bluuebunny/crossref_metadata_2025 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

Docosahexaenoic 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

To 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

The 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

The 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

Sepsis 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

The 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

The 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

Docosahexaenoic 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

Cerebronic 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

Primary 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

Silver‐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

The 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

The 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

Previously 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

Little 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.
Effects of α‐tocopherol and ascorbyl palmitate on the isomerization and decomposition of methyl linoleate hydroperoxides
Authors: Mäkinen E. Marjukka , Hopia Anu I.
Published: November 2006

In order to study antioxidant action on lipid hydroperoxide decomposition, the effects of α‐tocopherol (TOH) and ascorbyl palmitate on the decomposition rate and reaction sequences of 9‐ and 13‐cis,trans methyl linoleate hydroperoxide (cis,trans ML‐OOH) decomposition in hexadecane were studied at 40°C. Decomposition of cis,trans ML‐OOH as well as the formation and isomeric configuration of methyl linoleate hydroxy and ketodiene compounds were followed by high‐performance liquid chromatographic analysis. TOH effectively inhibited the decomposition of ML‐OOH. The decomposition rate was two times slower at 0.2 mM and more than 10 times slower at 2 and 20 mM of TOH. Ascorbyl palmitale (0.2, 2, and 20 mM) slightly accelerated the decomposition of ML‐OOH. Both compounds had an effect on the reaction sequences of ML‐OOH decomposition. At high levels TOH inhibited the isomerization of cis,trans ML‐OOH to trans,trans ML‐OOH through peroxyl radicals and increased the formation of hydroxy compounds. Further, the majority of the hydroxy and ketodiene compounds formed had a cis,trans configuration, indicating that cis,trans ML‐OOH decomposed through alkoxyl radicals without isomerization. These results suggest that when inhibiting the decomposition of hydroperoxides, TOH can act as a hydrogen atom donor to both peroxyl and alkoxyl radicals. In the presence of ascorbyl palmitate, cis,trans ML‐OOH decomposed rapidly but without isomerization. In contrast to TOH, the majority of hydroxy compounds were cis,trans, but the ketodiene compounds were trans,trans isomers. This indicates that ascorbyl palmitate reduced cis,trans ML‐OOH to the corresponding hydroxy compounds. However, the simultaneous formation of trans,trans ketodiene compounds suggests that ML‐OOH decomposition, similar to the control sample, also occurred in these samples. Thus, under these experimental conditions, the reduction of ML‐OOH to more stable hydroxy compounds did not occur to an extent significant enough to inhibit the radical chain reactions of ML‐OOH decomposition.
Vitamin E and probucol reduce urinary lipophilic aldehydes and renal enlargement in streptozotocin‐induced diabetic rats
Authors: Kim Song‐Suk , Gallaher D. D. , Csallany A. Saari
Published: November 2006

Diabetes mellitus is characterized by complications affecting several organs, including the kidney. Lipid peroxidation increases in diabetes and has been implicated in the pathogenesis of diabetic complications. In this study, we examined the ability of two antioxidants, vitamin E and probucol, to reduce lipid peroxidation in vivo and renal hypertrophy, an early stage of diabetic nephropathy, in rats. Animals were divided into four groups: non‐diabetic, diabetic, diabetic treated with vitamin E, and diabetic treated with probucol. Animals were given antioxidants by intraperitoneal injection after induction of diabetes by streptozotocin injection. After 7 wk, lipid peroxidation in vivo was measured by analyzing urinary excretion of lipophilic aldehydes and related carbonyl compounds (LACC) as 2,4‐dinitrophenylhydrazones by high‐performance liquid chromatography. A number of urinary lipophilic nonpolar and polar aldehydes and related carbonyl compounds were identified, almost all of which increased in diabetes. Antioxidant treatment resulted in significantly decreased excretion of urinary LACC excretion. Antioxidant treatment of diabetic rats reduced renal hypertrophy. There was a high correlation between kidney weight and urinary LACC. Since LACC are accepted markers of lipid peroxidation, these results indicate that antioxidants can reduce the elevated lipid peroxidation of diabetes and may slow the onset of diabetic nephropathy.
The effect of γ‐interferon to inhibit macrophage‐high density lipoprotein interactions is reversed by Δ12,14‐prostaglandin J2J2
Authors: Zuckerman Steven H. , Panousis Constantinos , Mizrahi Jacques , Evans Glenn
Published: November 2006

