Journal of Lipid Research, Vol 30, 1799-1810, Copyright © 1989 by Lipid Research, Inc.

ARTICLES

Utilization of cholesterol-rich lipoproteins by perfused rat adrenals

S Azhar, D Stewart and E Reaven
Department of Medicine, Stanford University School of Medicine, CA.

This study describes high density lipoprotein (HDL) uptake in the rat adrenal using a newly developed nonrecycling perfusion technique to control both the quality and quantity of the supplied lipoprotein. The aim of the study was to quantify a nonendocytic (alternative) pathway in the delivery of HDL-cholesterol. All experiments were conducted using an acute lipoprotein-deficient rat model (24 h 4-aminopyrazolo- [3, 4-d]-pyrimidine, 4-APP) in which circulating levels of cholesterol were reduced by one half, but various adrenal gland measurements of cholesterol metabolism were unchanged. Both rat HDL (rHDL) and affinity- purified human HDL3 (hHDL3) were used throughout the study. Microscopic autoradiographs (ARGs) indicate that both ligands bind avidly and exclusively to cells of the adrenal fasciculata and reticularis zones. Despite differences in binding affinity, both ligands deliver approximately the same total cholesterol to the cell interior as estimated by double-labeled residualizing tags on HDL (i.e., 125I- labeled dilactitol tyramine-[3H]cholesteryl linoleyl ether (DTT-CLE) HDL). The internalized cholesterol can account for much of the corticosterone produced during the 90-min time frame; however, only a small fraction of this cholesterol could have been provided via the endocytic pathway. Data obtained with the use of 125I-labeled DTT- [3H]CLE-HDL show that only 8.0% (or 0.7%) of corticosterone produced with rHDL (or hHDL3) could have come from cholesterol internalized as a component of intact HDL (i.e., via the endocytic pathway). These calculations strengthen the electron microscopy autoradiographic data that show that few exposed silver grains (representing the localization of the 125I-isotope) are found within the cell cytoplasm. Thus, despite differences in the uptake characteristics of the two ligands, most of the HDL-cholesterol internalized and used for corticosterone production during adrenal perfusion apparently comes from a pathway in which intact HDL are not internalized.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				F. B. Kraemer, W.-J. Shen, S. Patel, J.-i. Osuga, S. Ishibashi, and S. Azhar The LDL receptor is not necessary for acute adrenal steroidogenesis in mouse adrenocortical cells Am J Physiol Endocrinol Metab, February 1, 2007; 292(2): E408 - E412. [Abstract] [Full Text] [PDF]

				E. Reaven, Y. Cortez, S. Leers-Sucheta, A. Nomoto, and S. Azhar Dimerization of the scavenger receptor class B type I: formation, function, and localization in diverse cells and tissues J. Lipid Res., March 1, 2004; 45(3): 513 - 528. [Abstract] [Full Text] [PDF]

				F. B. Kraemer, W.-J. Shen, K. Harada, S. Patel, J.-i. Osuga, S. Ishibashi, and S. Azhar Hormone-Sensitive Lipase Is Required for High-Density Lipoprotein Cholesteryl Ester-Supported Adrenal Steroidogenesis Mol. Endocrinol., March 1, 2004; 18(3): 549 - 557. [Abstract] [Full Text] [PDF]

				L. Wang, M. A. Connelly, A. G. Ostermeyer, H.-h. Chen, D. L. Williams, and D. A. Brown Caveolin-1 does not affect SR-BI-mediated cholesterol efflux or selective uptake of cholesteryl ester in two cell lines J. Lipid Res., April 1, 2003; 44(4): 807 - 815. [Abstract] [Full Text] [PDF]

				R. E. Temel, J. S. Parks, and D. L. Williams Enhancement of Scavenger Receptor Class B Type I-mediated Selective Cholesteryl Ester Uptake from apoA-I-/- High Density Lipoprotein (HDL) by Apolipoprotein A-I Requires HDL Reorganization by Lecithin Cholesterol Acyltransferase J. Biol. Chem., February 7, 2003; 278(7): 4792 - 4799. [Abstract] [Full Text] [PDF]

