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PubMed1997

Plasma free fatty acids in mitochondrial fatty acid oxidation defects.

Plasma free fatty acid profiles from patients suffering from various mitochondrial beta-oxidation deficiencies were analyzed by gas chromatography-mass spectrometry. cis-4-Decenoic acid (10:1n-6) in medium-chain acyl-CoA dehydrogenase deficiency and cis-5-tetradecenoic acid (14:1n-9) in very-long-chain and 3-hydroxy-long chain acyl-CoA dehydrogenase deficiencies are characteristic of these diseases. In addition, patients with 3-hydroxy-long chain acyl-CoA dehydrogenase deficiency showed a specific increase of 3-hydroxy-long chain fatty acids. The study of plasma free fatty acids is an easy and useful methodology for the diagnostic approach of some mitochondrial beta-oxidation deficiencies, allowing us to establish a quick differentiation between medium- and long-chain defects.

Acyl-CoA Dehydrogenase↗

PubMed2000

Differences in the fatty acid composition of fatty acid ethyl esters in organs and their secretions.

BACKGROUND: Fatty acid ethyl esters (FAEE) are nonoxidative ethanol metabolites that have been shown to be long term markers of ethanol intake and have been implicated as mediators of ethanol-induced cell injury. Previous studies have indicated that the fatty acid composition of the FAEE found in the plasma of human subjects after ethanol ingestion is predominantly ethyl palmitate and ethyl oleate. This raised the possibility that there is some selectivity toward the fatty acid used for FAEE to be exported from the liver into the blood. METHODS: To address the hypothesis that the fatty acid composition of FAEE secreted from organs, such as the liver and pancreas, differs from the fatty acid composition of FAEE in the organs, this study was performed using rats that received ethanol by intra-arterial infusion. RESULTS: It was found that the fatty acids in FAEE differed significantly in plasma versus liver, bile versus liver, and pancreatic secretions versus pancreas. CONCLUSIONS: These results indicate that organs selectively export certain FAEE species.

Animals↗

PubMed1980

Transacylation as a chain-termination mechanism in fatty acid synthesis by mammalian fatty acid synthetase. Synthesis of butyrate and hexanoate by lactating cow mammary gland fatty acid synthetase.

1. Purified cow mammary gland fatty acid synthetase synthesized long-chain unesterified and short-chain esterified fatty acids. 2. A direct relationship was observed between the amount of short-chain products synthesized and the concentration of acetyl-CoA in the incubation medium. 3. The short-chain products were identified as butyryl-CoA and hexanoyl-CoA. 4. Inhibition of the terminating thioester hydrolase of the fatty acid synthetase complex with phenylmethanesulphonyl fluoride did not inhibit the synthesis of short-chain products. 5. It is suggested that the synthesis of short-chain fatty acids involves the reverse of the 'loading' reaction.

Animals↗

PubMedDate not supplied

Low molecular weight organic acids and fatty acids in root exudates of two Lupinus cultivars at flowering and fruiting stages.

Low molecular weight organic acids (LOAs) and fatty acids in root exudates of two lupin cultivars, Lupinus albus cv. Multolupa and L. luteus cv. Tremosilla, were determined at flowering and fruiting stages. LOAs were analysed by capillary electrophoresis. Acetic and citric acids were the most abundant, especially the latter in L. luteus at the flowering stage (5922.79 micrograms/g dry root). The significant decrease in acid content of both cultivars from flowering to fruiting stages was also striking. The highest levels of acetic acid were detected in L. luteus at fruiting stage (1542.03 micrograms/g dry root). The significant citrate production in L. luteus could be related to the low phosphorus concentration in the studied soils but not to proteoid roots, which were detected only in L. albus. The source of the LOAs detected in these exudates is also discussed, since they may be produced either by the plant or by the associated rhizobacteria. The profile of phospholipid fatty acids was determined by high-resolution GC. A high level of 18:2 omega 6 (a fatty-acid specific to fungi) was found in exudates of L. luteus (a mycorrhizal plant) in contrast to L. albus (a non-mycorrhizal plant).

