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 he althy people varies over a wide range and is inversely related to the concentration of hemoglobin and the degree of tissue oxygenation. The work of isolating and producing this hormone for medical purposes is very rewarding.
Structure and meaning of the hormone
The hormone molecule consists of amino acids. With a deficiency of endogenous erythropoietin, a sharp decrease in the level of hemoglobin and erythrocytes in the blood is observed, the so-called erythropoietin deficiency anemia develops. BeforeRecently, drug correction of such anemia has 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. Recombinant human erythropoietin is identical in amino acid and carbohydrate composition to the natural hormone, increases the number of red blood cells, reticulocytes, and activates hemoglobin biosynthesis in cells. The biological activity of the resulting substance is no different from the endogenous hormone. Recombinant erythropoietin does not show cytotoxic effects and does not affect leukopoiesis. Scientists suggest that EPO interacts with specific erythropoietin-sensitive receptors that are localized on the cell surface.
Purification method for recombinant human erythropoietin
Recombinant human EPO is one of the most widely used 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 using recombinant DNA. One polypeptide chain of recombinant EPO contains 165 amino acids, the estimated molecular weight of which is 24,000 Da, and the observed molecular weight of the glycosylated protein is 30,400 Da. The separation of erythropoietin from impurities is carried out using ion-exchange and affinitychromatography. Human recombinant EPO is 98% pure.
Recombinant erythropoietins and their analogues
To stimulate the processes of erythropoiesis, doctors use different drugs:
- Aranesp;
- Aeprin;
- Epobiocrine;
- Bioein;
- Vepox;
- "Binocrit";
- "Epocrine";
- Gemax;
- "Epogen";
- Eprex;
- "Epovitan";
- Epomax;
- "Hypercrit";
- Eralfon;
- Erythrostim;
- "Recormon";
- Epostim;
- Eposino;
- Epoetin Beta.
Before replacing recombinant erythropoietin with analogues, you should consult with your doctor.
Indications for use
Erythropoietin deficiency anemia (EDA) is quite common for medical practitioners. This group includes the following pathologies:
- anemia in malignant neoplasms;
- early anemia of premature babies (before 34 weeks of gestation) weighing 750 to 1500 g;
- nephrogenic anemia;
- anemia in chronic diseases (hepatitis C, rheumatoid arthritis, HIV infection, diseases of the alimentary canal).
A distinctive feature of the above anemias is that they are not treated with iron supplements. Until recently, blood transfusions were the only effective method of therapy. Due to the fact that this type of therapy has a huge number of side effectsand 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 improve the quality of life for patients diagnosed with erythropoietin deficiency anemia. Biosynthesis and introduction of recombinant human EPO into practice opened a new era in the treatment of erythropoietin-dependent anemia.
Contraindications
Doctors do not recommend the use of recombinant erythropoietin (the instructions warn about this) in the presence of the following pathologies:
- thromboembolism;
- drug hypersensitivity;
- impossibility of effective anticoagulant therapy;
- past cerebral stroke or myocardial infarction;
- unstable angina;
- uncontrolled hypertension;
- bearing and breastfeeding period;
- refractory arterial hypertension.
Dosing regimen
The dosage, regimen and duration of treatment are set on a strictly individual basis, depending on the severity of anemia, the general condition of the patient and the nature of the pathology. The preparations are intended for parenteral use. Initial doses range from 50 to 150 IU/kg. The dose must be adjusted according to the age of the patient. Recombinant erythropoietin is usually administered 3 times a dayweek. With an overdose of the drug, there is an increase in side effects. The result becomes more or less noticeable after 2-3 weeks of use.
Side effect
Are you prescribed recombinant human erythropoietin? Instructions for use does not exclude the development of side effects. This is:
- myalgia;
- dizziness;
- hyperthermia;
- drowsy;
- vomit;
- headache;
- diarrhea;
- arthralgia;
- hypertension;
- chest pain;
- thrombocytosis;
- tachycardia;
- hypertensive crisis;
- convulsions;
- hepatosis;
- increase in the level of activity of AST, ALT in the blood;
- RBC aplasia;
- eczema;
- angioedema;
- skin rash and itching;
- asthenia;
- urticaria, hyperemia and burning at the injection site;
- hyperkalemia;
- decrease in plasma ferritin protein concentration;
- hyperphosphatemia.
Erythropoiesis stimulants in sports
Recently, the drug "Epovitan" (recombinant human erythropoietin) is often used. The presented tool is often used in sports (athletics, bodybuilding, swimming, biathlon). This drug activates the biosynthesis of erythrocytes, which, in turn, leads to an increase in the oxygen content per unit volume of blood and, accordingly, to an increase in the oxygen capacity of the blood and deliveryO2 to organs and tissues. This mechanism of action increases the aerobic endurance of the athlete. A similar effect is observed when an athlete trains in mid-mountain conditions, when the lack of O2 in the air provokes the development of hypoxia, which, in turn, activates the biosynthesis of endogenous erythropoietin. EPO preparations are used in combination with insulin, growth hormone (GH, growth hormone) and stanazolol.
Excessive, uncontrolled use of the drug "Erythropoietin" in sports can provoke the formation of blood clots, which is usually fatal. It is rather difficult to detect recombinant EPO, since the structure of the synthetic compound is identical to its physiological counterpart, therefore this biocompound is still illegally used in professional sports as a doping.
