Abstract:
:We have developed the technique of rapid (< 2 h) centrifugal ultrafiltration to measure the inter-mixed micellar/vesicular (non-lecithin-associated) bile salt (BS) concentrations (IMC) of individual BS in model biles. This methodology uses a centrifugal concentrator with a reinforced membrane, through which a small fraction (< 15% total volume) of model biles was ultrafiltered by low centrifugal forces (1500 g 5-60 min). Total and individual BS concentrations in the filtrate were measured by high performance liquid chromatography. However, non-filterable anions, in this case BS/lecithin/cholesterol mixed micelles and unilamellar vesicles, induce an asymmetric distribution of ions across the membrane. Therefore, BS concentrations in the filtrate exceeded the true IMC, which was estimated taking into account Donnan equilibrium effects. To confirm the hypothesis that a correction for Donnan forces was necessary, distributions of BS and another filterable anion, chloride, were measured in systems containing the non-filterable polyanion dextran sulfate as an analogue for non-filterable polyanionic mixed micelles and vesicles. An asymmetric distribution of the monovalent anions chloride and BS monomers as well as polyvalent simple BS micelles was indeed present during centrifugal ultrafiltration. This new methodology was validated by comparing IMC values with those obtained by modified equilibrium dialysis also corrected for Donnan equilibrium effects (Donovan, J.M., et al. 1991. J. Lipid Res. 32: 1501-1512). Centrifugal ultrafiltration, which utilizes < 1 ml of bile, determines the composition in the IMC necessary to separate micelles and vesicles of native biles by techniques that involve dilution of bile such as gel filtration chromatography.
journal_name
J Lipid Resjournal_title
Journal of lipid researchauthors
Donovan JM,Jackson AAsubject
Has Abstractpub_date
1993-07-01 00:00:00pages
1121-9issue
7eissn
0022-2275issn
1539-7262journal_volume
34pub_type
杂志文章abstract::Previous studies have indicated that a G to A substitution at position -76 in the gene encoding apolipoprotein A-I (apoA-I) confers increased plasma high density lipoprotein cholesterol (HDL-C). Increased HDL-C may be a direct consequence of the A allele, or may reflect the action of a locus in linkage disequilibrium ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1994-07-01 00:00:00
abstract::Two novel mutations of the low density lipoprotein (LDL)-receptor gene were found in two Italian familial hypercholesterolemia (FH)-heterozygotes. The first mutation was an 18 nucleotide duplication in exon 8 which is preceded by an A-->T transversion. The translation product of the mutant allele was predicted to be a...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1998-07-01 00:00:00
abstract::In studies of cebus monkey plasma lipoproteins, we have used an ultracentrifugally generated density gradient to isolate two distinct species of low density lipoproteins (LDL). Compositional analyses revealed that each of the ultracentrifugally isolated fractions was enriched in cholesteryl esters and contained a sing...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1989-05-01 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::Steroid balance studies were conducted on 24 conventional and 12 germfree male rats, 90-120 days old, fed diets containing either 20% safflower or 20% coconut oil. Both germfree and conventional rats fed the safflower oil diets had significantly lower serum cholesterol levels and significantly higher liver cholesterol...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1974-11-01 00:00:00
abstract::This study sought to clarify the contributions of organic anion-transporting polypeptide (OATP) 1B1 and 1B3 to the liver uptake of chenodeoxycholic acid (CDCA). We synthesized a fluorescent version of CDCA, chenodeoxychilyl-(Nepsilon-NBD)-lysine (CDCA-NBD), to characterize transporter-mediated uptake. CDCA-NBD is effi...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M500532-JLR200
更新日期:2006-06-01 00:00:00
abstract::3alpha-Hydroxy-5-cholanoic acid (lithocholic acid) and some unidentified acids (one of them perhaps 3-hydroxy-cholest-5-en-26-oic acid) have been detected in the brains of guinea pigs afflicted with experimental "allergic" encephalomyelitis. None of the acids could be identified in comparable amounts of brain tissue f...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1969-01-01 00:00:00
abstract::Two assays for the quantitative measurement of HMG-CoA reductase, the major regulatory enzyme in hepatic cholesterol biosynthesis, are described. The first of these procedures employs thin-layer chromatography (TLC) of the reaction product on plastic-backed silica gel G strips impregnated with ammonium carbonate. The ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1977-05-01 00:00:00
