bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphatidylethanolamine metabolism in rats fed a low methionine, choline‐deficient diet
Authors: Lyman R. L. , Sheehan G. , Tinoco J. 
Published: December 2006

AbstractThe metabolism of phosphatidylethanolamine (PE) was studied in male rats fed a low methionine diet for 7 days with or without supplemental choline. Groups of animals were injected with 2‐14C‐ethanolamine and killed at intervals thereafter up to 72 hr. Liver phospholipids were isolated, and PE and phosphatidylcholine (PC) were separated by argentation chromatography into diene (18∶2), tetraene (20∶4) and hexaene (22∶6) fractions. Fatty acid composition and the distribution of radioactivity and specific activity in the total phospholipids and in the fractions were determined. Choline deficiency did not affect total liver phospholipid, but it did increase the amount of PE and decreased that of PC. The major effect of the deficiency on phospholipid fatty acids was to decrease the proportion of PE arachidonate and to increase that of docosahexaenoate. Ethanolamine incorporation into liver PE of deficient rats was only slightly less than in the controls, but loss of the radioactivity from the PE was slower. Ethanolamine radioactivity appearing in the PC of deficient rats was about half that of the controls, even though specific activities of the PE precursors were similar to the control rats. Choline deficiency increased the biological half‐lives of the total PE and its fractions. Although the proportion of PE tetraenoic fraction was reduced, the total amount of this liver PE fraction in deficient rats was not affected. However the amount of hexaenoic fraction was doubled, and it accounted for most of the increased quantity of liver PE seen in deficient animals. The results suggested that in choline deficiency PE synthesis was delayed but not appreciably suppressed, and that limited availability of methionine for methylating the PE fractions in their proper proportions affected the concentrations of the PE fractions and impaired their normal conversion to PC.
Biosynthesis of liver glycerolipids from normal and essential fatty acid‐deficient rats:3H‐glycerol and 1‐14C linoleic acid incorporation
Authors: de Tomas Maria Elena , Mercuri Osvaldo 
Published: December 2006

AbstractNormal and essential fatty acid (EFA)‐deficient rats were injected via the portal vein with a labeled solution containing3H‐glycerol and 1‐14C‐linoleic acid during a 1 min period. Livers were immediately frozen, pulverized, and the lipids extracted and fractioned by thin layer chromatography. The incorporation of3H‐glycerol and 1‐14C‐linoleic acid into the different lipid fractions was measured, and the per cent distribution and specific radioactivity determined. A parallel increase was found between the specific activity and the amount of3H‐glycerol incorporated into 1,2‐diglycerides, triglycerides, lecithin and cephalin from EFA‐deficient and normal rats. Since the amount of glycerol in each fraction studied was quite similar in both groups of rats, these findings can explain the increase in the specific activity observed in the EFA‐deficient rats. Nevertheless these facts do not necessarily imply an increased turnover rate of these molecules, since we do not know the specific radioactivity of the 1,2‐diacylglycerol precursors. A remarkable increase in the specific radioactivity of the14C‐linoleic acid incorporated into lipid fractions from EFA‐deficient rats compared with control rats was observed. While the amount of 1‐14C‐linoleic acid incorporated into neutral lipids was similar in both groups of rats, a statistically significant increase in the amount of the label incorporated into phospholipids from EFA‐deficient rats was observed. These facts suggest an increased turnover rate of the radiolinoleic acid into phospholipid molecules from EFA‐deficient rats via deacylation‐reacylation pathway.
Microbiological studies investigating mutagenicity of deep frying fat fractions and some of their components
Authors: Scheutwinkel‐Reich M. , Ingerowski G. , Stan H. J. 
Published: December 2006

AbstractIn this study, the Salmonella/microsome mutagenicity test according to Ames et al. (Mutation Res. 31∶347, 1975) was performed in order to detect possible mutagenicity of oxidized deep frying fat fractions. Furthermore, the mono‐, di‐, tri‐ and tetrahydroxyoctadecanoic acids and the hydroperoxide of linoleic acid were investigated as model test substances. The Ames assay was carried out with and without metabolic activation including preincubation and liquid culture procedures as described by Mitchell (Mutation Res. 54∶1, 1978). The results show no mutagenic effects for the oxidized fractions of deep frying fats nor for the model test substances. At higher concentrations, however, limited test reliability resulted from direct toxic effects on bacterial growth.
Experimental nephrotic syndrome in the rat induced by puromycin aminonucleoside: Hepatic synthesis of lipoproteins and apolipoproteins
Authors: Gherardi E. , Messori M. , Rozzi R. , Calandra S. 
Published: December 2006

