Abstract:
:The in vivo formation of the sulfate ester of glycolithocholate is a critical step in the elimination of this hepatotoxic bile salt. Rhesus monkeys fed chenodeoxycholate or ursodeoxycholate, the precursors of lithocholate, develop frank cirrhosis in association with accumulation of nonsulfated glycolithocholate in bile. An enzyme catalyzing the formation of glycolithocholate-3-sulfate has been isolated from hepatic cytosol of adult female rhesus monkeys and has been purified 146-fold. When reduced it appears as a 30 kD band on an SDS-polyacrylamide gradient gel. It has a pH optimum of 7.0 and is stimulated by low concentrations of Mg2+ (up to 2 mM), but does not have an absolute requirement for this metal ion. The kinetics of this enzyme have been investigated to ascertain whether its reaction mechanism can account for the poor in vivo rate of glycolithocholate sulfation. Inhibitor studies with an oxidized metabolite of lithocholate, 3-keto-5 beta-cholanoate, showed that the latter is a competitive inhibitor of glycolithocholate and is noncompetitive with the active form of sulfate, 3'phosphoadenosine-5'-phosphosulfate. The monophosphonucleotide 3'-AMP is a competitive inhibitor of 3'phosphoadenosine-5'-phosphosulfate, and is noncompetitive with glycolithocholate. These observations are consistent with a sequentially ordered Bi Bi reaction mechanism in which the bile salt is the first substrate to bind to the enzyme. Such a reaction mechanism for bile salt:3'phosphoadenosine-5'-phosphosulfate:sulfotransferase would be, therefore, the first time in which the sulfate acceptor (the bile salt) is the initial substrate to bind to a sulfotransferase. These studies have shown that although rhesus monkeys have a liver enzyme capable of forming the sulfate ester of glycolithocholate, its reaction mechanism and the potent inhibition caused by simple metabolites, such as 3-keto-5 beta-cholanoate, may serve to under-express the activity of the enzyme in vivo.
journal_name
J Lipid Resjournal_title
Journal of lipid researchauthors
Barnes S,Waldrop R,Crenshaw J,King RJ,Taylor KBsubject
Has Abstractpub_date
1986-11-01 00:00:00pages
1111-23issue
11eissn
0022-2275issn
1539-7262journal_volume
27pub_type
杂志文章abstract::The biosynthesis of prostaglandins by isolated rat adrenocortical cells has been studied by determinations of products formed during incubations with labeled arachidonic acid and by radioimmunoassays. Analysis by thin-layer chromatographic separation of silicic acid column fractions indicated that PGE2, PGA2, (B2) and...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1979-01-01 00:00:00
abstract::Lipoproteins internalized by the LDL receptor (LDLR) are released from this receptor in endosomes through a process that involves acid-dependent conformational changes in the receptor ectodomain. How acidic pH promotes this release process is not well understood. Here, we assessed roles for six histidine residues for ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M070938
更新日期:2017-02-01 00:00:00
abstract::Vitamin A (VA) is stored in tissues predominantly as retinyl esters (REs), which provide substrate for the production of bioactive retinoids. Retinoic acid (RA), a principal metabolite, has been shown to induce postnatal lung development. To better understand lung RE storage, we compared VA (given as retinyl palmitate...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M600061-JLR200
更新日期:2006-08-01 00:00:00
abstract::HMG-CoA reductase inhibitors (statins) are effective lipid-altering drugs for the treatment of dyslipidemia in patients with type 2 diabetes mellitus. We conducted a randomized, double-blind, placebo-controlled, crossover design trial to determine the effects of simvastatin, 80 mg/day, on plasma lipid and lipoprotein ...
