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At least 1,225 records · Page 68Linked to original sources
PubMed2003

Red blood cell fatty acid ethyl esters: a significant component of fatty acid ethyl esters in the blood.

Although alcohol abuse is known to cause an array of ethanol-induced red blood cell (RBC) abnormalities, the underlying molecular mechanisms remain poorly understood. Fatty acid ethyl esters (FAEEs) are toxic, nonoxidative ethanol metabolites that have been found in blood, plasma, and tissues. Because FAEEs have been shown to be incorporated into phospholipid bilayers, we conducted a controlled ethanol intake study to test the hypothesis that FAEEs accumulate and persist within RBCs following ethanol ingestion. We demonstrated that RBC FAEEs account for approximately 5% to 20% of total whole-blood FAEEs, and that the fatty acid composition of FAEEs in RBCs and plasma are different and vary differently over time. These data indicate that a significant percentage of FAEEs in the blood is associated with RBCs and that the metabolism of RBC FAEEs and that of plasma FAEEs (bound to albumin or lipoproteins) are largely independent.

Adult↗
PubMed1974

The enzymic and non-enzymic degradation of colneleic acid, an unsaturated fatty acid ether intermediate in the lipoxygenase pathway of linoleic acid oxidation in potato (Solanum tuberosum) tubers.

Colneleic acid is an unsaturated ether fatty acid derived from linoleic acid via a lipoxygenase-mediated enzyme pathway. It is degraded (a) by an enzyme in potato tubers which is heat-labile and non-dialysable and (b) by a model system containing catalytic amounts of Fe(2+) ions. Both enzyme- and Fe(2+)-catalysed systems have similar properties with respect to pH optima (pH5.0-5.5), oxygen requirement (0.6-0.7 mol of O(2) consumed/mol of ether degraded), inhibitors and reaction products. An unstable product breaks down to C(8) and C(9) carbonyl fragments. Both systems are inhibited by low concentrations of antioxidants (e.g. 5mum-butylated hydroxytoluene) and some chelating agents (e.g. 5mum-diethyldithio-carbamate). The model system is strongly inhibited by metal ions, particularly Cu(2+) and Fe(3+), at 20mum. Hydrogen peroxide and haemoproteins do not substitute for the enzyme or Fe(2+) ions but the non-haem iron protein, ferredoxin, does catalyse the degradation.

Antimetabolites↗
PubMed2004

Physicochemical properties of lipids: new strategies to manage fatty acid bioavailability.

Fatty acid bioavailability can be managed through the physicochemical properties of lipid such as lipid-droplet size, lipid-droplet ultrastructure (lipids organization between core and surface), structure of triglycerides and of phospholipids. The lipid-droplet size exhibits a major effect on lipase activity during lipid digestion. The lipid-droplet ultrastructure is a dynamic factor controling lipase interaction at the lipid interface via the surface phospholipid layer, and also lipase activity via the proportion of triglyceride molecules able to locate at the surface. Triglyceride structure affects in a strong manner digestion, absorption and fatty acid metabolism. Finally, optimal fatty acid transport to specific tissues is dependent on the vehicle molecule (triglyceride or ethyl ester or phospholipid). All these aspects provide convincing support for the possibility of using biotechnologically remodeled lipids with specific physicochemical properties for health benefits.

Animals↗
PubMed1998

Generalized peroxisomal disorder in male twins: fatty acid composition of serum lipids and response to n-3 fatty acids.

Male, identical twins presented with hypotonia, hypoglycaemia, dysmorphic facies, feeding problems, discoloured stools, hepatomegaly, and nephrolithiasis. Elevated blood levels of very long-chain fatty acids and bile acids suggested a peroxisomal disorder. Plasmalogen biosynthesis in cultured fibroblasts was reduced. Morphologically distinct peroxisomes were undetectable in liver. Twin 1 suffered from nephrocalcinosis and severe infection, and died at 18 months of age. Twin 2 was blind and physically severely retarded with epilepsy, but survived up to the age of 5 years. Studies of the fatty acid composition of serum lipids showed barely detectable values of eicosapentaenoic (EPA) and docosahexaenoic acid (DHA). During long-term treatment with these n-3 fatty acids, started at age 10 months, the fatty acid profile of the serum lipids was improved or normalized. Since n-3 fatty acids are essential elements in normal development, notably of the nervous system, we suggest that treatment with EPA and DHA should be started as early as possible in general peroxisomal disorders.

