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PubMed1986

Free fatty acids and fatty acids of triacylglycerols in normal and hyperkeratotic human stratum corneum.

The content of the free fatty acids and the fatty acids of triacylglycerols has been measured in human plantar stratum corneum from normal and hyperkeratotic subjects with palmoplantar keratoderma. Fatty acids of triacylglycerols in normal tissues showed a characteristic pattern with a relative abundance of short-chain length and unsaturated fatty acids. Free fatty acid fraction was characterized by the predominance of saturated compounds. The relative amount of short-chain and monoene fatty acids in the hyperkeratotic stratum corneum was increased. These results seem to show a defect in the maturation of fatty acids in the living epidermis and present new evidence that the abnormality of lipid metabolism can influence the process of desquamation in stratum corneum.

Adult↗
PubMed1983

Separation and quantitation of free fatty acids and fatty acid methyl esters by reverse phase high pressure liquid chromatography.

Reverse phase high pressure liquid chromatography (HPLC) on octadecylsilyl columns separates mixtures of either free fatty acids or fatty acid methyl esters prepared from mammalian tissue phospholipids. Acetonitrile-water mixtures are used for the elution of esters. Aqueous phosphoric acid is substituted for water for the separation of the free acids. Unsaturated compounds are detected and quantitated by their absorption at 192 nm. Saturates are detected better at 205 nm. The order of elution of fatty acids in complex mixtures varies as a function of acetonitrile concentration. At any given concentration, some compounds overlap. However, by varying the solvent strength, any fatty acid of interest can be resolved including many geometrical and positional isomers. Methyl esters prefractionated according to unsaturation by argentation thin-layer chromatography (TLC) are rapidly and completely separated by elution with CH3CN alone. Argentation TLC-reverse phase HPLC can be used as an analytical as well as a preparative procedure. Octylsilyl columns are used for rapid resolution and improved detection of minor or low ultraviolet-absorbing components in the fractions. For example, monoenoic fatty acids with up to 32 carbons have been detected in bovine brain glycerophospholipids. Specific radioactivities of 3H- and 14C-labeled fatty acids and the distribution of radioactivity among acyl groups from complex lipids are measured. The method is not recommended for complete compositional analysis, but is useful for determinations of specific radioactivities during studies on turnover and metabolic conversions of labeled fatty acids.

Animals↗
PubMed1989

Trans fatty acids. 3. Fatty acid composition of the brain and other organs in the newborn piglet.

The effects of dietary trans fatty acids on tissue fatty acid composition were studied in newborn piglets delivered from sows fed partially hydrogenated fish oil (PHFO) (28% trans) or partially hydrogenated soybean oil (PHSBO) (36% trans) in comparison with lard (0% trans) from 3 wk of age and through gestation in Experiment 1, or fed PHFO or "fully" hydrogenated fish oil (HFO) (19% trans) in comparison with coconut oil (CF) (0% trans) with two levels, 1 and 2.7%, of dietary linoleic acid from conception through gestation in Experiment 2. The piglets were sampled immediately after delivery, without having access to mothers' milk. Incorporation of trans fatty acids into brain PE (phosphatidylethanolamine) were non-detectable or very low (less than 0.1%). The incorporation of 18:1 trans into heart-PE, liver mitochondria-PE, total plasma lipids and adipose tissue was low, and 20:1 trans was not detected. Dietary trans fatty acids had no consistent effects on the overall fatty acid composition of the different tissue lipids. It is concluded that trans fatty acids from PHFO, HFO and PHSBO have no significant effects on the fatty acid accretion in the fetal piglet.

Adipose Tissue↗
PubMed1989

Induction of peroxisomal beta-oxidation in 7800 C1 Morris hepatoma cells in steady state by fatty acids and fatty acid analogues.