abstract::The apolipoprotein (apo) B-100-specific monoclonal antibody MB47 has been widely used in lipoprotein metabolism and atherosclerosis research. When bound to apoB-100 on low density lipoproteins (LDL), antibody MB47 completely blocks the binding of LDL to the LDL receptor. The epitope for antibody MB47 has previously be...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1994-03-01 00:00:00
abstract::Despite a complete lack of microsomal triglyceride transfer protein (MTP), L35 rat hepatoma cells secrete triglyceride-containing lipoproteins, albeit at a rate 25% of that of parental FAO hepatoma cells, which express high levels of MTP. The inability to express MTP was associated with a complete block in the secreti...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:2002-05-01 00:00:00
abstract::Endothelial lipase (EL) has been shown to be a critical determinant for high density lipoprotein cholesterol levels in vivo; therefore, assays that measure EL activity have become important for the discovery of small molecule inhibitors that specifically target EL. Here, we describe fluorescent Bodipy-labeled substrat...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.D600041-JLR200
更新日期:2007-02-01 00:00:00
abstract::Sphingolipids are ubiquitous components of eukaryotic cells that regulate various cellular functions. In many cell types, a fraction of sphingolipids contain 2-hydroxy fatty acids, produced by fatty acid 2-hydroxylase (FA2H), as the N-acyl chain of ceramide [hydroxyl fatty acid (hFA)-sphingolipids]. FA2H is highly exp...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M800666-JLR200
更新日期:2009-06-01 00:00:00
abstract::Quantitative aspects of the binding of free fatty acid to human erythrocytes were studied by measuring the distribution of various amounts of [1-(14)C]lauric acid between washed human erythrocytes and defatted human plasma albumin. Incubations were done at 37 degrees C in an isotonic phosphate-buffered salt solution. ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1972-07-01 00:00:00
abstract::A simple procedure is described for preparing lyso-GM1, a GM1 derivative that lacks the fatty acid moiety, starting from GM1 ganglioside using a one-pot reaction. Ganglioside deacylation was carried out in KOH/propan-1-ol in the absence of oxygen. The yield of lyso-GM1 under optimal conditions (6 h, 90 degrees C, 0.2 ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1992-08-01 00:00:00
abstract::The LDL receptor-related protein-1 (LRP1) is highly expressed in numerous cell types, and its impairment is associated with obesity, diabetes, and fatty liver disease. However, the mechanisms linking LRP1 to metabolic disease are not completely understood. Here, we compared the metabolic phenotype of C57BL/6J wild typ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.RA120001141
更新日期:2020-12-09 00:00:00
abstract::Zonation affects liver parenchymal cell function and metabolism as well as nonparenchymal cell activation, but whether VLDL production is zonated has yet to be elucidated. Infection induces enhanced VLDL secretion by the liver. Ex vivo studies were undertaken to examine the liver heterogeneity for VLDL formation and s...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M500003-JLR200
更新日期:2005-05-01 00:00:00
abstract::An in vitro method is presented which measures valid, unidirectional uptake rates for lipids across the intestinal brush border. This method combines analysis by a newly devised, double isotope counting system for solubilized tissue with the use of a nonabsorbable marker to correct gross uptake determinations for cont...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1972-03-01 00:00:00
abstract::We determined the effect of storage at -70 degrees C on the determination of plasma high density lipoprotein (HDL)-cholesterol. Plasma from 106 subjects was stored for 1, 6, and 12 months, then treated with heparin and MnCl2 to remove other lipoproteins, and HDL-cholesterol was measured. The mean HDL-cholesterol level...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1982-11-01 00:00:00
abstract::Rabbits were fed either 10% coconut oil, 10% coconut oil and 1% beta-sitosterol, 10% coconut oil and 1% cholesterol, or 10% coconut oil and 1% beta-sitosterol plus 1% cholesterol for 4 weeks. Microsomal membranes from intestines of animals fed the 1% beta-sitosterol diet had 48% less cholesterol and were enriched twof...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1983-04-01 00:00:00
abstract::In vitro studies show that docosahexaenoic acid (DHA) can be released from membrane phospholipid by Ca(2+)-independent phospholipase A(2) (iPLA(2)), Ca(2+)-independent plasmalogen PLA(2) or secretory PLA(2 (sPLA2)), but not by Ca(2+)-dependent cytosolic PLA(2) (cPLA2), which selectively releases arachidonic acid (AA)....
