Abstract:
:Clostridium absonum was shown to metabolize primary bile acids to give rise to both 7-oxo bile acids and 7 beta-hydroxy (urso) bile acids. At relatively low redox potential (Eh) values, high yields of urso bile acids were achieved (60-75%). If, however, the Eh value of the culture was allowed to rise above approximately -100 mv, the 7-oxo bile acid would tend to predominate (more than 75%) and the "death phase" was accelerated. Growth of C. absonum in sterile graduated cylinders instead of in conventional Erlenmeyer flasks was effective in delaying the rise in Eh value with time (which appears largely due to diffusion of atmospheric oxygen into the medium) and in preserving a higher viable count of organisms. It is proposed that the formation of excess amounts of 7-oxo bile acid is a manifestation of oxygen toxicity and that it could be mediated by an increasing intracellular NADP:NADPH ratio. Additionally, the reaction: primary bile acid in equilibrium oxo bile acid in equilibrium urso bile acid was shown to be partially reversible. When the organisms were grown with [24-(14)C]chenodeoxycholic, -cholic, or -7-keto-lithocholic acid, this reaction could be clearly demonstrated. The addition of an equimolar concentration of deoxycholic acid (which itself is not metabolized) effectively enhanced the rate of bioconversion of cholate and 7-keto-lithocholic, but not chenodeoxycholate (whose rate of bioconversion was the fastest of the three). When the organisms were grown with urso bile acids (ursocholic or ursodeoxycholic) or with 7-keto-deoxycholic acid, very little metabolism occurred unless deoxycholic acid was added which induced formation of primary and keto bile acids. In all cases, formation of oxo bile acid from primary or urso bile acid occurred as the Eh value of the medium rose with time and could thus be delayed by the use of a cylinder instead of a flask for growing the culture. These results were rationalized by demonstrating that induction of 7 alpha- and 7 beta-hydroxysteroid dehydrogenase is strongly mediated by chenodeoxycholic and deoxycholic acids, weakly mediated by cholic and 7-keto-lithocholic acids, and ineffective with 7-keto-deoxycholic, ursocholic, and ursodeoxycholic acids.
journal_name
J Lipid Resjournal_title
Journal of lipid researchauthors
Sutherland JD,Macdonald IAsubject
Has Abstractpub_date
1982-07-01 00:00:00pages
726-32issue
5eissn
0022-2275issn
1539-7262journal_volume
23pub_type
杂志文章abstract::We have performed plasma lipid profiling using liquid chromatography electrospray ionization tandem mass spectrometry on a population cohort of more than 1,000 individuals. From 10 μl of plasma we were able to acquire comparative measures of 312 lipids across 23 lipid classes and subclasses including sphingolipids, ph...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.P035808
更新日期:2013-10-01 00:00:00
abstract::Fluorescence energy transfer from dehydroergosterol (DHE) to dansylated lecithin (DL) was used to characterize lecithin-cholesterol vesicles in the presence of the bile salt, sodium taurocholate. At lipid concentrations approximating physiological levels, exposure of fluorescently labeled vesicles to the bile salt led...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:2001-06-01 00:00:00
abstract::N-3 trans geometrical isomers of 20:5 n-3 and 22:6 n-3 were isolated from rats fed heated linseed oil. The ability of these acids to inhibit 20:4 n-6 metabolism by human platelets was examined. The concentrations required to inhibit 50% of platelet aggregation (IC50) induced by 2.5 microM 20:4 n-6 were higher for the ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1990-07-01 00:00:00
abstract::Autosomal dominant Stargardt-like macular dystrophy (STGD3) in humans results from mutations in elongation of very long chain FAs-like 4 (ELOVL4), which leads to vision loss in young adults. ELOVL4 is an integral endoplasmic reticulum (ER) protein that mediates the elongation of very long chain (VLC) FAs. Mutations in...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M045443
更新日期:2014-04-01 00:00:00
abstract::Cholelithiasis is a multifactorial process, and several mechanisms have been postulated. A decreased expression of the ileal apical sodium-dependent bile acid transporter (ASBT) and of the cytosolic ileal lipid binding protein (ILBP) was recently described in female non-obese patients. The role of the recently identif...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M800162-JLR200
