Interaction of (n−3) and (n−6) fatty acids in desaturation and chain elongation of essential fatty acids in cultured glioma cells

Lipids ◽  
1987 ◽  
Vol 22 (9) ◽  
pp. 613-619 ◽  
Author(s):  
Harold W. Cook ◽  
Matthew W. Spence
Keyword(s):  
Fatty Acids ◽  
Essential Fatty Acids ◽  
Glioma Cells ◽  
Chain Elongation

Geometric and positional fatty acid isomers interact differently with desaturation and elongation of linoleic and linolenic acids in cultured glioma cells

1990 ◽  
Vol 68 (3) ◽  
pp. 653-660 ◽  
Author(s):  
H. W. Cook ◽  
E. A. Emken
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Essential Fatty Acid ◽  
Essential Fatty Acids ◽  
Glioma Cells ◽  
Dienoic Acid ◽  
Chain Elongation ◽  
Positional Isomers ◽  
Trans Isomers ◽  
Trans Bond

A range of geometrical and positional isomers of 18-carbon acyl chains are potential components of diets containing fats from processed vegetable oils or ruminant animals. We have examined seventeen 18-carbon fatty acids, with cis or trans double bonds in positions 8–15, for their effects on desaturation and chain elongation of [1-14C]18:2(n − 6) or [1-14C]18:3(n − 3), primarily to 20:4(n − 6) or 20:5(n − 3) respectively, in cultured glioma cells. All trans monoenoic positional isomers inhibited Δ5 desaturation by approximately 60% when 18:2(n − 6) was the substrate, with no positional discrimination evident; with 18:3(n − 3) as substrate, only the 11- and 12-trans isomers were effective inhibitors of formation of 20:5(n − 3). All cis positional monoene isomers, except for 12-cis 18:1, produced 25–30% inhibition of conversion of 18:2(n − 6) to 20:4(n − 6), but had little effect on the conversion of 18:3(n − 3) to 20:5(n − 3). For dienoic isomers, the presence of a 12-trans bond inhibited formation of both 20:4(n − 6) and 20:5(n − 3) and this was enhanced markedly when the other bond in the dienoic acid was 9-trans. Presence of a 9-trans or 15-trans bond with 12-cis gave little effect except for a slight inhibition of 20:4(n − 6) formation by the 12-cis,15-trans 18:2 isomer. All-cis 20:3(n − 9) blocked Δ5 desaturation, increasing 20:3(n − 6) accumulation from 18:2(n − 6) and suggesting that formation of 20:3(n − 9) from 18:1(n − 9) during essential fatty acid deficiency may further exacerbate the already compromised formation of 20:4(n − 6). Further, the differential effects of various cis and trans isomers on the metabolism of 18:2(n − 6) and 18:3(n − 3) suggest that either Δ5 desaturation is not common in both pathways of conversion of 18:2(n − 6) or 18:3(n − 3) to their primary products or that selective interactions of trans and cis isomers occur when the essential fatty acid substrates are different.Key words: trans isomers, essential fatty acids, desaturation, glioma cells, fatty acid metabolism.

Desaturation and chain elongation of essential fatty acids in isolated liver cells from rat and rainbow trout

Lipids ◽  
1986 ◽  
Vol 21 (3) ◽  
pp. 202-205 ◽  
Author(s):  
Tor-Arne Hagve ◽  
Bjørn O. Christophersen ◽  
Birgit H. Dannevig
Keyword(s):  
Fatty Acids ◽  
Rainbow Trout ◽  
Essential Fatty Acids ◽  
Liver Cells ◽  
Chain Elongation ◽  
Isolated Liver Cells ◽  
Isolated Liver

Fatty Acids: Evolution in Relation to Neurobiology

1993 ◽  
Vol 71 (9) ◽  
pp. 683-683 ◽  
Author(s):  
M. T. Clandinin
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acids ◽  
Acid Content ◽  
Essential Fatty Acids ◽  
Fatty Acid Content ◽  
Chain Elongation ◽  
Brain Membrane ◽  
The Impact ◽  
Long Chain

