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Serum asparagine aminotransferase

Anatori Sealife Comments 0 11th April 2019
Serum asparagine aminotransferase enzyme allows establishing extend of damage caused tissues of the liver, heart and skeletal muscles.

Serum asparagine aminotransferase enzyme is suitable to determine the extent of damage caused by liver, heart and skeletal muscle tissues. There is an increase in activity in myocardial infarction. Besides, an increase in enzyme activity becomes noticeable at the 4th – 6th hours of a heart attack. The increased activity persists for the next 3-5 days, which is acute rheumatic carditis.

Effect of serum asparagine aminotransferase

It helps in cardiac surgeries, angiocardiography (catheterization of heart vessels), clotting of pulmonary arteria, severe attacks of stenocardia, tachyarrhythmia, viral hepatitis, toxic damage of liver. Four-chloride carboneum, chloroform, pesticides. Hepatic cirrhosis, amoeboid infections, cholangitis, infectious mononucleosis, acute alcoholic poisoning, hemocatheretic syndrome, muscular dystrophies, acute pancreatitis.

It catalyzes a reversible amino group transfer reaction from aspartic acid to α-ketoglutaric acid. It simultaneously forms oxaloacetic and glutamic acids. Transamination occurs in the presence of a coenzyme – pyridoxal phosphate, a vitamin B6 derivative. The tissue of the heart, liver, skeletal muscle, nerve tissue and kidney, to a lesser extent, the pancreas, spleen and lungs contain ACT.


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Mitochondrial and cytoplasmic isoenzymes

Two isoenzymes represent the ACT in cells – mitochondrial and cytoplasmic. About 1/3 of the total intracellular activity of ACT is in the cytoplasm of cells, and 2/3 are in mitochondria. In the myocardium, ACT activity is about 10,000 times higher than in the serum of healthy people. Increased ACT activity in myocardial infarction is one of the early markers of heart muscle damage, although its specificity is low. Also, the serum ACT level rises 6-8 hours after the onset of the pain attack; the peak falls at 18-24 hours, the activity decreases to typical values ​​on the 4-5th day. There is a relationship between the size of necrosis’ focus in the heart muscle and the serum ACT level.

An increase in ACT activity

An increase in ACT activity by a factor of 4–5 in an older adult, as a rule, indicates an acute myocardial infarction. Further, a rise of 10–15 times is an unfavourable prognostic sign. At the same time, a less pronounced increase in serum ACT levels does not necessarily indicate a favourable prognosis. The increasing activity of the enzyme in dynamics may indicate the expansion of the heart attack. It may also indicate the involvement of other organs and tissues in the pathological process. We can consider the liver as an example in this case. With myocardial infarction, ALT activity increases slightly, so the de Ritis coefficient (AST / ALT ratio) increases sharply.