Amylase, Urine

Amylase is an enzyme found primarily in the pancreas and salivary glands and in minor amounts in the liver and fallopian tubes. Whenever there is an inflammation of the pancreas or salivary glands, more amylase is released into the bloodstream and excreted by the kidneys. Amylase assists in the digestion of complex carbohydrates into simple sugars.
Amylase levels may be measured in the serum and in the urine. Whereas the serum amylase level begins to rise 3 to 6 hours after the onset of acute pancreatitis and returns to normal within 2 to 3 days after onset of acute pancreatitis, the urine amylase level is elevated for 7 to 10 days. Thus, testing for urine amylase is a useful way to demonstrate the presence of acute pancreatitis after serum amylase levels have returned to normal. The test may be conducted with a minimum of a 2-hour urine collection, a 24-hour urine collection, or a variety of other time periods.