Gastric lipase, human, role

Orlistat (tetrahydrolipstatin) is a reversible inhibitor of oral, gastric, and pancreatic lipases. This inhibitor forms an ester linkage with serine (serine-152) in the active site of the lipase so that a decrease in the rate of lipid hydrolysis will occur [37]. Orlistat decreases the oral taste sensitivity to both oleic acid and triolein in obese subjects [38]. These results further suggest a role for lingual lipase in oral fat hydrolysis and detection. However, a conclusive role for human lingual lipase in oral fatty acid hydrolysis and detection still remains imclear at the present time [39]. 

Dietary retinyl esters, retinol, and provitamin A carotenoids are dispersed and emulsified in the stomach during the gastric phase of lipid digestion. They then enter the lumen of the duodenum where extensive hydrolysis of retinyl esters takes place. In infants, the bile salt-stimulated lipase in human milk may play a role in retinyl ester hydrolysis in the duodenum (Fredrikzon et al., 1978). The major retinyl ester hydrolase activity that acts in the intestines is, however, derived from the pancreas. 

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