Diseases in Twins↗
PubMed2006

Polyunsaturated fatty acids and conjugated linoleic acid isomers in breast milk are associated with plasma non-esterified and erythrocyte membrane fatty acid composition in lactating women.

Maternal adipose tissue is a major contributor to breast milk long-chain fatty acids, probably through the pool of plasma NEFA. The fatty acid composition of the erythrocyte membrane (EM) is a biochemical index of the intake of fatty acids not synthesized endogenously and of PUFA and long-chain PUFA fatty acid status. The present study investigated the associations between breast milk fatty acid composition and the composition of plasma NEFA and of EM fatty acids with special reference to PUFA, long-chain PUFA and conjugated linoleic acid (CLA). The detailed fatty acid composition of mature breast milk was also reported. Thirty-three healthy, lactating Brazilian women donated milk samples; of these, twenty-four also donated blood samples in an observational cross-sectional study. Breast milk fatty acid composition presented several associations with NEFA and EM composition, which explained most (> or =50 %) of the variability of selected milk PUFA, long-chain PUFA and CLA. Milk CLA was associated with fatty acids that are markers of dairy fat intake in the diet, NEFA and EM. In general, breast milk n-3 fatty acids and CLA, but not n-6 fatty acids, were associated with EM composition, whereas both the n-6 and n-3 fatty acids and CLA in milk were associated with NEFA composition, possibly owing to its role as a direct source of fatty acids for breast milk. These findings emphasize the contribution of the NEFA pool derived from the adipose tissue to the long-chain fatty acid composition of breast milk.

Adult↗
PubMed1991

Fatty acid composition of subcellular particles from sheep platelets and topological distribution of phosphatidylethanolamine fatty acids in the plasma membrane.

The fatty acid composition of individual phospholipids in subcellular fractions of sheep platelets and the asymmetrical distribution of phosphatidylethanolamine (PE) fatty acyl chains across the plasma membrane were examined. The main fatty acids of total lipid extracts were oleic (18:1; 32-41%), linoleic (18:2, 10-17%), stearic (18:0; 13-15%), palmitic (16:0; 11-15%) and arachidonic (20:4; 8-12%) acids, with a saturated/unsaturated ratio of about 0.4. Each phospholipid class had a distinct fatty acid pattern. Sphingomyelin (SM) showed the highest degree of saturation (50%), with large proportions of behenic (22:0), 18:0 and 16:0 acids. The main fatty acid in PE, phosphatidylserine (PS) and phosphatidylcholine (PC) was 18:1n-9. Our findings suggest that fatty acids are asymmetrically distributed between the choline versus the non-choline phospholipids, and also between plasma membranes and intracellular membranes. The transbilayer distribution of PE fatty acids in plasma membranes from non-stimulated sheep platelets was investigated using trinitrobenzene-sulfonic acid (TNBS). A significant degree of asymmetry was found, which is a new observation in a non-polar cell. The PE molecules from the inner monolayer contained higher amounts of 18:2 and significantly less 18:1 and 20:5 than those found in the outer monolayer, although no major differences were detected in the transbilayer distribution of total unsaturated versus saturated PE acyl chains.

Animals↗
PubMed1977

Toxic effects of fatty acids on yeast cells: dependence of inhibitory effects on fatty acid concentration.