Metabolism of long-chain polyunsaturated fatty acids derived from 18:2ω−6 and 18:3ω−3 by chain elongation – desaturation is essential for synthesis of complex structural lipids, leukotrienes, thromboxanes, and prostaglandins. These essential fatty acids are required for normal function in developing tissues and appropriate maturation of a wide variety of physiological processes. During development, fetal accretion of long-chain metabolites of ω−6 and ω−3 fatty acids may result from maternal or placental synthesis and transfer or, alternatively, from the metabolism of 18:2ω−6 and 18:3ω−3 to longer chain homologues by the fetus. After birth the infant must synthesize or be fed the very long chain polyunsaturated fatty acids of C20 and C22 type derived from 18:2ω−6 and 18:3ω−3.Metabolism of ω−6 and ω−3 fatty acids utilizes the same enzyme system and is competitive. When levels of dietary ω−3 and ω−6 C18 fatty acids are altered, the levels of metabolites of these precursor fatty acids change in specific brain membranes, influencing membrane lipid dependent functions. For example, a diet unbalanced in very long chain ω−3 and ω−6 fatty acids may increase brain membrane ω−3 fatty acid content when 20:5ω−3 is fed, while decreasing membrane fatty acid content of the ω−6 series of competing fatty acids. As 20:4ω−6 is quantitatively and qualitatively important to brain phospholipid, significant reduction in brain levels of 20:4ω−6 may be less than optimal. The impact of these compositional changes on brain function is not yet clear.The authors in this symposium address how this general area of essential fatty acid metabolism is relevant to the evolution of man, growth and development of fish, function of the retina and neural tissue, cognitive development of infants, and infant nutrition.

scholarly journals Artificial rearing of pigs

1979 ◽  
Vol 41 (1) ◽  
pp. 85-93 ◽  
Author(s):  
M. J. Newport ◽  
J. E. Storry ◽  
B. Tuckley
Keyword(s):  
Fatty Acids ◽  
Crude Protein ◽  
Plasma Lipids ◽  
De Novo ◽  
Essential Fatty Acids ◽  
Medium Chain Triglyceride ◽  
Live Weight ◽  
Dietary Fatty Acids ◽  
Chain Elongation ◽  
Protein Nitrogen

1. Pigs were weaned at 2 d of age and fed on a milk substitute at hourly intervals. They were slaughtered at 28 d of age.2. The diets contained 730 g dried skim-milk and 270 g fat/kg dry matter (DM). Three diets were compared in which the fat was supplied as soya-bean oil (SO) (diet A), equal amounts of SO and medium-chain triglyceride (MCT) (diet H), or 246 g MCT and 24 g SO (diet I)/kg DM. In the latter diet, SO ensured that the diet had an adequate content of essential fatty acids.3. Growth rate (2–28 d of age) was reduced (P < 0.05) by the high-MCT diet (diet I) compared with the medium-MCT diet (diet H), but in comparison with diet A, the differences were not significant (P > 0.05). The feed: gain ratio (g DM consumed/g live-weight gain) was not affected by the type of dietary lipid.4. Diet I increased the proportion of crude protein (nitrogen × 6.25) (g/kg wet weight) in the carcass but did not increase N retention (g/d per kg live weight). The proportion of fat in the carcass was reduced, particularly by diet I (P < 0.001), and was inversely related to an increase mainly in the water content, and to a lesser extent, in the crude protein content of the carcass. The liver weight (g/kg live wt) was greatly increased by MCT (P < 0.01 or P < 0.001).5. Approximately 20, 44 and 80% of the fatty acids in the carcass of pigs on the SO, diet H and diet I respectively could not have been derived from direct deposition of the dietary fatty acids, but rather by de novo synthesis from carbohydrate or elongation of shorter-chain fatty acids.MCT increased the concentrations in the blood, taken 1 h after feeding, of total lipid, phospholipid, cholesterol and cholesterol ester, indicating incomplete oxidation of the caprylic and caprylic and capric acids in MCT by the liver, and their incorporation, after chain elongation, into plasma lipids.

scholarly journals Studies on the metabolism of essential fatty acids in isolated human testicular cells

