Abstract:
:The effects of eicosapentaenoic acid and oleic acid on lipid synthesis and secretion by HepG2 cells were examined to identify fatty acid specific changes in lipid metabolism that might indicate a basis for the hypolipidemic effect attributed to eicosapentaenoic acid and related n-3 fatty acids. Cellular glycerolipid synthesis, as determined by [3H]glycerol incorporation, increased in a concentration-dependent manner in cells incubated 4 h with either eicosapentaenoic acid or oleic acid at concentrations between 10 and 300 microM. [3H]Glycerol-labeled triglyceride was the principal lipid formed and increased approximately fourfold with the addition of 300 microM oleic acid or eicosapentaenoic acid. Both fatty acids also produced a 20-40% increase in the total cellular triglyceride mass. Although both fatty acids increased triglyceride synthesis to similar extents, eicosapentaenoic acid-treated cells secreted 40% less [3H]glycerol-labeled triglyceride than cells fed oleic acid. Cellular synthesis of [3H]glycerol-labeled phosphatidylethanolamine and phosphatidylcholine was also reduced by 40% and 30%, respectively, in cells given eicosapentaenoic acid versus cells given oleic acid. Similar results were obtained in determinations of radiolabeled oleic acid and eicosapentaenoic acid incorporation. At a fatty acid concentration of 300 microM, incorporation of radiolabeled eicosapentaenoic acid into cellular triglycerides was greater than the incorporation obtained with radiolabeled oleic acid, while the reverse relationship was observed for the formation of phosphatidylcholine from the same fatty acids. Eicosapentaenoic acid is as potent as oleic acid in inducing triglyceride synthesis but eicosapentaenoic acid is a poorer substrate than oleic acid for phospholipid synthesis. The intracellular rise in de novo-synthesized triglyceride in eicosapentaenoic acid-treated cells without corresponding increases in triglyceride secretion suggests that eicosapentaenoic acid is less effective than oleic acid in promoting the transfer of de novo-synthesized triglyceride to nascent very low density lipoproteins.
journal_name
J Lipid Resjournal_title
Journal of lipid researchauthors
Homan R,Grossman JE,Pownall HJsubject
Has Abstractpub_date
1991-02-01 00:00:00pages
231-41issue
2eissn
0022-2275issn
1539-7262journal_volume
32pub_type
杂志文章abstract::It was the aim of this study to i) compare the effects of glucose and other hexoses with that of oleate on secretion of apolipoproteins (apos) A-I and B by HepG2 cells, and ii) document the effect of various metabolic inhibitors on the secretion of these apos in the absence or presence of extra glucose/oleate. i) The ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1995-08-01 00:00:00
abstract::We have developed a simplified and improved high performance liquid chromatography (HPLC) method for the detection and quantitation of tissue lipid using a new laser light-scattering detector (Varex model ELSD II). This detector has a limit of sensitivity of 50 ng for neutral lipid and 200 ng for most phospholipids wi...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1990-11-01 00:00:00
abstract::We studied the biogenesis of apolipoprotein B (apoB) in primary hepatocytes isolated from hamster liver, an animal model with striking resemblance to humans in lipoprotein metabolism. Hamster hepatocytes were found to assemble and secrete apoB-containing lipoproteins at a density of VLDL. Intracellular mechanisms of a...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:2000-04-01 00:00:00
abstract::13C-NMR spectroscopy was used to examine the effect of side chain length on the ionization properties and transmembrane transport rate of 3 alpha,7 alpha-dihydroxy bile acids. When solubilized in taurocholate micelles, [23-13C]nor-chenodeoxycholic acid (nor-CDCA) had a pKa of 6.1, similar to that of CDCA (pKa 6.2), it...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1994-05-01 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::Neuroinflammation, caused by 6 days of intracerebroventricular infusion of a low dose of lipopolysaccharide (LPS; 0.5 ng/h), stimulates brain arachidonic acid (AA) metabolism in rats, but 6 weeks of lithium pretreatment reduces this effect. To further understand this action of lithium, we measured concentrations of ei...
