Phospholipid content and fatty acid composition of human heart

Phospholipid content and fatty acid composition of human heart were determined on 36 biopsy specimens collected during open heart surgery. The main phospholipid classes, phosphatidylcholine (PC), phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), and sphingomyelin (SPH) were separated by HPLC, quantified, and converted to fatty acid methyl esters which were chromatographed on capillary GLC columns. Sex and age (mainly 40–70) of patients had no significant influence on the relative distribution of phospholipid classes and only a slight effect on fatty acid composition. Incorporation oftrans 18∶1 in phospholipid classes was low.cis andtrans octadecenoic isomers seemed to be selectively incorporated, the Δ9 and Δ11cis ortrans isomers being predominant. Human and rat data were compared, and some species differences were noticed. In human PC, palmitic acid is higher and stearic acid much lower than in rat PC. Saturated dimethyl acetals (16∶0 and 18∶0) in PC and PE were greater for humans. Incorporation of 20∶4 n−6 in human PE is higher than in rat PE.     

Phospholipid and fatty acid composition of Bulgarian nut oils

The phospholipid and fatty acid composition of three Bulgarian nut oils were investigated. Phospholipids were separated by Folch′s method and two-directional thin-layer chromatography. Their content was determined spectrophotometrically. Phospholipids were present at levels of 0.8% in almond oil, 2.8% in hazelnut oil, and 0.9% in walnut oil. Phosphatidylcholine (18—50%), phosphatidylinositol (18—45%), and phosphatidylethanolamine (8—16%) were found to be the major components. Small amounts of phosphatidylserine, phosphatidic acids, phosphatidylglycerols, lysophosphatidylcholine, and lysophosphatidylethanolamine were also detected. The fatty acid composition of glyceride oils and of the four main phospholipids, namely phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and phosphatidic acids was identified by capillary gas chromatography of their methyl esters. The predominant fatty acid present in almond and hazelnut oils was linoleic (83.2% and 80.8%, respectively). Oleic acid (18.7%), linoleic acid (48.5%), and linolenic acid (15.8%) were the major components in walnut oil. Higher quantities of saturated fatty acids (27.8—81.2%) were found to be in the phospholipids than in the corresponding oils (9.5—16.7%).     

Phospholipid fatty acid composition and stereospecific distribution of soybeans with a wide range of fatty acid composition

Phospholipid (PL) fatty acid composition and stereospecific distribution of 25 genetically modified soybean lines with a wide range of compositions were determined by gas chromatography and phospholipase A₂ hydrolysis. Pl contained an average of 55.3% phosphatidylcholine, 26.3% phosphatidylethanolamine, and 18.4% phosphatidylinositol. PL class proportions were affected by changes in overall fatty acid composition. PL fatty acid composition changed with oil fatty acid modification, especially for palmitate, stearate, and linolenate. Stereospecific analysis showed that saturated fatty acids were primarily located at the sn-1 position of all PL, and changes of the saturates in PL were largely reflected on this position. Oleate was distributed relatively equally between the sn-1 and sn-2 positions. Linoleate was much more concentrated on sn-2 than on sn-1 position for all PL. Linolenate was distributed relatively equally at low concentration but preferred sn-2 position at high concentration.     

Phospholipid and fatty acid composition of frog (Rana esculenta) liver—a circannual study

Liver lipid composition of the frogRana esculenta was examined on a circannual basis. In particular, phospholipid and cholesterol content, relative phospholipid distribution, and fatty acid patterns have been studied. Seasonal acclimatization is associated with significant modifications of phospholipid content and of the relative proportion of phospholipid classes, while cholesterol level is unchanged throughout the year. In regard to the fatty acid composition of total phospholipids as well as of the four major phospholipid classes—phosphatidylcholine (PC); phosphatidylethanolamine (PE); sphingomyelin (SM); phosphatidylserine (PS)—it appears that the liver of “summer animals” is characterized by a higher unsaturation index due to a decrease of saturated fatty acids and to an increased content of n−3 and n−6 polyunsaturated fatty acids. The results suggest that relevant compositional changes occur mainly in spring and autumn: these changes could be interpreted as being the result of both a nutritionally- and thermally-induced seasonal adaptation directed toward the preservation of membrane-associated physiological activities that are linked to the transition from the active to the inactive state of the animal.     

