Fatty acid composition of depot fats,and rumen wall of the camel (Camelus dromedarius

• 1.1. Fatty acid composition of depot fats (hump, subcutaneous, mesentry, abdomen, perinephric and peticardiac) and rumen wall of Camelus dromedarius were studied by gas-liquid chromatography.
• 2.2. All depot fats showed similar characteristics; major fatty acids found were palmitic, stearic, oleic and myristic. Small quantities of odd-numbered, palmitoleic, linoleic and linolenic acids were also present.
• 3.3. Fatty acid of rumen wall showed some differences from the general pattern.
• 4.4. Fatty acid composition of the camel is discussed in relation to that of other ruminants and monogastrics.

     

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.

     

Cortical and medullary lipids of normal and nephrosclerotic human kidney

• 1.1. Major lipid classes from cortical and medullary zones of normal and nephrosclerotic human kidneys have been isolated and the fatty acid composition of each determined.
• 2.2. The nephrosclerotic tissue contained two times more total lipid than the normal kidney but, irrespective of kidney pathology, phospholipids were the major cortical lipids and neutral lipids were the predominant lipids in medullary zones.
• 3.3. Human kidney contained large amounts of phosphatidylcholines, phosphatidylethanolamines and sphingomyelins and although these were slightly increased in the sclerotic kidney, anatomical differences in phospholipid content were not significant.
• 4.4. Quantitative differences between the zones of normal kidney were found with triglycerides, diglycerides. free fatty acids and cholesterol; overall, the sclerotic tissue contained more triglycerides and small amounts of cholesterol esters with less significant regional differences.
• 5.5. Palmitic, oleic and stearic acid were the major fatty acids of neutral lipids; these plus linoleic acid were prevalent in phospholipids.

     

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.

     

A further contribution to the knowledge of the blood lipid fractions from the african elephant Loxodonta africana

• 1.1. Plasma lipids from 5 African elephants were extracted and fractionated into cholesterol esters, free fatty acids, triglycerides, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, sphingomyelin and glycosphingolipids. The fatty acids of various individual fractions were investigated by gas-chromatography.
• 2.2. All animals, except one, had a high linoleic acid content in cholesterol esters indicating an adequate supply of linoleic acid in the diet.
• 3.3. Phosphatidyl choline had a strong saturated character originating from the presence of unusually high quantities of stearic acid.
• 4.4. Phosphatidylethanolamine was present in small quantities and was characterized by a low content of arachidonic acid.
• 5.5. Sphingomyelin did not contain any long chain saturated acids. Instead it contained 10.2–47.0% of a long chain acid which was most likely monounsaturated.
• 6.6. The presence of significant quantities of glycosphingolipids was established.

     

Spingophosphonolipids in microsomes of Diplodon delodontus. Distribution and effect on the membrane microviscosity

• 1.1. The distribution of ceramide aminoethylphosphonate (CAEP) in microsomal membranes obtained from different tissues of the bivalve mollusc Diplodon delodontus was determined.
• 2.2. The concentration of CAEP reached from 9 to 19% of the total microsomal polar lipids, depending on the kind of tissue.
• 3.3. Palmitic acid was the main fatty acid in the ceramide moiety, followed by stearic and eicosamonoenoic acids.
• 4.4. Artificial membranes were prepared with microsomal phospholipids or phospholipids plus sterols, with and without the addition of CAEP.
• 5.5. It was shown that the phosphonate confers minor mobility to the membranes. This effect is more effective when the membrane contains the natural sterols and the phospholipids are unsaturated.

     

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.

     

Isotopic labeling of taurine; implications for its synthesis in selected tissues of Homarus americanus

• 1.1. The abdominal muscle and ventral nerve chord of Homarus americanus were incubated with radioactive precursors.
• 2.2. ³⁵SO₄ and ¹⁴C-CO₂ were not incorporated into amino acids in the abdominal muscle.
• 3.3. ¹⁴C-glucose was incorporated into serine, cysteine, cysteine-sulfinic acid and taurine in the abdominal muscle.
• 4.4. ¹⁴C-CO₂ appeared to be slightly incorporated into taurine in the ventral nerve chord.
• 5.5. ¹⁴C-glucose incubation with the ventral nerve chord resulted in labeling of the same amino acids as in the abdominal muscle.
• 6.6. The results are discussed in view of the catabolism of carbohydrates and the synthesis of taurine.

     

Supply of polyenoic fatty acids to the mammalian brain: The ease of conversion of the short-chain essential fatty acids to their longer chain polyunsaturated metabolites in liver,brain, placenta and blood

The metabolism of linoleic and linolenic acids to the longer polyunsaturated fatty acids of mammalian brain is discussed. Differences in metabolic activity are considered between tissues, between species, and during different stages of development. Available evidence suggests that:

• 1.1. The sites of metabolism are confined mainly to liver and the brain itself.
• 2.2. The similar metabolic pathways are subject to a complex control which is most effective at the first step in the sequence.
• 3.3. During early development there are reciprocal changes in the metabolic capacity of brain and liver.
• 4.4. Metabolic activity varies between species and may be absent in obligate carnivores.

     

Evidence of presence of a low molecular weight,non-metallothionein-like metal-binding protein in the marine gastropod Nassarius reticulatus L.

• 1.1. A low molecular weight metal-binding protein was found in the snail Nassarius reticulatus cytosol, which was induced in heavy metal contaminated environments.
• 2.2. In our sodium dodecyl sulfate-mercaptoethanol polyacrylamide gel systems it behaved as a protein of 19 kDa mol. wt.
• 3.3. Amino acid composition studies definitely established this protein not to be metallothionein (Mt) like, because it had a much lower level of cysteine and substantial amounts of aromatic amino acids and histidine.
• 4.4. The metal-binding strength of this protein was concluded to be much weaker than that of Mt.
• 5.5. In the crustacean Pagurus bernhardus L. such a protein could not be demonstrated.
• 6.6. In both the snail and the crustacean Zn may inhibit the accumulation of Hg. The premise for studying the induction of the metal-binding Nassarius protein as a supplement to environmental metal monitoring purposes is briefly discussed.

