Polyunsaturated fatty acids in plasma and erythrocyte membrane lipids of diabetic children

While insulin is a potent activator of essential fatty acid metabolism, portal hypoinsulinemia is common in Type 1 diabetes. Fatty acids were determined by high-resolution capillary gas-liquid chromatography in plasma and erythrocyte membrane lipids in diabetic children (n = 40) and in age-matched healthy controls (n = 40). In plasma phospholipids, values of linoleic acid (23.00 [2.35] vs. 18.13 [2.54], % by wt, median [range from the first to the third quartile], P<0.000l) and alpha-linolenic acid (0.12 [0.06] vs. 0.07 [0.07], P<0.05) were significantly higher in diabetic children than in controls. In contrast, values of arachidonic acid (10.73 [2.34] vs. 11.53 [2.50], P<0.05) and docosahexaenoic acid (2.23 [0.63] vs. 2.77 [0.98], P<0.01) were significantly lower in diabetic children than in controls. Reduced availability of long-chain polyunsaturates in diabetic children suggests that an enhanced dietary supply of long-chain polyunsaturates may be beneficial.     

The component fatty acids of some marine algal lipids

Twelve marine algae of the Rhodophyta, 17 of the Phaeophyta and 5 of the Chlorophyta were analysed for their fatty acid content. It is possible that the fatty acid distribution may be useful for taxonomic purposes. It is found, that, as in higher plants, there are specific fatty acid distributions in the galactosyl diglycerides, e.g. the ω3 acids with the highest unsaturation are concentrated in the monogalactosyl diglycerides.     

Polyunsaturated fatty acids in serum lipids of reindeer during the close postnatal period

We examined serum fatty acid composition in reindeer during the close postnatal period (from <8 h to 3 weeks) by using maternal serum as a reference point and focusing on the proportions of polyunsaturated fatty acids (PUFAs) in serum lipids. A striking dissimilarity was found in the serum PUFAs between the neonatals and their mothers. In particular, the proportions of linoleic acid (18:2) and α-linolenic acid in serum cholesteryl esters and phospholipids of the newborn reindeer were significantly lower than those of the mothers. Furthermore, serum phospholipids of the newborns had lower arachidonic acid and docosapentaenoic acid but higher docosahexaenoic acid proportions than the maternal phospholipids. Although the proportions of the principal C18 PUFAs were low in reindeer milk, they increased sharply in serum cholesteryl esters and phospholipids of the calves during the first few days after birth. In particular, there were significant positive correlations in the proportions of 18:2 between serum and milk lipids. We conclude that the proportions of the serum C18 PUFAs are low in the newborn reindeer, but they are increased during the close perinatal period by a rate which suggests an efficient mechanism for selective retention of these fatty acids from milk lipids. Accepted: 10 August 1998     

Incorporation of free fatty acids into acylthioesters and lipids of developing sunflower seeds

The synthesis of lipids from radioactive fatty acids in developing sunflower seeds has been examined. Lauric, palmitic, stearic and oleic acids were us     

Very long chain and hydroxylated fatty acids in offspring of somatic hybrids between Brassica napus and Lesquerella fendleri

 Offspring of somatic hybrids between the zero-erucic acid rapeseed cv Hanna and Lesquerella fendleri were analysed regarding their fatty acid profiles. In the first back-cross generation one plant was found that produced a seed containing up to 16.5% erucic acid and 15% eicosaenoic acid (Line 1), as well as a seed having 4.3% ricinoleic acid (Line 2). This was interpreted as due to a contribution of elongase and hydroxylase genes from the L. fendleri genome since these two fatty acids are not produced in the recipient rapeseed cultivar Hanna. Crosses between Line 1 and cv Hanna resulted in the production of seeds with 35% erucic acid (F₂). Furthermore, crosses between the F₂ plants and the rapeseed cultivar Gulle, producing 35% erucic acid in the seeds, resulted in F₃ seeds with 48% erucic acid. The highest amount of erucic acid, 61.5%, was found in the F₆ generation after crossing Line 1 with a high erucic acid rapeseed line, HEAR, followed by self-fertilisation for two generations. When performing Southern-blot analysis on the F₆ plants, seven of the nine analysed plants hybridised with the L. fendleri species-specific repetitive probe. The presence of the hydroxylase gene was also observed in the F₆ generation of Line 1 according to Southern-blot analysis. Hybridisation with a hydroxylase probe was seen although no hydroxy fatty acids could be detected in any of the F₆ plants. In parallel, Line 2 was crossed with HEAR cv Gulle and self fertilised. No hydroxy fatty acids were detected in the F₂ generation of Line 2 and no specific hybridisation patterns could be found in the Southern-blot analysis. Received: 12 December 1998 / Accepted: 4 January 1999     

