bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in murine tissue concentrations of dolichol and dolichol derivatives associated with age
Authors: Daniels I. , Hemming F. W. 
Published: November 2006

AbstractThe concentrations of the three major cellular forms of dolichol (free, esterified and phosphorylated) were determined in murine liver, kidney and heart. The tissue levels of these forms of dolichol were studied in detail as a function of age. Changes in the activities of dolichyl phosphate phosphatase and dolichol kinase were also determined. In liver, the concentration of unesterified dolichol, fatty acyl dolichol and dolichyl phosphate increased markedly over a period of 6 to 25 months (four‐fold, 5.5‐fold and nine‐fold, respectively). In kidney only, free dolichol and phosphorylated dolichol increased (approximately four‐fold in each case). However, this tissue consistently showed the highest concentrations of all forms of dolichol as compared to liver and heart. In heart, both free and esterified dolichol concentrations increased (approximately 3.25‐fold in each case); dolichyl phosphate levels were not determined in this tissue. In all tissues studied, the activity of the dolichyl phosphate phosphatase enzyme was considerably higher than that of the dolichol kinase enzyme. In liver, there was no evidence to suggest that either enzyme was critical in determining the relative concentrations of dolichol and dolichyl phosphate. Evidence for such a role for the kinase in the kidney was stronger. Treatment of aging mice with meclofenoxate, a drug that is reported to cause dissolution of lipofuscin, failed to prevent accumulation of dolichol and dolichyl phosphate with age. These observations suggest that not all accumulated dolichol is associated with lipofuscin. Meclofenoxate treatment had no consistent effect on the activities of the enzymes studied.
Caecal and colonic uptake of both linoleic acid and cholesterol in rats following intestinal resection
Authors: Molina M. T. , Ruiz‐Gutierrez V. , Vazquez C. M. , Bolufer J. 
Published: November 2006

AbstractCaecal and colonic uptake of both linoleic acid and cholesterol were studied in rats after distal small bowel resection (DSBR). The results showed that the surgical operation increased the caecal and colonic uptake of linoleic acid. Supplementation with linolenic acid inhibited caecal and colonic uptake of linoleic acid. Experiments carried out in the presence of rotenone and ouabain suggest that facilitated diffusion is the predominant mechanism of caecal and colonic linoleic acid absorption, at least at low concentrations. An increase in caecal and colonic uptake of cholesterol was observed after the surgical operation. The study showed that facilitated diffusion seems to be the mechanism of linoleic acid absorption in the caecum and colon, and that both organ growth and changes in transport function of the epithelial cells of caecum and colon appear to be involved in the adaptive response of the bowel to intestinal resection.
Accumulation of eicosapentaenoic acid in plasma phospholipids of subjects fed canola oil
Authors: Corner Elizabeth J. , Bruce Vivian M. , McDonald Bruce E. 
Published: November 2006

AbstractThe metabolism of α‐linolenic acid from canola oil was studied in eight normolipidemic men. The 42‐day study was divided into three periods: a 6‐day pre‐experimental and two 18‐day experimental. Approximately 75% of the dietary fat (28% of total energy) was provided by a mixture of fats during the pre‐experimental period and either canola oil (CO) or sunflower oil (SO) during the experimental periods. The CO and SO diets were fed in a cross‐over design. The ratios of linoleic to linolenic acid were 2.6∶1 and 73.9∶1 in the CO and SO diets, respectively. Dietary fat source had an effect on plasma phospholipid fatty acids: 18∶1n−9, 18∶3n−3 and 20∶5n−3 were higher (p<0.05), and 18∶2n−6 was lower in the phosphatidylcholine fraction; 18∶1n−9 was higher and 20∶4n−6 lower in the phosphatidyl‐ethanolamine fraction; and 18∶1n−9 and 20∶5n−3 were higher and 20∶4n−6 and 22∶6n−3 were lower in the alkenylacyl‐ethanolamine phospholipid fraction on the CO diet as compared to the SO diet. Consumption of the canola oil diet resulted in higher n−3 fatty acid levels and lower n−6 fatty acid levels in plasma phospholipids than consumption of the sunflower oil diet.
Composition of mouse peritoneal macrophage phospholipid molecular species
Authors: Akoh Casimir C. , Chapkin Robert S. 
Published: November 2006

