Transport of side-chain oxidized oxysterols in the human circulation

被引:114
作者
Babiker, A
Diczfalusy, U
机构
[1] Huddinge Univ Hosp, Karolinska Inst, Dept Med Lab Sci & Technol, Div Clin Chem, SE-14186 Huddinge, Sweden
[2] Huddinge Univ Hosp, Dept Surg, SE-14186 Huddinge, Sweden
来源
BIOCHIMICA ET BIOPHYSICA ACTA-LIPIDS AND LIPID METABOLISM | 1998年 / 1392卷 / 2-3期
关键词
24-hydroxycholesterol; 27-hydroxycholesterol; 3 beta-hydroxy-5-cholestenoic acid; lipoprotein fraction; distribution;
D O I
10.1016/S0005-2760(98)00047-2
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
To study the transport of 24-hydroxycholesterol, 27-hydroxycholesterol and 3 beta-hydroxy-5-cholestenoic acid in the circulation, the distribution of these oxysterols was determined in plasma, very low density lipoprotein, low density lipoprotein, high density lipoprotein, and lipoprotein-free plasma, An accurate method based on isotope dilution-mass spectrometry with use of individual deuterium labeled internal standards was used, 24-Hydroxycholesterol and 27-hydroxycholesterol were found to be associated mainly with HDL and LDL, whereas 3 beta-hydroxy-5-cholestenoic acid was found predominantly in the lipoprotein-free fraction. While both 24-hydroxycholesterol and 27-hydroxycholesterol are present mainly in esterified form in plasma, 3 beta-hydroxy-5-cholestenoic acid was present as free acid only. For reasons of comparison, a number of other oxysterols were determined in plasma and in isolated lipoprotein fractions, Significant amounts of these oxysterols were formed by cholesterol autoxidation during fractionation of plasma. It was therefore not possible to calculate the distribution of these oxysterols in the different plasma fractions. The present results are consistent with our previous finding that the less polar cholesterol metabolite 27-hydroxycholesterol competes with cholesterol for transport out of cells using HDL as an acceptor molecule, whereas the transport of the more polar compound 3 beta-hydroxy-5-cholestenoic acid is facilitated by albumin. (C) 1998 Elsevier Science B.V.
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页码:333 / 339
页数:7
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