Acids↗

PubMed1982

Influence of dietary essential fatty acid level on fatty acid composition in peripheral nerve and muscle.

Two groups of rats of different lines were divided into two lots. The four lots, whose dams received a fat-controlled diet, were fed with diets containing different levels of essential unsaturated fatty acids, namely linoleic (18:2 (n-6)) and linolenic (18:2 (n-3)) acid, in the oil. Nerve and muscle fatty acids were analyzed at adulthood. When the linolenic acid level was less than 0.6 p. 100 of the total fatty acids in the diets (peanut oil and sunflower oil), the level of long-chain polyunsaturated fatty acids (PUFA) of the (n-3) series decreased. This decrease was associated with an increase in the PUFA of the (n-6) series. Total PUFA ((n-3) + (n-6)) remained similar in the same group of rats, whatever the diet. On the contrary, when dietary linolenic acid reached 7.6 p. 100 (soya oil) or 8.5 p. 100 (rapeseed oil) of the total fatty acids, in the presence of a very high linoleic acid level, the PUFA of the (n-6) series decreased and that of the (n-3) series increased in nerve and especially in muscle. It appears that preferential PUFA biosynthesis from linolenic acid occurred when the ratio (n-6)/(n-3) was low enough in the dietary oil.

Animals↗

PubMed2005

[Changes in amino acid and fatty acid contents as well as activity of some related enzymes in apple fruit during aroma production].

Aroma volatiles from apple (Malus domestica Borkh. var. Starkrimson) fruit at different stages of maturity were collected by solid adsorbent-Tenax-GC and determined by thermodesorption and GC-MS. Production of propyl acetate, butyl acetate, ethyl 2-methyl-butanoate and total ester volatiles and changes in concentration of the precursors of aroma biosynthsis--free amino acids and fatty acids and activities of lipoxygenases (LOX) and alcohol acetyltransferase (AAT) in apple fruits during ripening were studied. The results showed that propyl acetate and total esters were very low when the endogenous ethylene formation of the fruit was very low. At the stage of the increase in ethylene production, the rate of formation of propyl acetate and total esters increased. Butyl acetate appeared at the beginning of ethylene rise and increased thereafter. Ethyl 2-methyl-butanoate was produced at the beginning of climacteric stage and then increased sharply (Figs.1). These facts suggest that the aroma production is closely related to ethylene production. Among the 14 free amino acids detected in fruit, isoleucine which is considered to be the biosynthetic precursor of some branched chain esters showed a great increase during fruit ripening while the others decreased or remained stable (Table 1). The accumulation of isoleucine suggested that isoleucine supply in fruit may not limit the biosynthesis of esters with branched chain alkyl groups. Concentrations of free fatty acids such as palmitic, linolenic, oleic, linoleic, stearic acids increased before the increase of aroma production, decreased with the increase of aroma production and showed an increase at postclimacteric stages (Fig.2). LOX activity increased at climacteric stages and declined rapidly thereafter. AAT activity increased sharply at the early stage of fruit maturity when the aroma was very low and remained at a stable high level during fruit ripening (Fig.3) indicating that the AAT activity is not the limiting factor for aroma formation in apple fruit.

Acetates↗

PubMed1982

The use of in vivo-in vitro labeling techniques to study phospholipid fatty acid turnover and fatty acid esterification into triglycerides in adipose tissue of aging mice.

We are interested in membrane phospholipid and triglyceride synthesis and turnover in aging cells. As a preliminary, short-term feasibility study we have used an established in vivo-in vitro technique to estimate the initial rates of [1-14C] palmitate (complexed to albumin) esterification to triglycerides and phospholipids in adipocytes and non-adipocytes in the epididymal fat pads of aging mice (8-92 weeks). We have expressed our data in terms of unit cell, unit triglyceride mass and unit (membrane) phospholipid mass. Fat pad and adipocyte size, cell surface area, and adipocyte volume changes were measured and found to follow the same relations as reported in the literature, with some exceptions in very old mice (retired breeders). Rates of fatty acid esterification to triglycerides were about 100 times faster than those to phospholipids in adipocytes. Aging caused a marked fall in the rates of triglyceride fatty acid formation from added palmitate; thus, the rate of fatty acid esterification to triglycerides fell from 0.75 to 0.13 nequiv. fatty acid per min per fat pad (youngest most active group, cf. oldest group). Esterification of fatty acids into phospholipids in adipocytes of the oldest mice was significantly lower than in those of the young and middle-aged groups. Contamination of adipocytes by non-adipocytes was observed in fat pads from old, but not from young, mice. The non-adipocytes accounted for about half of the phospholipid fatty acid esterification. The rate of phospholipid esterification was so slow in adipocytes (all ages) and so relatively fast in non-adipocytes that further studies of phospholipid fatty acid turnover in adipocytes using this system are not considered feasible, especially as a means for studying removal rates of autoxidized fatty acids from membrane phospholipids in vivo during aging.