				R. M. Rao, Y. Jo, S. Leers-Sucheta, H. S. Bose, W. L. Miller, S. Azhar, and D. M. Stocco Differential Regulation of Steroid Hormone Biosynthesis in R2C and MA-10 Leydig Tumor Cells: Role of SR-B1-Mediated Selective Cholesteryl Ester Transport Biol Reprod, January 1, 2003; 68(1): 114 - 121. [Abstract] [Full Text] [PDF]

				R. E. Temel, R. L. Walzem, C. L. Banka, and D. L. Williams Apolipoprotein A-I Is Necessary for the in Vivo Formation of High Density Lipoprotein Competent for Scavenger Receptor BI-mediated Cholesteryl Ester-selective Uptake J. Biol. Chem., July 12, 2002; 277(29): 26565 - 26572. [Abstract] [Full Text] [PDF]

				S. Azhar, A. Nomoto, and E. Reaven Hormonal regulation of adrenal microvillar channel formation J. Lipid Res., June 1, 2002; 43(6): 861 - 871. [Abstract] [Full Text] [PDF]

				E. Reaven, S. Leers-Sucheta, A. Nomoto, and S. Azhar Expression of scavenger receptor class B type 1 (SR-BI) promotes microvillar channel formation and selective cholesteryl ester transport in a heterologous reconstituted system PNAS, February 13, 2001; 98(4): 1613 - 1618. [Abstract] [Full Text] [PDF]

				E. Reaven, L. Zhan, A. Nomoto, S. Leers-Sucheta, and S. Azhar Expression and microvillar localization of scavenger receptor class B, type I (SR-BI) and selective cholesteryl ester uptake in Leydig cells from rat testis J. Lipid Res., March 1, 2000; 41(3): 343 - 356. [Abstract] [Full Text]

				S. Swarnakar, R. E. Temel, M. A. Connelly, S. Azhar, and D. L. Williams Scavenger Receptor Class B, Type I, Mediates Selective Uptake of Low Density Lipoprotein Cholesteryl Ester J. Biol. Chem., October 15, 1999; 274(42): 29733 - 29739. [Abstract] [Full Text] [PDF]

				G. Lambert, M. B. Chase, K. Dugi, A. Bensadoun, H. B. Brewer , Jr., and S. Santamarina-Fojo Hepatic lipase promotes the selective uptake of high density lipoprotein-cholesteryl esters via the scavenger receptor B1 J. Lipid Res., July 1, 1999; 40(7): 1294 - 1303. [Abstract] [Full Text]

				M. A. Connelly, S. M. Klein, S. Azhar, N. A. Abumrad, and D. L. Williams Comparison of Class B Scavenger Receptors, CD36 and Scavenger Receptor BI (SR-BI), Shows That Both Receptors Mediate High Density Lipoprotein-Cholesteryl Ester Selective Uptake but SR-BI Exhibits a Unique Enhancement of Cholesteryl Ester Uptake J. Biol. Chem., January 1, 1999; 274(1): 41 - 47. [Abstract] [Full Text] [PDF]

				X. Gu, B. Trigatti, S. Xu, S. Acton, J. Babitt, and M. Krieger The Efficient Cellular Uptake of High Density Lipoprotein Lipids via Scavenger Receptor Class B Type I Requires Not Only Receptor-mediated Surface Binding but Also Receptor-specific Lipid Transfer Mediated by Its Extracellular Domain J. Biol. Chem., October 9, 1998; 273(41): 26338 - 26348. [Abstract] [Full Text] [PDF]

				S. Azhar, A. Nomoto, S. Leers-Sucheta, and E. Reaven Simultaneous induction of an HDL receptor protein (SR-BI) and the selective uptake of HDL-cholesteryl esters in a physiologically relevant steroidogenic cell model J. Lipid Res., August 1, 1998; 39(8): 1616 - 1628. [Abstract] [Full Text]

