Abstract:
:The hepatic uptake of intravenously injected beta-very low density lipoprotein (beta-VLDL) in rabbits fed 2% (w/w) cholesterol for 3 weeks was investigated. In vitro studies were also conducted to examine the specificity and the capacity of the uptake in isolated liver parenchymal cells. The hepatic uptake of beta-VLDL was 15.8 +/- 6.7% (n = 6) in the cholesterol-fed rabbits as compared to 26.6 +/- 7.5% (n = 6) of the injected dose in control rabbits (P < 0.05). Although this is a fractional reduction, it represents a more than 10-fold increase in absolute hepatic uptake of lipoproteins in the cholesterol-fed rabbits. In these animals the liver parenchymal, endothelial, and Kupffer cells took up 10.2 +/- 2.7%, 3.0 +/- 0.9%, and 1.8 +/- 0.4% of the injected dose, respectively, compared to 25.9 +/- 6.1%, 3.6 +/- 1.6%, and 1.5 +/- 0.8% of the injected dose in chow-fed controls. However, taking into account the high plasma lipoprotein levels in the cholesterol-fed rabbits, the absolute cellular uptake was 10-fold increased in the parenchymal liver cells and more than 20-fold increased in the nonparenchymal cells. In vitro results indicated a 40% down-regulation of the specific receptor for beta-VLDL in the parenchymal cells, and this, together with an increased competition for binding sites in the hypercholesterolemic rabbits, probably explains the reduced uptake of beta-VLDL in terms of % of injected dose observed in vivo. In vitro data suggested that the receptor involved in both hypercholesterolemic and normolipemic rabbits was the apolipoprotein (apo) B,E receptor. On a per cell basis, parenchymal cells from chow-fed control animals took up 2.4 +/- 0.8% of the injected dose per 10(9) cells; this uptake was reduced to 1.1 +/- 0.5% in hypercholesterolemic animals. No differences in uptake of beta-VLDL in nonparenchymal liver cells were observed on a per cell basis between the two feeding groups, indicating that binding sites involved in this uptake are not down-regulated by cholesterol feeding. On the contrary, the absolute uptake in the nonparenchymal liver cells is greatly increased in hypercholesterolemic rabbits as compared to controls. In cholesterol-fed rabbits the three different liver cell types took up approximately the same amount of beta-VLDL per cell. The liver nonparenchymal cells, therefore, assume a prominent role in uptake of beta-VLDL in hypercholesterolemic rabbits, accounting for more than 30% of the total hepatic uptake as compared to 16% in control animals.(ABSTRACT TRUNCATED AT 400 WORDS)
journal_name
J Lipid Resjournal_title
Journal of lipid researchauthors
Gudmundsen O,Berg T,Roos N,Nenseter MSsubject
Has Abstractpub_date
1993-04-01 00:00:00pages
589-600issue
4eissn
0022-2275issn
1539-7262journal_volume
34pub_type
杂志文章abstract::Total serum free fatty acids (FFAt) levels provide an important measure of the physiologic state. Most of the FFA in serum is bound to albumin; a small portion, however, is unbound. This study presents the first measurements of serum unbound free fatty acid (FFAu) concentrations. These measurements were made possible ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1995-02-01 00:00:00
abstract::Human striated muscle samples, from male control and Duchenne muscular dystrophy-affected children, were subjected to cluster-time-of-flight secondary ion mass spectrometry (cluster-ToF-SIMS) imaging using a 25 keV Bi(3)(+) liquid metal ion gun under static SIMS conditions. Spectra and ion density maps, or secondary i...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M700421-JLR200
更新日期:2008-02-01 00:00:00
abstract::To study the role of phospholipids in the lipophorin structure, they were removed by phospholipase A2 treatment. Fluorescence lifetimes and accessibility to acrylamide quenching of different diphenylhexatrienyl derivatives, which were used as analogues of the different lipid components, indicate a surface localization...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1996-10-01 00:00:00
abstract::Loss of function of Niemann-Pick C1 (NPC1) leads to lysosomal free cholesterol storage, resulting in the neurodegenerative disease Niemann-Pick disease type C (NPC). Significant numbers of patients with NPC also suffer from liver disease. Currently, no treatments exist that alter patient outcome, and it is unknown if ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M007211
更新日期:2010-08-01 00:00:00
abstract::In this study, we examined effects of retinol deficiency and three retinoids, all-trans-retinoic acid, 13-cis-retinoic acid, and etretin, the aromatic derivative of retinoic acid on nuclear retinoic acid receptor isoforms alpha, beta, and gamma mRNA in rat adipose tissue. Retinol deficiency caused an almost 50% decrea...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1992-03-01 00:00:00
