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PubMedDate not supplied

Cyclic vs continuous enteral feeding with omega-3 and gamma-linolenic fatty acids: effects on modulation of phospholipid fatty acids in rat lung and liver immune cells.

UNLABELLED: Arachidonic acid (AA) present in lung and liver immune cell phospholipids is the precursor of eicosanoids that promote neutrophil margination, leading to tissue injury and inflammation. Administration of novel enteral formulations low in linoleic acid (LA) and containing eicosapentaenoic acid (EPA) from fish oil and gamma-linolenic acid (GLA) from borage oil displaces AA and promotes cell formation of eicosanoids with reduced inflammatory potential. The present study was undertaken to determine whether or not short-term provision of enteral diets containing GLA, EPA, or both in a cyclic fashion modulated the fatty acid composition of rat alveolar macrophage (AM) and liver Kupffer and endothelial (K&E) cell phospholipids in vivo to the extent achieved during continuous feeding. METHODS: Rats were isocalorically fed through a gastrostomy catheter for 3 or 6 days with high-fat, low-carbohydrate diets that were enriched with either LA (diet A), EPA (diet B), or EPA + GLA (diet C). The rats were randomized by infusion modality, ie, continuous vs cyclic (14 hours feeding with 10 hours fasting daily) feeding. AM and K&E were isolated and phospholipid fatty acid profiles were determined by gas chromatography. RESULTS: The dietary effects on AM and K&E cell phospholipid fatty acids for a given feeding period were not significantly influenced by the infusion modality. AM and K&E cells from rats receiving either diet B or diet C for 3 days had significantly lower AA and LA and higher EPA and dihomo-GLA (DHGLA), respectively, than rats given diet A regardless of the infusion modality. The mole % of EPA and DHGLA in K&E cells were higher after 6 vs 3 days of cyclic feeding with diet C. Using the eicosanoid precursor ratio (EPA + DHGLA/AA), the potential for generation of AA-derived eicosanoids was lower in rats given die B or C vs diet A regardless of infusion modality. DISCUSSION: Given the rapid changes in lung and liver immune cell phospholipid fatty acids, short-term provision of EPA and GLA-enriched diets cyclically or continuously may prove clinically relevant for modulating the fatty acid composition and potential eicosanoid formation by these cells.

Adipose Tissue↗
PubMed2005

A gas chromatography/electron ionization-mass spectrometry-selected ion monitoring method for determining the fatty acid pattern in food after formation of fatty acid methyl esters.

A method using gas chromatography/electron ionization-mass spectrometry (GC/EI-MS) in the selected ion monitoring (SIM) mode was developed for the analysis of fatty acids as methyl esters (FAMEs) in order to determine their percentage contribution to the fatty acid profile in food. In the GC/EI-MS-SIM mode, saturated fatty acids were determined with m/z 87, monoenoic fatty acids were determined with m/z 74, and polyenoic fatty acids were determined via the sum of m/z 79 and m/z 81. The ratios of these fragment ions and the GC retention data provided additional information for tentative structural assignments. The 28 FAME standards tested provided similar results for the novel GC/EI-MS-SIM method and GC/EI-MS in the full scan mode, both of which were slightly worse than GC/flame ionization detection (FID). Analysis of sunflower oil, suet, and cod liver oil verified that both major and minor fatty acids (20-60% and down to 0.001% contribution to the fatty acid pattern) were determined with sufficient quality that justifies application of the GC/EI-MS-SIM method for the analysis of food samples. Furthermore, the method was approximately 20- or approximately 10-fold more sensitive than GC/EI-MS in the full scan mode or GC/FID, respectively. The method is suited for both quantitative purposes and fatty acid identification in samples where only low amounts of lipids are available.

Chromatography, Gas↗
PubMed1983

Fatty acid composition and primer specificity of de novo fatty acid synthetase in Bacillus globispores, Bacillus insolitus, and Bacillus psychrophilus.

The fatty acid compositions of three psychrophilic species of Bacillus were determined by gas--liquid chromatography. The proportions of straight-chain fatty acids, branched-chain fatty acids, and unsaturated fatty acids were found to be 13.3, 86.7, and 26.1% of the total cellular fatty acids for Bacillus globispores, 36.6, 63.4, and 25.1% for Bacillus insolitus, and 6.9, 93.1, and 18.4% for Bacillus psychrophilus, respectively. In all three organisms the de novo fatty acid synthetase specificity towards acyl-CoA primers was butyryl-CoA greater than propionyl-CoA much greater than acetyl-CoA. This shows that B. insolitus, which has an unusually large proportion of straight-chain fatty acids for Bacillus, does not possess a different de novo fatty acid synthetase than the other two organisms. Therefore, the greater proportion of straight-chain fatty acids in B. insolitus may be explained by a large supply of straight-chain primer.