journal_title:Journal of lipid research
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1194/jlr.M500335-JLR200
更新日期:2005-12-01 00:00:00
abstract::Hypertriglyceridemia results from accumulation of triglyceride (TG)-rich lipoproteins (TRLs) in the circulation and is associated with increased CVD risk. ApoC-III is an apolipoprotein on TRLs and a prominent negative regulator of TG catabolism. We recently established that in vivo apoC-III predominantly inhibits LDL ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M093740
更新日期:2019-08-01 00:00:00
abstract::Ceramides containing phytosphingosine as base and one of the fatty acids 16:0, 18:0, 20:0, 22:0, 23:0, and 24:0, were prepared by direct coupling in the presence of a mixed carbodiimide. The ceramides were analyzed as the 1,3,4-tri-O-trimethylsilyl ether derivatives by gas-liquid chromatography-mass spectrometry. Gas ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1970-05-01 00:00:00
abstract::A simplified method for the preparation of the Dittmer-Lester spray for the detection of phospholipids on thin-layer chromatograms is described. ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1968-05-01 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::Imidazole catalyzed acylations of lysolipids by acyl-CoAs in water at room temperature and at a pH close to neutrality. In the presence of oleoyl-CoA and either lysophosphatidylcholine, 1-palmitoyl-sn-glycero-3-phosphocholine (LPC); lysophosphatidylglycerol, monoacyl-sn-glycero-3-phosphoglycerol; lysophosphatidyl acid...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.m200075-jlr200
更新日期:2002-07-01 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::Polyunsaturated fatty acids, including docosahexaenoic acid (DHA, 22:6n-3), modulate immune responses and exert beneficial immunosuppressive effects, but the molecular mechanisms inhibiting T-cell activation are not yet elucidated. Lipid rafts have been shown to play an important role in the compartmentalization and m...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M500033-JLR200
更新日期:2005-09-01 00:00:00
abstract::Human lysosomal acid lipase/cholesteryl ester hydrolase (hLAL) is essential for the intralysosomal metabolism of cholesteryl esters and triglycerides taken up by receptor-mediated endocytosis of lipoprotein particles. The key role of the enzyme in intracellular lipid homeostasis is illustrated by two lysosomal storage...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1999-02-01 00:00:00
abstract::The two oxysterols, 27-hydroxycholesterol (27OH) and 24S-hydroxycholesterol (24OH), are both inhibitors of cholesterol synthesis and activators of the liver X receptor (LXR) in vitro. Their role as physiological regulators under in vivo conditions is controversial, however. In the present work, we utilized a previousl...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M034124
更新日期:2013-04-01 00:00:00
abstract::Biliary cholesterol secretion is ordinarily tightly coupled to phosphatidylcholine (PC) secretion. Bile PCs are distinct in composition and predominantly composed of molecular species with 16:0 in the sn-1 position and 18:2 and 18:1 in the sn-2 position. In an attempt to acutely change the composition of biliary PCs a...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1991-06-01 00:00:00
abstract::The role of very low density lipoproteins (VLDL) in the energy metabolism of conscious, 24-hr fasted rats was studied. VLDL labeled with [2-3H]glycerol and [1-14C]palmitate were infused into the rats, along with [1-13C]palmitate bound to albumin and d-8-glycerol, and various metabolic factors were assessed. The rates ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1985-02-01 00:00:00
abstract::Bile acids are a group of molecular species of acidic steroids with peculiar physical-chemical and biological characteristics. At high concentrations they become toxic to mammalian cells, and their presence is pertinent in the pathogenesis of several liver diseases and colon cancer. Bile acid cytoxicity has been relat...
journal_title:Journal of lipid research
pub_type: 杂志文章,评审
doi:10.1194/jlr.R900011-JLR200
更新日期:2009-09-01 00:00:00
abstract::A study was conducted to determine the levels of cellular retinol-binding protein (CRBP) mRNA and protein in various tissues of the rat, to explore relationship between CRBP mRNA and protein levels in different tissues, and to examine the effects of changes in retinol nutritional status on the tissue distribution and ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1990-05-01 00:00:00
abstract::The mixed dyslipidemia phenotype is characterized by elevated triglycerides (TG), low HDL cholesterol (HDL-C), increased ApoB levels, and premature coronary atherosclerosis. Fibrate-statin combination therapy reduces ApoB levels and coronary events in the mixed dyslipidemia population. We sought to identify gene-gene ...
