Influence of dietary sources of fat on lipid synthesis in mink (Mustela vison) mammary tissue

• 1.1. The fatty acid composition of the triglyceride fraction of mink milk sampled during mid-lactation (day 28 post partum) from two nursing mink was compared to that of plasma samples and to the fatty acid composition of the feed rations used.
• 2.2. Chemical analysis of the triglyceride composition of mink milk demonstrated only minute concentrations of fatty acids with a chain length below C₁₄.
• 3.3. The saturated C_16:0- and C_18:0-unit fatty acids in mink milk made up for 24–40% of the total amount of fatty acids extracted, the remainder being represented by mono and polyunsaturated long-chain (C₁₆-C₂₄) fatty acids.
• 4.4. Preliminary in vitro experiments proved the incorporation of¹⁴C-labelled glucose, acetate or palmitate into triacylglycerols in cultures of mink mammary tissue to be linear for at least 2 hr.
• 5.5. The in vitro capacity for de novo fatty acid synthesis in mink mammary tissue using 14C-labelled glucose or acetate was low, i.e. ranging from 0.096–0.109 nmol/g (fresh tissue)/min, and amounted to only about 5% of that obtained in the case of [¹⁴C]palmitic acid incubation.
• 6.6. Following ¹⁴C-labeIled acetic or palmitic acid incubation of mink mammary tissue neither desaturation nor chain elongation was observed.
• 7.7. In response to long-term feeding on rations with two different sources of animal fat (F = fish oil or L = lard) the influence of compositional changes in dietary neutral lipids on the fatty acid composition of the lipids of mink milk is discussed.

     

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.

     

Comparative study of the endemic freshwater fauna of lake baikal—I. Phospholipid and fatty acid composition of two mollusc species,Baicalia oviformus and Benedictia baicalensis

• 1.1. Lipid and phospholipid compositions of endemic freshwater molluscs belonging to the class Gastropoda, Baicalia oviformus and Benedictia baicalensis, were studied.
• 2.2. The fatty acids composition of total lipids, neutral, glyco- and phospholipid fraction was investigated by capillary gas chromatography-mass spectrometry.
• 3.3. Ninety-five fatty acids were identified: 23 saturated (both iso- and anteiso-), 28 monoenoic, 14 dienoic and 30 polyenoic.
• 4.4. High percentage of the two main acids, 18:4 and 18:4(n-3) in phospholipid and glycolipid fractions were identified.
• 5.5. A number of unusual polyunsaturated fatty acids, such as 19:4, 18:5(n-3), 24:4(n-6), 24:5(n-6), 24:6(n-3), and furanoid acids, were found.

     

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.

     

Differential effects of fatty acid chain length on the viability of two species of cactophilic Drosophila

• 1.1. Two columnar cacti in the Sonoran Desert, agria and organpipe, contain medium chain (C₈−C₁₂) fatty acids.
• 2.2. Necrotic tissues of these cacti serve as feeding and breeding substrates for Drosophila mojavensis but not D. nigrospiracula.
• 3.3. Results show that capric and lauric acids are the predominant fatty acids of both cacti.
• 4.4. Fatty acid chain length exhibits a differential effect on larval viability with caprylic acid (Q) having the greatest and myristic acid (C₁₄) having the least effect.
• 5.5. Drosophila mojavensis is more tolerant of free fatty acids than D. nigrospiracula, and this partly explains the ability of D. mojavensis to utilize agria and organpipe cacti.

     

Lipid composition of Calanus finmarchicus from the north sea and the arctic. A comparative study

• 1.1. Females, copepodid stages V and IV of Calanus finmarchicus were collected in Fram Strait area of the Arctic and in the northern North Sea to compare their lipid composition.
• 2.2. For the comparison only copepods were considered which contained more than 8% of 18:4 fatty acid and high amounts of wax esters to exclude seasonal and spatial variabilities and different reproductive status of females.
• 3.3. Animals are heavier in the Fram Strait area than in the North Sea with similar lipid proportion of dry weight and wax ester proportion of total lipid.
• 4.4. Only some statistical significant differences exist between the fatty acid and alcohol compositions. The levels of 16:0 acid and alcohol and of 22:1 alcohol are higher and of 20:1 acid and alcohol are lower in the North Sea than in the Arctic.

