AST is glutathione, which is mainly found in the human heart muscle, followed by the liver, skeletal muscle and kidney. If the corresponding organ cells are damaged, the permeability of the cell membrane increases and the intracellular plasma glutathione is released into the blood, resulting in an increase in serum concentration in humans. It is commonly used clinically as an adjunctive test for acute myocardial infarction and myocarditis, and also in the diagnosis of liver disease. The normal value of glutathione is 0-40 U/L. When glutathione is significantly elevated and the ratio of glutathione to glutathione is greater than 1, it often indicates extensive damage within the liver parenchyma and a poor prognosis.