bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of dietary lipid on polyunsaturated fatty acid metabolism in Atlantic salmon (Salmo salar) undergoing parr‐smolt transformation
Authors: Bell J. Gordon , Tocher Douglas R. , Farndale Bruce M. , Cox David I. , McKinney Richard W. , Sargent John R. 
Published: November 2006

AbstractThe aim of this study was to measure the changes in lipid metabolism which occur during smoltification and seawater transfer in Atlantic salmon (Salmo salar). Duplicate groups of Atlantic salmon parr were fed diets containing either fish oil (FO) or a blend of linseed and rapeseed oils, vegetable oil (VO), from October (week 0) to seawater transfer in May (week 26). From May to August (weeks 26–43), all fish were fed a fish oil‐containing diet. Fatty acyl desaturation and elongation activity were followed in isolated hepatocytes incubated with radioactive 18:3n−3 and 18:2n−6. Metabolism of 18:3n−3 was consistently around 5‐fold greater than metabolism of 18:2n−6, and total metabolism of both substrate polyunsaturated fatty acids (PUFA) was increased in fish fed both VO and FO up to seawater transfer after which desaturation activities were reduced. Desaturation activities with both 18:3n−3 and 18:2n−6 were significantly greater in fish fed VO, compared to fish fed FO, at 22 and 26 wk. Arachidonic acid (20:4n−6; AA) in liver polar lipids (PL) of fish fed VO increased consistently from weeks 0–22 but varied after seawater transfer. In fish fed FO, AA in liver PL remained constant up to week 17 before increasing at seawater transfer and leveling off thereafter. Eicosapentaenoic acid (20:5n−3; EPA) in liver PL of fish fed VO decreased significantly from week 0–22 before rising at seawater transfer and increasing rapidly posttransfer. EPA in liver PL of fish fed FO showed a similar trend except EPA was always greater in the freshwater phase compared to fish fed VO. Docosahexaenoic acid (DHA) levels in liver PL of fish fed VO remained constant in the freshwater phase before increasing following seawater transfer. In fish fed FO, DHA in liver PL increased from weeks 0–17 reducing and leveling off postseawater transfer. The levels of PGF2α and PGF3α were measured in isolated gill cells stimulated with calcium ionophore A23187. PGF2α production in fish fed VO increased significantly between 0–7 wk before decreasing toward seawater transfer. After transfer, PGF2α production increased to a peak at 35 wk. PGF2α production in fish fed FO was not significantly altered during the trial period. The changes in PGF3α production were broadly similar to those occurring with PGF2α, but the latter was always in excess of the former (2‐to 4‐fold). Plasma chloride concentrations in fish subjected to seawater challenge at 20 wk were significantly lower in fish fed VO compared to those fed FO. This study has provided new information on the changes in lipid metabolism which accompany parr‐smolt transformation and suggests that diets which have a fatty acid composition more similar to that in aquatic invertebrates may be beneficial in effecting successful seawater adaptation.
Modifying the n−3 fatty acid content of the maternal diet to determine the requirements of the fetal and suckling rat
Authors: Guesnet Philippe , Alasnier Corinne , Alessandri Jean‐Marc , Durand Georges 
Published: November 2006

AbstractDuring perinatal development, docosahexaenoic acid (22:6n−3) accumulates extensively in membrane phospholipids of the nervous system. To evaluate the n−3 fatty acid requirements of fetal and suckling rats, we investigated the accumulation of 22:6n−3 in the brain and liver of pup rats from birth to day 14 postpartum when their dams received increasing amounts of dietary 18:3n−3 (from 5 to 800 mg/100 g diet) during the pregnancy‐lactation period. The fatty acid composition of brain and liver phospholipids of pups, as well as that of dam's milk, was determined. At birth, brain 22:6n−3 increased regularly to reach the highest level when the maternal diet contained 800 mg 18:3n−3/100 g. On days 7 and 14 postpartum, brain 22:6n−3 plateaued at a maternal dietary supply of 200 mg/100 g. Docosapentaenoic acid (22:5n−6) had the opposite temporal pattern. The unusually high concentration of eicosapentaenoic acid (20:5n−3) in liver and dam's milk observed at the highest 18:3n−3 intake suggests an excessive dietary supply of this fatty acid. All these data suggest that the n−3 fatty acid requirements of the pregnant rat are around 400 mg 18:3n−3 and those of the lactating rat at 200 mg (i.e., 0.9 and 0.45% of dietary energy, respectively). The values for 18:3n−3 and 22:6n−3 milk content which allowed brain 22:6n−3 to reach a plateau value in suckling pups were 1% of total fatty acids and 0.9% (colostrum) to 0.2% (mature milk), respectively. These levels are similar to those recommended for infant formulas.
Nonionic surfactants. Regioselective synthesis of fatty acid esters of α‐ and β‐glucopyranose
Authors: De Luca Damiano , De Nino Antonio , Liguori Angelo , Procopio Antonio , Sindona Giovanni 
Published: November 2006

