Chylomicrons are rich in triglycerides and are derived from intestinal absorption of lipids. They are secreted from the intestinal mucosal cells into the intracellular fluid. Chylomicrons are responsible for transport of all dietary lipids into circulation.

The principal apoprotein component of chylomicron in apo-B-48, which is incorporated into the chylomicron in the intestine itself. This is the nascent chylomicron. In the circulation, apoproteins C and E are added. This results in the actual chylomicron. Apo-A is also present in chylomicron. The milky appearance (lactescence) of plasma seen after an average fatty meal is due to the presence of chylomicrons, which have the property of scattering light.

The lactescence clears after twelve to fourteen hours as the plasma passes through various organs, and this is due to the clearing action of enzyme lipoprotein lipase, located on the surface of endothelial cells of capillaries and also distributed in adipose tissue. The structure of the formation of chylomicrons and VLDL in the intestine and liver is shown in Figure 4.7.

Figure 4.7 Structure of the Formation of Chylomicrons and VLDL in the Intestine and Liver