Abstract:
:Sterol 27-hydroxylase, the mitochondrial enzyme that catalyzes the first step in oxidation of the sterol side chain in hepatic bile acid synthesis, also catalyzes the synthesis of 27-hydroxycholesterol from cholesterol. We have developed a high performance liquid chromatography (HPLC) assay for this enzyme, using either endogenous or exogenous cholesterol as substrate and cholesterol oxidase to convert 27-hydroxycholesterol to 4-cholesten-27-hydroxy-3-one. The alpha,beta-unsaturated ketone product was separated by normal phase HPLC and quantitated via absorption at 240 nm. Addition of cholesterol dissolved in 2-hydroxypropyl-beta-cyclodextrin to the assay mixture raised the enzyme activity of rat liver mitochondria more than 10-fold. 2-Hydroxypropyl-beta-cyclodextrin itself was partially effective, apparently by making more endogenous cholesterol accessible to the enzyme. Availability of cholesterol to the enzyme limits synthesis of 27-hydroxycholesterol in rat liver. Using our assay to simultaneously determine the activities of cholesterol 7 alpha-hydroxylase and cholesterol 27-hydroxylase in rat liver homogenates, we demonstrated that the two enzymes are separately regulated.
journal_name
J Lipid Resjournal_title
Journal of lipid researchauthors
Petrack B,Latario BJsubject
Has Abstractpub_date
1993-04-01 00:00:00pages
643-9issue
4eissn
0022-2275issn
1539-7262journal_volume
34pub_type
杂志文章abstract::Based on our previous observation that monoclonal antibody anti-apoD-4E11 reacted with several HDL proteins we studied them further with three questions in mind: i) is there common protein polymorphism in healthy individuals? ii) how many proteins are present and what are their characteristics? iii) are they all apoli...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1989-06-01 00:00:00
abstract::Genome-wide association (GWA) studies represent a powerful strategy for identifying susceptibility genes for complex diseases in human populations but results must be confirmed and replicated. Because of the close homology between mouse and human genomes, the mouse can be used to add evidence to genes suggested by hum...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M009175
更新日期:2011-06-01 00:00:00
abstract::Previously, we have shown that lipid-free apoA-I, when incubated with fibroblasts, will produce lipoproteins of pre-alpha mobility (Asztalos, B. F., et al. 1997. Arterioscler. Thromb. Vasc. Biol. 17: 1630-1636). In order to understand the nature of these pre-alpha particles, we further characterized their lipid conten...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1998-08-01 00:00:00
abstract::Insulin resistance (IR) is associated with elevated plasma levels of triglyceride-rich lipoproteins (TRLs) of intestinal origin. However, the mechanisms underlying the overaccumulation of apolipoprotein (apo)B-48-containing TRLs in individuals with IR are not yet fully understood. This study examined the relationships...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M040071
更新日期:2014-01-01 00:00:00
abstract::Seven Z-octadecenoic acids having the double bond located in positions 6Z to 13Z were photooxidized. The resulting hydroperoxy-E-octadecenoic acids [HpOME(E)] were resolved by chiral phase-HPLC-MS, and the absolute configurations of the enantiomers were determined by gas chromatographic analysis of diastereoisomeric d...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M018259
更新日期:2011-11-01 00:00:00
abstract::The alpha-naphthylisothiocyanate (ANIT)-treated rat was evaluated as a model for lipoprotein metabolism in cholestatic liver disease. Alterations in lipoprotein composition over a period of 120 h after ANIT treatment (100 mg/kg) were studied. Eighteen hours after treatment, plasma bilirubin and bile acid levels began ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1996-05-01 00:00:00
abstract::Male Sprague-Dawley rats were fed diets that contained 20% by weight soybean oil or rapeseed oil (21% and 43% erucic acid) for 7 days. The rapeseed oil diets increased the cardiac triacylglycerol content 5-fold and 25-fold, respectively, above control values. Hearts were removed from the animals and perfused with modi...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1993-09-01 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::Human lysosomal acid lipase/cholesteryl ester hydrolase (hLAL) is essential for the intralysosomal metabolism of cholesteryl esters and triglycerides taken up by receptor-mediated endocytosis of lipoprotein particles. The key role of the enzyme in intracellular lipid homeostasis is illustrated by two lysosomal storage...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1999-02-01 00:00:00
abstract::We investigated, in the present study, the role of reactive oxygen intermediates (ROI) in the control of macrophage lipoprotein lipase (LPL) secretion. Exposure of murine macrophages to increasing concentrations of hydrogen peroxide (H2O2) resulted in enhanced basal LPL production and mRNA levels. The increase of LPL ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1996-04-01 00:00:00
abstract::In a randomized, cross-over feeding trial involving 10 men with polygenic hypercholesterolemia, a control, Mediterranean-type cholesterol-lowering diet, and a diet of similar composition in which walnuts replaced approximately 35% of energy from unsaturated fat, were given for 6 weeks each. Compared with the control d...