Adipose Tissue↗

PubMed1983

Selective effects of isomeric cis and trans fatty acids on fatty acyl delta 9 and delta 6 desaturation by human skin fibroblasts.

Human skin fibroblasts incorporate and actively desaturate long-chain fatty acids. Growth of these cells in lipid-free medium can be used to enhance delta 9 and delta 6 desaturation of [14C]stearate and [14C]linoleate, respectively. Medium supplementation with cis fatty acids inhibits delta 9 desaturation; effectiveness as inhibitors is linoleate (9c,12c-18:2) greater than oleate (9c-18:1) greater than vaccenate (11c-18:1). Linoelaidate (9t,12t-18:2), trans-vaccenate (11t-18:1) and saturated fatty acids are without effect; elaidate (9t-18:1) appears stimulatory. By contrast, the trans fatty acids elaidate and linoelaidate are potent inhibitors of delta 6 desaturation; inhibition by trans-vaccenate is 50% of that of elaidate. Desaturation of [14C]linoleate is only slightly inhibited by oleate, cis-vaccenate, or (6c,9c,12c)-linolenate. The relative effectiveness of isomeric cis- and trans-octadecenoic acids as inhibitors of delta 9 and delta 6 desaturation in intact human cells is different from that found in microsomal studies. The cell culture system can thus be important in evaluating physiological effects of isomeric fatty acids on cellular metabolic processes.

Cells, Cultured↗

PubMedDate not supplied

Gas chromatographic analysis of infant formulas for total fatty acids, including trans fatty acids.

Twelve powdered and 13 liquid infant formulas were analyzed by using an extension of AOAC Official Method 996.01 for fat analysis in cereal products. Samples were hydrolyzed with 8 N HCl and extracted with ethyl and petroleum ethers. Fatty acid methyl esters were prepared by refluxing the mixed ether extracts with methanolic sodium hydroxide in the presence of 14% boron trifluoride in methanol. The extracts were analyzed by gas chromatography. In powdered formulas, saturated fatty acid (SFA) content (mean +/- SD; n = 12) was 41.05 +/- 3.94%, monounsaturated fatty acid (MUFA) content was 36.97 +/- 3.38%, polyunsaturated fatty acid (PUFA) content was 20.07 +/- 3.08%, and total trans fatty acid content was 1.30 +/- 1.27%. In liquid formulas, SFA content (mean +/- SD; n = 13) was 42.29 +/- 2.98%, MUFA content was 36.05 +/- 2.47%, PUFA content was 20.65 +/- 2.40%, and total trans fatty acid content was 0.88 +/- 0.54%. Total fat content in powdered formulas ranged from 4.4 to 5.5 g/100 kcal and linoleic acid content ranged from 868 to 1166 mg/100 kcal. In liquid formulas, total fat content ranged from 4.1 to 5.1 g/100 kcal and linoleic acid content ranged from 820 to 1100 mg/100 kcal. There were no significant differences between powdered and liquid infant formulas in concentrations of total fat, SFA, MUFA, PUFA, or trans fatty acids.

Algorithms↗

PubMed2002

Effects of dietary conjugated linoleic acid on fatty acid composition, lipid oxidation, color, and water-holding capacity of pork loin.

