bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dietary docosahexaenoic acid affects stearic acid desaturation in spontaneously hypertensive rats
Authors: Engler Marguerite M. , Bellenger‐Germain Sandrine H. , Engler Mary B. , Narce Michel M. , Poisson Jean‐Pierre G. 
Published: November 2006

AbstractDocosahexaenoic acid (DHA, 22∶6n−3) is an n−3 polyunsaturated fatty acid which attenuates the development of hypertension in spontaneously hypertensive rats (SHR). The effects of DHA on delta‐9‐desaturase activity in hepatic microsomes and fatty acid composition were examined in young SHR. Two groups of SHR were fed either a DHA‐enriched diet or a control diet for 6 wk. Desaturase activity and fatty acid composition were determined in hepatic microsomes following the dietary treatments. Delta‐9‐desaturase activity was decreased by 53% in DHA‐fed SHR and was accompanied by an increase in 16∶0 and a reduction in 16∶1n−7 content in hepatic microsomes. The DHA diet also increased the levels of eicosapentaenoic acid (20∶5n−3) and DHA. The n−6 fatty acid content was also affected in DHA‐fed SHR as reflected by a decrease in gamma‐linolenic acid (18∶3n−6), arachidonic acid (20∶5n−6), adrenic acid (22∶4n−6), and docosapentaenoic acid (22∶5n−6). A higher proportion of dihomo‐gamma‐linolenic acid (20∶3n−6) and a lower proportion of 20∶4n−6 is indicative of impaired delta‐5‐desaturase activity. The alterations in fatty acid composition and metabolism may contribute to the antihypertensive effect of DHA previously reported.
Deuterium uptake and plasma cholesterol precursor levels correspond as methods for measurement of endogenous cholesterol synthesis in hypercholesterolemic women
Authors: Matthan Nirupa R. , Raeini‐Sarjaz Mahmoud , Lichtenstein Alice H. , Ausman Lynne M. , Jones Peter J. H. 
Published: November 2006

AbstractTo assess the validity of two techniques used to measure human cholesterol synthesis, the rate of uptake of deuterium (D) into plasma free cholesterol (FC), and plasma cholesterol precursor (squalene, lanosterol, desmosterol and lathosterol) levels were compared in 14 women [65–71 yr with low density lipoprotein‐cholesterol (LDL‐C)≥3.36 mmol·l−1]. Subjects consumed each of six diets for 5‐wk periods according to a randomized crossover design. The experimental diets included a baseline diet (39% energy as fat, 164 mg chol·4.2 MJ−1) and five reduced‐fat diets (30% of energy as fat), where two‐thirds of the fat was either soybean oil; squeeze, tub or stick margarines; or butter. Fractional and absolute synthesis rates (FSR and ASR) of FC were determined using the deuterium incorporation (DI) method, while cholesterol precursor levels were measured using gas‐liquid chromatography. Data were pooled across diets for each variable and correlation coefficients were calculated to determine if associations were present. There was good agreement among levels of the various cholesterol precursors. In addition, FSR in pools/d (p·d−1) and ASR in grams/d (g·d−1) were strongly associated with lathosterol (r=0.72 and 0.71,P=0.0001), desmosterol (r=0.75 and 0.75,P=0.0001), lanosterol (r=0.67 and 0.67), and squalene (r=0.69 and 0.68) when levels of the precursors were expressed as μmol·mmol−1C. Significant but lower correlations were observed between the D uptake and plasma cholesterol precursor levels when the latter were expressed in absolute amounts (μmol·L−1). The wide range of fatty acid profiles of the experimental diets did not influence the degree of association between methods. In conclusion, the DI method and levels of some cholesterol precursors correspond as methods for shortterm measurement of cholesterol synthesis.
Production of eicosapentaenoic acid by a recombinant marine cyanobacterium, Synechococcus sp.
Authors: Yu Reiko , Yamada Akiko , Watanabe Kazuo , Yazawa Kazunaga , Takeyama Haruko , Matsunaga Tadashi , Kurane Ryuichiro 
Published: November 2006

AbstractThe eicosapentaenoic acid (EPA) synthesis gene cluster from an EPA‐producing bacterium, Shewanella sp. SCRC‐2738, was cloned into a broad‐host range vector, pJRD215, and then introduced into a marine cyanobacterium, Synechococcus sp. NKBG15041c, by conjugation. The transconjugant cyanobacteria produced 3.7±0.2% (2.24±0.13 mg/L) EPA (n‐3) and 2.5 ±0.2% (1.49±0.06 mg/L) eicosatetraenoic acid (n‐3) of the total fatty acids when the cells were cultured at 23°C at a light intensity of 1,000–1,500 Lux. The EPA and eico‐satetraenoic acid contents of the cells were increased to 4.6±0.6% (3.86±1.11 mg/L) and 4.7±0.3% (3.86±0.82 mg/L), and 7.5±0.3% (1.76±0.10 mg/L) and 5.1±0.2% (1.19±0.06 mg/L) when they were cultured at low temperature (18°C) and at lower light intensity (40 Lux), respectively.
Absorption by rats of tocopherols present in edible vegetable oils
Authors: Porsgaard Trine , Høy Carl‐Erik 
Published: November 2006