AbstractThe individual molecular species composition of diacyl, alkylacyl and alkenylacyl glycerophospholipids was determined in mouse peritoneal macrophages. A marked deterogeneity in the relative composition (mol%) of macrophage ether and ester phospholipid individual species was noted. High concentrations of 16∶0–20∶4 were found in ether phospholipids such as alkenylacyl glycerophosphoethanolamine (GPE; 27.5 mol%) and alkylacyl glycerophosphocholine (GPC; 16.6%) as compared to mol % levels of 16∶0–20∶4 in diacyl GPE (5.7%) and diacyl GPC (8.1%), respectively. Interestingly, alkenylacyl GPE was highly enriched in 1‐ether (16∶0) relative to alkylacyl GPC. The predominant diacyl molecular species in glycerophosphoinositol (GPI) and glycerophosphoserine (GPS) were 18∶0–20∶4 (59.1%) and 16∶0–18∶1 (41.1%), respectively. It is noteworthy that the level of 18∶0–20∶4 was several times higher in diacyl GPI (59.1%) than in diacyl GPS (11.1%), diacyl GPE (25.7%), and diacyl GPC (3.7%). The most abundant molecular species in diacyl GPC and diacyl GPE were 16∶0–18∶1 (29.9%) and 18∶0–20∶4 (25.7%), respectively. The abundance of 20∶4 in ether phospholipids, specifically 16∶0–20∶4 and 18∶0–20∶4, in alkylacyl GPC is significant in view of the role these antecedents play in the biosynthesis of platelet‐activating factor (PAF) and 20∶4‐derived eicosanoids in stimulated macrophages. The unique molecular species composition of the peritoneal macrophage distinguishes this cell type from others.
Transformations of 5‐HETE by activated keratinocyte 15‐lipoxygenase and the activation mechanism
Authors: Green Floyd A. 
Published: November 2006

AbstractThere is convincing evidence that normal cultured human keratinocytes possess a 15‐lipoxygenase activity which, however, does not appear to manifest itself without cell membrane damage. When “activated”, this enzyme transforms arachidonic acid into 15‐hydroxyeicosatetraenoic acid (15‐HETE), and linoleic acid into 13‐hydroxyoctadecadienoic acid, presumably by peroxidase action on their respective hydroperoxy intermediates. Normal but notmembrane‐damaged keratinocytes metabolize exogenous 5‐HETE, principally by esterifying the eicosanoid intact, primarily in the triacylglycerol fraction. In the present study, membrane‐damaged keratinocytes were found to transform 5‐HETE to 5,15‐diHETE and also to a lipoxin‐like group of tetraenes. Similar, if not identical, tetraenes were produced by action of the keratinocyte enzyme on 5(S),15(S)‐diHETE, which points to the role of the latter as an intermediate between 5‐HETE and the tetraenes. A direction for further study of the mechanism of the “activation” step is presented.
Molecular species of 1‐O‐alk‐1′‐enyl‐2‐acyl‐, 1‐O‐alkyl‐2‐acyl‐ and 1,2‐diacyl glycerophospholipids in Japanese oysterCrassostrea gigas (Thunberg)
Authors: Yeong Bo Young , Ohshima Toshiaki , Koizumi Chiaki 
Published: November 2006