The yeasts Saccharomyces cerevisiae, Candida utilis, and Candida lipolytica were used to investigate the action of different concentrations of fatty acids (from acetic to myristic acid) on cell growth, division, uptake of inorganic phosphate, and substrate oxidation. The former two yeasts were found to undergo an inhibition of growth, cell division, and phosphate uptake at lower acid concentrations and to experience the inhibition of substrate oxidation at higher acid concentrations. The concentration dependence of the action of fatty acids can be classified into four categories: 1) subthreshold concentrations which do not inhibit growth and have either no effect on, or stimulate, oxygen consumption; 2) threshold concentrations which lower the rate of growth, cell division, and phosphate uptake but do not inhibit the oxidation of carbon substrate; 3) above-threshold concentrations which inhibit partially even substrate oxidation, and 4) microbicide concentrations. Candida lipolytica displays the same sensitivity toward the action of fatty acids as the above yeast species; however, the threshold concentrations are higher and can be quickly lowered owing to oxidation by the yeast. The concentrations of fatty acids found in the medium after cultivations of yeast with n-alkanes are of the same order as limiting concentrations; the formation of acids with twelve and less carbons in the molecule can thus be assumed to be one of the basic reasons for lowering of biomass yields during cultivations on these hydrocarbons.

Aerobiosis↗
PubMed2002

Retinal fatty acid binding protein reduce lipid peroxidation stimulated by long-chain fatty acid hydroperoxides on rod outer segments.

In the present study we have investigated the effect of partially purified retinal fatty acid binding protein (FABP) against nonenzymatic lipid peroxidation stimulated by hydroperoxides derived from fatty acids on rod outer segment (ROS) membranes. Linoleic acid hydroperoxide (LHP), arachidonic acid hydroperoxide (AHP) and docosahexaenoic acid hydroperoxide (DHP) were prepared from linoleic acid, arachidonic acid and docosahexaenoic acid, respectively, by means of lipoxidase. ROS membranes were peroxidized using an ascorbate-Fe(+2) experimental system. The effect on the peroxidation of ROS containing different amounts of lipid hydroperoxides (LOOH) was studied; ROS deprived of exogenously added LOOH was utilized as control. The degradative process was measured simultaneously by determining chemiluminescence and fatty acid composition of total lipids isolated from ROS. The addition of hydroperoxides to ROS produced a marked increase in light emission. This increase was hydroperoxide concentration-dependent. The highest value of activation was produced by DHP. The decrease percentage of the more polyunsaturated fatty acids (PUFAs) (20:4 n6 and 22:6 n3) was used to evaluate the fatty acid alterations observed during the process. We have compared the fatty acid composition of total lipids isolated from native ROS and peroxidized ROS that were incubated with and without hydroperoxides. The major difference in the fatty acid composition was found in the docosahexaenoic acid content, which decreased by 45.51+/-1.07% in the peroxidized group compared to native ROS; the decrease was even higher, 81.38+/-1.11%, when the lipid peroxidation was stimulated by DHP. Retinal FABP was partially purified from retinal cytosol. Afterwards, we measured its effect on the reaction of lipid peroxidation induced by LOOH. As a result, we observed a decrease of chemiluminescence (inhibition of lipid peroxidation) when adding increasing amounts (0.2 to 0.6 mg) of retinal FABP to ROS. The inhibitory effect reaches its highest value in the presence of DHP (41.81+/-10.18%). Under these conditions, bovine serum albumin (BSA) produces a smaller inhibitory effect (20.2+/-7.06%) than FABP.

Animals↗
PubMed1981

Distribution of arachidonic acid and other fatty acids in the lipids of guinea-pig uterus and plasma in relation to uterine prostaglandin synthesis.

Prostaglandin precursor fatty acids, predominantly arachidonic acid, were found in the different lipid classes of guinea-pig uterus and plasma on Days 7 and 15 of the oestrous cycle. Of the total arachidonic acid in the uterus, 93% was esterified to uterine phospholipids, of which 80% was bound to phosphatidylcholine and phosphatidylethanolamine. There was a significant decrease in the quantity of arachidonic acid bound to phosphatidylcholine between Days 7 and 15 of the oestrous cycle. Less than 0.1% of the uterine arachidonic acid was present in the unesterified form. It is suggested that phosphatidylcholine may form the source of phosphatidyl for uterine prostaglandin synthesis in the guinea-pig.

