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PubMed2001

Lipid remodeling in mouse liver and plasma resulting from delta6 fatty acid desaturase inhibition.

Electrospray/tandem mass spectrometry was used to quantify lipid remodeling in mouse liver and plasma during inhibition of polyunsaturated fatty acid synthesis by the delta6 fatty acid desaturase inhibitor, SC-26196. SC-26196 caused increases in linoleic acid and corresponding decreases in arachidonic acid and docosahexaenoic acid in select molecular species of phosphatidylcholine, phosphatidylethanolamine, and cholesterol esters but not in phosphatidylserine, phosphatidylinositol, or triglycerides. For linoleic acid-, arachidonic acid-, and docosahexaenoic acid-containing phospholipid species, this difference was, in part, determined by the fatty acid at the sn-1 position, namely, palmitic or stearic acid. An understanding of phospholipid remodeling mediated by delta6 desaturase inhibition should aid in clarifying the contribution of arachidonic acid derived via de novo synthesis or obtained directly in the diet during inflammatory responses.

Animals↗

PubMed1979

Positional distribution of exogenous and endogenous fatty acids in triacylglycerols formed by rat adipocytes in vitro.

Rat adipocytes were used in vitro to compare the positional distributions of fatty acids of intra- and extra-cellular origin in triacyl-sn-glycerols. Fatty acids of extracellular origin were esterified to each position in similar, but not identical, proportions to the natural distributions. A high proportion of the oleic acid synthesised in the tissue by desaturation of exogenous stearic acid was found in position sn-3. When palmitic acid was the only fatty acid added, tripalmitoylglycerol was synthesised by the adipocytes. The rate and pattern of fatty acids synthesised de novo from acetate was dependent on the age of the donor rat and the concentration of acetate and presence or absence of long-chain fatty acids in the medium. The newly synthesised fatty acids were esterified in very different proportions from the natural distributions and thus from those of extracellular fatty acids. The results are discussed in terms of esterification of the fatty acids from the two sources in different compartments of the cell.

Adipose Tissue↗

PubMed1982

Plasma and erythrocyte membrane fatty acids in oral contraceptive users.

The fatty acid composition of the plasma choline phosphoglycerides (CPG) and erythrocyte phospholipids were determined in women using oral contraceptive agents and age-matched female controls. Those using oestrogen and progestogen combined preparations had higher concentrations of palmitic acid (16:0) and linoleic acid (18:2 omega 6) and lower concentrations of stearic acid (18:0) and long chain polyunsaturated fatty acids (LCP), in particular arachidonic acid (20:4 omega 6) and eicosapentaenoic acid (20:5 omega 3), in their plasma CPG than controls. These differences were reflected in the erythrocyte phospholipids. The progestogen-only group had similar concentrations to matched controls. It is suggested that the lower concentrations of LCP in combined pill users may affect membrane function and prostaglandin synthesis and may relate to their increased risk of thrombosis.

Adolescent↗

PubMed1993

Effect of a high fat diet on phospholipid class distribution and fatty acid composition in rat liver.

1. Long term consumption (20 weeks) of a high fat diet (65% of the energy content as fat) rich in either saturated [30% (w/w) coconut oil] or unsaturated [30% (w/w) sunflower oil] fatty acids resulted in strikingly similar alterations in the phospholipid class distribution and fatty acid composition in the liver of male Wistar rats. 2. The effect of these two diets was compared to a control group maintained on a 2% fat diet (w/w) for the same time interval. 3. In spite of the difference in the PUFA/SFA (polyunsaturated fatty acid/saturated fatty acid) ratio between the two high fat diets (0.1, saturated fatty acid diet; 5.4, unsaturated fatty acid diet), both diets resulted in a similar PUFA/SFA ratio in liver phospholipids, a similar reduction in palmitic acid (16:0), oleic acid (18:1, n-9) and arachidonic acid (20:4, n-6) and an elevation in stearic acid (18:0), linoleic acid (18:2, n-6) and docosahexaenoic acid (22:6, n-3). 4. Further, changes in the phospholipid classes were also similarly affected by both high fat diets.

Animals↗

PubMed2000

Adipose differentiation related protein: expression, purification of recombinant protein in Escherichia coli and characterization of its fatty acid binding properties.