AbstractMolecular species of 1‐O‐alk‐1′‐enyl‐2‐acyl‐, 1‐O‐alkyl‐2‐acyl‐, and 1,2‐diacyl‐sn‐glycero‐3‐phosphoethanolamine (EPL) andsn‐glycero‐3‐phosphocholine (CPL) of Japanese oysterCrassostrea gigas were analyzed by selectedion monitoring gas chromatography/mass spectrometry using electron impact ionization. The characteristic fragment ions, [RCH=CH+56]+ due to the alkenyl residue in thesn‐1 position and [RCO+74]+ due to the acyl residue in thesn‐2 position of alkenylacylglycerols, [R+130]+ due to the alkyl residue in thesn‐1 position and [RCO+74]+ due to the acyl residue in thesn‐2 position of alkylacylglycerols, [RCO+74]+ due to the acyl residues in thesn‐1 and/orsn‐2 positions of diacylglycerols, and [M−57]+ being indicative of the corresponding molecular weight, were used for structural assignments.For alkenylacyl EPL and CPL, 19 and 16 molecular species were determined, respectively. Two molecular species, 18∶0alkenyl‐22∶6n−3 and 18∶0‐alkenyl‐22∶2‐non‐methylene interrupted diene (NMID), amounted to 53.2% and 47.9%, respectively. The alkylacyl EPL and CPL consisted of 16 and 20 molecular species, respectively, and the prominent components were 18∶0alkyl‐22∶2NMID, 20∶1alkyl‐20∶1n−11 (27.4%) and 20∶1alkyl‐20∶2NMID (16.3%) in the former, and 16∶0alkyl‐20∶5n−3 (23.0%) and 16∶0alkyl‐22∶6n−3 (21.6%) in the latter. For the diacyl EPL and CPL, 14 and 51 molecular species were determined, respectively. The major molecular species were 18∶0–20∶5n−3 (37.4%), 16∶0–20∶5n−3 (14.2%) and 18∶1n−7–22∶2NMID (13.2%) in the former, and 16∶0–20∶5n−3 (33.4%) and 16∶0–22∶6n−3 (22.3%) in the latter. It was found that there were significant differences in the molecular species between the alkylacyl and diacyl EPL and the alkylacyl and diacyl CPL; the number of molecular species was larger in CPL than in EPL, while the number of total carbons and double bonds of the major molecular species were larger in the EPL than in the CPL. Alkenylacyl EPL were similar to alkenylacyl CPL in molecular species composition.
Carbohydrate content of apolipoprotein B‐48 from rat chylomicrons of varying density
Authors: Bochenek Wieslaw J. , Weber Peter , Slowinska Regina , Tang Gexin , Rodgers John B. 
Published: November 2006

AbstractMonosaccharide composition was determined in apolipoprotein B‐48 (apoB) of chylomicrons of rat mesenteric lymph. Chylomicrons were separated into three fractions based on density. Triglyceride and apolipoprotein content were determined in each. ApoB was isolated and quantified using precipitation with isopropanol. Chylomicrons were collected in lymph under normal conditions, and with Poloxalene 2930 when chylomicron secretion was inhibited. Most of the triglyceride was carried in the least dense fraction, while the highest apoB content was in the most dense fraction under normal conditions. Mannose and galactosamine contents of apoB were similar in all fractions while contents of both glucosamine and galactose were highest in the least dense fraction. When chylomicron secretion was inhibited by Poloxalene, the amount of triglyceride recovered in the least dense fraction was significantly reduced. Despite the inhibition of lipid transport in the least dense fraction of chylomicrons by Poloxalene, there was little change in apoB recoveries and in the relative content of various monosaccharides in the apoB from each of the three fractions as compared to results obtained during lipid absorption under normal conditions. In conclusion, carbohydrate composition of apoB of chylomicrons is heterogeneous and varies with chylomicron density.
Occurrence of long and very long polyenoic fatty acids of the n‐9 series in rat spermatozoa
Authors: Aveldaño M. I. , Rotstein N. P. , Vermouth N. T. 
Published: November 2006

