Amylase is a hydrolytic enzyme present in large amounts in the pancreas, within acinar cells, and salivary glands. It is present in smaller amounts in other tissues. It cleaves alpha-1,4-glucosidic bonds in glucose polymers such as starch and glycogen. It requires co-factors chloride and calcium ions. It is cleared by the kidney and hence, there is a small amount of amylase activity within urine.
Serum amylase is normally measured in the diagnosis of acute abdominal pain. Total levels are usually reported, although it is possible to distinguish P and S amylase from the pancreas and salivary glands respectively. As differentiation requires electrophoresis, this is not commonly warranted in the emergency situation where rapid, automated chromogenic assays are used.
Amylase assay on pleural or peritoneal fluid may be used to diagnose a pancreatic fistula.