journal_title:Journal of lipid research
pub_type: 杂志文章,收录出版
doi:10.1194/jlr.M002469
更新日期:2010-05-01 00:00:00
abstract::Spectrophotometric techniques for determining the activities of lipases, lysophospholipases, and phospholipases are reviewed. These methods involve the use of thioester substrate analogs as well as omega-nitrophenyl derivatives of the corresponding lipids. The most promising results are obtained with the thioester sub...
journal_title:Journal of lipid research
pub_type: 杂志文章,评审
doi:
更新日期:1984-12-15 00:00:00
abstract::The selective and reversible adsorption of bovine low density lipoproteins (LDL) by heparin-Sepharose has been exploited as the critical step in a procedure for the preparative isolation of very low density lipoproteins (VLDL)/chylomicrons, LDL, and high density lipoproteins (HDL) from bovine plasma. Molecular size ex...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1985-06-01 00:00:00
abstract::To assess the relationship between cholesterol synthesis and feedback inhibition of bile acid synthesis, we studied seven normal human subjects taking three different doses of chenodiol, 0, 5, and 15 mg/kg per day: once while taking no lovastatin and again while taking lovastatin 80 mg/day. Lovastatin and both doses o...
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:1994-08-01 00:00:00
abstract::Work by other investigators has shown that an increase in dietary content of monounsaturated fatty acids can result in a decreased plasma low density lipoprotein (LDL) cholesterol concentration. This observation, combined with the epidemiologic evidence that monounsaturated fat-rich diets are associated with decreased...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1990-10-01 00:00:00
abstract::Mixed background SHP(-/-) mice are resistant to diet-induced obesity due to increased energy expenditure caused by enhanced PGC-1α expression in brown adipocytes. However, congenic SHP(-/-) mice on the C57BL/6 background showed normal expression of PGC-1α and other genes involved in brown adipose tissue thermogenesis....
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M016048
更新日期:2011-12-01 00:00:00
abstract::Liver microsomal lipid peroxidation has been observed in fatal human CCl(4) poisoning, in rats with fatty livers induced by CCl(4) or by yellow phosphorus, and in mice poisoned with 1,1,2,2-tetrachloroethane. These observations suggest the possibility that other instances of toxic liver injury may involve lipid peroxi...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1971-11-01 00:00:00
abstract::Apolipoprotein E2 (apoE2)-associated hyperlipidemia is characterized by a disturbed clearance of apoE2-enriched VLDL remnants. Because excess apoE2 inhibits LPL-mediated triglyceride (TG) hydrolysis in vitro, we investigated whether direct or indirect stimulation of LPL activity in vivo reduces the apoE2-associated hy...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M800009-JLR200
更新日期:2008-05-01 00:00:00
abstract::The rate of removal of phosphatidylethanolamine and phosphatidylcholine from the plasma of rats treated with antiserum to hepatic lipase was measured. The hepatic lipase antiserum was injected intravenously into animals prior to injection of 32P-labeled chylomicrons or 32P-labeled high density lipoproteins. In experim...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1984-06-01 00:00:00
abstract::In specialized cell types, lysosome-related organelles support regulated secretory pathways, whereas in nonspecialized cells, lysosomes can undergo fusion with the plasma membrane in response to a transient rise in cytosolic calcium. Recent evidence also indicates that lysosome secretion can be controlled transcriptio...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M089979
更新日期:2019-04-01 00:00:00
abstract::The objective of this study was to establish a new lipoprotein lipase (LPL) and hepatic lipase (HL) activity assay method. Seventy normal volunteers were recruited. Lipase activities were assayed by measuring the increase in absorbance at 546 nm due to the quinoneine dye. Reaction mixture-1 (R-1) contained dioleoylgly...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M700528-JLR200
更新日期:2008-07-01 00:00:00
abstract::A rapid isocratic method for determining the total phosphatidylcholine and disaturated phosphatidylcholine levels in lung surfactant preparations by high performance liquid chromatography (HPLC) is described. The analysis was performed on a 3.9 x 300 mm mu-Porasil column with detection by refractive index. The lipids ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1989-04-01 00:00:00
abstract::Bovine aortic endothelial cells take up 12-hydroxyeicosatetraenoic acid (12-HETE), a lipoxygenase product formed from arachidonic acid. The uptake of [3H]12-HETE reached a maximum in 2 to 4 h. At this time, from 75 to 80% of the incorporated radioactivity was contained in phospholipids, about 85% of the esterified rad...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1990-12-01 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::Acetyl-L-carnitine is known as a reservoir of activated acetyl units and as a modulator of metabolic function. The objective of this study was to quantify the fate of the acetyl moiety of acetyl-L-carnitine in lipogenic pathways. Lipogenesis was studied in an adipocyte model, differentiated 3T3-L1 cells, and a hepatom...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1997-07-01 00:00:00
abstract::The recent insight that inflammation contributes to the development of atherosclerosis and type 2 diabetes mellitus constitutes a major breakthrough in understanding the mechanisms underlying these conditions. In addition, it opens the way for new therapeutic approaches that might eventually decrease the prevalence of...