Role of fatty acids in cold adaptation of Antarctic psychrophilic Flavobacterium spp.

Cold-loving microorganisms developed numerous adaptation mechanisms allowing them to survive in extremely cold habitats, such as adaptation of the cell membrane. The focus of this study was on the membrane fatty acids of Antarctic Flavobacterium spp., and their adaptation response to cold-stress. Fatty acids and cold-response of Antarctic flavobacteria was also compared to mesophilic and thermophilic members of the genus Flavobacterium. The results showed that the psychrophiles produced more types of major fatty acids than meso- and thermophilic members of this genus, namely C_15:1 iso G, C_15:0 iso, C_15:0 anteiso, C_15:1 ω6c, C_15:0 iso 3OH, C_17:1 ω6c, C_16:0 iso 3OH and C_17:0 iso 3OH, summed features 3 (C_16:1 ω7cand/or C_16:1 ω6c) and 9 (C_16:0 10-methyl and/or C_17:1 iso ω9c). It was shown that the cell membrane of psychrophiles was composed mainly of branched and unsaturated fatty acids. The results also implied that Antarctic flavobacteria mainly used two mechanisms of membrane fluidity alteration in their cold-adaptive response. The first mechanism was based on unsaturation of fatty acids, and the second mechanism on de novo synthesis of branched fatty acids. The alteration of the cell membrane was shown to be similar for all thermotypes of members of the genus Flavobacterium.     

Olfactory discrimination of short chain fatty acids in rats with large bilateral lesions of the olfactory bulbs

Rats trained preoperatively to discriminate between acetic acid and caproic acid and between acetic acid and propionic acid were tested for their memory of these tasks and ability to discriminate between these odorants and between the enantiomers of carvone after receiving large bilateral bulbar lesions that included most of the fatty acid responsive areas identified in prior physiological studies. Concentrations of acid odorants were varied to insure that discrimination was based on the qualitative difference between acids. Experimental rats performed somewhat poorer than controls on the memory test but had no significant deficits in performing the acid discrimination tasks or discriminating between the enantiomers of carvone. These results demonstrate that removal of most bulbar sites identified as responsive to fatty acids and the consequent disruption of patterned input to the bulb is largely without effect on discriminating odor qualities of structurally similar acids.     

Silver ion chromatography of lipids and fatty acids

Silver ion chromatography as applied to the analysis of lipids is reviewed. Thin-layer, column, high-performance liquid and supercritical fluid chromatography in the silver ion mode are included. The lipid types covered are fatty acids, triacylglycerols and complex lipids. Separations are divided into those according to number, geometry and position of double bonds, as well as acyl positional isomers for triacylglycerols. The mechanism of silver ion chromatography is discussed in relation to recent studies using silver ion high-performance liquid chromatographic methodology.     

