The chylomicron may be thought of as a particle that has as its main function the transport of fat from the intestinal lumen to the liver. On the way to uptake by the liver, the chylomicron divests itself of lipid to the adipocyte for storage or the muscle and other cells for energy.
Their triglycerides are partially hydrolyzed during circulation as a result of the action of endothelial cell-bound lipoprotein lipase. The removal of triglycerides from chylomicrons in the peripheral tissues results in the formation of chylomicron remnants. The remnants are smaller particles that are mainly composed of cholesterol and are cleared primarily by the liver through a process mediated by apolipoprotein E and modulated by apolipoprotein C and phospholipids. The remnants are also linked to cardiovascular disease.
These particles consist of triglycerides (main constituent), phospholipids, cholesterol, proteins, apolipoproteins and fat-soluble vitamins. Apolipoproteins are the key protein constituents of chylomicrons. Although these proteins generally represent only less than 2% of the chylomicrons' total mass, they determine the intra- and extra-cellular metabolic fate of these lipoproteins.
Chylomicron major lipid is triglycerides, which comprise more than 75% of the particle, and they have the lowest protein content of all lipoproteins of around 2 percent.
Chylomicrons - Ultra low-density lipoproteins