AbstractThe absorption of tocopherols (α, γ, and σ) and fatty acids from rapeseed (RO), soybean (SOO), and sunflower (SUO) oil, both from the natural oils and from the oils following moderate heating (180°C for 15 min), was measured in lymphcannulated rats. Oils were administered as emulsions through a gastrostomy tube, and lymph samples were collected for 24 h. The composition of tocopherols in oils and lymph fractions was measured by high‐performance liquid chromatography, and fatty acids were measured by gas‐liquid chromatography. The highest accumulated transport of α‐tocopherol was observed after SUO administration, the lowest after SOO, with RO in between, corresponding to their relative contents (41.6±8.8, 32.7±5.0, and 24.9±4.3 μg at 24 h after administration of SUO, RO, and SOO, respectively). The calculated recoveries (in %) 24 h after oil administration were 21.4±4.5, 45.7±7.0, and 78.8±13.5 for SUO, RO, and SOO, respectively, suggesting that the absorption efficiency decreased when the α‐tocopherol concentration increased. The recovery of α‐tocopherol was higher than the recoveries of γ‐and σ‐tocopherol, indicating that the different tocopherols were not absorbed to the same extent or with similar rates. No differences between unheated and heated oils were observed in the absorption of tocopherols, whereas heating led to lower absorption of fatty acids, thus showing no direct association between absorption of tocopherols and fatty acids.
Escherichia coli sepsis increases hepatic apolipoprotein B secretion by inhibiting degradation
Authors: Phetteplace Hope W. , Sedkova Natalia , Hirano Ken‐Ichi , Davidson Nicholas O. , Lanza‐Jacoby Susan P. 
Published: November 2006

AbstractSepsis leads to hypertriglyceridemia in both humans and animals. Previously, we reported that plasma very low density lipoprotein apolipoprotein (apo) B and hepatic production of apoB increased during Escherichia coli sepsis. The present experiments were undertaken to determine whether the altered hepatic secretion of apoB was associated with an increase in synthesis or a decrease in degradation rate. Sepsis was induced in male, Lewis rats (225–275 g) by intravenous injection of 3.8×108 live E. coli colonies/100 g body. Twenty‐four hours later rats were sacrificed, and primary hepatocytes were prepared and incubated overnight with 35S‐methionine. Hepatocytes from E. coli‐treated rats secreted twice as much apoB‐48 and total apoB than the hepatocytes from control rats. Escherichia coli sepsis increased celular triglyceride mass by 86%, which was due to a stimulation in triglyceride synthesis from newly synthesized fatty acids, measured by 3H2O incorporation into triglycerides. The apoB synthesis rate, apoB mRNA levels, and apoB mRNA editing were not altered during E. coli sepsis. The pulse‐chase experiments showed that the rate of apoB degradation decreased in E. coli‐treated rats. These findings demonstrate that the secretion of apoB is regulated posttranslationally during E. coli sepsis by decreasing the degradation of newly synthesized apoB, which contributes to the development of hypertriglyceridemia.
Adaptation of composition and biophysical properties of phospholipids to temperature by the crustacean, Gammarus spp.
Authors: Lahdes Eila , Balogh Gabor , Fodor Elfrieda , Farkas Tibor 
Published: November 2006

AbstractThe compositions of lipid classes as well as the molecular species composition of subclasses (diacyl, alkylacyl, and alkenylacyl forms) of choline and ethanolamine phosphoglycerides in marine amphipod crustaceans, Gammarus spp., collected in the Baltic Sea at 8 and 15°C, were studied in relation to environmental temperature. The structural order of phospholipid multibilayers was also determined. Environmental temperature had little effect on fatty acid composition. The level of some polyunsaturated fatty acids, such as 20:4, even increased in choline and ethanolamine phosphoglycerides at 15°C. Ethanolamine phosphoglycerides were rich in alkenylacyl forms, especially in crustaceans collected at 15°C. The accumulation of sn‐1 monoenic, sn‐2 polyenic diacyl, alkyl, and alkenylacyl phosphatidylethanolamines and diacyl phosphatidylcholines was observed at 8°C. The phospholipid vesicles of crustaceans collected at 8°C were more disordered than expected compared to those obtained from animals collected at 15°C. It was concluded that, in addition to variations in the levels of sn‐1 monoenic and sn‐2 polyenic phospholipid molecular species with temperature, ethanolamine plasmalogens may play a role in controlling membrane biophysical properties in marine amphipod crustaceans.
Cold acclimation or grapeseed oil feeding affects phospholipid composition and mitochondrial function in duckling skeletal muscle
Authors: Chaînier François , Roussel Damien , Georges Bruno , Meister Roger , Rouanet Jean‐Louis , Duchamp Claude , Barre Hervé 
Published: November 2006

