bluuebunny/crossref_metadata_2025_split huggingface dataset:
2‐Hydroxy fatty acids from marine sponges 2. The phospholipid fatty acids of the caribbean spongesVerongula gigantea andAplysina archeri
Authors: Carballeira Nestor M. , Shalabi Fathi , Negron Vilmary 
Published: November 2006

AbstractThe α‐hydroxy fatty acids 2‐hydroxy‐eicosanoic (1) acid, 2‐hydroxyheneicosanoic (2) acid, 2‐hydroxydocosanoic (3) acid, 2‐hydroxytetracosanoic (4) acid, 2‐hydroxy‐23‐methyl‐tetracosanoic acid and 2‐hydroxypentacosanoic (5) acid were isolated from the Caribbean spongesVerongula gigantea andAplysina archeri. The very long chain fatty acids 5,9‐nonacosadienoic acid (29∶2) and 5,9,23‐tricontatrienoic acid (30∶3) were also identified together with theiso‐prenoid fatty acid 3,7,11,15‐tetramethylhexadecanoic (phytanic) acid that seems to be common in the Aplysinidae.A. archeri contained an extremely long chain fatty acid tentatively characterized as dotricontaenoic (32∶1) acid. These acids were found to occur in phosphatidylserine, phosphatidylinositol, phosphatidylethanolamine, phosphatidylcholine and traces of phosphatidylglycerol.
Effect of dietary fat on individual long‐chain fatty acyl‐CoA esters in rat liver and skeletal muscle
Authors: Ney Denise M. , Lasekan John B. , Spennetta Terry , Grahn Mike , Shrago Earl 
Published: November 2006

AbstractThe effect of dietary fat on the long‐chain acyl‐CoA ester profile of liver and skeletal muscle was investigated by feeding weanling rats 12%‐fat diets composed of high‐linoleic safflower oil (73% 18∶2n−6), high‐oleic safflower oil (70% 18∶1n−9) or olive oil (70% 18∶1n−9) for six and ten weeks. Approximately 50% of both hepatic and skeletal muscle acyl‐CoA esters comprised linoleoyl‐CoA or oleoyl‐CoA with high‐linoleic or oleic feeding, respectively. Total hepatic acyl‐CoA ester concentration was 40% higher (p<0.05) in rats fed 12% fat compared with controls fed a 4%‐fat diet. These data demonstrate that the long‐chain acyl‐CoA ester profile of liver and skeletal muscle reflects the dietary fatty acid profile.
Vitamin E. Deficiency increases the synthesis of platelet‐activating factor (PAF) in rat polymorphonuclear leucocytes
Authors: Fukuzawa Kenji , Kurotori Yasuhiro , Tokumura Akira , Tsukatani Hiroaki 
Published: November 2006

AbstractVitamin E deficiency was found to stimulate FMLP (N‐formyl‐L‐methionyl‐L‐leucyl‐L‐phenylalanine)‐induced biosynthesis of PAF (1‐O‐alkyl‐2‐acetyl‐sn‐glycero‐3‐phosphocholine) in polymorphonuclear leucocytes (PMN) from rat peritoneum. In three separate experiments each, the amounts of PAF synthesized during 6min and 12 min incubation of PMN cells from control, vitamin E‐supplemented, and vitamin E‐deficient rats were 129–240, 131–227 and 248–354 pmol/106 cells, respectively. The activity of the acetyl‐transferase, which transfers the acetyl moiety of [3H]acetyl‐CoA to 2‐lysoPAF (1‐O‐alkyl‐sn‐glycero‐3‐phosphocholine) to form [3H]PAF, was higher in PMN homogenates from vitamin E‐deficient rats (2.28±0.07 nmol/min/mg protein) than in those from E‐supplemented rats (1.06±0.10 nmol/min/mg protein). However, there was no difference between the two groups in the activity of acetylhydrolase (4.26±0.71 and 4.26±0.06 nmol/min/mg protein, respectively), measured as degradation of [3H]PAF to [3H]lysoPAF.In vitro addition of α‐tocopherol did not inhibit the increased activity of acetyl‐transferase in vitamin E‐deficient rats, in‐dicating that the enzyme in vitamin E‐supplemented rats was not directly inhibited by α‐tocopherol. The acetyltransferases of the two groups showed similar Km values for acetyl‐CoA, but different Vmax values (225 μM and 6.4 nmol/min/mg protein in vitamin E‐deficient rats, and 216 μM and 3.6 nmol/min/mg protein in vitamin E‐supplemented rats), suggesting that the enzyme was not activated but increased in amount in vitamin E deficiency.
The effect of enhanced intake of linoleic acid on the fatty acid composition of tissue polar lipids of post‐smolt atlantic salmon (Salmo salar)
Authors: Bell J. Gordon , Youngson Arthur , Mitchell Alexander I. , Cowey Colin B. 
Published: November 2006

