ABSTRACT
This chapter outlines the major features of lipid absorption and highlights the multiple steps involved in the translocation of lipids from the lumen of the small intestine through the enterocyte into the lymphatic system. The digestion of neutral lipids is a very complex biochemical process occurring in the diverse mileu of the gastrointestinal tract. As a practical matter, the activity of preduodenal lipase is unimportant distal to the duodenum since pancreatic lipase is secreted with overwhelmingly more activity and the intestinal pH rises to neutrality where preduodenal lipase is inactive. The enzyme has its greatest activity in the villus tips of the proximal intestine suggesting a role in the metabolism of dietary lipids. Dietary lipids, being insoluble in water, require hydrolysis prior to absorption. Bile acid mixed micelles and vesicles enable the solubilized products to rapidly penetrate the intestinal mucosa.