Reproduction ◽  
2001 ◽  
pp. 881-887 ◽  
Author(s):  
K Retterstol ◽  
TB Haugen ◽  
TN Tran ◽  
BO Christophersen
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Cell Suspension ◽  
Germ Cells ◽  
Essential Fatty Acids ◽  
Minor Component ◽  
Major Fatty Acid ◽  
Chain Elongation ◽  
Human Testis ◽  
Testicular Cells

The essential fatty acid 22:6(n-3) is a minor component of the Western diet, but a major fatty acid in human testis and semen. In mature spermatozoa, the physical and fusogenic properties of the plasma membrane are probably influenced by its particular fatty acid composition. In this study, the synthesis of 22:6(n-3) and 22:5(n-6) was investigated in isolated human testicular cells. [1-(14)C]20:4(n-6), [1-(14)C]20:5(n-3), [1-(14)C]22:4(n-6) and [1-(14)C]22:5(n-3) were incubated in a 'crude' cell suspension (consisting of a mixture of the cells in the seminiferous tubule), and in fractionated pachytene spermatocytes and round spermatids. The esterification of fatty acids in lipid and phospholipid classes and the fatty acid chain elongation and desaturation were measured. The crude cell suspension metabolized the fatty acids more actively than did the fractionated germ cell suspension, indicating that types of cell other than the germ cells are important for fatty acid elongation and desaturation and thus the production of 22:6(n-3). This finding is in agreement with previous results in rats that indicated that the Sertoli cells are the most important type of cell for the metabolism of essential fatty acids in the testis. Some [1-(14)C]20:5(n-3) was elongated to [(14)C]22:5(n-3) in the fractionated germ cells, but very little was elongated further to [(14)C]24:5(n-3),possibly restricting the formation of [(14)C]22:6(n-3). In the fractionated germ cells, the fatty acid substrates were recovered primarily in the phospholipid fraction, indicating an incorporation in the membranes, whereas in the crude cells, more substrates were esterified in the triacylglycerol fraction. In the phospholipids, more radioactivity was recovered in phosphatidylcholine than in phosphatidylethanolamine and more radioactivity was recovered in phosphatidylethanolamine than in phosphatidylinositol or phosphatidylserine.

Unravelling a microbial synergy to boost caproate production via carboxylates chain elongation with ethanol

2019 ◽  
Vol 26 (2) ◽  
pp. 63-71
Author(s):  
Ling Leng ◽  
Ying Wang ◽  
Peixian Yang ◽  
Takashi Narihiro ◽  
Masaru Konishi Nobu ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Microbial Consortia ◽  
Chain Elongation ◽  
Desulfovibrio Vulgaris ◽  
Rrna Gene ◽  
Selective Enrichment ◽  
Microbial Network ◽  
Cost Efficient ◽  
Rrna Gene Sequencing

Chain elongation of volatile fatty acids for medium chain fatty acids production (e.g. caproate) is an attractive approach to treat wastewater anaerobically and recover resource simultaneously. Undefined microbial consortia can be tailored to achieve chain elongation process with selective enrichment from anaerobic digestion sludge, which has advantages over pure culture approach for cost-efficient application. Whilst the metabolic pathway of the dominant caproate producer, Clostridium kluyveri, has been annotated, the role of other coexisting abundant microbiomes remained unclear. To this end, an ethanol-acetate fermentation inoculated with fresh digestion sludge at optimal conditions was conducted. Also, physiological study, thermodynamics and 16 S rRNA gene sequencing to elucidate the biological process by linking the system performance and dominant microbiomes were integrated. Results revealed a possible synergistic network in which C. kluyveri and three co-dominant species, Desulfovibrio vulgaris, Fusobacterium varium and Acetoanaerobium sticklandii coexisted. D. vulgaris and A. sticklandii (F. varium) were likely to boost the carboxylates chain elongation by stimulating ethanol oxidation and butyrate production through a syntrophic partnership with hydrogen (H2) serving as an electron messenger. This study unveils a synergistic microbial network to boost caproate production in mixed culture carboxylates chain elongation.

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