Alanine aminotransferase and Aspartate aminotransferase (ALT and AST)

Serum aminotransferases, primarily alanine aminotransferase (ALT) and aspartate aminotransferase (AST), are enzymes that catalyze the transfer of amino groups between amino acids and alpha-keto acids, playing a vital role in amino acid metabolism and gluconeogenesis (StatPearls, NBK459280). While ALT is predominantly found in the liver, making it a specific indicator of hepatocellular injury, AST is distributed across various tissues including the heart, skeletal muscle, and kidneys (NIH LiverTox, NBK547852). In clinical practice, these enzymes are not typically therapeutic targets but serve as critical biomarkers for diagnosing and monitoring liver diseases such as hepatitis, cirrhosis, and non-alcoholic fatty liver disease (PubMed, 22223177). Elevated serum levels usually indicate cellular damage or necrosis, leading to the leakage of these enzymes into the bloodstream (StatPearls, NBK470480). Consequently, they are standard components of liver function tests used to assess drug-induced liver injury (DILI) during clinical trials and routine medical care (FDA, Liver Toxicity Guidance). Although research-grade inhibitors like cycloserine exist, no clinical therapies currently target these enzymes for disease modification (UniProt, P24298).

Other names

Serum aminotransferasesTransaminasesSerum Glutamic Pyruvic Transaminase (SGPT)Serum Glutamic Oxaloacetic Transaminase (SGOT)Aminotransferases

Aminotransferases catalyze the reversible transfer of an alpha-amino group from an amino acid (such as alanine or aspartate) to an alpha-keto acid (such as alpha-ketoglutarate), a process that requires pyridoxal-5-phosphate (Vitamin B6) as an essential cofactor (StatPearls, NBK459280; UniProt, P24298).