     

Significant year-to-year variation of the response to radiation-induced stress shown by gill fatty acid metabolism in eels (Anguilla anguilla captured from the wild

• 1.1. In eels captured in Roskilde Fjord in 1972 and 1975, a specifically enhanced synthesis was found from ¹⁴C-acetate of ¹⁴C-labelled mono-unsaturated fatty acids (C_16:1 and C_18:1) relative to saturated fatty acids (C_16:0 and C_18:0) in sea water 4 days after irradiation (10 Gy, ⁶⁰Co).
• 2.2. Corresponding experiments in 1976 and 1982 showed rather the opposite: irradiation resulted in more ¹⁴C-labelled saturated fatty acids relative to unsaturated fatty acids, both in fresh and sea water.
• 3.3. The latter effect was less marked than that in 1972 and 1975, but still statistically clearly significant.

     

Palmitic acid metabolism in hepatopancreas of the freshwater shrimp Macrobrachium borellii

• 1.1. The palmitic acid fate as substrate for the synthesis of either glycerides or other fatty acids was studied in vivo and in the microsomal fraction from hepatopancreas of Macrobrachium borellii.
• 2.2. Most of the palmitic acid administered in vivo circulated to the hepatopancreas, being incorporated mainly in the triacylglycerol (TG) fraction.
• 3.3. Palmitic acid transformations into palmitoleic, stearic and oleic acids were observed in the hepatopancreas.
• 4.4. The in vitro biosynthesis of TG in hepatopancreas was more active than in other tissues. In the microsomal fraction, palmitic acid was also incorporated mainly in TG, and followed the α-glycerophosphate pathway.

     

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.

     

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.

     

Volatile fatty acid excretion during anaerobiosis in the lugworm Arenicola marina

• 1.1. Accumulation and excretion of propionate and acetate during experimental anaerobiosis were investigated in the lugworm Arenicola marina.
• 2.2. The rate of accumulation and the ratio propionate/acetate were found to be tissue-specific.
• 3.3. The excretion of the volatile fatty acids showed a characteristic time course.
• 4.4. The results of experiments analyzing the role of different organs indicate that the excretion of these metabolites proceeded via the undifferentiated surface of the body.
• 5.5. The rate of excretion depended on the concentration gradient between animal and the ambient water, the chain-length of the fatty acid and the pH of the water. Propionate excretion was inhibited by butyrate.

     

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.

     

Cotranslational fatty acylation of mucus glycoprotein. Addition of palmitic acid to peptidyl-tRNA occurs prior to peptide chain completion and its release

• 1.1. The fatty acylation of mucus glycoprotein nascent peptides was investigated using [³H]palmitic acid and [³⁵S]methionine-labeled peptidyl-tRNA of rat gastric mucous cells.
• 2.2. The mucus glycoprotein peptidyl-tRNA fraction was found to contain covalently bound palmitic acid in its complexes.
• 3.3. RNase digestion of the mucus glycoprotein peptidyl-tRNA released [³H]palmitic acid labeled peptides which, on SDS-polyacrylamide gel, separated into a multitude of bands ranging in size from 2000 to 60,000 Da.
• 4.4. The analyses of low molecular weight peptides revealed that palmitic acid was present in methionine-labeled peptides containing 30–43 amino acids and those of 18–25 amino acids or larger devoid of methionine, but was not identified in methionine-labeled peptides containing 10–15 amino acids.
• 5.5. The results indicate that the N-terminal fatty acylation of mucus glycoprotein nascent peptides is a cotranslational process which is occuring in an immediate vicinity of the signal peptide fragment.

     

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.

