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

This Article Full Text 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 Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Meaney, S. Articles by Björkhem, I. Search for Related Content PubMed PubMed Citation Articles by Meaney, S. Articles by Björkhem, I. Social Bookmarking                      What's this?

Journal of Lipid Research, Vol. 42, 70-78, January 2001
Copyright © 2001 by Lipid Research, Inc.

Original Article

Evidence that the major oxysterols in human circulation originate from distinct pools of cholesterol: a stable isotope study

Correspondence to: Ingemar Björkhem, To whom correspondence should be addressed.

The major oxysterols in human circulation are 7-, 27-, and (24S)-hydroxycholesterol. Two unique experiments were performed to elucidate their origin and kinetics. A volunteer was exposed to ¹⁸O₂-enriched air. A rapid incorporation of ¹⁸O in both 7- and 27-hydroxycholesterol and disappearance of label after exposure were observed. The half-life was estimated to be less than 1 h. Incorporation of ¹⁸O in (24S)-hydroxycholesterol was not significant. In the second experiment a volunteer was infused with liposomes containing 10 g of [²H₆]cholesterol. This resulted in an enrichment of plasma cholesterol with ²H of up to 13%, and less than 0.5% in cerebrospinal fluid cholesterol. The content of ²H in circulating 7-hydroxycholesterol remained approximately equal to that of plasma cholesterol and decreased with a half-life of about 13 days. The ²H content of circulating 27-hydroxycholesterol was initially lower than that of cholesterol but in the last phase of the experiment it exceeded that of cholesterol. No significant incorporation of ²H in (24S)-hydroxycholesterol was observed.

It is evident that 7-hydroxycholesterol must originate from a rapidly miscible pool, about 80% of 27-hydroxycholesterol from a more slowly exchangeable pool, and more than 90% of (24S)-hydroxycholesterol from a nonexchangeable pool, presumably the brain. The results are discussed in relation to the role of oxysterols in cholesterol homeostasis and their use as markers for pathological conditions. — Meaney, S., M. Hassan, A. Sakinis, D. Lütjohann, K. von Bergmann, Å. Wennmalm, U. Diczfalusy, and I. Björkhem. Evidence that the major oxysterols in human circulation originate from distinct pools of cholesterol: a stable isotope study. J. Lipid Res. 2001. 42: 70;–78.

Supplementary key words: CYP7A, CYP27, CYP46, brain choles-terol, ¹⁸O study

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				V. Hirsch-Reinshagen, J. Y. Chan, A. Wilkinson, T. Tanaka, J. Fan, G. Ou, L. F. Maia, R. R. Singaraja, M. R. Hayden, and C. L. Wellington Physiologically regulated transgenic ABCA1 does not reduce amyloid burden or amyloid-{beta} peptide levels in vivo J. Lipid Res., April 1, 2007; 48(4): 914 - 923. [Abstract] [Full Text] [PDF]

				I. Bjorkhem and S. Meaney Brain Cholesterol: Long Secret Life Behind a Barrier Arterioscler. Thromb. Vasc. Biol., May 1, 2004; 24(5): 806 - 815. [Abstract] [Full Text]

				I. Burkard, K. M. Rentsch, and A. von Eckardstein Determination of 24S- and 27-hydroxycholesterol in plasma by high-performance liquid chromatography-mass spectrometry J. Lipid Res., April 1, 2004; 45(4): 776 - 781. [Abstract] [Full Text] [PDF]

				V. Leoni, T. Masterman, P. Patel, S. Meaney, U. Diczfalusy, and I. Bjorkhem Side chain oxidized oxysterols in cerebrospinal fluid and the integrity of blood-brain and blood-cerebrospinal fluid barriers J. Lipid Res., April 1, 2003; 44(4): 793 - 799. [Abstract] [Full Text] [PDF]

				S. Meaney, K. Bodin, U. Diczfalusy, and I. Bjorkhem On the rate of translocation in vitro and kinetics in vivo of the major oxysterols in human circulation: critical importance of the position of the oxygen function J. Lipid Res., December 1, 2002; 43(12): 2130 - 2135. [Abstract] [Full Text] [PDF]

				K. Meir, D. Kitsberg, I. Alkalay, F. Szafer, H. Rosen, S. Shpitzen, L. B. Avi, B. Staels, C. Fievet, V. Meiner, et al. Human Sterol 27-Hydroxylase (CYP27) Overexpressor Transgenic Mouse Model. EVIDENCE AGAINST 27-HYDROXYCHOLESTEROL AS A CRITICAL REGULATOR OF CHOLESTEROL HOMEOSTASIS J. Biol. Chem., September 6, 2002; 277(37): 34036 - 34041. [Abstract] [Full Text] [PDF]

				K. Bodin, U. Andersson, E. Rystedt, E. Ellis, M. Norlin, I. Pikuleva, G. Eggertsen, I. Bjorkhem, and U. Diczfalusy Metabolism of 4beta -Hydroxycholesterol in Humans J. Biol. Chem., August 23, 2002; 277(35): 31534 - 31540. [Abstract] [Full Text] [PDF]

				C. Root, C. D. Smith, S. S. Sundseth, H. M. Pink, J. G. Wilson, and M. C. Lewis Ileal bile acid transporter inhibition, CYP7A1 induction, and antilipemic action of 264W94 J. Lipid Res., August 1, 2002; 43(8): 1320 - 1330. [Abstract] [Full Text] [PDF]

				D. Lutjohann, A. Brzezinka, E. Barth, D. Abramowski, M. Staufenbiel, K. von Bergmann, K. Beyreuther, G. Multhaup, and T. A. Bayer Profile of cholesterol-related sterols in aged amyloid precursor protein transgenic mouse brain J. Lipid Res., July 1, 2002; 43(7): 1078 - 1085. [Abstract] [Full Text] [PDF]

				S. Locatelli, D. Lutjohann, H. H.-J. Schmidt, C. Otto, U. Beisiegel, and K. von Bergmann Reduction of Plasma 24S-Hydroxycholesterol (Cerebrosterol) Levels Using High-Dosage Simvastatin in Patients With Hypercholesterolemia: Evidence That Simvastatin Affects Cholesterol Metabolism in the Human Brain Arch Neurol, February 1, 2002; 59(2): 213 - 216. [Abstract] [Full Text] [PDF]

				I. Bjorkhem, U. Andersson, E. Ellis, G. Alvelius, L. Ellegard, U. Diczfalusy, J. Sjovall, and C. Einarsson From Brain to Bile. EVIDENCE THAT CONJUGATION AND omega -HYDROXYLATION ARE IMPORTANT FOR ELIMINATION OF 24S-HYDROXYCHOLESTEROL (CEREBROSTEROL) IN HUMANS J. Biol. Chem., September 28, 2001; 276(40): 37004 - 37010. [Abstract] [Full Text] [PDF]