Animals↗
PubMed1989

Effects of dietary fatty acid composition on macronutrient selection and synaptosomal fatty acid composition in rats.

Our previous work showed that rats consuming 20% (wt/wt) lard diets selected more protein and less carbohydrate than did rats fed 20% (wt/wt) soybean oil diets. To determine if this effect is specific to saturated fat source and to measure changes in fatty acid composition of synaptosomal phospholipids, male Wistar rats were fed a 20% (wt/wt) soybean oil or tallow diet with 24% protein and 48% carbohydrate for 2 wk. Rats then self-selected from two diets with the same fat previously fed but different protein and carbohydrate composition (5% protein, 67% carbohydrate and 55% protein, 17% carbohydrate). Tallow-fed rats selected more protein and less carbohydrate than did soybean oil-fed rats. Dietary fat also affected fatty acid composition of synaptosomal phospholipids, phosphatidylcholine being most affected and phosphatidylinositol most resistant. Later studies determined if selection differences were due to taste. When rats self-selected without prior exposure to diets, tallow-fed rats selected more protein and less carbohydrate than did soybean oil-fed rats during the last 2 wk but not the first 2 wk. When rats selected from diets with identical protein and carbohydrate composition but different dietary fat, rats consumed slightly greater amounts of the tallow diet at each protein level. The relative intake of tallow and soybean oil diets, however, did not vary significantly with dietary protein treatment. These results confirm that rats fed saturated fat diets select more protein and less carbohydrate than do rats fed polyunsaturated fat diets and suggest this difference is not due to taste factors.

Analysis of Variance↗
PubMed1993

Long-chain alpha-hydroxy-(omega-1)-oxo fatty acids and alpha-hydroxy-1,omega-dioic fatty acids are cell wall constituents of Legionella (L. jordanis, L. maceachernii and L. micdadei).

Four long-chain fatty acids, 2-hydroxy-27-oxo-octacosanoic acid (n28:0(2-OH,27-oxo)), 2-hydroxy-29-oxo-triacontanoic acid (n30:0(2-OH,29-oxo)), 2-hydroxy-heptacosane-1,27-dioic acid (27:0(2-OH)-dioic) and 2-hydroxy-nonacosane-1,29-dioic acid (29:0(2-OH)-dioic) were identified by GLC-MS analysis in the phenol-chloroform-petroleum ether (PCP) extracts of Legionella jordanis, L. maceachernii and L. micdadei indicating that they are constituents of lipopolysaccharide. Moreover, five long-chain fatty acids (28:0(27-OH), 28:0(27-oxo), 30:0(29-oxo), 27:0-dioic and 29:0-dioic) previously identified in L. pneumophila (Moll, H. et al., FEMS Microbiol. Lett., 97 (1992), 1-6) were also found in these species. This is to our knowledge the first report on the existence of long chain 2-hydroxylated (omega-1)-oxo fatty acids and 2-hydroxylated 1,omega-dioic fatty acids.

Cell Wall↗
PubMed1994

Metabolism of dietary stearic acid relative to other fatty acids in human subjects.

This paper reviews results obtained by stable-isotope-tracer methods for stearic acid (18:0) and palmitic acid (16:0) metabolism and the influence of dietary linoleic acid on the metabolism of these saturated fatty acids in humans subjects. The results, based on stable-isotope-tracer data, show that absorption of 18:0 is not significantly different from 16:0; percent desaturation of 18:0 to 9-cis 18:1 (9.2%) is 2.4 times higher than for 16:0 to 9-cis 16:1 (3.9%) and 9-desaturation is not greatly influenced by the amount of linoleic acid in typical US diets. Additionally, compared with 16:0, 18:0 incorporation is 30-40% lower for plasma triglyceride and cholesterol ester and approximately 40% higher for phosphatidylcholine; beta-oxidation of saturated fatty acids was slower than for unsaturated fatty acids and increasing the intake of dietary linoleic acid decreased beta-oxidation of saturated fatty acids. These results indicate that metabolic differences between 18:0 and 16:0 only partially explain the difference in the cholesterolemic effect reported for these saturated fatty acids.

