What Is Aspartate Aminotransferase?
Aspartate aminotransferase (AST) is found in various tissues of the human body, with the heart muscle being the most abundant, followed by liver. In the liver, the absolute value of aspartate aminotransferase (AST) exceeds that of glutamate aminotransferase (ALT). AST is divided into two isoenzymes based on their different locations in the cell, namely cytoplasmic aspartate aminotransferase (s-AST) and mitochondrial aspartate aminotransferase (m-AST). Because m-AST is localized in the mitochondria, it is not easy to release into the blood. When hepatocytes are necrotic, m-AST is released from mitochondria, which increases AST in serum. The measurement of isoenzyme is helpful to understand the degree of damage to myocardium, liver and kidney tissue.
Aspartate aminotransferase
- Chinese name
- Aspartate aminotransferase
- English name
- aspartate aminotransferase
- Meaning
- Understand the degree of damage to myocardial, liver, and kidney tissues
- Short name
- AST
- Specimen requirements
- Fasting venous blood collection to avoid hemolysis
- Aspartate aminotransferase (AST) is found in various tissues of the human body, with the heart muscle being the most abundant, followed by liver. In the liver, the absolute value of aspartate aminotransferase (AST) exceeds that of glutamate aminotransferase (ALT). AST is divided into two isoenzymes based on their different locations in the cell, namely cytoplasmic aspartate aminotransferase (s-AST) and mitochondrial aspartate aminotransferase (m-AST). Because m-AST is localized in the mitochondria, it is not easy to release into the blood. When hepatocytes are necrotic, m-AST is released from mitochondria, which increases AST in serum. The measurement of isoenzyme is helpful to understand the degree of damage to myocardium, liver and kidney tissue.
- Aspartate aminotransferase (AST) is mainly distributed in the heart muscle, followed by liver, skeletal muscle and kidney tissues. Under normal circumstances, the content of AST in serum is very low. When the relevant tissues and organs are damaged, the concentration of AST in serum will change accordingly. [1]
- The determination of serum aspartate aminotransferase is helpful to determine whether the heart and liver cells are necrotic and damaged. Increased AST: Common in acute and chronic severe hepatitis, cirrhosis, myocarditis, myocardial infarction, nephritis, cholangitis, dermatomyositis, and pancreatitis.
- Since the myocardium contains the highest AST content, followed by the liver, enzyme activity in blood can rapidly increase after heart and liver cell damage. However, simply measuring total AST activity cannot fully reflect the degree of heart and liver damage and determine the prognosis. Measurement of serum m-AST can indirectly understand the severity of liver cell ultrastructure damage and mitochondrial damage. m-AST can be used not only as an indicator of heart and liver cell necrosis, but also as an indicator of dynamic monitoring of heart and liver diseases.
- Male: 15 ~ 40U / L (continuous monitoring method)
- Female: 13 ~ 35U / L (continuous monitoring method) [1]