ABSTRACT
The digestion of dietary fat which takes place in the small intestinal lumen is not complete, and the hydrolysis of the absorbed acylglycerols is continued to some extent in the enterocyte, where it also becomes subject to endogenous dilution and chyloportal partition. The intramucosal hydrolysis is brought about by specific intestinal hydrolases, which attack the short, medium, and long chain esters of glycerol at different rates. The highest rate of hydrolysis is obtained towards short or medium chain monoacylglycerols, whereas the long chain monoacylglycerols are poor substrates. The analysis of mucosa and lymph triacylglycerols of rats fed coconut oil, trilauroylglycerol, or 1,2-dilauroyl-3-oleoyl-sn-glycerol, pointed out that these lipids had undergone an extensive mucosal hydrolysis during their absorption. Glycerol monoester acylhydrolase activity has been demonstrated in vivo and in vitro in intestinal mucosa of several species of mammals. Lipids, chiefly free fatty acids and triacylglycerols are exudated to the lumen from the mucosa or blood through the intestinal wall.
