HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Spady, D. K. Articles by Dietschy, J. M. Search for Related Content PubMed PubMed Citation Articles by Spady, D. K. Articles by Dietschy, J. M. Social Bookmarking                      What's this?

Journal of Lipid Research, Vol 28, 32-41, Copyright © 1987 by Lipid Research, Inc.

ARTICLES

Role of receptor-independent low density lipoprotein transport in the maintenance of tissue cholesterol balance in the normal and WHHL rabbit

DK Spady, M Huettinger, DW Bilheimer and JM Dietschy

These studies were undertaken to determine the role of receptor- independent low density lipoprotein (LDL) transport in cholesterol balance across individual tissues and the whole animal. Homologous LDL, which measures total LDL transport, and methylated heterologous LDL, which measures receptor-independent LDL uptake, were cleared from the plasma at very different rates in the NZ control rabbit (3,900 and 1,010 microliter/hr per kg, respectively) whereas in the WHHL rabbit both preparations were cleared at essentially the same rate (approximately 1,070 microliter/hr per kg). Receptor-independent LDL clearance was detected in all tissues of the NZ control rabbit and these varied from 32 (spleen) to less than 0.5 (skeletal muscle) microliter/hr per g. In contrast, receptor-dependent LDL uptake was found in only about half of these same organs. In the WHHL rabbit, the rates of receptor-independent LDL transport were the same as in the NZ control rabbit, but no receptor-dependent uptake was detected. Using these clearance values it was calculated that in the control rabbit nearly 70% of LDL-cholesterol was removed from the plasma by the liver and 89% of this was receptor-mediated. With loss of receptor activity, however, the burden of LDL degradation was shifted away from the liver so that approximately 70% of LDL-cholesterol uptake took place in the extra-hepatic tissues of the WHHL rabbit. Thus, in the normal animal, the primary function of receptor-dependent LDL transport is to promote the rapid uptake and disposal of plasma LDL by the liver. In the absence of such receptor activity, cholesterol balance across most individual organs and the whole animal remains essentially normal and is mediated by the receptor-independent process. Because of the much lower absolute clearance rates manifested by this transport mechanism, however, substantial and predictable elevations in the circulating plasma LDL-cholesterol levels are required to maintain this balance.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				C. T. Chen, D. W. L. Ma, J. H. Kim, H. T. J. Mount, and R. P. Bazinet The low density lipoprotein receptor is not necessary for maintaining mouse brain polyunsaturated fatty acid concentrations J. Lipid Res., January 1, 2008; 49(1): 147 - 152. [Abstract] [Full Text] [PDF]

				B. Liu, C. Xie, J. A. Richardson, S. D. Turley, and J. M. Dietschy Receptor-mediated and bulk-phase endocytosis cause macrophage and cholesterol accumulation in Niemann-Pick C disease J. Lipid Res., August 1, 2007; 48(8): 1710 - 1723. [Abstract] [Full Text] [PDF]

				B. Zhao, Y. Li, C. Buono, S. W. Waldo, N. L. Jones, M. Mori, and H. S. Kruth Constitutive Receptor-independent Low Density Lipoprotein Uptake and Cholesterol Accumulation by Macrophages Differentiated from Human Monocytes with Macrophage-Colony-stimulating Factor (M-CSF) J. Biol. Chem., June 9, 2006; 281(23): 15757 - 15762. [Abstract] [Full Text] [PDF]

				C. Xie, L. A. Woollett, S. D. Turley, and J. M. Dietschy Fatty acids differentially regulate hepatic cholesteryl ester formation and incorporation into lipoproteins in the liver of the mouse J. Lipid Res., September 1, 2002; 43(9): 1508 - 1519. [Abstract] [Full Text] [PDF]

				C. Vasandani, A. I. Kafrouni, A. Caronna, Y. Bashmakov, M. Gotthardt, J. D. Horton, and D. K. Spady Upregulation of hepatic LDL transport by n-3 fatty acids in LDL receptor knockout mice J. Lipid Res., May 1, 2002; 43(5): 772 - 784. [Abstract] [Full Text] [PDF]

				C. Xie, S. D. Turley, and J. M. Dietschy Cholesterol accumulation in tissues of the Niemann-Pick type C mouse is determined by the rate of lipoprotein-cholesterol uptake through the coated-pit pathway in each organ PNAS, October 12, 1999; 96(21): 11992 - 11997. [Abstract] [Full Text] [PDF]

				D. K. Spady, J. A. Cuthbert, M. N. Willard, and R. S. Meidell Overexpression of Cholesterol 7alpha -Hydroxylase (CYP7A) in Mice Lacking the Low Density Lipoprotein (LDL) Receptor Gene. LDL TRANSPORT AND PLASMA LDL CONCENTRATIONS ARE REDUCED J. Biol. Chem., January 2, 1998; 273(1): 126 - 132. [Abstract] [Full Text] [PDF]

				M. Bertolotti, M. Concari, P. Loria, N. Abate, A. Pinetti, M. E. Guicciardi, and N. Carulli Effects of Different Phenotypes of Hyperlipoproteinemia and of Treatment With Fibric Acid Derivatives on the Rates of Cholesterol 7{alpha}-Hydroxylation in Humans Arterioscler. Thromb. Vasc. Biol., August 1, 1995; 15(8): 1064 - 1069. [Abstract] [Full Text]

				J. M. Dietschy and S. D. Turley Thematic review series: Brain Lipids. Cholesterol metabolism in the central nervous system during early development and in the mature animal J. Lipid Res., August 1, 2004; 45(8): 1375 - 1397. [Abstract] [Full Text] [PDF]