bluuebunny/crossref_metadata_2025 huggingface dataset:
Phospholipid molecular species from human placenta lipids
Authors: Bayon Y. , Croset M. , Chirouze V. , Tayot J. L. , Lagarde M.
Published: November 2006

The phospholipid molecular species from a large‐scale preparation of human placenta lipids were analyzed. The major placental phospholipids were choline glycerophospholipids (CPL) (53.2 wt%), sphingomyelin (21.7 wt%) and ethanolamine glycerophospholipids (EPL) (14.6 wt%). 1,2‐Diacyl‐glycerophosphocholine was the most abundant subclass of CPL (91.7 mol%), while EPL contained 1,2‐diacyl (54.6 mol%) and 1‐alk‐1′‐enyl‐2‐acyl (43.8 mol%) subclasses. The level of polyunsaturated fatty acids (PUFA) in total phospholipids was remarkably constant (38.4–39.9 mol%) within all placental batches tested. The long‐chain PUFA, mainly 20∶4n−6 and 22∶6n−3 of the n−6 and n−3 series, respectively, were found in high proportion in all phospholipid classes, especially in EPL (46.7 mol%) and in inositol glycerophospholipids (IPL) (39.9 mol%). CPL and serine glycerophospholipids were much richer in 18∶1n−9 and 18∶2n−6. High levels of molecular species with arachidonic acid in thesn‐2 position were found particularly in 1‐alk‐1′‐enyl‐2‐acyl‐glycerophospho‐ethanolamine (with 24.0 mol% 16∶0 and 22.0 mol% 18∶0 insn‐1 position) and in 1,2‐diacyl glycerophosphoinositol with 42.6 mol% 18∶0 insn‐1 position. EPL subclasses were rich in 22∶6n−3, which occurs mainly as 16∶0/22∶6n−3 (11.7 mol%) in the polasmalogen form and as 18∶0/22∶6n−3, 16∶0/22∶6n−3 and 18∶1/22∶6n−3 in the diacyl forms. Based on their availability and composition, placental phospholipids could be of interest, for example, for supplementing artificial milk preparations with n−3 and n−6 long‐chain PUFA for newborn infants with insufficiently developed 18∶2n−6 and 18∶3n−3 desaturation/elongation.
Dietary fat effects on hepatic lipid peroxidation and enzymes of H2O2 metabolism and NADPH Generation
Authors: Chen Li‐Chuan , Boissonneault Gilbert , Hayek Michael G. , Chow Ching K.
Published: November 2006

The purpose of this study was to determine the effects of dietary fat quantity and fatty acid composition on hepatic H2O2‐metabolizing systems, activities of NADPH‐generating enzymes and lipid peroxidation. Onemonth‐old male C57BL/6J mice were fed one of six diets: (i) 5% fat, rich in 18∶2n−6 fatty acid (5% N−6); (ii) 20% fat, rich in 18∶3n−3 (N−3); (iii) 20% fat, rich in 18∶2n−6 (N−6); (iv) 20% fat, rich in 18∶1n−9 (N−9); (v) 20% fat, rich in saturated fatty acids (SAT); and (vi) 20% fat, deficient in essential fatty acids (EFAD); for 11 wk. Comparisons between animal groups receiving different fat quantities showed that activities of glucose‐6‐phosphate dehydrogenase (G6PDH, EC 1.1.1.49) and malic enzyme (ME, EC 1.1.1.40) and the levels of conjugated dienes were significantly lower in the N−6 than in 5% N−6 group. Conversely, activities of catalase (CAT, EC 1.11.1.6) and seleniumglutathione peroxidase (SeGSHPx, EC 1.11.1.9) were higher in the N−6 than in 5% N−6 group. Among the five dietary groups receiving 20% fat but differing in fatty acid composition, CAT activity was lower in the N−9 group, SeGSHPx activity was lower in the EFAD group, and glutathione reductase (GSSGR, EC 1.6.4.2) activity was higher in the N−6 than in the N−3, N−9, SAT and EFAD groups. The EFAD group had much higher levels of total lipids and conjugated dienes, as well as activities of NADPH‐generating enzymes, including G6PDH, ME and isocitrate dehydrogenase (EC 1.1.1.42), than the other four high‐fat groups. The hepatic levels of malondialdehyde were not different among the five groups fed 20% fat. In the EFAD group, higher hepatic lipid content can be attributed to higher activities of NADPH‐generating enzymes, and the elevation of conjugated diene levels may be related to increased oxygenation of 20∶−6 (Mead acid)via the lipoxygenase/cyclooxygenase pathway. In short, both dietary fat quantity and fatty acid composition selectively affected hepatic H2O2‐metabolizing systems, activities of NADPH‐generating enzymes and lipid peroxidation status.
Diabetes increases excretion of urinary malonaldehyde conjugates in rats
Authors: Gallaher Daniel D. , Csallany A. Saari , Shoeman Don W. , Olson Judith M.
Published: November 2006

The effect of streptozotocin‐induced diabetes on the urinary excretion of thiobarbituric acid test‐positive materials was examined. In diabetic rats, urinary excretion of thiobarbituric acid reactive substances was increased 5‐fold over that in nondiabetic animals. High‐performance liquid chromatography of urine samples revealed that five of the six fractions previously found to be increased in vitamin E deficiency [Lee, H.‐S., Shoeman, D.W., and Csallany, A.S. (1992)Lipids 27, 124–128] were also significantly increased in streptozotocin‐induced diabetes. The data suggest that a high level of oxidative stress is induced by uncontrolled diabetes in rats.
Fatty acid composition of brain phospholipids in aging and in Alzheimer’s disease
Authors: Söderberg M. , Edlund C. , Kristensson K. , Dallner G.
Published: November 2006