journal_title:Journal of lipid research
pub_type: 临床试验,杂志文章,随机对照试验
doi:
更新日期:2001-12-01 00:00:00
abstract::In promoting oxidation of 0.02 m potassium linoleate in a buffered (pH 7.0) aqueous dispersion at 37 degrees C, ascorbic acid at low concentrations (1.8 x 10(-6) and 1.8 x 10(-5) m) in combination with copper (1.3 x 10(-7) to 1.3 x 10(-3) m) had greater catalytic activity than the additive activity of the two catalyst...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1969-09-01 00:00:00
abstract::After crossing floxed stearoyl-CoA desaturase-1 (Scd1fl/fl) mice with LDL receptor-null (ldlr-/-) mice, and then Villin Cre (VilCre) mice, enterocyte Scd1 expression in Scd1fl/fl/ldlr-/-/VilCre mice was reduced 70%. On Western diet (WD), Scd1fl/fl/ldlr-/- mice gained more weight than Scd1fl/fl/ldlr-/-/VilCre mice (P <...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M083527
更新日期:2018-10-01 00:00:00
abstract::Ethanolamine phosphotransferase (EPT)1, also known as selenoprotein 1 (SELENOI), is an enzyme that transfers phosphoethanolamine from cytidine diphosphate-ethanolamine to lipid acceptors to produce ethanolamine glycerophospholipids, such as diacyl-linked phosphatidylethanolamine (PE) and ether-linked plasmalogen [1-al...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.P081620
更新日期:2018-06-01 00:00:00
abstract::Nuclear hormone receptors liver X receptor (LXRalpha and LXRbeta) ligands are attractive approaches for the treatment of dyslipidemia and atherosclerosis. To further elucidate the function of LXRalpha in liver lipid metabolism in a disease-relevant animal model, the KKAy mouse, we used adenoviral vectors to selectivel...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M700571-JLR200
更新日期:2009-01-01 00:00:00
abstract::In eukaryotes, many cell surface proteins are attached to the plasma membrane via a glycolipid glycosylphosphatidylinositol (GPI) anchor. GPI-anchored proteins (GPI-APs) receive the GPI anchor as a conserved posttranslational modification in the lumen of the endoplasmic reticulum (ER). After anchor attachment, the GPI...
journal_title:Journal of lipid research
pub_type: 杂志文章,评审
doi:10.1194/jlr.R062760
更新日期:2016-03-01 00:00:00
abstract::In addition to their classical roles as detergents to aid in the process of digestion, bile acids have been identified as important signaling molecules that function through various nuclear and G protein-coupled receptors to regulate a myriad of cellular and molecular functions across both metabolic and nonmetabolic p...
journal_title:Journal of lipid research
pub_type: 杂志文章,评审
doi:10.1194/jlr.R054114
更新日期:2015-06-01 00:00:00
abstract::Long-chain polyunsaturated fatty acids (PUFA) orchestrate immunity and inflammation through their capacity to be converted to potent inflammatory mediators. We assessed associations of FADS gene cluster polymorphisms and fasting serum PUFA concentrations in a fully ascertained, geographically isolated founder populati...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M008359
更新日期:2010-09-01 00:00:00
abstract::Precipitation of cholesterol crystals from vesicles is an important step in the pathogenesis of cholesterol gallstones. Little is known, however, about the kinetics and the mechanisms involved in cholesterol crystallization. Therefore, the time course of cholesterol crystal precipitation and lipid exchange between ves...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1994-06-01 00:00:00
abstract::The apoproteins of serum lipoproteins and of lipoproteins present in a nonrecirculating perfusate of rat liver were compared by immunochemical, gel electrophoretic, and solubility techniques. Serum and perfusate very low density lipoprotein apoprotein composition were not different. No evidence for the presence of a l...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1976-01-01 00:00:00
abstract::Decreased HDL-cholesterol (HDL-C) and familial combined hyperlipidemia (FCHL) are the two most common familial dyslipidemias predisposing to premature coronary heart disease (CHD). These dyslipidemias share many phenotypic features, suggesting a partially overlapping molecular pathogenesis. This was supported by our p...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M400141-JLR200
更新日期:2004-10-01 00:00:00
abstract::A deficiency of lysosomal phospholipase A2 (LPLA2) causes macrophage-associated phospholipidosis, suggesting that the enzyme is important in the lipid catabolism. Because LPLA2 is secreted by macrophages, extracellular LPLA2 activity may potentially reflect a change in macrophage activation. In this report, the detect...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.D007146
更新日期:2010-08-01 00:00:00
abstract::Recent evidence suggests the possibility that macrophages can influence lipoprotein metabolism. Therefore we investigated the ability of cultured macrophages to alter low density lipoprotein (LDL) uptake in a human liver cell line (HepG2). Conditioned media from phlogogenic-induced mouse peritoneal macrophages or from...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1991-12-01 00:00:00
abstract::Using [13C]-tracers and direct fetal doses, we show for the first time that the fetal primate converts alpha-linolenic acid (18:3) to docosahexaenoic acid (22:6) in vivo, and we estimate the relative bioefficacy of the two substrates for brain 22:6 accretion. Pregnant female baboons consumed a diet free of long chain ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:2001-04-01 00:00:00
abstract::We propose a simple mathematical model to account for the coupling of secretion rates of bile salts, lecithin, and cholesterol into bile. The model assumes that: 1) molecules of "biliary" lecithin and cholesterol enter a functional compartment located in the endoplasmic reticulum of the hepatocyte from which they are ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1984-09-01 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
abstract::Previous studies from our laboratory indicated that pre-germinated brown rice (PR) contained certain unknown bioactive lipids that activated two enzymes related to diabetes: Na+/K+ATPase and homocysteine-thiolactonase. In this paper, we report on the isolation and structural characterization of the activator lipids fr...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M800257-JLR200
更新日期:2008-10-01 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::Genetic defects in SAR1B GTPase inhibit chylomicron (CM) trafficking to the Golgi and result in a huge intraenterocyte lipid accumulation with a failure to release CMs and liposoluble vitamins into the blood circulation. The central aim of this study is to test the hypothesis that SAR1B deletion (SAR1B-/- ) disturbs e...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.RA119000119
更新日期:2019-10-01 00:00:00
abstract::Paraoxonases (PONs) are a small family of antioxidant enzymes whose antiatherogenic activity is well known. The aim of the present study was the evaluation of the effects of moderate aerobic training on their expression using a rat model. In order to discriminate between PON1 and PON3 enzymatic activity, we took advan...
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