Abstract：
:The extent to which cholesterol synthesis is modulated in macrophage foam cells by changes in cholesterol influx and efflux was determined using thioglycollate-elicited peritoneal macrophages from normal and cholesterol-fed White Carneau (WC) and Show Racer (SR) pigeons. In peritoneal macrophages from normocholesterolemic pigeons, sterol synthesis from [(14)C]-acetate was down-regulated by more than 90% following incubation in vitro with beta-VLDL. Sterol synthesis was increased when the cellular free cholesterol concentration was decreased in response to stimulation of cholesterol efflux with apoHDL/phosphatidylcholine vesicles and cyclodextrin. Peritoneal macrophages isolated from hypercholesterolemic pigeons were loaded with cholesterol to levels similar to foam cells from atherosclerotic plaques (375-614 microg/mg cell protein), and had an extremely low rate of sterol synthesis. When cholesterol efflux was stimulated in these cells, sterol synthesis increased 8 to 10-fold, even though the cells remained grossly loaded with cholesterol. Cholesterol efflux also stimulated HMG-CoA reductase activity and LDL receptor expression. This suggests that only a small portion of the total cholesterol pool in macrophage foam cells was responsible for regulation of sterol synthesis, and that cholesterol generated by hydrolysis of cholesteryl esters was directed away from the regulatory pool by efflux from the cells. When the increase in sterol synthesis was blocked with the HMG-CoA reductase inhibitor mevinolin, there was no difference in the cholesterol content of the cells, or in the mass efflux of cholesterol into the culture medium.Thus, under these conditions, the increase in cholesterol synthesis during stimulation of cholesterol efflux does not appear to contribute significantly to the mass of cholesterol in these macrophage foam cells. Whether a similar situation exists in vivo is unknown.
journal_name
J Lipid Resjournal_title
Journal of lipid researchauthors
Nordskog BK,Reagan JW Jr,St Clair RWkeywords:
subject
Has Abstractpub_date
1999-10-01 00:00:00pages
1806-17issue
10eissn
0022-2275issn
1539-7262journal_volume
40pub_type
杂志文章abstract：:Cytolipin R, a ceramide tetrahexoside isolated from rat lymphosarcoma, was studied by sequential hydrolysis with specific glycosidases which revealed the anomeric configurations of the glycosidic bonds. Sugar linkages were established by combined gas-liquid chromatography and mass spectrometry of the partially methyla...
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, 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：:Rates of conversion of alpha-linolenic acid (alpha-LNA, 18:3n-3) to docosahexaenoic acid (DHA, 22:6n-3) by the mammalian brain and the brain's ability to upregulate these rates during dietary deprivation of n-3 polyunsaturated fatty acids (PUFAs) are unknown. To answer these questions, we measured conversion coefficie...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M600549-JLR200
更新日期：2007-05-01 00:00:00
abstract：:We report the clinical phenotype in three kindreds with familial heterozygous hypobetalipoproteinemia (FHBL) carrying novel truncated apolipoprotein Bs (apoBs) of different sizes (apoB-8.15, apoB-33.4 and apoB-75.7). In D.A. kindred, we found three carriers of a C-deletion in exon 10 leading to the synthesis of apoB-8...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：2001-10-01 00:00:00
abstract：:Acyl-CoA:monoglyceride acyltransferase in microsomal preparations from the small intestine of the rat has been measured by means of continuous recording spectrophotometry. The reaction of 5,5'-dithiobis(2-nitrobenzoic acid) with CoA has been employed for this assay and optimal conditions for the reaction have been def...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1969-07-01 00:00:00
abstract：:Thyroid hormone lowers serum cholesterol and alters sterol metabolic processes. This laboratory has previously reported increased biliary lipid secretion as an early effect of triiodothyronine (T3) in the rat. To evaluate whether the bile lipid action of T3 is a primary or secondary effect, the isolated-perfused rat l...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1992-10-01 00:00:00
abstract：:Selenocysteine (Sec) insertion sequence-binding protein 2 (SBP2) is essential for the biosynthesis of Sec-containing proteins, termed selenoproteins. Subjects with mutations in the SBP2 gene have decreased levels of several selenoproteins, resulting in a complex phenotype. Selenoproteins play a significant role in ant...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M059105
更新日期：2015-11-01 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
abstract：:It is becoming increasingly accepted that removal of cellular cholesterol occurs by at least two pathways, one involving the well-described aqueous diffusion mechanism and another promoted by lipid-free apolipoproteins. We compared the contribution of apolipoprotein-dependent and -independent pathways, taking into con...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1997-09-01 00:00:00
abstract：:Sphingolipids (SLs) have been implicated in numerous important cellular biologies; however, their study has been hindered by the complexities of SL metabolism. Furthermore, enzymes of SL metabolism represent a dynamic and interconnected network in which one metabolite can be transformed into other bioactive SLs throug...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M089714
更新日期：2019-04-01 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：:Increased plasma concentrations of apolipoprotein A-IV (apoA-IV) in chronic renal disease suggest a metabolic role of the kidney for this antiatherogenic protein. Therefore, we investigated patients with various forms of proteinuria and found increased serum concentrations of apoA-IV in 124 nephrotic patients compared...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M600178-JLR200
更新日期：2006-09-01 00:00:00
