Can chylomicrons formed in the intestine, with apolipoprotein B48, transport lipids to adipose cells for storage?


Fatty acids originating from chylomicron triacylglycerol are delivered mainly to adipose tissue, heart, and muscle (80%), while ~20% goes to the liver. - source: Harper's illustrated biochemistry.

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Lipoprotein lipase which is present in wall of blood capillaries anchored to endothelium by negatively charged proteoglycan chains of heparin sulfate requires phospholipids and apoC2 for its activity to take place.

Hydrolysis takes place while the lipoproteins are attached to the enzyme on the endothelium. Triacylglycerol is hydrolyzed progressively through a diacylglycerol to a monoacylglycerol and finally to FFA plus glycerol with the help of lipoprotein lipase. Some of the released free fatty acid return to general circulation bound to albumin but the bulk is transferred to peripheral tissues like adipose tissue, muscles of heart etc.

Fate of chylomicron
The lipase activity results in loss of 70%-90% of triacylglycerols and apoC2.(source: Harper's illustrated biochemistry) The remnant chylomicron is then taken up by liver by receptor mediated endocytosis. Here cholesteryl esters (present in concentrated form after loss of most of triacylglycerol) and remaining triacylglycerols are hydrolysed and metabolised.

  • $\begingroup$ Do you know what proportion of the fats in chilomicrons of dietary-origin get transported to what kind of tissue? I mean the parts that don't go to the liver - "adipose tissue, heart, and muscle (80%)". How much of that goes to adipocytes? $\endgroup$ – Abu Dhabi Aug 25 '18 at 8:42
  • $\begingroup$ @Abu Dhabi It depends on surface area of distribution (by blood vessels ), need for utilisation of fatty acid and many other factors. $\endgroup$ – Sikander Aug 25 '18 at 9:30

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