AbstractDuplicate groups of Atlantic salmon (Salmo salar) post smolts were given diets in which the lipid component was either fish oil or a mixture of corn oil and lard. This difference in the dietary lipid did not significantly affect growth over a period of sixteen weeks.Proportions of docosahexaenoic acid [22∶6(n−3)] and total (n−3) fatty acids in the polar lipids of liver and white muscle were unaffected by this difference in dietary lipid component over the time period used. Fish given the diet containing corn oil and lard had significantly higher levels of 20∶2(n−6), 20∶3(n−6) and 20∶4(n−6) in the polar lipids of these tissues than were present in the tissues of the fish given diets containing fish oil. There results suggest that linoleic acid [18∶2(n−6)] undergoes elongation and desaturation to arachidonic acid [20∶4(n−6)] in post‐smolt Atlantic salmon.
Microsomal Δ5 desaturation of eicosa‐8,11,14‐trienoic acid is activated by a cytosolic fraction
Authors: Leikin Alicia L. , Brenner Rodolfo R. 
Published: November 2006

AbstractΔ5 Desaturation of eicosa‐8,11,14‐trienoic acid to arachidonic acid was studied in rat liver microsomes. It was shown that Δ5 desaturation of fatty acids in vitro requires the participation of a peripheral component of cytosolic origin. Desaturation of 20∶3n−6 to 20∶4n−6 decreases in washed microsomes as they lose an adsorbed cytosolic fraction (CF), but the enzymatic activity can be recovered as a function of CF concentration in the incubation medium. Albumin does not substitute for CF. Δ5 Desaturation of 20∶3n−6 is inhibited by arachidonic acid by a product inhibition effect, but CF prevents retroinhibition of Δ5‐desaturase by 20∶4n−6. This ability of CF is eliminated by preincubation of CF with 20∶4n−6, but not with γ−18∶3n−6, the product of Δ6 desaturation of 18∶2n−6, thus indicating that CF impairs the retroinhibitory effect of arachidonic acid on Δ5‐desaturase in a specific manner. Δ6 Desaturation of linoleic acid to γ−18∶3n−6 is also activated by CF and retroinhibited by γ−18∶3n−6. CF activity on Δ6 desaturation is retained after preincubation with 20∶4n−6, but it is lost after preincubation with γ−18∶3n−6. Activation of Δ6‐desaturase by CF is associated with the removal of the reaction product in a specific manner. Chromatography of CF by Sephacryl S‐200 separates two major subfractions which show different efficiency in reactivating Δ5‐ and Δ6‐desaturase activities in washed microsomes. Therefore, CF may contain subfractions that can prevent Δ5‐ and δ6‐desaturase retroinhibition by apparently binding their respective reaction products specifically.
Cholesterol metabolism in frog (Rana esculenta) liver: Seasonal and sex‐related variations
Authors: Bruscalupi G. , Castellano F. , Scapin S. , Trentalance A. 
Published: November 2006

