bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of highly hydrogenated soybean oil and cholesterol on plasma, liver cholesterol, and fecal steroids in rats
Authors: Kamei Masaharu , Ohgaki Sumiko , Kanbe Tamotsu , Niiya Isao , Mizutani Haruo , Matsui‐Yuasa Isao , Otani Shuzo , Morita Shigeru 
Published: November 2006

AbstractWe investigated the relationship between dietary highly hydrogenated soybean oil (HSO) and cholesterol transport in rats. In the first study, to examine the effects of cholesterol transport of different concentrations of HSO in dietary oil, rats were given one of the three diets containing 0, 25, or 50% HSO in dietary oil with cholesterol (5 g/kg diet) or a diet without HSO and cholesterol for 22 d. Feeding the high concentration of HSO prevented the increase in plasma total cholesterol, hepatic total lipids, and cholesterol and the decrease in high‐density lipoprotein‐cholesterol, which were caused by dietary cholesterol. Moreover, HSO increased the fecal excretion, fecal lipids, and steroids in a dose‐dependent manner. In the second study, to examine the effects on cholesterol transport of redistribution of stearic acid in the triacylglycerol species contained in HSO, rats were given one of the six diets containing HSO (distearoylmonoacylglycerol and tristearoylglycerol)‐rich, monostearoylglycerol‐rich, or palmitic acid‐rich oil with/without cholesterol (5 g/kg diet), for 30 d. Whereas the accumulation of cholesterol in the body was reduced, cholesterol excretion was enhanced effectively in rats given the HSO‐rich diet compared with rats given the monostearoylglycerol‐rich diet. These results suggested that not only the high concentration of stearic acid but also its uneven distribution in HSO‐triacylglycerol contributed to the reduction in intestinal cholesterol absorption in rats.
Inhibition of gonadotropin‐stimulated ovarian steroid production by polyunsaturated fatty acids in teleost fish
Authors: Mercure François , Van Der Kraak Glen 
Published: November 2006

AbstractThe effects of the polyynsaturated fatty acids (PUFAs)—eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA)—onin vitro steroid production by full‐grown prematurational ovarian follicles from goldfish and rainbow trout were investigated. EPA and DHA inhibited gonadotropin‐stimulated testosterone production in a dose‐related manner, but AA was inhibitory only at the highest dose tested (400 μM). AA alone stimulated testosterone production by increasing cAMP production, but the effects of other PUFAs alone were marginal. The inhibitory actions by PUFAs were not restricted to long‐chain PUFAs, as linoleic and linolenic acids had similar actions in the goldfish. The inhibitory action of EPA on testosterone production was reversible upon removal of the PUFA from medium. Testosterone production stimulated by the addition of the cAMP analogues, dibutyryl cAMP, and 8‐bromo cAMP, was attenuated by PUFAs, suggesting that they act at a site distal to cAMP formation. A post‐cAMP site regulating cholesterol availability may be involved as testosterone production induced by addition of 25OH‐cholesterol was not affected by the PUFAs in either fish species. Together, these findings underscore the importance of lipids in ovarian physiology and suggest that PUFAs may participate in the regulation of ovarian steroidogenesis in teleost fish.
Occurrence of 22∶3n−9 and 22∶4n−9 in the lipids of the topminnow (Poeciliopsis lucida) hepatic tumor cell line, PLHC‐1
Authors: Tocher Douglas R. , Dick James R. , Sargent John R. 
Published: November 2006

