The Lipolytic Enzymes of the Gastrointestinal Tract and Fat Digestion
In the chemical and physical form that dietary fat is consumed it is not available for uptake by the gastrointestinal tract. By enzymatic conversion and in the presence of bile salt, dietary fat is converted to a more hydrophilic form that allows efficient uptake in the proximal part of the small intestine. While it was previously thought that the lipase of pancreatic origin, the classical lipase, was responsible for the digestion of the main part of the dietary fat, it has become apparent in recent years that other enzymes are also of importance and that lipolysis in the gastro-intestinal tract results from the concerted effect of three lipases and a phospholipase. These are gastric lipase, classical pancreatic lipase, carboxyl ester lipase (also of pancreatic origin), and the phospholipase A2 secreted into the pancreatic juice. It has also been demonstrated that classical lipase action in duodenal contents is dependent on a protein co-factor named colipase.
KeywordsBile Salt Pancreatic Juice Pancreatic Lipase Lipolytic Enzyme Duodenal Content
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