Transaminase enzymes are contained primarily in the liver and muscles, but also the kidneys and heart. Among the most common are distinguished the AST for aspartate transferase and ALT for alanine transferase. The blood levels of these enzymes are measured in blood tests. Transaminases may be temporarily elevated following a muscular effort. The levels of these two enzymes grow due to medications, but especially in liver damage and particularly in alcoholic or viral hepatitis. The trigger of this increase in blood levels comes from the destruction of liver cells, rich in transaminases. The AST, which is also contained in the cardiac muscle, is increased in the days following a myocardial infarction.