(1) The activities of peroxisomal beta-oxidation and palmitoyl-CoA hydrolase in Morris hepatoma 7800 C1 cells were studied. The cells were grown until they reached steady state (constant DNA content per dish) and then were cultured in the presence of fatty acids or alkylthioacetic acids, i.e., S-substituted fatty acid analogues. (2) The fatty acid analogues increased the activity of the cyanide-insensitive palmitoyl-CoA oxidase several-fold. The effect was dose-dependent; 5 microM tetradecylthioacetic acid (TTA) was sufficient to give a significant induction. With 20 microM TTA, the increase in enzyme activity was discernable after 3 h and reached a maximum after 3 days. The inducing effect of the alkylthioacetic acids increased with the length of the hydrophobic alkyl end of the analogue. The inducing ability disappeared when the fatty acid analogue was omega-oxidized to the corresponding dicarboxylic acid. Oxidation of the sulfur atom resulted in inhibited cellular uptake and abolished enzyme induction. (3) At higher concentrations (0.5-1 mM), normal fatty acids also induced cyanide-insensitive palmitoyl-CoA oxidation. Myristic acid was the most potent inducer, whereas fatty acids with shorter as well as longer carbon chains were less efficient. The inducing effect increased with the number of double bounds in the fatty acid. (4) The normal fatty acids as well as the fatty acid analogues also induced palmitoyl-CoA hydrolase, but the relative changes were much less pronounced than with the palmitoyl-CoA oxidase.

Fatty Acids↗
PubMed2003

Effect of dietary protein quality and essential fatty acids on fatty acid composition in the liver and adipose tissue after rapid weight loss in overweight cats.

OBJECTIVE: To examine effects of dietary protein quality (casein [CA] vs corn gluten [CG]) and dietary lipids (corn oil [CO] vs oil blend [OB] rich in long-chain polyunsaturated fatty acids [LCPUFAs]) on fatty acid composition in liver and adipose tissue after weight loss in overweight cats. ANIMALS: 24 ovariohysterectomized adult cats. PROCEDURE: Cats were allowed ad libitum access to a high-quality diet until they weighed 30% more than their ideal body weight. Cats were then randomly assigned to 1 of 4 weight-reduction diets (6 cats/diet) and were fed 25% of maintenance energy requirements per day. Diets consisted of CG-CO, CA-CO, CG-OB, and CA-OB, respectively, and were fed until cats lost weight and returned to their original lean body mass. Liver biopsy specimens and samples of perirenal, subcutaneous, and abdominal fat were obtained and analyzed for fatty acid content. RESULTS: Following weight loss, fatty acid composition of the liver and adipose tissue was primarily affected by protein quality in that cats fed CA had significantly higher percentages of 20:4(n-6) and 22:6(n-3) fatty acids than those fed CG. Cats fed the CG-CO diet had the lowest concentrations of LCPUFAs, suggesting that dietary lipids and protein quality each influence fatty acid composition in tissues. CONCLUSIONS AND CLINICAL RELEVANCE: These data provide direct evidence that dietary protein quality alters fatty acid composition of tissues during weight loss in cats. The fatty acid patterns observed suggest that protein quality may alter fatty acid composition through modulation of desaturase activity.

Adipose Tissue↗
PubMed2004

Growth temperature affects accumulation of exogenous fatty acids and fatty acid composition in Schizosaccharomyces pombe.

The incorporation of exogenously supplied fatty acids, palmitic acid, palmitoleic acid, oleic acid and linoleic acid, was examined in the yeast Schizosaccharomyces pombe at two growth temperatures, 20 degrees C and 30 degrees C. Fatty acids supplied to S. pombe in the growth medium were found to be preferentially incorporated into the cells, becoming a dominant species. The relative increase in exogenous fatty acids in cells came at the expense of endogenous oleic acid as a proportion of total fatty acids. Lowering the temperature at which the yeast were grown resulted in decreased levels of incorporation of the fatty acids palmitic acid, palmitoleic acid and linoleic acid compared to cells supplemented at 30 degrees C. In addition, the relative amount of the endogenously produced unsaturated fatty acid oleic acid, while greatly reduced compared to unsupplemented cells, was increased in cells supplemented with fatty acids at 20 degrees C compared to supplemented cells at 30 degrees C. The differential production of oleic acid in S. pombe cells indicates that regulation of unsaturated fatty acid levels, possibly by control of the stearoyl-CoA desaturase, is an important control point in membrane composition in response to temperature and diet in this species.