AbstractLipophilic esters of saccharides belong to the family of nonionic surfactants widely employed in pharmaceutical and cosmetics formulations. A very simple method is presented whereby 6‐O‐esters of α‐ and β‐glucose can be prepared and isolated. Good results have been obtained in the synthesis of 6‐O‐oleyl derivatives by simple acylation with appropriate oleyl chloride. The condensing agent bis(2‐oxo‐3‐oxazolidinyl) phosphinic chloride (BOP‐Cl) allows the preparations of the same esters with better regioselectivity but with yields strongly dependent on the aliphatic chain length of the carboxylic acids employed.
Novel fatty acid esters of (7E, 12E, 18R, 20Z)‐variabilin from the marine sponge Ircinia felix
Authors: Martínez Alejandro , Duque Carmenza , Fujimoto Yoshinori 
Published: November 2006

AbstractThe methanolic extract of the marine sponge Ircinia felix has yielded nine novel fatty acid esters, (7E, 12E, 18R, 20Z)‐variabilin (5Z, 9Z)‐22‐methyltricosadienoate, (7E, 12E, 18R, 20Z)‐variabilin (5Z, 9Z)‐tetracosadienoate, (7E, 12E, 18R, 20Z)‐variabilin hexadecanoate, (7E, 12E, 18R, 20Z)‐variabilin 10‐methylhexadecanoate, (7E, 12E, 18R, 20Z)‐variabilin 15‐methylhexadecanoate, (7E, 12E, 18R, 20Z)‐variabilin 14‐methylhexadecanoate, (7E, 12E, 18R, 20Z)‐variabilin 9‐octadecenoate, (7E, 12E, 18R, 20Z)‐variabilin octadecanoate, and (7E, 12E, 18R, 20Z)‐variabilin 2,11‐dimethyloctadecanoate, along with the recently described (7E, 12E, 18R, 20Z)‐variabilin 11‐methyloctadecanoate. The characterization of the new fatty acids (5Z, 9Z)‐22‐methyltricosadienoic and 2,11‐dimethyloctadecanoic acids is also described. The chemical structures were determined by extensive spectroscopic, chromatographic, and chemical analyses.
Low fat‐monounsaturated rich diets containing high‐oleic peanuts improve serum lipoprotein profiles
Authors: O’Byrne Dawn J. , Knauft David A. , Shireman Rachel B. 
Published: November 2006

