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PubMed1997

Omega-3 fatty acid intake results in a relationship between the fatty acid composition of LDL cholesterol ester and LDL cholesterol content in humans.

The relationship between the fatty acid composition of the low density lipoprotein (LDL) cholesterol ester and LDL cholesterol content was assessed in 26 free-living, normal subjects. Dietary intakes of 14:0, 16:0, 18:0, 18:1, 18:2omega6, 18:3omega3, 20:4omega6, 20:5omega3, 22:6omega3 were calculated from seven-day food records kept by each subject at baseline and after three months of supplementation with olive, flaxseed or fish oil, respectively. A randomized cross-over design was used. The fatty acid content of specific foods was calculated. Fasting blood samples, taken at the beginning and end of each supplementation period, were analyzed for the fatty acid content present in individual lipoproteins. There was a significant correlation between 20:5omega3 and 22:6omega3 intake and the content of these fatty acids in the LDL cholesterol ester fraction. During the fish oil treatment period the 16:0 and 18:0 content of the LDL cholesterol ester was highly predictive of LDL cholesterol content. This relationship was not observed during the baseline or placebo (olive oil) supplement period.

Adult↗
PubMed1980

Fatty acid desaturation in lung: inhibition by unsaturated fatty acids.

The activity of the enzyme system involved in desaturation of palmitic and stearic acid has been examined in lungs of rats fed fat-free diets supplemented either with 4% safflower oil (controls) or 4% tripalmitin (essential fatty acid (EFA) deficient) both in vivo and in vitro in lung slices. Desaturation, as measured by appearance of 14C-labeled monounsaturated fatty acid in pulmonary total lipid and phospholipids, was significantly greater in vivo and in vitro in lung tissue from EFA-deficient rats. In vitro peincubation of lung slices for 1 to 4 hr with 1 mM oleic, linoleic, or linolenic acid reduced the extent of desaturation of [1-14C]-stearic acid significantly in both dietary groups, but the effect was greater in EFA-deficient tissues. The effect of linoleic acid was always greater than that of oleic acid. Preincubation with palmitic acid and 16,16-dimethyl PGE2 was without effect. Thus: 1) EFA deficiency has been shown to enhance desaturation of palmitic and stearic acid in lung; 2) in vitro addition of linoleic or linolenic acid inhibited desaturation significantly; and 3) oleic acid was inhibitory but to a lesser and more variable extent. Palmitic acid was not inhibitory.

16,16-Dimethylprostaglandin E2↗
PubMed2003

Trans unsaturated fatty acids are less oxidizable than cis unsaturated fatty acids and protect endogenous lipids from oxidation in lipoproteins and lipid bilayers.

Epidemiological data suggest that dietary trans unsaturated fatty acids increase the risk of heart disease; however, the underlying mechanisms are unclear. In this study, we investigated one possible mechanism, namely, their effect on LDL oxidation. Supplementation of LDL with 10% 16:1 trans-cholesteryl ester (CE) inhibited the oxidation compared to that with 16:1 cis-CE. Total replacement of core lipids with 18:2 trans,trans-CE decreased the rate of LDL oxidation by 19% compared to replacement with 18:2 cis,cis-CE. When the surface phosphoglycerides were replaced with either 16:0-18:2 cis,cis-phosphatidylcholine (PC) or 16:0-18:2 trans,trans-PC, the latter was found to inhibit the rate and increase the lag time of oxidation to a greater extent than the former. To confirm these findings, we studied the oxidation of PC liposomes by assessing the formation of conjugated dienes or the degradation of a fluorescently labeled PC. By both methods, the 16:0-18:2 trans,trans-PC exhibited greater resistance to oxidation than the 16:0-18:2 cis,cis-PC. Eliminating the fluidity differences did not completely eliminate the differences in oxidation rates, suggesting that the trans double bond is inherently resistant to oxidation. The composition of the conjugated hydroperoxy products formed after oxidation differed markedly for the two 18:2 isomers. Supplementation of 16:0-18:2 cis,cis-PC liposomes with 20 mol % di16:1 trans-PC retarded oxidation rates to a greater extent than supplementation with di16:1 cis-PC. These studies show that dietary trans unsaturated fatty acids decrease the rate of lipid peroxidation, an effect that may mitigate the atherogenic effect of these fatty acids.