Acyl Coenzyme A↗
PubMed1997

The fatty acid composition of a Vibrio alginolyticus associated with the alga Cladophora coelothrix. Identification of the novel 9-methyl-10-hexadecenoic acid.

The fatty acid composition of a new strain of Vibrio alginolyticus, found in the alga Cladophora coelothrix, was studied. Among 38 different fatty acids, a new fatty acid, 9-methyl-10-hexadecenoic acid and the unusual 11-methyl-12-octadecenoic acid, were identified. Linear alkylbenzene fatty acids, such as 10-phenyldecanoic acid, 12-phenyldodecanoic acid and 14-phenyltetradecanoic acid, were also found in V. alginolyticus. The alga contained 43% saturated fatty acids, and 28% C16-C20 polyunsaturated fatty acids of the n-3 and n-6 families.

Chlorophyta↗
PubMed1978

Effects of essential fatty acid deficiency on prostaglandin synthesis and fatty acid composition in rat renal medulla.

Studies are reported on the capacity of isolated rat renal papilla (inner medulla) to synthesize and release prostaglandin (PG) E from endogenous and exogenous precursor(s) during development of an essential fatty acid (EFA) deficiency in the rat. Weanling (21-day-old) male Sprague-Dawley rats were fed a fat-free diet supplemented with either 5% hydrogenated coconut oil (HCO) or 5% safflower oil (SO). At approximately 3, 6 and 7 weeks (6. 9 and 10 weeks of age), groups of animals fed each diet were killed for studies of PGE synthesis in the renal papillae. Differences in the fatty acid composition of the papillae lipids of the animals of each group were also determined. The in vitro production of PGE from endogenous precursor(s) was significantly reduced in the papillae from the 6-week-old rats fed the HCO diet compared to the control (SO) rats, and appeared to be near maximally depressed in the 10-week-old animals compared to that of animals fed an EFA deficient diet for over a year in an accessory experiment. Analyses of the fatty acids of the papillae lipids of the HCO groups showed that the levels of 18:2 and 20:4 were markedly reduced, and those of 16:1, 18:1 and 20:3 were elevated compared to the controls even in the 6-week-old animals, typical of an EFA deficiency. The papillae lipids of the animals fed the HCO diet were also depleted of their stores of 22:4 omega 6. A fatty acid believed to be derived by chain elongation of 20:3 omega 9, 22:3, was found in large concentrations in the papillae triglycerides of the EFA deficient rats. Incubations of exogenous arachidonic acid (20:4) in homogenates and tissue slices of the papillae of the HCO dietary groups showed that the PG synthetase was not impaired by an EFA deficiency. The rate of PGE synthesis in the papillae of the EFA deficient animals was generally enhanced when exogenous 20:4 was added, indicating that the concentration of available precursor(s) is a primary factor in the control of PGE synthesis in the papilla of the rat.

Animals↗
PubMed1989

Direct transesterification of plasma fatty acids for the diagnosis of essential fatty acid deficiency in cystic fibrosis.

This study was aimed at redefining criteria for essential fatty acid (EFA) deficiency with the use of the direct transesterification procedure (1986. J. Lipid Res. 27: 114-120) and at determining whether a simple assay of total fatty acids (FA) is as predictive of EFA deficiency as the FA pattern from plasma, red cell, and platelet phospholipids. Fasting blood samples were taken from 163 cystic fibrosis (CF) patients who were encouraged to consume 35-40% of their calories as fat. Their mean (+/- SD) age was 9.6 +/- 4.8 yr. The control group consisted of 44 unaffected siblings aged 13.1 +/- 3.1 yr. The 20:3(n-9)/20:4(n-6) ratio in 77 (47%) CF children was more than 2 SD above the values (mean +/- SD) of 0.021 +/- 0.007 obtained in the 44 controls. Groups of EFA-sufficient (n = 10) and EFA-deficient (n = 7) subjects were selected for further studies. The plasma total FA 20:3(n-9)/20:4(n-6) ratios of 0.029 +/- 0.003 in EFA-sufficient and of 0.216 +/- 0.103 in EFA-deficient was as good a discriminant as FA in phospholipids from plasma, red cell PC, and platelets. Among the 21 individual fatty acids, 20:3(n-9), which was also found in controls, and 16:1(n-7) (palmitoleic) proved to be the most sensitive indices of EFA deficiency. They are equally reliable in plasma, red cells, and platelets, but the inverse linear relationship (r = -0.91) between the n-7 family and 18:2(n-6) proved to be more closely associated with EFA deficiency than the one (r = 0.66) between 20:3(n-9) and 20:4(n-6).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1999

Melittin enhances amino acid and free fatty acid release from the in vivo cerebral cortex.

