Abstract:
:An in vitro method is presented which measures valid, unidirectional uptake rates for lipids across the intestinal brush border. This method combines analysis by a newly devised, double isotope counting system for solubilized tissue with the use of a nonabsorbable marker to correct gross uptake determinations for contamination by adherent mucosal fluid. Of seven markers, only [(3)H]inulin measured adherent mucosal fluid volumes as much as 20% greater than the other markers. Diffusion of the nonabsorbable marker, as well as of the compound being studied, into the unstirred layer made the time course of uptake critically important. The time lag for diffusion of marker invalidates the use of 1-min incubation periods; however, a linear time course of uptake that intercepts essentially at zero was found for taurocholate and octanoate for periods of from 2 to 5 min. Working within this critical time period with jejunum, it was shown that tissue dry weight was an appropriate measure of the amount of tissue and that uptake rates for taurocholic, octanoic, and lauric acids were linear with respect to concentration. Tissue binding of compounds was not significant. The results demonstrate that careful use of the described method yields accurate measurement of unidirectional uptake rates of lipids across the brush border that are of critical importance in defining the characteristics of membrane penetration and the rate-limiting steps in fat and sterol absorption.
journal_name
J Lipid Resjournal_title
Journal of lipid researchauthors
Sallee VL,Wilson FA,Dietschy JMsubject
Has Abstractpub_date
1972-03-01 00:00:00pages
184-92issue
2eissn
0022-2275issn
1539-7262journal_volume
13pub_type
杂志文章abstract::Solid-phase extraction (SPE) methods are easy, rapid, and reliable. Their growing popularity is in part due to their operational simplicity and cost reduction in solvents, and partly because they are easier to automate. Sphingolipids are implicated in various cellular events such as growth, differentiation, and apopto...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:2000-09-01 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::The ATP binding cassette (ABC) half-transporters ABCG5 and ABCG8 facilitate biliary and intestinal removal of neutral sterols. Here, we identify a binding site for the orphan nuclear receptor liver receptor homolog-1 (LRH-1) at nt 134-142 of the ABCG5/ABCG8 intergenic region necessary for the activity of both the ABCG...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.C400002-JLR200
更新日期:2004-07-01 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::Xanthophyllomyces dendrorhous is a basidiomycete yeast known as a natural producer of astaxanthin, a carotenoid of commercial interest because of its antioxidant properties. Recent studies indicated that X. dendrorhous has a functional SREBP pathway involved in the regulation of isoprenoid compound biosynthesis, which...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.RA119000431
更新日期:2020-02-01 00:00:00
abstract::A group of polyunsaturated fatty acids called conjugated linoleic acids (CLAs) are found in ruminant products, where the most common isomers are cis9, trans11 (c 9,t11) and trans10, cis12 (t10,c12) CLA. A crude mixture of these isomers has been shown in animal studies to alter body composition by a reduction in body f...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M300120-JLR200
更新日期:2003-08-01 00:00:00
abstract::Spontaneously transformed mouse fibroblasts (Balb/c 3T12-3 cells) displayed an increased adhesion when cultured in the presence of 10(-6) M all-trans retinol and acquired morphological characteristics of the normal phenotype. Thus it was of interest to investigate the metabolism of [15-(14)C]retinol in this system. Wi...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1979-03-01 00:00:00
abstract::Agonist-induced lipolysis of adipose fat is robustly inhibited by insulin or by feedback inhibition by the long-chain fatty acids (LCFA) produced during lipolysis. However, the mode of action of LCFA in suppressing adipose lipolysis is not clear. β,β'-Tetramethyl hexadecanedioic acid (Mββ/ EDICA16) is a synthetic LCFA...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M022673
更新日期:2012-05-01 00:00:00
abstract::Isolated etioplasts from 8-day-old dark-grown pea seedlings incorporated [1-(14)C]acetate into lipid at a relatively low rate. Plastids from seedlings that had been illuminated for at least 2 hr showed an enhanced incorporation provided the plastids were illuminated during incubation with the labeled acetate. Dark inc...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1973-11-01 00:00:00
abstract::We have previously shown that expression of a human apoE cDNA in J774 macrophages enhances cholesterol efflux to HDL3. We have also shown that endogenous apoE expression produces a cell surface pool of apoE associated with proteoglycans. In this series of experiments, we first demonstrate the presence of a cell surfac...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1998-02-01 00:00:00
abstract::Mice with a targeted mutation of 3beta-hydroxysterol Delta(7)-reductase (Dhcr7) that cannot convert 7-dehydrocholesterol to cholesterol were used to identify the origin of fetal sterols. Because their heterozygous mothers synthesize cholesterol normally, virtually all sterols found in a Dhcr7 knockout fetus having a D...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M600141-JLR200
更新日期:2006-07-01 00:00:00
abstract::Apolipoprotein C-II (apoC-II) plays a critical role in the metabolism of plasma lipoproteins as an activator for lipoprotein lipase. Human apoC-II consists of 79 amino acid residues (pro-apoC-II). A minor fraction is converted to a mature form by cleavage at the site QQDE releasing the 6 amino-terminal residues. We ha...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1991-11-01 00:00:00
