适应淡水的罗非鱼（莫桑比克罗非鱼）的氯离子摄取机制。

Cl- uptake mechanism in freshwater-adapted tilapia (Oreochromis mossambicus).

作者信息

Chang I-Chi, Hwang Pung-Pung

机构信息

Institute of Fisheries Science, National Taiwan University, Taipei, Taiwan, Republic of China.

出版信息

Physiol Biochem Zool. 2004 May-Jun;77(3):406-14. doi: 10.1086/383505.

DOI:10.1086/383505

PMID:15286914

Abstract

In this study, the correlation between Cl(-) influx in freshwater tilapia and various transporters or enzymes, the Cl(-)/HCO(3)(-) exchanger, Na(+),K(+)-ATPase, V-type H(+)-ATPase, and carbonic anhydrase were examined. The inhibitors 2x10(-4) M ouabain (a Na(+),K(+)-ATPase inhibitor), 10(-5) M NEM (a V-type H(+)-ATPase inhibitor), 10(-2) M ACTZ (acetazolamide, a carbonic anhydrase inhibitor), and 6x10(-4) M DIDS (a Cl(-)/HCO(3)(-) exchanger inhibitor) caused 40%, 60%-80%, 40%-60%, and 40%-60% reduction in Cl(-) influx of freshwater tilapia, respectively. The inhibitor 2x10(-4) M ouabain also caused 50%-65% inhibition in gill Na(+),K(+)-ATPase activity. Western blot results showed that protein levels of gill Na(+),K(+)-ATPase, V-type H(+)-ATPase, and carbonic anhydrase in tilapia acclimated in low-Cl(-) freshwater were significantly higher than those acclimated to high-Cl(-) freshwater. Based on these data, we conclude that Na(+),K(+)-ATPase, V-H(+)-ATPase, the Cl(-)/HCO(3)(-) exchanger, and carbonic anhydrase may be involved in the active Cl(-) uptake mechanism in gills of freshwater-adapted tilapia.

摘要

在本研究中，检测了淡水罗非鱼中氯离子内流与各种转运蛋白或酶（氯离子/碳酸氢根离子交换体、钠钾ATP酶、V型氢离子ATP酶和碳酸酐酶）之间的相关性。抑制剂2×10⁻⁴ M哇巴因（一种钠钾ATP酶抑制剂）、10⁻⁵ M NEM（一种V型氢离子ATP酶抑制剂）、10⁻² M ACTZ（乙酰唑胺，一种碳酸酐酶抑制剂）和6×10⁻⁴ M DIDS（一种氯离子/碳酸氢根离子交换体抑制剂）分别使淡水罗非鱼的氯离子内流减少了40%、60%-80%、40%-60%和40%-60%。抑制剂2×10⁻⁴ M哇巴因还使鳃部钠钾ATP酶活性受到50%-65%的抑制。蛋白质印迹结果显示，适应低氯淡水的罗非鱼鳃部钠钾ATP酶、V型氢离子ATP酶和碳酸酐酶的蛋白水平显著高于适应高氯淡水的罗非鱼。基于这些数据，我们得出结论，钠钾ATP酶、V型氢离子ATP酶、氯离子/碳酸氢根离子交换体和碳酸酐酶可能参与了适应淡水的罗非鱼鳃部主动摄取氯离子的机制。