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.

     

Fermentation and the production of volatile fatty acids in the alimentary tract of the rock hyrax,Procavia capensis

• 1.1. Aspects of ruminant-like metabolism were examined in the hyrax Procavia capensis.
• 2.2. High concentrations of volatile fatty acids occurred in the cardiac stomach with a predominance of acetic and lactic acids.
• 3.3. Acetic (69%), propionic (22%) and butyric (8%) acids occurred in highest concentrations in the proximal caecum, with appreciable amounts in the proximal colon, distal caecum and appendices.
• 4.4. The depot fat contained high proportions of unsaturated C₁₈ (linoleic and linolenic) acids.
• 5.5. The glucose level in the plasma was within the range established for non-ruminant herbivores.
• 6.6. The possibility of silage-like fermentation occurring in the cardiac stomach is discussed.

     

Serum lipoproteins of sea bass (Dicentrarchus Labrax L.). Purification and partial characterization by density gradient ultracentrifugation and agarose column chromatography

• 1.1. Five classes of sea bass serum lipoproteins were purified by single vertical spin ultracentrifugation and agarose column chromatography
• 2.2. VLDL, beta migrating, are the larger and less dense lipoproteins.
• 3.3. LDL are the more heterogeneous in size, ranging from 11 × 10⁶ to 1 × 10⁶.
• 4.4. HDL represent the predominant class which, on the basis of density and electrophoresis migration, is differentiated in three subclasses.
• 5.5. VHDL float at a density > 1.22 mg/ml, which corresponds to the density of the other serum lipoproteins. This subclass, with an apparent molecular weight of 1.5 × 10⁵, resembles the albumin-like fatty acids binding proteins, shown in mammals and teleosts and absent in elasmobranchs.

     

Organ specific changes in energy metabolism due to anaerobiosis in the sea mussel Mytilus edulis (L.)

• 1.1. Anaerobic energy metabolism was investigated in different organs of Mytilus edulis and the whole animal.
• 2.2. Succinate accumulates to high levels in most organs but remains low in the hemolymph.
• 3.3. After 16 hours propionate accumulation is observed in all organs. Experimental evidence is not sufficient yet to point out organs that produce more propionate than others.
• 4.4. Acetate is a minor end product.
• 5.5. Acetate and propionate are found in the hemolymph in amounts equal to those in the organs.
• 6.6. Animals incubated in oxygen-free seawater accumulate more end products than animals exposed to air, in the form of volatile fatty acids that are excreted into the incubation water.
• 7.7. Alanine and glutamine increase in the posterior adductor muscle. Aspartate decreases in the total animal, posterior adductor muscle and gills, while in the hemolymph decrease in alanine, asparagine, serine, threonine and proline are observed.

     

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.

     

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.

     

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.

     

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.

     

Lipid changes in blood serum and tissues of the Egyptian Cobra “Naja haje haje” during the hibernation cycle

• 1.Total lipids, free fatty acids, triglycerides, phospholipids and total cholesterol in blood serum, liver, brain, cardiac and skeletal muscles of Naja haje haje were determined during the different phases of the hibernation cycle.
• 2.A sharp decrease in the level of total lipids of blood serum and all tissues occurred during hibernation. Upon arousal, lipogenesis is commonly restored.
• 3.Elevated concentrations of serum free fatty acids predominated in pre-hibernation and hibernation periods, while the tissues recorded highly significant declines during hibernation.
• 4.Occurrence of marked decreases in triglycerides contents of serum and tissues except the cardiac muscles in the hibernation and arousal phases.
• 5.Sharp increases in the phospholipid contents of blood and the selected tissues were recorded during hibernation. The level declined in both liver and cardiac muscles in arousing animals.
• 6.Total cholesterol level was lowered in blood during hibernation. The cardiac muscles showed a highly significant decrease while liver, brain and skeletal muscles showed elevations in the same phase.

     

Changes in the concentration of some minor constituents of milk from cows fed low- or high-fat diets

• 1.1. The concentration of isocitrate and 2-oxoglutarate in cows' milk was determined in cows fed low- or high-fat diets.
• 2.2. The concentration of 2-oxoglutarate in milk correlated positively with the short and medium chain fatty acids in milk fat.
• 3.3. The concentration of isocitrate in milk correlated negatively with the short and medium chain fatty acids in milk fat.
• 4.4. It is proposed that changes in the concentrations of these minor constituents of milk occur as a result of changes in their intracellular concentrations. In the present experiment these changes are probably the result of changes in the rate of fatty acid synthesis de novo in the mammary gland.