The effects of dietary conjugated linoleic acid (CLA) on fatty acid composition, lipid oxidation, and pork quality were investigated. Pigs (n = 20) were fed a diet containing 0, 1, 2.5, or 5% CLA for 4 wk and slaughtered at 105 kg. The longissimus thoracis et lumborum muscle was collected at 24 h postmortem. Pork loin chops (3 cm thick) were packaged aerobically and stored at 4 degrees C for 7 d. Samples were analyzed for ultimate pH, intramuscular fat content, fatty acid composition, thiobarbituric acid-reactive substances, color (L*, a*, b*), and water-holding capacity. Dietary CLA reduced the concentration of linoleic acid and increased CLA concentration in intramuscular fat of pork loin (P < 0.05). The concentration of CLA in muscle was increased with dietary CLA level and did not change during storage. Thiobarbituric acid-reactive substance value of control was higher than that of the CLA-fed groups (P < 0.05). Intramuscular fat content was increased by dietary CLA, and less purge loss was observed with samples from CLA-fed pigs (P < 0.05). Dietary CLA improved the color stability of pork loin during cold storage. After 7 d, lightness (L*) and yellowness (b*) of the 5% CLA-fed group were significantly lower than those of control (P < 0.05). The results indicated that the water-holding capacity of pork loin was increased with increased intramuscular fat content apparently caused by dietary CLA. Also, the data indicated that color stability of pork was improved with inhibition of lipid oxidation and changing of fatty acid composition by dietary CLA.

Animals↗

PubMed1982

Transacylation as a chain-termination mechanism in fatty acid synthesis by mammalian fatty acid synthetase. Synthesis of medium-chain-length (C8-C12) acyl-CoA esters by goat mammary-gland fatty acid synthetase.

1. Ruminant mammary-gland fatty acid synthetases can, in contrast with non-ruminant mammary enzymes, synthesize medium-chain fatty acids. 2. Medium-chain fatty acids are only synthesized in the presence of a fatty acid-removing system such as albumin, beta-lactoglobulin or methylated cyclodextrin. 3. The short- and medium-chain fatty acids synthesized were released as acyl-CoA esters from the fatty acid synthetase.

Acyl Coenzyme A↗

PubMed1980

Effects of prolonged starvation on plasma free fatty acid levels and fatty acid composition of myocardial total lipids in the rat.

Experiments were carried out on male rat fed ad libitum or starved for a period of 7 days. Plasma levels of free fatty acids (FFA) and the quantity and composition of fatty acids in total lipids of heart ventricular tissue in vivo were analyzed by gas liquid chromatography (GLC). In addition, FFA extraction ratios and uptake rates were determined in isolated perfused hearts using the classical Langendorff technique. After 7 days of starvation, distribution and concentrations obtained for total lipid fatty acids from heart ventricles of starved animals were substantially different from those of controls. In particular, 20:5 and 22:6 carbon polyunsaturated fatty acids were significantly elevated. Also, total plasma FFA level was elevated and FFA extraction ratios were increased as a result of prolonged starvation. Accumulation of 20- and 22-carbon polyunsaturated fatty acids observed in ventricles of starved rats may have resulted from increased availability and extraction of FFA.

Animals↗

PubMed2004

Regulation of fatty acid transport by fatty acid translocase/CD36.

Fatty acid (FA) translocase (FAT)/CD36 is a key protein involved in regulating the uptake of FA across the plasma membrane in heart and skeletal muscle. A null mutation of FAT/CD36 reduces FA uptake rates and metabolism, while its overexpression increases FA uptake rates and metabolism. FA uptake into the myocyte may be regulated (a) by altering the expression of FAT/CD36, thereby increasing the plasmalemmal content of this protein (i.e. streptozotocin-induced diabetes, chronic muscle stimulation), or (b) by relocating this protein to the plasma membrane, without altering its expression (i.e. obese Zucker rats). By repressing FAT/CD36 expression, and thereby lowering the plasmalemmal FAT/CD36 (i.e. leptin-treated animals), the rate of FA transport is reduced. Within minutes of beginning muscle contraction or being exposed to insulin FA transport is increased. This increase is a result of the contraction- and insulin-induced translocation of FAT/CD36 from an intracellular depot to the cell surface. Neither PPAR alpha nor PPAR gamma activation alter FAT/CD36 expression in muscle, despite the fact that PPAR alpha activation increases FAT/CD36 by 80% in liver. A novel observation is that FAT/CD36 also appears to be involved in mitochondrial FA oxidation, as this protein is located on the mitochondrial membrane and seems to be required to participate in moving FA across the mitochondrial membrane. Clearly, FAT/CD36 has an important role in FA homeostasis in skeletal muscle and the heart.