AbstractThe lipids of the hepatic tumor cell line, PLHC‐1, from the topminnow (Poeciliopsis lucida), were found to contain considerable amounts of a range of n−9 polyunsaturated fatty acids despite culture in serum containing significant amounts of essential fatty acids. The structural identity of all the n−9 polyunsaturated fatty acids was confirmed by gas chromatography/mass spectrometry. Of particular interest, PLHC‐1 cell total lipid contained 1.9% of 22∶3n−9 and 3.3% of 22∶4n−9. As the culture medium contained virtually no n−9 polyunsaturated fatty acids, these fatty acids are all formed by the PLHC‐1 cells, presumably form 18∶1n−9. The 22∶3n−9 and 22∶4n−9 are presumably formed by processes of elongation and “Δ4” desaturation of Mead acid, 20∶3n−9, present at over 11% in fatty acids of total lipid. Both 22∶3n−9 and 22∶4n−9 were primarily located in phosphatidylserine (4.1 and 8.5% respectively) and, to a lesser extent, in phosphatidylethanolamine (2.2 and 6.5%, respectively), in common with the C22derivatives of the n−3 and n−6 series, whereas 20∶3n−9 was preferentially located in phosphatidylinositol (31.2%). The results establish that long‐chain polyunsaturated fatty acids of the n−9 series can be formed in vertebrate tissue other than in conditions of classical essential fatty acid deficiency.
Very long chain fatty acids in higher animals—A review
Authors: Poulos Alf 
Published: November 2006

AbstractFatty acids with greater than 22 carbon atoms (very long chain fatty acids, VLCFA) are present in small amounts in most animal tissues. Saturated and monoenoic VLCFA are major components of brain, while the polyenoic VLCFA occur in significant amounts in certain specialized animal tissues such at retina and spermatozoa. Biosynthesis of VLCFA occurs by carbon chain elongation of shorter chain fatty acid precursors while β‐oxidation takes place, almost exclusively in peroxisomes. Mitochondria are unable to oxidize VLCFA because they lack a specific VLCFA coenzyme A synthetase, the first enzyme in the β‐oxidation pathway. VLCFA accumulate in the tissues of patients with inherited abnormalities in peroxisomal assembly, and also in individuals with defects in enzymes catalyzing individual reactions along the β‐oxidation pathway. It is believed that the accumulation of VLCFA in patient tissues contributes to the severe pathological changes which are a feature of these conditions. However, little is known of the role of VLCFA in normal cellular processes, and of the molecular basis for their contribution to the disease process. The present review provides an outline of the current knowledge of VLCFA including their biosynthesis, degradation, possible function and involvement in human disease.
Trans fatty acid isomers in Canadian human milk
Authors: Chen Z. ‐Y. , Pelletier G. , Hollywood R. , Ratnayake W. M. N. 
Published: November 2006

AbstractThe fatty acid composition, totaltrans content (i.e., sum of all the fatty acids which may have one or moretrans double bonds) and geometric and positional isomer distribution of unsaturated fatty acids of 198 human milk samples collected in 1992 from nine provinces of Canada were determined using a combination of capillary gas‐liquid chromatography and silver nitrate thin‐layer chromatography. The mean totaltrans fatty acid content was 7.19±3.03% of the total milk fatty acids and ranged from 0.10 to 17.15%. Twenty‐five of the 198 samples contained more than 10% totaltrans fatty acids, and thirteen samples contained less than 4%. Totaltrans isomers of linoleic acid were 0.89% of the total milk fatty acids with 18∶2Δ9c, 13t being the most prevalent isomer, followed by 18∶2Δ9c, 12t and 18∶2Δ9t, 12c. Using the totaltrans values in human milk determined in the present study, the intake of totaltrans fatty acids from various dietary sources by Canadian lactating women was estimated to be 10.6±3.7 g/person/d, and in some individuals, the intake could be as high as 20.3 g/d. The 18∶1trans isomer distribution differed from that of cow's milk fat but was remarkably similar to that in partially hydrogenated soybean and canola oils, suggesting that partially hydrogenated vegetable oils are the major source of thesetrans fatty acids.
Thermal acclimation and dietary lipids alter the composition, but not fluidity, of trout sperm plasma membrane
Authors: Labbe C. , Maisse G. , Müller K. , Zachowski A. , Kaushik S. , Loir M. 
Published: November 2006