The two major phospholipid classes, namely, phosphatidylethanolamines (PE) and phosphatidylcholines (PC), were studied in four different regions of human brain,i.e., in frontal gray matter, frontal white matter, hippocampus and in pons. The fatty acid (FA) compositions of these phospholipids were found to be specific for the different regions. PC contains mostly saturated and 18∶1 FA, while PE is rich in polyunsaturated FA. Aging has no influence on the FA compositions, while in Alzheimer’s disease (AD) PE is modified in all four regions, particularly in frontal gray matter and in hippocampus. The abundance of the major monounsaturated FA of PE, 18∶1, is not significantly altered in Alzheimer’s disease, but there is a substantial increase in the relative amounts of the saturated components 14∶0, 16∶0 and 18∶0. This is paralleled by a decrease in the polyunsaturated FA 20∶4, 22∶4 and 22∶6. It is not clear whether the changes observed are specific for AD. Changes in saturated/polyunsaturated FA ratio are likely to influence cellular function, which in turn may cause certain neural deficiencies. The findings do not support the hypothesis that AD reflects an accelerated aging process.
Study on the lipid composition of aging fischer‐344 rat lymphoid cells: Effect of long‐term calorie restriction
Authors: Laganiere Serge , Fernandes Gabriel
Published: November 2006

Long‐term calorie restriction (LCR) is widely known to increase the survival rate of laboratory rodents and appears to retard the aging and senescence process. The present study was undertaken in Fischer‐344 male rats maintained onad libitum (AL) or LCR (40% less food intake than AL starting at 6 weeks of age). Age‐associated changes in the proliferative response of lymphoid cells to mitogenic stimuli were studied in relation to alterations in the fatty acid composition of adherent and nonadherent‐enriched subpopulations of spleen cells. Increases in spleen cell long‐chain highly unsaturated fatty acids (20∶4, 22∶4 and 22∶5) were accompanied by decreases in linoleic acid (18∶2) in aging AL‐fed rats. However, LCR stabilized levels of 18∶2 and prevented the rise in highly unsaturated fatty acids. In addition, LCR markedly modulated the fatty acid profiles of thymocytes and bone marrow cells. A 70% decline in concanavalin A (Con A) stimulated [3H]thymidine uptake of spleen cells from AL animals was normalized by LCR. Splenic reduced glutathione (GSH), a potential modulator of the mitogenic response, was unaffected by age and nutritional regimen. Thus, normalization of lymphoid cell fatty acid composition by LCR parallels the preservation of mitogenic responsiveness to Con A.
Protein kinase C‐dependent stimulation of phospholipase D in phospholipase C‐treated fibroblasts
Authors: Kiss Zoltan , Garamszegi Nandor
Published: November 2006

Treatment of [14C]choline‐ or [14C]ethanolamine‐labeled NIH 3T3 fibroblasts withBacillus cereus phosphatidylcholine‐specific phospholipase C (PLC) enhanced phospholipase D (PLD)‐mediated hydrolysis of the respective14C‐labeled phospholipids. PLD activity was stimulated by 1.5 U/mL of POLC and by 100 nM of the protein kinase C (PKC) activator phorbol 12‐myristate 13‐acetate (PMA) to similar extents. Treatment of14C]palmitic acid‐labeled fibroblasts with PLC in the presence of ethanol also enhanced PLD‐mediated formation of phosphatidylethanol; the effects of PLC and PMA were nonadditive. PLC had no effect on PLD activity in fibroblasts in which PKC was down‐regulated by prolonged (24 h) treatment with 300 nM PMA. These data indicate that treatment of fibroblasts with exogenous PLC results in PKC‐dependent activation of PLD.
Effect of clofibric acid on the turnover of the fatty acid‐binding protein identified in cultured endothelial cells from bovine aorta
Authors: Robers Markus , Loddenkötter Brigitte , Kresse Hans , Spener Friedrich
Published: November 2006

Several types of fatty acid‐binding proteins are found in mammalian cells. Cultured endothelial cells from bovine aorta were shown to contain exclusively the cardiac‐type fatty acid‐binding protein (cFABP) with a mean concentration of 90 ng cFABP/mg extract protein. Only small variations were observed from passage to passage. In pulse‐chase labeling experiments with L‐[35S]methionine, a half‐life of 4.0 d was measured for cFABP which is about two times longer than the average half‐life of the extracted proteins. These data imply that in aortic endothelial cells cFABP is not subject to short‐term regulation. However, addition of clofibric acid to the culture medium led to a shortening of the half‐life of cFABP, which was compensated for by an increase in its biosynthesis. The turnover of the bulk of extract proteins remained unchanged when the cells were challenged with clofibric acid.
Structure‐function relationships of alkyl‐lysophospholipid analogs in selective antitumor activity
Authors: Vogler William R. , Olson Anita C. , Hajdu Joseph , Shoji Mamoru , Raynor Robert , Kuo J. F.
Published: November 2006

This investigation was initiated in order to delineate the structure‐function relationship of the anticancer alkyllysophospholipids and assess their degree of selective cytotoxicity toward neoplastic cells. A series of glycerol phosphocholine analogs with varying substitutions in thesn‐1 andsn‐2 position were tested for their inhibitory activity as measured by thymidine incorporation, clonogenic assays and effects on protein kinase C activity against a series of human leukemic cell lines and healthy bone marrow progenitor cells. The IC50 was determined for each of the compounds in each cell line and healthy bone marrow cells following a 4‐h incubation. The data indicated that a 16–18 carbon chain at thesn‐1 coupled with a short substitution atsn‐2 had the broadest antitumor activity and was the least toxic to normal bone marrow cells. The results provide a number of useful leads toward the design and development of potentially more active phospholipid compounds.
Interrelationship of stearic acid content and triacylglycerol composition of lard, beef tallow and cocoa butter in rats
Authors: Monsma Cathy C. , Ney Denise M.
Published: November 2006