Biological Transport, Active↗

PubMed2002

Linoleic acid, other fatty acids, and the risk of stroke.

BACKGROUND AND PURPOSE: The role of serum fatty acids as a risk factor for stroke and stroke subtypes is largely unknown. METHODS: A prospective nested case-control study of Japanese 40 to 85 years of age was conducted through the use of frozen serum samples from 7450 participants in cardiovascular risk surveys collected from 1984 to 1989 for 1 community and 1989 to 1992 for the other 2 communities. By the end of 1998, we identified 197 incident strokes whose subtypes were confirmed by imaging studies. Three controls per case were selected by matching for sex, age, community, year of serum storage, and fasting status. RESULTS: Compared with controls, total (n=197), hemorrhagic (n=75), and ischemic (n=122) strokes had similar proportions of n3 polyunsaturated fatty acids, lower proportions of linoleic and arachidonic acids, and higher proportions of saturated and monosaturated acids, determined by gas chromatography. The multivariate odds ratios associated with a 1-SD increase in linoleic acid (5%) after adjustment for hypertension, diabetes, serum total cholesterol, and other cardiovascular risk factors were 0.72 [95% confidence interval (CI), 0.59 to 0.89] for total stroke, 0.66 (95% CI, 0.49 to 0.88) for ischemic stroke, 0.63 (95% CI, 0.46 to 0.88) for lacunar infarction, and 0.81 (95% CI, 0.59 to 1.12) for hemorrhagic stroke. The respective odds ratios for saturated fatty acids (4%) were 1.13 (95% CI, 1.05 to 1.65), 1.35 (95% CI, 1.01 to 1.79), 1.44 (95% CI, 1.03 to 2.01), and 1.21 (95% CI, 0.82 to 1.80). Further adjustment for other fatty acids attenuated these relations, but the relation between linoleic acid and risk of ischemic stroke remained statistically significant. CONCLUSIONS: A higher intake of linoleic acid may protect against ischemic stroke, possibly through potential mechanisms of decreased blood pressure, reduced platelet aggregation, and enhanced deformability of erythrocyte cells.

Adult↗

PubMed1980

Use of the conjugated polyene fatty acid, parinaric acid, in assaying fatty acids in serum or plasma.

We describe a method for rapidly assaying fatty acid concentrations in plasma or serum. This method is particularly appropriate for monitoring increased concentrations of fatty acids that may be present during intravenous lipid infusion, especially in neonates. Binding cisparinaric acid (9, 11, 13, 15-cis-trans-trans-cis-octadecatetraenoic acid) to albumin shifts the absorption spectrum of the acid. If fatty acids are present in serum, they will compete with parinaric acid for binding, changing the extent of this absorption shift. The measurement requires a spectrophotometer, 30 microL of serum or plasma, and knowledge of the sample's albumin concentration.

Bilirubin↗

PubMed1996

Kinetics of fatty acid interactions with fatty acid binding proteins from adipocyte, heart, and intestine.