				E. Reaven, A. Nomoto, S. Leers-Sucheta, R. Temel, D. L. Williams, and S. Azhar Expression and Microvillar Localization of Scavenger Receptor, Class B, Type I (a High Density Lipoprotein Receptor) in Luteinized and Hormone-Desensitized Rat Ovarian Models Endocrinology, June 1, 1998; 139(6): 2847 - 2856. [Abstract] [Full Text] [PDF]

				S. Swarnakar, M. E. Reyland, J. Deng, S. Azhar, and D. L. Williams Selective Uptake of Low Density Lipoprotein-Cholesteryl Ester Is Enhanced by Inducible Apolipoprotein E Expression in Cultured Mouse Adrenocortical Cells J. Biol. Chem., May 15, 1998; 273(20): 12140 - 12147. [Abstract] [Full Text] [PDF]

				S. Azhar, L. Tsai, S. Medicherla, Y. Chandrasekher, L. Giudice, and E. Reaven Human Granulosa Cells Use High Density Lipoprotein Cholesterol for Steroidogenesis J. Clin. Endocrinol. Metab., March 1, 1998; 83(3): 983 - 991. [Abstract] [Full Text]

				Z.-S. Ji, H. L. Dichek, R. D. Miranda, and R. W. Mahley Heparan Sulfate Proteoglycans Participate in Hepatic Lipaseand Apolipoprotein E-mediated Binding and Uptake of Plasma Lipoproteins, Including High Density Lipoproteins J. Biol. Chem., December 12, 1997; 272(50): 31285 - 31292. [Abstract] [Full Text] [PDF]

				R. E. Temel, B. Trigatti, R. B. DeMattos, S. Azhar, M. Krieger, and D. L. Williams Scavenger receptor class B, type I (SR-BI) is the major route for the delivery of high density lipoprotein cholesterol to the steroidogenic pathway in cultured mouse adrenocortical cells PNAS, December 9, 1997; 94(25): 13600 - 13605. [Abstract] [Full Text] [PDF]

				M. Komaromy, S. Azhar, and A. D. Cooper Chinese Hamster Ovary Cells Expressing a Cell Surface-anchored Form of Hepatic Lipase. CHARACTERIZATION OF LOW DENSITY LIPOPROTEIN AND CHYLOMICRON REMNANT UPTAKE AND SELECTIVE UPTAKE OF HIGH DENSITY LIPOPROTEIN-CHOLESTERYL ESTER J. Biol. Chem., July 12, 1996; 271(28): 16906 - 16914. [Abstract] [Full Text] [PDF]

				E. Reaven, L. Tsai, and S. Azhar Intracellular Events in the ``Selective'' Transport of Lipoprotein-derived Cholesteryl Esters J. Biol. Chem., July 5, 1996; 271(27): 16208 - 16217. [Abstract] [Full Text] [PDF]

				D. L. Williams, M. de la Llera-Moya, S. T. Thuahnai, S. Lund-Katz, M. A. Connelly, S. Azhar, G. M. Anantharamaiah, and M. C. Phillips Binding and Cross-linking Studies Show That Scavenger Receptor BI Interacts with Multiple Sites in Apolipoprotein A-I and Identify the Class A Amphipathic alpha -Helix as a Recognition Motif J. Biol. Chem., June 16, 2000; 275(25): 18897 - 18904. [Abstract] [Full Text] [PDF]

				S. Swarnakar, J. Beers, D. K. Strickland, S. Azhar, and D. L. Williams The Apolipoprotein E-dependent Low Density Lipoprotein Cholesteryl Ester Selective Uptake Pathway in Murine Adrenocortical Cells Involves Chondroitin Sulfate Proteoglycans and an alpha 2-Macroglobulin Receptor J. Biol. Chem., June 8, 2001; 276(24): 21121 - 21128. [Abstract] [Full Text] [PDF]