Chylomicron formation decreases the surface tension of Triacylglycerols and fatty acids thereby helping in its absorption into lacteals first and then into systemic circulation. Now, the chylomicrons consist of an amphipathic shell and a central core. This central core consists of TAG and fatty acid. On the periphery, Apolipoproteins are formed.
These apolipoproteins are Apo B-48 and Apo A. The next step in the chylomicron formation is the maturation of chylomicron. Mature chylomicron is formed after incorporating Apo C and Apo E which are donated by the HDL (High-Density Lipoprotein) towards the chylomicron.
Then this mature chylomicron enters the capillaries. In the capillaries, it encounters Lipoprotein Lipase enzyme which is present on the walls of capillary endothelium and activated BY Apo C-1 and Apo C
Lipoprotein Lipase acts on the Triacylglycerols which are present in the core of chylomicron, converting it into Fatty acid and glycerol. This fatty acid is taken up by the cell for various processes and this glycerol is diverted to act as a substrate in gluconeogenesis.H once, forming glucose. Now because of Triacylglycerols are depleting in the core, the size of the chylomicron reduces. Also, Apo C and Apo A return to HDL. Now, this chylomicron is said to be remnant chylomicron, having Apo B-48 and Apo -E. Apo E is recognized by the remnant receptors present on the Hepatic cell. Ultimately chylomicron is taken up by the liver and processes in it
One important point to note here is that HDL donates Apo- C and Apo E, but it gets Back in return APO A and Apo C.
To see complete chylomicron metabolism in a step-by-step manner click here