Adipose differentiation related protein (ADRP) is a 53 kDa protein encoded by a cDNA originally cloned by differential hybridization from murine adipocytes. ADRP is induced during the early onset of the adipose differentiation program and is expressed at high level in mature adipocytes. We have demonstrated that ADRP stimulated the uptake of fatty acids thereby providing evidence for a functional role of ADRP in lipid metabolism. In the present paper, the murine ADRP has been expressed as a recombinant histidine-tagged protein in Escherichia coli, and purified from expressing cultures in order to examine its biochemical properties. We report here that the purified recombinant ADRP binds fatty acids and exhibits stoichiometric saturable binding of NBD-stearic acid with a K(d)=0.145+/-0.003 microM and a B(max)=0.99+/-0.05. Analysis of fluorescence emission spectra indicates that the polarity of the ADRP binding site is near epsilon approximately 23, close to that observed for fatty acid binding sites in other lipid binding proteins such as the liver fatty acid binding protein. The data presented here provide evidence that isolated ADRP purified in the experimental conditions described here can be used for functional studies.

4-Chloro-7-nitrobenzofurazan↗

PubMed1997

Trimetazidine increases phospholipid turnover in ventricular myocyte.

Trimetazidine (TMZ) is an anti-ischemic compound devoid of hemodynamic effects. It was recently suggested to induce cardiomyocyte protection by a mechanism involving lipid metabolism. The effects of TMZ were evaluated in rats on cardiac lipid composition, and in cultured rat cardiomyocytes on phospholipid metabolism. Rats were treated with TMZ for 4 weeks, and the fatty acid compositions were determined. Treatment with TMZ induced a significant decrease in phospholipid linoleic acid, balanced by a small increase in oleic and stearic acids. These changes were not correlated to alterations in plasma fatty acid composition. Cultured ventricular myocytes were treated with TMZ, 16 and 1 before experimentation. The time-dependent incorporation of radio labelled precursors of membrane phospholipids (3-inositol, 14C-ethanolamine, 14C-choline, 14C-arachidonic acid, 10 mumol/L) was investigated. The cells were harvested 30, 60, 105 or 150 min after precursor addition. In TMZ-cells, arachidonic acid (AA) incorporation was increased in the phospholipids, but not in other lipid fractions. This increase elicited a net increase in the total AA uptake. The incorporation of 3-inositol in the phospholipids was strongly stimulated by TMZ, although the uptake of inositol was not altered. The difference was significant within 30 min, and after 150 min the phospholipid labelling in TMZ cells was higher by 70%. A similar result was obtained with ethanolamine as precursor, which turnover increased by 50% in TMZ-treated cells. Conversely, the incorporation of choline was not significantly affected by the presence of TMZ. In conclusion TMZ appears to interfere with the metabolism of phospholipids in cardiac myocytes in a manner which could indicate an increase of membrane phospholipid turnover.

Animals↗

PubMed2000

Effect of L-arginine-nitric oxide system on the metabolism of essential fatty acids in chemical-induced diabetes mellitus.

Several studies have shown that the activities of delta-6-desaturase and delta-5-desaturase are depressed in experimental diabetes and in humans with insulin- and non-insulin-dependent diabetes mellitus (type I and type II diabetes mellitus respectively). Furthermore, treatment with insulin is known to correct the defects in desaturases in rats and humans with diabetes, especially in type I. In a recent study, we demonstrated that L-arginine and nitric oxide can prevent alloxan-induced beta cell damage, and the severity of diabetes, and restore the antioxidant status to near normal levels. But, no information is available as to the relationship between L-arginine-nitric oxide system and the metabolism of essential fatty acids in diabetes mellitus. In the present study, it was noted that the plasma levels of saturated fatty acids: stearic and palmitic were increased where as unsaturated fatty acids such as oleic, linoleic, gamma-linolenic and eicosapentaenoic acids (OA, LA, GLA and EPA respectively) were decreased in alloxan-induced diabetic rats. In the liver phospholipid (PL) fraction, GLA, DGLA (dihomo-GLA) and alpha-linolenic acid (ALA) were decreased in the alloxan-treated group; in the muscle PL fraction, LA, GLA and DGLA were low, whereas an increase in the saturated fatty acid content was noted. L-arginine (the precursor of nitric oxide) and sodium nitroprusside (a nitric oxide donor) treatment of alloxan-induced diabetic rats enhanced the levels of LA, GLA and DGLA. Further, nitric oxide synthase inhibitor, L-NMMA, prevented this beneficial action of L-arginine-nitric oxide system on essential fatty acid metabolism. The abnormalities in the essential fatty acid metabolism observed also reverted to normalcy following control of diabetes with insulin. These results indicate that nitric oxide can enhance the activities of delta-6- and delta-5 desaturases, which are depressed in diabetes, and suggests that there is a close interaction between L-arginine-nitric oxide system and the metabolism of essential fatty acids.

