GOT (AST, aspartate aminotransferase)

GOT – glutamate oxaloacetate transaminase, internationally AST (aspartate aminotransferase) – is an enzyme found in many tissues: especially abundant in liver cells, heart muscle and skeletal muscle, and in smaller amounts in the kidneys and red blood cells. Within the cell it sits both in the cytoplasm and in the mitochondria. GOT is measured in serum together with GPT, gamma-GT and other liver values; the blood sample is taken in a practice.

What GOT (AST) does in the body

GOT transfers an amino group from the amino acid aspartate to α-ketoglutarate, producing oxaloacetate and glutamate. This reaction links protein metabolism with energy metabolism: oxaloacetate is a building block of the citric acid cycle and a starting material for making new glucose in the liver. GOT is also part of the malate–aspartate shuttle, which cells use to move reducing equivalents from the cytoplasm into the mitochondria. As a helper substance the enzyme needs pyridoxal 5-phosphate, the active form of vitamin B6. Normally there is only a little GOT in the blood – it comes from ongoing cell turnover.

Low GOT – what happens in the body?

A low GOT value is generally unremarkable, as it means that only a few cells are releasing their enzyme into the blood. Because GOT needs vitamin B6 as a helper substance, measured values can be lower with a marked vitamin B6 deficiency – part of the enzyme is then inactive. Studies have also observed low values in people on dialysis and in people with low muscle mass. Beyond that, a low GOT value has no meaning of its own.

Raised GOT – what happens in the body?

When GOT rises in the blood, cells have been damaged or have become leakier and have released their enzyme. This can originate in the liver – for example with fatty liver or with liver inflammation caused by viruses, alcohol or certain medicines – but also in the muscles after intense exercise, injuries or muscle inflammation. Damage to the heart muscle also raises GOT. Because part of the enzyme sits in the mitochondria, it rises particularly with deeper cell damage. The ratio of GOT to GPT (De Ritis ratio) and muscle values such as creatine kinase help to assess which tissue the rise comes from. If red blood cells break down in the sample, the value can also come out higher.

The interpretation is given in your report.