AbstractHepatic synthesis of lipoproteins and apolipoproteins was investigated in male Wistar rats with severe nephrotic syndrome induced by puromycin aminonucleoside by incubating liver slices with a mixture of14C‐amino acids. Labeled lipoproteins were separated by preparative ultracentrifugation from the incubation medium after the addition of carrier plasma. The incorporation of14C‐amino acids into very low density lipoproteins (VLDL) (1.006 g/ml), low density lipoproteins (LDL) (1.006–1.063 g/ml) and high density lipoproteins (HDL) (1.063–1.210 g/ml) was increased in nephrotic liver 6.1‐, 5.7‐ and 5.0‐fold, respectively. The measurement of radioactivity associated to apolipoproteins isolated by SDS‐PAGE documented an increased incorporation into apolipoprotein E (apoE) of nephrotic VLDL (33.1% vs 20% of the total radioactivity incorporated into VLDL apoproteins) and a markedly increased incorporation into apolipoprotein A‐I (apoA‐I) of nephrotic HDL (44.3% vs 16.3% of the total radioactivity incorporated into HDL apoproteins). In nephrotic liver, the total incorporation of amino acids into apolipoproteins (apoVLDL+apoLDL+apoHDL) was increased 12.6 times for apoA‐I, 6.4 times for apoB, 5.0 times for apoE, 4.2 times for apoC+apoA‐II and 2.5 times for apoA‐IV. We suggest that, in nephrotic liver: (a) the synthesis of VLDL, LDL and HDL is increased, and (b) the total synthesis of apoA‐I is selectively increased when compared to that of the other apolipoproteins.
A rapid procedure for screening and isolating oxygenated free fatty acid metabolites from plants and natural waters
Authors: Van Rogers A. , Van Aller Robert T. , Pessoney George F. , Watkins Edward J. , Leggett Harold G. 
Published: December 2006

AbstractA rapid method of isolating a relatively pure fraction of oxygenated fatty acids from plants and natural waters is described. These metabolites were isolated from aqueous extracts using octadecylsilyl silica in a reverse‐phase batch extraction method. The extraction method, together with reverse‐phase analytical high pressure liquid chromatography (HPLC), was used to establish a routine screening method for the presence of these compounds in a variety of natural sources. A reverse‐phase preparative HPLC purification method is also described.
Reduced plasma lecithin cholesterol acyl transferase activity in rats fed iron‐deficient diets
Authors: Ananda Rao G. , Thomas Crane R. , Larkin Edward C. 
Published: December 2006

AbstractAn iron‐deficient diet containing no fat (FF−Fe) or containing either 14% hydrogenated coconut oil (HCNO−Fe) or 14% corn oil (CO−Fe) was fed to separate groups of rats for 10 weeks. In the control group, the corresponding iron‐supplemented diets were fed FF+Fe, HCNO+Fe, CO+Fe. When rats were fed iron‐deficient diets, their plasma lecithin cholesterol acyl transferase (LCAT) activity was significantly reduced as compared to controls. Their plasma also contained relatively more cholesteryl esters (CE) than free cholesterol (CH). In rats fed FF+Fe and CO+Fe diets, plasma contained similar levels of CE and CH. In those fed HCNO+Fe diet, plasma had 40% less CE than CH. Red cell CH content was significantly greater in the CO−Fe group. Iron deficiency, as indicated by low blood hemoglobin (Hb) and hematocrit (Hct) values, was also observed only in this group. The triglyceride and phospholipid contents of plasma in rats fed iron‐deficient diets were significantly lower than of those in the control groups. Thus, changes in LCAT activity and CE/CH ratio in plasma showed the effect of iron‐deficient diet consumption even before the blood Hb and Hct levels were reduced.
The effect of dietary α‐linolenic acid in the rat on fatty acid profiles of immunocompetent cell populations
Authors: Marshall Lisa A. , Johnston Patricia V. 
Published: December 2006