Culture Media↗
PubMed1994

Interaction of rat liver microsomes containing saturated or unsaturated fatty acids with fatty acid binding protein: peroxidation effect.

In the studies described here rat liver microsomes containing labeled palmitic, stearic, oleic or linoleic acids were incubated with fatty acid binding protein (FABP) and the rate of removal of 14C-labeled fatty acids from the membrane by the soluble protein was measured using a model system. More unsaturated than saturated fatty acids were removed from native liver mircrosomes incubated with similar amounts of FABP. The in vitro peroxidation of microsomal membranes mediated by ascorbate-Fe++, modified its fatty acid composition with a considerable decrease of the peroxidizability index. These changes in the microsomes facilitated the removal of oleic and linoeic acids by FABP, but the removal of palmitic and stearic acids was not modified. This effect is proposed to result from a perturbation of membrane structure following peroxidation with release of free fatty acids from susceptible domains.

Animals↗
PubMed1996

Studies on acid oils and fatty acids for chickens. II. Effect of free fatty acid content and degree of saturation of free fatty acids and neutral fat on fatty acid digestibility.

1. Two experiments were designed to study the influence of free fatty acid content and degree of saturation of free fatty acids and neutral fat on digestibility of added fats and fatty acids. Sunflower oil and tallow were used as neutral fats, and palmitic, stearic, oleic and linoleic acids as free fatty acids. Fat inclusion was 80 g/kg and mixtures of each fat and each free fatty acid were prepared in the proportions 100:0, 70:30 and 40:60. 2. Experimental diets were evaluated for fat and fatty acid digestibilities with broiler chickens at 21 d of age. The metabolisable energy of fat was calculated from the product of digestibility and gross energy. Increasing concentrations of saturated free fatty acids decreased the ME of added fat, whereas unsaturated free fatty acids did not significantly affect the ME value of added fat. 3. Digestibilities of individual fatty acids were analysed by linear regression with rate of inclusion of free fatty acid in the fat blend: palmitic and stearic acids gave a negative slope, whereas oleic and linoleic acids gave a slope not statistically different from zero. Because slopes for saturated fatty acids did not differ between the sunflower oil and tallow treatments, synergism between unsaturated and saturated fatty acids was not detected.

Animal Feed↗
PubMed1992

trans fatty acids. 5. Fatty acid composition of lipids of the brain and other organs in suckling piglets.

The effects of dietary trans fatty acids on the fatty acid composition of the brain in comparison with other organs were studied in 3-wk-old suckling piglets. In Experiment (Expt.) 1 the piglets were delivered from sows fed partially hydrogenated fish oil (PHFO) (28% trans), partially hydrogenated soybean oil (PHSBO) (36% trans) or lard (0% trans). In Expt. 2 the piglets were delivered from sows fed PHFO, hydrogenated fish oil (HFO) (19% trans) or coconut fat (CF) (0% trans) with two levels of dietary linoleic acid (1 and 2.7%) according to factorial design. In both experiments the mother's milk was the piglets' only food. The level of incorporation of trans fatty acids in the organs was dependent on the levels in the diets and independent of fat source (i.e., PHSBO, PHFO or HFO). Incorporation of trans fatty acids into brain PE (phosphatidylethanolamine) was non-detectable in Expt. 1. In Expt. 2, small amounts (less than 0.5%) of 18:1 trans isomers were found in the brain, the level being slightly more on the lower level of dietary linoleic acid compared to the higher. In the other organs the percentage of 18:1 trans increased in the following order: heart PE, liver mitochondria PE, plasma lipids and subcutaneous adipose tissue. Small amounts of 20:1 trans were found in adipose tissue and plasma lipids. Other very long-chain fatty acids from PHFO or HFO (i.e., 20:1 cis and 22:1 cis + trans) were found in all organ lipids except for brain PE. Dietary trans fatty acids increased the percentage of 22:5n-6 in brain PE.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed2007

Identification of fatty acids and fatty acid amides in human meibomian gland secretions.