AbstractPostmenopausal hypercholesterolemic women are at risk for cardiovascular disease and are encouraged to follow low‐fat (LF) (≤30% energy) diets. However, these diets may have undesirable effects on high density lipoprotein cholesterol (HDL‐C), apolipoprotein A‐I (apo A‐I) and triglycerides, whereas diets high in monounsaturated fats do not. Twenty postmenopausal hypercholesterolemic women previously consuming high‐fat diets (34% energy) were placed on a low fat‐monounsaturated rich diet (LFMR: 26%, 14% energy, respectively) for 6 mon. Sixteen women already eating LF diets (24% energy) were also followed to monitor variations in serum lipids due to seasonal variations. Twenty‐five women successfully completed the study (LFMR=12, LF=13). Serum cholesterol decreased 10% (264 to 238 mg/dL, P≤0.01) and low density lipoprotein cholesterol (LDL‐C) decreased 12% (182 to 161 mg/dL, P≤0.01) in the LFMR group, but did not change in the LF group. The reduction in serum cholesterol in the LFMR group was greater than estimated by predictive formulas. Serum triglycerides and apo A‐I did not change in the LFMR group. A modest decrease in HDL‐C, HDL3‐C, and apolipoprotein B (apo B) occurred in both groups, but only the LFMR group showed a trend toward beneficial changes in LDL‐C/HDL‐C and apo A‐I/apo B ratios. Overall, the LFMR diet was well tolerated and resulted in an improved serum lipid and apolipoprotein profile.
Incorporation of n‐3 fatty acids into plasma lipid fractions, and erythrocyte membranes and platelets during dietary supplementation with fish, fish oil, and docosahexaenoic acid‐rich oil among healthy young men
Authors: Vidgren Helvi M. , Ågren Jyrki J. , Schwab Ursula , Rissanen Tiina , Hänninen Osmo , Uusitupa Matti I. J. 
Published: November 2006

AbstractThe effects of n‐3 fatty acid supplementation in the form of fresh fish, fish oil, and docosahexaenoic acid (DHA) oil on the fatty acid composition of plasma lipid fractions, and platelets and erythrocyte membranes of young healthy male students were examined. Altogether 59 subjects (aged 19–32 yr, body mass index 16.8–31.3 kg/m2) were randomized into the following diet groups: (i) control group; (ii) fish diet group eating fish meals five times per week [0.38±0.04 g eicosapentaenoic acid (EPA) and 0.67±0.09 g DHA per day]; (iii) DHA oil group taking algae‐derived DHA oil capsules (1.68 g/d DHA oil group taking algae‐derived DHA oil capsules (1.68 g/d DHA in triglyceride form); and (iv) fish oil group (1.33 g EPA and 0.95 g DHA/d as free fatty acids) for 14 wk. The fatty acid composition of plasma lipids, platelets, and erythrocyte membranes was analyzed by gas chromatography. The subjects kept 4‐d food records four times during the study to estimate the intake of nutrients. In the fish diet, in DHA oil, and in fish oil groups, the amounts of n‐3 fatty acids increased and those of n‐6 fatty acids decreased significantly in plasma lipid fractions and in platelets and erythrocyte membranes. A positive relationship was shown between the total n‐3 polyunsaturated fatty acids (PUFA) and EPA and DHA intake and the increase in total n‐3 PUFA and EPA and DHA in all lipid fractions analyzed. DHA was preferentially incorporated into phospholipid (PL) and triglyceride (TG) and there was very little uptake in cholesterol ester (CE), while EPA was preferentially incorporated into PL and CE. The proportion of EPA in plasma lipids and platelets and erythrocyte membranes increased also by DHA supplementation, and the proportion of linoleic acid increased in platelets and erythrocyte membranes in the DHA oil group as well. These results suggest retroconversion of DHA to EPA and that DHA also interferes with linoleic acid metabolism.
Conversion of 18∶3 Δ9cis, 12cis, 15trans in rat liver microsomes
Authors: Chardigny Jean‐Michel , Blond Jean‐Paul , Bretillon Lionel , Mager Estelle , Poullain Didier , Martine Lucy , Vatèle Jean‐Michel , Noël Jean‐Pierre , Sébédio Jean‐Louis 
Published: November 2006

AbstractSeveral years ago, it was established that the Δ15 trans isomer of α‐linolenic acid is converted in vivo into fatty acids containing 20 and 22 carbons (geometrical isomers of eicosapentaenoic and docosahexaenoic acids). The present study focused on the in vitro Δ6 desaturation, the first step of the biosynthesis of the n‐3 long‐chain polyunsaturated fatty acids from 18:3n‐3. For that purpose, rat liver microsomes were prepared and incubated with radiolabeled 18∶3 Δ9cis, 12cis, 15cis (18∶3 c,c,c) or 18∶3 Δ9cis, 12cis, 15trans (18∶3c,c,t) under desaturation conditions. The data show that 18∶3c,c,t is converted at a lower rate compared with α‐linolenic acid. The product of conversion of 18∶3 c,c,t may be 18∶4 Δ6cis, 9cis, 12cis, 15trans resulting from a Δ6 desaturation of the trans substrate. Moreover, the conversion of radiolabeled 18∶3c,c,t was strongly decreased by the presence of 18∶3c,c,c (up to 48%) while the 18∶3c,c,t only slightly decreased the conversion of radiolabeled 18∶3c,c,c. Thus, the desaturation enzyme presented a higher affinity for the native all‐cis n‐3 substrate.
Increased hepatic β‐oxidation of docosahexaenoic acid, elongation of eicosapentaenoic acid, and acylation of lysophosphatidate in rats fed a docosahexaenoic acid‐enriched diet
Authors: Kanazawa Ayako , Shirota Yuri , Fujimoto Kenshiro 
Published: November 2006