abstract::Previous studies have shown that reduced levels of the adipocyte fatty acid binding protein (FABP)4 (AFABP/aP2), result in metabolic improvement including potentiated insulin sensitivity and attenuated atherosclerosis. Mechanistically, pharmacologic or genetic inhibition of FABP4 in macrophages upregulates UCP2, atten...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M074542
更新日期:2017-07-01 00:00:00
abstract::Diet-induced changes in high density lipoprotein (HDL) density and size were studied in patas monkeys. When the animals were switched from a moderate fat-low cholesterol diet to a high fat-high cholesterol (HFHC) diet, the plasma apoA-I levels increased initially in all of the animals. The apoA-I levels remained eleva...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1984-09-01 00:00:00
abstract::The inbred HcB19 mouse strain expresses a truncated form of thioredoxin interacting protein and is phenotypically characterized by fatty liver and elevated plasma triglycerides and VLDL. Recently, these mice have been proposed as an animal model for familial combined hyperlipidemia. The aim of the present study was id...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M400062-JLR200
更新日期:2004-06-01 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::Inflammatory lipid mediators derived from arachidonic acid (AA) and docosahexaenoic acid (DHA) modify the pathophysiology of brain ischemia. The goal of this work was to investigate the formation of eicosanoids and docosanoids generated from AA and DHA, respectively, during no-flow cerebral ischemia. Rats were subject...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M800200-JLR200
更新日期:2008-09-01 00:00:00
abstract::The subcellular and submitochondrial localization of CTP:phosphatidate cytidylyltransferase is altered in the Morris 7777 hepatoma. Mitochondria in this poorly differentiated tumor are the principal sites of CDP-diacylglycerol synthesis, in contrast to normal rat liver where the endoplasmic reticulum is most active. T...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1978-07-01 00:00:00
abstract::Incubation of 125I-labeled very low density lipoprotein (VLDL) with lipoprotein lipase-rich (postheparin) plasma obtained from intact or supradiaphragmatic rats resulted in the transfer of more than 80% of apoprotein C from VLDL to high density lipoprotein (HDL), whereas apoprotein B was associated with lipoprotein of...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1975-09-01 00:00:00
abstract::Within the cholesterol biosynthesis cascade, the enzyme 2,3-oxidosqualene cyclase [EC 5.4.99.7] is of special interest due to its dual function: cyclization of 2,3-monoepoxysqualene to lanosterol and 2,3;22,23-diepoxysqualene to oxylanosterol. Further determination of the significance of this enzyme for the intracellu...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1996-01-01 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::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::The report that sweat of certain schizophrenics contains the branched chain fatty acid, trans-3-methyl-2-hexenoic acid (TMHA), stimulated an investigation to evaluate the relationship between this fatty acid and schizophrenia. A sensitive and specific gas-liquid chromatography-mass spectroscopic procedure was develope...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1973-07-01 00:00:00
abstract::Elevated serum levels of triglyceride-rich remnant lipoproteins (TRL) are a major risk factor predisposing a subject to atherosclerosis. Apolipoprotein C-III (apoC-III) is a major constituent of TRL that impedes triglyceride hydrolysis and remnant clearance and, as such, may exert pro-atherogenic activities. In the pr...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.m200386-jlr200
更新日期:2002-12-01 00:00:00
abstract::Hormone-sensitive lipase (HSL) catalyzes the rate-limiting step in adipocyte lipolysis. The activity of HSL is thought to be primarily regulated by reversible phosphorylation. However, the regulation of HSL activity by pre-translational mechanisms has been poorly studied. The present studies were undertaken to explore...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1998-08-01 00:00:00
abstract::Mitochondrial cholesterol is maintained within a narrow range to regulate steroid and oxysterol synthesis and to ensure mitochondrial function. Mitochondria acquire cholesterol through several pathways from different cellular pools. Here we have characterized mitochondrial import of endosomal cholesterol using Chinese...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M029942
更新日期:2012-12-01 00:00:00
abstract::In mammals, vitamin A is primarily stored as retinyl esters in hepatic stellate cells under normal dietary intake of the vitamin. Previously, extrahepatic vitamin A-storing stellate cells have only been identified in animals maintained on a vitamin A-rich diet, and it has not been known whether these cells play a role...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1997-04-01 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::A device that lowers a micropipet into position just above a thin-layer plate is described. Use of a self-filling pipet and foot-operated bellows allows one to apply many portions of a sample to the same point at high speed without damaging the adsorbent coating. ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1967-11-01 00:00:00
abstract::Polymorphic transformations in two saturated-unsaturated mixed acid triacylglycerols, SOS (sn -1,3-distearoyl-2-oleoylglycerol) and OSO (sn -1,3-dioleoyl-2-stearoylglycerol), have been studied by FT-IR spectroscopy using deuterated specimens in which stearoyl chains are fully deuterated. A reversible phase transition ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1999-01-01 00:00:00