We investigated modes whereby stearic acid (18∶0) exerts a neutral or cholesterol‐lowering effect using dietary fats which provided graded levels of 18∶0 and distinct triacylglycerol (TAG) profiles. Male Sprague‐Dawley rats (150–175 g) were fed diets containing 0.2% cholesterol and 16% fat from corn oil, or from 1% corn oil plus 15% lard (13.2% 18∶0), beef tallow (19.2% 18∶0) or cocoa butter (34.7% 18∶0) for 3 wk, and then killed in a fasted or fed state. Chylomicron (CM) fatty acid profiles suggested reduced absorption of 18∶0 with greater 18∶0 intake. CM TAG profiles indicated a reduction or loss of two TAG species compared to the TAG profiles of the stearate‐rich diets: 1‐palmitoyl‐2‐oleoyl‐3‐stearoyl glycerol (POS) and 1,3‐distearoyl‐2‐oleoyl glycerol (SOS). Hepatic total cholesterol concentrations were 54–77% lower (P<0.01) in the cocoa butter‐fed than the lard‐ and beef tallow‐fed groups. The cocoa butter group showed a significantly lower ratio of high‐density lipoprotein esterified/free cholesterol than all other groups. Hepatic stearoyl‐CoA and oleoyl‐CoA concentrations, the substrate and product for hepatic δ9 desaturase, were not significantly different for corn oil‐fed and cocoa butter‐fed groups in spite of a large difference in 18∶0 intake. These data suggest that the neutral or cholesterol‐lowering effect of 18∶0 is not due to hepatic conversion of stearic to oleic acid, and that POS and SOS are poorly absorbed from stearate‐rich dietary fats.
Radioprotection of mice by dietary squalene
Authors: Storm Heidi M. , Oh Suk Y. , Kimler Bruce F. , Norton Stata
Published: November 2006

Male C3H mice were fed a diet containing 2% squalene for 14 d prior to and 30 d subsequent to exposure to 6, 7 or 8 Gy of whole body γ‐irradiation (Cesium‐137). After 14 d on squalene‐supplemented diet, plasma and jejunal tissue squalene levels were 2X and 15X that of controls. Seven days after irradiation, total white cell counts and total lymphocyte counts were substantially depressed in a radiation dose‐dependent manner. Although counts in the squalene group were consistently (18–119%) higher than those in the corresponding dietary control group, the differences between dietary groups at any single dose were not significant. Nuclear area of villus cells in the jejunum of both dietary groups was significantly reduced (20%) by day 11 post‐irradiation but the nuclear area in squalene‐fed mice was significantly greater (15%) than in controls, before and after irradiation. There were no differences in body weight as a function of either diet or radiation dose prior to the first observations of animal lethality. Animal survival was decreased from 100 to 0% at 30 d post‐irradiation by radiation doses of 6–8 Gy, with the greatest difference between dietary groups being observed at 7 Gy (median survival times of 12 and 16 d for control and squalene groups, respectively). Overall, survival of squalene‐fed mice was significantly prolonged compared with control‐fed mice (P=0.0054 by censored multiple regression analysis). It is concluded that squalene conferred some cellular and systemic radioprotection to mice receiving these lethal whole‐body radiation doses.
Acidic hydrolysis of plasmalogens followed by high‐performance liquid chromatography
Authors: Murphy Eric J. , Stephens Ralph , Jurkowitz‐Alexander Marianne , Horrocks Lloyd A.
Published: November 2006

A simple, quantitative method for determining the plasmalogen content of small samples is reported here. The method uses the different susceptibility to acid‐catalyzed hydrolysis of the alkyl, alkenyl and acyl linkages to separate the plasmalogen subclass from the other two non‐labile subclasses. Hydrolysis of plasmenylethanolamine and plasmenylcholine was complete after 4 and 1 min of acid treatment, respectively. The acid‐catalyzed hydrolysis did not alter the phospholipid fatty acid composition, making this method useful for fatty acid compositional analysis of the plasmalogen subclass. High‐performance liquid chromatography was used for separations, and phospholipids were quantitated by assay of lipid phosphorus or by direct quantitation of peak area. Using this method, small amounts (10 nmol) of ethanolamine glycerophospholipid and choline glycerophospholipid are subjected to acid‐catalyzed hydrolysis and subsequent separation of the resulting lysocompounds obtained from plasmalogens from the more acid‐stable alkylacyl and diacyl glycerophospholipid fractions. Our values for plasmalogens from commercial preparations of choline and ethanolamine glycerophospholipids agree with literature values. The usefulness of the method is demonstrated for small glycerophospholipid samples that are equivalent to samples from cultured neural cells.
Dietary lipids modify the fatty acid composition of cartilage, isolated chondrocytes and matrix vesicles
Authors: Xu Hui , Watkins A. , Adkisson Huston D.
Published: November 2006

The effects of dietary lipids on the fatty acid composition of hyaline cartilage, epiphyseal chondrocytes (EC) and matrix vesicles (MV) were evaluated in chicks. A basal semipurified diet was fed to chicks containing one of the following lipid sources at 70 g/kg: soybean oil, butter+corn oil, margarine+corn oil or menhaden oil+corn oil (MEC). Articular and epiphyseal growth cartilage were isolated from the proximal tibiotarsus; EC and MV were subsequently released by trypsin (EC 3.4.21.4) and collagenase (EC 3.4.24.3) digestion followed by ultracentrifugation. The fatty acid composition of polar lipids in chick epiphyseal cartilage at three and six weeks, as well as articular cartilage, EC and MV at eight weeks of age revealed the presence of high levels of saturated and monounsaturated fatty acids (up to 85.5%) but low levels of n−6 polyunsaturated fatty acids (PUFA) (2.6–10.2%). Mead acid (20∶3n−9,>3%) was also present in cartilage, EC and MV lipids, and was unaffected by the dietary lipid treatments. Total n−3 PUFA concentrations were the highest in cartilage, EC and MV of chicks consuming MEC. Feeding MEC lowered the levels of 20∶4n−6 in cartilage, but increased 20∶5n−3 levels. The data are consistent with those reported previously which showed that cartilage tissues are low in n−6 PUFA and that they contain 20∶3n−9. We furthermore demonstrated that the PUFA composition of cartilage can be modified by dietary lipids.
Fatty acid composition of lung, macrophage and surfactant phospholipids after short‐term enteral feeding with n−3 lipids
Authors: Palombo John D. , Lydon Erin E. , Chen Pei‐Linn , Bistrian Bruce R. , Forse R. Armour
Published: November 2006

