iron metabolism


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iron metabolism

a series of processes involved in the entry of iron into the body and its absorption, transport, storage, use in the formation of hemoglobin and other iron compounds, and eventual excretion. Iron normally enters through the intestinal mucosa and is oxidized from ferrous to ferric iron in the process. The rate at which iron enters is modulated by this absorption mechanism. When iron stores are high, iron no longer passes through but is trapped by the mucosal cells of the intestine to be eliminated. Once in the blood, iron cycles between the plasma and the reticuloendothelial or erythropoietic system. For hemoglobin synthesis, plasma iron is delivered to the normoblast, where it remains up to 4 months, functioning in the hemoglobin molecules of a mature red cell. Senescent red cells then deteriorate. The iron is released from the hemoglobin by the reticuloendothelial system to reenter the transport pool for recycling. The normal iron distribution in a 70-kg adult (male) totals approximately 3.7 g, more than 65% in circulating hemoglobin. Another 27% is found in the storage pool as hemosiderin or ferritin. The body normally conserves iron so well that loss, usually only through the feces, is normally limited to about 1 mg/day. This amount is easily provided by a dietary intake of only 10 mg/day. Iron deficiency may follow extended intervals of inadequate iron intake (especially in women), in pregnancy when higher levels of iron are needed, or with excessive blood loss. Iron overload sometimes occurs in disorders in which normal regulation of iron absorption is impaired, called hemochromatosis. Hemochromatosis may be inherited or acquired in long-term transfusion therapy for chronic anemias. See also anemia, hemochromatosis, iron deficiency anemia, iron transport.

iron me·tab·o·lism

(ī'ŏrn mĕ-tab'ŏ-lizm)
The sum of the chemical and physical processes whereby iron is introduced into or evacuated from the body.
References in periodicals archive ?
Shift to kidneys In recent years, researchers have revealed that system-wide iron metabolism is watched over by certain organs, with most focus to date on the liver and the intestines.
However, no differences were observed in the two groups related to the remaining iron metabolism variables and medications (Table 1).
Other factors under study include iron metabolism and neurotransmitter dysfunctions involving dopamine and glutamate.
The data suggest that AD may involve disturbances in brain iron metabolism and that the involvement of iron in the pathophysiology of age-related neurodegenerative disorders can be investigated in vivo using MRI.
A decrease in the levels of CSF Tf reflects the imbalance of brain's iron metabolism that is associated with sCJD.
Fifty-two contributed chapters begin with coverage of stem cells and haemopoiesis, erthropoiesis, iron metabolism and disorders of haem synthesis, iron overload, and megaloblastic anaemia; the collection concludes with primary immune thrombocytopenia, haemtological aspects of system disease, and of tropical diseases, and neonatal haematology.
Hepcidin, a peptide produced by the liver and encoded by the HAMP gene, has been found to play a central role in iron metabolism and homeostasis.
JUVENILE HEMOCHROMATOSIS: SIGNAL TRANSDUCTION AND IRON METABOLISM
Disorders of iron metabolism and sideroblastic anemia in Nathan and Oski's Hematology of infancy and childhood.
The link with dysfunctional iron metabolism would explain the high prevalence of RLS in anemia or uremia, as well as in pregnancy.
Interfering with iron metabolism by administering gallium can be useful in suppressing growth of lymphoma and bladder cancer cells (36).