bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alteration in mouse splenic phospholipid fatty acid composition and lymphoid cell populations by dietary fat
Authors: Huang Shu‐Cai , Fritsche Kevin L. 
Published: November 2006

AbstractThe fatty acid composition of diacyl‐ and alkylacylglycerophosphocholine (PC), phosphatidylinositol (PI), phosphatidylserine (PS), alkenylacyl‐glycerophosphoethanolamine (aPE), and diacyl‐ and alkylacyl‐glycerophosphoethanolamine (dPE) was assessed in isolated splenocytes from C3H/Hen mice fed one of four purified isocaloric diets for six weeks. Diets contained 20% by weight of either a high‐linoleate sunflower oil (Hi 18∶2), a high‐oleate sunflower oil (Hi 18∶1), a mixture of 17% menhaden fish oil and 3% high‐linoleate sunflower oil (Hi n−3), or a mixture of 17% coconut oil and 3% high‐linoleate sunflower oil (Hi SFA). Spleen weight and immune cell yield were significantly higher (P<0.05) in mice fed the Hi 18∶1 or the Hi n−3 diets compared with those fed the Hi 18∶2 and Hi SFA diets. Distinctive patterns of fatty acids were observed for each phospholipid in response to dietary fatty acids. Dietary fat significantly affected (P<0.05) total polyunsaturated fatty acids (PUFA) in PC and dPE, total saturated fatty acids (SFA) in PC, total monounsaturated fatty acids (MUFA), and n−3 PUFA in all phospholipid classes examined. In mice fed the Hi n−3 diet, n−3 PUFA were significantly elevated, whereas n−6 PUFA decreased in all of the phospholipids. In these mice, eicosapentaenoic acid (EPA) was the predominant n−3 PUFA in PC and PI, whereas docosahexaenoic acid (DHA) was the major n−3 PUFA in aPE and PS. Interestingly, the ratios of n−3/n−6 PUFA in the phospholipids from these mice were 3.2, 2.4, 1.8, 0.8 and 0.8 for aPE, PS, dPE, PC and PI, respectively. These data suggest a preferential incorporation of n−3 PUFA into aPE, PS and dPE over PC and PI.
Comparative uptake of α‐ and γ‐tocopherol by human endothelial cells
Authors: Tran Khai , Chan Alvin C. 
Published: November 2006

AbstractThe intake of γ‐tocopherol by North Americans is generally higher than that of α‐tocopherol. However, the levels of α‐tocopherol in human blood have consistently been shown to be higher than those of γ‐tocopherol suggesting differential cellular retention of the two tocopherol forms. We sought to resolve this question by studying tocopherol metabolism by human endothelial cells in culture. The time‐ and dose‐dependent uptake of γ‐tocopherol by endothelial cells was similar to that of α‐tocopherol. To determine the comparative uptake between α‐ and γ‐tocopherol, we adopted two approaches in which cells were enriched with either increasing concentrations of an equimolar mixture of α‐ and γ‐tocopherol; or cells were enriched with a fixed concentration of tocopherols in which the α to γ ratio was varied. Our results indicated that there was a preferential uptake of γ‐tocopherol by the cells. When cells were enriched with either α‐ or γ‐tocopherol and the disappearance of individual tocopherols was monitored over time, γ‐tocopherol exhibited a faster rate of disappearance. The faster turnover of γ‐tocopherol can explain the discrepancy between high intake and low retention of γ‐tocopherol in man.
The quantitation of long‐chain acyl‐CoA in mammalian tissue
Authors: Tardi Paul G. , Mukherjee Jagat J. , Choy Patrick C. 
Published: November 2006

AbstractIntracellular long‐chain acyl‐CoA esters are key metabolites in lipid metabolism. A rapid procedure was developed for the isolation of long‐chain acyl‐CoA from mammalian tissues. Acyl‐CoA was extracted from the tissue with chloroform/methanol and separated from other lipid‐containing metabolites by phase partition with solvents. The content and the molecular species of acyl‐CoA were determined by gas‐liquid chromatography. In rat liver and hamster heart, the total acyl‐CoA content was estimated to be 83±11 and 61±9 nmol/g wet weight, respectively. The results obtained are comparable to those reported in previous studies. The relative ease of this procedure would permit the determination of acyl‐CoA contents in a large number of samples.
Incorporation of cyclic fatty acid monomers in lipids of rat heart cell cultures
Authors: Ribot E. , Grandgirard A. , Sébédio J. L. , Grynberg A. , Athias P. 
Published: November 2006

