Regulation of “Iron absorption”
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■ Duodenal epithelial cell uptake of heme and nonheme iron is depicted.
■ When the storage sites of the body are replete with iron and erythropoietic activity is normal, plasma hepcidin levels are high.
This leads to down-regulation of ferroportin and trapping of most of the absorbed iron, which is lost when duodenal epithelial cells are shed into the gut.
■ Conversely, when body iron stores decrease or when erythropoiesis is stimulated, hepcidin levels fall and ferroportin activity increases, allowing a greater fraction of the absorbed iron to be transferred to plasma transferrin.
( ******DMT1, Divalent metal transporter 1).
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