Intracellular
enzyme involved in amino acid and carbohydrate metabolism. Present in large
concentrations in liver, kidney; smaller amounts in skeletal muscle and
heart. Released with tissue damage.
Normal
Range: Laboratory-specific U/L
Increased
in: Acute viral hepatitis (ALT>AST), biliary tract obstruction (cholangitis,
choledocholithiasis), alcoholic hepatitis and cirrhosis (AST>ALT), liver
abscess, metastatic or primary liver cancer; right heart failure, ischemia
or hypoxia, injury to liver ("shock liver"), extensive trauma. Drugs causing
cholestasis and other hepatotoxic drugs.
Additional: ALT
screening of donor blood used in blood banks to exclude non-A, non-B hepatitis.
