Erythropoietin (EPO) Mike Lin

What is Erythropoietin? Hormone produced by the kidney (and liver) Promotes the formation of RBC’s by the bone marrow Kidney cells make EPO in response to low levels of oxygen in the blood Normal levels of EPO range from 4-24 mU/ml (milliunits per milliliter)

Structure of EPO A glycoprotein consisting of 165 amino acids

What does EPO do? EPO increases the oxygen carrying capacity of the blood: Promotes development of RBC’s Initiates synthesis of hemoglobin

EPO Mechanism

Feedback Pathway

Clinical Significance Abnormal EPO levels suggest disease of bone marrow or kidneys Too little: Anemia (too few RBCs) Too much: Polycythemia (too many RBCs) Synthetic EPO Therapy: Used to treat anemia from kidney failure or chemotherapy for cancer treatment Reduces need for blood transfusion in surgery Side Effect: increased risk of blood clots

EPO Blood Doping EPO is misused as a performance enhancing drug by athletes (More oxygen in the blood) Dehydration due to exercise can increase viscosity of blood Increases risk of clots, strokes, heart attacks

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