Lymphatic cholesterol amount

The fat-soluble vitamins share many properties despite their limited chemical similarity. They are absorbed into the intestinal lymphatics, along with other dietary lipids, after emulsification by bile salts. Lipid malabsorption accompanied by steatorrhea usually results in poor uptake of all the fat-soluble vitamins. Deficiency disease (except in the case of vitamin K) is difficult to produce in adults because large amounts of most fat-soluble vitamins are stored in the liver and in adipose tissue. The fat-soluble vitamins are assembled from isoprenoid units this fact is apparent from examination of the structures of vitamins A, E, and K cholesterol, the precursor of vitamin D, is derived from six isoprenoid units (Chapter 18). Specific biochemical functions for vitamins A, D, and K are known, but a role for vitamin E, other than as a relatively nonspecific antioxidant, remains elusive. 

Finally it is clear that, unlike long-chain fatty acids which can appear in portal blood in limited amounts[32], cholesterol is absorbed exclusively into the lymphatic circulation[32,33]. A small amount of unesterified cholesterol can appear in lymph and is largely associated with chylomicron and lipoprotein "coat , or limiting membrane. However, this coat has a limited capability for significant transport, and the mass transport cholesterol (like that of triglycerides) requires esterification and incorporation into the lipoprotein core. Thus, the transfer of significant amounts of cholesterol from intestinal lumen to l3onph is associated with extensive esterification (70-90%) with fatty acids, and this occurs in the mucosal epithelial cells[11]. There are two intestinal enzymes potentially important in the esterification of unesterified cholesterol cholesterol esterase, or sterol ester hydrolase (EC. 

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