Utilization of enteral feeding modalities may prove clinically relevant for rapid modulation of lung phospholipid polyunsaturated fatty acids (PUFA) that serve as substrates for the formation of vasoactive dienoic eicosanoids. We compared the effects of short‐term enteral feeding with formulations enriched with either fish (n−3) or corn (n−6) oil PUFA on the fatty acid composition of rat lung, alveolar macrophage and surfactant phospholipids. The diets were infused continuously for 72 h through a surgically placed gastroduodenal feeding catheter by a syringe pump. The n−3 PUFA derived from the fish oil enriched diet were readily incorporated into the phospholipid membranes of the alveolar macrophages, lung tissue and pulmonary surfactant. The relative percentages of the n−3 PUFA were significantly higher and individual and total n−6 PUFA significantly lower in the macrophage, lung and surfactant phospholipids from the n−3‐supplemented rats in comparison with those present in the rats infused enterally with the n−6 diet or untreated, chow‐fed rats (baseline). In contrast, there was a significant increase in linoleic acid (18∶2n−6) without modification of arachidonic acid (20∶4n−6) in the alveolar macrophages, lung tissue and surfactant from rats enterally receiving the n−6 diet relative to levels measured in the rats at baseline. The results suggest that short‐term continuous delivery of n−3‐enriched enteral preparations can foster rapid modification of membrane phospholipid PUFA composition of lung tissue, alveolar macrophages and lung surfactant. Utilization of similar infusion modalities to deliver n−3‐enriched enteral formulations may prove beneficial to critically ill or postoperative patients with persistent lung inflammation secondary to uncontrolled formation of vasoactive eicosanoids derived from arachidonic acid.
Sterols of eustigmatophytes
Authors: Patterson G. W. , Tsitsa‐Tzardis E. , Wikfors G. H. , Ghosh P. , Smith B. C. , Gladu P. K.
Published: November 2006

The oyster cannot synthesize sterols from smaller molecules but must obtain them from its diet, which consists of detritus and small organisms, i.e., mostly single‐celled algae. Algae differ widely in their effectiveness as oyster food. Small (<5 μm) algae which are abundant in sterols and polyunsaturated fatty acids appear to be most effective. Recent studies have shown the occurrence of cholesterol in strains of the unicellular algaeTetraselmis, Chaetoceros andSkeletonema, sometimes in large quantities. In the study reported here, six isolates of a recently constructed algal class, the Eustigmatophyceae, have been examined for sterols and fatty acids by gas chromatography and gas chromatography/mass spectrometry. All strains were shown to contain cholesterol as the principal sterol. Two isolates contained large amounts of total sterol (400–1000 fg/cell), and one (Sticho 0–18) also contained large amounts of eicosapentaenoic acid (20∶5n−3). These biochemical characteristics are desirable in a potential food source for oysters.
Purification and characterization of an extracellular lipase from the fungusRhizopus delemar
Authors: Haas Michael J. , Cichowicz David J. , Bailey David G.
Published: November 2006

The complete purification and characterization of an extracellular lipase (acylglycerol acylhydrolase, EC 3.1.1.3) fromR. delemar is described. The final product was homogeneous as judged by electrophoresis in denaturing polyacrylamide gels and by isoelectric focusing, and was shown by means of an activity stain to be lipolytic. The purified enzyme had a monomer molecular weight of 30,300, an isoelectric point of 8.6, and approximately one monosaccharide moiety per molecule.N‐Terminal sequence data (28 residues) and the amino acid composition of the lipase indicated that it corresponds to the product of a lipase‐encoding cDNA previously isolated fromR. delemar. Optimal activity occurred between pH 8.0 and 8.5. The activity and stability of the enzyme were maximum at 30°C. Divalent cations were required for activity, with barium, calcium and manganese conferring maximum activity. Activation by calcium was maximal at and above 10 mM. The lipase was not inactivated by reducing agents, sodium fluoride or phenylmethlsufonyl fluoride. It was resistant toN‐ethylmaleimide, and inactivated byp‐chloromercuribenzoic acid in a manner which was not reversed by cysteine.
Reversible ATP‐dependent inactivation of adipose diacylglycerol acyltransferase
Authors: Rodriguez M. A. , Dias C. , Lau T. E.
Published: November 2006

Diacylglycerol acyltransferase from rat adipose tissue is shown to be inactivated by 30 to 40% upon incubation with adenosine 5′‐triphosphate (ATP) and Mg2+. The activity responsible for this inactivation is associated with the cytosolic fraction, specific for ATP, prevented when ATP is substituted by β,γ‐methylene‐ATP, and partially blocked by 1 mM ethylenediaminetetraacetate or 40 mM NaF, but not by inhibitors of adenosine 3′,5′‐cyclic‐monophosphate (cAMP)‐dependent protein kinase and/or protein kinase C (PKC). The cytosolic activity cannot be mimicked by (cAMP)‐protein kinase nor by PKC. Inactivated diacylglycerol acyltransferase from ATP/cytosol‐treated microsomes can be reactivated by incubation with partially purified protein phosphate from rat liver, and can be inactivated again by further addition of ATP in the presence of cytosol. The results suggest the existence in adipose tissue of a protein kinase other than cAMP‐protein kinase or PKC, which may be involved in the regulation of triacylglycerol synthesis.
Increments of dietary linoleate raise liver arachidonate, but markedly reduce heart n−6 and n−3 fatty acids in the rat
Authors: Marangoni Franca , Mosconi Cristina , Galella Gerardina , Galli Claudio
Published: November 2006