journal_title:Journal of lipid research
pub_type: 杂志文章,随机对照试验
doi:10.1194/jlr.M028829
更新日期:2012-11-01 00:00:00
abstract::Lymph fistula rats with either biliary fistula or pancreaticobiliary fistula were used to measure coenzyme A-independent mucosal cholesterol esterifying activity in the presence and absence of pancreatic exocrine secretion. Efficiency of pancreatic diversion was verified to minimize contamination of mucosal homogenate...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1981-01-01 00:00:00
abstract::The regulation of hepatic and intestinal 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase and acyl-CoA; cholesterol acyltransferase (ACAT) activities by dietary fish oil was examined in the rabbit. Rabbits were fed 10% menhaden oil or menhaden oil plus 1% cholesterol for 14 days. They were compared with animals fed ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1987-01-01 00:00:00
abstract::The behavior of human omental fat cells in vitro has been examined in order to define conditions under which glucose is converted to glyceride-glycerol and glyceride fatty acids. Synthesis of glyceride fatty acids from glucose reached maximal rates only after several hours of incubation in Krebs-Henseleit bicarbonate ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1969-05-01 00:00:00
abstract::The effect of various levels of the oral contraceptive drug, Enovid E, on serum and liver lipid levels of adult female rats has been investigated. Doses ranging from 0.052 to 1.04 mg/day have been employed in rats fed control or cholesterol-containing diets. It has been confirmed that after administration of even low,...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1971-05-01 00:00:00
abstract::The total nitrogen and L-hydroxyproline concentrations of two intra-abdominal and two subcutaneous sites of adipose tissue were measured in male and female Wistar rats. At 100 g body weight the nitrogen concentration of intra-abdominal adipose tissue was slightly lower than that of subcutaneous adipose tissue. As age ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1970-07-01 00:00:00
abstract::Sphingoglycolipids (SGLs) are cell membrane constituents. As the ceramide structure influences the biological properties of the SGL, we characterized by electrospray ionization tandem mass spectrometry the molecular species of ceramides present in SGL of mouse brain. We report here for the first time the presence in m...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:10.1194/jlr.M300331-JLR200
更新日期:2004-02-01 00:00:00
abstract::Liver cells isolated from normal and cholestyramine-treated rats were incubated as cell suspensions for up to 4 hr in a simple, defined medium. The bile acid concentration in cells plus cell medium was determined by gas-liquid chromatography. Normal hepatocytes synthesized cholic acid at an initial rate of 0.25 nmol/m...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1979-09-01 00:00:00
abstract::The hydrolysis of HDL phospholipids (PL) and glycerides by hepatic lipase (HL) has been investigated in native and reconstituted HDL particles (Lp2A-I). Fasting, normolipidemic HDL exhibit total lipid hydrolytic rates of between 10 and 36 nM FA/h per microM PL. Of the total fatty acids liberated with HDL3 only 1% are ...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1997-11-01 00:00:00
abstract::Biliary secretion of bile acid glucuronides was studied in control rats and in rats with a congenital defect in hepatobiliary transport of organic anions (GY rats). In control animals, hepatobiliary transport of [3H]lithocholic acid 3-O-glucuronide and [3H]cholic acid 3-O-glucuronide was efficient (greater than 95% in...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1989-12-01 00:00:00
abstract::In a previous study, it was shown that the peroxisomal fraction of rat liver, isolated by Percoll gradient centrifugation of a light mitochondrial fraction, was able to catalyze conversion of 3 alpha, 7 alpha, 12 alpha-trihydroxy-5 beta-cholestanoic acid (THCA) into cholic acid (Pedersen, J. I., and J. Gustafsson, 198...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1983-12-01 00:00:00
abstract::We report the characterization of eight mutations of sterol 27-hydroxylase gene (CYP27) in five Italian patients with cerebrotendinous xanthomatosis, who were found to be compound heterozygotes. Four mutations (C --> T at nt 45 of exon 4, G(+1) --> A in intron 6, G(+5) --> T in intron 7, and G(-1) --> A in intron 7) a...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:1997-11-01 00:00:00
abstract::Potentially atherogenic triglyceride-rich lipoprotein (TRL) remnants can be isolated and quantitated as remnant-like particles (RLP), using an immunoaffinity gel containing specific anti-human apolipoprotein A-I (apoA-I) and apoB-100 monoclonal antibodies. The aim of the present study was to determine the relationship...
journal_title:Journal of lipid research
pub_type: 杂志文章
doi:
更新日期:2000-09-01 00:00:00