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Intestinal Iron Absorption
Dietary iron absorption takes place at the apical membrane of mature enterocytes. In hereditary hemochromatosis, increased iron absorption leads to the gradual accumulation of iron to levels that eventually become toxic. The iron regulatory protein HFE has been implicated in this process (1).
Enterocyte iron absorption mechanismsClick on a protein (in blue) to learn more.
DMT1
Ferritin
Ferroportin
Transferrin receptor
Intestinal Iron Absorption
Monitor Serum Ferritin
In both primary
and secondary iron overload, serum
ferritin >1000 mcg/L
is associated with worsened prognosis.
After its enzymatic reduction from Fe+3 to Fe+2, iron is imported into the cell by the divalent metal transporter protein (2). Iron can either be stored within the cell as ferritin, or transferred into the blood at the basolateral membrane by ferroportin (IREG1) (3). Plasma-borne iron binds to transferrin, and is available for distribution via the blood.
How hepatocytes efficiently acquire and store iron
References
- (1) Pietrangelo A, Camaschella C, Molecular genetics and control of iron metabolism in hemochromatosis. Haematologica. 1998;83(5):456-61.
- (2) Andrews NC, The iron transporter dmt1. Int J Biochem Cell Biol. 1999;31(10):991-4.
- (3) Zoller H, Theurl I, Koch R, et al., Mechanisms of iron mediated regulation of the duodenal iron transporters divalent metal transporter 1 and ferroportin 1. Blood Cells Mol Dis. 2002;29(3):488-97.