AbstractPrimary cultures of newborn rat cardiomyocytes were grown in medium supplemented with cyclic fatty acid monomers (CFAM) which had been isolated from heated linseed oil. The cells were harvested, and lipids were extracted and fractionated using silica cartridges and high‐performance liquid chromatography. The CFAM structures isolated from cellular lipids were determined and compared to those that had been supplemented to the medium, using gas‐liquid chromatography coupled with mass spectrometry (GC/MS). We found that CFAM were incorporated into phospholipids and neutral lipids of cardiomyocytes. Furthermore, CFAM with a cyclopentyl ring structure were more abundant in cardiomyocytes than were the cyclohexyl ring isomers. Our data suggest that CFAM of the 5‐carbon and 6‐carbon ring series are metabolized differently in newborn rat cardimyocytes.
Gamma linolenic acid (GLA) content of encapsulated evening primrose oil products
Authors: Gibson Robert A. , Lines David R. , Neumann Mark A. 
Published: November 2006

AbstractThe fatty acid composition of 16 brands of evening primrose oil (EPO) capsules was determined by capillary gas chromatography. Fourteen of these EPO brands contained γ‐linolenic acid (GLA) levels between 7% and 10% (mean, 8.7; range, 1.9–10.5%) and there was generally good agreement between the level of GLA claimed by the manufacturer and the level determined by analysis. Low levels of the monoenes 22∶1 and 24∶1 found in some brands may indicate contamination of EPO with borage oil.
Dietary arachidonic and linoleic acids: Comparative effects on tissue lipids
Authors: Whelan J. , Broughton K. S. , Surette M. E. , Kinsella J. E. 
Published: November 2006

AbstractThe effects of preformed dietary arachidonic acid (AA, 20∶4n−6) on murine phospholipid fatty acid composition in tissues capable (liver) and incapable (peritoneal exudate cells, PEC) of desaturating and elongating linoleic acid (LA, 18∶2n−6) to AA were investigated. The results were compared with those obtained on matched animals on LA diets by either substituting or supplementing dietary LA with AA. Modest amounts of AA ethyl ester (0.5 wt%) included in the diet significantly increased tissue phospholipid AA levels by 39% and 57% in the liver and in PEC, respectively. The changes were further enhanced when dietary LA and AA intakes were equivalent,i.e., 57% and 68% in liver and PEC, respectively. This enrichment was observed in all phospholipid classes analyzed, with the greatest impact on phosphatidylcholine. In addition, the doubling of dietary LA had little effect on tissue phospholipid AA levels. The data suggest that while the level of n−6 PUFA may have an important effect on tissue fatty acid composition, the type of n−6 PUFA in the diet could be of greater significance.
Agonist‐induced lipoxin A4 generation: Detection by a novel lipoxin A4‐ELISA
Authors: Levy Bruce D. , Bertram Sherry , Tai H. H. , Israel Elliot , Fischer Andrew , Drazen Jeffrey M. , Serhan Charles N. 
Published: November 2006

AbstractLipoxin A4 (LXA4) possesses potent bioactions. To facilitate its detection, an enzyme‐linked immunosorbent assay (ELISA) was developed that proved sensitive and selective. Quantitation by ELISA of LXA4 generated from cellular sources strongly correlated (r=0.99) with values obtained by high‐pressure liquid chromatography (HPLC). We used this LXA4‐ELISA to examine parameters influencing LXA4 generation from endogenous substrates during human platelet‐neutrophil (PLT‐PMN) interactionsin vitro. Agonist‐induced LXA4 production was clearly evident at a PLT‐PMN ratio of 10∶1, and recombinant human granulocyte/monocyte colony stimulating factor‐priming of PMN augmented LXA4 generation 5–6 fold. The chemotactic peptide formylmethionyl‐leucyl‐phenylalanine, platelet‐derived growth factor and arachidonic acid (20∶4n−6) each stimulated formation of immunoreactive LXA4 (iLXA4) in these co‐incubations. The presence of iLXA4 was also evaluatedin vivo in aspirin‐sensitive asthmatic patients who, in a randomized, double‐blind crossover design, underwent nasal lavage after they each ingested a predetermined threshold dose of aspirin or placebo. Aspirin challenge provoked statistically significant increases in iLXA4 in each patient (P<0.005). These results validate the use of a solid‐phase ELISA for detection of LXA4. Furthermore, the use of this ELISA has allowed the first documentation of iLXA4 formation in human subjects with aspirin‐sensitive asthma following specific antigenic challenge.
Triacylglycerol assembly from binary mixtures of fatty acids byApiotrichum curvatum
Authors: Lee Inmok , Hammond Earl G. , Cornette James L. , Glatz Bonita A. 
Published: November 2006