AbstractMany aspects of lipid metabolism have been studied in amphibians, but seasonal lipid modulation in male and female frogs has not been investigated. We describe here the yearlong patterns of hepatic lipid content and enzyme activities related to cholesterol homeostasis, 3‐hydroxy‐3‐methylglutaryl coenzyme A (HMG‐CoA) reductase activity and acyl coenzyme A:cholesterol acyltransferase (ACAT) activity in liver of the male and female frog,Rana esculenta. Lipid storage follows distinct seasonal patterns, with an increase in June that is more pronounced in the female than in the male frog. Cholesterol content and cholesterol storage as cholesteryl ester in male liver are consistent with the activity of HMG‐CoA reductase and of ACAT enzymes. HMG‐CoA reductase activity of the female frog shows an extra peak in fall unrelated to cholesterol storage and probably related to the production of essential compound for oogenesis.
Analysis of seed oils containing cyclopentenyl fatty acids by combined chromatographic procedures
Authors: Christie William W. , Brechany Elizabeth Y. , Shukla Vijai K. S. 
Published: November 2006

AbstractThe fatty acids of seed oils of the Flacourtiaceae,Hydnocarpus anthelmintica, Caloncoba echinata andTaraktogenus kurzii, have been examined by a combination of capillary gas chromatography, silver ion high performance liquid chromatography and gas chromatography‐mass spectrometry. In addition to the common range of cyclopentenyl fatty acids found in such oils, 13‐cyclopent‐2‐enyltridec‐4‐enoic acid was a major component ofH. anthelmintica and was identified by mass spectrometry as its picolinyl ester and dimethyldisulphide adduct. It has not previously been found in nature. In the other seed oils, the isolated double bond in the corresponding fatty acid was in position 6, as expected. Similarly,cis‐4‐hexadecenoic acid and C16 and C18 cyclopentyl fatty acids were identified for the first time inH. anthelmintica. Iso‐ andanteiso‐methylbranched fatty acids were present in trace amounts.
Capillary gas chromatography and tandem mass spectrometry of paf‐acether and analogs: Absence of 1‐O‐alkyl‐2‐propionyl‐sn‐glycero‐3‐phosphocholine in human polymorphonuclear neutrophils
Authors: Bossant M. J. , Farinotti R. , De Maack F. , Mahuzier G. , Benveniste J. , Ninio E. 
Published: November 2006

AbstractFast atom bombardment‐tandem mass spectrometry was used to identify molecular species of paf‐acether (paf) produced by human polymorphonuclear neutrophils. Using this biological material, normal phase high performance liquid chromatography was necessary prior to the fast atom bombardment‐tandem mass spectrometry step. Gas liquid chromatography/electron capture detection after hydrolysis with phospholipase C and conversion to heptafluorobutyrate derivatives was used to confirm the results. The results indicated the presence of mainly 1‐O‐hexadecyl/octadecyl‐2‐acetyl‐sn‐glycero‐3‐phosphocholine, acyl analogs of paf and only trace amounts of other alkyl analogs of paf. We did not detect the 2‐propionyl analog of paf. Moreover, supplementation of human polymorphonuclear neutrophils with sodium propionate did not result in formation of the 2‐propionyl analog of paf.
Thiobarbituric acid‐reactive malondialdehyde formation during superoxide‐dependent, iron‐catalyzed lipid peroxidation: Influence of peroxidation conditions
Authors: Janero David R. , Burghardt Barbara 
Published: November 2006

