Aspartate aminotransferase (AST)
|See Also||Lab Tests|
Aspartate aminotransferase, also known as AST or SGOT, is the enzyme that catalyzes the conversion of the amino acid L-asparate and α-keto-glutarate into oxaloacetate and L-glutamate., hence the older name SGOT or serum glutamate-oxalocetate tranferase. This test is often used to evaluate coronary artery occlusive disease or suspected hepatocellular diseases., 
- AST is an enzyme found in cells throughout the body, but mostly in the heart and liver, and to a lesser extent in the kidneys and muscles. AST levels increase when liver cells and/or heart muscle cells and/or skeletal muscle cells are damaged.
- AST is functionally similar to ALT yet it levels do not increase as much in response to liver dysfunction.
- AST is more specific for the detection of cardiovascular disease.
- AST levels in the blood typically increase within 12 hours of cellular damage and remain elevated for about 5 days.
Fasting is not required for this test.
- Factors which can cause increased levels:
- Drugs: antihypertensives, cholinergic agents, coumarin-type anticoagulants, digitalis preparations, erythromycin, isoniazid, methyldopa, oral contraceptives, opiates, salicylates, hepatotoxic medications, and verapamil.
- Factors which can cause decreased levels:
Ranges:' The following are the reference ranges for this lab. However, lab ranges can vary by laboratory and country. 
|Standard U.S. Units (U/L)||Standard International Units (U/L)|
|Conventional Laboratory Range||0 - 40||0 - 40|
|Optimal Range||10 - 30||10 - 30|
|Alarm Ranges||> 100||> 100|
High levels indicate:
- Liver Diseases
- Skeletal Muscle Disease
- Skeletal muscle trauma, such as extreme exercise or weight training
- Recent surgery
- Multiple traumas
- Severe, deep burns
- Progressive muscular dystrophy
- Recent convulsions
- Heat stroke
- Primary muscle diseases, such as myopathy or myositis
- Other Diseases
Low levels indicate
- Acute renal disease
- Vitamin B6 deficiency
- Protein deficiency
- Diabetic ketoacidosis
- Chronic renal dialysis
- Creatine Kinase (CK), ALT, Lactate Dehydrogenase, Leucine Aminopeptidase, Gamma-Glutamyl Transpeptidase, Alkaline Phosphatase, Bilirubin, Liver Function Tests, Albumin, Total Protein
- Pagana Kathleen D, Pagana Timothy J (2006) Mosby's Manual of Diagnostic and Laboratory Tests, Mosby.
- Weatherby Dicken, Ferguson Scott (2002) Blood Chemistry and CBC Analysis: Clinical Laboratory Testing from a Functional Perspective, Bear Mountain.