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Production of [[Erythrocytes|erythrocytes]] is regulated by '''erythropoietin''' (EPO) which is produced in the yolk sac, [[Liver - Anatomy & Physiology|liver]] and kidney from embryonic life until early neonatal life. In the adult it is produced only in the kidneys. Erythropoietin is a glycoprotein hormone and is controled by a negative feedback mechanism. Normal levels are low with sufficient amounts to maintain a basal level of new erythrocyte production. If blood oxygen concentration falls, the release of erythropoietin rises.
 
Production of [[Erythrocytes|erythrocytes]] is regulated by '''erythropoietin''' (EPO) which is produced in the yolk sac, [[Liver - Anatomy & Physiology|liver]] and kidney from embryonic life until early neonatal life. In the adult it is produced only in the kidneys. Erythropoietin is a glycoprotein hormone and is controled by a negative feedback mechanism. Normal levels are low with sufficient amounts to maintain a basal level of new erythrocyte production. If blood oxygen concentration falls, the release of erythropoietin rises.
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EPO is transported from kidneys to [[Bone Marrow - Anatomy & Physiology|bone marrow]] where it acts upon receptors on the CFU-E’s and causes differentiation into erythrocyte precursors. It also increases the rate of division and maturation of the developing erythrocyte precursors by increasing gene transcription. Thus it is not the number of [[Erythrocytes|erythrocytes]] but the oxygen concentration that regulates its release. EPO release can be affected by any form of renal pathology.
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EPO is transported from kidneys to [[Bone Marrow - Anatomy & Physiology|bone marrow]] where it acts upon receptors on the CFU-E’s and causes differentiation into erythrocyte precursors. It also increases the rate of division and maturation of developing erythrocyte precursors by increasing the rate of gene transcription. Thus it is not the number of [[Erythrocytes|erythrocytes]] but the oxygen concentration that controls erythrocyte numbers. EPO release can be affected by any form of renal pathology. Inflammatory induced release of interleukins reduces the secretion of erythropoietin.
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The mechanism of oxygen concntration detection is via HIF-1 (Hypoxia inducible factor 1) which is a transcription activator that is oxygen sensitive.
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===Factors involved===
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Erythropoietin production is directly and indirectly (via regulatory genes) increased by HIF-1 (Hypoxia inducible factor 1) which is a transcription activator that is oxygen sensitive.
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Inflammatory induced release of interleukins reduces the secretion of erythropoietin.
   
[[Category:Haematopoiesis]]
 
[[Category:Haematopoiesis]]
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