The human body consists of numerous systems that work simultaneously. All of the body system is made to work by the abundant cells and number of organs. This ensures that humans are able to live and survive in the many environments or conditions affecting a human’s life. One of the systems known as the blood circulation system provides oxygen and nutrients on cellular level in the body. It also eliminates waste products from the body. The blood systems do not only involve the 100 000 kilometres long of blood vessels but also the heart as its engine. Ask a doctor and you will know how important the blood system is to a human’s viability. In this article, we will be learning about hepcidin.
What does hepcidin have to do with the blood system? Hepcidin is a hormone produced by the liver and is released to the blood system. It is known as the master regulator of systemic iron homeostasis that controls the production of the red blood cells. Systemic iron homeostasis involves iron absorption through the intestine. It also works to regulate the flow of iron from cells into the system circulation (the blood circulation affecting the steadiness of internal and chemical conditions inside humans). It helps maintain the iron balance in the body by controlling the way the body utilises the iron supply. Iron is needed for production of haemoglobin (a protein in red blood cells). Haemoglobin is vital for ensuring the ability of the red blood cells to transport oxygen in the blood from the lungs to the tissue.
Hepcidin regulates the iron in the body by preventing the process from the body absorbing iron. Hepcidin acts on a protein called ferroportin. Ferroportin is also known as an iron exporter. An iron exporter works by obtaining and transferring iron between cells. Thus, when hepcidin acts on ferroportin, it leads to degradation or breakdown of the ferroportin that prevent iron entry into the bloodstream from being absorbed into the small intestine. This alone makes hepcidin to be known as an iron regulator.
What stimulates hepcidin release? Hepcidin release is stimulated by the level of iron excess in the human body. This will enable the body to not absorb more iron and prevent further iron loading in the body. Iron loading in the body can cause excessive iron that contributes to life-threatening conditions such as heart and liver problems. Conversely, when hepcidin is suppressed in people with low levels of iron (iron deficiency), the absorption of iron through the intestine will be increased and replenish the iron in the body. This means that hepcidin level is influenced by the level of iron in the body. This explains the importance of hepcidin work to regulate absorption of iron.
Apart from being an iron regulator in people with low or high levels of iron in the body, it also works in people with low oxygen levels (hypoxia). Hepcidin in this condition which is low will release the stored iron from the liver cells (hepatocytes) and small intestines (enterocytes). This causes ferroportin to transport more iron to the bloodstream to make more haemoglobin and provide the hypoxic people more oxygen. Last but not least, the function of hepcidin is to recycle the iron macrophages. Macrophages are white blood cells that work by eliminating the old used red blood cells. The macrophages bind with iron from the haemoglobin of the old red blood cells and destroy it. After about four months, iron is recycled from the dying red blood cells by the, ready to be reused in the blood circulation system. It is worth noting that spleen and liver are also involved in recycling of iron.
Medical conditions affected by the hepcidin hormone does translate to the importance of hepcidin as the iron conservator. Low level of hepcidin is commonly associated with iron-deficiency anaemia since the body is unable to maintain the normal iron due to the inability of optimal iron absorption. High levels of hepcidin are associated with non-iron deficiency anaemia such as anaemia of chronic diseases such as infections and chronic kidney disease. Level of hepcidin may also be increased by inflammation in the body. In inflammation disease, the hepcidin level is not regulated solely by the iron status but is affected by the stimulation of a chemical known as cytokine. Cytokines are a substance released from immune reaction and affect cells. Hepcidin deficiency causes iron overload in hemochromatosis and anaemia with ineffective erythropoiesis (the way the body produces blood cells).
It can be concluded that hepcidin is an important hormone in the blood circulation system. Any changes to hepcidin level should be considered as telltale signs of an underlying medical condition. Hepcidin is often stimulated by excess iron. Blood test is typically the easiest way of knowing the level of hepcidin in the body. It is important to get regular medical checkups to ensure you are having a healthy life and if something is wrong, you can get early diagnosis and treatment.
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