Removal of triacylglycerols from chylomicrons and VLDL by capillary beds: the basis of lipoprotein remnant formation.
The triacylglycerol content of chylomicrons and VLDL (very-low-density lipoprotein) compete for the same lipolytic pathway in the capillary beds. Although chylomicron triacylglycerols appear to be the favoured substrate for lipoprotein lipase, VLDL particles compete in numbers. Methods to quantify the specific triacylglycerol removal from VLDL and chylomicrons may involve endogenous labelling of the triacylglycerol substrate with stable isotopes in combination with arteriovenous blood sampling in humans. Arteriovenous quantification of remnant lipoproteins suggests that adipose tissue with its high lipoprotein lipase activity is a principal site for generation of remnant lipoproteins. Under circumstances of reduced efficiency in the removal of triacylglycerols from lipoproteins, there is accumulation of remnant lipoproteins, which are potentially atherogenic.
Karpe
F
F
Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford OX3 7LJ, UK. Fredrik.Karpe@ocdem.ox.ac.uk
Bickerton
A S
AS
Hodson
L
L
Fielding
B A
BA
Tan
G D
GD
Frayn
K N
KN
D000273:Adipose Tissue / Q000098:blood supply / Q000378:metabolism; D002196:Capillaries / Q000378:metabolism*; D053298:Chylomicron Remnants / Q000097:blood / Q000378:metabolism; D002914:Chylomicrons / Q000378:metabolism*; D006801:Humans; D008071:Lipoprotein Lipase / Q000378:metabolism; D008079:Lipoproteins, VLDL / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000098:blood supply / Q000378:metabolism; D014018:Tissue Distribution; D014280:Triglycerides / Q000378:metabolism*
D053298:Chylomicron Remnants; D002914:Chylomicrons; D008079:Lipoproteins, VLDL; D014280:Triglycerides; D008071:Lipoprotein Lipase