Introduction to Chemistry of Lipids
2. Classification base on composition
2.9. High density lipoprotein (HDL)
High density lipoprotein (HDL) contains apoA-I, apoC-I, apoC-II and other apolipoproteins, as well as the enzyme lecithin-cholesterol acyl transferase (LCAT), which catalyzes the formation of cholesteryl esters from lecithin (phosphatidylcholine) and cholesterol.
• It facilitates the transport of fatty acids from
extrahepatic tissues to the liver
Biological significance
Cholesterol transport
- HDL carries cholesterol from peripheral tissues to the liver, where it's excreted from the body
- HDL delivers cholesterol to the adrenals, ovaries, and testes, which are important for steroid hormone synthesis
- HDL has anti-inflammatory properties in endothelial cells and leukocytes
- HDL reduces pro-inflammatory processes in vascular smooth muscle
- HDL is anti-thrombotic through actions on endothelium and platelets