Abstract
Iron is an essential element playing a vital role in many cellular processes. This requirement is complicated by the fact that environmental iron is invariably present as insoluble Fe3+ leading to poor bioavailability and toxicity, since even low concentrations of iron catalyse the production of damaging reactive oxygen species. As a result organisms have evolved efficient uptake and transport systems to extract iron from their environment as well as ferritins that store iron in a non-toxic form. In higher organisms, the first membrane barrier encountered is the apical surface of the duodenal enterocyte, a specialized absorptive cell of the intestinal epithelium that undertakes vectorial transport of iron. Iron is initially solubilized by reduction and Fe2+ is transported across the cell membrane by a carrier-mediated transport process. This is followed by intracellular transfer of iron to the basolateral enterocyte membrane with subsequent transfer and release of iron to transferrin in the portal blood. A second site of iron transport is at the placento-fetal barrier where similar principles operate. In this review we describe recently identified transmembrane transporters and associated accessory proteins responsible for iron transport at these two sites.
Original language | English |
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Pages (from-to) | 243-259 |
Number of pages | 17 |
Journal | Best Practice & Research Clinical Obstetrics & Gynaecology |
Volume | 15 |
Issue number | 2 |
DOIs | |
Publication status | Published - Jun 2002 |
Keywords
- DMT1
- IREG1
- MTP1
- hephaestin
- ferric red uctase (Dcytb)
- HFE
- apical membrane
- basolateral membrane
- hereditary haemochromatosis
- ferritin
- transferrin
- transferrin receptor
- iron transporters
- crypt cell
- enterocyte
- epithelial cell
- ferroportin
- iron overload
- iron deficiency
- syncytiotrophoblast
- placenta
- hereditary hemochromatosis protein
- autosomal-dominant hemochromatosis
- metal-ion transporter
- transferrin receptor
- idiopathic hemochromatosis
- genetic hemochromatosis
- ceruloplasmin homolog
- plasma-membrane
- small-intestine
- CACO-2 cells