Glutathione aminotransferase, also known as aspartate aminotransferase (AST), is a non-specific intracellular functional enzyme found mainly in cardiac muscle and, to a lesser extent, in liver, skeletal muscle and kidney tissues. When normal, serum levels are very low, when cell injury, the release of the enzyme in the cytoplasm into the blood, can make the enzyme activity in the serum increased. If AST is elevated, the damage is more serious, and it is commonly seen in the following diseases: 1. heart disease: the AST content in cardiomyocytes is higher, and if the heart is damaged, the AST is elevated in the patient’s examination. 1. heart failure: when the patient is in heart failure, the cardiac output is insufficient, and the patient can have elevated AST. 2. myocardial infarction: the AST can be elevated 6-8 hours after acute infarction The degree of AST elevation is related to the extent and degree of myocardial necrosis. If the AST increases again, it indicates that the scope of myocardial infarction is expanding or a new infarction has occurred; 3, myocarditis: due to viral infections, drug factors and other factors leading to myocarditis, the patient’s myocardium is damaged and the examination can show an increase in AST. Second, hepatobiliary diseases: 1, viral hepatitis: acute viral hepatitis or acute severe hepatitis at the beginning of the course of AST can be significantly higher, if the recovery period of acute hepatitis AST activity is not reduced to normal or still in the rise of symptoms can indicate the transformation to chronic hepatitis; 2, cirrhosis: cirrhosis patients with severe damage to liver cells, patients can appear AST elevated, but patients with end-stage cirrhosis can appear AST turned to normal phenomenon 3, non-viral liver disease: mostly seen in alcoholic, drug-related liver injury, as well as fatty liver, liver cancer, etc., AST can be mildly elevated; 4, cholestasis: cholestasis occurs in the liver and outside, AST activity can appear mildly elevated. Others: AST can be elevated in skeletal muscle lesions such as dermatomyositis and progressive myasthenia, as well as in kidney injury.