journal_title:Journal of lipid research
pub_type: 杂志文章,评审
doi:10.1194/jlr.R600021-JLR200
更新日期:2007-04-01 00:00:00
abstract::(13)C-Cholesterol was produced with high efficiency by a genetically engineered yeast strain. The method produces ∼ 1 mg of cholesterol per gram of glucose using 100 ml of culture medium. Uniform 94% enrichment where the most abundant product is the fully enriched isotopomer (u-(13)C(27)) is obtained using (u-(13)C(6)...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.D014209
更新日期:2011-05-01 00:00:00
abstract::We describe a method for estimating the total activity of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase (EC 1.1.1.34) in the small intestine of rats. An homogenate of the whole small intestine is prepared rapidly and assayed directly to maximize the yield of enzyme and to minimize opportunity for uncontrolled cha...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1982-02-01 00:00:00
abstract::In the chick, the large cholesteryl ester (CE) store present in the liver during the last period of embryonic life increases at hatching and is rapidly depleted after 2-7 days of postnatal life. In this study we asked whether these changes were associated with variations in the hepatic production of apoB-containing li...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1994-11-01 00:00:00
abstract::Mitochondrial sterol 27-hydroxylase (EC 1.14.13.15) is an important enzyme, not only in the formation of bile acids from cholesterol intermediates in the liver but also in the removal of cholesterol by side chain hydroxylation in extrahepatic tissues. The enzyme has been assayed by complicated methods using radiolabel...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.D200045-JLR200
更新日期:2003-12-01 00:00:00
abstract::The lipids of rat milk, the contents of 9-- 10-day-old rat stomach and intestine, lymph, plasma, and liver were quantitated and their fatty acids were analyzed. Rat milk consists of 97% triacylglycerols, of which 35% of the fatty acids are of medium chain length (C8-C12). However, stomach triacylglycerols show a 25% r...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1981-05-01 00:00:00
abstract::Fatty acids (FA) that are utilized for triglyceride (TG) synthesis in the liver and principally from two sources: FA synthesized de novo in the liver and preformed FA. We have measured the contribution from the two sources to very low density lipoprotein (VLDL) TG synthesis individually for palmitate, oleate, stearate...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1998-06-01 00:00:00
abstract::Rab GTPases require special machinery for protein prenylation, which include Rab escort protein (REP) and Rab geranylgeranyl transferase (RGGT). The current model of Rab geranylgeranylation proposes that REP binds Rab and presents it to RGGT. After geranylgeranylation of Rab C-terminal cysteines, REP delivers the pren...
journal_title:Journal of lipid research
pub_type: 杂志文章,评审
doi:10.1194/jlr.R500017-JLR200
更新日期:2006-03-01 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
abstract::Changes in chromatin structure regulate gene expression and genome maintenance. Molecules that bind to the nucleosome, the complex of DNA and histone proteins, are key modulators of chromatin structure. Previous work indicated that cholesterol, a ubiquitous cellular lipid, may bind to chromatin in vivo, suggesting a p...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M074997
更新日期:2017-05-01 00:00:00