Erythropoietin is a hormone primarily produced in the kidneys. It is released into the blood flow in response to oxygen deprivation (hypoxia). Erythropoietin travels to the bone marrow, where it begins to stimulate the conversion of stem cells into red blood cells. Red blood cells contain hemoglobin – a protein that is able to carry oxygen from the lungs to organs and tissues. Normally, the lifespan of red blood cells is about 120 days, they have the same size and shape.
The body tries to maintain approximately the same number of circulating red blood cells. When the balance between the formation and destruction of red blood cells is destroyed, anemia develops. If too few red blood cells are formed in the bone marrow or too many are lost due to blood loss or destruction (hemolysis) caused by abnormal size, shape, function of red blood cells, or other reasons, then the amount of oxygen carried to the organs decreases. In response, the kidney produces erythropoietin, which is then delivered to the bone marrow by blood, where it stimulates the formation of red blood cells.
The production of red blood cells is influenced by the function of the bone marrow, the intake of sufficient amounts of ferrum, vitamin B12 and folic acid in food, as well as the formation of erythropoietin and the ability of the bone marrow to respond to appropriate amounts of this hormone.
The production of erythropoietin depends on the severity of oxygen deprivation and the ability of the kidneys to produce the hormone. It is active in the blood for a short time and then excreted in the urine. Once the number of red blood cells rises after a deficiency, the kidneys begin to produce less erythropoietin. However, if they are damaged and / or unable to produce enough erythropoietin, or if the bone marrow does not respond adequately to enough erythropoietin, anemia may develop.
When benign or malignant tumors of the kidneys (or other organs) form, an excessive amount of erythropoietin is produced, which causes too many red blood cells – polycythemia develops. This leads to an increase in the circulating blood volume, an increase in its viscosity and blood pressure.
To distinguish different types of anemia from each other and to find out how the level of erythropoietin corresponds to the severity of anemia. The need for this study, as a rule, is due to some abnormalities in the general blood test, which includes the determination of the number of erythrocytes (red blood cells), hemoglobin, hematocrit, reticulocytes. The results of such an analysis make it possible to confirm the diagnosis of “anemia”, to determine the degree of its severity and the cause of it.
To find out if the anemia is caused by a lack of erythropoietin or if this lack is aggravating the existing anemia of another origin. To assess the ability of the kidneys to produce adequate amounts of erythropoietin in patients with chronic renal failure. To find out if polycythemia is caused by excess production of erythropoietin.