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The enzyme that is more specific for liver disorders in AST/ALT testing is ALT, or alanine aminotransferase. This enzyme is predominantly found in the liver and is released into the bloodstream when liver cells are damaged. Elevated levels of ALT are typically interpreted as a sign of liver injury or disease, making it a key marker for hepatic conditions.

In contrast, AST, or aspartate aminotransferase, is present in various tissues throughout the body, including the liver, heart, and muscles. While it can also indicate liver damage, its presence in other tissues makes it less specific for liver disorders compared to ALT.

BUN (blood urea nitrogen) and alkaline phosphatase do not serve as reliable indicators of liver-specific issues in this context. BUN is generally a marker of kidney function, affected by protein metabolism or hydration status, while alkaline phosphatase can be elevated in a variety of conditions, not solely those related to the liver, such as bone disorders or biliary obstruction.

This specificity of ALT makes it the preferred enzyme when assessing liver health and diagnosing liver-related diseases.