Hepatocyte damage is a key process in the pathogenesis of various liver diseases. In clinical practice, serum contents of substances that are changed by hepatocyte damage are usually measured to assess liver function. These substances include alanine and aspartate transaminases, lactic dehydrogenase, globulin, and albumin. However, not all

the substances synthesized by hepatocytes are used to assess the development of liver damage. For example, little has been known about the possible involvement of alkaline phosphatase (AP) in the development of liver diseases, except as an important indicator of jaundice when elevated.