Alkadienes↗
PubMed2000

Polyunsaturated fatty acid (fish or evening primrose oil) for schizophrenia.

BACKGROUND: Limited evidence gives support to an hypothesis suggesting that the symptoms of schizophrenia may result from altered neuronal membrane structure and metabolism. The latter are dependent on blood plasma levels of certain essential fatty acids (EFAs) and their metabolites. Several studies have shown those with schizophrenia often have low levels of the particular EFAs necessary for normal nerve cell membrane metabolism. OBJECTIVES: To review the effects of supplementing standard antipsychotic treatment with polyunsaturated fatty acids, whether essential (EFAs) or non-essential, for those with schizophrenia and, in recent updates to also evaluate the effects of EFA's as a sole antipsychotic treatment. To evaluate the relative efficacy of different types of fatty acid supplementation. SEARCH STRATEGY: Relevant randomised trials were identified by searching the following electronic databases: Biological Abstracts (1985-1998), CINAHL (1982-1998), Cochrane Library (Issue 4, 1999), Cochrane Schizophrenia Group's Register (February 2000), EMBASE (1980-1998), MEDLINE (1966-1998) and PsycLIT (1974-1998). In addition, reviewers searched references of included and excluded studies and contacted authors to identify further studies. SELECTION CRITERIA: All randomised clinical trials of polyunsaturated fatty acid supplementation to standard treatment or as primary intervention for schizophrenia (however defined) versus standard care. DATA COLLECTION AND ANALYSIS: Reviewers evaluated data independently and analysed on an intention-to-treat basis. They assumed that people who left the study early or were lost to follow-up had no improvement. Where possible and appropriate relative risk (RR) and their 95% confidence intervals (CI) were calculated. The number needed to treat (NNT) was estimated. For continuous data weighted mean differences (WMD) and their 95% confidence intervals were calculated. Data were inspected for heterogeneity and publication biases. MAIN RESULTS: Four relatively small trials (total n=204) showed low levels of loss to follow up and adverse effects for those taking essential fatty acids. Early results from a few trials suggest a positive effect of eicosapentaenoic acid (EPA) over placebo for scale-derived mental state outcomes. The data, however, is limited making these results difficult to analyse and interpret with confidence. A single small study (n=30) investigated the value of using EPA as sole treatment for people hospitalised for relapse. Results suggest that EPA may help one third of people avoid instigation of standard antipsychotic drugs for 12 weeks (RR 0.6, CI 0.4-0.91). There were no clear effects of primrose oil (omega-6) EFA supplementation. REVIEWER'S CONCLUSIONS: All data are preliminary, but results look encouraging for fish oil. EPA does not seem harmful, may be acceptable to people with schizophrenia and have moderately positive effect. A further trial is soon to be reported from the USA and more are underway or planned in the South Africa and Norway. Considering that EPA may be an acceptable intervention, large, long simple studies reporting clincially meaningful data should be anticipated.

Antipsychotic Agents↗
PubMed1992

An in vitro reversible interconversion of rat liver fatty acid binding protein having different isoelectric points by virtue of the fatty acid content.

Rat liver fatty acid binding protein (FABP) was purified to homogeneity by procedures including Sephadex G-100 and DEAE-cellulose column chromatographies. FABP was resolved into two major peaks, A and B, by the first DEAE-cellulose column chromatography. Each of these two fractions exhibited apparent homogeneity upon polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate with a molecular weight of 14,000 Da and amino acid analysis of these fractions has revealed that they are virtually identical or closely resemble each other. However, their fatty acid content was significantly different and heterogeneity was clearly demonstrated in the patterns of isoelectric focusing. In this communication, a single isoform (pI 5.0) from peak B FABP was further purified by successive DEAE-cellulose column chromatography and used as the final preparation. When the final FABP was partly freed of fatty acids by a mild delipidation technique using Lipidex 1,000, the pI shifted upward from 5.0 to 7.0. However, the pI of the delipidated FABP returned to its original pI of 5.0 after recombining fatty acids. These in vitro manipulations of bound fatty acid content made clear its possible cause of the microheterogeneity of FABP.