AbstractThe phospholipid fatty acid (FA) composition and functional properties of skeletal muscle and liver mitochondria were examined in cold‐acclimated (CA, 4°C) ducklings. Phospholipid FA of isolated muscle mitochondria from CA birds were longer and more unsaturated than those from thermoneutral (TN, 25°C) reared ducklings. The rise in long‐chain and polyunsaturated FA (PUFA, mainly 20∶4n‐6) was associated with a higher State 4 respiration rate and a lower respiratory control ratio (RCR). Hepatic mitochondria, by contrast, were much less affected by cold acclimation. The cold‐induced changes in phospholipid FA profile and functional properties of muscle mitochondria were reproduced by giving TN ducklings a diet enriched in grapeseed oil (GO, rich in n‐6 FA), suggesting a causal relationship between the membrane structure and mitochondrial functional parameters. However, hepatic mitochondria from ducklings fed the GO diet also showed an enrichment in long‐chain PUFA but opposite changes in their biochemical characteristics (lower State 4, higher RCR). It is suggested that the differential modulation of mitochondrial functional properties by membrane lipid composition between skeletal muscle and liver may depend on muscle‐specific factors possibly interacting with long‐chain PUFA and affecting the proton leakiness of mitochondrial membranes.
Effect of n−3 fatty acid deficiency on fatty acid composition and metabolism of aminophospholipids in rat brain synaptosomes
Authors: Ikemoto Atsushi , Ohishi Masayo , Hata Noriaki , Misawa Yoshihisa , Fujii Yoichi , Okuyama Harumi 
Published: November 2006

AbstractDocosahexaenoic acid (DHA, 22∶6n−3) is one of the major polyunsaturated fatty acids esterified predominantly in aminophospholipids such as ethanolamine glycerophospholipid (EtnGpl) and serine glycerophospholipid (SerGpl) in the brain. Synaptosomes prepared from rats fed an n−3 fatty acid‐deficient safflower oil (Saf) diet had significantly decreased 22∶6n−3 content with a compensatory increased 22∶5n−6 content when compared with rats fed an n−3 fatty acid‐sufficient perilla oil (Per) diet. When the Saf group was shifted to a diet supplemented with safflower oil plus 22∶6n−3 (Saf+DHA) after weaning, 22∶6n−3 content was found to be restored to the level of the Per group. The uptake of [3H]ethanolamine and its conversion to [3H]EtnGpl did not differ significantly among the three dietary groups, whereas the formation of [3H]lysoEtnGpl from [3H]ethanolamine was significantly lower in the Saf group than in the other groups. The uptake of [3H]serine, its incorporation into [3H]SerGpl, and the conversion into [3H]EtnGpl by decarboxylation of [3H]SerGpl did not differ among the three dietary groups. The observed decrease in lysoEtnGpl formation associated with a reduction of 22∶6n−3 content in rat brain synaptosomes by n−3 fatty acid deprivation may provide a clue to reveal biochemical bases for the dietary fatty acids‐behavior link.
Identification of the pathway of α‐oxidation of cerebronic acid in peroxisomes
Authors: Sandhir Rajat , Khan Mushfiquddin , Singh Inderjit 
Published: November 2006