AbstractThe effect of a long‐term adaptation of rainbow trout to 8 and 18°C combined with a corn oil‐or a fish oil‐supplemented diet on the characteristics of the spermatozoan plasma membrane was investigated. The experiment lasted up to 22 mon during which spermatozoa were collected from the mature males. Spermatozoan plasma membranes were isolated by nitrogen cavitation, and the cholesterol content, phospholipid composition and fatty acid pattern were investigated. Membrane viscosity was assessed on whole cells by electron spin resonance using spin‐labeled phospholipids. Neither diet nor rearing temperature influenced the cholesterol content of the plasma membrane nor the phospholipid class distribution. The rearing temperature of the broodstock only slightly affected the phospholipid fatty acids. A minor decrease in 18∶0 and increase in monounsaturated fatty acids was observed for the cold‐adapted fish. These modifications were not sufficient to affect membrane fluidity, and we conclude that trout spermatozoa do not display any homeoviscous adaptations in these conditions. On the contrary, the dietary fatty acid intake greatly modified the fatty acid profile of plasma membrane phospholipids. The fish oil‐fed trout displayed a much higher n−3/n−6 fatty acid ratio than did the corn oil‐fed ones, but the 22∶6n−3 levels remained unchanged. Modifications in plasma membrane composition by the diet were obtained although neither of the two diets was deficient in essential fatty acids. The enrichment in n−3 fatty acids, however, did not affect plasma membrane fluidity which was unchanged by the diets.
ω‐3 Fatty acids in smooth muscle cell phospholipids increase membrane cholesterol efflux
Authors: Dusserre Eric , Pulcini Thérèse , Bourdillon Marie‐Claude , Ciavatti Maryvonne , Berthezene François 
Published: November 2006

AbstractThe aim of our work was to determine whether fatty acid modifications in smooth muscle cell phospholipids affect cholesterol efflux and desorption. [3H]Cholesterol was used to label cholesterol pools in the whole cell or selectively in the plasma membrane. Cells were incubated for 12 h in order to increase oleate, linoleate, arachidonate, eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) in phospholipids. Cholesterol efflux was monitored using native or tetranitromethane modified high‐density lipoprotein3 (HDL3). When all cholesterol pools were labeled, the efflux from cells treated with different fatty acids were not different. Plasma membrane cholesterol efflux remained unchanged after oleate, linoleate or arachidonate treatments, but was markedly increased after EPA and DHA enrichment, both with native HDL3 and with tetranitromethane‐high‐density lipoprotein. These results suggest that the positive effects of n−3 fatty acid consumption on the atherosclerotic process could be linked in part to an increase in plasma membrane cholesterol efflux from vascular smooth muscle cells.
Inhibition of soybean lipoxygenase‐1 by chain‐breaking antioxidants
Authors: Maccarrone Mauro , Veldink Gerrit A. , Vliegenthart Johannes F. G. , Agrò Alessandro Finazzi 
Published: November 2006

AbstractThe aim of this investigation was to determine whether chain‐breaking antioxidants able to prevent lipid peroxidation can inhibit lipoxygenase‐1 (EC 1.13.11.12). Therefore, the effects of ascorbic acid, 6‐palmitoylascorbic acid and trolox on the enzyme activity were analyzed by means of Lineweaver‐Burk double reciprocal plots and Yoshino's graphical method. The effect of these compounds on the formation of free radicals during lipoxygenase‐1 reaction was investigated as well, by monitoring the enzymic formation of oxodienes. We present evidence that the chain‐breaking antioxidants ascorbic acid, 6‐palmitoylascorbic acid and trolox inhibit soybean lipoxygenase‐1 in the micromolar concentration range (Ki 27, 3 and 18 μM, respectively). The inhibition is competitive, complete and reversible. All three compounds trap the free radicals formed during the lipoxygenase‐catalyzed reaction, which might substantially contribute to their inhibitory ability. These findings can have physiological significance in the light of the lipoxygenase involvement in biomembrane remodelling.
A microsomal membrane component associated with iron reduction in NADPH‐supported lipid peroxidation
Authors: Tampo Yoshiko , Yonaha Masanori 
Published: November 2006