Amino Acids↗
PubMed2000

Effect of dietary protein quality and fatty acid composition on plasma lipoprotein concentrations and hepatic triglyceride fatty acid synthesis in obese cats undergoing rapid weight loss.

OBJECTIVE: To determine effects of dietary lipid and protein on plasma lipoprotein and free fatty acid concentrations and hepatic fatty acid synthesis during weight gain and rapid weight loss in cats. ANIMALS: 24 ovariohysterectomized cats. PROCEDURE: Cats were fed a high energy diet until they gained 30% of their ideal body weight and then randomly assigned to receive 1 of 4 weight reduction diets (6 cats/diet) at 25% of maintenance energy requirements. Diets contained a low or high quality protein source and a lipid source deficient or sufficient in long chain essential fatty acids. Plasma samples and liver biopsy specimens were obtained before and after weight gain and during and after weight loss for determination of free fatty acid, triglyceride, and lipoprotein concentrations. Synthesis of these substances was measured by use of isotope enrichment. RESULTS: Plasma total cholesterol concentration and concentration of lipoprotein fractions increased after weight gain, compared with baseline values. Weight loss resulted in a significant decrease in concentrations of all lipoprotein fractions except high density lipoprotein. High density lipoprotein concentration was significantly greater in cats fed diets containing an oil blend, compared with cats fed diets containing corn oil. Fatty acid synthesis after weight loss was below the detection limit of the measurement technique. CONCLUSIONS AND CLINICAL RELEVANCE: In cats undergoing rapid weight loss there is neither increased triglyceride synthesis nor decreased transport of very low density lipoproteins from the liver, suggesting that their involvement in the development of hepatic lipidosis may be minimal.

Animal Nutritional Physiological Phenomena↗
PubMed2002

Regiospecific distribution of fatty acids in triacylglycerols of Artemia franciscana nauplii enriched with fatty acid ethyl esters.

This paper reports the positional distribution of fatty acids in triacylglycerols (TAG) of Artemia franciscana nauplii enriched with each of palmitic (16:0), oleic (18:1n-9), linoleic (18:2n-6), linolenic (18:3n-3), eicosapentaenoic (20:5n-3), and docosahexaenoic (22:6n-3) acid ethyl esters. TAG extracted from the enriched and unenriched nauplii were subjected to regiospecific analysis to determine the fatty acid compositions of the sn-1(3) and sn-2 positions of TAG. In the unenriched nauplii, 16:0, 18:1n-9, and 18:2n-6 were preferentially located in the sn-1(3) position followed by the sn-2 position [i.e. sn-1(3)>sn-2], whereas 18:3n-3 was concentrated in the sn-2 position [i.e. sn-2>sn-1(3)]. Contents of 20:5n-3 and 22:6n-3 were low. After the nauplii were enriched with each of the ethyl esters for 18 h, fatty acid fed to the nauplii showed higher content in the sn-1(3) position than in the sn-2 position [i.e. sn-1(3)>sn-2]. Distribution pattern of 18:3n-3 changed from sn-2>sn-1(3) to sn-1(3)>sn-2 during the enrichment with 18:3n-3 ethyl ester. Increases in all of the fatty acids in TAG were attributed to that in the sn-1(3) position much more than that in the sn-2 position. Artemia nauplii appear to be characterized by preferential incorporation of exogenous fatty acids into the sn-1(3) position of TAG, even though endogenous fatty acids are esterified in the opposite position.

Animals↗
PubMed1988

Assessment of myocardial metabolism with iodine-123 heptadecanoic acid: effect of decreased fatty acid oxidation on deiodination.