abstract::Lysophosphatidylcholine (lysoPC) is a bioactive phospholipid that is involved in atherogenesis and inflammatory processes. However, the present understanding of mechanisms whereby lysophosphatidylcholine exerts its pathophysiological actions is incomplete. In the present work, we show that lysoPC stimulates phospholip...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1999-06-01 00:00:00
abstract::Cyclophosphamide injection into the fasted rabbit induces a hypertriglyceridemia (4.6 mM vs. 0.8 mM in controls) and a defect of lipoprotein lipase (LPL), as measured in post-heparin plasma (PHP). In contrast, administration of the drug into fed animals tends to increase PHP-LPL. The effects of cyclophosphamide on LPL...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1993-01-01 00:00:00
abstract::ACAT catalyzes the formation of cholesteryl esters from cholesterol and long-chain fatty acids. There are two known genes encoding the two ACAT enzymes, ACAT1 and ACAT2 (also known as Soat1 and Soat2). In adult humans, ACAT1 is present in most tissues, whereas ACAT2 is localized to enterocytes and hepatocytes. In this...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M400450-JLR200
更新日期:2005-09-01 00:00:00
abstract::Percent cholesterol absorption was measured in 94 normal subjects aged 17- 80 years while consuming diets generally low in cholesterol (mean intake = 226 +/- 126 mg/day). A new dual stable isotope method was used where a cholesterol tracer containing 6 extra mass units was given intravenously and another tracer with 5...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1999-02-01 00:00:00
abstract::Several different processes involved in the metabolic fate of docosahexaenoic acid (DHA, C22:6n-3) and its precursor in the biosynthesis route, C24:6n-3, were studied. In cultured skin fibroblasts, the oxidation rate of [1-14C] 24:6n-3 was 2.7 times higher than for [1-14C]22:6n-3, whereas [1-14C]22:6n-3 was incorporat...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M300223-JLR200
更新日期:2003-10-01 00:00:00
abstract::Dietary fiber is plant-derived material that is resistant to digestion by human alimentary enzymes. Fiber may be divided into two broad chemical classes: 1) non-alpha-glucan polysaccharides (cellulose, hemicelluloses, and pectins) and 2) lignins. Dietary fiber behaves within the gastrointestinal tract as a polymer mat...
journal_title:Journal of lipid research
pub_type: 杂志文章,评审
doi:
更新日期:1982-02-01 00:00:00
abstract::Serine palmitoyltransferase (SPT) catalyzes the rate-limiting step of condensation of L-serine and palmitoyl-CoA to form 3-ketodihydrosphingosine (3KDS). Here, we report a HPLC-ESI-MS/MS method to directly quantify 3KDS generated by SPT. With this technique, we were able to detect 3KDS at a level comparable to that of...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.D078535
更新日期:2018-01-01 00:00:00
abstract::Oligosaccharyl phosphates (OSPs) are hydrolyzed from oligosaccharide-diphosphodolichol (DLO) during protein N-glycosylation by an uncharacterized process. An OSP-generating activity has been reported in vitro, and here we asked if its biochemical characteristics are compatible with a role in endoplasmic reticulum (ER)...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M067330
更新日期:2016-06-01 00:00:00
abstract::The ternary phase diagram of cholesteryl myristate--dimyristoyl lecithin--water has been determined by polarizing light microscopy, scanning calorimetry, and x-ray diffraction. Hydrated dimyristoyl lecithin forms a lamellar liquid--crystalline phase (L alpha) at temperatures greater than 23 degrees C into which limite...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1979-02-01 00:00:00
abstract::The demand to study the cellular localization of specific lipids has led to recent advances in lipid probes and microscopy. Alkyne lipids bear a small, noninterfering tag and can be detected upon click reaction with an azide-coupled reporter. Fluorescent alkyne lipid imaging crucially depends on appropriate azide repo...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.D070565
更新日期:2016-10-01 00:00:00
abstract::Choline kinase catalyzes the phosphorylation of choline, the first step of phospholipid synthesis. Increased phosphorylation of choline is a hallmark characteristic of the malignant phenotype in a variety of neoplasms. However, in hypoxic cancer cells, choline phosphorylation is decreased. To understand the mechanism ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M021030
更新日期:2012-01-01 00:00:00
