Regulation of erytropioesis

Regulation of erytropioesis

1. Regulation of erythropoiesis General factors Hypoxia  erythropoietin Growth inducers Vitamins Maturation factors Vitamin B 12 Folic acid Factors necessary for hemoglobin production - Vitamin C  Helps in iron absorption (Fe+++  Fe++) - Proteins  Amino Acids for globin synthesis - Iron & copper  Heme synthesis - calcium, bile salts, cobalt & nickel.

2. General factors Hypoxia  erythropoietin

3. EPO Erythropoietin  (EPO) is a hormone produced by the kidney that promotes the formation of red blood cells by the bone marrow. The kidney cells that make erythropoietin  are sensitive to low oxygen levels in the blood that travels through the kidney.

4. Erythropoietin (EPO) facts Erythropoietin (EPO) is a hormone produced by the kidney. Erythropoietin promotes the formation of  red blood cells  by the bone marrow. The erythropoietin hormone level can be detected and measured in the blood (the EPO test ). 4 up to 24 mU /m Measurement of the blood erythropoietin level can be used to detect certain medical conditions. Erythropoietin can be synthesized and used as a treatment of some forms of  anemia . Erythropoietin has been misused as a performance-enhancing drug by some athletes.

5. ERYTHROPOIETIN Glycoprotein MW-34000 (165 AA residues) Formation 85% formed in endothelial cells of the peritubular capillaries of the renal tubules. 15% formed in liver, hepatic cells & Kupffer cells. Breakdown In liver. Half life is 5hours

6. Function Erythropoietin stimulates the bone marrow to produce more red blood cells. The resulting rise in  red cells  increases the oxygen-carrying capacity of the blood. As the prime regulator of red cell production, erythropoietin's major functions are to: Promote the development of red blood cells. Initiate the synthesis of hemoglobin, the molecule within red blood cells that transports oxygen.

7. uses uses of erythropoietin may include treatment of anemia related to the medication AZT (used to treat AIDS ), anemia caused by  chemotherapy , anemia caused by dysfunctional bone marrow (where the blood cells are made), and anemia associated with  cancer

8. Regulation of erythropoietin secretion O 2 sensor ( heme protein) in kidney & liver Deoxy & oxy form of O 2 sensor HYPOXIA INDUCIBLE FACTOR-1 (HIF-1) Erythropoietin gene Erythropoietin mRNA Erythropoietin 2-3 days to increase RBC count

9. ERYTHROPOEITIN Stimuli for production Hypoxia Products of RBC destruction High altitude Anemia Chronic lung or heart diseases Catecholamines ” neurotransmitters such as adrenaline and dopamine .” Prostaglandins Androgens Inhibition Blood transfusion

10. Functions of Erythropoietin Erythropoietin increases RBC production in 3 ways: Promotes pronormoblast production Shortens the transition time through the normoblast stage Promotes the early release of reticulocytes.

11. Growth inducers/ Differentiation inducers Interleukin 1, 3, 6 (IL-3 is a growth inducer for all cell lines ) CSF- E (colony stimulating factor – erythro)

12. Maturation factors Vitamin B 12 Folic acid Dietary factors - IRON

13. Vit B-12 Source : only animal tissues Absorption from ileum Functions Promotes maturation of RBCs (plays an important role in folic acid synthesis of nucleic acid-DNA)

14. Sources of vitamin B12 16

15. Folic acid Green leafy vegetables , yeast, liver Function : maturation of RBC

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17. IRON DEFICENCY ANEMIA