AbstractAnalysis of diet‐induced fatty acid changes in the major phospholipids of various immune cell populations has not been previously documented, particularly modifications induced by dietary α‐linolenic acid. Rats were fed purified diets containing either 10% corn oil (CO), 10% linseed oil (LO) or 10% soybean oil‐linseed mixture (SL) for 8 weeks. The α‐linolenic to linoleic acid ratios of the diets were 1∶32, 1∶1 and 3∶1, respectively. Fatty acid analysis of cell populations isolated from the spleen, thymus, thoracic cavity and peripheral blood phospholipids showed increases in ω3 fatty acids accompanied by decreases in the ω6 fatty acids when diets high in α‐linolenic to linoleic acid ratios were fed. The extent of change observed was dependent on the magnitude of the α‐linolenic to linoleic acid ratio. Both magnitude of change and the specific fatty acids altered varied with the cell population examined.
The effects of partially hydrogenated marine oils on the mitochondrial function and membrane phospholipid fatty acids in rat heart
Authors: Blomstrand Rolf , Svensson Lennart 
Published: December 2006

AbstractThe influence of dietary partially hydrogenated marine oils containing docosenoic acid on rat heart mitochondrial membrane phospholipid fatty acid composition was studied with particular reference to cardiolipin and oxidative phosphorylation. Five groups of male weanling rats were fed diets containing 20% (w/w) peanut oil (PO), partially hydrogenated peanut oil (HPO), partially hydrogenated Norwegian capelin oil (HCO), partially hydrogenated herring oil (HHO), and rapeseed oil (RSO) for 10 weeks. All the cardiac phospholipids investigated were influenced by the experimental diets. An increased amount of arachidonic acid observed in phosphatidylethanolamine (PE) after feeding partially hydrogenated oils suggests a changed regulation of the arachidonic acid metabolism in comparison with PO treatment. 22∶1 originating from the dietary oils was incorporated only to a small extent into phosphatidylcholine (PC) and PE. A selective incorporation of 18∶1 isomers into the 1‐ and 2‐positions of PC and PE with respect to geometry and position of the double bond was observed. Large amounts of 18∶1trans were incorporated into the 1‐position of PC and PE, irrespective of the amount of 18∶2 supplemented to the diets, replacing a considerable proportion of stearic acid in this position. After feeding HHO and RSO, the content of 22∶1 in mitochondrial cardiolipin of rat heart was found to be 3% (mainly cetoleic acid) and 10% (mainly erucic acid), respectively, indicating a high affinity forcis isomers of 22∶1, but also a considerable resistance against incorporation oftrans isomers was observed. The ability of rat cardiac mitochondria to oxidize palmitoylcarnitine and to synthesize ATP was depressed after feeding HHO and RSO. Dietarycis isomers of 22∶1 seem to have a specific ability to interfere with cardiac ATP synthesis and also to alter the fatty acid composition of cardiolipin of rat heart.
Photosensitized oxidation of methyl linoleate monohydroperoxides: Hydroperoxy cyclic peroxides, dihydroperoxides, keto esters and volatile thermal decomposition products
Authors: Neff W. E. , Frankel E. N. , Selke E. , Weisleder D. 
Published: December 2006

AbstractPrevious studies of lipid secondary oxidation products have been extended to 6‐membered hydroperoxy cyclic peroxides from the singlet oxygenation of a mixture of 9‐ and 13‐hydroperoxides from autoxidized methyl linoleate. The oxidation product was fractionated by silicic acid chromatography with diethyl ether/hexane mixtures, and selected fractions were separated by polar phase high performance liquid chromatography. Products characterized by thin layer chromatography, gas liquid chromatography, ultraviolet, infrared, nuclear magnetic resonance and mass spectrometry included: 6‐membered cyclic peroxides (13‐hydroperoxy‐9,12‐epidioxy‐10‐ and 9‐hydroperoxy‐10,13‐epidioxy‐11‐octadecenoates), dihydroperoxides (8,13‐ and 9,14‐dihydroperoxyoctadecadienoates) and keto dienes (9‐ and 13‐oxooctadecadienoates). The 6‐membered hydroperoxy cyclic peroxides are apparently formed by 1,4‐addition of singlet oxygen to 9‐ and 13‐hydroperoxides withtrans, trans‐conjugated diene systems. Thermal decomposition of the 6‐membered hydroperoxy cyclic peroxides at 200 C produced methyl 9‐oxononanoate and hexanal as the major volatiles. Other volatiles included 2‐pentylfuran, pentane, 4‐oxo‐2‐nonenal, methyl furanoctanoate and methyl 9,12‐dioxo‐10‐dodecenoate.
Covalent binding of peroxidized linoleic acid to protein and amino acids as models for lipofuscin formation
Authors: Shimasaki Hiroyuki , Ueta Nobuo , Privett O. S. 
Published: December 2006