Terminally radioiodinated fatty acid analogs are of potential use for the noninvasive delineation of regional alterations of fatty acid metabolism by gamma imaging. Since radioactivity from extracted iodine-123 heptadecanoic acid [( 123I]HDA) is released from the myocardium in form of free radioiodide (123I-) the present study was performed to determine whether deiodination of [123I]HDA is related to free fatty acid metabolism. Myocardial production of free radioiodide was measured in rat hearts in vitro and in vivo both under control conditions and after inhibition of fatty acid oxidation. In isolated rat hearts perfused at constant flow with a medium containing [123I]HDA, release of 123I- was markedly reduced during cardioplegia and pharmacologic inhibition of mitochondrial fatty acid transfer with POCA by 67% (p less than 0.005) and 72% (p less than 0.005), respectively. In fasted rats in vivo, 1 min after i.v. injection of [123I]HDA, 51 +/- 5% of myocardial radioactivity was recovered in the aqueous phase, containing free iodide, of myocardial lipid extracts. Aqueous activity was significantly decreased in fed (20 +/- 2%; p less than 0.002) and POCA pretreated (30 +/- 3.7%; p less than 0.05) animals exhibiting reduced oxidation of [14C]palmitate. Thus, deiodination of [123I]HDA was consistently reduced during inhibition of fatty acid oxidation in vitro and in vivo. The results apply to the interpretation of myocardial clearance curves of terminally radioiodinated fatty acid analogs.

Animals↗
PubMed1978

Influence of bile acids and free fatty acids on physicochemical properties of LP-X.

In this study it is demonstrated, that incubation of both, bile acids and free fatty acids with LP-X, the abnormal plasmalipoprotein found in patients suffering from cholestasis or LCAT-deficiency, results in striking alterations of the physico-chemical and immunological properties of LP-X: 1. The cathodic mobility in agar is changed into an anodic mairation of the material. 2. The unique appearance of LP-X on electronmicrographs is altered by the incubation revealing fingerprint like structures. 3. The albumin portion of LP-X becomes immunologically detectable. 4. Bile salts cause marked changes in the hydrated density of the material as determined by zonal ultracentrifugation. 5. In vitro incubation of LP-X with postheparin plasma causes a complete disappearance of LP-X as judged by its typical migration on agar electrophoresis. All these alterations can be prevented or reversed by the addition of albumin in appropriate concentrations. These findinga are important in the light of studies designed to investigate the catabolic action of plasma lipolytic enzymes on LP-X, as well as for follow up studies of LP-X concentrations during the course of disease.

Bile Acids and Salts↗
PubMed2001

The redfish species Sebastes viviparus, Sebastes marinus and Sebastes mentella have different composition of their tissue fatty acids.

The fatty acid profile in the tissue of heart, gill, skull- and otolith-oil of the three redfish species, Sebastes viviparus, S. marinus and S. mentella was determined by a chemometric method, consisting of methanolysis of samples of the tissues and of the oils and gas chromatography of the resulting fatty acid methyl esters. The analytical data were treated by multivariate statistics comprising principal component analysis (PCA) and soft independent modeling of class analogy (SIMCA). Although the differences in fatty acid composition among the two tissues and two oils were the dominating features of the data, the three species had significantly different fatty acid profiles within each tissue. Variation among the individuals was considerable. The fatty acid profiles appeared to be species specific. The mutual relationship between S. marinus and S. mentella is closer than the relationship between either of them and S. viviparus. A comparison with a corresponding investigation on the same three species from another location indicates that the observed differences do not seem to be affected by biotic or abiotic factors.

Animals↗
PubMedDate not supplied

The influence of fish oil diet and norepinephrine treatment on fatty acid composition of rat heart phospholipids and the positional fatty acid distribution in phosphatidylethanolamine.

The effect of chronic norepinephrine (NE) administration with increasing dosage from 1-4 mg/kg over a period of 2 weeks was studied on cardiac phospholipids and their fatty acid distribution in rats. Animals were fed a control diet or a 10% cod liver oil (CLO)-enriched diet. The relative distribution of various polyunsaturated fatty acids esterified to the 1- and 2-position of the phosphatidylethanolamine fraction was estimated. NE stress during control feeding significantly reduced the total phospholipid content in rat heart. No differences in the phospholipid class distribution were found. However, CLO feeding as well as chronic NE administration resulted in a decrease of omega 6 fatty acids, mainly C 18:2 omega 6 and C 20:4 omega 6, which was compensated with an increase in omega 3 fatty acids, mainly C 20:5 omega 3 and C 22:6 omega 3. The changes in fatty acid composition qualitatively agree with those reported by Gudbjarnason et al. (23), except that the mortality in our NE-treated control or CLO-fed groups was considerably lower. It can probably be attributed to a different mode of NE administration. On the other hand, at the end of the CLO feeding period in rats treated with NE or not, comparing with control fed rats without NE treatment, the incidence rate of ST segment elevation in electrocardiogram (ECG) recorded under light diethylether-induced anesthesia was higher. Independent of whether the fatty acid composition of myocardial phospholipids was dietary or pharmacologically manipulated, most of the polyunsaturated fatty acids were found at the 2-position of the phosphatidylethanolamine molecules. The polyunsaturated fatty acids account for 45-50% of the fatty acyl residues and preferentially occupy the 2-position, where they can exchange for each other.