     

Respiratory function and nucleotide composition of erythrocytes from tropical elasmobranchs

• 1.1. Oxygen carrying capacity and parameters of erythrocyte-oxygen binding are similar for a range of elasmobranchs with markedly different swimming behaviour.
• 2.2. Erythrocyte nucleotide components in sharks include the allosteric hemoglobin modifiers GTP and ATP in similar ratios, and the total pool appears independent of locomotory activity. A rhinobatoid ray had no detectable erythrocyte trinucleotides, but had an appreciable pool of AMP together with IMP.
• 3.3. There was no evidence for either urea or NaCl modulation of hemoglobin function in erythrocytes from a carcharhinid shark.
• 4.4. These observations lead to the conclusion that parameters of the oxygen transport system in elasmobranchs are highly conserved.

     

Changes in the phospholipid composition and in fatty acids of phosphatidylcholine and phosphatidylethanolamine of various tissues of the developing tadpole of Agalychnis dacnicolor

• 1.1. Lipid changes occur in the developing tadpole of A. dacnicolor. The phosphatidylcholine content of liver and tail decrease during metamorphosis.
• 2.2. In liver, the fatty acids of phosphatidylcholine and phosphatidylethanolamine become more unsaturated.
• 3.3. In skin, phosphatidylcholine becomes more unsaturated and phosphatidylethanolamine becomes more saturated.
• 4.4. In tail, phosphatidylcholine becomes more saturated and phosphatidylethanolamine shows no change.
• 5.5. Triglycerides become more unsaturated in skin but become more saturated in tail.

     

Effect of different levels of dietary fats upon the positional distribution of fatty acids in rat body triacylglycerols

• 1.1. The main purpose of the study was to describe and to compare the effect of different dietary fatty acids introduced at different levels into the diet on the positional distribution of fatty acids in rat body triacylglycerols. Only distribution between sn-2 (internal) and sn-1 + sn-3 (external) positions was considered in this study.
• 2.2. The positional distribution of fatty acids was first determined for controls fed on a low fat diet (1% D.M.). The same study was then carried out with 11 different dietary treatments and results were systematically compared with controls. The effects of four main molecules were tested: linoleic acid, oleic acid, lauric acid and capric acid.
• 3.3. Different alterations of the positional distribution of fatty acids in body triacylglycerols were obtained. They are graphically described and discussed.

     

Specific dynamic action (SDA) in the supralittoral isopod,Ligia pallasii: Identification of components of apparent SDA and effects of dietary amino acid quality and content on SDA

• 1.1. Specific Dynamic Action (SDA) effects of diet were investigated in the supralittoral isopod, Ligia pallasii, using defined chemical diets.
• 2.2. “Apparent SDA”, or the total rise in metabolic rate following a meal, was resolved in animals eating a nutritionally complete chemical diet into three components: 8% mechanical costs of moving food through the gut, 40% “excitement costs” due to investigator disturbance and presence of food, and 52% SDA.
• 3.3. Excitement costs in animals exposed to food but which chose not to eat showed non-significant variation between diets containing different levels of chemical nutrients, but were significantly less on a diet containing only cellulose and agar.
• 4.4. SDA increased with increasing concentration of amino acids in the diet.
• 5.5. Substitution of whole-protein casein for free amino acids in the diet had no significant SDA effect, while substitution of free amino acids in the ratio found in casein more than doubled the SDA effect.
• 6.6. Deletion of alanine from the diet caused no significant effect on SDA, while deletion of phenylalanine caused a highly significant elevation in SDA.

     

The effects of oxalate and glucose on lipogenesis by isolated hepatocytes from normal and biotin-deficient chicks (Gallus domesticus)

• 1.1. Isolated hepatocytes synthesize fatty acids and cholesterol from lactate and acetate with lactate being the more effective substrate.
• 2.2. Biotin deficiency decreased fatty add synthesis from both substrates but stimulated cholesterogenesis.
• 3.3. Exposure of intact hepatocytes to oxalate inhibited fatty acid and cholesterol synthesis from lactate, this effect was enhanced in biotin-deficient chicks. A similar effect was not observed when acetate was the substrate.
• 4.4. Synthesis of fatty acids from lactate and acetate was stimulated by glucose, biotin deficiency increased this response. Cholesterogenesis was reduced in control but not biotin-deficient chicks.

     

Haematology of the australian eastern quoll,Dasyurus viverrinus

• 1.1. A variety of haematological parameters were determined in adult Dasyurus viverrinus.
• 2.2. Haemoglobin and red cell counts were high with a very low mean cell volume.
• 3.3. Basophils are absent but the eosinophils contain small numbers of basophilic granules which may indicate a dual role for this cell.
• 4.4. “Ring Form” leucocytes are present.
• 5.5. Three types of red cell picture could be identified, some animals showing large numbers of spherocytes, spicule cells, and inclusion bodies.
• 6.6. These cells resemble those found in some inherited human haemolytic anaemias but there was no evidence of haemolysis in the animals.
• 7.7. An alkali resistant haemoglobin component is present.

     

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.

     

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.

     

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.

     

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.