     

Lipid components and utilization in consumers of a seagrass community: An indication of carbon source

• 1.1. The lipid components of three animals, the rock crab Nectocarcinus integrifons, the rock flathead Platycephalus laevigatus and the southern garfish Hyporhamphus melanochir, feeding in the seagrass beds at Corner Inlet, Victoria, Australia have been examined in detail in order to provide further information on seagrass community structure.
• 2.2. Biological marker compounds detected within animal gut content material were used to recognize dietary sources and then utilized by community members.
• 3.3. Both H. melanochir and N. integrifons have been shown to ingest and to varying degrees incorporate seagrass lipid material, thus further confirming the importance of seagrass carbon in the Corner Inlet environment.
• 4.4. The southern sea garfish H. melanochir is observed to remove C₁₈ PUFAs (polyunsaturated fatty acids) from ingested seagrass material.
• 5.5. Seagrass sterols are altered during incorporation into the lipids of this fish.
• 6.6. Lipid-rich digestive juices play a role in the digestive processes of all three animals.
• 7.7. Components tentatively identified as (NMI) (non-methylene interrupted) fatty acids have been detected in the lipids of the garfish H. melanochir and the crab N. integrifons.
• 8.8. The fecal material of all three animals represent possible sources of these lipids (NMI acids) in Corner Inlet sediments.
• 9.9. Based on lipid compositional data, N. integrifons feeds on Posidonia australis detritus and associated epiphyte material.
• 10.10. The removal of both plant and epibiota cellular lipids along the digestive tract of the crab was observed, although structural components such as long chain mono- and α,ω-dicarboxylic acids, which have been previously recognized as seagrass marker lipids are not directly absorbed.

     

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.

     

The influence of calcium and magnesium on sea bass (Dicentrarchus labrax) intestinal brush border membrane purification and activity

• 1.1. The activity of brush border enzymes (alkaline phosphatase, maltase, sucrase, trehalase, leucine amino peptidase) was higher in purified membranes prepared with calcium. The contamination of these membranes with basolateral membranes was also lower (1.27 for Na-K-ATPase activity ratio).
• 2.2. The extraction of brush border lipids was carried out according to Folch adapted method. Two dimensional thin layer chromatography was used to separate the phospholipidic fractions. Fatty acids of phospholipids were analysed using gas chromatography after acid transmethylation (column SP 2330).
• 3.3. Phospholipids are composed of phosphatidylcholine (PC: 33%), phosphatidylethanolamine (PE: 30%), sphingomyeline (SM: 21%), phosphatidylserine (PS: 14%) and phosphatidylinositol (PI: 2%). 4. PC, PE and PS are characterized by high levels of unsaturated fatty acids (monounsaturated MUFA: 21.5% and polyunsaturated PUFA: 34.9%). The most abundant PUFA belong to the (n-3) family [18:3 (n-3), 20:5 (n-3) and 22:6 (n-3)].
• 4.5. Fatty acids from sphingomyelin of purified membranes have low proportions of PUFA (13.5%) but higher proportions of MUFA (39.5%).
• 5.6. No specific differences were found between calcium and magnesium prepared membranes.
• 6.7. The low content in LPC and the absence of LPE confirmed the absence of major structural lipids transformation during the membrane purification with calcium or magnesium.
• 7.8. Glycine transport was measured during 10 sec at different temperatures using the rapid filtration technique. Glycine transport was higher with Na⁺ than with K⁺. In the presence of Na⁺, this transport increases with temperature.
• 8.9. Arrhenius curves were mono phasic without obvious breakpoint and indicated no phase transition in the lipid bilayer.
• 9.10. A significant Na⁺ dependent glycine transport has been characterized at low temperatures (0°C) which suggests a possible role of membrane polyunsaturated fatty acids in the control of glycine transport.

     

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.

     

Effects of milk fat,unhydrogenated and partially hydrogenated vegetable oils on serum lipoproteins in growing pigs

• 1.1. Crossbred Yorkshire (Yorkshire × Landrace) pigs were fed butter oil, cream, low erucic acid rapeseed oil, sunflower oil and partially hydrogenated sunflower oil in amounts representing 30% of energy for periods of up to 13 weeks.
• 2.2. After 13 wk of feeding serum total cholesterol levels of pigs fed milk fat were significantly higher than of pigs fed vegetable oils.
• 3.3. The difference in cholesterol was mainly due to an increase in the density range of 1.063–1.125 g/ml containing pig LDL₂ and some HDL.
• 4.4. A shift towards smaller LDL particle size was apparent in pigs fed milk fat.
• 5.5. The effects of dietary trans fatty acids did not differ from cis polyunsaturated or monounsaturated fatty acids.