Animals↗
PubMed1997

Stromal concentrations of coenzyme A and its esters are insufficient to account for rates of chloroplast fatty acid synthesis: evidence for substrate channelling within the chloroplast fatty acid synthase.

Concentrations of total CoAs in chloroplasts freshly isolated from spinach and peas were 10-20 microM, assuming a stromal volume of 66 microl per mg of chlorophyll. Acetyl-CoA and CoASH constituted at least 90% of the total CoA in freshly isolated chloroplasts. For a given chloroplast preparation, the concentration of endogenous acetyl-CoA was the same when extractions were performed using HClO4, trichloroacetic acid, propan-2-ol or chloroform/methanol, and the extracts analysed by quantitative HPLC after minimal processing. During fatty acid synthesis from acetate, concentrations of CoASH within spinach and pea chloroplasts varied from less than 0.1 to 5.0 microM. Malonyl-CoA concentrations were also very low (<0.1-3.0 microM) during fatty acid synthesis but could be calculated from radioactivity incorporated from [1-14C]acetate. Concentrations of CoASH in chloroplasts synthesizing fatty acids could be doubled in the presence of Triton X-100, suggesting that the detergent stimulates fatty acid synthesis by increasing the turnover rate of acyl-CoA. However, although taken up, exogenous CoASH (1 microM) did not stimulate fatty acid synthesis by permeabilized spinach chloroplasts. Calculated rates for acetyl-CoA synthetase, acetyl-CoA carboxylase and malonyl-CoA-acyl-carrier protein transacylase reactions at the concentrations of metabolites measured here are < 0.1-4% of the observed rates of fatty acid synthesis from acetate by isolated chloroplasts. The results suggest that CoA and its esters are probably confined within, and channelled through, the initial stages of a fatty acid synthase multienzyme complex.

Acetyl Coenzyme A↗
PubMed2002

Functional role of fatty acyl-coenzyme A synthetase in the transmembrane movement and activation of exogenous long-chain fatty acids. Amino acid residues within the ATP/AMP signature motif of Escherichia coli FadD are required for enzyme activity and fatty acid transport.

Fatty acyl-CoA synthetase (FACS, fatty acid:CoA ligase, AMP forming; EC ) plays a central role in intermediary metabolism by catalyzing the formation of fatty acyl-CoA. In Escherichia coli this enzyme, encoded by the fadD gene, is required for the coupled import and activation of exogenous long-chain fatty acids. The E. coli FACS (FadD) contains two sequence elements, which comprise the ATP/AMP signature motif ((213)YTGGTTGVAKGA(224) and (356)GYGLTE(361)) placing it in the superfamily of adenylate-forming enzymes. A series of site-directed mutations were generated in the fadD gene within the ATP/AMP signature motif site to evaluate the role of this conserved region to enzyme function and to fatty acid transport. This approach revealed two major classes of fadD mutants with depressed enzyme activity: 1) those with 25-45% wild type activity (fadD(G216A), fadD(T217A), fadD(G219A), and fadD(K222A)) and 2) those with 10% or less wild-type activity (fadD(Y213A), fadD(T214A), and fadD(E361A)). Using anti-FadD sera, Western blots demonstrated the different mutant forms of FadD that were present and had localization patterns equivalent to the wild type. The defect in the first class was attributed to a reduced catalytic efficiency although several mutant forms also had a reduced affinity for ATP. The mutations resulting in these biochemical phenotypes reduced or essentially eliminated the transport of exogenous long-chain fatty acids. These data support the hypothesis that the FACS FadD functions in the vectorial movement of exogenous fatty acids across the plasma membrane by acting as a metabolic trap, which results in the formation of acyl-CoA esters.