The effects of the phospholipase activator melittin on amino acid and free fatty acid release from the rat cerebral cortex were monitored and compared with those of a secretory PLA(2), using a cortical cup technique with topical application of these agents in artificial cerebrospinal fluid. Melittin (10 microg/ml; 3.5 microM) elicited a rapid increase in the levels of superfusate amino acids; aspartate, glutamate, GABA, glycine, taurine, glutamine, phosphoethanolamine, alanine, serine and the free fatty acids arachidonic, linoleic, palmitic and oleic acid. PLA(2) (25 microg/ml) also enhanced amino acid efflux but its effects were significantly slower to develop than those of melittin. The results confirm previous indications of an ability of phospholipases to augment extracellular levels of several amino acids, including the excitotoxins glutamate and aspartate, and further implicate phospholipase activation as a significant contributor to cerebral ischemic injury. Melittin has the potential to be a useful tool with which to evaluate the role of phospholipases in ischemia injury.

Amino Acids↗
PubMed2005

Quantification of primary fatty acid amides in commercial tallow and tallow fatty acid methyl esters by HPLC-APCI-MS.

Primary fatty acid amides are a group of biologically highly active compounds which were already identified in nature. Here, these substances were determined in tallow and tallow fatty acid methyl esters for the first time. As tallow is growing in importance as an oleochemical feedstock for the soap manufacturing, the surfactant as well as the biodiesel industry, the amounts of primary fatty acid amides have to be considered. As these compounds are insoluble in tallow as well as in the corresponding product e.g. tallow fatty acid methyl esters, filter plugging can occur. For the quantification in these matrices a purification step and a LC-APCI-MS method were developed. Although quantification of these compounds can be performed by GC-MS, the presented approach omitted any derivatization and increased the sensitivity by two orders of magnitude. Internal standard calibration using heptadecanoic acid amide and validation of the method yielded a limit of detection of 18.5 fmol and recoveries for the tallow and fatty acid methyl ester matrices of 93% and 95%, respectively. A group of commercially available samples were investigated for their content of fatty acid amides resulting in an amount of up to 0.54%m/m (g per 100 g) in tallow and up to 0.16%m/m (g per 100 g) in fatty acid methyl esters.

Amides↗
PubMed2002

Nutrient and fatty acid deposition in broilers fed different dietary fatty acid profiles.

The aim of this study was to determine the effect of different dietary fatty acid profiles on efficiency of energy, fat, nitrogen, and fatty acid deposition in broiler chickens. Sixty female broiler chickens were fed a basal diet without additional fat or with 4 other diets with different fats (tallow, olive, sunflower, and linseed oils) at 10% from 28 to 48 d of age. Among broilers fed diets with added fat, those fed linseed oil had less abdominal fat (in grams and percentage) than those fed tallow (P < 0.05). Absorbed fat losses were slightly higher for birds fed linseed oil, and nitrogen efficiency was lower in those fed tallow (P < 0.05). However, there were not significant differences in energy deposition among broilers fed diets with added fat. Fatty acid balance showed the highest values of fatty acid oxidation during the experimental period in broilers fed linseed oil (48.2 g), followed by those fed sunflower oil (23.2 g). Contribution of endogenous fat synthesis to total body fat deposition was minimal in birds fed diets with added fat accounting for 3, 1.2, 8.5, and 7.5 g for broilers fed tallow, olive, sunflower, and linseed oils, respectively. This reflects lipogenesis inhibition by dietary fat addition. Interestingly, between broilers fed diets with added fat, higher values of fatty acids from endogenous synthesis were found in broilers fed diets rich in polyunsaturated fatty acids (PUFA). Results suggest that reduction of abdominal fat in broilers fed linseed oil seems to be a consequence of higher lipid oxidation despite the higher synthesis of endogenous fatty acids.

Absorption↗
PubMed1989

Specific high affinity binding of lipoxygenase metabolites of arachidonic acid by liver fatty acid binding protein.