Yolk lipids and their fatty acids in the wild and captive ostrich (Struthio camelus)

A comparative study has been made of the major lipid fractions and their fatty acid compositions in the yolk of eggs from ostriches under wild and farmed conditions. There were no differences in the lipid contents and proportions of the lipid fractions between the two groups of yolks. In both groups of yolks triacylglycerol and phospholipid were the major fractions. In the eggs from the wild ostriches, all the lipid fractions displayed substantial concentrations of C18 polyunsaturated fatty acids, triacylglycerol being particularly rich in linolenic acid and phospholipid rich in linoleic acid; phospholipid displayed substantial concentrations also of C20 and C22 polyunsaturates. There were considerable differences in the fatty acid compositions between the yolks. Those from the farmed birds displayed lower proportions of C18 polyunsaturates, particularly linolenic acid, throughout the lipid fractions. Compensatory increases were displayed most obviously in the concentrations of oleic acid and palmitoleic acid as well as other acids. The distinctive and extensive changes in fatty acid composition, particularly relating to the polyunsaturates, are discussed with respect to overall dietary requirements and specificities for embryo metabolism and possible effects on reproductive performance.     

Biochemistry of radioiodinated free fatty acids

Summary Radioiodinated free fatty acids have been developed to study myocardial metabolism non-invasively in man. In the present study the distribution of radiolabeled lipids in the myocardium and in arterial and coronary sinus blood was evaluated following injection of three commonly used iodinated fatty acids in fasted (n = 5) and lactate loaded (n = 3) dogs. Five minutes after simultaneous i.v. injection of radioiodinated 17-I-heptadecanoic acid (IHDA),15-(p-I-phenyl) pentadecanoic acid (IPPA) and 15-(p-I-phenyl)-3,3-dimethylpentadecanoic acid (DMIPPA) a biopsy specimen and samples of arterial and coronary sinus blood were taken. After extraction and TLC the relative distribution of radioactivity in the aqueous phase (containing the oxidation products), pellet and organic phase was calculated. The organic phase was further divided into phospholipids, diglycerides, free fatty acids, triglycerides and cholesterolesters. Seventy two percent of IHDA was oxidized, 36% of IPPA and 7% of DMIPPA. The organic phase consisted primarily of triglycerides and phospholipids. The ratios of triglycerides to phospholipids were about the same for IHDA, IPPA and DMIPPA (0.58, 0.65 and 0.50, respectively). Free IHDA in tissue samples was low (4%) and elevated for IPPA and DMIPPA, (17% and 37%). During lactate loading triglycerides were higher for all three fatty acids. For IHDA and IPPA this increase was paralleled by a decrease in the aqueous phase, in case of DMIPPA the aqueous phase remained the same. Five minutes after injection most of the organic phase of both arterial and coronary sinus blood consisted of the injected fatty acids, the aqueous phase contained oxidation products. There were only minor differences during lactate loading. During the evaluation of scintigraphic patterns of the radioiodinated fatty acids under normal conditions (eg at rest) and during elevated lactate levels (eg during exercise) the differences in distribution must therefore be considered.     

Seasonal changes in oleosomic lipids and fatty acids of perennial root nodules of beach pea

Seasonal changes in the fatty acid composition of phospholipids (PL), monoglycerides (MG), diglycerides (DG), free fatty acids (FA) and triglycerides (TG) separated from oleosomes (lipid bodies) of perennial root nodules of beach pea (Lathyrus maritimus) were analysed. Thin layer chromatography (TLC) revealed that PL and MG are the major lipids in nodule oleosomes. The fatty acid profile and overall double bond index (DBI) varied among lipid classes depending upon the season. High DBI in PL and MG found during late winter and early spring indicated that they may play a major role in winter survival and regeneration of perennial nodules. The DBI of DG was high at the end of the fall season and the DBI of FA and TG was high in summer months. The dominant fatty acids are C16:0 followed by C18:0 and C18:1. The levels of many unsaturated fatty acids such as C18:1, C18:2 and C18:3 increased while saturated fatty acid C18:0 decreased during winter. These unsaturated fatty acids possibly play an important role in the protection of nodule cells from cold stress. Nodules seem to retain some fatty acids and selectively utilize specific fatty acids to survive the winter and regenerate in spring.     