PURPOSE: The complex superficial lipid layer of the tear film functions to prevent evaporation and maintain tear stability. Although classes of lipids found in the tear film have been reported, individual lipid species are currently being studied with more sophisticated. METHODS: The purpose of this work was to show the identification of fatty acids and the fatty acid amides in human meibomian gland secretions by using electrospray mass spectrometry. methods. Human meibomian gland secretions (meibum) were analyzed by electrospray quadrupole time-of-flight mass spectrometry (positive- and negative-ion mode). Accurate mass determination and collision-induced dissociation of meibum, and lipid standards were used to identify lipid species. RESULTS: Mass analysis of meibum in an acidic chloroform-methanol solution in positive-ion mode revealed a mass peak of m/z 282.3, which was identified as the protonated molecule of oleamide [C(18)H(35)NO+H](+). The high-resolution mass analysis of the m/z 282.2788 peak (oleamide) demonstrated a mass accuracy of 3.2 parts per million (ppm). Collision-induced dissociation of this species from meibum, compared with an oleamide standard, confirmed its identification. Myristic, palmitic, stearic, and oleic free fatty acids were identified in a similar manner, as were the other fatty acid amides (myristamide, palmitamide, stearamide, and erucamide). CONCLUSIONS: The findings indicate that oleamide (cis-9-octadecenamide), an endogenous fatty acid primary amide, is a predominant component of meibum when examined by electrospray mass spectrometry. The novel finding of oleamide and other members of the fatty acid amide family in the tear film could lead to additional insights into the role of fatty acid amide activity in human biological systems and may indicate a new function for this lipid class of molecules in ocular surface signaling and/or in the maintenance of the complex tear film.

Bodily Secretions↗
PubMed1982

Propionyl-Coa induced synthesis of even-chain-length fatty acids by fatty acid synthetase from Brevibacterium ammoniagenes.

The product distribution of Brevibacterium ammoniagenes fatty acid synthetase has been investigated using propionyl-CoA instead of acetyl-CoA as the primer. The synthetase produces not only an odd-numbered fatty acid (heptadecanoic acid) but also even-numbered fatty acids (stearic and oleic acids) in the presence of propionyl-CoA. The amounts of heptadecanoic, stearic and oleic acids increased with increasing concentration of propionyl-CoA. However, the formation of heptadecenoic acid (C17:1) was not observed under any conditions tested. The failure of C17:1 synthesis suggested that the enzyme component catalyzing the beta, gamma-dehydration, which is responsible for the synthesis of unsaturated fatty acids, has a high degree of chain length specificity. Under standard assay conditions, stearic acid predominated and heptadecanoic and oleic acids were found in lesser amounts. Mass spectrometric analyses of fatty acids synthesized either from [2H]propionyl-CoA or in 2H2O revealed that propionyl-CoA is utilized as the priming substrate for the synthesis of heptadecanoic acid and that an acetyl residues, which is formed by the decarboxylation of malonyl-CoA, served as the priming substrate for the syntheses of stearic and oleic acids. No evidence was obtained for the direct decarboxylation of malonyl-CoA to acetyl-CoA in this reaction. It is concluded that the decarboxylation of the malonyl moiety bound to the synthetase occurs efficiently only in the course of fatty acid synthesis. A hypothetical scheme is presented to explain the propionyl-CoA-dependent decarboxylation of the malonyl moiety.

Acetyl Coenzyme A↗
PubMed1988

Trans fatty acids. 2. Fatty acid composition of the brain and other organs in the mature female pig.

Female pigs were fed from three wk of age and up to two years a diet containing partially hydrogenated fish oil (PHFO, 28% trans monoenoic fatty acids), partially hydrogenated soybean oils (PHSBO, 36% trans fatty acids) or lard. No consistent differences were found between PHFO and PHSBO with regard to incorporation of trans fatty acids in organ lipids, but trans incorporations were highly organ-specific. No trans fatty acids were detected in brain phosphatidylethanolamine (PE). The incorporation of monoenoic trans isomers, as a percentage of total cis + trans, in other organs was highest in subcutaneous adipose tissue and liver mitochondria PE, followed by blood lipids with the lowest level in heart PE. The percentage of trans isomers compared with that of dietary lipids was consistently lower for 20:1, compared with 18:1 in organs from PHFO-fed pigs. The only effect of dietary trans fatty acids on the fatty acid pattern of brain PE was an increased level of 22:5n-6. Heart PE and total serum lipids of pigs fed the hydrogenated fats contained higher levels of 18:2n-6, and these lipids of the PHFO-fed group also contained slightly elevated amounts of 20:3n-6, 18:3n-3 and 20:5n-3. Liver mitochondria PE of the PHFO group also contained higher levels of 20:3n-6 and 22:5n-6. Dietary trans fatty acids caused a consistent decrease of saturated fatty acids compensated by increased levels of monoenes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1981