Macrophage activation has been recognized as playing a central role in chronic inflammatory diseases in general and more specifically, in the vascular wall during the progression of atherosclerotic lesions. Macrophage‐activating factors present within the atherosclerotic lesion include the colony‐stimulating factors and gamma interferon (IFNγ). In the present study, the effects of IFNγ on macrophage binding and uptake of fluorochrome‐labeled high density lipoprotein (HDL) were investigated by flow cytometry and by measuring the amount of the type B scavenger receptors CD36 and scavenger receptor type B (SR‐BI) by Northern blot analysis. IFNγ‐, but not granulocyte macrophage colony‐stimulating factor (GM‐CSF)‐treated murine peritoneal macrophages displayed a two‐ to threefold decrease in Dil‐labeled HDI uptake. This effect was observed in the absence of a comparable decrease in SR‐BI meassage and protein or CD36 message. This decrease in both HDL binding and uptake was reversed by the peroxisome proliferator‐activated receptor gamma (PPARγ) agonist, Δ12,14‐prostaglandin J2 (15d‐PGJ2), which also inhibited the IFNγ inductin of the β2 integrin CD1 1a. Furthermore, 15d‐PGJ2 increased the expression of SR‐BI and CD36 message and SR‐BI protein which was reflected in an increase in HDL binding and uptake. These results suggest a role for PPARγ agonists in modulating the IFNγ‐mediated macrophage effector functions relevant to atherosclerotic disease progression.
Fatty acid analysis of blood plasma of patients with alzheimer's disease, other types of dementia, and cognitive impairment
Authors: Conquer Julie A. , Tierney Mary C. , Zecevic Julie , Bettger William J. , Fisher Rory H.
Published: November 2006

Fatty acid differences, including docosahexaenoic acid (DHA; 22:6n‐3) have been shown in the brains of Alzheimer's patients (AD) as compared with normal age‐matched individuals. Furthermore, low serum DHA is a significant risk factor for the development of AD. The relative concentration of DHA and other fatty acids, however, in the plasma of AD patients compared with patients with other kinds of dementias (other dementias; OD), patients who are cognitively impaired but nondemented (CIND), or normal patients is not known. In this study we analyzed the total phospholipid, phosphatidylcholine (PC), phosphatidylethanolamine (PE), and lysophosphatidylcholine (lysoPC) fractions of plasma from patients diagnosed with AD, OD, or CIND and compared them with a group of elderly control subjects with normal cognitive functioning. Plasma phospholipid and PC levels of 20:5n‐3, DHA, total n‐3 fatty acids, and the n‐3/n‐6 ratio were lower in the AD, OD, and CIND groups. Plasma phospholipid 24:0 was lower in the AD, OD, and CIND groups as compared with the group of control patients, and total n‐6 fatty acid levels were higher in the AD and CIND groups only. In the plasma PE fraction, levels of 20:5n‐3, DHA, and the total n‐3 fatty acid levels were significantly lower in the AD, OD, and CIND groups. DHA levels were lower in the lysoPC fraction of CIND individuals only. There were no other differences in the fatty acid compositions of the different phospholipid fractions. Therefore, in AD, OD, and CIND individuals, low levels of n‐3 fatty acids in the plasma may be a risk factor for cognitive impairment and/or dementia. Interestingly, a decreased level of plasma DHA was not limited to the AD patients but appears to be common in cognitive impairment with aging.
In vivo evaluation of the effects of continuous exercise on skeletal muscle triglycerides in trained humans
Authors: Rico‐Sanz Jesus , Moosavi Marjan , Louise Thomas E. , McCarthy John , Coutts Glyn A. , Saeed Nadeem , Bell Jimmy D.
Published: November 2006