Four diets containing 20% of energy (en%) as fat and with linoleic acid contents of 1.9, 3.1, 7.7 and 10.1 en%, respectively, were fed to one‐month‐old male rats for three months. The fatty acid profiles and the levels of the major n−6 and n−3 fatty acids in the lipids of plasma, liver, heart and kidney were measured. We found that with increasing concentrations of 18∶2n−6 in the diet, linoleic acid rose in plasma and in all organs, but long‐chain n−6 and n−3 fatty acids responded differently. In liver, arachidonic acid increased and n−3 fatty acids were not significantly affected; in heart, both arachidonic and docosahexaenoic acids were progressively reduced; and in kidney, there was no change of n−6 and n−3. The results indicate that incremental changes in dietary, linoleate affect the levels of polyunsaturated fatty acids in liver and extrahepatic organs differently.
Incorporation of n−3 fatty acids of fish oil into tissue and serum lipids of ruminants
Authors: Ashes John R. , Siebert Brian D. , Gulati Suresh K. , Cuthbertson Abla Z. , Scott Trevor W.
Published: November 2006

This study examines the biohydrogenation and utilization of the C20 and C22 polyenoic fatty acids in ruminants. Eicosapentaenoic (20∶5n−3) and docosahexaenoic (22∶6n−3) acids were not biohydrogenated to any significant extent by rumen microorganisms, whereas C18 polyenoic fatty acids were extensively hydrogenated. The feeding of protected fish oil increased the proportion of 20∶5 from 1% to 13–18% and 22∶6 from 2% to 7–9% in serum lipids and there were reductions in the proportion of stearic (18∶0) and linoleic (18∶2) acids. The proportion of 20∶5 in muscle phospholipids (PL) increased from 1.5% to 14.7% and 22∶6 from 1.0% to 4.2%; these acids were not incorporated into muscle or adipose tissue triacylglycerols (TAG). In the total PL of muscle, the incorporated 20∶5 and 22∶6 substituted primarily for oleic (18∶1) and/or linoleic (18∶2) acid, and there was no consistent change in the porportion of arachidonic (20∶4) acid.
Positional analyses of triacylglycerol fatty acids in the milk fat of the antarctic fur seal (Arctocephalus gazella)
Authors: Puppione Donald L. , Kuehlthau Cindy M. , Jandacek Ronald J. , Costa Daniel P.
Published: November 2006

The positional distribution of fatty acids has been determined for the milk triacylglycerols of the Antarctic fur seal,Arctocephalus gazella. Of particular interest was the positional distribution of the polyunsaturated n−3 fatty acids in milk triacylglycerols (TG). In adipocytes of pinnipeds, TG are synthesized with the n−3 fatty acids primarily in thesn‐1,3 positions. To determine the positional distribution, extracts of enzymatically digested lipids were separated by thin‐layer chromatography, and the constituent fatty acids were separated and quantified by gas‐liquid chromatography. Monoenoic and saturated fatty acids comprised over 75% of the total, the ratio of monoenoic to saturated fatty acids being 2∶1. The percent content of the long‐chain n−3 fatty acids, 20∶5, 22∶5 and 22∶6, ranged between 15–20%. The positional analyses revealed that at thesn‐2 position of milk TG, saturated fatty acids were in excess (57%), and the content of n−3 fatty acids was less than 5%. More than 80% of the n−3 fatty acids in milk were located in thesn‐1,3 positions. The data indicate that in pinnipeds TG are synthesized in the mammary gland and adipose tissue with fatty acids having similar positional distributions.
Preparation, chromatography and mass spectrometry of cholesteryl ester and glycerolipid‐bound aldehydes
Authors: Kamido H. , Kuksis A. , Marai L. , Myher J. J. , Pang H.
Published: November 2006

To identify lipid ester core aldehydes (aldehydes still bound to parent lipid molecules) among the secondary products of peroxidation, we have prepared reference standards of cholesteryl esters, diacylglycerols and the common glycerophospholipids (GPL) containing an aldehyde function. We subjected the unsaturated lipid esters to hydroxylation with osmium tetroxide and to carbon‐carbon bond cleavage with periodic acid. The resulting aldehyde esters (mainly 5‐oxovalerates and 9‐oxononanoates of cholesterol and the glycerolipids) were isolated and purified by thin‐layer chromatography (TLC) and reverse‐phase high‐performance liquid chromatography (HPLC). Liquid chromatography/mass spectrometry (LC/MS) was used to identify the cholesteryl and other neutral lipid ester aldehydes as the dinitrophenylhydrazones (DNPH). The choline (CGPL) and ethanolamine (EGPL) glycerophospholipids containing core aldehydes were identified by fast atom bombardment mass spectrometry (FAB‐MS) and by gas chromatography/mass spectrometry (GC/MS) of the aldehyde‐containing diacylglycerol moieties following dephosphorylation with phospholipase C and preparation of the methoximes (MOX) and the trimethylsilyl (TMS) ethers. The lipid esters containing the C5 and C9 aldehydes are chemically stable compounds with excellent chromatographic properties yielding mass spectra characteristic of the parent compounds. The overall yield of the core aldehydes was 10–20% of the unsaturated starting material.
Seawater fatty acids and lipid classes in an urban and a rural Nova Scotia inlet
Authors: Parrish Christopher C. , Bodennec Guy , Macpherson Ena J. , Ackman Robert G.
Published: November 2006