AbstractA systematic study of the influence of biological lipid peroxidation conditions on lipid hydroperoxide decomposition to thiobarbituric acid‐reactive malondialdehyde is presented. A superoxide‐dependent, iron‐catalyzed peroxidation system was employed with xanthine oxidase plus hypoxanthine plus ferric iron‐adenosine diphosphate complex as free radical generator. Purified cardiac membrane phospholipid (as liposomes) was the peroxidative target, and 15‐hydroperoxy‐eicosatetraenoic acid was used as a standard lipid hydroperoxide. Exposure of myocardial phospholipid to free radical generator at physiological pH (7.4) and temperature (37°C) was found to support not only phospholipid peroxidation, but also rapid lipid hydroperoxide breakdown and consequent malondialdehyde formation during peroxidation. Under lipid peroxidation conditions, oxidative injury to the phospholipid polyunsaturated fatty acids required superoxide radical and ferric iron‐adenosine diphosphate complex, whereas 37°C temperature and trace iron were sufficient for lipid hydroperoxide decomposition to malondialdehyde. Harsh thiobarbituric acid‐test conditions following peroxidation were not mandatory for either lipid hydroperoxide breakdown or thiobarbituric acid‐reactive malondialdehyde formation. However, hydroperoxide decomposition that had begun in the peroxidation reaction could be completed during a subsequent thiobarbituric acid test in which no lipid autoxidation took place. Iron was more critical than heat in promoting the observed hydroperoxide decomposition to malondialdehyde during the lipid peroxidation reaction at 37°C and pH 7.4. These data demonstrate that the radical generator, at physiological pH and temperature, serves a dual role as both initiator of membrane phospholipid peroxidation and promotor of lipid peroxide breakdown and thiobarbituric acid‐reactive malondialdehyde formation. Consequently, peroxidation reaction conditions can directly influence lipid hydroperoxide decomposition, malondialdehyde production and system thiobarbituric acid‐reactivity. In vivo, decomposition of lipid peroxides to malondialdehyde during radical‐mediated, metal‐catalyzed membrane peroxidation may represent an integral component of oxidative tissue injury rather than a mere consequence of hydrolyzing the peroxidized biological sample in a thiobarbituric acid test.
Alpha‐ and gamma‐tocopherol levels in lipoproteins fractionated by affinity chromatography
Authors: Clevidence Beverly A. , Lehmann Joanna 
Published: November 2006

AbstractAlpha‐ and gamma‐tocopherol levels of nine women were measured in whole serum and in serum lipoproteins separated by heparin affinity chromatography. Alphatocopherol levels (mean±SD) in whole serum, low density plus very low density lipoproteins and high density lipoproteins were 10.8±2.7, 6.4±1.6 and 4.6±1.4 (μg/ml), respectively. Corresponding values (μg/ml) for gamma‐tocopherol were 1.2±0.5, 0.7±0.3 and 0.6±0.2. Recoveries of serum alpha‐ and gamma‐tocopherol from the heparin columns were 102±5% and 105±7%, respectively. Serum alpha‐tocopherol was linearly correlated with components of high density lipoprotein (apolipoproteins, high density lipoprotein cholesterol), but not with serum total lipids or indices of low density lipoprotein, even though high density lipoprotein carried less than half of the serum alpha‐tocopherol. However, serum gamma‐tocopherol was highly correlated with indices of serum lipids, such as serum cholesterol (r=0.92, p=0.005). The coefficient for the correlation of low density lipoprotein (+very low density lipoprotein) tocopherol with high density lipoprotein tocopherol was r=0.66 (p=0.06) for alpha‐tocopherol and r=0.84 (p=0.004) for gamma‐tocopherol. These differences in the relationships of the two tocopherols to lipids and lipoproteins support the view that when the two tocopherols are present at normal dietary levels, gamma‐tocopherol partitions between lipoproteins based on their relative lipid content, but a portion of the alpha‐tocopherol in high density lipoprotein is specifically bound.
Fatty acid pattern of tissue phospholipids in copper and iron deficiencies
Authors: Johnson Susan B. , Kramer Tim R. , Briske‐Anderson Mary , Holman Ralph T. 
Published: November 2006

AbstractBecause copper and iron have been reported to be essential cofactors in Δ9 desaturation of fatty acids, the effects of different dietary intakes of copper and iron on tissue fatty acids were studied. Male Long‐Evans rats (ten per group) were fed diets containing adequate, deficient or excess copper or iron. On day 42 of the dietary regimen, the animals were killed and tissues and blood were removed for analysis of metals and fatty acids of phospholipids. Compared with the copper‐adequate rats, the copper‐deficient rats showed increased 18∶0 in liver and decreased 16∶1ω7 in liver, heart and serum. There were no differences for 16∶0 or 18∶1ω9. Intake of excess copper did not cause an increase in products of Δ9 desaturation. Comparisons between iron‐deficient and iron‐adequate rats showed that iron deficiency increased 18∶2ω6 in liver and serum and decreased 20∶4ω6 in serum only. Relative percentages of 16∶0, 18∶0, 16∶1ω7 and 18∶1ω9 in liver and serum phospholipids were similar for both groups. Intake of excess iron caused a decrease in 18∶2ω6; and 16∶0 and 18∶1ω9 were higher in the liver of the iron‐excess group than the iron‐deficient group. This study did not support the requirement for copper or iron in the Δ9 desaturation of fatty acids as expressed in phospholipids of liver, heart and serum.
Eskimo plasma constituents, dihomo‐γ‐linolenic acid, eicosapentaenoic acid and docosahexaenoic acid inhibit the release of atherogenic mitogens
Authors: Smith Donald L. , Willis Anthony L. , Nguyen Ngoc , Conner Debra , Zahedi Shaye , Fulks Judy 
Published: November 2006