Steric course of deuterium incorporation from [2-2H2]malonyl-CoA into fatty acids by fatty acid synthetases.

The steric course of the enoyl reduction catalyzed by fatty acid synthetase was investigated with the enzymes from bakers' yeast, rat liver and Brevibacterium ammoniagenes. The non-enzymic hydrogen-deuterium exchange of the methylene group of malonyl-CoA was studied by NMR spectroscopy. The half-life period of the methylene protons was 4.8 min at 37 degrees C and 12.2 min at 23 degrees C at p2H 7.5. Deuterium-labeled fatty acids were synthesized by incubating the synthetases with [2-2H2]malonyl-CoA for 8 min. The deuterium-labeled fatty acids thus produced were extracted and subjected to the action of acyl-CoA oxidase, which had been previously shown to catalyze the anti elimination of the pro-2R and pro-3R hydrogens of acyl-CoA. The resulting products, 2,3-dehydroacyl-CoAs, were methylated and converted to 3-chlorofatty acid methyl esters by addition of hydrogen chloride. The deuterium contents of saturated fatty acids and 3-chlorofatty acids were analyzed by gas chromatography-mass spectrometry. The oleic acid produced by the enzyme from B. ammoniagenes was oxidized to nonanoic acid and azelaic acid. The resulting nonanoic acid was also subjected to the action of acyl-CoA oxidase. The deuterium contents of nonanoic acid and trans-2-nonenoic acid were analyzed. The results suggested that fatty acid synthetase from yeast and rat liver incorporated hydrogen from water via a 2-Si attack and the enzyme from B. ammoniagenes incorporated hydrogen via a 2-Re attack during enoyl reduction. The partial racemization of the C-2 position was observed and the magnitude of this racemization was correlated with the deuterium content of synthesized fatty acids. This phenomenon may be attributed to the non-stereospecific hydrogen exchange of the C-2 position of the elongating acyl residue catalyzed by fatty acid synthetases.

Acyl Coenzyme A↗
PubMed1991

Dietary (n-3) fatty acids alter fatty acid composition and prostaglandin synthesis in rat testis.

The objective of this study was to determine the efficacy of linolenic acid [18:3(n-3)], compared with the long-chain (n-3) fatty acids in fish oil, in suppressing arachidonic acid [20:4(n-6)] metabolism in rat testis. Six groups of rats were fed three levels of 18:3(n-3) or fish oil, and the fatty acid composition of testis parenchyma lipids and prostaglandin (PG) I2 synthesis by tunica were determined after 12 wk. Levels of docosapentaenoic acid [22:5(n-6)], the major 22-carbon fatty acid in rat testis lipids, were significantly depressed compared with the control by both linolenic acid and fish oil; however, testis weights were not affected significantly. Arachidonic acid levels also were depressed significantly in testis lipids by dietary (n-3) fatty acids, but the decreases were not as pronounced as those observed in other tissues. The synthesis of PGI2 was significantly reduced compared with the control by (n-3) fatty acid feeding, but there were no differences among the experimental groups. Both 18:3(n-3) and the longer-chain (n-3) fatty acids from fish oil reduce levels of 20:4(n-6) and 22:5(n-6) in testis lipids and the capacity of the tunica to synthesize PGI2, but these fatty acids seem to cause no defect in testicular development as indicated by weight.

6-Ketoprostaglandin F1 alpha↗
PubMed2002

Effects of feeding pigs increasing levels of C 18:1 trans fatty acids on fatty acid composition of backfat and intramuscular fat as well as backfat firmness.