Phospholipid fatty acid composition in type I and type II rat muscle

The fatty acid composition of the membrane phospholipids phosphatidylcholine (PC) and phosphatidylethanolamine in insulin-sensitive Type I (soleus) and insulin-resistant Type II (EDL) muscle is not known. In the present studies, soleus and EDL muscles were removed from 250–300 g Sprague-Dawley rats, and the fatty acid composition of total and individual phospholipid (PL) species was quantitated. As expected, triglyceride content was increased twofold in soleus muscle. No quantitative differences in the individual PL species or cholesterol content were found between the two muscles. However, a striking difference in PL fatty acid composition was observed in the PC fraction. An increase in 16∶0 with decreases in 18∶0, 18∶1, 22∶5n-3, and 22∶6n-3 (P<0.001 for each) was observed in the PC fraction of EDL compared to that from soleus, consistent with reduced elongation of PC fatty acids. Inhibition of fatty acid oxidation with the carnitine palmitoyl transferase-1 inhibitor, etomoxir, did not alter the fatty acid pattern in either muscle. We conclude that an alteration in PL fatty acid composition consistent with reduced elongation of both saturated and unsaturated fatty acids is observed in Type II muscle. The restriction of these alterations to the PC fraction has important implications. Deceased (June 28, 1996).     

Neutral lipid and fatty acid composition of earthworms (Lumbricus terrestris)

Earthworms (Lumbricus terrestris) were extracted with chloroform-methanol (2∶1) and examined primarily for neutral lipids and fatty acids. TLC showed spots for sterols, hydrocarbons, free fatty acids, phospholipids and pigments but none for glycerides (tri-, di- or mono). Saponification of the crude lipid extract yielded 32% fatty acids, 25% unsaponifiables and 43% unidentified. The lipid contained 3% hydrocarbon and 16% sterols. GLC of the hydrocarbons showed at least 13 components. GLC of the sterol fraction showed peaks corresponding to cholesterol (the major component), γ-sitosterol, β-sitosterol, stigmasterol, campesterol, and ergosterol. GLC showed that at least 38 fatty acids were present, with 18∶1, 18∶2, 18∶0, 20∶1 and 17∶0 predominanting. Abstracted in part from the Ph.D. dissertation of J. Cerbulis, Rutgers, The State University, 1966.     

Alterations in fatty acid composition of tissue phospholipids in the developing retinal dystrophic rat

Alterations in lipid composition occur in the retinal pigment epithelium and photoreceptor cells of the Royal College of Surgeons (RCS) dystrophic rat, a model for inherited retinal degeneration. With respect to lipid composition of nonretinal tissues, the developmental timing of lipid alterations and the incidence of dystrophy are unknown. We determined the fatty acid composition in choline phosphoglycerides (ChoGpl) and ethanolamine phosphoglycerides (EtnGpl) in the brain, liver, and retina from dystrophic RCS rats and from their nondystrophic congenics (controls) at the ages of 3 and 6 wk. At 3 wk, the fatty acid compositions were specific to individual phospholipid classes without any difference between dystrophic and nondystrophic tissues. In plasma phospholipids, there was an age-related increase in the relative contents of monounsaturated and n-3 polyunsaturated fatty acids, with only minor differences between dystrophic and nondystrophic rats. At 6 wk, the fatty acid compositions in ChoGpl and EtnGpl from dystrophic brain and retina were significantly different from those of nondystrophics. The effect of strain on developmental changes in brain fatty acid composition was significant for 18∶0 and 22∶6n−3 in EtnGpl and for 16∶0, 18∶0, 18∶1n−9, and 20∶4n−6 in ChoGpl. The brain ChoGpl fatty acid composition in nondystrophic rats was similar at 6 wk to that of normal rats, and there were almost no postweaning changes in the dystrophics. In retinal phospholipids, the effect of dystrophy was to increase the 20∶4n−6 content in EtnGpl and to decrease 22∶6n−3 in ChoGpl. The 18∶2n−6 and 22∶6n−3 contents in dystrophic liver ChoGpl were also significantly affected, while no difference was observed in the EtnGpl fraction. The dystrophy affected the phospholipid fatty acid developmental changes in a tissue- and class-specific manner. Fatty acid metabolism could be selectively altered in neural and nonneural tissues of developing dystrophic RCS rats.     

