What enzyme is liver specific?

Alanine transaminase (ALT) is considered liver specific because it catalyzes the conversion of alanine to pyruvate while transferring the amino group from alanine to α-ketoglutarate, forming glutamate. Elevated levels of ALT are most closely associated with liver damage or hepatic disorders, making it a critical marker for liver health.

While alkaline phosphatase, lactate dehydrogenase, and aspartate transaminase can be found in multiple tissues—including bone, heart, muscle, and other organs—the presence and significant elevation of ALT typically indicate hepatocellular injury. This specificity is vital for diagnostic purposes, particularly in differentiating liver diseases such as hepatitis or cirrhosis from other conditions. In clinical practice, measuring ALT levels provides valuable information regarding liver function and guides further investigation into liver health.