AbstractCerebronic acid (2‐hydroxytetracosanoic acid), an α‐hydroxy very long‐chain fatty acid (VLCFA) and a component of cerebrosides and sulfatides, is unique to nervous tissues. Studies were carried out to identify the pathway and the subcellular site involved in the oxidation of cerebronic acid. The results from these studies revealed that cerebronic acid was catabolized by α‐oxidation to CO2 and tricosanoic acid (23:0). Studies with subcellular fractions indicated that cerebronic acid was α‐oxidized in fractions having particulate bound catalase and enzyme systems for the β‐oxidation of VLCFA (e.g., lignoceric acid), suggesting peroxisomes as the subcellular organelle responsible for α‐oxidation of cerebronic acid. Etomoxir, an inhibitor of mitochondrial fatty acid oxidation, had no effect on cerebronic acid α‐oxidation. Further, cerebronic acid oxidation was found to be dependent on the presence of NAD+ but not FAD, NADPH, ATP, Mg2+, or CoASH. Intraorganellar localization studies indicated that the enzyme system for the α‐oxidation of cerebronic acid was associated with the peroxisomal limiting membranes. Studies on cultured fibroblasts from normal subjects and patients with peroxisomal disorders indicated an impairment of α‐oxidation of cerebronic acid in cell lines that lack peroxisomes [e.g., Zellweger syndrome (ZS)]. On the other hand, α‐oxidation of cerebronic acid was found to be normal in cell lines from X‐linked adrenoleukodystrophy, adult Refsum disease, and rhizomelic chondrodysplasia punctata. Our results clearly demonstrate that α‐oxidation of α‐hydroxy VLCFA (cerebronic acid) is a peroxisomal function and that this oxidation is impaired in ZS. Furthermore, this α‐oxidation enzyme system is distinct from the one for the α‐oxidation of β‐carbon branched‐chain fatty acids (e.g., phytanic acid).
Novel lipidic enaminones from a C18 keto‐allenic ester
Authors: Lie Ken Jie Marcel S. F. , Lau Maureen M. L. 
Published: November 2006

AbstractPrimary amines (ammonia, methyl, propyl, octyl, octadecyl, phenyl, benzyl, phenethyl) including methyl esters of amino acids (glycine, dl‐alanine, l‐valine, l‐leucine, L‐tyrosine, and l‐methionine), and secondary amines (dimethyl, diethyl, dipropyl, diisopropyl, dioctyl, and diphenyl) attack regiospecifically the central carbon atom of the allene system of methyl 12‐keto‐9,10‐octadecadienoate (1) to give the corresponding lipidic enaminone derivatives (2–21) with an average yield of 77%. The E‐ and Z‐configuration of the enaminone system of these novel lipid derivatives was confirmed by infrared and nuclear magnetic resonance spectroscopic techniques. Primary amines furnished Z‐enaminones, while secondary amines gave E‐enaminones.
Comparison of silver‐ion high‐performance liquid chromatographic quantification of free and methylated conjugated linoleic acids
Authors: Ostrowska Ewa , Dunshea Frank R. , Muralitharan Morley , Cross Reginald F. 
Published: November 2006

AbstractSilver‐ion high‐performance liquid chromatography was used to fractionate a mixture of conjugated linoleic acid (CLA) isomers (as the free fatty acids, CLAFFA) in commercial CLA mixtures and biological samples. Due to the unchanged retention mechanism, it was assumed that the elution order of the isomers remained the same as that of methyl esters separated on the same column. The most abundant isomers,cis/trans10,12‐18:2 andcis/trans9,11‐18:2, were separated better as free acids on a single column than in the methyl ester form. Quantification of the CLA standard was used as the reference profile to evaluate different methylation methods commonly used to prepare CLA methyl esters for quantitation. Acid‐ and vuigi base‐catalyzed derivatization methods resulted in CLA intraisomerization and losses in total conjugated dienes content. Acid (HCl and BF3) methylations significantly elevated the level oftrans,transisomers and significantly reduced thecis/transisomers. Base methylation, tetramethylguanidine/methanol, resulted in loss oftrans,transisomers, and a substantial loss of total underivatized conjugated dienes. Other catalysts such as the trimethylsilyldiazomethane produced additional peaks of unidentified artifacts. The analysis of CLAFFA appears to provide more accurate quantification of CLA isomers in commercial and biological samples.
Characterization of caldarchaetidylglycerol analogs, dialkyl‐type and trialkyl‐type, from Thermoplasma acidophilum
Authors: Uda Ikuko , Sugai Akihiko , Itoh Yuko H. , Itoh Toshihiro 
Published: November 2006

AbstractThe structures of three kinds of phospholipids (PL‐X, PL‐Y, and PL‐T) isolated from Thermoplasma acid‐ophilum have been characterized. The core lipid of PL‐Y was caldarchaeol, and that of PL‐X was archaeol. The composition of the hydrocarbon chains of the PL‐T core lipid was C20 phytane and C40 isoprenoid in a molar ratio of 2 to 1. The major molecular species of the C40 isoprenoid was acyclic without the cyclopentane ring. These three kinds of intact phospholipids commonly had glycerophosphate residues as polar head groups. The structure of PL‐T was characterized as trialkyl‐type caldarchaetidylglycerol, PL‐Y as caldarchaetidylglycerol, and PL‐X as archaetidylglycerol.
Development in lipid analysis: Some new extraction techniques and in situ transesterification
Authors: Carrapiso Ana I. , García Carmen 
Published: November 2006