Magnetic resonance spectroscopy (1H MRS) and imaging (MRI) were used to investigate the effects of a bout of moderate prolonged exercise on intra (IMCL)‐ and extramyocellular lipid (EMCL) utilization in the soleus, tibialis anterior, and gastrocnemius muscles of five trained human subjects. MRI and 1H MRS measurements were obtained before and after a 90 min run on a calibrated treadmill at a velocity corresponding to 64±1.5% of each subjects' maximal rate of oxygen consumption. There were significant decreases in IMCL following exercise in the tibialis (pre: 22.37±4.33 vs. post: 15.16±3.25 mmol/kg dry wt; P<0.01) and soleus (pre: 36.93±1.45 vs. post: 29.85 ±2.44 mmol/kg dry wt; P<0.01) muscles. There was also a decrease in the gastrocnemius muscle, although this did not reach the level of significance (pre: 33.78±5.35 vs. post: 28.48±5.44 mmol/kg dry weight; P<0.10). No significant changes were observed in EMCL or subcutaneous fat. In conclusion, this study showed that IMCL were significantly utilized in the tibialis and soleus muscles of aerobically endurance‐trained humans. The absence of significant utilization of IMCL in the gastrocnemius may reflect differences in fiber type and/or intensity of contraction for each muscle group.
Hepatic microsomal and peroxisomal docosahexaenoate biosynthesis during piglet development
Authors: Li Zhiying , Kaplan Murray L. , Hachey David L.
Published: November 2006

The roles of peroxisomes and microsomes on the biosynthetic pathway for docosahexaenoic acid (DHA) from α‐linolenic acid (ALA) were investigated. Microsomes and peroxisomes were prepared from livers of fetal and neonatal piglets by a combination of differential and gradient layer centrifugation. Microsomes, peroxisomes, and combined cell fractions were incubated with [13C‐U]18∶3n−3. The [M] and [M+18] isotopomers of the fatty acids in the long‐chain polyunsaturated fatty acid (LCPUFA) n−3 pathway were detected by gas chromatography‐mass spectrometry. The quantity of each fatty acid was determined by gas chromatography, and synthesis of each fatty acid was calculated for a 30‐min period. Synthesis of DHA was not detected in combined fetal liver fractions. The data suggest that DHA in the fetus is probably supplied from maternal sources through the placenta. In either singly incubated microsomal or peroxisomal preparations from neonatal livers, no DHA synthesis was detected. After combination of the microsomal and peroxisomal fractions, DHA synthesis was evident and increased rapidly between birth and 2 wk of age. This is the first demonstration of the entire biosynthetic LCPUFA n−3 pathway in subcellular organelles starting from isotopically labeled ALA to the final product, DHA, with all the intermediates present and isotopically labeled. The primary importance of the data is that it unequivocally demonstrates that peroxisomes are required for biosynthesis of DHA from ALA.
Dietary cholesterol induces changes in molecular species of hepatic microsomal phosphatidylcholine
Authors: Bernasconi Ana M. , Garda Horacio A. , Brenner Rodolfo R.
Published: November 2006

After 21 days on a diet containing 1g% cholesterol and 0.5g% cholic acid, rats had an increased content of cholesterol in liver microsomal lipids. In liver, both cholesterol content and δ9 desaturase activity increased, whereas δ6 and δ5 desaturase activities decreased. These changes correlated with increases in oleic, palmitoleic, and linoleic acids and decreases in arachidonic and docosahexenoic acids in total microsomal lipids. Similar fatty acid changes were found in phosphatidylcholine (PC), the principal lipid of the microsomal membrane. In PC the predominant molecular fatty acid species (67% of the total) in the control rats were 18:0/20:4, 16:0/20:4, and 16:0/18:2; and they mainly determined the contribution of PC to the biophysical and biochemical properties of the phospholipid bilayer. The cholesterol diet decreased specifically the 18:0/20:4 species, and to a lesser extent, 16:0/20:4 and 18:0/22:6. The 18:1‐containing species, especially 18:1/18:2 and less so 16:0/18:1 and 18:1/20:4, were increased. A new 18:1/18:1 species appeared. The independent effects of the presence of cholesterol and change of the fatty acid composition of the phospholipid bilayer of liver microsomes on the packing were studied by fluorescence methods using 6‐lauroyl‐2,4‐dimethylaminonaphthalene, 1,6‐diphenyl‐1,3,5‐hexatriene and 1‐(4‐trimethylammonium phenyl)‐6‐phenyl‐1,3,5‐hexatriene, which test different parameters and depths of the bilayer. Data showed that the increase of cholesterol in the membrane, and not the change of the fatty acid composition of phospholipids, was the main determinant of the increased bulk packing of the bilayer. The increase of fluid oleic‐ and linoleic‐containing species almost compensated for the drop in 20:4‐ and 22:6‐containing molecules. But the most important effect was that the general drop in essential n‐6 and n‐3 polyunsaturated fatty acids meant that this endogenous source for the needs of the animal decreased.
Effect of medium‐chain fatty acid positional distribution in dietary triacylglycerol on lymphatic lipid transport and chylomicron composition in rats
Authors: Carvajal Octavio , Nakayama Masahiro , Kishi Taiji , Sato Masao , Ikeda Ikuo , Sugano Michihiro , Imaizumi Katsumi
Published: November 2006