     

The fatty acid composition of leech lipids

• 1.1. The constituent fatty acids of the neutral and phospholipids of Macrobdella ditetra, Nephelopsis obscura, Philobdella gracilis and Hirudo medicinalis have been determined.
• 2.2. Unsaturated fatty acids predominated in both neutral and phospholipid fractions of all leech species examined.
• 3.3. Arachidonic acid (20:4) was the most prevalent fatty acid in all species, accounting for as much as 36.7% of the total phospholipid fatty acids.

     

Dietary linoleic acid affects phospholipid fatty acid composition in heart and eicosanoid production by cardiomyocytes from atlantic salmon (Salmo salar)

• 1.1. Atlantic salmon post-smolts were fed practical-type diets containing linoleic acid at 10, 25 or 45% of total dietary fatty acids for a period of 20 weeks.
• 2.2. As dietary linoleic acid was increased, individual phospholipids of heart contained increased levels of 18:2n-6, 20:2n-6, 20:3n-6 and 20:4n-6 and reduced levels of 20:5n-3. The ratio of n-3/n-6 polyunsaturated fatty acids in heart phospholipids decreased and the ratio of 20:4n-6/20:5n-3 increased.
• 3.3. An increased production of thromboxane B₂ occurred in isolated cardiac myocytes from fish given the highest dietary linoleic acid but the production of 6-keto prostaglandin F_1α was not significantly affected, nor was the activity of heart sarcoplasmic reticulum Ca²⁺-Mg²⁺ ATPase (EC 3.6.1.4).

     

Phospholipids composition and metabolism in the hemolymph of Carcinus maenas (Crustacea,Decapoda)—Effect of temperature

• 1.1. The distribution of different phospholipids and the repartition of fatty acids extracted from hemolymph of crab Carcinus maenas are analysed.
• 2.2. The action of the temperature on the lipid composition is also determined: an increase of content of PE and a slight rise of the degree of unsaturation of fatty acids are found at lower temperatures.
• 3.3. The specific radioactivity of total phospholipids, phosphatidyl-choline and phosphatidylethanolamine from hemolymph of Carcinus maenas is studied from two radioactive precursors (³²Phosphorus and ³H]ethanolamine). Results suggested that the conversion of PE into PC by methylation could take place in hepatopancreas of Carcinus maenas.
• 4.4. The specific radioactivity of phospholipids from these two same radioactive compounds is increased following a variation in the environmental temperature.
• 5.5. The composition of hemolymph lipids could be a direct reflection of the lipid metabolism of the hepatopancreas and that the temperature alters the rate of the phospholipid exchange between hepatopancreas and hemolymph.
• 6.6. It is suggested that these lipid alterations occur in order to permit crab Carcinus maenas to support large changes in environmental temperatures.

     

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.

     

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.

     

Transport of cholesterol in the hemolymph of the mollusc Diplodon delodontus

• 1.1. The dietary and inter-organ cholesterol transport in the hemolymph of the bivalve mollusc Diplodon delodontus, was studied. Plasma and hemocytes were obtained after feeding labeled cholesterol to animals or injecting it into the posterior adductor muscle.
• 2.2. In both cases, cholesterol was incorporated either into plasma or hematic cells.
• 3.3. Two plasmatic fractions differing in their hydrated densities were recognized as cholesterol carriers and were isolated. They have characteristics of high density (HDL) and very high density (VHDL) lipoproteins, respectively.
• 4.4. The major lipids in the different classes of lipoproteins were free sterols in HDL and phospholipids in VHDL.
• 5.5. Neither low nor very low density lipoprotein transporting cholesterol was detected.

     

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.

     

Adaptation of fatty acid compositions to temperature—a study on planktonic crustaceans

• 1.1. Fats of freshwater crustaceans overwintering in an active form are richer in long chain polyunsaturated fatty acids (50%) than of those spending the winter in form of resting eggs (10%).
• 2.2. The former species (Cyclops vicinus, Eudiaptomus gracilis) increase the level of docosahexaenoic acid from about 10 to 25% in their phospholipids with decreasing environmental temperature.
• 3.3. Exposing warm-adapted Cyclops vicinus and Eudiaptomus gracilis to 5°C in laboratory brought about an increase in the phospholipid docosahexaenoic acid level from 10 to 24%.
• 4.4. Ability to adapt membrane fluidity to the temperature might be important for survival at low temperatures.

     

Lipids in the storage organs of three mermithid nematodes and in the hemolymph of their hosts

• 1.1. Trophosomes of the mosquito parasitic mermithid Romanomermis culicivorax and two strains of the blackfly parasitic mermithid Neomesomermis flumenalis contained in order of prevalence: triacylglycerols, phospholipids, sterols and sterol esters.
• 2.2. Triacylglycerols in the trophosomes comprised a wide array of fatty acids, sterol esters a smaller variety.
• 3.3. The degree of unsaturation of triacylglycerols and sterol esters was greater for N. flumenalis than R. culicivorax.
• 4.4. The hemolymph of the three host species (Aedes aegypti, Prosimulium mixtum/fuscum, Simlium venustum) contained an assortment of fatty acids, with a higher degree of unsaturation in the simuliids than in the culicid.
• 5.5. The overall lipid concentration of the blood of A. aegypti was unaltered by parasitism, but the mermithid caused an increase in the myristic acid:palmitic acid ratio in the free fatty acid fraction of the host's haemolymph.