Lipid class and fatty acid composition of the boreal soft coral Gersemia rubiformis

Total lipid, phospholipid, and FA composition and distribution of FA between polar lipids (PL) and neutral lipids (NL) were investigated in the boreal soft coral Gersemia rubiformis from the Bering Sea. The total lipids were mostly hydrocarbons and waxes (33.7%) and PL (33.1%). The content of monoalkyldiacylglycerols (9.7%) exceeded the content of TAG (6.7%). PC and PE constituted 31.4% and 25.6% of total phospholipids, respectively. Principal FA were 16∶0, 16∶1n−7, 18∶0, 18∶1n−9, 18∶1n−7, 20∶1n−7, 20∶4n−6, 20∶4n−3, 20∶5n−3 22∶5n−3, 22∶6n−3, 24∶5n−6, and 24∶6n−3. Most n−6 PUFA (52% of total FA) were associated with the PL fraction; this was especially true for arachidonic and tetracosapentaenoic acids. The NL were enriched with mono-, di-, trienoic, and n−3 PUFA. The variation in EPA levels in both NL and PL suggests an origin of this acid from lipids of diatoms consumed by the corals.     

Chemical composition and fatty acid profile of rhea (Rhea americana) meat

The purpose of this work was to determine the proximate composition and fatty acid profiles of the Gastrocnemius pars interna intramuscular fat (IMF) of rhea (Rhea americana) thighs. The birds were bred in captivity, fed with balanced feed (Nutriavestruz Crescimento - Purina) and kept in a pen with grass ad lib. The birds of both sexes used in the research weighed 23 kg on average and were aged about twelve (12) months old. They were subjected to hydric diet (12 h) before slaughtering by electric shock. The rhea meat showed an average moisture, protein, ash and total lipid contents of 74.1%, 22.8%, 1.5% and 1.6%, respectively. It was noticed the predominance of monounsaturated fatty acids (MUFA) in intramuscular fat (IMF), 42.3% and a high percentage of polyunsaturated fatty acids (PUFA), 29.7%. The fatty acids found in higher proportion in rhea IMF were: 18:2n-6 (24.33%), 18: ln-9 (19.25%), 16:0 (13.70%), 22: ln9 (11.40%), 18:0 (10.66%), 15: ln-10 (8.62%), 24: ln-9 (2.90%) and 20:4n-6 (1.72%). The PUFA/SFA and n-6/n-3 ratios were 1.06 and 31.30, respectively. The consumption of rhea meat is a healthy alternative to red meat as it points to a lower susceptibility to cardiovascular diseases caused by the high consumption of fat comparatively to the consumption of meat from most domesticated animals.     

Phospholipid acyl group composition in normal and tumoral nerve cells in culture

We have studied the fatty acid composition of total phosphoglycerides from various types of nerve cells in culture. Primary cell cultures were compared with tumoral cell strains. Glial cells exhibited no characteristic pattern when compared to neurons. Tumoral cell phosphogly cerides contained much higher levels of octadecenoic acid and lower levels of C-20 to C-22 polyunsaturated fatty acids than normal cell phosphoglycerides. This observation seems to be a general feature in tumoral cell membranes. It could be of interest in respect to the membrane fluidity of cancer cells.     

Studies on the changes in fatty acid composition in developing seeds. I.

Oils from castor seeds at different stages of ripening have been studied. The fatty acid composition has been determined by paper chromatography. The ratio of the weight of the kernel to the weight of the seed coat changes from 1.0: 1.24 (14 days) to 1.0:0.48 (45 days) and the oil content of the seed coat is negligible. Amounts of the individual fatty acids in 1 g of kernel as well as in a single seed have been shown. The amounts of ricinoleic, linoleic and stearic acids gradually increase with the ripening of the seeds whereas the amounts of oleic and palmitic acid after an initial increase upto 28 days gradually decrease towards the later stages of growth when the amounts are calculated on the basis of a single seed.     

