Abstract：
:The measurement of apolipoprotein B (apoB) in purified lipoproteins by immunological assays is subject to criticism because of denatured epitopes or immunoreactivity differences between purified lipoproteins and standard. Chemical methods have therefore been developed, such as the selective precipitation of apoB followed by quantification of the precipitate. In this study, we present the measurement of apoB concentration in lipoproteins purified by ultracentrifugation by combining isopropanol precipitation and gas chromatography/mass spectrometry. Very low density lipoprotein (VLDL; d < 1.006 g/mL); VLDL plus intermediate density lipoprotein (VLDL + IDL; d < 1.019 g/mL); and VLDL, IDL, and low density lipoprotein (VLDL + IDL + LDL; d < 1.063 g/mL) were purified by ultracentrifugation. Apolipoprotein B-100 was selectively precipitated by isopropanol. The leucine content of the pellet was then determined by gas chromatography/mass spectrometry, using norleucine as internal standard. Knowledge of the number of leucine molecules in one apoB-100 molecule makes it possible to calculate the plasma concentration of apoB in the various lipoprotein fractions. ApoB in IDL (d 1.006-1.019 g/mL) and LDL (d 1.019-1.063 g/mL) were then determined by subtracting VLDL-apoB from apoB in lipoproteins d < 1.019 and apoB in lipoproteins d < 1.019 g/mL from apoB in lipoproteins d < 1.063 g/mL, respectively. The isopropanol precipitate was verified as pure apoB (>97%) in lipoprotein fractions isolated from normo- and hyperlipidemic plasma and the method appeared reproducible. The combination of isopropanol precipitation and the GC/MS method appears therefore to be a precise and reliable method for kinetic and epidemiological studies.
journal_name
J Lipid Resjournal_title
Journal of lipid researchauthors
Beghin L,Duhal N,Poulain P,Hauw P,Lacroix B,Lecerf JM,Bonte JP,Fruchart JC,Luc Gkeywords:
subject
Has Abstractpub_date
2000-07-01 00:00:00pages
1172-6issue
7eissn
0022-2275issn
1539-7262journal_volume
41pub_type
杂志文章abstract：:This work describes the molecular mechanisms of fatty acid and hormonal modulations of the retinoid X receptor alpha (RXRalpha) in rat liver cells. We examined the effects of different fatty acids (myristic, stearic, oleic, linolenic, and arachidonic acids, EPA, and the peroxisomal proliferator TTA) and several hormon...
journal_title：Journal of lipid research
pub_type： 杂志文章
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更新日期：1998-04-01 00:00:00
abstract：:The bioactive sphingolipid metabolite, ceramide, regulates physiological processes important for inflammation and elevated levels of ceramide have been implicated in IL-1-mediated events. Although much has been learned about ceramide generation by activation of sphingomyelinases in response to IL-1, the contribution o...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M065920
更新日期：2016-08-01 00:00:00
abstract：:The transport of LDL-derived cholesterol from lysosomes to peroxisomes is facilitated by membrane contacts formed between the lysosomal protein synaptotagmin VII and the peroxisomal lipid phosphatidylinositol 4, 5-bisphosphate [PI(4,5)P2]. Here, we used RNA interference to search for regulators of PI(4,5)P2 and to stu...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M082149
更新日期：2018-03-01 00:00:00
abstract：:The inbred HcB19 mouse strain expresses a truncated form of thioredoxin interacting protein and is phenotypically characterized by fatty liver and elevated plasma triglycerides and VLDL. Recently, these mice have been proposed as an animal model for familial combined hyperlipidemia. The aim of the present study was id...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M400062-JLR200
更新日期：2004-06-01 00:00:00
abstract：:The sequences necessary for liver-specific expression of the apolipoprotein (apo) E gene have been shown to reside 3' to the gene, within the apoE/C-I/C-II gene cluster, but have not been precisely characterized. Utilizing a transient transfection reporter gene assay based on the apoC-II promoter, we have localized a ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1993-10-01 00:00:00
abstract：:The fatty acid transport protein (FATP) Fat1p in the yeast Saccharomyces cerevisiae functions in concert with acyl-coenzyme A synthetase (ACSL; either Faa1p or Faa4p) in vectorial acylation, which couples the transport of exogenous fatty acids with activation to CoA thioesters. To further define the role of Fat1p in t...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M700300-JLR200
更新日期：2007-11-01 00:00:00
abstract：:Scavenger receptor class B type I (SR-BI) has been identified as a functional HDL binding protein that can mediate the selective uptake of cholesteryl ester (CE) from HDL. To quantify the in vivo role of SR-BI in the process of selective uptake, HDL was labeled with cholesteryl ether ([(3)H] CEt-HDL) and (125)I-tyrami...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M400191-JLR200
更新日期：2004-11-01 00:00:00
abstract：:An enzyme (phosphatidyl glycerophosphate phosphatase) that catalyzes the formation of phosphatidyl glycerol from phosphatidyl glycerophosphate has been rendered soluble by treatment of the particulate fraction of E. coli with Triton X-100 in the presence of EDTA, and has been partially purified. The enzyme is specific...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1967-09-01 00:00:00