更新日期:2008-09-01 00:00:00
abstract::Cholesterol 7alpha-hydroxylase, a rate-limiting enzyme for bile acid synthesis, has been implicated in genetic susceptibility to atherosclerosis. The gene, CYP7A1, encoding a protein with this activity, is expressed normally only in hepatocytes and is highly regulated. Our cyp7A1 gene knockout mouse colony, as young a...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M200489-JLR200
更新日期:2003-05-01 00:00:00
abstract::Hyperlipoproteinemia contributes both to kidney disease progression and the development of atherosclerosis. Elevated high density lipoprotein cholesterol and apolipoprotein A-I (apoA-I) serum levels are independent factors protective against the atherosclerotic process. We examined the effects in a transgenic rat mode...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1995-07-01 00:00:00
abstract::The low density lipoprotein receptor (LDLR) regulates the plasma cholesterol level by mediating endocytosis of LDL. We established stable hamster cell lines expressing two LDLRs with distinct functional defects, i.e., endocytosis and ligand binding. In the cell line expressing only I189D h/r (human-rat chimeric) LDLR,...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1999-05-01 00:00:00
abstract::This paper presents a case of typical hyperlipoproteinemia type I in a young woman. Her serum triglycerides varied between 2 and 90 mmol/l and she had substantial amounts of apolipoprotein B-48 in fasting plasma. She had no detectable lipoprotein lipase (LPL) activity in post-heparin plasma (less than 0.2 percent of n...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1990-07-01 00:00:00
abstract::Seven Z-octadecenoic acids having the double bond located in positions 6Z to 13Z were photooxidized. The resulting hydroperoxy-E-octadecenoic acids [HpOME(E)] were resolved by chiral phase-HPLC-MS, and the absolute configurations of the enantiomers were determined by gas chromatographic analysis of diastereoisomeric d...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M018259
更新日期:2011-11-01 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::Baboons possess Lp[a] that is similar to human Lp[a], including the presence of the unique protein, apo[a]. Baboon apo[a] occurred in at least nine isoforms distinguishable by size. Isoforms were resolved by 3-12% polyacrylamide gradient gel electrophoretic separation of serum proteins, and were detected with baboon a...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1989-04-01 00:00:00
abstract::A simple procedure is described for preparing lyso-GM1, a GM1 derivative that lacks the fatty acid moiety, starting from GM1 ganglioside using a one-pot reaction. Ganglioside deacylation was carried out in KOH/propan-1-ol in the absence of oxygen. The yield of lyso-GM1 under optimal conditions (6 h, 90 degrees C, 0.2 ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1992-08-01 00:00:00
abstract::In mice, the yolk sac appears to play a crucial role in nourishing the developing embryo, especially during embryonic days (E) 7;-10. Lipoprotein synthesis and secretion may be essential for this function: embryos lacking apolipoprotein (apo) B or microsomal triglyceride transfer protein (MTP), both of which participa...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1999-11-01 00:00:00
abstract::LY295427, (3 alpha,4 alpha,5 alpha)-4-(2-propenylcholestan-3-ol), acts through an unknown mechanism to derepress the transcription of the low density lipoprotein (LDL) receptor in the presence of 25-hydroxycholesterol (25-OH chol). Preincubation with LY295427 in Chinese hamster ovary (CHO) cells increased uptake of 25...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1996-12-01 00:00:00
abstract::Niemann-Pick type C (NPC) disease is a multisystem disorder resulting from mutations in the NPC1 gene that encodes a protein involved in intracellular cholesterol trafficking. Significant liver dysfunction is frequently seen in patients with this disease. The current studies used npc1 mutant mice to investigate the as...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M600488-JLR200
更新日期:2007-04-01 00:00:00
abstract::Legume consumption appears to lower serum cholesterol and to increase cholesterol saturation of bile, but the mechanisms of these effects have not been established. We studied nine human subjects on a metabolic ward during two randomly ordered 6-7 week periods: one during consumption of a control diet and the other du...