AbstractThis study was conducted to determine whether a factor responsible for reduced nicotinamide adenine dinucleotide phosphate (NADPH)‐supported lipid peroxidation in rat liver microsomes is involved in iron reduction by cooperation with NADPH‐cytochrome P450 reductase. Under anaerobic conditions, NADPH‐dependent reduction of ferric pyrophosphate in microsomes was not dependent on cytochrome P450 levels and was not inhibited by carbon monoxide (CO). All of the iron complexes with chelators such as adenosine 5′‐diphosphate, pyrophosphate, nitrilotriacetate, oxalate or citrate were reduced in microsomes, although in the reconstituted system containing purified NADPH‐cytochrome P450 reductase little or no iron reduction was found. A cytochrome P450‐free fraction from a cholate‐solubilized preparation of microsomes after passage through a laurate sepharose column was required for reduction of iron pyrophosphate in the reconstituted system leading to lipid peroxidation. The iron reduction was not inhibited by CO and was destroyed by heat treatment or trypsin digestion of the fraction. All iron complexes were reduced in the presence of the fraction, using a reducing equivalent of NADPHvia NADPH‐cytochrome P450 reductase. The results indicate that a heat‐labile component, which is probably a protein distinct from cytochrome P450, is associated with iron reduction responsible for lipid peroxidation in microsomes.
Zinc deficiency and activities of lipogenic and glycolytic enzymes in liver of rats fed coconut oil or linseed oil
Authors: Eder Klaus , Kirchgessner Manfred 
Published: November 2006

AbstractIn previous studies, zinc‐deficient rats force‐fed a diet with coconut oil as the major dietary fat developed a fatty liver, whereas zinc‐deficient rats force‐fed a diet with linseed oil did not. The present study was conducted to elucidate the reason for this phenomenon. In a bifactorial experiment, rats were fed zinc‐adequate or zinc‐deficient diets containing either a mixture of coconut oil (70 g/kg) and safflower oil (10 g/kg) (“coconut oil diet”) or linseed oil (80 g/kg) (“linseed oil diet”) as a source of dietary fat, and activities of lipogenic and glycolytic enzymes in liver were determined. In order to ensure adequate food intake, all the rats were force‐fed. Zinc‐deficient rats on the coconut oil diet developed a fatty liver, characterized by elevated levels of triglycerides with saturated and monounsaturated fatty acids. These rats also had markedly elevated activities of the lipogenic enzymes acetyl‐CoA carboxylase, fatty acid synthase (FAS), glucose‐6‐phosphate dehydrogenase (G6PDH), 6‐phosphogluconate dehydrogenase (6PGDH), and citrate cleavage enzyme, whereas activities of malic enzyme and glycolytic enzymes were not different compared with zinc‐adequate rats on the coconut oil diet. In contrast, rats receiving the linseed oil diet had similar triglyceride concentrations regardless of zinc status, and activities of lipogenic enzymes and glycolytic enzymes were not different between the two groups. Zinc‐deficient rats fed either type of dietary fat exhibited statistically significant correlations between activities of FAS, G6PDH, 6PGDH and concentrations of saturated and monounsaturated fatty acids in liver. The concentrations of serum lipids were elevated in zinc‐deficient rats fed either type of dietary fat. These results demonstrate that fatty liver in zinc‐deficient rats on the coconut oil diet is caused by elevated activities of lipogenic enzymes, and not by disturbed lipid secretion from liver. Dietary linseed oil prevents both the elevation of lipogenic enzyme activity and fatty liver in zinc‐deficient rats.
Synthesis and metabolism of sodium 3α,7α‐dihydroxy‐25,26‐bishomo‐5β‐cholane‐26‐sulfonate in the hamster
Authors: Mikami Takahiro , Mosbach Erwin H. , Cohen Bertram I. , Ayyad Nariman , Yoshii Michiko , Kihira Kenji , Hoshita Takahiko 
Published: November 2006