Lipid class and fatty acid composition of intact peripheral nerve and during wallerian degeneration

Lipid extracts from normal cat, chicken, and beef sciatic nerve were fractionated into their components by combinations of silicic acid, Florisil, DEAE-cellulose, or silicic acid-silicate column chromatography. The constitutent fatty acids of total lipid extracts and of individual lipid classes were qualitatively and quantitatively determined as their methyl esters by gas chromatography. These methods were also applied to lipid extracts from cat sciatic nerve undergoing Wallerian degeneration at 8, 16, 32, and 96 days after section and to chicken sciatic nerve undergoing demyelination due to organophosphate poisoning. All fatty acids were markedly decreased in the total lipids of cat sciatic nerve at 96 days after section and most of these were decreased at 32 days. As early as 8 days after section 16:0, 16:1, 18:2, 20:0, and 20:4 showed decreases, while 18:0, 18:1, 22:1, 22:5, 22:6, and 24:1 did not begin to show decreases until 16 days after section. The decreases in fatty acids were considered to be due to increased catabolism, decreased synthesis, or increased removal of fatty acids from nervous tissue. The fatty acid content of the total lipids of chicken nerve undergoing demyelination resembled that of cat sciatic nerve between 16 and 32 days after section. Myelin lipids, sphingomyelin, cerebrosides, and phosphatidyl ethanolamine (PE) began to decrease as early as 8 days after section in cat sciatic nerve. Phosphatidyl serine (PS) also decreased at this time. Cholesterol, lecithin, and ethanolamine plasmalogen did not begin to decrease until 16 days after section and phosphatidyl inositol (PI) did not decrease until 32 days after section. Triglycerides decreased markedly at 8 days after section gradually returning to normal by 96 days. This was accompanied by a transient increase in free fatty acids and monoglycerides. Cholesterol esters and lysolecithin increased markedly at 8 days after section and were higher than normal levels even at 96 days after section. In chicken sciatic nerve undergoing demyelination after organophosphate poisoning, cerebroside was the only myelin lipid which decreased in amt, while cholesterol esters and diglycerides increased. Sphingomyelin and cerebrosides containing 16:0, 18:0, 18:1, 18:2, 20:0, 22:0, 23:0, 24:0, 24:1 seemed to be most susceptible to degradation or interference in synthesis in degenerating nerve. For the most part, these fatty acids were observed to increase in cholesterol esters, free fatty acids, and, in some instances, triglycerides. The changes in various lipid classes and their constituent fatty acids are discussed in relation to various cellular changes which accompany degeneration.     

Fatty acid composition and cyclopropene fatty acid content of China-chestnuts (Sterculia monosperma,ventenat)

The China-chestnuts (Sterculia monosperma, Ventenat) were examined for their fatty acid composition by gas liquid chromatography, infrared and nuclear magnetic resonance spectroscopy. The oil in nuts contained cyclopropene fatty acids (CPFA) determined as silver nitrate derivatives of their esters. The values (area %) for the major fatty acids as methyl esters were 23.47% C16:0, 1.25% C16:1, 2.56% C18:0, 24.89% C18:1, 18.24% C18:2, 5.40% dihydrosterculic, 3.21% C18:3 + C20:0 and 19.15% sterculic. The proportion of CPFA in the oil did not decrease upon cooking the nuts.     

