Muscle Enzymes
The muscle enzymes panel groups enzymes that skeletal muscle releases into the blood. Creatine kinase (CK) comes mainly from skeletal muscle. Aspartate aminotransferase (AST) also comes from liver, heart, and other tissues, so it is not specific to muscle. The linked pages describe US population distributions, not clinical reference intervals.
Also listed under Metabolic .
Frequently Asked Questions
Why is AST in both the liver function and muscle enzymes panels?
AST is present in liver, skeletal muscle, heart muscle, and other tissues. It appears in each panel where it is commonly measured, and its population distribution includes all of those sources.
Are these clinical reference intervals?
No. They are survey-weighted percentiles for the US population, including people regardless of health status, and they carry no diagnostic meaning.