PUBLICATION
Waterborne iron acquisition by a freshwater teleost fish, zebrafish Danio rerio
- Authors
- Bury, N.R. and Grosell, M.
- ID
- ZDB-PUB-030902-18
- Date
- 2003
- Source
- The Journal of experimental biology 206(19): 3529-3535 (Journal)
- Registered Authors
- Bury, Nicolas
- Keywords
- none
- MeSH Terms
-
- Animals
- Biological Transport, Active/drug effects
- Cadmium/pharmacology
- Dithiothreitol/pharmacology
- Fresh Water
- Gills/metabolism*
- Iron/metabolism
- Iron/pharmacokinetics*
- Macrolides/pharmacology
- Models, Biological*
- Zebrafish/metabolism*
- PubMed
- 12939383 Full text @ J. Exp. Biol.
Citation
Bury, N.R. and Grosell, M. (2003) Waterborne iron acquisition by a freshwater teleost fish, zebrafish Danio rerio. The Journal of experimental biology. 206(19):3529-3535.
Abstract
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] (<40 nmol l(-1)) the high-affinity component demonstrated saturation kinetics, with an apparent K(m) of 5.9 nmol l(-1) Fe and V(max) of 2.1 pmol g(-1) h(-1). Over a range of higher nominal [Fe] (40-200 nmol l(-1)), branchial uptake was linear. In the presence of 2 micro mol l(-1) of the reducing agent dithiothreitol (DTT), branchial iron accumulation was significantly enhanced at [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 Fe(2+)/H(+) symporter. Zebrafish branchial iron transport at 18.6 nmol l(-1) was inhibited by 200 nmol l(-1) Cd(2+). But, unlike other Fe(2+)/H(+) symporters, iron uptake was not affected by other divalent metals (Co(2+), Ni(2+), Pb(2+), Cu(2+), Zn(2+) and Mn(2+)). Zebrafish loaded with (59)Fe 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.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping