What is AST in blood test? | Aspartate Aminotransferase

Aspartate aminotransferase or AST is a routine test we can use anytime to screen for liver problems. Your doctor may order an AST measure if you have symptoms such as jaundice, abdominal pain, or had a recent encounter with a patient with hepatitis. But even if you don’t have any of these problems and feel fine, you will likely get measure at some point.

But what is aspartate aminotransferase? Why does your doctor order the exam? What can you do if you have an abnormal level? We’ll cover all of these questions in the following article.

What is Aspartate Aminotransferase (AST)?

Aspartate aminotransferase is also known as AST, but you can find it as SGOT, short for serum glutamic-oxalacetic transaminase. It is a sensitive marker of liver injury, and it is a soluble enzyme found in hepatocytes. It shouldn’t be in the blood at high levels in normal circumstances, but when hepatocytes break, they start to leak AST to the circulation.

Even if you don’t have a considerable injury, you may still have some AST in your blood. This is sometimes due to microscopic injuries that are immediately fixed. Yet, in other cases, there’s no way to trace the exact origin of this minimal amount of AST in normal blood samples.

AST can be found in different tissues besides hepatocytes, especially in cardiac muscle and skeletal muscle. So, the same elevation happens when these tissues are damaged as in muscle exertion, myocardial infarction, and muscular dystrophies.

Normal levels of AST are usually in the range of 35 to 40 units per liter of serum. However, this measure might depend on each laboratory.