AbstractDietary deficiency of essential fatty acids of the n−3 and n−6 series is known to promote a compensatory increase in polyenoic fatty acids of the n−9 series in the lipids of mammalian tissues. In the present study long‐chain n−9 polyenes were found to be normal components of the epididymis and especially of sperm isolated from that tissue, in healthy, well‐fed, fertile rats maintained on essential fatty acid‐sufficient diets. The n−9 polyenes occurred in large concentrations in the choline glycerophospholipids (CGP), the major phospholipid class of spermatozoa in epididymalcauda, and were highly concentrated in plasmenylcholine, the major subclass of CGP. The uncommon polyene 22∶4n−9 was found in the highest proportion, followed in order of relative abundance by 22∶3n−9, 20∶3n−9 and 24∶4n−9. These polyenes were probably derived from oleate (18∶1n−9) in much the same way as long‐chain polyenes of the n−6 and n−3 series are derived from linoleate (18∶2n−6) and linolenate (18∶3n−3), respectively.
Isolation and characterization of novel 2‐hydroxy fatty acids from the phospholipids of the spongeSmenospongia aurea
Authors: Carballelra Néstor M. , Emiliano Anastacio , Rodriguez Jaime , Reyes Elba D. 
Published: November 2006

AbstractThe Caribbean spongeSmenospongia aurea revealed the presence of six novel branched α‐hydroxy fatty acids: 2‐hydroxy‐17‐methyloctadecanoic acid, 2‐hydroxy‐21‐methyldocosanoic acid, 2‐hydroxy‐22‐methyltricosanoic acid, 2‐hydroxy‐22‐methyltetracosanoic acid, 2‐hydroxy‐24‐methylpentacosanoic acid, and 2‐hydroxy‐23‐methylpentacosanoic acid. These novel α‐hydroxy fatty acids were associated with phosphatidylethanolamine. The spongesAplysina lacunosa andAplysina fistularis also contained considerable amounts of α‐hydroxy fatty acids, the very long‐chain 5,9,23‐tricontatrienoic acid (30∶3), and phytanic acid. The sterol composition of the three sponges was also studied. It indicated thatA. lacunosa andA. fistularis contained large amounts of aplysterol and verongulasterol, whileS. aurea did not show any of these sterols. The results are discussed in terms of the taxonomy of the species.
A facile synthesis of 4‐hydroxy‐2(E)‐nonenal
Authors: Gardner H. W. , Bartelt R. J. , Weisleder D. 
Published: November 2006

AbstractA facile, efficient synthesis of 4‐hydroxy‐2(E)‐nonenal is presented as an alternative to the approaches published previously, which either employed four to six separate steps or furnished low yields. The commercially available 3(Z)‐nonenol was sequentially oxidized into 3,4‐epoxynonanol by 3‐chloroperoxybenzoic acid followed by oxidation of the alcohol by periodinane to afford 4‐hydroxy‐2(E)‐nonenal by this two‐step procedure in 48±7% yield.
Omega‐3 fatty acid and cholesterol content of newly hatched chicks from α‐linolenic acid enriched eggs
Authors: Cherian G. , Sim J. S. 
Published: November 2006

AbstractEgg yolk was enriched with α‐linolenic acid (18∶3n−3) by feeding laying hens diets containing flax, canola or soybean seeds. Fertilized eggs were incubated and the fatty acid composition of whole body, liver, plasma, brain and the cholesterol content of plasma and liver tissue of the hatched chicks were studied. Eggs enriched with 18∶2n−6 fatty acids by feeding hens diets containing sunflower seeds were used as the controls. Feeding flax enriched (P<0.05) egg yolk and the developing progeny with 18∶3n−3, 20∶5n−3, 22∶5n−3 and 22∶6n−3. Feeding sunflower seeds resulted in an increase (P<0.05) of 18∶2n−6, 20∶4n−6, 22∶4n−6 and 22∶5n−6. The predominant polyunsaturated fatty acid of the brain was docosahexaenoic acid (22∶6n−3) which was higher (P<0.05) in the flax and canola fed group. The cholesterol content of the liver tissue was lower (P<0.05) in chicks hatched from hens fed flax seeds. This study indicates that 18∶3n−3 and 18∶2n−6 in the maternal diet are potent modulators of long‐chain polyunsaturated n−3 or n−6 fatty acid and of cholesterol content in the developing progeny.
Inhibition of phenytoin bioactivation and teratogenicity by dietary n−3 fatty acids in mice
Authors: Kubow Stan 
Published: November 2006

