Waterborne iron acquisition by a freshwater teleost fish, zebrafish Danio rerio
Waterborne iron acquisition by a freshwater teleost fish, zebrafish Danio rerio
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DOI：
10.1242/jeb.00584
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发表时间：
2003-10-01
影响因子：
2.8
通讯作者：
Grosell, M
中科院分区：
文献类型：
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作者：
Bury, NR;Grosell, M
研究了斑马鱼鱼鳃在水中的铁积累。鳃铁摄取包括进入鳃细胞的铁和与上皮紧密结合的铁，有高亲和力和低亲和力成分。在低标称[Fe] （15 nmol l(-1)）下。质子泵抑制剂巴菲霉素A在DTT存在下显著降低铁摄取。基于这些观察，我们得出结论，低[Fe]时的鳃铁摄取表现出与其他铁转运上皮相似的特征，将顶端膜铁还原酶偶联到Fe2+/H+同调体。200 nmol l(-1) Cd2+可抑制18.6 nmol l（-1）的斑马鱼鳃铁转运。但与其他Fe2+/H+同运体不同，铁的吸收不受其他二价金属（Co2+、Ni2+、Pb2+、Cu2+、Zn2+和Mn2+）的影响。从水中加载了Fe-59的斑马鱼在第一天的体重损失了7.9 pmol的铁g(-1)，在接下来的28天里进一步损失了5.7 pmol的铁g（-1）。净化动力学遵循双组分指数模型；对于短寿命成分，t(1/2)=0.31天，对于长寿命成分，t(1/2)=13.2天。斑马鱼每天的铁损失可以通过在极低的水中铁浓度(吸收率为1.625 nmol l(-1) Fe=0.425 pmol g（-1) h(-1)）下的铁吸收来弥补，这表明从水中吸收铁是淡水硬骨鱼这种营养金属的潜在重要来源。
Waterborne iron accumulation by the gills of the zebrafish Danio rerio was assessed in ion-poor water. Branchial iron uptake, which comprises both the iron that has entered the gill cells and iron that is strongly bound to the epithelia, has high- and low-affinity components. At low nominal [Fe] (15 nmol l(-1). The proton pump inhibitor bafilomycin A significantly reduced iron uptake in the presence of DTT. On the basis of these observations we conclude that branchial iron uptake at low [Fe] shows characteristics similar to those of other iron-transporting epithelia, coupling an apical membrane ferric reductase to a Fe2+/H+ symporter. Zebrafish branchial iron transport at 18.6 nmol l(-1) was inhibited by 200 nmol l(-1) Cd2+. But, unlike other Fe2+/H+ symporters, iron uptake was not affected by other divalent metals (Co2+, Ni2+, Pb2+, Cu2+, Zn2+ and Mn2+). Zebrafish loaded with Fe-59 from the water showed a loss of 7.9 pmol Fe g(-1) body mass over the first day and a further loss of 5.7 pmol Fe g(-1) body mass over the following 28 days. The depuration kinetics followed a two-component exponential model; for the short-lived component, t(1/2)=0.31 days, and for the long-lived component, t(1/2)=13.2 days. The daily iron loss by zebrafish can be compensated by iron uptake at exceedingly low water iron concentrations (uptake rate at 1.625 nmol l(-1) Fe=0.425 pmol g(-1) h(-1)), demonstrating that uptake of iron from the water is potentially an important source of this nutritive metal in freshwater teleost fish.