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:1997-06-01 00:00:00
abstract::Recent studies from our laboratory (Yancey, P.G., and R. W. St. Clair. 1992. Arterioscler. Thromb. 12: 1291-1304) have shown that cultured peritoneal macrophages from White Carneau (WC) pigeons clear cholesteryl esters at a slower rate than do macrophages from Show Racer (SR) pigeons (9% per 24 h vs. 42% per 24 h, res...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1994-12-01 00:00:00
abstract::Evidence is given that the heart of the cardiomyopathic UM-X7.1 hamster has a lipid composition different from that of the same tissue isolated from animals of the Syrian hamster parent strain. Also, noncardiac tissues from cardiomyopathic and healthy hamsters exhibit significant compositional differences. On the basi...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:2001-01-01 00:00:00
abstract::A rapid and accurate method is described for the assay of cholesterol ester hydrolase (CEH) activity. Aliquots of the enzyme-substrate incubation mixture are extracted into isopropanol. The free cholesterol concentration in each extract is determined enzymatically using a single aqueous reagent containing cholesterol ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1978-09-01 00:00:00
abstract::Several lipoprotein lipase (LPL) gene polymorphisms have been found associated with fasting lipid levels, but their impact on coronary heart disease (CHD) is less clearly established. We investigated associations of LPL polymorphisms (HindIII, PvuII, Ser447-->Ter) and the newly described mutation Asn291-->Ser with the...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1995-10-01 00:00:00
abstract::In this study, we investigated the hypothesis that regulatory T cells (T(reg)) are involved in the immunomodulatory effects of statins on rheumatoid arthritis (RA) patients. The 12-week study cohort consisted of 55 RA patients and 42 control subjects allocated to either a group treated with atorvastatin (AT) (20 mg/da...
journal_title:Journal of lipid research
pub_type: 杂志文章,随机对照试验
doi:10.1194/jlr.M010876
更新日期:2011-05-01 00:00:00
abstract::Conditions leading to oxidation of LDL in vivo are still unknown. While the occurrence of oxidized lipoproteins and catalytic free iron in advanced atherosclerotic lesions has been demonstrated, the origin of both is unclear. In vivo, iron metabolism is tightly regulated by iron-binding proteins that ensure that virtu...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1999-07-01 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::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::Epoxyeicosatrienoic acids were isolated and purified from female rabbit kidneys. They were identified as a group, prior to resolution, by packed column gas-liquid chromatography-mass spectroscopic techniques as their methyl esters as well as their trimethylsilyl bromohydrin methyl esters. Initial capillary gas-liquid ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1987-07-01 00:00:00
abstract::Bile salts of the coelacanth, Latimeria chalumnae, Smith, have been analyzed and shown to have three bile alcohols, latimerol, 5 alpha-cyprinol, and 5 alpha-cholestane-3 beta, 7 alpha,-12 alpha,25,26-pentol, two C24 bile acids, chenodeoxycholic acid and cholic acid, one C26 bile acid, probably 3 beta, 7 alpha, 12 alph...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1984-12-01 00:00:00
abstract::Cell death-inducing DFF45-like effector b (Cideb), an endoplasmic reticulum (ER)- and lipid droplet (LD)-associated protein, has been shown to play a critical role in maintaining hepatic lipid homeostasis by promoting the lipidation and maturation of VLDL particles. Here, we observed that Cideb is expressed in the jej...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M046482
更新日期:2014-07-01 00:00:00
abstract::Three aliphatic tricarboxylic acids have been found in rat urine. They have been identified as 6-carboxy-5-undecenedioic acid, 6-carboxy-5-dodecenedoic acid, and 6-carboxy-5-tridecenedioic acid. The carbon skeleton structure was determined by mass spectra of the hydrogenated methyl esters. The double bond position was...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1976-11-01 00:00:00
abstract::Phosphorylcholine-1,2-(14)C and choline-1,2-(14)C-labeled cytidine diphosphate choline are incorporated into lecithin by whole homogenates and particulate fractions of rat retina with optimal incorporation of label by the microsomal fraction. The soluble fraction contains a factor(s) which stimulates incorporation of ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1970-11-01 00:00:00