AbstractThe development of methods for analyzing fatty acids that provide rapid and reliable results is currently in great demand. Recently, different lipid extraction procedures such as microwave or supercritical fluid extraction have been researched. Both procedures avoid the use of large volumes of solvents and provide rapid lipid isolations. Only a few papers have reported work on microwave extraction, but many studies about supercritical fluid extraction have been carried out and have been gaining acceptance within the scientific community. Avoiding the lipid isolation step, by synthesizing fatty acid esters by simultaneous lipid extraction and derivatization through in situ reactions, has also been proposed. The saving of time and reagents is significant. Owing to the differences among the procedures, some knowledge of their characteristics is essential in order to improve methods and achieve reliable and accurate results. Clearly, results depend on factors such as the type of catalysis selected, the use of nonpolar solvents, heating applied during the synthesis, and the degree of suitability of the procedure chosen for the particular features of each sample.
Polyunsaturated fatty acids in plasma lipids of obese children with and without metabolic cardiovascular syndrome
Authors: Decsi Tamás , Csabi Györgyi , Török Katalin , Erhardt Éva , Minda Hajnalka , Burus István , Molnár Szilárd , Molnár Dénes 
Published: November 2006

AbstractPreviously we reported significantly higher values of γ‐linolenic acid (GLA, 18∶3n−6), dihomo‐γ‐linolenic acid (DHGLA, 20∶3n−6), and arachidonic acid (20∶4n−6) in plasma lipid classes in obese children than in nonobese controls. In the present study, fatty acid composition of plasma phospholipids (PL) and sterol esters (STE) was determined by high‐resolution capillary gas‐liquid chromatography in obese children with an without metabolic cardiovascular syndrome [MCS: defined as simultaneous presence of (i) dyslipidemia, (ii) hyperinsulinemia, (iii) hypertension, and (iv) impaired glucose tolerance] and in nonobese controls. Fatty acid composition of PL and STE lipids did not differ between obese children without MCS and controls. Obese children with MCS exhibited significantly lower linoleic acid (LA, 18∶2n−6) values in PL (17.43 [2.36], %wt/wt, median [range from the first to the third quartile]) than obese children without MCS (19.14 [3.49]) and controls (20.28 [3.80]). In contrast, PL GLA values were significantly higher in obese children with (0.13 [0.08]) than in those without MCS (0.08 [0.04]), whereas STE GLA values were higher in obese children with MCS (1.04 [0.72]) than in controls (0.62 [0.48]). DHGLA values in PL were significantly higher in obese children with MCS (4.06 [0.74]) than in controls (2.69 [1.60]). The GLA/LA ratio was significantly higher, whereas the AA/DHGLA ratio was significantly lower in obese children with MCS than in obese children without MCS and in controls. In this study, LA metabolism was affected only in obese children with but not in those without MCS. In obese children with MCS, δ6‐desaturase activity appeared to be stimulated, whereas δ5‐desaturase activity appeared to be inhibited. Disturbances in LA metabolism may represent an additional health hazard within the multifaceted clinical picture of MCS.
Fatty acid chain length and degree of unsaturation are inversely associated with serum triglycerides
Authors: Grimsgaard Sameline , Bønaa Kaare H. , Bjerve Kristian S. 
Published: November 2006

AbstractLittle is known about the association between dietary fatty acids and serum triglyceride concentrations. Plasma fatty acids may reflect dietary intake and can be used to study the relationship between concentrations of individual fatty acids and serum lipids. We examined the cross‐sectional relationship of plasma fatty acids with serum nonfasting triglyceride and total cholesterol concentrations. Relative concentrations of individual plasma phospholipid fatty acids were determined by gas‐liquid chromatography among 4,158 men aged 40–42 yr, who participated in a population study. The pattern of associations between individual fatty acids and cholesterol was different from that between individual fatty acids and triglyceride concentrations. All fatty acids displayed positive associations with total cholesterol concentration except linoleic acid, which was inversely related to cholesterol. In contrast, associations between individual fatty acids and triglyceride concentrations differed in strength and direction depending on both carbon chain length and the degree of unsaturation. Concentrations of very long chain (20 carbon atoms or more) saturated, monounsaturated, and n‐3 polyunsaturated fatty acids showed significant inverse associations with triglycerides, whereas shorter fatty acids within these classes were positively associated with triglyceride concentrations. The present data suggest that the associations between concentrations of serum triglycerides and plasma phospholipid fatty acids depend on both fatty acid chain length and the degree of unsaturation.