8,11,14-Eicosatrienoic Acid↗

PubMed1976

Artificial rearing of pigs. 5. The effect of different proportions of beef tallow or soya-bean oil and dried skim milk in the diet on growth, feed utilization, apparent digestibility and carcass compostion.

1. Diets containing different proportions of skim milk and fat, either beef tallow or soyabean oil, supplemented with fat-soluble vitamins were given to 2-d-old pigs. Each fat source was used in three diets containing approximately 280, 350 and 420 g fat, and 260, 235 and 210 g protein/kg dry matter respectively. 2. The diets were given as a milk containing 200 g solids/l during a 26 d experiment. The pigs were given the diet at hourly intervals according to a scale based on live weight. 3. Increasing the energy content of the diet, with the accompanying decrease in protein content, had no effect on live-weight gain or feed: gain ratio (g feed dry matter/g live-weight gain) (other than a slight reduction in live-weight gain when beef tallow was used), or on nitrogen retention. However, the fat content of the carcass of the 28-d-old pig was increased, and its protein and ash content were decreased. 4. The apparent digestibilities of the fatty acids ranged from 0-96 to 1-00. The faeces from pigs given the soya-bean-oil diets contained some eicosanoic, docosanoic and tetracosanoic acids, presumably of bacterial origin. In general, palmitic and stearic acids were slightly less well digested than oleic and linoleic acids.

Animals↗

PubMed1952

Growth requirements of dysgonic and eugonic strains of Mycobacterium tuberculosis var. bovis.

The nutritional requirements of dysgonic and eugonic bovine tubercle bacilli were investigated in liquid Tween-albumin medium. The following conclusions were reached:- Dysgonic bovine tubercle bacilli require for multiplication long chain fatty acids which can be supplied as oleic, palmitic, or stearic acid whereas eugonic bovine strains can grow in the absence of fatty acid and can utilize glucose as a sufficient source of carbon. In the presence of fatty acids, the growth of dysgonic strains is increased by the addition of small amounts of glucose or glycerol, whereas large amounts of glucose or glycerol decrease the total growth and inhibit or retard the growth of small inocula. In glucose-fatty acid media, the growth of dysgonic strains is further stimulated by the addition of sodium glutamate, succinate, malate, or acetate. Sodium pyruvate enables dysgonic strains to grow rapidly in liquid media containing glucose or glycerol even in the absence of fatty acid. The significance of these findings for the mechanism of the variation from "dysgonic" to "eugonic" is discussed. The use of oleic acid-albumin agar without glucose permits the rapid isolation of bovine tubercle bacilli from natural sources.

Animals↗

PubMed1996

Medium-chain triacylglycerols in formulas for preterm infants: effect on plasma lipids, circulating concentrations of medium-chain fatty acids, and essential fatty acids.

Limited information is available on the metabolic fate of medium-chain triacylglycerols (triglycerides) after intestinal absorption and on their influence on essential fatty acid metabolism. We studied in preterm infants the effect of two infant formulas, one with a high (HMCT) and one with a low (LMCT) medium-chain triacylglycerol content, on plasma fatty acids. The HMCT formula contained 46 mol% 8:0 + 10:0 and the LMCT formula (4.8 mol% 8:0 + 10:0) had approximately twice the amount of long-chain saturated and monounsaturated fatty acids as the HMCT. Both formulas had similar contents of linoleic and linolenic acids. Plasma lipids and fatty acids were determined at birth and on day 24 of life in 20 infants fed the LMCT (n = 12) or HMCT (n = 8) formula. Significant amounts of medium-chain fatty acids were found in the systemic circulation of the infants fed the HMCT formula, mainly in plasma fatty acids and triacylglycerols. Despite striking dietary differences, palmitic and stearic acids were not different between groups, indicating de novo synthesis of long-chain fatty acids with the HMCT formula. Plasma phospholipid docosahexaenoic acid was significantly lower in the HMCT group than in the LMCT infants (1.38 +/- 0.07 compared with 1.73 +/- 0.07 mol%, P = 0.002). Our data indicate that a high MCT intake in preterm infants increases lipogenesis, and dietary nonessential fatty acids interfere with the metabolism of docosahexaenoic acid.

Fatty Acids↗

PubMed2005

Susceptibility of Clostridium perfringens to C-C fatty acids.