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journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1996-07-01 00:00:00
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journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/M900250-JLR200
更新日期：2010-01-01 00:00:00
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journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.D071068
更新日期：2016-11-01 00:00:00
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journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1989-05-01 00:00:00
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journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1976-01-01 00:00:00
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journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1999-12-01 00:00:00
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journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1982-05-01 00:00:00
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journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1966-05-01 00:00:00
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journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1997-11-01 00:00:00
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journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M800493-JLR200
更新日期：2009-10-01 00:00:00
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journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：2000-06-01 00:00:00
abstract：:The novel acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor CP-113,818 has been characterized in vitro against ACAT isolated from liver and intestine from a variety of species including human subjects, and in vivo in cholesterol-fed rats, hamsters, rabbits, and two species of nonhuman primates. CP-113,818 is a pot...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1994-10-01 00:00:00
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journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.D094516
更新日期：2019-08-01 00:00:00
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journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.m100404-jlr200
更新日期：2002-09-01 00:00:00
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journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1994-12-01 00:00:00
abstract：:A simple, rapid, and sensitive bioluminescence method for measuring primary bile acids has been developed and validated. The method is based on enzymatic dehydrogenation of bile acids using a bacterial 7 alpha-hydroxysteroid dehydrogenase that is co-immobilized on Sepharose 4B beads with NADH:FMN oxidoreductase and a ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1982-12-01 00:00:00
abstract：:Lipoprotein electrophoresis on agarose gel has been modified to allow estimation of the absolute quantity of each fraction. The reproducibility of the method is illustrated by 12 determinations in a single day on serum from one normal subject: mean total dye uptake was 302 +/- 9 (sd "corrected dye units," and the perc...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1971-07-01 00:00:00
abstract：:Cerebrotendinous xanthomatosis (CTX) is a rare, recessively inherited lipid storage disease characterized by a markedly reduced production of chenodeoxycholic acid and an increased formation of 25-hydroxylated bile alcohols and cholestanol. Patients with this disease are known to have mutations in the sterol 27-hydrox...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：2001-02-01 00:00:00
abstract：:We report on the effect of human apolipoprotein (apo) A-II transgene expression on atherosclerosis susceptibility in two transgenic lines (25.3 and 11.1) whose plasma human apoA-II concentrations (approximately 23 and 96 mg/dl, respectively) span the normal range in humans. After 9 months of an atherogenic diet, 25.3 ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1998-02-01 00:00:00
abstract：:The fatty acid composition of human skin fibroblasts grown in 10% dialyzed fetal calf serum can be modified considerably by adding supplemental fatty acids to the culture medium. The degree of modification was dependent on the concentration of added fatty acid over the range tested, 2.5 X 10(-5) to 1 X 10(-4) M. At th...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1979-05-01 00:00:00
abstract：:A higher incidence of coronary artery disease is associated with a lower level of HDL-cholesterol. We searched for genetic loci influencing HDL-cholesterol in F2 mice from a cross between MRL/MpJ and SM/J mice. Quantitative trait loci (QTL) mapping revealed one significant HDL QTL (Apoa2 locus), four suggestive QTL on...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M025833
更新日期：2012-06-01 00:00:00
abstract：:The surface area, A, of contracting fatty acid monolayers was measured as a function of time, t, at constant surface pressure. In the initial temporal phase, ln A was linear with radical t. In a subsequent steady-state phase, ln A was linear with t. The initial desorption coefficient for sodium palmitate, K(i), and th...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1973-01-01 00:00:00