Knockout of KASIII regulation changes fatty acid composition in canola (Brassica napus)

In contrast to the dominating unsaturated C₁₈ fatty acid, medium‐chain fatty acids (MCFA) are nearly absent in the oil of common canola. Modification of canola oil towards higher contents of C₈ to C₁₄ fatty acids would create new possibilities for oleo‐chemical usages, in both the nutritional and the non‐food sectors. For this purpose, spring oilseed rape (cv. ‘Drakkar’) was genetically modified by introduction of MCFA‐encoding genes from Cuphea species containing approximately 90% MCFA in their seed oil. Two different single constructs involving the 3‐ketoacyl‐acyl carrier protein synthase (KAS)III from C. lanceolata were used, one harbouring the wild‐type gene, ClKASIIIbwt, and the other containing the point‐mutated gene, ClKASIIIbmut, along with two double constructs containing ClKASIIIbmut in combination with a medium‐chain thioesterase gene from C. lanceolata (ClFatB3) or C. hookeriana (ChFatB2). For both single‐gene constructs, a phenotype with an increased content of MCFA was not detected; however, the ClKASIIIbwt transformants produced up to 6.7% palmitic acid (C₁₆). In T2 seeds bearing the ClKASIIIbmut/ClFatB3 double‐gene construct, contents of up to 2.9% capric (C₁₀) and 11.4% palmitic acid were achieved. The best transformant with the gene construct ClKASIIIbmut/ChFatB2 contained 1.4% caprylic acid (C₈) and 7.9% C₁₀, and these results were confirmed in T3 seeds.     

Phospholipid fatty acid composition of various mouse tissues after feeding α-linolenate (18∶3n−3) or eicosatrienoate (20∶3n−3)

The selective incorporation of dietary α-linolenate (18∶3n−3) and its elongation product, eicosatrienoate (20∶3n−3), into various phospholipids (PL) of mouse liver, spleen, kidney, and heart, was examined in a two-week feeding trial by assessing mol % changes in associated fatty acids. Mice were fed fat-free AIN 76A diets modified with either 2 wt% safflower oil (control); 1% safflower and 1% linolenate; or 1% safflower and 1% eicosatrienoate. After linolenate or eicosatrienoate feeding, 20∶4n−6 was reduced by 36–50% in liver phosphatidylcholine (PC) and in liver and spleen phosphatidylethanolamine (PE). Linolenate was minimally incorporated into PL, but was desaturated and elongated to 20∶5n−3, 22∶5n−3, and 22∶6n−3, with notable differences in the quantity of these n−3 derivatives associated with different tissues and PL. Eicosatrientoate was uniquely incorporated into the cardiolipin (CL) pool of all organs. There was also considerable retroconversion of 20∶3n−3 to 18∶3n−3 (PC, PE). Dietary eicosatrienoate may therefore affect metabolism in diverse ways—20∶3n−3, which is retroconverted to 18∶3n−3, may provide substrate for 20∶5n−3 and 22∶6n−3 syntheses, whereas intact 20∶3n−3 may be incorporated into the CL pool. Acyl modifications of CL are known to affect the activity of key innermitochondrial enzymes, such as cytochrome c oxidase. This work was presented in part at the 73rd Annual Meeting of the Federation of American Societies for Experimental Biology, New Orleans, LA, March 19–23, 1989.     

Lipid content and fatty acid composition of 11 species of Queensiand (Australia) fish

The fatty acid composition of 11 species of fish caught off the northeast coast of Australia was determined. No fatty acid profiles have been previously published for fish from this area nor for nine of these species. Although the percentage of polyunsaturated fatty acid (PUFA) was the same as the calculated average for Australian fish (42.3%), the percentage of n−3 fatty acids was lower (24.4±5.4% vs. 30.7±10.1%) and the n−6 fatty acids higher (16.5±4.5% vs. 11.2±5.9%), P<0.001 in each case. The major n−3 PUFA were docosahexaenoic (15.6 ±6.3%) and eicosapentaenoic acid (4.3±1.1%) while the major n−6 PUFA were arachidonic (8.3±3.2%) and n−6 docosatetraenoic acid (3.1±1.3%). The second-most abundant class of fatty acid was the saturates (31.6±3.5%) while the monounsaturates accounted for 17.4±4.3% of the total fatty acids. The monounsaturate with the highest concentration was octadecenoic acid (11.8±2.6%). There was a positive correlation between the total lipid content and saturated and monounsaturated fatty acids (r=0.675 and 0.567, respectively) and a negative correlation between the total lipid content and PUFA (r=0.774).     

