Comparison of muscle lipid composition between marine and landlocked forms of sockeye salmon (Oncorhynchus nerka)

• 1.1. Total lipid content, and lipid class and fatty acid compositions in the muscle were analyzed for marine and landlocked forms of sockeye salmon.
• 2.2. Little difference was found for the total lipid content in the muscle between both forms.
• 3.3. Triglycerides were higher in the marine form than those in the landlocked one, but phospholipids showed an opposite tendency.
• 4.4. In the fatty acid composition of total lipid, percentages of 20:1 and 22: 6n-3 were higher in the marine form, while 18:2, 18:3n-3, 18:4n-3 and 20:4n-3 were more abundant in the landlocked one. Fairly high levels of 22:1 were present only in the marine form.

     

Blood lipids of the small octopus,Octopus tehuelchus (mollusca,cephalopoda) at different stages of sexual maturation

• 1.1. The lipid and fatty acid composition from the plasma and hemocytes in Octopus tehuelchus at different stages of sexual development, was determined.
• 2.2. The highest content of lipids was found in females engaged in egg development, and the lowest in post-spawning and brooding females. Highest levels occurred during the autumn season in both sexes.
• 3.3. Changes were mainly due to triacylglycerols and diacylglyceryl ethers.
• 4.4. The plasma fatty acid composition did not demonstrate significant changes at different stages of maturation. The arachidonic acid (20:4 ω 6) was present at surprisingly high levels.

     

Locality-dependent concentrations of bromophenols in Lanice conchilega (Polychaeta: Terebellidae)

• 1.1. At 37 stations in the English Channel and the southern North Sea concentrations of four brominated phenols in Lanice conchilega were determined using ECD equipped capillary gas chromatography: 2,4-dibromophenol, 2,6-dibromo-4-methylphenol, 2,4,6-tribromophenol, 3,5-dibromo-4-hydroxybenzaldehyde.
• 2.2. Concentrations in worms of the southern North Sea were generally below 1 μg/g wet wt.
• 3.3. Levels were slightly raised in worms of sheltered shores, those of 3,5-dibromo-4-hydroxybenzaldehyde were increased in subtidal populations.
• 4.4. Concentrations in L. conchilega of Brittany were considerably higher than those in worms of the Frisian Islands, North Sea; they deviated from the latter by factors of 3, 16, 4, 4, respectively.
• 5.5. The reasons for the conspicuous differences are hitherto unknown; three explanations are suggested.

     

Fatty acid profile of the digestive gland and mantle in the bivalve Macoma balthica

• 1.1. Digestive gland and mantle fatty acids were studied in spring and summer in the bivalve Macoma balthica off the southern coast of Finland. The presence of lipids was also examined histochemically in various clam tissues.
• 2.2. the neutral lipid content of the digestive gland increased ca 4.5-fold during the annual growth period.
• 3.3. Neutral lipid fatty acids of the digestive gland, of which palmitoleic, eicosapentaenoic and palmitic acids were predominant, were clearly distinguished from phospho- and glycolipid fatty acids.
• 4.4. The degree of unsaturation of phospholipid fatty acids was higher in the cold season both in the digestive gland and mantle, mainly due to the titer of eicosapentaenoic acid.

     

Changes of the fatty acid composition in smolts of masu salmon (Oncorhynchus masou), associated with desmoltification and sea-water transfer

