Aspartate aminotransferase (ASAT, AST, GOT)

Clinical significance

1) Physiologic changes in the catalytic concentration of AST in serum
AST is increased in normal newborns. The level found in adults is reached by the age of 7 years.

2) Pathologic changes in the catalytic concentration of AST in serum
A) Increased values of the catalytic concentration of AST in serum are found in::
a) Myocardial infarction
• acute rheumatic carditis– values depend on severity of a disease,
• after angiocardiography and cardiac catheterization,
• after closed cardiac massage,
• AST is inadequately specific to detect minor infarctions; in these cases, CK, LDH or HBDH should be determined,
• AST may also be increased in patients with acute cardiac congestive decompensation, arrhythmia or severe angina,
• AST values rise on the second postoperative day after cardiac surgery (7- to 8-fold normal values) and return to normal after 10 days,
• in myocardial infarction, AST may reach 4- to 10-fold reference values,
• serum AST values begin to rise after 3 h, reaching peak (4- to 10-fold) after 24 h and returning to normal values after 3-4 days.
b) Liver diseases
In liver diseases, AST values can be 10-100 times greater than normal.
• alcoholism,
• cholangitis
• leukemia
• lymphoma,
• infectious jaundice,
• infectious mononucleosis; peak reached in the second week of the disease, then returning to normal in the fifth week,
• liver infiltration (AST can be increased),
• carcinoma,
• liver lesion by carbon tetrachloride,
• pulmonary infarction;
AST shows a slower rise and reaches peak later than in myocardial infarction,
• therapy or intoxication with salicylates;
AST increase is proportional to the values of salicylate in plasma [salicylate concentration >1.81 mmol/L (25 mg/L)],
• therapy with rifampicin and isoniazide.
c) Pancreatic disease
• acute pancreatitis;
AST increase only in case of elevated serum bilirubin (biliary obstruction)
d) Trauma
• after direct current defibrillation,
• after intramuscular injection of ampicillin or carbenicillin,
• crush syndrome,
• hornet stings.
• intestinal infarction,
• intoxication with CO2 and CO (AST from muscle, heart and brain),
• local irradiation lesion,
• severe heat stroke,
e) Other diseases
• acute hemolytic anemia,
• acute renal disease,
• dermatomyositis,
• gout (acute phase),
• initial clofibrate therapy,
• myoglobinuria,
• progressive muscular dystrophy,
• severe burns.
• status asthmaticus,

B) Decreased values of the catalytic concentration of AST in serum are found in:
a) beriberi,
b) uncontrolled diabetes mellitus with acidosis.