Enzyme-assisted extraction of fucoxanthin and lipids containing polyunsaturated fatty acids from Undaria pinnatifida using dimethyl ether and ethanol

A novel method for the efficient extraction of fucoxanthin and lipids containing polyunsaturated fatty acids (PUFAs) from the brown seaweed Undaria pinnatifida was developed and demonstrated at a laboratory scale. U. pinnatifida, also known as Wakame, contains a number of biologically active lipophilic compounds, particularly fucoxanthin, which has anti-oxidant, anti-cancer, anti-obesity and anti-inflammatory properties. The yield of fucoxanthin and lipids containing PUFAs was determined by extraction from wet and freeze-dried seaweed using dimethyl ether (DME) and ethanol and from enzyme-pretreated seaweed using the same solvents. The highest yields of fucoxanthin (94%) and lipids (94%) rich in PUFAs were obtained from fresh (wet) U. pinnatifida by enzyme pre-processing, followed by extraction using DME with ethanol as a co-solvent. In comparison, ethanol extraction resulted in lower extraction yields for both fucoxanthin (86%) and lipids (73%) under the conditions described. Enzyme pre-processing using alginate lyase resulted in the hydrolysis of cell wall polysaccharides, resulting in high extraction yields. The hydrolysis time, pH and temperature were found to be the most important parameters for the enzyme pre-processing step and for minimizing fucoxanthin losses due to oxidative degradation. The removal of water-soluble compounds (polysaccharides) following the enzyme pre-treatment prior to DME extractions doubled the throughput and maximized the yield. The residual biomass was colorless or a pale-brown color after the DME extraction, which indicated the highly effective extraction of fucoxanthin. The PUFA content and fucoxanthin levels were not affected by the enzyme or extraction using the described enzyme-assisted DME + ethanol co-solvent process.     

Influence of vitamin E on the levels of fatty acids and MDA in some tissues of diabetic rats

This study was performed to determine whether vitamin E supplementation in streptozotocin-induced diabetic rats treated with insulin could affect the levels of fatty acid composition and malondialdehyde (MDA) of brain, liver and muscle tissues. Thirty Wistar albino rats were used during the experiments. They were randomly divided into three groups, each consisting of six individuals. The first group was diabetic, the second was control, and the third was diabetic but fed vitamin E. The level of stearic acid in brain tissues decreased (p<0.05) in the second and the third groups as compared to the first group. The percentage of arachidonic and polyunsaturated fatty acids slightly decreased (p<0.05) in the diabetic group in comparison to the second and third groups. The proportion of docosahexaenoic acid significantly increased (p<0.01) in the second and third groups in contrast to the first group. The level of docosatrienoic was slightly higher (p<0.05) in the third group than in other groups. In the liver tissues, the proportion of stearic, oleic and total monounsaturated fatty acids was slightly higher (p<0.05) in the first group than in the other groups. The level of arachidonic, docosahexaenoic, unsaturated and total polyunsaturated fatty acid slightly increased (p<0.05) in the second and third groups as compared to the first group. The level of myristic and stearic acids in muscle tissue slightly increased (p<0.05) in the first group as compared to the second and third groups. The proportion of arachidonic, docosahexaenoic and unsaturated fatty acids slightly increased (p<0.05) in the second and third groups relative to the first group. The amount of MDA was slightly higher in the diabetic group than in the other groups in all tissues. The results indicate that vitamin E supplementation, in experimental diabetes could play a role in controlling the oxidative status and altered fatty acid metabolism in tissues, thereby maintaining favourable fatty acid distribution in the tissues affected by diabetic complications.     

