Chylomicron metabolism in rats: kinetic modeling indicates that the particles remain at endothelial sites for minutes
2013 (English)In: Journal of Lipid Research, ISSN 0022-2275, E-ISSN 1539-7262, Vol. 54, no 10, 2595-2605 p.Article in journal (Refereed) Published
Chylomicrons labeled in vivo with (14)C-oleic acid (primarily in triglycerides, providing a tracer for lipolysis) and (3)H-retinol (primarily in ester form, providing a tracer for the core lipids) were injected into rats. Radioactivity in tissues was followed at a series of times up to 40 min and the data were analyzed by compartmental modeling. For heart-like tissues it was necessary to allow the chylomicrons to enter into a compartment where lipolysis is rapid and then transfer to a second compartment where lipolysis is slower. The particles remained in these compartments for minutes and when they returned to blood they had reduced affinity for binding in the tissue. In contrast, the data for liver could readily be fitted with a single compartment for native and lipolyzed chylomicrons in blood, and there was no need for a pathway back to blood. A composite model was built from the individual tissue models. This whole-body model could simultaneously fit all data for both fed and fasted rats and allowed estimation of fluxes and residence times in the four compartments; native and lipolyzed chylomicrons ("remnants") in blood, and particles in the tissue compartments where lipolysis is rapid and slow, respectively.
Place, publisher, year, edition, pages
2013. Vol. 54, no 10, 2595-2605 p.
adipose tissue, chylomicron remnants, chylomicrons, compartmental modeling, endothelium, heart, lipolysis and fatty acid metabolism, lipoprotein kinetics, lipoprotein lipase, margination
Research subject Medical Biochemistry
IdentifiersURN: urn:nbn:se:umu:diva-82775DOI: 10.1194/jlr.M032979ISI: 000330534000003OAI: oai:DiVA.org:umu-82775DiVA: diva2:663121
FunderSwedish Research Council, 03X-00727