The present study was carried out to examine if the positional distribution of medium‐chain fatty acid (MCF) in dietary synthetic fat influences lymphatic transport of dietary fat and the chemical composition of chylomicrons in rats with permanent cannulation of thoracic duct. Four types of synthetic triacylglycerol were prepared: (i) sn‐1(3) MCF‐sn 2 linoleic acid, (ii) interesterified sn‐1(3) MCF‐sn 2 linoleic acid, (iii) sn‐2 MCF‐sn‐1(3) linoleic acid, and (iv) interesterified sn‐2 MCF‐sn‐1(3) linoleic acid. A purified diet composed of equal amounts of the synthetic fat and cocoa butter was given to rats with permanent lymph duct cannulation. The positional distribution of MCF in the dietary fat had no significant effect on the lymph flow, triacylglycerol output, phospholipid output, lipid composition of chylomicrons, or the particle size. The positional distribution of MCF in the synthetic triacylglycerol was maintained in the chylomicron triacylglycerol. These results showed that MCF in the dietary triacylglycerol is transported into lymphatics and the positional distribution is well preserved in chylomicron triacylglycerol.
Kinetics of 2‐monoacylglycerol acyl migration in model chylomicra
Authors: Lyubachevskaya Galina , Boyle‐Roden Elizabeth
Published: November 2006

In the metabolism of triacylglycerol (TG)‐rich lipoproteins, 2‐monoacylglycerols (2‐MG) are produced by lipoprotein lipase (LPL) hydrolysis of TG. The metabolic fate of 2‐MG is not known with certainty. 2‐MG that accumulate on the chylomicra surface have been proposed to isomerize spontaneously to 1(3)‐MG, which are then hydrolyzed by LPL to free fatty acids and glycerol. In this study the rate and the effect of acyl chain saturation on the spontaneous acyl migration of 2‐MG in in vitro model chylomicra emulsions were determined. After 1 h of incubation at 37°C, less than 20% of 2‐monoolein (2‐MO) or 2‐monopalmitin (2‐MP) spontaneously isomerized to 1(3)‐MO or 1(3)‐MP, respectively. Accordingly, it was concluded that spontaneous isomerization of 2‐MG is not the major mechanism for 2‐MG metabolism post‐TG hydrolysis in chylomicra. Isomerization rates, expressed as decrease in percentage of 2‐MG remaining per hour, were −5.12 and −5.86 in water, and −0.43 and −0.41 in hexane for 2‐MO and 2‐MP, respectively. There was no significant difference between the isomerization rates of 2‐MO and 2‐MP. Thus, in the present study, saturation of the MG acyl chain did not influence spontaneous acyl migration in either water or hexane, but isomerization of 2‐MG was faster in water than in hexane.
Unusual lipid composition of a Bacillus sp. Isolated from Lake Pomorie in Bulgaria
Authors: Carballeira Nstor M. , Guzmn Aikomari , Nechev Jordan T. , Lahtchev Kantcho , Ivanova Albena , Stefanov Kamen
Published: November 2006

