title: The tissue distribution of lipoprotein lipase determines where chylomicrons bind.
abstract: To determine the role of LPL for binding of lipoproteins to the vascular endothelium, and for the distribution of lipids from lipoproteins, four lines of induced mutant mice were used. Rat chylomicrons labeled in vivo with [(14)C]oleic acid (primarily in TGs, providing a tracer for lipolysis) and [(3)H]retinol (primarily in ester form, providing a tracer for the core lipids) were injected. TG label was cleared more rapidly than core label. There were no differences between the mouse lines in the rate at which core label was cleared. Two minutes after injection, about 5% of the core label, and hence chylomicron particles, were in the heart of WT mice. In mice that expressed LPL only in skeletal muscle, and had much reduced levels of LPL in the heart, binding of chylomicrons was reduced to 1%, whereas in mice that expressed LPL only in the heart, the binding was increased to over 10%. The same patterns of distribution were evident at 20 min when most of the label had been cleared. Thus, the amount of LPL expressed in muscle and heart governed both the binding of chylomicron particles and the assimilation of chylomicron lipids in the tissue.
authors.affiliation: Department of Medical Biosciences, Physiological Chemistry, Umeå University, Umeå, Sweden.
authors.forename: Roger
authors.initials: R
authors.lastname: Savonen
authors.affiliation: Institut für Medizinische Biochemie, Abteilung für Molekülarbiologie, Karl Franzens Universität, Graz, Austria.
authors.forename: Michaela
authors.initials: M
authors.lastname: Hiden
authors.affiliation: Department of Medical Biosciences, Physiological Chemistry, Umeå University, Umeå, Sweden.
authors.forename: Magnus
authors.initials: M
authors.lastname: Hultin
authors.affiliation: Institut für Medizinische Biochemie, Abteilung für Molekülarbiologie, Karl Franzens Universität, Graz, Austria.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Zechner
authors.affiliation: Department of Medical Biosciences, Physiological Chemistry, Umeå University, Umeå, Sweden.
authors.forename: Sanja
authors.initials: S
authors.lastname: Levak-Frank
authors.affiliation: Department of Medical Biosciences, Physiological Chemistry, Umeå University, Umeå, Sweden.
authors.forename: Gunilla
authors.initials: G
authors.lastname: Olivecrona
authors.affiliation: Department of Medical Biosciences, Physiological Chemistry, Umeå University, Umeå, Sweden. Electronic address: thomas.olivecrona@medbio.umu.se.
authors.forename: Thomas
authors.initials: T
authors.lastname: Olivecrona
mesh_terms: D000818:Animals; D002914:Chylomicrons / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008071:Lipoprotein Lipase / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D018482:Muscle, Skeletal / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D009928:Organ Specificity / Q000235:genetics; D051381:Rats
chemical_list: D002914:Chylomicrons; C548261:LPL protein, human; D008071:Lipoprotein Lipase
keywords: adipose tissue; heart; liver; muscle; nonesterified fatty acids; transgene; triglycerides