• 1.1. Tissue lipid compositions of desmoltified yearlings of masu salmon (Oncorhynchus masou) obtained by keeping smoltified fish in fresh water, were examined and compared to those of smoltified fish before and after transfer to sea-water (SW).
• 2.2. Lipid contents of muscle, liver, gut and gills of desmolts tended to increase compared to those of initial smolts.
• 3.3. The increased proportion of triacylglycerol (TG) and decreased proportion of phospholipids (PL) characterized the tissue lipids of desmolts.
• 4.4. Liver and muscle lipids showed no distinct differences both in content and proportion between initial and SW smolts, but gut and gill lipids of SW smolts decreased in content accompanied by a decrease of TG and an increase of PL in proportion.
• 5.5. Excepting muscle non-polar lipids, tissue lipids of desmolts contained more mono-unsaturated fatty acids and saturated fatty acids and less polyunsaturated fatty acids (PUFA), especially (n-3) PUFA such as 22:6(n-3), than those of initial and SW smolts.
• 6.6. No large differences in fatty acid composition were seen between initial and SW smolts except for the gut.
• 7.7. The proportion of (n-3) PUFA in the gut of SW smolts was higher than that of initial smolts.
• 8.8. The results indicated that masu salmon smolts can modify their lipid metabolism to adapt to ambient salinity changes. The proportion of (n-3) PUFA particularly in polar lipids, or in osmoregulatory organs such as gut and gills, was seen to be critical in lipid types of freshwater- or sea-water-adapted fish.

     

Comparative study on the fatty acid and lipid composition of four marine fish larvae

• 1.1. Fatty acid and lipid class composition were determined in larvae of four marine species: Atlantic halibut (Hippoglossus hippoglossus L.), plaice (Pleuronectes platessa), cod (Gadus morhua) and turbot (Scophthalmus maximus) at hatching and prior to first feeding.
• 2.2. Total fatty acid content decreased in the four species with up to 50% reduction in one of the halibut groups. Docosahexanaoic acid (22:6 n-3) was especially utilized.
• 3.3. Low lipid utilization was found in turbot in relation to the other three species.
• 4.4. Water environmental temperature may explain some of the differences in the fatty acid utilization and the source of metabolic energy between cold water species (halibut, cod, and plaice) and temperate species (turbot), in the period from hatching to prior to first feeding.
• 5.5. Relative amounts of neutral lipids and phospholipids were similar in plaice, cod and halibut, approximately 25% and 75% of total lipids, respectively, and were approximately constant during the yolk-sac stage. Neutral lipids were dominant for turbot at hatching, accounting for 53–55% of the total lipids, while phospholipids predominated prior to first feeding, being 56–59%.
• 6.6. Phosphatidylcholine was catabolized in halibut, plaice and cod but not in turbot, while phosphatidylethanolamine tended to be synthesized in all four species.

     

Lipid composition of the red and green forms of Actina equinia from the black sea

• 1.1. The fatty-acid composition of the red and green forms of Actinia equina from the Black Sea have been determined by methods involving silver-ion HPLC and GC-MS.
• 2.2. The fatty acid compositions of both forms of A. equina resemble those of most marine invertebrates. Substantial amounts of C₂₀ and C₂₂ polyunsaturated fatty acids were found.
• 3.3. Balck Sea Actenia equina contains a large amount of plasmalogens, mainly phospotidylcholine and phosphatidylserine plasmalogens.
• 4.4. The red form of A. equina contains more arachidonic acid in glycolipid fraction and more phosphatidylethanolamine and its plasmalogen, while the green from contains more sphingomyelin. These differences are an indication that the species A. equina can be divided into two subspecies—green and red.

     

Phospholipid and fatty acid composition of the freshwater sponge Euspongilla lacustris from the volga river estuary

• 1.1. Phospholipids of the freshwater sponge Euspongilla lacustris from the Volga river estuary were examined.
• 2.2. The freshwater sponges belonging to the family Spongillidae were shown to contain demospongic fatty acids.
• 3.3. Composition of fatty acids in phospho-, glyco- and neutral lipid fractions was studied.

     

Presence of an essential polyunsaturated fatty acid in intradigestive bacterial symbionts of a deposit-feeder echinoid (Echinodermata)

• 1.1. Fatty acids were isolated from bacteria of the family Beggiatoaceae and closely related to the genus Thiothrix. These bacteria are symbionts that live in the gut of Echinocardium cordatum.
• 2.2. Ten pronounced chromatographic peaks were observed that correspond to 14:0, 15:0, 15:0, 16:0, 16:1, 17:0, 18:0, 18:1, 18:3 and 19:0 fatty acids.
• 3.3. The fatty acid 18:3 had a retention time and mass spectrum identical to those of linolenic acid.
• 4.4. The presence of an essential fatty acid has never before been reported in a non-photosynthetic organism. This essential fatty acid in the symbiotic bacteria could be of nutritional importance for their echinoid host.
• 5.5. The presence of this essential fatty acid supports a phylogenetic affinity between Beggiatoaceae and Cyanobacteria that are the only bacteria known to synthetize linolenic polyunsaturated fatty acid (PUFA).

