Erythropoietin (EPO) is a glycoprotein hormone that controls the rate of erythropoiesis in the human body. The presented substance is synthesized mainly in the kidneys, a small amount (about 10 percent) is formed in the liver. The hormone erythropoietin activates the division and differentiation of erythroid precursors. The level of endogenous hormone in the blood plasma of healthy people varies in a wide range and is inversely related to the concentration of hemoglobin and the degree of tissue oxygenation. Work on the isolation and production of this hormone for medical purposes is very useful.
The structure and meaning of the hormone
The hormone molecule is composed of amino acids. With a deficiency of endogenous erythropoietin, a sharp decrease in the level of hemoglobin and red blood cells in the blood is observed, the so-called erythropoietin deficiency anemia develops. Until recently, the medical correction of such anemia remained impossible due to the lack of an appropriate pharmaceutical agent. Nowadays, with a deficiency of the above hormone in the human body, doctors prescribe recombinant erythropoietin. The drug is obtained from animal cells into which the human EPO gene code is introduced. The recombinant human erythropoietin is identical in its amino acid and carbohydrate composition to the natural hormone, increases the number of red blood cells, reticulocytes, and activates the hemoglobin biosynthesis in cells. The biological activity of the resulting substance is no different from endogenous hormone. Recombinant erythropoietin does not exhibit a cytotoxic effect and does not affect leukopoiesis. Scientists suggest that EPO interacts with specific erythropoietin-sensitive receptors that localize on the surface of the cell.
The method of purification of recombinant human erythropoietin
Recombinant human EPO is one of the most abundant proteins produced by many biological and pharmaceutical companies around the world for drug therapy. The present compound is synthesized by Chinese Hamster Ovary (CHO) cells by recombinant DNA. One recombinant EPO polypeptide chain contains 165 amino acids, with a calculated molecular weight of 24,000 Da and an observed molecular weight of glycosylated protein of 30,400 Da. The separation of erythropoietin from impurities is carried out using ion exchange and affinity chromatography. Human recombinant EPO has a purity of 98%.
Recombinant erythropoietins and their analogues
To stimulate the processes of erythropoiesis, doctors use different drugs:
- Aranesp;
- Aerin;
- "Epobiocrin";
- "Bioein";
- Vepox;
- "Binocrit";
- "Epocrine";
- Gemax;
- "Epogen";
- Eprex;
- "Epovitan";
- Epomax
- "Hypercrit";
- Eralfon;
- Erythrostim;
- Recormon
- "Epostim";
- "Epozino";
- Epoetin Beta.
Before replacing recombinant erythropoietin with analogues, you should consult your doctor.
Indications for use
Practicing doctors quite often have to deal with erythropoietin-deficiency anemia (EDA). This group includes the following pathologies:
- anemia in malignant neoplasms;
- early anemia of premature babies (up to 34 weeks of pregnancy) with a body weight of 750 to 1500 g;
- nephrogenic anemia;
- anemia in chronic diseases (hepatitis C, rheumatoid arthritis, HIV infection, diseases of the digestive canal).
A distinctive feature of the above anemias is that they are not treated with iron preparations. Until recently, the only effective method of therapy was blood transfusion. Due to the fact that this type of therapy has a huge number of side effects and a high risk of transmission through the blood of pathogens of a number of dangerous infectious diseases (HIV, hepatitis viruses, etc.), this method is practically not used in modern medicine. Recombinant human erythropoietin helps to improve the quality of life for patients diagnosed with erythropoietin deficiency anemia. The biosynthesis and introduction of recombinant human EPO into practice has ushered in a new era in the treatment of erythropoietin-dependent anemia.
Contraindications
Doctors do not recommend the use of recombinant erythropoietin (the instruction warns about this) in the presence of the following pathologies:
- thromboembolism;
- hypersensitivity to the drug;
- the inability to conduct effective anticoagulant therapy;
- cerebral stroke or myocardial infarction;
- unstable angina pectoris;
- uncontrolled arterial hypertension;
- the period of bearing a child and breastfeeding;
- refractory arterial hypertension.
Dosage regimen
Dosage, schedule and duration of treatment are established in a strictly individual order, depending on the severity of anemia, the general condition of the patient and the nature of the pathology. The drugs are intended for parenteral use. Initial doses range from 50 to 150 IU / kg. The dose must be adjusted depending on the age of the patient. Recombinant erythropoietin is usually administered 3 times a week. With an overdose of the drug, an increase in side effects is observed. The result becomes more or less noticeable after 2-3 weeks of use.
Side effect
Have you been assigned to recombinant human erythropoietin? Instructions for use do not exclude the development of side effects. It:
- myalgia;
- dizziness;
- hyperthermia;
- drowsiness;
- vomiting
- headache;
- diarrhea;
- arthralgia;
- hypertension;
- chest pain;
- thrombocytosis;
- tachycardia;
- hypertensive crisis;
- cramps
- hepatosis;
- increased levels of AST, ALT in the blood;
- erythrocyte germ;
- eczema;
- angioedema;
- skin rash and itching;
- asthenia;
- urticaria, hyperemia and burning at the injection site;
- hyperkalemia
- a decrease in the concentration of ferritin protein in blood plasma;
- hyperphosphatemia.
Stimulants of erythropoiesis in sports
Recently, the drug "Epovitan" (recombinant human erythropoietin) is often used. The presented remedy is often used in sports (athletics, bodybuilding, swimming, biathlon). The specified drug activates the biosynthesis of red blood cells, which, in turn, leads to an increase in oxygen content per unit volume of blood and, accordingly, to an increase in the oxygen capacity of blood and the delivery of O 2 to organs and tissues. This mechanism of action increases aerobic endurance in an athlete. A similar effect is observed during athlete training in the midlands, when a lack of O 2 in the air provokes the development of hypoxia, which, in turn, activates the biosynthesis of endogenous erythropoietin. EPO drugs are used in combination with insulin, somatotropin (STH, growth hormone) and stanazolol.
Excessive, uncontrolled use of the drug "Erythropoietin" in sport can trigger the formation of blood clots, which usually leads to death. It is quite difficult to detect recombinant EPO, since the structure of the synthetic compound is identical to its physiological analogue, therefore, this bio-compound is still illegally used in sports as doping.