AbstractStudies in man and laboratory animals suggest that ω3 polyunsaturated fatty acid consituents of fish oils have antiatherosclerotic properties. We have studied the effects of several such polyunsaturated fatty acids for ability to modify the in vitro release of mitogens from human platelets. Such mitogens may produce the fibroproliferative component of atherosclerotic plaques. Both 5,8,11,14,17‐eicosapentaenoic acid (20∶5ω3) and 4,7,10,13,‐16,19‐docosahexaenoic acid (22∶6ω3), major constituents of fish oils, inhibited adenosine diphosphate‐induced aggregation of platelets and the accompanying release of mitogens. These effects are dose dependent. Linolenic acid (18∶3ω3), the biosynthetic precursor of eicosapentaenoic acid, also inhibited platelet aggregation and mitogen release. Eicosapentaenoic acid also inhibited mitogen release from human monocyte‐derived macrophages, which, in vivo, are an additional source of mitogens during atherogenesis.Potent inhibition of human platelet aggregation and mitogen release was also seen with dihomo‐γ‐linolenic acid (8,11,14‐eicosatrienoic acid 20∶3ω6), whose levels are reportedly elevated in Eskimos subsisting on marine diets.We conclude that diets that elevate plasma and/or tissue levels of eicosapentaenoic acid, docosahexaenoic acid and dihomo‐γ‐linolenic acid precursor γ‐linolenic acid (18∶3ω6) may exert antiatherosclerotic effects by inhibiting the release of mitogens from platelets and other cells.
Simple high performance liquid chromatography methods for monitoring lipase reactions
Authors: Ergan Françoise , André Gérald 
Published: November 2006

AbstractThis paper describes three simple high performance liquid chromatography methods to separate mixtures of free fatty acids, mixtures of different triglycerides and mixtures of all fat classes (monoglycerides, diglycerides, triglycerides and free fatty acids). It is possible with our methods to identify and quantify each peak of the chromatogram. These methods have been designed to monitor lipase reactions. Using a first set of conditions, we have been able to separate five fatty acids: linolenic, linoleic, palmitic, oleic and stearic, without any specific preparation of the samples. With a second set of conditions, we showed that the same mobile phase and the same column could separate both triglyceride species and fat classes. However, in the latter case, a flow gradient was used.
On the isolation of 2‐hydroxydocosanoic and 2‐hydroxytricosanoic acids from the marine spongeAmphimedon compressa
Authors: Carballeira Néstor M. , Lopez Mario R. 
Published: November 2006

AbstractThe first α‐hydroxy fatty acids from a marine sponge, namely 2‐hydroxydocosanoic and 2‐hydroxytricosanoic, were identified in the Caribbean spongeAmphimedon compressa. These acids were found to occur in phosphatidylethanolamine and phosphatidylserine and constituted 52% of the total fatty acid mixture of this sponge. The long chain fatty acids 5,9,23‐nonacosatrienoic (29∶3) and 5,9,23‐tricontatrienoic (30∶3), as well as a new tetratricontatetraenoic (34∶4) acid, were also found inA. compressa.
Long chain fatty acid deficits in brain myelin sphingolipids of undernourished rat pups
Authors: Yeh Yu‐Yan 
Published: November 2006