Seawater samples collected in the summer of 1989 in Nova Scotia inlets were analyzed for lipid content to examine water quality. One inlet, the Northwest Arm, is located adjacent to an urban center, while the other, Ship Harbour, is located in an uninhabited area and contains three commercial mollusk farms. Lipids in the dissolved and particulate fractions were measured by Chromarod‐Iatroscan thin‐layer chromatography with flame ionization detection and by gas chromatography. Samples collected near the urban center had higher levels of particulate hydrocarbons (28±15 μg/L) than those collected in the relatively pristine environment (11±1 μg/L). The urban center samples also had higher levels of particulate free aliphatic alcohols (14±5vs. 8±1 μg/L) and free fatty acids (5±1vs.<0.5 μg/L), suggesting degradation of wax esters and other fatty acid esters. Dissolved and particulate matter fatty acids contained a higher proportion of monounsaturated acids near the urban center (33–35vs. 25–29% of the total fatty acids). The essential fatty acids 20∶5n−3 (eicosapentaenoic acid) and 22∶6n−3 (docosahexaenoic acid), presumably of algal origin, were more prominent in the pristine environment (up to 3.5%), where mollusk aquaculture is practiced. Fatty acid markers of toxic algae were virtually absent (<0.2%) in samples taken from both locations.
5c, 11c, 14c‐Eicosatrienoic acid and 5c, 11c, 14c, 17c‐eicosatetraenoic acid ofBiota orientalis seed oil affect lipid metabolism in the rat
Authors: Ikeda Ikuo , Oka Takayuki , Koba Kazunori , Sugano Michihiro , Lie Ken Jie Marcel S. F.
Published: November 2006

The effects of 5c, 11c, 14c‐eicosatrienoic acid (20∶3BSO) and 5c, 11c, 14c, 17c‐eicosatetraenoic acid (20∶4BSO), polyunsaturated fatty acids (PUFA) contained inBiota orientalis seed oil (BSO), on lipid metabolism in rats were compared to the effects of fats rich in linoleic acid (LA) or α‐linolenic acid (ALA) under similar conditions. The potential effect of ethyl 20∶4BSO as an essential fatty acid also was examined in comparison with the ethyl esters of LA. ALA and γ‐linolenic acid (GLA). BSO‐ and ALA‐rich fat decreased the concentration of plasma total cholesterol, high density lipoprotein cholesterol, triglyceride and phospholipid as compared to LA‐rich fat. BSO was more effective in reducing plasma cholesterol concentrations than was the ALA‐rich fat. Dietary BSO markedly decreased the hepatic triglyceride concentration as compared to the LA‐rich or ALA‐rich fats. Aortic production of prostaglandin I2 tended to decrease in rats fed BSO or ALA‐rich fat compared to those fed the LA‐rich fat. Adenosine diphosphate‐induced platelet aggregation was similar in the three groups. The proportion of arachidonic acid (AA) in liver phosphatidylcholine (PC) of rats fed BSO was lowest compared to that of rats fed ALA‐rich or LA‐rich fats. Administration of 20∶4BSO, ALA or GLA to essential fatty acid‐deficient rats decreased the ratio of 20∶3n−9 to AA in liver PC to the same extent; administration of LA was more effective. The results indicate that the effects of specific PUFA contained in BSO on lipid metabolism are different from those of LA and ALA. It is also suggested that 20∶4BSO may exhibit some essential fatty acid effects.
Inhibitory effect of curcumin on fatty acid desaturation inMortierella alpina 1S‐4 and rat liver microsomes
Authors: Shimizu Sakayu , Jareonkitmongkol Saeree , Kawashima Hiroshi , Akimoto Kengo , Yamada Hideaki
Published: November 2006

An extract of rhizomes ofCurcuma longta L. (turmeric) inhibited the desaturation of dihomo‐γ‐linolenic acid (DGLA) in the arachidonic acid (AA) producing fungusMortierella alpina 1S‐4. The factor responsible for this phenomenon was isolated and identified as curcumin (diferuloyl methane). Mycelial DGLA levels increased about two‐fold (22.3 mg/g dry weight) with a concomitant decrease in AA levels when the fungus was cultivated with curcumin. The 50% inhibitory concentration against Δ5 desaturase was 27.2 μM. Curcumin also inhibited rat liver microsomal Δ5 and Δ6 desaturases.
Dietary fat and fatty acids modulate cholesterol cholelithiasis in the hamster
Authors: Cohen Bertram I. , Mosbach Erwin H. , Ayyad Nariman , Miki Shigeo , McSherry Charles K.
Published: November 2006

We tested two hypotheses, i) whether the type and the amount of fat in the diet will affect the formation of cholesterol gallstones in the hamsters, and ii) whether palmitic acid, a major fatty acid component of butterfat, can act as a potentiator of cholesterol cholelithiasis in the hamster. Young, male golden Syrian hamsters (Sasco) were fed a semipurified diet containing casein, corn starch, cellulose and cholesterol (0.3%) to which various types and amounts of fat (butterfat, olive oil, menhaden oil, corn oil) were added. All diets contained 2% corn oil to supply essential fatty acids to the growing hamsters. No deaths or illness occurred during the experiment. Animals fed the semipurified diet plus 4% butterfat (group 1) had a gallstone incidence of 63%. Replacement of butterfat with either olive oil, corn oil or menhaden oil prevented the formation of cholesterol gallstones entirely (groups 2–4). When total butterfat was increased from 4% to 8% (group 8), the incidence of cholesterol gallstones increased to 80%. Substitution of 4% olive oil (group 5), corn oil (group 6), or menhaden oil (group 7) for the additional 4% butterfat significantly reduced gallstones to 35%, 45% and 30%, respectively. The replacement of 4% butterfat with 1.2% palmitic acid gave the highest incidence of cholesterol gallstones (95%). These results suggest that butterfat (and one of its components, palmitic acid) intensifies gallstone formation in this model whereas mono‐ and polyunsaturated fats act as inhibitors of cholesterol cholelithiasis. A fatty acid, possibly palmitic acid, appears to act as lithogen in our model.
Changes in blood lipids and fibrinogen with a note on safety in a long term study on the effects of n−3 fatty acids in subjects receiving fish oil supplements and followed for seven years
Authors: Saynor Reginald , Gillott Timothy
Published: November 2006

