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 twofold in beta-sitosterol compared to membranes from animals fed the coconut oil diet alone. Acylcoenzyme A:cholesterol acyltransferase (ACAT) activity in jejunum and ileum was decreased significantly in animals fed the plant sterol alone. In membranes from animals fed 1% beta-sitosterol and 1% cholesterol, beta-sitosterol content increased 50% whereas cholesterol was modestly decreased compared to their controls fed only cholesterol. Intestinal ACAT was unchanged in the animals fed both sterols when compared to their controls. beta-Sitosterol esterification was determined by incubating intestinal microsomal membranes with either [(14)C]beta-sitosterol-albumin emulsion or [(14)C]beta-sitosterol:dipalmitoyl phosphatidylcholine (DPPC) liposomes to radiolabel the endogenous sterol pool. Oleoyl-CoA was then added. The CoA-dependent esterification rate of beta-sitosterol was very slow compared to that of cholesterol using both techniques. An increased amount of endogenous microsomal beta-sitosterol, which occurs in animals fed 1% beta-sitosterol, did not interfere with the stimulation of ACAT activity secondary to cholesterol enrichment of the membranes. Enriching microsomal membranes three- to five-fold with beta-sitosterol did not affect ACAT activity. Freshly isolated intestinal cells were incubated for 1 hour with [(3)H]oleic acid and beta-sitosterol:DPPC or 25-hydroxycholesterol:DPPC. Incorporation of oleic acid into cholesteryl esters did not change in the presence of beta-sitosterol but increased fourfold after the addition of 25-hydroxycholesterol. We conclude that the CoA-dependent esterification rate of cholesterol is at least 60 times greater than that of beta-sitosterol. Membrane beta-sitosterol does not interfere with nor compete with cholesterol esterification. Inadequate esterification of this plant sterol may play a role in the poor absorption of beta-sitosterol by the gut.-Field, F. J., and S. N. Mathur. beta-Sitosterol: esterification by intestinal acylcoenzyme A:cholesterol acyltransferase (ACAT) and its effect on cholesterol esterification.
journal_name
J Lipid Resjournal_title
Journal of lipid researchauthors
Field FJ,Mathur SNsubject
Has Abstractpub_date
1983-04-01 00:00:00pages
409-17issue
4eissn
0022-2275issn
1539-7262journal_volume
24pub_type
杂志文章abstract::Ursodeoxycholic acid (UDCA, ursodiol) is used to prevent damage to the liver in patients with primary biliary cirrhosis. The drug also prevents the progression of colorectal cancer and the recurrence of high-grade colonic dysplasia. However, the molecular mechanism by which UDCA elicits its beneficial effects is not e...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M021733
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journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.P023994
更新日期:2012-05-01 00:00:00
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journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1982-01-01 00:00:00
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journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1999-01-01 00:00:00
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journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M092486
更新日期:2019-09-01 00:00:00
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journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1990-02-01 00:00:00
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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
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journal_title:Journal of lipid research
pub_type: 杂志文章,随机对照试验
doi:10.1194/jlr.P093013
更新日期:2019-06-01 00:00:00
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-VLD...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1993-04-01 00:00:00
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journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1986-11-01 00:00:00
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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::Enzymes associated with glycerolipid biosynthesis were examined in microsomal fractions of liver and adipose tissue obtained from swine of various ages. Generally, liver glycerophosphate acyltransferase, phosphatidate phosphohydrolase, diglyceride acyltransferase, and choline phosphotransferase activities were substan...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1979-02-01 00:00:00
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journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1999-05-01 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
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journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1967-01-01 00:00:00
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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
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journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1967-05-01 00:00:00
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journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M700406-JLR200
更新日期:2008-01-01 00:00:00
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journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1996-06-01 00:00:00
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journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1998-08-01 00:00:00
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journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1984-05-01 00:00:00
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journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1986-07-01 00:00:00
abstract::The lipase superfamily includes three vertebrate and three invertebrate (dipteran) proteins that show significant amino acid sequence similarity to one another. The vertebrate proteins are lipoprotein lipase (LPL), hepatic lipase (HL), and pancreatic lipase (PL). The dipteran proteins are Drosophila yolk proteins 1, 2...
journal_title:Journal of lipid research
pub_type: 杂志文章,评审
doi:
更新日期:1992-02-01 00:00:00
abstract::HDL cholesterol levels are decreased in Crohn's disease, a tumor necrosis factor-alpha (TNF-alpha)-driven chronic inflammatory condition involving the gastrointestinal tract. ATP-binding cassette transporter A1 (ABCA1), one of several liver X receptor (LXR) target genes, is a cell surface transporter that mediates the...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M002410
更新日期:2010-06-01 00:00:00
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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
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journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M500209-JLR200
更新日期:2006-02-01 00:00:00
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journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.D071068
更新日期:2016-11-01 00:00:00
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journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1991-06-01 00:00:00
abstract::In contrast to current methods of bile acid analysis that require the separation of bile acids into different groups prior to their analysis, the HPLC method using a reverse phase column and gradient elution that we developed permits the separation and detection of nonconjugated, glycine-conjugated, and esterified bil...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1997-09-01 00:00:00
abstract::The ability to exogenously present cell-surface receptors in high-affinity conformations in a synthetic system offers an opportunity to provide host cells with protection from pathogenic toxins. This strategy requires improvement of the synthetic receptor binding affinity against its native counterpart, particularly w...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M007401
更新日期:2010-09-01 00:00:00