AbstractRats were fed a diet supplemented with corn oil (n‐3 deficient), soy oil, or a mixture containing 8% 22∶6n‐3 ethyl ester for 6 wk. The hepatic capacities for the β‐oxidation and synthesis of 22∶6n‐3, in addition to the acylation of lysophosphatidate, were tested in vitro. In rats that were fed a 22∶6n‐3‐enriched diet, both the β‐oxidation of 22∶6n‐3 and elongation of 20∶5n‐3 were enhanced compared to those in rats fed the other diets. Acylation of lysophosphatidate was also enhanced in rats fed a 22∶6n‐3‐enriched diet, while the rate of dephosphorylation of phosphatidate was not changed. The amount of 22∶6n‐3 in the liver was much less than that consumed in a docosahexaenoic acid‐enriched diet. These results suggest that a significant amount of dietary 22∶6n‐3 was degraded via β‐oxidation, and that a portion of the retroconverted 20∶5n‐3 was recycled for the synthesis of 22∶6n‐3. The recycling of 20∶5n‐3 might contribute to the low level of 22∶6n‐3 in rats fed an n‐3‐deficient diet.
Oral acetylsalicylic acid induces biliary cholesterol secretion in the rat
Authors: Prigge William F. , Gebhard Roger L. 
Published: November 2006

AbstractSeveral agents can alter biliary cholesterol secretion, critical for cholesterol excretion and gallstone formation. Although salicylate effects on bile formation and gallstones have been studied, biliary lipid secretion has not been measured during oral aspirin treatment. We examined whether oral acetylsalicylic acid affects bile lipid secretion. Three groups of young rats were fed chow for 3 wk. Two of the groups then received aspirin at either 1.67 or 3.33 g/kg diet for 4 d. Serum, hepatic, and bile lipids were measured, as were enzymes of cholesterol synthesis and esterification. With oral aspirin, bile cholesterol secretion increased by 42% and hepatic cholesteryl ester content decreased by 40%. Serum cholesterol and hepatic free cholesterol did not change. To evaluate mechanisms of the cholesterol hypersecretion, hypothyroid animals fed low‐fat or fish oil diets and repleted with triiodothyronine were also studied. Aspirin stimulated cholesterol secretion to a degree similar to triiodothyronine. An additive response was seen in fish oilfed rats. Aspirin did not appear to have a primary action on 3‐hydroxy‐3‐methylglutaryl‐CoA reductase or acyl CoA:cholesterol acyltransferase activities, and had no direct effect on esterification of cholesterol by isolated hepatocytes. Aspirin may directly increase cholesterol transport into bile or have cell membrane effects which alter cholesterol transport. It remains to be determined whether the observed alterations in bile cholesterol secretion are specific to the rat or also apply to humans.
An improved synthesis of taurine‐ and glycine‐conjugated bile acids
Authors: Momose Toshiaki , Tsubaki Takayuki , Iida Takashi , Nambara Toshio 
Published: November 2006

AbstractA simple and efficient method for the synthesis of taurine‐ and glycine‐conjugated bile acids is described. The condensation reaction was achieved by the simple mixing of unconjugated bile acid (1.0 eq.), taurine (2.0 eq.) (or glycinate ester), diethyl phosphorocyanidate (1.2 eq.) in the presence of triethylamine at room temperature for 30–60 min. Sample clean‐up was effected by the use of a prepacked Sep‐Pak C18 cartridge for reversed‐phase solid extraction or by direct recrystallization, yielding the desired taurine and glycine conjugates in 89–93 and 92–96% isolated yields, respectively.
A synthesis of 4‐hydroxy‐2‐trans‐nonenal and 4‐(3H) 4‐hydroxy‐2‐trans‐nonenal
Authors: Chandra Animesh , Srivastava Satish K. 
Published: November 2006