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M006262
更新日期:2010-08-01 00:00:00
abstract::Thus far, liver, intestine, heart, and placenta have been shown to secrete apolipoprotein (apo)B-containing lipoproteins. In the present study, we first investigated lipoproteins in human follicular fluid (FF), surrounding developing oocytes within the ovary, as well as in corresponding plasma samples (n = 12). HDL ch...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M005181
更新日期:2010-08-01 00:00:00
abstract::Native LDL (nLDL) increases expression of adhesion molecules on endothelial cells through induction of Ca(2+) mobilization. Ca(2+) mobilization is also involved in the induction of proinflammatory cytokines, important mediators involved in atherogenesis. The aim of the study was to evaluate the capacity of nLDL to aff...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.m100254-jlr200
更新日期:2002-07-01 00:00:00
abstract::Small angle X-ray diffraction was used to examine arterial smooth muscle cell (SMC) plasma membranes isolated from control and cholesterol-fed (2%) atherosclerotic rabbits. A microsomal membrane enriched with plasma membrane obtained from animals fed cholesterol for up to 13 weeks showed a progressive elevation in the...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1998-05-01 00:00:00
abstract::The absorption and distribution of deuterated trans- and cis-13-octadecenoic acid (13t-18:1 and 13c-18:1) in plasma lipids were compared to deuterated cis-9-octadecenoic acid (9c-18:1) in two young adult male subjects. A mixture of triglycerides was fed in a multiple-labeled experiment where each triglyceride containe...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1983-01-01 00:00:00
abstract::Subcellular localization of nonesterified cholesterol has been determined in normal human fibroblasts from cultures incubated with human low density lipoprotein (LDL). Nonesterified and esterified cholesterol content of fibroblasts, grown initially in the absence of cholesterol, increased significantly after a 1-hour ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1982-11-01 00:00:00
abstract::In an effort tao simulate the effects of insulin on fat cells prepared from fresh adipose tissue, pieces of epididymal adipose tissue were cultured in a medium containing charcoal-treated bovine serum albumin (BSA) with a gas phase of 100% O2. Using this system, the insulin effect on [1-14C]glucose oxidation was retai...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1982-02-01 00:00:00
abstract::LCAT plays a key role in the maturation of HDL, as evidenced by low HDL-cholesterol levels in carriers of deleterious mutations in LCAT. However, the role of LCAT in atherosclerosis is unclear. We set out to study this in a prospective study. Plasma LCAT levels, which strongly correlate with LCAT activity, were measur...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/P900038-JLR200
更新日期:2010-02-01 00:00:00
abstract::This study was undertaken to determine the mechanisms that regulate cholesterol synthesis in vivo and to quantitate the relative importance of the liver and extrahepatic tissues as sites for sterol synthesis. Rats were administered [3H]water intravenously and killed 1 hour later. The amount of [3H]water incorporated i...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1980-03-01 00:00:00
abstract::The relationship between overnight postabsorptive (fasting) respiratory exchange ratio (RER) and plasma FFA concentrations was addressed using data from three separate protocols, each of which involved careful control of the antecedent diet. Protocol 1 examined the relationship between fasting RER and the previous day...
journal_title:Journal of lipid research
pub_type: 临床试验,杂志文章
doi:10.1194/jlr.M900021-JLR200
更新日期:2009-09-01 00:00:00
abstract::Bile acids play important roles in the regulation of lipid, glucose, and energy homeostasis. Recent studies suggest that glucose regulates gene transcription in the liver. The aim of this study was to investigate the potential role of glucose in regulation of bile acid synthesis in human hepatocytes. High glucose stim...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M002782
更新日期:2010-04-01 00:00:00