AbstractTo observe how the stereospecific distribution of acyl groups in triglycerides is affected by the composition of fatty acids available for esterification, the oleaginous yeastApiotrichum curvatum was grown on various binary mixture of palmitic, stearic, oleic and linoleic acids as carbon sources, and the yeast triglycerides were analyzed. When oleic acid‐linoleic acid mixtures in various ratios were used as substrates, the yeast grew well, and the composition of the intracellular triglycerides reflected the substrate composition, but more linoleate than oleate was deposited in the triglycerides. Oleate was favored over linoleate at thesn‐2 position of the glycerol. With substrates containing palmitic and stearic acids, the yeast accumulated less oil, and incorporation of stearic acid into the triglycerides also was very limited. When mixtures of palmitic acid‐oleic acid and palmitic acid‐linoleic acid were used as substrates, the yeast triglyceride composition did not reflect that of the substrate, and the accumulation in the yeast of the unsaturated acid in the substrate was favored. Possibly, the yeast had more limited access to solid than to liquid substrates. For oleic acid‐linoleic acid substrates, when the percentages of oleate and linoleate at the three glycerol positions were plottedvs. the percentage of these acyl groups in the total triglyceride, apparent linear relations were observed for most of the range, and the sums of the intercepts and slopes of the three lines for each acyl group were 0 and 3, respectively. Two mathematical models of triglyceride assembly are proposed, both of which fit the experimental data. One model assumes that for a certain proportion of the glycerol molecules, the acyl composition of the threesn positions is rigidly controlled independently of the substrate concentration. The other assumes that the various acyl groups are distributed on the threesn positions of glycerol with different affinities.
Different mechanisms of uptake of stearic acid and cholesterol into rabbit jejunal brush border membrane vesicles
Authors: Burdick S. , Keelan M. , Thomson A. B. R. 
Published: November 2006

AbstractThe rate of uptake of stearic acid and cholesterol solubilized in taurocholic acid (TC) was examined in rabbit jejunal brush border membrane vesicles (BBMV). For stearic acid (18∶0) or cholesterol there was an initial rapid rate of uptake, which reached a plateau within approximately 1 min and remained stable thereafter. At low concentrations of 18∶0 and 20 mM, but not 2 mM, TC, there was a curvilinear relationship between the concentration of 18∶0 and uptake, whereas the relationship between cholesterol uptake and concentration was linear over a wide range of values. When the concentration of TC was held constant at increasing concentrations of 18∶0 or cholesterol, there was a linear increase in the rate of uptake. When the concentration of 18∶0 or cholesterol was held constant and the concentration of TC was increased from 2 to 20 mM, the uptake of 18∶0 declined, but the rate of uptake of cholesterol increased. When the concentrations of 18∶0 plus TC, or cholesterol plus TC, were both increased in unison and their ratio was held constant, their rate of uptake increased. Thus, (i) BBMV may be used to assess the rate of uptake of lipids; (ii) the partitioning of cholesterol from bile acid micelles into the BBMV appears to be by way of “collision” of the cholesterol with the membrane. In contrast, the uptake of 18∶0 from the micelle into the membrane vesicles may be by both the collision and the aqueous/dissociation models; and (iii) 18∶0 uptake may be mediated by both a concentration‐dependent and a concentration‐independent component. Thus, stearic acid and cholesterol seem to be taken up from bile acid micelles into rabbit BBMV by different mechanisms.
Effects oftrans fatty acids on lipid accumulation in 3T3‐L1 cells
Authors: Panigrahi Kalpana , Sampugna Joseph 
Published: November 2006