abstract：:Cholesterol efflux (CE) capacity has been inversely associated with atherosclerosis and may provide an insight on inflammation occurring in human immunodeficiency virus (HIV) individuals. We address this by studying CE in HIV patients at different stages of HIV disease progression. In this cross-sectional study, CE fr...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M088153
更新日期：2018-11-01 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：:Plasma phospholipid transfer protein (PLTP) is an important regulator of plasma HDL levels and HDL particle distribution. PLTP is present in plasma in two forms, one with high and the other with low phospholipid transfer activity. We have used the human hepatoma cell line, HepG2, as a model to study PLTP secreted from...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M300059-JLR200
更新日期：2003-09-01 00:00:00
abstract：:The infrared (IR) and nuclear magnetic resonance (NMR) spectra of eight Delta(24)-steroids and nine C-24 saturated steroids were examined. NMR spectra allow unambiguous assignment of the biologically important Delta(24)-bond; introduction of a Delta(24)-bond causes the appearance of peaks at Delta 1.60 and 1.68 associ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1968-01-01 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：:Conserved lysines and arginines within amino acids 140-150 of apolipoprotein (apo) E are crucial for the interaction between apoE and the low density lipoprotein receptor (LDLR). To explore the roles of amphipathic alpha-helix and basic residue organization in the binding process, we performed site-directed mutagenesi...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：2000-07-01 00:00:00
abstract：:Among the family of phospholipases A2 (PLA2s) are the Ca(2+)-independent PLA2s (iPLA2s) and they are designated group VI iPLA2s. In relation to secretory and cytosolic PLA2s, the iPLA2s are more recently described and details of their expression and roles in biological functions are rapidly emerging. The iPLA2s or pat...
journal_title：Journal of lipid research
pub_type： 杂志文章,评审
doi：10.1194/jlr.R058701
更新日期：2015-09-01 00:00:00
abstract：:Small dense LDL (sdLDL) has been reported to be more atherogenic than large buoyant LDL (lbLDL). We examined the metabolism and protein composition of sdLDL and lbLDL in six subjects with combined hyperlipidemia on placebo and rosuvastatin 40 mg/day. ApoB-100 kinetics in triglyceride-rich lipoproteins (TRLs), lbLDL (d...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M073882
更新日期：2017-07-01 00:00:00
abstract：:Niemann-Pick C1-like 1 (NPC1L1) is a recently identified protein that mediates intestinal cholesterol absorption and regulates biliary cholesterol excretion. The itineraries and kinetics of NPC1L1 trafficking remain uncertain. In this study, we have visualized movement of NPC1L1-enhanced green fluorescent protein (NPC...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M800145-JLR200
更新日期：2008-09-01 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：:Free fat cells and stromal-vascular cells were prepared from rat adipose tissue by incubation with collagenase. NH(4)OH-NH(4)Cl extracts of acetone-ether powders prepared from fat cells contained lipoprotein lipase activity but extracts of stromal-vascular cells did not. Intact fat cells released lipoprotein lipase ac...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1969-07-01 00:00:00
abstract：:13C nuclear magnetic resonance (NMR) spectra were obtained at 50.3 and 100.5 MHz for methanolic and aqueous mixtures of sodium taurocholate, 1-monocapryloyl-rac-glycerol, and caprylic acid. Distortionless Enhancement by Polarization Transfer (DEPT) was used to improve spectral sensitivity and resolution, and to genera...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1992-03-01 00:00:00
abstract：:The dynamics of human apoE metabolism were explored by examining the effects of alimentary lipemia and postheparin lipolysis on the plasma level and lipoprotein distribution of apoE. In the studies of alimentary lipemia, fasting and postprandial plasma samples were obtained from five normal adult males, each of whom d...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1982-12-01 00:00:00
abstract：:Experimental approaches involving the perfusion of tissues and organs offer the advantage of improved physiological relevance over the use of isolated tissues or cells while at the same time being much more controlled and tissue-specific than studies in vivo. Nevertheless, there have been few metabolic studies perform...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.D500016-JLR200
更新日期：2005-08-01 00:00:00
abstract：:The content of serum gangliosides was examined in VM and C57BL/6J (B6) mice that contained subcutaneous metastatic (VM) and non-metastatic (CT-2A) brain tumors, respectively. Gas-liquid chromatography (GLC) and high performance thin-layer chromatography (HPTLC) were used to analyze the serum gangliosides. N-glycolylne...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1994-01-01 00:00:00
abstract：:The effect of microbiological deconjugation of bile acids on total bile acid and neutral sterol fecal excretion by adult male rats has been studied. A screening method utilizing mice allowed selection of a Clostridium perfringens type A strain, which accelerated cholesterol catabolism in mice. When this species of bac...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1970-07-01 00:00:00
abstract：:The rate of lipolytic enzyme-catalyzed reactions yielding water-soluble products can be measured by isobaric titration. The method is based upon the measurement of the amount of substrate that must be added to a monalayer to maintain constant surface pressure during the course of the enzymatic reaction. The rate const...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1975-01-01 00:00:00
abstract：:Inhibition of Ehrlich ascites carcinoma respiration by aqueous extracts of oxidized linoleic or linolenic acid (aqueous emulsions UV-irradiated, 90 min) was associated entirely with relatively involatile compounds which were both thiobarbituric acid (TBA)-reactive and peroxidase-reactive. Inhibitory compounds were hea...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1966-05-01 00:00:00