The lipid composition of a Bacillus sp., isolated from Lake Pomorie in Bulgaria, was unusual and consisted of 26 different fatty acids between C12 and C26, with anteiso C15−C17 saturated fatty acids predominating. The furan fatty acid, 10,13‐epoxy‐11‐methyloctadeca‐10,12‐dienoic acid, was also identified, a new finding for this genus. The hydrocarbons consisted of 30 different monounsaturated hydrocarbons, between C25 and C30, with the iso‐iso, iso‐anteiso, anteiso‐anteiso, iso‐normal, and anteiso‐normal methyl branching for odd‐numbered chains, and the iso‐iso, iso‐anteiso, iso‐normal, and anteiso‐normal methyl branching for even‐numbered chains. The double bond positions in these hydrocarbons were determined by dimethyl disulfide derivatization followed by GC‐MS, and the double‐bond cis configuration was confirmed by infrared spectroscopy. Some previously unknown hydrocarbons in bacteria, such as (Z)‐3,21‐dimethyl‐9‐tricosene, (Z)‐3,21‐dimethyl‐10‐tricosene, (Z)‐2,24‐dimethyl‐11‐pentacosene, and (Z)‐2,25‐dimethyl‐13‐hexacosene were identified. Sterols were detected and were based on the sitosterol nucleus.
Lipid class composition of the protozoan Perkinsus marinus, an oyster parasite, and its metabolism of a fluorescent phosphatidylcholine analog
Authors: Soudant P. , Chu F.‐L. E. , Marty Y.
Published: November 2006

Perkinsus marinus is one of two important protozoan parasites of the eastern oyster, Crassostrea virginica. The other is Haplosporidium nelsoni. Lipids extracted from 7‐d‐old in vitro cultured P. marinus meronts, incubated with fluorescent‐labeled phosphatidylcholine (FL PC) and nonincubated P. marinus meronts, were analyzed by a high‐performance liquid chromatography (HPLC) system equipped with a diol phase column, in combination with thin‐layer chromatography coupled with a flameionization detector (TLC/FID), and high‐performance thin‐layer chromatography (HPTLC). Various polar and neutral lipid classes were separated by HPLC using a two‐gradient solvent system. Five polar lipid classes—phosphatidylcholine (PC), phosphatidylethanolamine (PE), cardiolipin (CL), sphingomyelin (SM), and phosphatidylserine (PS)—were identified from P. marinus extracts. Four neutral lipid classes—triacylglycerol (TAG), steryl ester (SE), cholesterol (CHO), and fatty alcohol—were distinguished. TLC/FID analysis of meront lipids showed that the weight percentages of PC, PE, CL, SM, PS/PI, TAG, SE, and CHO were 21, 10.7, 4, 2.3, 4.3, 48.7, 7.8, and 1.2%, respectively. HPLC and HPTLC analyses revealed the presence of two SM and PS isomers in P. marinus extracts. Perkinsus marinus effectively incorporated FL PC acquired from the medium and metabolized it to various components (i.e., free fatty acid, monoacylglycerol, diacylglycerol, TAG, PE, and CL). Uptake and interconversion of FL PC in P. marinus meronts increased with time. After 48 h the total uptake of fluorescence (FL) was 28.9% of the FL PC added to the medium, and 43% of the incorporated FL resided in TAG.
Analysis of the addition products of α‐tocopherol with phosphatidylcholine‐peroxyl radicals by high‐performance liquid chromatography with chemiluminescent detection
Authors: Yamauchi Ryo , Hara Yuji , Murase Hironobu , Kato Koji
Published: November 2006

A chemiluminescence‐based high‐performance liquid chromatographic method was developed for the analysis of the addition products of α‐tocopherol with phosphatidylcholine‐peroxyl radicals (TOO‐PC). The TOO‐PC eluted from a reversed‐phase column was reacted with a chemiluminescent reagent consisting of a Cypridina luciferin analog and a lipid‐soluble iron chelate in acidic methanol at 50°C, and the generated chemiluminescence was monitored. The detection limit for TOO‐PC by this method was about 1 pmol. This method was applied to the detection of TOO‐PC in the peroxidized membranes prepared from rabbit erythrocyte ghosts. When the erythrocyte ghosts were peroxidized by the addition of a water‐soluble free radical initiator, a peak corresponding to TOO‐PC was detected on the chromatogram with chemiluminescent detection. The amount of TOO‐PC in the erythrocyte membranes increased with the depletion of endogenous α‐tocopherol. The results indicate that this method proved useful for the detection of the TOO‐PC formed by the peroxyl‐radical scavenging reactions of α‐tocopherol in biological systems.
Fatty acid‐specific, regiospecific, and stereospecific hydroxylation by cytochrome P450 (CYP152B1) from Sphingomonas paucimobilis: Substrate structure required for α‐hydroxylation
Authors: Matsunaga Isamu , Sumimoto Tatsuo , Ueda Atsuo , Kusunose Emi , Ichihara Kosuke
Published: November 2006