     

Lipid digestion in cod (gadus morhua)

• 1.1. Cod, 2.6–3.4 kg. were fed a mixed diet of sprat, capelin oil and wheat flour.
• 2.2. Lipids from the feed, stomach and four intestinal segments were separated into tri-, di- and monoglycerides and free fatty acids and analysed by GLC.
• 3.3. All lipolytic products were concentrated in 14:0, 16:0 and 18:0, up to 60% and extremely low in the ω-3 fatty acids.
• 4.4. Residual triglycerides contained 80% of saturated and monoenoic fatty acids.
• 5.5. Linoleic acid increased from 2% in feed TG to 10% in TG of the rectum.

     

Association of cytosolic lipids with fatty acid synthase from lactating mammary gland

• 1.1. Membrane-free cytosol contained over 4% of both the total lipids and phospholipids present in homogenates of lactating rat mammary gland, and much of this lipid was associated with a high molecular weight complex isolated from cytosol by gel exclusion chromatography or by density gradient centrifugation.
• 2.2. This complex principally consisted of polypeptides with apparent molecular weights of 220 and 116kDa. Lipids associated with this complex were transferred to endoplasmic reticulum and to intracellular lipid droplet precursors of milk lipid globules upon incubation in a cell-free system.
• 3.3. This lipoprotein complex was abundant in cytosol from lactating mammary gland, but was diminished in amount in cytosol from involuted mammary glands. The 220 kDa constituent of this complex was identified as the monomer of fatty acid synthase.
• 4.4. These results suggest that fatty acid synthase complex in lactating mammary gland may function in transfer of lipids necessary for formation or growth of lipid droplet precursors of milk lipid globules.

     

Modulation of mitochondrial ATPase sensitivity to inhibitors and stimulators by diet-induced changes in membrane lipid

• 1.1. Weanling rats were fed diets differing in fatty acid composition to determine if changes induced in cardiac mitochondrial membrane structural components alter the sensitivity of mitochondrial ATPase to inhibition by oligomycin and stimulation by 2,4-dinitrophenol.
• 2.2. Mitochondrial ATPase assayed in situ within the mitochondrial membrane isolated from animals fed diets higher in fatty acids of longer chain length, exhibited greater oligomycin sensitivity and lower 2,4-dinitrophenol-induced stimulation.
• 3.3. Concomitant diet-induced changes occur in the fatty acid, composition of phosphatidylcholine, phosphatidylethanolamine and cardiolipin, increasing overall length of fatty-acyl tails in the membrane phospholipids.
• 4.4. Diet fat mediated alterations in oligomycin sensitivity of mitochondrial ATPase and membrane fatty acid chain length suggest that _vivo changes in thickness of the lipid bilayer may alter mitochindrial ATPase functions.
• 5.5. The present study extends the concept that dietary fat affects mitochondrial membrane structure and function by demonstrating that the membrane-dependent sensitivity of mitochondrial ATPase to inhibitors and stimulators may be modulated by dietary fat.

     

Effects of soluble corn bran hemicellulose on lipid metabolism

• 1.1. Since soluble corn bran hemicellulose (CBH) was found to reduce serum cholesterol level in the rat fed with a high cholesterol diet, rats were fed with diets containing orotic acid (OA) to investigate the effect of CBH on lipid metabolism.
• 2.2. Hepatic lipid accumulation induced by OA was reduced by feeding with CBH in rats. The reduction was not due to inhibition of intestinal absorption of OA by CBH.
• 3.3. Administration of acetate or propionate, colonie fermentation products of CBH, tended to alleviate the hepatic lipid accumulation by OA in rats.
• 4.4. OA feeding decreased activities of some hepatic enzymes involved in fatty acid synthesis except for acetyl CoA carboxylase. The decreases were reversed by the concurrent feeding of CBH.

