AST: 1. Aspartate aminotransferase, an enzyme normally present in liver and heart cells. AST is released into blood when the liver or heart is damaged. The blood AST levels are thus elevated with liver damage (for example, from viral hepatitis) or with an insult to the heart (for example, from a heart attack). Some medications can also raise AST levels. AST is also known as serum glutamic oxaloacetic transaminase (SGOT). 2. Androgen suppression therapy. See: Androgen suppression.