AIMS: To determine susceptibility of Clostridium perfringens strains CCM 4435(T) and CNCTC 5459 to C(2)-C(18) fatty acids, and evaluate influence of pH in cultures grown on glucose. Straw particles were added to cultures to simulate the presence of solid phase of the digestive tract milieu. METHODS AND RESULTS: Antimicrobial activity of fatty acids was expressed as a concentration at which only 50% of the initial glucose was utilized. Lauric acid showed the highest antimicrobial activity, followed by myristic, capric, oleic and caprylic acid. Only strain CNCTC 5459 was susceptible to linoleic acid. Neither caproic acid and acids with a shorter carbon chain nor palmitic and stearic acid influenced substrate utilization. The antimicrobial activity of myristic, oleic and linoleic acid decreased when clostridia were grown in the presence of straw particles. In cultures of both strains treated with capric and lauric acid at pH 5.0-5.3, the number of viable cells was <10(2) ml(-1). Only lauric acid reduced number of viable cells of both strains below 10(2) ml(-1) at pH > 6. Transmission electron microscopy revealed separation of inner and outer membranes and cytoplasma disorganization in cells treated with lauric acid. CONCLUSIONS: Lauric acid had the highest activity towards C. perfringens among fatty acid tested. Its activity was not influenced by the presence of solid particles and did not cease at pH > 6. SIGNIFICANCE AND IMPACT OF THE STUDY: Lauric acid might be a means for control of clostridial infections in farm animals.

Clostridium Infections↗

PubMed1981

Utilization of arachidonic and linoleic acids by cultured human endothelial cells.

When cultured human umbilical vein endothelial cells are supplemented with linoleic acid, the arachidonic acid content of the cellular phospholipids is reduced approximately 35%. Most of the fatty acid compositional change occurs during the first 24 h. One factor responsible for this effect is the inability of the endothelial cells to convert appreciable amounts of linoleic to arachidonic acid, due to a fatty acid delta 6-desaturase deficiency. By contrast, these endothelial cultures contain delta 5- and delta 9-desaturase activity and are able to elongate long-chain polyunsaturated fatty acids. The other factor that contributes to the decrease in arachidonic acid is that high concentrations of linoleic acid reduce the incorporation of arachidonate into cellular phospholipids. Stearic acid, a long-chain saturate, does not produce any reduction, whereas eicosatrienoic acid is an even more effective inhibitor than linoleic acid. In spite of the fact that high concentrations of these polyunsaturates produced inhibition, the endothelial cells were found to efficiently incorporate exogenous arachidonic acid into cellular phospholipids and triglycerides. This may serve to compensate for the inability of these cells to synthesize arachidonic acid from linoleic acid. These findings suggest that the endothelium obtains arachidonic acid from an extracellular source, that this cannot be provided in the form of linoleic acid and, in fact, that high concentrations of linoleic acid actually may interfere with the ability of the endothelium to maintain an adequate supply of intracellular arachidonic acid.

Arachidonic Acid↗

PubMed1994

Appearance of ESR signals by the reaction of 3,5-dibromo-4-nitrosobenzenesulfonate (DBNBS) and non-radical biological components.

The reaction of 3,5-dibromo-4-nitrosobenzenesulfonate (DBNBS) with non-radical biological components produced spin adducts with ESR signals. The reactions of DBNBS with Trp, Gly-Trp, Trp-Gly, Pro, Cys and glutathione at pH 7.5 and room temperature for more than 1 hour gave the nitroxyl free radicals with ESR signals, whereas the reactions with other amino acids and bovine serum albumin did not. Among the amino acids and the peptides, Trp and Trp-containing peptides gave the most intense signals. The reactions of DBNBS with unsaturated fatty acids, i.e., linoleic acid and oleic acid, gave weak ESR signals, whereas the reaction with stearic acid did not. While DBNBS gave no ESR signals by the reactions with DNA, nucleosides and nucleobases, it caused strand breaking in supercoiled DNA. DBNBS also gave ESR signals by the reaction with human plasma similar to those from the reaction with Trp. It was suggested that the nitroxyl free radicals were produced by the addition of DBNBS to the amino acids and unsaturated fatty acids followed by oxidation in the presence of DBNBS. Hence, the use of DBNBS spin trap to detect free radicals in systems containing these biological components after long incubation may give misleading results.

Benzenesulfonates↗

PubMed1981

Digestion of fat in calves fed milk replacers prepared by homogenization of low-pressure dispersion.