AbstractThis paper reports the chemical synthesis of a new bile acid analogue, namely sodium 3α,7α‐dihydroxy‐25,26‐bishomo‐5β‐cholane‐26‐sulfonate (bishomoCDC‐sul) from chenodeoxycholic acid and describes its metabolism in the hamster. The structure of the new compound was confirmed by proton and carbon‐13 nuclear magnetic resonance spectroscopy. After intravenous infusion of [3H]‐labeled sulfonate into bile fistula hamsters, it was extracted by the liver and secreted into the bile; more than 65% of the radioactivity was recovered in the bile within 1 h. Following intraduodenal administration of the [3H]sulfonate and [14C]chenodeoxycholyltaurine, both compounds were excreted into the bile more slowly; only 41 and 43% of the radioactivity, respectively, were recovered in the bile during the four‐hour experimental period. In contrast, when the labeled compounds were injected into the terminal ileum, both the sulfonate and chenodeoxycholyltaurine were repidly absorbed and secreted into the bile; 84 and 97%, respectively, of the radioactivity were recovered during a four‐hour period. Chromatographic analysis demonstrated that in these short‐term experiments most (>95%) of the sulfonate was secreted into the bile without biotrasformation regardless of the route of administration. When infused intravenously at increasing doses, bishomoCDC‐sul induced cholestasis at an infusion rate of 1 μmol/min/kg. These results suggest that sodium 3α,7α‐dihydroxy‐25,26‐bishomo‐5β‐cholane‐26‐sulfonate was absorbed from the terminal ileum by active transport, extracted by the liver, and secreted into the bile in a manner similar to that of the natural bile acids.
Chemical and enzymatic preparation of acylglycerols containing C18 furanoid fatty acids
Authors: Lie Ken Jie Marcel S. F. , Syed‐Rahmatullah M. S. K. 
Published: November 2006

AbstractC18 furanoid triacylglycerol [glycerol tri‐(9,12‐epoxy‐9,11‐octadecadienoate)] was prepared by chemical transformation of triricinolein isolated from castor oil. The procedure involved oxidation, epoxidation and cyclization of the epoxy‐keto intermediate with sodium azide and ammonium chloride in aqueous ethanol. The furanoid triacylglycerol was also obtained by esterification of C18 furanoid fatty acid with glycerol using Novozyme 435 (Novo Nordisk A.S., Bagsvaerd, Denmark) as biocatalyst. When Lipozyme (Novo Nordisk A.S.) was used, a mixture of the furanoid 1(3)‐rac‐monoacylglycerol and 1,3‐diacylglycerol was obtained. In order to obtain the C18 furanoid 1,2(2,3)‐diacylglycerol, selective hydrolysis of the furanoid triacylglycerol was achieved using procine pancreatic lipase intris(hydroxymethyl) methylamine buffer. Interesterification of triolein with methyl C18 furanoid ester in the presence of Lipozyme showed maximum incorporation of 34% of furanoid fatty acid. Extension of the interesterification to vegetable oils (olive, peanut, sunflower, corn and palm oil) allowed a maximum of 24% furanoid acid incorporation to be achieved.
Comparative studies of metabolism of 4‐desmethyl, 4‐monomethyl and 4,4‐dimethyl sterols inManduca sexta
Authors: Svoboda James A. , Ross Samir A. , Nes W. David 
Published: November 2006