Nonesterified fatty acids and lipid peroxidation

Oxygen free radicals damage cells through peroxidation of membrane lipids. Gastrointestinal mucosal membranes were found to be resistant to in vitro lipid peroxidation as judged by malonaldehyde and conjugated diene production and arachidonic acid depletion. The factor responsible for this in this membrane was isolated and chemically characterised as the nonesterified fatty acids (NEFA), specifically monounsaturated fatty acid, oleic acid. Authentic fatty acids when tested in vitro using liver microsomes showed similar inhibition. The possible mechanism by which NEFA inhibit peroxidation is through iron chelation and iron-fatty acid complex is incapable of inducing peroxidation. Free radicals generated independent of iron was found to induce peroxidaton of mucosal membranes. Gastrointestinal mucosal membranes were found to contain unusually large amount of NEFA. Circulating albumin is known to contain NEFA which was found to inhibit iron induced peroxidation whereas fatty acid free albumin did not have any effect. Addition of individual fatty acids to this albumin restored its inhibitory capacity among which monounsaturated fatty acids were more effective. These studies have shown that iron induced lipid peroxidation damage is prevented by the presence of nonesterified fatty acids.     

Total fatty acids of hair lipids in cystic fibrosis

In a preliminary study, total fatty acids of lipids removed from hair of subjects of either sex with cystic fibrosis (n = 17; average age 8.3 years) and controls (n = 24; average age 9.1 years) were analyzed by gas chromatography. In contrast to the blood lipids in cystic fibrosis which display various fatty acid changes as a depression in 18:2 and increases in 16:0, 16:1, and 18:1, such profiles did not occur with the hair lipids. With the latter, total fatty acids in cystic fibrosis showed decrements in 18:1 and in the lesser concentrations of 20:1 and members below C14 as compared to the respective control series.     

Incorporation and modification of dietary fatty acids in gill polar lipids by two bivalve species Crassostrea gigas and Ruditapes philippinarum

Two bivalve species Crassostrea gigas and Ruditapes philippinarum were fed eight weeks with three mono-specific algae diets: T-Isochrysis galbana, Tetraselmis suecica, Chaetoceros calcitrans, selected on the basis of their polyunsaturated fatty acid (PUFA) composition. The incorporation and the modification of dietary fatty acids in C. gigas and R. philippinarum gill lipids were analysed and compared. Essential PUFA (20:4n-6, 20:5n-3 and 22:6n-3) and non-methylene interrupted PUFAs (known to be synthesised from monounsaturated precursors) contents of gill polar lipid of both species were greatly influenced by the dietary conditioning. Interestingly, oysters and clams responded differentially to the mono-specific diets. Oysters maintained higher 20:5n-3 level and higher 22:2j/22:i and n-7/n-9 ratio in gill polar lipids than clams. To better discriminate dietary and species influences on the fatty acid composition, a Principal Component Analysis followed by a MANOVA on the two most explicative components was performed. These statistical analyses showed that difference in fatty acid compositions attributable to species were just as significant as the diet inputs. The differences of gill fatty acid compositions between oysters and clams are speculated to result of an intrinsic species characteristic and perhaps of a group characteristic: Fillibranch vs. Eulamellibranch.     

Low contribution of n-3 polyunsaturated fatty acids to plasma and erythrocyte membrane lipids in diabetic young adults

Hypoinsulinemia characteristic to type 1 diabetes may theoretically inhibit the conversion of essential fatty acids to their longer-chain metabolites. Fatty acids were determined in plasma and erythrocyte membrane lipids in young diabetic adults (n=34) and in age-matched healthy controls (n=36). Values of linoleic acid (56.01 [5.02] versus 51.05 [7.32], % by wt, median [range from the first to the third quartile], P<0.00l) and arachidonic acid (AA) (11.17 [2.98] versus 9.69 [1.95] P<0.001) were significantly higher in diabetic subjects than in controls. However, alpha-linolenic acid values did not differ, and docosahexaenoic acid (0.43 [0.12] versus 0.57 [0.29], P<0.01) values were significantly lower in diabetic than in control subjects. Significant inverse correlations were found between AA and hemoglobin A(1c) values in the phospholipid (r=-0.40, P<0.05) and sterol ester (r=-0.40, P<0.05) fractions. The data obtained in the present study suggest that the availability of n-3 long-chain polyunsaturated fatty acid may be reduced in young diabetic adults.