- Last Update On : 2013-01-25
Lipases are a group of enzymes that hydrolyze the glycerol esters of long chain fatty acids. Serum lipase is mainly derived from the pancreatic acinar cells, where it is synthesized and stored in granules. Normally, more than 99% of stored enzyme is secreted into the pancreatic duct and less than 1% diffuses across cell membranes and reaches the circulation via lymphatics and capillaries. In acute pancreatitis, acinar cell membranes become more permeable, allowing much more enzyme to reach the circulation. In hemorrhagic pancreatitis, cellular necrosis leads to even more release of enzyme. Lipase is cleared from plasma by glomerular filtration and is subsequently almost totally reabsorbed and metabolized by the renal tubules. The circulating half-life of lipase is between 7 and 14 hours.
Serum lipase activity increases within 4 to 8 hours after the onset of acute pancreatitis, peaks at 24 hours and decreases within 8 to 14 days. Lipase levels usually increase from 7 to 11 ti