AbstractTo investigate the metabolism and possible deleterious effects of 4‐methyl and 4,4‐dimethyl steroids inManduca sexta, the 4,4‐dimethyl sterols lanosterol and cycloartenol, the 4‐methyl sterol obtusifoliol and the 4,4‐dimethyl pentacyclic triterpenoid α‐amyrin were fed in an artificial agar‐based diet at various concentrations. Utilization and metabolism of these four compounds were compared with sitosterol, stigmasterol, brassicasterol, ergosterol and 24‐methylenecholesterol, 24‐alkyl sterols that are readily dealkylated and converted to cholesterol inManduca and in most phytophagous insects. None of the 4‐methylated compounds significantly inhibited development except at very high dietary concentrations. The Δ24‐bonds of lanosterol and cycloartenol were effectively reduced by theManduca Δ24‐sterol reductase enzyme, as is the Δ24‐bond of desmosterol which, in most phytophagous insects, is an intermediate in the conversion of sitosterol, stigmasterol and other C28 and C29 phytosterols to cholesterol. On the other hand, the 24‐methylene substituent of obtusifoliol was not dealkylated. Each of the 4‐desmethyl C28 and C29 sterols was readily converted to cholesterol, and a significant amount of 7‐dehydro‐cholesterol was derived from ergosterol metabolism. The reason for the differences in substrate specificity of these sterols is not clear, but the information may be useful in the development of new, specific, mechanism‐based inhibitors of sterol metabolism.
Lipids of selected molds grown for production of n−3 and n−6 polyunsaturated fatty acids
Authors: Kendrick Andrew , Ratledge Colin 
Published: November 2006

AbstractThe lipid classes and component fatty acids of seven fungi were examined. Three marine fungi,Thraustochytrium aureum, Thraustochytrium roseum andSchizochytrium aggregatum (grown at 30, 25 and 25°C, respectively), produced less than 10% lipid but contained docosahexaenoic acid (DHA) up to 30% and eicosapentaenoic acid (EPA) up to 11% of the total fatty acids.Mortierella alpinapeyron produced 38% oil containing solely n‐6 polyunsaturated fatty acids (PUFA) with arachidonic acid (AA) at 11% of the total fatty acids.Conidiobolus nanodes andEntomorphthora exitalis produced 25% oil and contained both n−3 and n−6 PUFA, with AA at 16% and 18%, respectively.Saprolegnia parasitica produced 10% oil and contained AA and EPA, respectively, at 19% and 18%. The triacylglycerol fraction always represented the major component at between 44% and 68% of the total lipid. Each fungus, exceptT. aureum, had the greatest degree of fatty acid unsaturation in the phospholipid fraction. The triacylglycerol fraction ofT. aureum was the most unsaturated with DHA representing 29% (w/w) of all fatty acids present. The presence of the enzyme ATP:citrate lyase correlated with the ability of molds to accumulate more than 10% (w/w) lipid when the fungi were grown in nitrogen‐limiting media. In those molds that failed to accumulate more than 10% lipid, the enzyme was absent.
Linoleoyl‐enriched triacylglycerol species increase in maternal liver during late pregnancy in the rat
Authors: Chen Zhen‐Yu , Yang Jilin , Menard Chantale R. , Cunnane Stephen C. 
Published: November 2006

AbstractIn view of the previously reported changes in the fatty acid composition of maternal liver triacylglycerols in late pregnancy, changes in the composition of maternal liver triacylglycerol species were assessed in rats fed a semipurified diet during pregnancy. Between day 18 and day 21 of pregnancy, total maternal liver triacylglycerols increased by 50%. Triacylglycerol species with a total acyl carbon number (C) of 50 or 60 (C50, C60) remained unchanged while C48 and C52–C58 were relatively increased. The individual triacylglycerol species containing one, two or three linoleoyl moieties were incompletely recovered using a polar high temperature gas‐liquid chromatography (GLC) column. Nevertheless, at day 21 compared to day 18, the linoleoyl‐containing species were relatively increased by 62–463%, while tripalmitin was decreased by 38%. Our data suggest that despite an adequate intake of linoleic acid (25 g/kg in the diet), maternal hepatic triacylglycerol content of linoleic acid decreased during mid‐pregnancy but increased significantly toward term possibly in preparation for the transfer of linoleic acid to the neonate during lactation.