     

Gut microflora can modify fatty acid composition in liver and egg yolk lipids of laying japanese quail (Coturnix coturnix japonica)

• 1.1. The influence of the gut microflora on lipid metabolism was investigated in germ-free (GF) and conventional (CV) laying Japanese quail.
• 2.2. Serum and egg yolk cholesterol concentrations showed comparable values in both GF and CV environments.
• 3.3. The fatty acid compostion of liver lipids was modified by the presence of gut microflora. Notably, in the presence of the gut microflora, proportion of oleic acid was reduced and conversely, stearic and linoleic acids were enhanced.
• 4.4. In egg yolk lipids, the proportion of myristoleic and palmitoleic acids was significantly lowered and that of stearic acid was significantly enhanced by the presence of the gut microflora, though the difference was very small.
• 5.5. It was suggested that oleic acid could be easily either hydrogenated to stearic acid or desaturated to linoleic acid by the action of the gut microflora in Japanese quail.

     

The reproduction strategy of oyster ostrea edulis L. from the biochemical point of view

• 1.1. Influence of the biochemical composition of food (four species of micro-algae and one mixture) on the biochemical composition of gonads and larvae of O. edulis (total protein, lipid, carbohydrate, ash content, neutral and polar lipid class composition, amino acid composition and fatty acid composition of total, neutral and polar lipids) and the size of newly released larvae have been investigated.
• 2.2. Precentage of total lipids and triacylglycerols in gonads depends on that in algae (r = 0.52 and 0.69 accordingly).
• 3.3. Gonads rich in lipids had a higher level of triacylglycerols, phospholipids, polar lipids and a lower value of the ratio phosphatidylethanolamine/phosphatidylcholine (PE/PC) than gonads with a low lipid content.
• 4.4. Amino acid composition of gonads depends on that of food, in this case, essential acids are preferentially accumulated (Asp acid, Ser, Ala, Cys, Tyr and Pro) and two non-essential (Thr and Lys).
• 5.5. Fatty acid composition of total lipids of gonads was rather stable; except for the two essential acids 20:523 and 22:6w3, their percentage depends on that of food r = 0.65 and 0.65 accordingly). Fatty acid composition of neutral lipids was more diverse (in number and degree of variety) as compared to polar lipids.
• 6.6. Larvae released from oysters with gonads rich in lipids had a higher percentage of lipids, triacylglycerols, size and a lower ash percentage and value of ratio PE/PC, as compared to larvae from gonads with low lipid content. Total lipid and triacylglycerol contents in gonads correlate rather well with those in larvae (r = 0.77 and 0.47 accordingly).
• 7.7. Phospholipid class composition of larvae strongly depends on that of gonads. All the correlations are high and positive in character (except for phosphatidylinositol).
• 8.8. Amino acid composition of larvae depends on that of gonads and, as in the case with gonads, the same essential acids are accumulated in the first place.
• 9.9. Fatty acid composition of total lipids of newly released larvae was rather stable and independent on that of gonads except for total polyunsaturated acids (r = 0.70) and 20:5w3 (r = 0.65). Fatty acid composition of neutral lipids was lesser diverse (in number and degree of variation) as compared to polar lipids.

     

The pathway of the biosynthesis of non-methylene-interrupted dienoic fatty acids in molluscs

• 1.1. The metabolic fate of 1-¹⁴C-acetate administered to the marine bivalve mollusc Mytilus edulis was investigated.
• 2.2. The active incorporation of the label in 20:2 non-methylene-interrupted dienoic (NMID) fatty acids was found.
• 3.3. Acetate incorporation patterns and specific radioactivity of mussel acids suggest that 22:2Δ7,13 and 22:2/gD7,15 arose by C₂ elongation of 20:2Δ5,11 and 20:2Δ5,13 respectively.
• 4.4. The proposed pathway of NMID fatty acid biosynthesis in molluscs is discussed.