Absorption↗
PubMedDate not supplied

Action of long-chain fatty acids on protein kinase C activity: comparison of omega-6 and omega-3 fatty acids.

The results presented in this paper indicate that long chain free fatty acids have a dual modulatory effect on Protein Kinase C (PKC) activity purified from rat colon. Saturated (stearic) and monounsaturated (oleic) fatty acids are weak activators of PKC in the absence of phosphatidyl serine (PS) and diolein (DO), but have no significant effect on the PS/DO stimulated activity. Increasing the degree of unsaturation of the fatty acid, such as linolenic, arachidonic and eicosapentaenoic acids, also increases their stimulatory action toward unstimulated PKC, as well as their inhibition of PS/DO stimulated enzyme activity. Within this group of fatty acids there is no significant difference in the response of PKC toward omega-6 versus omega-3 type fatty acids. However, docosahexaenoic acid, a 22 carbon omega-3 polyunsaturated fatty acid found primarily in fish oil affected PKC differently from all other fatty acids studied. This compound was unable to stimulate dormant PKC activity, but was a highly potent inhibitor of PS/DO stimulated PKC. It is hypothesized that the inhibitory action of this omega-3 fatty acid may contribute to the protective role of fish oil consumption on colon tumorigenesis.

Animals↗
PubMed1978

The effect of dihomo-gamma-linolenic acid (20: 3,n-6) on the composition of phospholipid fatty acids in the liver of rats deficient in essential fatty acids.

1. Rats were fed on either a diet deficient in essential fatty acid (EFA) or one supplemented with dihomo-gamma-linolenic acid (20:3,n-6) at levels that represented 0.25, 0.5, 1.0 and 2.0% of the dietary energy. 2. Supplementation of the diet of EFA-deficient animals with 20:3,n-6 reversed most of the fatty acid changes induced in the liver phospholipid fraction. 3 The EFA potency of 20:3,n-6 was found to be similar to that of gamma-linolenic acid (18:3,n-6) which has been shown to be higher than that of linoleic acid (18:2,n-6).

8,11,14-Eicosatrienoic Acid↗
PubMed1997

The effects of dietary supplementation with docosahexaenoic acid on the phospholipid fatty acid composition of avian spermatozoa.

This study represents an attempt at the dietary manipulation of the fatty acid composition of chicken spermatozoa in order to enhance the levels of n-3 polyunsaturates at the expense of the n-6 fatty acids, which normally predominate in the lipids of avian semen. Male chickens were provided with either a control diet supplemented with maize oil or the test diet supplemented with fish oil (Tuna Orbital Oil) from 10 weeks of age. Semen samples were collected from the birds after 30 and 48 weeks of supplementation. The fish oil diet induced a significant but limited increase in the proportion of 22:6n-3 in the spermatozoan phospholipid in parallel with an equivalent decrease in the proportions of 20:4n-6 and 22:4n-6. However, since the maximal level of 22:6n-3 in the phospholipid that was achieved by fish oil feeding was less than 10% (wt/wt of fatty acids), these changes fell far short of representing a switch from the typical avian pattern to that more characteristic of the n-3 enriched mammalian semen. Analysis of the fatty acid compositions of the constituent classes of phospholipid in the spermatozoa indicated that, in both dietary states, the phosphatidylethanolamine fraction contained much greater proportions of n-6 and n-3 C20-22 polyunsaturates than the phosphatidylcholine fraction. The results indicate that the typical fatty acid profile of the spermatozoa of domesticated poultry, characterised by the predominance of C20-22 n-6 polyunsaturates, displays a considerable degree of resistance to manipulation by dietary means and does not adopt the "mammalian" type of profile following supplementation with n-3 fatty acids.

Animals↗