abstract::To consider possible interaction of the phospholipid membrane with calcium ions, crystal structures of calcium dl-alpha- and beta-glycerophosphates (alpha- and beta-CaGs, respectively) were investigated by X-ray diffraction methods. After many attempts, relatively large single crystals of beta-CaG were prepared from t...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1992-07-01 00:00:00
abstract::Biosynthesis of 5,15-dihydroxyeicosatetraenoic acid (5,15-diHETE) in leukocytes involves consecutive oxygenation of arachidonic acid by 5-lipoxygenase (LOX) and 15-LOX in either order. Here, we analyzed the contribution of cyclooxygenase (COX)-2 to the biosynthesis of 5,15-diHETE and 5,11-diHETE in isolated human leuk...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M017822
更新日期:2012-01-01 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::The inverse relationship between plasma levels of high density lipoprotein (HDL) and coronary heart disease rates has suggested that HDL might influence body stores of cholesterol. Therefore, we have investigated potential relationships between the parameters of body cholesterol metabolism and the plasma levels of HDL...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1985-09-01 00:00:00
abstract::The vitamin D signal transduction system involves a series of cytochrome P450-containing sterol hydroxylases to generate and degrade the active hormone, 1α,25-dihydroxyvitamin D3, which serves as a ligand for the vitamin D receptor-mediated transcriptional gene expression described in companion articles in this review...
journal_title:Journal of lipid research
pub_type: 杂志文章,评审
doi:10.1194/jlr.R031534
更新日期:2014-01-01 00:00:00
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journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1971-03-01 00:00:00
abstract::Prostaglandin (PG)E(2) is relevant in tumor biology, and interactions between tumor and stroma cells dramatically influence tumor progression. We tested the hypothesis that cross-talk between head and neck squamous cell carcinoma (HNSCC) cells and fibroblasts could substantially enhance PGE(2) biosynthesis. We observe...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M019695
更新日期:2012-04-01 00:00:00
abstract::Subnormal HDL-cholesterol (HDL-C) and apolipoprotein (apo)AI levels are characteristic of familial hypercholesterolemia (FH), reflecting perturbed intravascular metabolism with compositional anomalies in HDL particles, including apoE enrichment. Does LDL-apheresis, which reduces HDL-cholesterol, apoAI, and apoE by ads...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.P016816
更新日期:2011-12-01 00:00:00
abstract::Apolipoprotein A-II (apoA-II) is the second major apolipoprotein following apolipoprotein A-I (apoA-I) in HDL. ApoA-II has multiple physiological functions and can form senile amyloid fibrils (AApoAII) in mice. Most circulating apoA-II is present in lipoprotein A-I/A-II. To study the influence of apoA-I on apoA-II and...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M013235
更新日期:2011-08-01 00:00:00
abstract::Vitamin A-transporting protein in chicken plasma was purified by column chromatography on DEAE-Sephadex and Sephadex G-100; the protein formed a complex of retinol-binding protein (RBP) with prealbumin (PA). The molecular weight of the 1:1 molar complex was estimated to be 76,000 by gel filtration, and the sedimentati...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1975-05-01 00:00:00
abstract::Apolipoprotein E plays a critical role in plasma lipoprotein clearance. Peptide models of a highly conserved, N-terminal domain of this protein have been shown to increase the binding of low density lipoprotein (LDL) to fibroblast cell surfaces independently of the low density lipoprotein receptor. Here we provide dat...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1999-04-01 00:00:00
abstract::Apolipoprotein A-V (apoA-V) first gained attention as a regulator of triglycerides through transgenic mouse studies. Furthermore, peroxisome proliferator-activated receptor alpha (PPARalpha) agonists such as fenofibrate increase apoA-V mRNA expression. Our group recently developed the first assay to quantitate serum a...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.C500010-JLR200
更新日期:2005-08-01 00:00:00
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::Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in the United States and, indeed, worldwide. It has become a global public health issue. In the United States, the prevalence in the general population is estimated at approximately 20%, while that in the morbidly obese population at approximate...
journal_title:Journal of lipid research
pub_type: 杂志文章,评审
doi:10.1194/jlr.R800089-JLR200
更新日期:2009-04-01 00:00:00