Gamma-GT

Gamma-glutamyltransferase (Gamma-GT or GGT) is an enzyme that plays a key role in the metabolism of glutathione, the most abundant antioxidant in the human body. GGT is involved in the transfer of amino acids and peptides across the cellular membrane and in the metabolism and detoxification of drugs and toxins. This enzyme is found in many tissues throughout the body, but is most concentrated in the liver, pancreas, and kidneys.

Function

Gamma-GT facilitates the breakdown of glutathione by cleaving the gamma-glutamyl functional group from its molecule. This action is crucial for the antioxidant's role in neutralizing reactive oxygen species and maintaining cellular health. Additionally, GGT plays a significant role in the amino acid transport mechanism, contributing to protein synthesis and cellular nutrition.

Clinical Significance

Elevated levels of GGT in the blood are often associated with liver diseases, such as hepatitis, cirrhosis, and liver cancer. It can also indicate bile duct obstruction and other conditions involving the liver or bile ducts. Because of its close association with liver function, GGT testing is commonly used in the diagnosis and monitoring of liver diseases.

GGT levels may also be elevated in response to excessive alcohol consumption, use of certain drugs (both prescription and recreational), and other medical conditions not directly related to the liver, such as pancreatitis and diabetes mellitus.

Diagnostic Use

The GGT test is a simple blood test that measures the level of gamma-glutamyltransferase in the blood. It is often part of a liver panel or comprehensive metabolic panel ordered for individuals showing symptoms of liver disease or for monitoring the liver function of patients on certain medications that can affect the liver.

Treatment and Management

Treatment for elevated GGT levels focuses on addressing the underlying condition. In cases where alcohol abuse or medication side effects are the cause, reducing alcohol consumption or adjusting the medication regimen may be recommended. For liver diseases, treatment may involve medication, lifestyle changes, or in severe cases, surgery.

See Also

• Liver function tests
• Hepatotoxicity
• Alcoholic liver disease
• Non-alcoholic fatty liver disease