Protein synthesis

The liver is one of the most important organs for making proteins. It produces or transforms millions of protein molecules each day. Proteins are made from amino acids. Some of these amino acids are already in the body. Others, called the essential amino acids, can only be obtained from your diet. 

Proteins have many vital functions. We use them for the growth and maintenance of body tissues such as muscles, the heart, kidneys and blood vessel walls. The liver makes hundreds of different proteins with different functions. Some transport vitamins and minerals around the body. Some act as catalysts to speed up metabolic reactions (these proteins are called enzymes). Others regulate the pattern of all the different activities within a cell. 

Protein synthesis affected by HCV

Albumin

Albumin is usually present in high quantities in the blood. It is used to bind hormones, certain chemicals and drugs. Albumin also regulates the exchange of water between blood and tissues. If the concentration of water in the body fluids is not the same as that of the cells, there is a risk that fluid will burst out of the cells. 

During our lives the liver constantly monitors the body’s pressure level to ensure this is balanced. If the liver cannot synthesise enough albumin, a build-up of fluid in the tissues may occur. This is usually a symptom associated with decompensated cirrhosis where fluid may build up in the ankles, the feet or the legs (Oedema) or in the abdomen (Ascites).

Iron

The liver stores and releases iron around the body as and when it is needed. On its own, iron is toxic to the body’s cells so the body attaches it to a protein. In the liver iron is bound to the protein ferritin.

When liver disease is related to an increase in the amounts of ferritin in the liver it may cause damage to the tissues and organs. This is called haemochromatosis.

Iron is also essential for making haemoglobin. This helps to transport the oxygen in the bloodstream. If there is not enough iron to make haemoglobin this may lead to lethargy and anaemia.

Ammonia conversion

Ammonia is a toxic substance derived from the metabolism of proteins. The liver converts ammonia to urea, which is water-soluble, non-toxic and excreted by the kidneys. Liver dysfunction in decompensated cirrhosis can lead to an inability to convert this ammonia, which then builds up in the blood.