Forty Large White pigs were fed from 30 kg to 103 kg body mass on diets supplemented with 6% of pure high-oleic sunflower oil (HO) or HO plus increasing amounts of partially hydrogenated rape seed oil (HR; 1.85%, 3.70%, 5.55%), containing high levels of delta 6 to delta 11 C 18:1 trans fatty acid isomers. Increasing dietary C 18: trans fatty acids resulted in a linear increase in C 18:1 trans fatty acids and conjugated linoleic acid (cis-9, trans-11 CLA) in backfat (BF) as well as in neutral lipids (NL) and phospholipids (PL) of M. long. dorsi. Thus, the rate of bioconversion of trans vaccenic acid (TVA) into CLA and incorporation of C 18:1 trans and CLA into pig adipose tissue was not limited up to 25 g total C 18:1 trans fatty acids including 3.3 g of TVA per kg feed. BF was higher in C 18:1 trans fatty acids and CLA than M. long. dorsi NL and PL. In BF and NL the sum of saturated fatty acids (SFA) increased with increasing dietary amounts of HR, while in PL SFA were reduced. Thus, according to their physical properties, C 18:1 trans fatty acids partly replaced SFA in PL. Firmness of backfat was also significantly increased (P < 0.05) with increasing amounts of HR in feed.

Adipose Tissue↗
PubMed1986

Permeability behavior of liposomes prepared from fatty acids and fatty acid methyl esters.

The permeability properties of liposomes prepared at pH 8.7 from a fatty acid and either methyl oleate or methyl elaidate, with or without cholesterol, were investigated. The fatty acids used were oleic acid, elaidic acid, and the selenium-containing fatty acids 9-selenaheptadecanoic acid and 13-selenaheneicosanoic acid. The liposomes trapped sucrose and carboxyfluorescein. Their volume change resulting from osmotic shock was directly proportional to the change in absorbance (light scattering). Liposomes prepared from oleic acid and either methyl oleate or methyl elaidate underwent osmotic swelling much more slowly than liposomes prepared from elaidic acid and either methyl oleate or methyl elaidate. Incorporation of cholesterol decreased the initial rate of erythritol permeation, especially in liposomes containing methyl oleate. The swelling rates of liposomes prepared with the selenium-containing fatty acids indicated that incorporation of methyl elaidate gave more tightly packed bilayers than did incorporation of methyl oleate. The effect of cholesterol on the initial rate of erythritol influx was greater in oleic acid and elaidic acid liposomes than in selenium-containing fatty acid liposomes, indicating that the large bulk of the selenium heteroatom suppresses the ability of cholesterol to interact with the hydrocarbon chain.

Cholesterol↗
PubMed1985

Cholesterol, saturated fatty acids, polyunsaturated fatty acids, sodium, and potassium intakes of the United States population.

The USDA's 1977-1978 Nationwide Food Consumption Survey was utilized to assess dietary intake levels of cholesterol, fatty acids, sodium, and potassium by several age/sex groups of the U.S. population. Results indicated that mean cholesterol intakes for all male age groups of 12 yr and older exceeded 300 mg/day while the mean intakes of females and children were less than 300 mg/day. However, approximately 30% of each age group of adult females exceeded 300 mg cholesterol per day and only about one-third of the adult males had average intakes of less than 300 mg/day. Between 39% and 44% of total kilocalories were obtained from fat consumption with saturated fatty acids contributing 13-15%, polyunsaturated fatty acids contributing 5-6% and oleic acid contributing 12-14% of total kilocaloric intake. We found that 90% of children ages 6-11 yr and adult females had saturated fatty acids intakes of less than 40 gm/day; 90% of all men had intakes of less than 55 gm/day. At least 90% of all age/sex groups averaged intakes of polyunsaturated fatty acids of less than 26 gm/day. Average daily sodium intakes for each age/sex group (excluding table salt) were within the limits considered safe and adequate. However, approximately 4% of each age group of adult females and about 25% of each of the three younger adult male groups had average sodium intakes of 4000 mg/day or more. Average daily potassium intakes were somewhat low, ranging from 1584 mg/day for children ages 0-5 yr to 2735 mg/day for males ages 51-64 yr.

Adult↗