Liver fatty acid binding protein (L-FABP) binds avidly the arachidonic acid metabolites, hydroperoxyeicosatetraenoic acids (HPETEs) and hydroxyeicosatetraenoic acids (HETEs). Binding of 15-[3H]HPETE was specific, saturable, reversible, and rapid. Protein specificity was indicated by the following order: L-FABP greater than bovine serum albumin greater than ovalbumin = beta-lactoglobulin greater than ribonuclease. Ligand specificity was evidenced by the following order of apparent competition: 15-HPETE greater than or equal to 5-HETE greater than or equal to 5-HPETE = oleic acid greater than 12-HETE greater than 12-HPETE greater than or equal to 15-HETE greater than prostaglandin E1 much greater than leukotriene C4 greater than prostaglandin E2 much greater than thromboxane B2 = leukotriene B4. Once bound, 15-HPETE was reversibly displaced. Ligand was recovered from the protein complex and confirmed to be 15-[3H]HPETE by TLC. L-FABP bound HPETE with a dissociation constant of 76 nM,5-HETE at 175 nM, and 15-HETE at 1.8 microM, and the reference fatty acids oleic acid at 1.2 microM and arachidonic acid at 1.7 microM. Thus, the affinity was approximately 16-fold greater for 15-HPETE, and 7-fold higher for 5-HETE, than for oleic acid. The need exists for studies of complexes of L-FABP with the HPETEs and HETEs in hepatocytes, especially since L-FABP has previously been associated with mitosis in normal hepatocytes, and shown to be the target protein of two liver carcinogens, and these arachidonic acid metabolites have been found to be able to modulate activities related to cell growth.

Animals↗
PubMed1996

Effect of surface and intracellular pH on hepatocellular fatty acid uptake.

Fatty acids enter hepatocytes, at least in part, by a carrier-mediated uptake mechanism. The importance of driving forces for fatty acid uptake is still controversial. To evaluate possible driving mechanisms for fatty acid transport across plasma membranes, we examined the role of transmembrane proton gradients on fatty acid influx in primary cultured rat hepatocytes. After hepatocytes were loaded with SNARF-1 acetoxymethyl ester, changes in intracellular pH (pHi) under different experimental conditions were measured and recorded by confocal laser scanning microscopy. Fatty acid transport was increased by 45% during cellular alkalosis, achieved by adding 20 mM NH4Cl to the medium, and a concomitant paracellular acidification was observed. Fatty acid uptake was decreased by 30% during cellular acidosis after withdrawal of NH4Cl from the medium. Cellular acidosis activates the Na+/H+ antiporter to export excessive protons to the outer cell surface. Inhibition of Na+/H+ antiporter activity by amiloride diminishes pHi recovery and thereby accumulation of protons at the outer surface of the plasma membrane. Under these conditions, fatty acid uptake was further inhibited by 57% of control conditions. This suggests stimulation of fatty acid influx by an inwardly directed proton gradient. The accelerating effect of protons at the outer surface of the plasma membrane was confirmed by studies in which pH of the medium was varied at constant pHi. Significantly higher fatty acid influx rates were observed at low buffer pH. Recorded differences in fatty acid uptake appeared to be independent of changes in membrane potential, because BaCl2 did not influence initial uptake velocity during cellular alkalosis and paracellular acidosis. Moreover, addition of oleate-albumin mixtures to the NH4Cl incubation buffer did not change the observed intracellular alkalinization. In contrast, after cells were acid loaded, addition of oleate-albumin solutions to the recovery buffer increased pHi recovery rates from 0.21 +/- 0.02 to 0.36 +/- 0.05 pH units/min (P < 0.05), indicating that fatty acids further stimulate Na+/H+ antiporter activity during pHi recovery from an acid load. It is concluded that carrier-mediated uptake of fatty acids in hepatocytes follows an inwardly directed transmembrane proton gradient and is stimulated by the presence of H+ at the outer surface of the plasma membrane.

Animals↗
PubMed2006

Comparative studies of some phenolic compounds (quercetin, rutin, and ferulic acid) affecting hepatic fatty acid synthesis in mice.

The physiological activities of some phenolic compounds affecting hepatic fatty acid synthesis in mice were compared. Male ICR mice were fed an experimental diet containing 1% quercetin dihydrate, rutin, or ferulic acid or a control diet free of phenolic compounds for 15 days. Quercetin significantly lowered serum cholesterol and phospholipid levels in mice. Also, the serum triacylglycerol level was considerably lower in mice fed the quercetin-containing diet than in those fed a diet free of phenolic compounds, although the difference was not significant. Rutin and ferulic acid did not affect these parameters. Quercetin significantly reduced the activity and mRNA levels of various enzymes involved in hepatic fatty acid synthesis. Rutin reduced a few of the parameters for lipogenesis, but ferulic acid did not affect any of the parameters. It was suggested that a reduction in hepatic lipogenesis is the mechanism underlying the hypolipidemic effect of quercetin.

ATP Citrate (pro-S)-Lyase↗