AbstractPrevious work had shown that dietarytrans fatty acids (tFA) resulted in decreased fat deposition in adipose tissue. This study was conducted to see iftFA influence lipid accumulation in Swiss mouse fibroblast 3T3‐L1 cells, which are widely used as an adipocyte model. Cells were cultured in the presence of experimental or control growth media supplemented with fatty acids complexed to bovine serum albumin. Fatty acid compositions of experimental and control growth media were similar except that the octadecenoates in the control growth media werecis fatty acids, whereas those in the experimental media contained bothcis andtrans fatty acids. Cell‐conditioned media and cellular lipids at the preadipocyte and differentiating adipocyte stages were analyzed. At both stages of development, less fat accumulated, in cells cultured in the presence oftFA, due primarily to a decrease in the nonpolar lipid content of cells exposed totFA, and linoleate to arachidonate ratios were higher in cells supplemented withtFA. Calculations comparing sums of saturated and monounsaturated fatty acids in cells at the differentiating adipocyte stage suggested thattFA may have replaced monoun‐saturated fatty acids in the nonpolar lipid fraction and saturated fatty acids in the polar lipid fraction. The results of these studies are in good agreement with thein vivo effects oftFA seen in previous work with mouse adipose tissue. It was concluded that the 3T3‐L1in vitro model is an appropriate system for further studies oftFA and lipid metabolism in adipose tissue.
Depletion of adipose tissue and peripheral nerve α‐tocopherol in adult dogs
Authors: Pillai Shreekumar R. , Traber Maret G. , Steiss Janet E. , Kayden Herbert J. 
Published: November 2006

AbstractTo assess the relationship between tissue α‐tocopherol depletion and histopathologic or functional changes in nervous tissue, a longitudinal study of male 1‐year‐old beagle dogs, two fed a vitamin E‐deficient diet (0.05±0.02 mg α‐tocopherol/kg;—E dogs) and two fed a vitamin E‐supplemented diet (114±14 mg α‐tocopherol/kg; +E dogs), was carried out. Plasma and adipose tissue α‐tocopherol concentrations neurological examinations, and sensory and motor nerve conduction velocities were determined at approximately 8‐wk, intervals over 109 wk. Tibial nerve α‐tocopherol concentrations were measured at 65 and 109 wk; adjacent sections were examined for histologic changes. In the two—E dogs, plasma α‐tocopherols declined linearly on a semilog plot to <0.1 μg/mL by 109 wk. Plasma α‐tocopherol concentrations were depleted to half of the initial concentrations in approximately 87 d. Adipose tissue α‐tocopherol concentrations (based on wet weight, cholesterol or triglyceride) also declined linearly on semilog plots, and were deleted to half of the initial concentrations in approximately 120 d. Tibial nerve α‐tocopherols (ng/μg cholesterol) in—E dogs decreased to 16% of average +E at 65 wk, and to 2% at 109 wk. neurologic examinations, histologies and nerve conduction velocities were normal in all dogs throughout the study. Our results demonstrate in dogs that depletion of plasma, adipose tissue and nerve α‐tocopherol precedes histologic and functional changes in peripheral nerves during vitamin E deficiency.
α‐tocopherol concentrations of the nervous system and selected tissues of adult dogs fed three levels of vitamin E
Authors: Pillai Shreekumar R. , Traber Maret G. , Steiss Janet E. , Kayden Herbert J. , Cox Nancy R. 
Published: November 2006

AbstractThe effects of dietary vitamin E levels on tissue α‐tocopherol (α−T) concentrations in different parts of the nervous system are largely unknown. Therefore, we measured the α−T contents of nervous and other tissues obtained from beagle dogs fed for two years a vitamin E‐deficient diet (−E, 0.05±0.02 mg vitamin E/kg diet, n=2), a vitamin E‐supplemented diet (+E, 114±14 mg/kg, n=2), or a standard chow diet (En, 74±6 mg/kg, n=3). Brain regions and spinal cords of +E dogs contained about double the α−T concentrations of En dogs, and about 10‐fold those of −E dogs. The various brain regions of −E dogs, compared with En dogs, retained 12–18% of the α−T concentrations, with the exception of the caudal colliculus, which retained 48%. Peripheral nerve α−T concentrations in +E dogs (67 ng/mg wet weight) were nearly 5‐fold higher than in En dogs (13.4±5.9 ng/mg) and 80‐fold higher than in −E dogs (0.8 ng/mg). Within each dietary group, the lowest α−T concentrations in the central nervous system (CNS) were in the spinal cord. Peripheral nerves were the most susceptible to vitamin E repletion or depletion: in +E dogs, nerves contained higher concentrations of α−T than most brain regions; in En dogs, they contained similar concentrations; but in −E dogs, they contained less α−T than most brain regions. Muscles and other tissues of −E dogs retained from 1 to 10% of En values. The studies demonstrate that the CNS conserved α−T compared to peripheral nerves and nonnervous tissues in adult dogs, but contained lower absolute concentrations of α−T compare with most other tissues.
γ‐tocotrienol as a hypocholesterolemic and antioxidant agent in rats fed atherogenic diets
Authors: Watkins T. , Lenz P. , Gapor A. , Struck M. , Tomeo A. , Bierenbaum M. 
Published: November 2006