High-fat (40% of dry matter) milk replacers were fed to calves from 3 to 14 days of age to determine the effect of fat dispersion method on abomasal retention of dietary fat and crude protein and on digestion of fat in upper parts of the gastrointestinal tract. Relative to homogenization, low pressure dispersion of fat into milk replacer resulted in a) much larger rennet clots in the abomasum, b) increased abomasal retention of dietary triglycerides and crude protein, and c) increased triglyceride hydrolysis in the abomasum, duodenum, and upper jejunum at 4 h after feeding. When high-fat diet was fed to postnatal calves, formation of large firm clots was beneficial for promoting a slower release of fat and protein into the duodenum, and digestion of fat was improved in the gastrointestinal tract. Pregastric esterase hydrolysis of dietary triglycerides (tallow, coconut oil) in the abomasum resulted in preferential release of capric, lauric, and myristic fatty acids and a proportionately low release of palmitic and stearic acids.

Abomasum↗

PubMed2004

Analysis of radiation-induced hydrocarbons and 2-alkylcyclobutanones from dried shrimps (Penaeus aztecus).

We investigated the usefulness of hydrocarbons and 2-alkylcyclobutanones as markers for irradiated, dried shrimps. A method was developed to detect the irradiation of dried shrimps (Penaeus aztecus) by identifying radiation-induced hydrocarbons and 2-alkylcyclobutanones extracted from dried shrimps, which were separated by Florisil column chromatography and identified by a method using gas chromatography/mass spectrometry. Radiation-induced hydrocarbons and 2-alkylcyclobutanones are formed from the fatty acids of the irradiated fats. The quantity of the hydrocarbons and 2-alkylcyclobutanones formed from some fatty acids is related to the composition of fatty acids in a sample. The concentrations of hydrocarbons and 2-alkylcyclobutanones increased with radiation dose. The major hydrocarbons in the irradiated, dried shrimps were 1-tetradecene and pentadecane from palmitic acid; small amounts of heptadecane and 1-hexadecene from stearic acid; and 8-heptadecene and 1,7-hexadecadiene from oleic acid. 2-(5'-Tetradecenyl)cyclobutanone, one of the 2-alkylcyclobutanones, was present at the highest concentration. The radiation-induced hydrocarbons and 2-alkylcyclobutanones were detected at radiation doses of 0.5 kGy and greater. These compounds were not detected in nonirradiated, dried shrimps.

Animals↗

PubMed1999

[Studies on chemical constituents of seeds of Desmos chinensis Lour].

OBJECTIVE: To investigate the chemical constituents of Desmos chinensis. METHOD: Various column chromatographic techniques were employed for the isolation and purification of constituents from the ethanol extract. The structures were elucidated by spectral analysis. RESULT: Eleven compounds were isolated and identified as lawinal(1), desmosal(2), desmethoxymatteucinol(3), unonal(4), isounonal(5), desmosflavone(6), allantoic acid(7), succinic acid(8), daucosterol(9), beta-sitosterol(10) and stearic acid(11). The structures of compounds 1 and 2 were reconfirmed by NOEDS technique. CONCLUSION: Compound 2 is a new natural product and 7, 8 and 9 were found from this plant for the first time.

Annonaceae↗

PubMed2005

[Studies on chemical constituents in fruit of Rubus chingii].

OBJECTIVE: To study the chemical constituents of the fruit of Rubus chingii. METHOD: The compounds were isolated and purified by recrystallization and chromatography with silica gel column and Sephadex LH-20 column. Their structures were identified by physicochemical properties and spectral analysis. RESULT: Eleven compounds were isolated as oleanic acid (I), ursolic acid (II), maslinic acid (III), 2alpha-hydroxyursolic acid (IV), arjunic acid (V), hexacosyl p-coumarate (VI), tiliroside (VII), stearic acid (VIII), lacceroic acid (IX), beta-sitosterol (X), daucosterol (XI). CONCLUSION: Compounds I, II, III, IV, V, VI, VIII, IX, XI were isolated from R. chingii for the first time.

Fruit↗

PubMed1991

Lipid contents of marine fish: Carcharhinus melanopterus (Black Shark) and Lutjanus johnii (Hira).

Total lipid composition of liver oil of two marine fish Carcharhinus melanopterus (Black Shark) and Lutjanus johnii (Hira) was determined. The fatty acid contents of total liver lipids were identified through gas chromatography-mass spectrometry. It was found that fatty acid methyl eaten mainly consist of myristic, pentadecylic, palmitic, stearic acids as saturated, and palmitoleic, oleic, elaidic, eicosapentaenoic, docosahexaenoic, and clupanodonic acids as unsaturated components. Appreciable quantities of polyunsaturated fatty acids (PUPA) and omega-3 fatty acids were detected.

Journal Article↗