Abstract4‐Hydroxy‐2‐trans‐nonenal, the most abundant and toxic unsaturated aldehyde generated during membrane lipid peroxidation, was synthesized starting from fumaraldehyde dimethyl acetal. In the first step of the synthesis, the fumaraldehyde dimethyl acetal was partially hydrolyzed using amberlyst catalyst to obtain the monoacetal. The 4‐hydroxy‐2‐trans‐nonenal was synthesized by the Grignard reaction of the fumaraldehyde monoacetal with 1‐bromopentane. 4‐Hydroxy‐2‐trans‐nonenal, obtained as its dimethylacetal, was oxidized to its corresponding 4‐keto derivative using pyridinium chlorochromate buffered with sodium acetate as the oxidizing agent. 4‐(3H) 4‐Hydroxy‐2‐trans‐nonenal was obtained in one step by the sodium borotriteride reduction of the 4‐keto derivative.
Chromogenic assay for phospholipase D from Streptomyces chromofuscus: Application to the evaluation of substrate analogs
Authors: Hergenrother Paul J. , Haas Michelle K. , Martin Stephen F. 
Published: November 2006

AbstractA rapid and convenient chromogenic assay for phospholipase D from Streptomyces chromofuscus (PLDSc) has been developed that converts the choline generated from the enzyme‐catalyzed hydrolysis of phospholipids into a chromogenic dye. By quenching the reaction with EDTA at defined times, an initial rate curve is produced from which a kcat and Km can be readily derived. This assay has been applied to the biological evaluation of several substrate analogs, all of which appear to be activators rather than substrates or inhibitors of this enzyme. Performing the assay in 96‐well microtiter plates allows for the easy screening of potential effectors of this enzyme.
Recombinant antibody fragments that detect enoyl acyl carrier protein reductase in Brassica napus
Authors: Ziegler Angelika , Macintosh Sybil M. , Torrance Lesley , Simon William , Slabas Antony R. 
Published: November 2006

AbstractPurified Brassica napus enoyl acyl carrier protein reductase (ENR) was used to select specific antibodies from a library of antibody fragments, single‐chain Fv (scFv), displayed on filamentous phage. Analysis of the selected clones by BstNl fingerprinting and nucleotide sequencing showed that the scFv were derived from three different human VH germline genes. The binding specificities were confirmed by Western blots and ELISA. The scFv preparations reacted with B. napus ENR, but not with β‐keto reductase, nor enoyl reductase from Escherichia coli. Analysis of fragments generated by CNBr treatment indicates that the scFv 3.13 recognizes an epitope located within the n‐terminal 80 amino acids of the enzyme molecule. The scFv were used to detect ENR directly in extracts of B. napus seeds.
Use of cyclodextrin to deliver lipids and to modulate apolipoprotein B‐100 production in HepG2 cells
Authors: Peluso Michael R. , Dixon Joseph L. 
Published: November 2006

