الفهرس 
HUMAN IRON METABOLISMOnly 14 pages are availabe for public view
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Abstract
Iron is a vital element in both humans and animals. Its important biological role in many metabolic processes and in critical enzyme reactions concerned with oxygen and electron transport and the cellular production of energy.
If iron concentrations is high this can be toxic, this lead to iron overload diseases which may cause organ damage. The synthesis and secretion of the hepatic hormone hepcidin is increased in response to liver iron overload and inflammation and is decreased in response to red cell demand or hypoxia. Most recessive diseases leading to primary iron overload known as HH result from inadequate hepcidin production leading to inappropriate iron accumulation. The mechanisms responsible for disturbed iron homeostasis in HH are poorly understood. However, results of some studies indicate a link between serum hepcidin, and intestinal iron absorption, suggesting that this molecule could play a part in hepatic iron overload toxicity.
Hepcidin is a peptide hormone that has a central negative regulatory role in systemic iron homeostasis through a hormonal action: digestive iron absorption by enterocytes and iron recycling by macrophages. Studies in humans have focused on the crucial role of hepcidin in the regulation of iron homeostasis. Dysregulation of hepcidin production results in a variety of iron disorders.
Summary and Conclusion
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Hepcidin production is mainly hepatic and to less extent extra-hepatic. Its elimination is renal and its expression is the result of the interplay between multiple stimuli including iron, inflammation, and erythropoiesis.
Hepcidin deficiency is the cause of iron overload in HH, iron-loading anemias and hepatitis C. Hepcidin excess is associated with AI, CKD and IRIDA.
Diagnostic and therapeutic applications of hepcidin hormone are beginning to emerge. Accordingly, hepcidin concentrations in different forms of anemia vary widely and may have diagnostic potential in differentiating between the various types of anemia. Furthermore, in cases where hepcidin is a causative factor of anemia, hepcidin-targeted therapies (Hepcidin agonists & Hepcidin antagonists) may improve treatment options for the patients.
Hepcidin agonists would be useful for preventing iron overload in nontransfused β-thalassemias and other iron-loading anemias.
Hepcidin antagonists would be expected to benefit patients with diseases of hepcidin excess. The curical role of hepcidin antagonists such as vitamin C, EPO and mono clonal antibodies will be a beneficial treatment of hypo-responsiveness to ESA therapy in ESRD patients and IRIDA.
Summary and Conclusion
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Importance role of hepcidin as a biochemical marker and a diagnostic tool in iron disorders such as anemias and iron overload syndromes, give insights about the clinical courses of these disorders. Hepcidin can be measured in urine, serum and plasma by different methods of assay; some assays detect hepcidin precursor prohormone (prohepcidin) as ELISA immunoassay and others detect mature hepcidin as RIA. Recent advances in quantitative serum and urine hepcidin measurements opened novel opportunities for studies on hepcidin in humans resulting in further insights in the clinical implications of hepcidin-mediated regulation of iron metabolism.
Nowadays it is so difficult to establish the best hepcidin assay for every application; each assay has potential advantages and disadvantages. The different methods of hepcidin assay have been used in a wide range of clinical conditions, giving insights that need to be further explored in the next future.
Finally we can concluded from our research essay; interestingly that the very important role of hepcidin as a key negative regulatory hormone in iron homeostasis and its clinical role as a future diagnostic biochemical marker in different types of anemias and HH, and as a therapeutic agent in treating more-complex iron metabolic and endocrine disorders, such as beta-thalassaemia, iron-loading anaemias, IRIDA, and anemia of inflammation.
Summary and Conclusion
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But still hepcidin clinical implications is in need to handling the limitations for its use due to technical difficulties and expensive cost and further wide clinical research works for both a better fully understanding of pathophysiology and for clinical purposes in which hepcidin will help.