AbstractA restricted maternal dietary intake (40% of ad libitum intake) is known to cause myelin deficit that is accompanied by decreased amounts of individual phospholipids and sphingolipids in brain myelin of suckling rats. This communication reports the effects of the same nutritional stress on the fatty acid composition of brain myelin lipids. In myelin of 19‐day‐old normally fed rats, palmitate (16∶0), stearate (18∶0) and oleate (18∶1) accounted for 80–90% of all fatty acids in phosphatidylcholine, phosphatidylethanolamine and phosphatidylserine. Maternal dietary restriction resulted in deficits of total fatty acid content, but did not affect the proportional distribution of individual fatty acids among phospholipids. By contrast, longer chain (22‐ and 24‐carbon) fatty acids accounted for more than half the fatty acid content of myelin cerebroside and sulfatide from the 19‐day‐old control rat pups. In undernourished rats of that age, proportions of lignocerate (24∶0) and nervonate (24∶1) in cerebroside and sulfatide were 40–50% lower than those in control rats. This, together with higher proportions of 16∶0, 18∶0 and 18∶1 and a higher ratio of C16−C20 to C22−C24 in under‐nourished than in control rats, suggests an impairment in fatty acid chain elongation. Ten days of nutritional rehabilitation failed to restore the fatty acid imbalances; however, after an additional 5 days of ad libitum feeding, the experimental and control values were similar. The undernutrition results in hypomyelination, which is characterized by a proportional decrease in lignoceric and nervonic acids of sphingolipids.
A novel bioaction of PAF: Induction of microbicidal activity in guinea pig bone marrow cells
Authors: Hayashi Hidetoshi , Kudo Ichiro , Kato Toshiyuki , Nozawa Ryushi , Nojima Shoshichi , Inoue Keizo 
Published: November 2006

AbstractWhen guinea pig bone marrow cells were incubated in the presence of 10−8 to 10−6 M platelet activating factor (PAF) for 24 to 72 hr, microbicidal activity againstCandida parapsilosis of cells was augmented. This augmentation was inhibited by PAF‐specific antagonists, CV6209 or FR900452. PAF‐specific binding sites with a high affinity were found on guinea pig bone marrow cells. Carrageenan or 2‐chloroadenosine, reagents known to be preferentially cytotoxic to macrophages, abolished the microbicidal activity of PAF‐treated bone marrow cells. Macrophages prepared from the peritoneal cavity, however, acquired no appreciable microbicidal action by treatment with PAF. These observations suggest that PAF may affect a class of guinea pig bone marrow cells through binding to receptors specific to PAF, resulting in activation and/or induction of differentiation of monocyte‐macrophage lineage cells.
Erythrocyte contamination of leukocyte populations following density‐gradient centrifugation results in artificially high levels of human leukocyte HMG‐CoA reductase activity
Authors: Harwood H. James , Bridge Donna M. , Stacpoole Peter W. 
Published: November 2006

AbstractWhen measuring human leukocyte HMG‐CoA reductase activity, special care must be taken to prevent erythrocyte contamination of the leukocyte layer during isopycnic centrifugation. Contamination during leukocyte isolation and subsequent erythrocyte lysis during NH4Cl treatment results in increased leukocyte microsomal HMG‐CoA reductase activity. Increased enzyme activity is not due to enzyme dephosphorylation, thiol‐disulfide reduction or increased enzyme protein concentration. Leukocyte populations containing granulocytes appear to be most sensitive. Prevention of erythrocyte contamination during isopycnic centrifugation should aid in accurate measurement of human leukocyte HMG‐CoA reductase activity.
Novel method to administer radiolabeled lipid to juvenile oysters
Authors: Erickson Marilyn C. , Selivonchick Daniel P. 
Published: November 2006

AbstractParticles prepared from egg yolk were shown to encapsulate protein and to be in a size range that would be filtered by the oyster. A radiotracer study involving the addition of radiolabeled phosphatidylcholine to egg yolk demonstrated that the egg yolk particles were taken up and metabolized by juvenile oysters (Crassostrea gigas). Catabolism of the radiolabeled lipid and subsequent resynthesis into non‐lipid components occurred to a slight extent. The main factor responsible for the distribution of radioactivity amongst the lipids in the stomach tissue was believed to be transacylation.