The present study was designed to assess the effectiveness of the n−3 fatty acids in modifying serum total, low density lipoprotein and high density lipoprotein (HDL) cholesterol, as well as serum triglycerides, over a seven‐year period. Changes in plasma fibrinogen were recorded and long term safety assessed. A total of 365 subjects with ischemic heart disease (IHD), hyperlipidemia or a strong family history of IHD had their diet supplemented with MaxEPA (Seven Seas Ltd., Hull, England) fish oil containing 18–19% eicosapentaenoic acid. Venous blood samples were taken at regular intervals for lipid and fibrinogen assays and routine clinical chemistry and hematological profiling. Current medication was recorded and no further dietary modification was attempted. Triglyceride and fibrinogen were significantly reduced, whereas a significant reduction in total cholesterol occurred only in the subjects with a pre‐oil level>6.5 mmol/L. HDL cholesterol significantly increased over the study period. Clinical chemistry and hematological profiles were not adversely affected, and platelet count did not change significantly. The type of lipid changes observed were those usually considered antiatherogenic. Reducing fibrinogen may result in beneficial changes in the pathological processes leading to thrombotic occlusion. The consumption of MaxEPA by our patients over a seven‐year period did not indicate any adverse effects.
Production of eicosapentaenoic acid by freshwaterVibrio
Authors: Ringø Einar , Jøstensen Jens Petter , Olsen Rolf Erik
Published: November 2006

Arctic charr,Salvelinus alpinus (L.), were fed a moist pellet diet based on casein, dextrin and coconut oil in fresh water. The diet contained substantial amounts of saturated fatty acids, especially 12∶0. Polyunsaturated fatty acids in the n−3 series were not detected in the diet, but analysis of the intestinal liquor stripped from the charr showed that eicosapentaenoic acid (EPA, 20∶5n−3) accounted for 3.5% of fatty acids in total lipid. Colony forming units (CFU) of aerobic microorganisms were approximately 104 per mL intestinal liquor. Seventeen bacterial strains isolated from the intestinal liquor were screened for EPA production. Four isolates contained a high proportion of EPA in their total lipid. These isolates belong to the speciesVibrio.
The effect of borage oil consumption on the composition of individual phospholipids in human platelets
Authors: Barre D. Edward , Holub Bruce J.
Published: November 2006

The effect of supplementation with borage oil containing γ‐linolenic acid (GLA, 18∶3n−6) on the levels and fattya cid compositions of individual human platelet phospholipids was evaluated. For this purpose, male volunteers were given an average daily intake of 5.23 g of GLA (as borage oil) for 42 days, after which the supplement was withdrawn for an additional 42‐day period. No significant differences were found in the relative amounts of the choline phospholipids (PC), ethanolamine phospholipids (PE), phosphatidylserine (PS), phosphatidylinositol (PI), and sphingomyelin (SPH) at days 0, 22, 43, 64, and 85. However, marked differences were observed in the fatty acid compositions of all the phospholipids including a marked, and reversible, rise in the level of dihomo‐γ‐linolenic acid (DGLA, 20∶3n−6), without a significant elevation in arachidonic acid (AA, 20∶4n−6) and decreases in n−3 polyunsaturated fatty acids. In the case of PC, a net rise in DGLA of 1.8 mol% was observed by day 22 (from 2.1 to 3.9 mol%). The DGLA/AA ratios at day 43 exhibited considerable variability across phospholipids with PC>PS>PE=PI; the PC, PE, PS, and PI accounted for 67.6, 16.7, 12.9, and 2.6%, respectively, of the total DGLA in platelet phospholipids. Interestingly, despite the lack of DGLA in SPH, this phospholipid exhibited a marked enrichment in nervonic acid (NA, 24∶1n−9) from 16.2 to 24.7 mol% upon borage oil consumption. The observed alterations may represent biochemical strategies for adaptation to dietary fatty acid modifications and the regulation of platelet membrane functioning.
The effect of short‐term lipid infusion on liver function and biliary secretion in rats
Authors: Rubin M. , Halpern Z. , Livoff A. , Wennberg A. , Tietz A. , Antebi E. , Lichtenberg D.
Published: November 2006

This study was undertaken to determine the effect of various lipid emulsions on the hepato‐biliary system in rats. Rats were randomly divided into six groups and infused continuously for 48 hr with either long‐chain triglycerides (LCT), medium‐chain triglycerides (MCT) or a mixture of MCT and LCT. One group infused with physiological saline solution served as controls. Throughout this period the rats received a fat free dietad libitum. During the last hour of lipid infusion bile was collected for determination of bile flow and composition. Subsequently, the rats were sacrificed and the morphology and lipid content of the liver determined. Only LCT lipid emulsions induced morphological changes and increased liver cholesterol content. In two rats infused with radiolabeled LCT, no labeled cholesterol was found in the liver, indicating that the excess hepatic cholesterol level may originate from enhanced cholesterol mobilization to the liver. Biliary cholesterol and phospholipid concentrations in LCT‐treated rats were also elevated, as was the lithogenic index, whereas the other emulsions had no such effects. None of the emulsions affected the plasma liver function tests or bile flow. We therefore conclude that the lithogenicity of the bile in rats is directly related to the lipid components of the total parenteral nutrition and the type of triglyceride infused.
Derivatives of Di‐O‐octanoylglycerol and mono‐O‐octylglycerol as modulators of protein kinase C and diacylglycerol kinase activities
Authors: Goddat Jacqueline , Coste Hervé , Vilgrain Isabelle , Chambaz Edmond , Driguez Hugues
Published: November 2006