Abstract2‐Hydroxypropyl‐β‐cyclodextrin (cyclodextrin), cyclodextrin‐solubilized oleate, and cyclodextrin‐solubilized cholesterol were used to modulate proteolysis and secretion of newly‐synthesized apolipoprotein B‐100 (apoB) in HepG2 cells. Following cyclodextrin and lipid treatments, cells were pulse‐labeled with [3H] leucine, and quantitative immunoprecipitation was used to measure apoB synthesis, apoB secreted into the medium, and the cellular content of undegraded apoB that was not secreted. Three‐hour treatment with cyclodextrin‐solubilized oleate (0.2 mM) increased secreted apoB from 4% (control cells) to 32% and cellular undegraded apoB from 15% (control cells) to 64% of apoB synthesized, which is consistent with earlier studies using bovine serum albumin to complex exogenous oleate. Prolonged daily (4 d or more) administration of 0.5% (3.5 mM) cyclodextrin with medium containing 10% fetal bovine serum increased the secretion of nascent apoB from 5–10% (control) to 17–28% and cellular undegraded apoB from 15–20% (control) to 25–31% of apoB synthesized, respectively. Subsequent administration of cyclodextrin‐solubilized cholesterol (10–40 μg) for only 3 h reversed the cyclodextrin‐mediated increase in apoB secretion. The application of 0.5% cyclodextrin to HepG2 cells can rapidly (within minutes) stimulate cholesterol efflux, and transiently (over a 1–2 d period) increase cholesterol synthesis. In the current studies, the cyclodextrin‐mediated increase in cholesterol synthesis was not concurrent with the increase in apoB secretion. However, prolonged (15 d) administration of cyclodextrin was shown to increase the cellular free cholesterol concentration by 25–41%, reduce the cellular triglyceride concentration by 59% and increase apoB secretion 3‐ to 4‐fold, without affecting the cellular cholesteryl ester concentration. In comparison, 14‐d treatment with cyclodextrin‐solubilized cholesterol (20 μg/mL) followed by 1‐d equilibration without cholesterol was shown to increase the cellular free cholesterol and cholesteryl ester concentrations by 76% and 10‐fold, respectively, although apoB secretion was not affected. It is hypothesized that chronic daily administration of 0.5% cyclodextrin increased the cellular cholesterol concentration and flux in discrete putative regulatory compartment which “shielded” nascent apoB from rapid proteolysis and facilitated apoB secretion. In conclusion, cyclodextrin was used independently and in combination with cholesterol or oleate to modulate apoB proteolysis and secretion. We speculate that subcellular changes in cholesterol concentration and flux may modulate apoB production in HepG2 cells.
Characterization of polar and nonpolar seed lipid classes from highly saturated fatty acid sunflower mutants
Authors: Álvarez‐Ortega Rosario , Cantisán Sara , Martínez‐Force Enrique , Garcés Rafael 
Published: November 2006

AbstractThe seed lipids from five sunflower mutants, two with high palmitic acid contents, one of them in high oleic background, and three with high stearic acid contents, have been characterized. All lipid classes of these mutant seeds have increased saturated fatty acid content although triacylglycerols had the highest levels. The increase in saturated fatty acids was mainly at the expense of oleic acid while linoleic acid levels remained unchanged. No difference between mutants and standard sunflower lines used as controls was found in minor fatty acids: linolenic, arachidic, and behenic. In the high‐palmitic mutants palmitoleic acid (16∶1n−7) and some palmitolinoleic acid (16∶2n−7, 16∶2n−4) also appeared. Phosphatidylinositol, the lipid with the highest palmitic acid content in controls, also had the highest content of palmitic or stearic acids, depending on the mutant type, suggesting that saturated fatty acids are needed for its physiological function. Positional analysis showed that mutant oils have very low content of saturated fatty acids in the sn‐2 position of triacylglycerols, between the content of olive oil and cocoa butter.
Lipids and ultrastructure of Thraustochytrium sp. ATCC 26185
Authors: Weete J. D. , Kim H. , Gandhi S. R. , Wang Y. , Dute R. 
Published: November 2006

AbstractAs a representative of a genus with species considered to be potential commercial producers of the nutritionally important polyunsaturated fatty acid docosahexaenoic acid (DHA), Thraustochytrium sp. ATCC 26185 was investigated to determine its potential for DHA production and lipid composition. Cells from liquid shake cultures contained 32% (w/w) lipid, 18% of which was nonsaponifiable lipid. The major saturated fatty acids (14∶0 and 16∶0) comprised up to 59% of the total fatty acids, and DHA was up to 25% after 6 d incubation. Squalene represented 63% of the nonsaponifiable lipid, and cholesterol composed 41% of the total sterols. The phospholipids expected for eucaryotic microbes were detected with phosphatidylcholine as the major phospholipid at 76% of the total. The ultrastructure of this species was similar to other Thraustochytrium species except that the cells did not have surface scales and they contained unusual membrane‐like structures that appeared to be associated with oil formation.