AbstractThis study was designed to determine whether incorporation of γ‐tocotrienol or α‐tocopherol in an atherogenic diet would reduce the concentration of plasma cholesterol, triglycerides and fatty acid peroxides, and attenuate platelet aggregability in rats. For six weeks, male Wistar rats (n=90) were fed AIN76A semisynthetic test diets containing cholesterol (2% by weight), providing fat as partially hydrogenated soybean oil (20% by weight), menhaden oil (20%) or corn oil (2%). Feeding the ration with menhaden oil resulted in the highest concentrations of plasma cholesterol, low and very low density lipoprotein cholesterol, triglycerides, thiobarbituric acid reactive substances and fatty acid hydroperoxides. Consumption of the ration containing γ‐tocotrienol (50 μ/kg) and α‐tocopherol (500 mg/kg) for six weeks led to decreased plasma lipid concentrations. Plasma cholesterol, low and very low density lipoprotein cholesterol, and triglycerides each decreased significantly (P<0.001). Plasma thiobarbituric acid reactive substances decreased significantly (P<0.01), as did the fatty acid hydroperoxides (P<0.05), when the diet contained both chromanols. Supplementation with γ‐tocotrienol resulted in similar, though quantitatively smaller, decrements in these plasma values. Plasma α‐tocopherol concentrations were lowest in rats fed menhaden oil without either chromanol. Though plasma α‐tocopherol did not rise with γ‐tocotrienol supplementation at 50 mg/kg, γ‐tocotrienol at 100 mg/kg of ration spared plasma α‐tocopherol, which rose from 0.60±0.2 to 1.34±0.4 mg/dL (P<0.05). The highest concentration of α‐tocopherol was measured in plasma of animals fed a ration supplemented with α‐tocopherol at 500 mg/kg. In response to added collagen, the partially hydrogenated soybean oil diet without supplementary cholesterol led to reduced platelet aggregation as compared with the cholesterol‐supplemented diet. However, γ‐tocotrienol at a level of 50 mg/kg in the cholesterol‐supplemented diet did not significantly reduce platelet aggregation. Platelets from animals fed the menhaden oil diet released less adenosine triphosphate than the ones from any other diet group. The data suggest that the combination of γ‐tocotrienol and α‐tocopherol, as present in palm oil distillates, deserves further evaluation as a potential hypolipemic agent in hyperlipemic humans at atherogenic risk.
Inhibition by cardiolipins of platelet‐activating factor‐induced rabbit platelet activation
Authors: Tsoukatos Demokritos , Demopoulos Constantinos A. , Tselepis Alexandros D. , Moschidis Michael C. , Donos Andreas , Evangelou Angelos , Benveniste Jaques 
Published: November 2006

AbstractEvidence is presented that cardiolipin, a naturally occurring phospholipid, inhibits the aggregatory effect of platelet‐activating factor (paf) on rabbit plateletsin vitro. Bovine heart cardiolipin was shown to inhibit the aggregation of washed rabbit platelets induced by 1×10−10 M and 2×10−10 M paf with IC50 values (doses for half‐maximal inhibition) of 8.4±0.8×10−7 M and 2.6±0.6×10−6 M, respectively. Phosphonocardiolipin was also able to inhibit platelet aggregation induced by 1× 10−10 M paf with an IC50 value of 3±1×10−7M. Both compounds, in concentrations up to 1×10−5 M, were unable to aggregate washed rabbit platelets and failed to inhibit the aggregation induced by 0.9 and 1.8 μM adenosine diphosphate or 0.2–1.0 μM arrchidonic acid. By contrast, the acetylated derivative of cardiolipin exerted an aggregatory effect on aspirin‐treated rabbit platelets in the presence of creatine phosphate/creatine phosphokinase. This aggregation was inhibited by the specific paf antagonists BN 52021 and WEB 2086. Also, platelets treated with acetyl‐cardiolipin were insensitive to the aggregatory effect of paf. Phosphatidic acid, phosphatidylglycerol,bis(dipalmitoylglycero)phosphate and their phosphono analogues were totally inactive. Similar data were obtained when platelet‐rich plasma was used instead of washed rabbit platelets. Our results support the hypothesis that the effect of cardiolipin is mediated through specific paf receptors that act on the rabbit platelet membrane.