About Erythropoietin

Erythropoietin is a hormone that is produced, although the liver and macrophages make small contributions by the kidneys.

Description

Erythropoietin acts on the bone marrow where it stimulates the production of red blood cells. Erythropoietin is also called hematopoietic and is a glycoprotein.

The synthesis in the kidneys depends on the amount of available oxygen in the blood, which is flowed through the kidney. Unlike the breathing and heart rate, this control is relatively slow: it can take in blood loss or lack of oxygen hours before has set a new equilibrium. In cases of anemia, the erythropoietin synthesis stimulated. Decreasing the hematocrit erythropoietin increases exponentially. Erythropoietin can be manufactured in laboratories and is a form of rhEPO (recombinant human erythropoietin) known under brand names such as Eprex, Mircera etc.

Originally, the substance was synthesized as a drug for people with poor or non-functioning kidney, artificial kidney treatment despite nearly all got anemia due to lack of erythropoietin. By giving this the anemia could be corrected. Cancer patients can also myelodysplasia or erythropoietin is administered gain against anemia, during the chemotherapy, it is necessary, because red blood cells are destroyed. By the chemotherapy into the body

It is also administered as a form of drugs, in order to increase. The oxygen and carbon dioxide-carrying capacity of blood.

Risks

One of the risks of administering erythropoietin is that the blood can be (an artificial polycythemia). Viscous As a result, the user runs an increased risk of thrombosis.

Since 2000, there are urine tests that erythropoietin use can be detected directly. Through this test include mountain bikers Filip Meirhaeghe and Bas van Dooren and cyclo-cross rider Ben Berden caught.

In addition to the urine test is also used to still another test, the hematocrit test, was introduced in 1997 and is still in use. In this test erythropoietin-use is not directly detected, but its effect is measured: hematocrit. Because the hematocrit except through Erythropoietin-use also by construction, dehydration or living at altitude is affected, this test is officially designated as 'health check'. If a value is found above 50%, then the athlete taken out of the competition two weeks. Athletes who naturally have a high hematocrit may, after examination given dispensation.

Erythropoietin


Various forms of erythropoietin

There are several generations of Erythropoietin. In 1977, small amounts of erythropoietin could be isolated from the urine of patients with aplastic anemia for the first time; the first generation of erythropoietin. The second generation, from 1987, is a epovariant that using genetic techniques produced the so-called recombinant human erythropoietin (rhEPO). An important advantage is that this means easy in larger quantities to produce. Darbepoetin alfa (Aranesp) is a chemically modified variant erythropoietin, with the advantage that they must be injected less frequently. The aim of the development of the third generation erythropoietin was to find a means that does not have to be administered. Only every 3 to 4 weeks In 2007 Continuous erythropoiesis receptor activator (Cera), brand name Mircera, came on the market. All of these forms of erythropoietin are detectable in urine and / or blood.

There is also a fourth generation epo coming. The fourth generation would not detect because these agents are still in clinical trials. This relates to forms of gene therapy. One of those ways is to be set up to produce. Erythropoietin by using an adenovirus with a piece of erythropoietin-DNA, human cells This effect can also be obtained by injection of naked DNA, or artificial human chromosomes.

Other recent developments include the production of substances that do not appear in chemical structure to epo but have about the same effect, because they like erythropoietin engaging the erythropoietin receptor. These can be small molecules ("small molecules") or (small) peptides called erythropoietin mimetic peptides (MPCs). One of these peptides is Hematide. One need is likely to be injected. Only once per month Side effects and effectiveness are still unknown. The drug is expected that in 2009 the market.

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