FADS1 gene polymorphism(s) and fatty acid composition of serum lipids in adolescents

Polyunsaturated fatty acids (PUFA) influence many physiological functions. Associations have been found between single nucleotide polymorphisms (SNP) in the FADS1 (Fatty acid desaturase 1) gene and the relative abundance of PUFA in serum lipids. This study examines the relationship between two SNPs in the FADS1 gene (rs174546, rs174537) and the fatty acid (FA) composition of serum lipids in adolescents (13–18 years). We used DNA samples (670 children; 336 girls and 334 boys) from the Childhood Obesity Prevalence and Treatment (COPAT) project. Genomic DNA was extracted from peripheral blood leukocytes in whole blood samples. For genotype analysis, TaqMan SNP Genotyping assays (Applied Biosystems) were used. Fatty acid composition of serum lipids was assessed using gas chromatography. The T-statistic and regression were used for statistical evaluations. Minor allele T carriers in both SNPs had significant lower level of palmitic acid (16:0, phospholipids) and arachidonic acid (20:4[n-6], phospholipids) in both sexes. In girls, we found a significant positive association between minor allele T carriers and eicosadienoic acid (20:2[n-6], cholesteryl esters) in both SNPs. Being a minor allele T carrier was significantly positively associated with dihomo-γ-linolenic acid (20:3[n-6], phospholipids) in boys in both SNPs. SNPs (including rs174546, rs174537) in the FADS gene cluster should have impacted desaturase activity, which may contribute to different efficiency of PUFA synthesis.     

Lipid,sterol and fatty acid composition of antarctic krill (Euphausia superba Dana)

The lipid classes, fatty acids of total and individual lipids and sterols of Antarctic krill (Euphausia superba Dana) from two areas of the Antarctic Ocean were analyzed by thin layer chromatography (TLC), gas liquid chromatography (GLC) and gas liquid chromatography/mass spectrometry (GLC/MS). Basic differences in the lipid composition of krill from the Scotia Sea (caught in Dec. 1977) and krill from the Gerlache Strait (caught in Mar. 1981) were not observed. The main lipid classes found were: phosphatidylcholine (PC) (33–36%), phosphatidylethanolamine (PE) (5–6%), triacylglycerol (TG) (33–40%), free fatty acids (FFA) (8–16%) and sterols (1.4–1.7%). Wax esters and sterol esters were present only in traces. More than 50 fatty acids could be identified using GLC/MS, the major ones being 14∶0, 16∶0, 16∶1(n−7), 18∶1(n−9), 18∶1(n−7), 20∶5(n−3) and 22∶6(n−3). Phytanic acid was found in a concentration of 3% of total fatty acids. Short, medium-chain and hydroxy fatty acids (C≤10) were not detectable. The sterol fraction consisted of cholesterol, desmosterol and 22-dehydrocholesterol.     

Altered fatty acid desaturation and microsomal fatty acid composition in the streptozotocin diabetic rat

Streptozotocin diabetes in the rat diminishes the synthesis of both monounsaturated and polyunsaturated fatty acids. Rat liver microsomal fatty acid composition and fatty acid desaturation were studied in the streptozotocin diabetic rat. The major alterations in fatty acid composition found in the diabetic rat were decreased proportions of palmitoleic, oleic and arachidonic acids and an increased proportion of linoleic and docosahexaeneoic acids. These findings, other than the increased docosahexaeneoic acid, probably result from the diminished liver microscomal δ9 and δ6 desaturase activities found in these animals. These changes are not due to the diminished weight gain of the diabetic animals since restricting food intake of control animals to achieve a similar weight gain failed to reproduce either the changes in fatty acid composition or the decrease in fatty acid desaturation. The increased food intake of the diabetic animal may contribute to the altered proportions of linleic and arachidonic acids since limiting food intake in diabetic animals to that of normal controls diminished the magnitude of these changes. Insulin therapy for 2 days not only reverses and overcorrects the diminished desaturase activities, but likewise reverses and overcorrects the altered fatty acid composition, with the exception of the diminished arachidonic aicd levels which are further decreased following insulin therapy. These findings strongly suggest that most of the changes in fatty acid composition in the diabetic rat are indeed caused by the diminished fatty acid desaturase activities.