Fatty acid α‐hydroxylase from Sphingomonas paucimobilis is an unusual cytochrome P450 enzyme that hydroxylates the α‐carbon of fatty acids in the presence of H2O2. Herein, we describe our investigation concerning the utilization of various substrates and the optical configuration of the α‐hydroxyl product using a recombinant form of this enzyme. This enzyme can metabolize saturated fatty acids with carbon chain lengths of more than 10. The Km value for pentadecanoic acid (C15) was the smallest among the saturated fatty acids tested (C10–C18) and that for myristic acid (C14) showed similar enzyme kinetics to those seen for C15. As shorter or longer carbon chain lengths were used, Km values increased. The turnover numbers for fatty acids with carbon chain lengths of more than 11 were of the same order of magnitude (103 min−1), but the turnover number for undecanoic acid (C11) was less. Dicarboxylic fatty acids and methyl myristate were not metabolized, but monomethyl hexadecanedioate and ω‐hydroxypalmitic acid were metabolized, though with lower turnover values. Arachidonic acid was a good substrate, comparable to C14 or C15. The metabolite of arachidonic acid was only α‐hydroxyarachidonic acid. Alkanes, fatty alcohols, and fatty aldehydes were not utilized as substrates. Analysis of the optical configurations of the α‐hydroxylated products demonstrated that the products were S‐enantiomers (more than 98% enantiomerically pure). These results suggested that this P450 enzyme is strictly responsible for fatty acids and catalyzes highly stereo‐ and regioselective hydroxylation, where structure of ω‐carbon and carboxyl carbon as well as carbon chain length of fatty acids are important for substrate‐enzyme interaction.
Utilization of docosahexaenoic acid from intravenous egg yolk phospholipid
Authors: Morris Scott , Simmer Karen , Gibson Robert
Published: November 2006

Docosahexaenoic acid (DHA, 22∶6n−3) is provided directly to human premature infants during parenteral nutrition from the egg yolk fraction of an intravenous fat emulsion. This study aimed to determine whether the high egg yolk phospholipid content of Intralipid 10% (IL 10%, Pharmacia, Uppsala, Sweden) relative to the standard emulsion Intralipid 20% (IL 20%, Pharmacia) could be a strategy to increase the delivery of DHA to the developing brain. Male, Large White piglets were randomly selected from sows 3 d after birth. Piglets were assigned to receive a 9‐d continuous intravenous infusion commencing 5 d after birth of either Intralipid (IL) 10%, IL 20%, or Lipofundin S 20% (LFS; B. Braun, Melsungen, Germany). There were four piglets in each treatment group. IL 10% provides twice as much DHA as IL 20%, while LFS provides no DHA. Protein and other nutrients were provided enterally using a low‐fat milk formula. After 9 d, animals were killed, and the fatty acid compositions of blood, liver, and cerebral cortex were analyzed. IL 10% infusion approximately doubled the amount of plasma phospholipid DHA (μg/mL of plasma) in comparison to IL 20%. However, red blood cells, liver, and cerebral cortex phospholipid DHA levels were indistinguishable between these two groups. LFS was associated with reduced levels of DHA in plasma, red blood cell and liver phospholipids in comparison to IL 20%. We conclude that infusion of additional phospholipid is an ineffective strategy for increasing DHA delivery to piglet tissues. This may be due to the formation of inert phospholipid particles in plasma. The data do not support the concept of using IL 10% as a means of providing additional DHA to premature human infants.