), type 1 Na+-HCO3- cotransporter, and aquaporin-3, all of which are upregulated on acidification. Immunohistochemistry established their chloride cell localization, with NHE3 at the apical surface and the others localized to the basolateral membrane. These results suggest a mechanism by which Osorezan dace adapts to its acidic environment. Most likely, NHE3 on the apical side excretes H+ in exchange for Na+, whereas the electrogenic type 1 Na+-HCO3- cotransporter in the basolateral membrane provides HCO3- for neutralization of plasma using the driving force generated by Na+-K+-ATPase and carbonic anhydrase II. Increased expression of glutamate dehydrogenase was also observed in various tissues of acid-adapted dace, suggesting a significant role of ammonia and bicarbonate generated by glutamine catabolism.