Twelve analogs of 1,2‐di‐O‐octanoylglycerol modified at C‐3 and three quaternaryN‐alkyl‐ammonium derivatives of glycerol were synthesized. The compounds were testedin vitro as potential modulators of the calcium activated, phospholipid dependent protein kinase C (PKC) and diacylglycerol (DAG) kinase activities in order to understand the molecular interactions of these enzymes with their natural activators, inhibitors, or substrates. PKC activity was assayed by measuring histone H1 phosphorylation, and the compounds synthesized were tested either in the presence (inhibitors) or in the absence (activators) of 1,2‐di‐O‐octanoyglycerol analogs with the phosphatidylserine/Ca2+ mixture. DAG kinase activity was measured by the incorporation of phosphate into 1,2‐di‐O‐oleoyl‐sn‐glycerol in the presence of the various analogs synthesized. In regard to PKC activity, the assays revealed that 1,2‐di‐O‐octanoylglycerol analogs are inactive when modified at C‐3 with groups which do not permit hydrogen bonding. Under our conditions, di‐O‐octanoylthioglycerol, which has been reported as inactive, was able to activate PKC in the presence of phosphatidylserine. It has been shown to give a synergistic activation with diacylglycerol and had no affinity for the phorbol ester receptor binding site, suggesting thatO‐octanoylthioglycerol interacts with the enzyme at a different site from the phorbol ester receptor binding site. PKC and DAG kinase activities are inhibited byN‐alkyl‐ammonium compounds (IC50 24 μM) only when either two 8‐carbon alkyl or acyl chains are present at the 1‐ and 2‐positions of the glycerol backbone. The fact that these compounds have a strong effect on the binding of [3H]phorbol 12,13‐dibutyrate to protein kinase C, and also inhibit DAG kinase, may suggest binding to the DAG site of the regulatory domain of PKC.
Effect of prenatal and postnatal exposure to ethanol on rat central nervous system gangliosides and glycosidases
Authors: Prasad V. V. T. S.
Published: November 2006

We investigated the effect of maternal alcohol consumption on cell number, gangliosides and ganglioside catabolizing enzymes in the central nervous system (CNS) of the offspring. Virgin female rats of the Charles Foster strain were given 15% (v/v) ethanol in drinking water one month prior to conception and during gestation and lactation. At 21 days postnatal age, the offspring were sacrificed and the brains were separated into cerebrum, cerebellum and brain stem to investigate possible regional variations. Compared to controls, wet weight of cerebrum, cerebellum and brain stem, and of spinal cord was decreased in the pups exposed to alcohol. DNA and protein contents were also found to be lowered in all the CNS regions of the pups exposed to alcohol. Conversely, maternal alcohol consumption was found to increase the concentration and the content of total gangliosideN‐acetylneuraminic (NANA) in CNS of the pups. In addition, alcohol treatment was found to induce alterations in the proportions of individual ganglioside fractions. Interestingly, these alterations are somewhat different than those observed in the neonatal brain and spinal cord of the pups subjected to prenatal alcohol exposure. The alterations in the proportions of ganglioside fractions were shown to be region‐specific. Maternal alcohol consumption resulted in decreased activities of sialidase, β‐galactosidase, β‐glucosidase and β‐hexosaminidase. The results suggest that the alcohol‐associated increases in ganglioside concentration may be at least partly due to the decreased activities of ganglioside catabolizing enzymes.
Fluorospectroscopic analysis of the fluorescent substances in peroxidized microsomes of rat liver
Authors: Minamide Yoshiyuki , Horie Toshiharu , Awazu Shoji
Published: November 2006

The fluorescent substances formed in rat liver microsomes in the course of lipid peroxidation were investigated by fluorescence techniques. The fluorescence emitted from peroxidizing microsomes continuously increased as lipid peroxidation progressed, while the steady‐state fluorescence anisotropy increased and then reached a plateau. A similar increase was observed in the steady‐state fluorescence anisotropy of 1,6‐diphenyl‐1,3,5‐hexatriene in peroxidizing microsomes. The fluorescence from peroxidized microsomes consisted of at least three species having short, middle or long fluorescence lifetimes. The lifetimes and relative amplitudes of fluorescence were unaffected by the extent of lipid peroxidation. Both fluorescence of the chromolipids extracted and the proteins isolated from peroxidized microsomes had the same characteristics in fluorescence lifetimes as the fluorescence from whole peroxidized microsomes. Thus, these lipids and proteins appear to be the major biological substances responsible for the fluorescence emanating from whole peroxidized microsomes. Furthermore, fluorescent substances formed in microsomes seem to increase in quantity rather than change in quality as lipid peroxidation progresses.
A study of the composition of fish liver and body oil triglycerides
Authors: McGill Alister S. , Moffat Colin F.
Published: November 2006

Silver‐ion high‐performance liquid chromatography (Ag+‐HPLC) was used to study the range and variations in molecular species of triglycerides from industrial, retail and laboratory extracted fish oils. These were contrasted with a typical plant oil. Selected fish oils were fractionated and the fatty acid distribution of the fractions determined by gas‐liquid chromatography. Fish oils gave a characteristic Ag+‐HPLC profile, typified by sharp, intense peaks at the start of the chromatogram and broad, multiple nongaussian peaks for the late eluting components. Triglycerides ranging from those that were wholly saturated to those containing 16 double bonds were isolated. Cod (Gadus spp.), saithe (Pollachius virens) and monkfish (Squatina squatina) liver oils gave similar triglyceride profiles. Mackerel (Scomber scombrus), capelin (Mallotus villosus) and herring (Clupea harengus) body oils gave characteristic triglyceride profiles which were associated with high concentrations of 20∶1 and 22∶1 fatty acids. Only small amounts of these particular triglycerides were observed for menhaden (Brevoortia spp.), South African anchovy (Engraulis capensis) and Indian sardine (Sardinella longiceps) oils, all of which contained minor amounts of these acids. The latter oils contained highly unsaturated triglycerides, whereas only traces of these were noted for the former. Chromatography with Ag+‐HPLC can be used for the rapid screening of fish oils and for selecting those oils rich in polyunsaturated acids that may be suitable for enrichment. Cottonseed oil gave well‐defined and discrete peaks. Similar peaks were observed in the chromatogram of Omega‐combination, a mixture of primrose and fish oils. Thus, fish, plant and a mixture of these oils can be readily distinguished.