AbstractEvidence suggests that the teratogenicity of the anticonvulsant drug phenytoin (DPH) can result from its bioactivationvia embryonic prostaglandin synthase and/or maternal cytochromes P450. This study examined whether DPH bioactivation and teratogenicity could be reduced by dietary n−3 fatty acids. Female CD‐1 mice were fed diets containing 2 wt% safflower oil and 10 wt% of either hydrogenated coconut oil, safflower oil, or a cod liver oil/linseed oil mixture (CLO/LO) for three weeks prior to impregnation and throughout gestation. DPH (55 or 65 mg/kg) was administeredvia intraperitoneal injections to pregnant mice at 0900 on gestational days 12 and 13, and on day 19 fetuses were given teratologic assessments. A similar dietary study evaluatedin vivo covalent binding of radiolabeled DPH administered on day 12, and dams were killed 24 h later. A reduction in DPH‐induced cleft palates and a decrease in DPH covalent binding to embryonic protein was observed in the CLO/LO group. Feeding CLO/LO enhanced incorporation of n−3 fatty acids into embryos and inhibited embryonic prostaglandin synthase activity. No differences in maternal hepatic cytochromes P450 activities were observed among dietary treatments. These data indicate that dietary n−3 fatty acids could reduce DPH teratogenicityvia inhibition of embryonic prostaglandin synthase bioactivation of DPH.
Plasma lipids and fatty acids in urbanized Bushmen, Hereros and Kavangos of Southern Africa (Namibia)
Authors: Tichelaar H. Y. , Benadé A. J. S. , O'Keefe S. J. D. , Jooste P. L. , Swanevelder S. A. , Van Staden E. 
Published: November 2006

AbstractThirty‐nine urbanized ethnic Namibian people comprising 21 Bushmen (semi‐urbanized), 7 Hereros and 11 Kavangos were assessed for plasma lipids and fatty acid (FA) composition. Total cholesterol and triacylglycerol concentrations were measured by enzymatic methods, and neutral lipid FA composition by gas‐liquid chromatography. The results demonstrated that while total cholesterol concentrations were not significantly different, significant differences in triacylglycerol concentrations (P<0.05) were seen between Bushmen and Kavangos. By comparing Bushmen with Hereros and Kavangos, significant differences between Bushmen and Kavangos were also observed in plasma triacylglycerol FA compositions, particularly 16∶0 (32.73%vs. 25.05%), 16∶1n−7 (7.00%vs. 5.06%), 18∶2n−6 (9.30%vs. 22.25%) and 20∶3n−6 (0.12%vs. 0.48%), while Kavangos had higher 20∶4n−6 levels than Hereros (1.44%vs. 2.00%). In plasma cholesteryl esters, Bushmen were significantly different from Kavangos in 16∶1n−7 (8.85%vs. 4.93%), 18∶1n−9 (32.06%vs. 23.07%) and 20∶4n−6 (6.91%vs. 10.00%). Significant differences were also observed between Bushmen and Hereros in 18∶0 (1.08%vs. 1.29%) and 18∶2n−6 (35.68%vs. 45.50%). The FA of Namibian groups were also compared with South African reference groups comprising urbanized whites and Xhosas and rural Vendas. The differences in blood lipid values can be explained primarily by excessive alcohol consumption. These results suggest that semi‐urbanized Bushmen have changed their diets under urbanized conditions which may increase their risk of coronary heart disease.
The gastrointestinal handling and metabolism of [1‐13C]palmitic acid in healthy women
Authors: Murphy Jane L. , Jones Amanda , Brookes Steven , Wootton Stephen A. 
Published: November 2006