Rate constants for the interaction of fatty acids (FA) with fatty acid binding proteins (FABP) from adipocyte (A-FABP), heart (H-FABP), and intestine (I-FABP) were determined by using stopped-flow fluorometry and ADIFAB, the fluorescent probe of free fatty acids (FFA), or a new FFA probe, ADIFAB2, constructed by derivatizing with acrylodan the Leu72 --> Ala mutant of I-FABP. ADIFAB2, because its binding affinities are about 10-fold greater than ADIFAB, was found to be more accurate for monitoring the kinetics of the higher affinity reactions. On- (kappa on) and off- (kappa off) rate constants were determined as a function of temperature. Our results reveal that in all cases the FA-FABP equilibrium is achieved within 2 s at 37 degrees C and within 20 s at 10 degrees C. Off-rate constants varied by about 10-fold among the different underivatized FABPs; kappa off values were smallest for H-FABP and largest for A-FABP, while kappa on values for these proteins generally varied by less than 2-fold. The results show that the previously reported larger affinities of I- and H-FABPs as compared to A-FABP are primarily a reflection of larger kappa on values for I-FABP and smaller kappa off values for H-FABP. Eyring transition state theory was used to evaluate the activation thermodynamic parameters for both on- and off-reactions and the results show that in virtually all cases the rate-limiting steps are predominantly enthalpic. Activation free energies for binding to ADIFAB are generally composed of about 8 kcal/mol unfavorable enthalpy and about a 1 kcal/mol favorable entropic contribution. For the underivatized FABPs the activation free energies are all about 7 +/- 0.3 kcal/mol, suggesting that the transition state for entering or leaving the binding site involves a common protein structural change. We suggest that entering or leaving the FABP binding cavity involves similar mechanisms for all 3 FABPs and may involve amino acid residues located within the portal regions of these proteins.

Adipocytes↗

PubMed1985

Effect of culture in vitro with eicosatetraenoic (20:4(n-6) ) and eicosapentaenoic (20:5(n-3) ) acids on fatty acid composition, prostaglandin synthesis and chemiluminescence of rat peritoneal macrophages.

Rat peritoneal macrophages were cultured in either eicosatetraenoic acid (20:4(n-6) ) or eicosapentaenoic acid (20:5(n-3) ) and the effects on phospholipid fatty acids, prostaglandin synthesizing capacity and the ability of the macrophages to show chemiluminescence were examined. Chemiluminescence is an activity resulting from the synthesis of reactive oxygen species. It has been reported that prostaglandins inhibit this activity. The fatty acid profile of the four major phospholipids reflected the fatty acid component of the medium. Macrophages cultured in 20:4(n-6) synthesized twice the prostaglandin produced by controls and those cultured in 20:5(n-3) synthesized 10% that of controls and 5% that of 20:4(n-6)-cultured cells. Macrophages cultured with 20:4(n-6) for 12 h showed half the chemiluminescence of those cultured with 20:5(n-3), while those cultured with 20:4(n-6) for 24 h showed 10% the chemiluminescence of 20:5(n-3)-cultured cells. Addition of the prostaglandin synthase inhibitor, indomethacin, had no effect on chemiluminescence.

5,8,11,14-Eicosatetraynoic Acid↗

PubMed1998

Effects of a newly developed fat emulsion containing eicosapentaenoic acid and docosahexaenoic acid on fatty acid profiles in rats.

A new fat emulsion of symmetrical triacylglycerols, containing only eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) was developed. The effects of this preparation on serum and liver fatty acid composition were investigated. Male Sprague-Dawley rats were fed a fat-free oral diet for 2 wk and were then divided into two groups. Seven rats were infused for 7 d with 1 mL of the new fat emulsion, which accounted for 1% of total caloric intake. The other 7 rats received saline. Both groups of rats received a fat-free diet during the infusion. EPA and DHA decreased to one third to one fifth of normal value after 2 wk on a fat-free diet. EPA and DHA of serum and liver remained at a low level in the control group throughout the study. But in the rats administered with the new fat emulsion, EPA and DHA increased rapidly and exceeded normal values in both serum and liver after 7 d of infusion. Decreased arachidonic acid with increased 20:3n-9 resulted in the rise of the triene/tetraene (T/T) ratio to greater than 0.4, indicating an n-6 essential fatty acid deficiency in the control rats. In the group administered the new fat emulsion, however, 20:3n-9 and total content of monounsaturated fatty acids decreased significantly, and the T/T ratio was less than than 0.4 in both serum and liver. In conclusion, the intravenous use of a newly developed fat emulsion containing EPA and DHA is useful in improving the EPA and DHA status of serum and liver without any harmful effects. Beneficial effects are expected in the modulation of inflammatory and stress response.

Animals↗