     

Disruption of endothelial barrier function: relationship to fluidity of membrane extracellular lamella

• 1.1. Endothelial cells were cultured in tissue culture flasks or on microcarrier beads and labeled with a lipid specific spin-label.
• 2.2. Exposure of endothelial cells to benzyl alcohol caused a dose- and time-dependent increase in membrane fluidity using electron spin resonance (ESR). Maximum fluidity was reached after a 5-min exposure to 100 mM benzyl alcohol.
• 3.3. Albumin permeability across endothelial cells cultured on micropore filters was used as an indication of endothelial monolayer integrity.
• 4.4. A significant increase in permeability occurred with 50 mM benzyl alcohol. Maximal albumin permeability was reached after a 5-min exposure to 100 mM benzyl alcohol.

     

Lipid composition of three geographical sources of brine shrimp nauplii (Artemia sp.)

• 1.1. Percentage of triacylglycerols (TG), free fatty acids (FFA) and phospholipids (PL) in the total lipids, the fatty acid composition of each of these lipid classes, and the percentage of cholesterol were determined by gas chromatography in three geographical sources (San Francisco Bay, SFB; Chinese, CH; Colombian, COL) of brine shrim (Artemia sp.) nauplii.
• 2.2. There were no significant differences among sources of brine shrimp in total lipids, TG or FFA with means for all sources of 17.8, 65.8 and 10.9%, respectively. Percentage of phospholipid was significantly higher in SFB and CH sources of brine shrimp, 25.1 and 26.5%, respectively, than in COL 18.3%.
• 3.3. Marked differences in percentages of 18:3 (n-3) (linolenic acid) and 20:5 (n-3) (eicosapentaenoic acid or EPA) were found among brine shrimp sources, and concentration of these two fatty acids were usually inversely related within sources. The CH source contained higher concentrations of EPA ( > 9.0%) than the COL and SFB sources (< 5.0%) in all three lipid classes analyzed. No 22:6 (n-3) (docosahexaenoic acid or DHA) was found in any brine shrimp source.
• 4.4. Fatty acid compositions of the TG and PL were similar and did not differ among sources of brine shrimp, while the FFA had a lower percentage of polyunsaturated fatty acids, but was similar among sources of brine shrimp.
• 5.5. Differences in n-3 fatty acid composition indicated a difference in nutritional quality among sources of brine shrimp for feeding larval fish.

     

Fatty acid composition of five zoantharia from the senegalese coast: Palythoa Dartevellei pax,P. monodi Pax,P. Variabilis duerden,P. Senegalensis pax and their associated zooxanthellae and P. senegambiensis carter and its commensal,the decapoda diogenes ovatus miers

• 1.1. The quantitative and qualitative fatty acid composition of five Palythoa from the Senegalese coast and their associated organisms: Zooxanthellae symbiont or decapoda commensal have been determined by capillary G.C.
• 2.2. The fatty acid compositiion of each associated organism, host and symbiont or commensal, presents enough characteristic differences to think that each of them synthesizes de novo its own fatty acids.
• 3.3. These results suggest to us that the fatty acid composition of Palythoa and of Zooxanthellae might be a better and more useful tool for the taxonomic classification of these two families than sterol composition.

     

The influence of stigmasterol concentration on the growth and lipid composition of wild-type and barium a strains of Paramecium tetraurelia

• 1.1. The ciliary membrane lipid composition and electrophysiology of the behavioral mutant of Paramecium tetraurelia, barium A (d4–592), were previously shown to differ from those of wild-type 51S when both strains were grown in low sterol medium.
• 2.2. In this study, the phospholipid fatty acid composition of the two strains was shown to differ regardless of the level of sterol supplementation or culture age (growth phase).
• 3.3. The ratio of linoleic to γ-linolenic acid, 18:2(9,12)/18:3(6,9,12), was consistently higher in baA compared to wild-type phospholipids, largely because of a dramatic shift in the ratio of these two fatty acids esterified at the 2 position of 1-alkyl-2-acyl-sn-glycero-3-phosphorylcholine (GPC).
• 4.4. These data support the hypothesis that a specific Δ6 fatty-acyl desaturase, which directly desaturates phospholipid and shows a preference for GPC as its substrate, is impaired as a result of the barium A mutation.