Adenosine Monophosphate↗
PubMed1994

Effect of administration of gamma-linolenic acid on the fatty acid composition of serum phospholipids and cholesteryl esters in patients with cystic fibrosis.

This study examined the effects of supplementing patients with cystic fibrosis daily for 4 weeks with 1,500 mg borage oil, containing 330 mg gamma-linolenic acid, on the fatty acid composition of serum phospholipids (PL) and cholesteryl esters (CE). Vital capacity and forced expiratory volume in 1 s were also measured before and after treatment. In serum PL the content of arachidonic acid (AA) increased and that of palmitic acid decreased significantly after borage oil administration. In serum CE dihomogamma-linolenic acid increased whereas docosahexaenoic acid decreased significantly. In this lipid class, AA and the sum of AA plus its precursor, dihomogamma-linolenic acid, increased significantly with the dose fed. A positive correlation was found between change in vital capacity and change in linoleic acid content of serum CE and AA content of serum PL.

Adolescent↗
PubMed2006

Dietary polyunsaturated fatty acids in gestation alter fetal cortical phospholipids, fatty acids and phosphatidylserine synthesis.

Docosahexaenoic acid (DHA; 22:6 n-3) is high in brain phosphatidylserine (PS) and phosphatidylethanolamine (PE), but low in phosphatidylcholine (PC). PS is synthesized from PE or PC by exchange of ethanolamine or choline for serine. PS can be decarboxylated to PE, and PC is synthesized from PE by phosphatidylethanolamine N-methyltransferase (PEMT). We characterized the perinatal changes in rat brain cortex phospholipids and metabolism and determined if maternal dietary n-3 fatty acid intake alters newborn brain cortex phospholipids, serine base exchange, PS decarboxylase or PEMT activities. PE became increasingly predominant, with an increase in the cortex PC/PE ratio from 2:1 at gestation day 19 to 1:1 at postnatal day 20. DHA increased and n-6 docosapentaenoic acid (DPA; 22:5 n-6) decreased in all phospholipids during development. [3H]serine incorporation into PS was higher in the fetal than neonatal brain cortex. Newborn rats of dams fed an n-3 fatty acid-deficient diet with 0.02% energy alpha-linolenic acid (ALA; 18:3 n-3) had approximately 50% lower DHA and higher DPA in cortex PE, PS and PC than newborns of rats fed a control diet with 1.5% energy ALA. [3H]serine incorporation into PS was significantly lower in the brain cortex of n-3 fatty acid-deficient than control newborns. n-3 Fatty acid deficiency had no effect on newborn brain PEMT or serine decarboxylase activities. These studies show that maternal dietary n-3 fatty acid deprivation impairs fetal brain DHA accretion and PS metabolism; altered PS metabolism may change release of lipid mediators and neurotransmitter precursors important in brain function.

Animals↗
PubMed2006

Impact of milking frequencies on the level of free fatty acids in milk, fat globule size, and fatty acid composition.

The aim of the present study was to study the effect of milking cows 4 times daily on free fatty acids (FFA) in the milk compared with milking twice daily. An experiment was performed during 2 wk in which half udders in 11 cows were milked 2 or 4 times daily. Milk yield was measured, and milk was analyzed for fat content, FFA, fatty acid composition, fat globule size, and activity of gamma-glutamyl transpeptidase. Concentration of FFA was greater (1.49 mEq/100 g of fat) in milk from half udders milked 4 times daily than in milk from the half udders milked twice daily (1.14 mEq/100 g of fat). Further, it was noted that milk from the half udder milked 4 times daily contained milk fat globules with larger average diameters. Increased milking frequency increased milk yield by 9% compared with the udder half milked twice daily, but fat content and fat yield were not affected. The results are of importance for further understanding the mechanisms behind the increased content of FFA that is frequently observed in automatic milking systems.

Animals↗