AbstractThe gastrointestinal handling and metabolism of [1‐13C]palmitic acid given as the free fatty acid was examined in six healthy women by measuring the excretion of13C‐label in stool and in breath as13CO2. The gastrointestinal handling of [1‐13C]palmitic acid was compared with the apparent absorption of dietary lipid by measuring lipid losses in stool. The variation both within and between subjects was determined by repeating the study in the same individuals on separate occasions. The time course for excretion of label in stool over the five‐day study period followed a common pattern, with most of the label excreted over the first two days of the stool collection.13C‐Label excreted in stool over the five‐day study period was 14.3±9.8% of that administered and on repeating the trial was 31.6±24.7% (not significantly different due to variability); there was poor agreement within subjects. Lipid excreted in stool expressed as a percentage of ingested lipid was 5.2±4.4% in Trial 1 and 5.9±4.0% in Trial 2, and was the same in each individual on repeating the trial. There was no clear relationship between the excretion of13C‐label and lipid in stool (Trial 1:R=−0.43,P>0.40; Trial 2:R=−0.02,P>0.97). On the first occasion, 22.0±4.5% of the administered label was excreted on breath over the 15‐h study period and on repeating the trial was 15.8±9.5% (not significantly different) with poor repeatability in a given individual. There was an inverse relationship between the proportion of13C‐label excreted in stool and that excreted on breath in Trial 1 (R=−0.80,P>0.06) with a weaker association observed in Trial 2 (R=−0.49,P>0.32). Correcting for differences in the apparent absorption of label reduced the variability in its excretion in breath observed between subjects, particularly in Trial 2. It is concluded that although there are differences in the gastrointestinal handling of [1‐13C]palmitic acid both within and between healthy adults, the postprandial oxidation of absorbed substrate was similar. The assumptions underlying these observations need to be examined by characterizing the nature of13C‐label in stool.
Dietary fat alters the distribution of cholesterol between vesicles and micelles in hamster bile
Authors: Cohen Bertram I. , Mikami Takahiro , Ayyad Nariman , Mikami Yasuko , Mosbach Erwin H. 
Published: November 2006

AbstractThe type of dietary fat strongly affects the incidence of gallstones in the hamster model of cholesterol cholelithiasis. The present study was designed to determine whether dietary fats could affect gallstone formation by altering the microstructure (vesicular/micellar ratio) of cholesterol in bile. Golden Syrian hamsters from Sasco (Omaha, NE) or Charles River (Wilmington, MA) were fed nutritionally adequate semipurified diets to which were added: (i) 4.0% butterfat without added cholesterol; (ii) 1.2% palmitic acid plus 0.3% cholesterol; or (iii) 4.0% safflower oil plus 0.3% cholesterol. Gallstone incidence and the percentage of cholesterol in vesicles and micelles were determined after two‐ or six‐week feeding periods. Three out of ten Sasco hamsters fed the 1.2% palmitic acid diet for two weeks had cholesterol stones, while none of the eight Charles River animals had stones. In the Sasco hamsters, a significant proportion of the biliary cholesterol was found in void volume vesicles (28.8%) and small vesicles (17.1%); Charles River hamsters had negligible proportions (1.1%) of cholesterol in void volume vesicles and 15.4% in small vesicles. Cholesterol gallstones were most abundant in Sasco hamsters fed 1.2% palmitic acid for six weeks (nine out of ten animals); the mean cholesterol saturation index of the bile was 1.27. A significant proportion of the biliary cholesterol was eluted in the void volume vesicles (21.4%) and in small vesicles (15.0%). Five of the eight identically treated Charles River hamsters had cholesterol stones; the cholesterol saturation index averaged 1.36, and the biliary cholesterol was present in void volume vesicles (31.3%) and small vesicles (14.3%). Vesicles were not detected in the bile of hamsters fed cholesterol‐free diets, and none of these animals developed cholesterol gallstones. Safflower oil diets inhibited stone formation even though the cholesterol saturation index was above unity. After six weeks, biliary cholesterol transported in void volume vesicles was highest for Sasco hamsters (13.3%) as compared to Charles River animals (6.9%), but total cholesterol transported in void volume vesicles plus small vesicles was similar in both groups (33.5% vs. 26.2%), respectively. These results suggest that in both strains of hamsters dietary fat influences gallstone formation by modulating the vesicular/micellar distribution of biliary cholesterol. Apparently, the presence of cholesterol/phospholipid vesicles in bile is associated with cholesterol gallstone formation.