AbstractThe fluorescent substances produced by the reaction of linoleic acid hydroperoxides (LOOH) with ca. 20 different amino acids and bovine serum albumin (BSA) were studied. Only the amino acids, lysine, glycine, arginine, histidine and phenylalanine, gave products with strong fluorescent properties. Products of lysine had a fluorescence intensity of ca. 10 times those of glycine and 100 times those of phenylalanine. The N‐acylation of amino acids greatly reduced the fluorescence of the products of the reaction except lysine and arginine. The fluorescence of the products of the reaction of LOOH with N‐acetyl BSA was only ca. 25% of the control BSA under the same conditions. It appeared that the substances formed from the reaction of LOOH with BSA were crosslinked polymers as evidenced by column chromatography and polyacrylamide gel electrophoresis. These products were insoluble in common organic solvents and their fluorescent intensities correlated well with the thiobarbituric acid (TBA) test. These observations appear to be highly important in the formation of lipofuscin substances, particularly those associated with the aging pigments which accumulate during aging in mammalian tissues.
Quantitative analysis of lipid classes by liquid chromatography via a flame ionization detector
Authors: Phillips F. C. , Erdahl W. L. , Privett O. S. 
Published: December 2006

AbstractA method is described for the direct quantitative analysis of the lipid classes of mammalian tissue lipids using high performance liquid chromatography (HPLC) with a flame ionization detector (FID). The lipid is extracted from the tissue with chloroform/methanol after deactivation of hydrolytic enzymes and removal of nonlipid substances by extraction with hot dilute acetic acid (0.05N). Separation of the lipid classes is performed with a column (45 cm × 0.2 cm id) of 8 μm silica (Spherisorb, Phase Sep, Hauppague, NY) treated with concentrated ammonium hydroxide at a solvent flow rate of 0.5 ml/min, which requires a pressure of ca. 900 psi. Cholesteryl esters (CE) and triglycerides (TG) are eluted first with Skellysolve B/methylene chloride (1∶1, v/v); cholesterol (CH) is eluted with chloroform/methylene chloride (1∶2, v/v) and the phospholipids with methanol containing 6% ammonium hydroxide added to the latter solvent in a linear gradient. The neutral lipids are eluted in ca. 12 min and the phospholipids in an additional 30 min. The relative amount of each lipid class was determined from standard curves of the peak areas obtained according to response factors using erucyl alcohol as an internal standard. The method was applied to samples of kidney, liver and serum of rats. Duplicate analyses were generally within ca. 1.0% and good agreement was obtained in the analysis of the lipid classes of Azolectin and liver mitochondria lipid compared to thin layer chromatography (TLC) via photodensitometry of charred spots or phosphorus analysis of recovered phospholipids.
Metabolism of arachidonic acid in leukocytes: Isolation of a 5,15‐dihydroxy‐eicosatetraenoic acid
Authors: Borgeat Pierre , Picard Serge , Drapeau Jean , Vallerand Pierre 
Published: December 2006

AbstractA novel metabolite of arachidonic acid was isolated from incubations of peripheral blood leukocytes with the fatty acid and the ionophore A23187. The compound was purified by high performance liquid chromatography and identified by ultraviolet photometry and gas chromatography‐mass spectrometry as a 5,15‐dihydroxy‐6,8,11,13‐eicosatetraenoic acid. The compound was also isolated from incubations of human leukocytes with the 15S‐hydroperoxy‐5,8,11,13(Z,Z,Z,E)‐eicosatetraenoic acid, suggesting a double dioxygenation mechanism in the formation of this new metabolite of arachidonic acid. A 5S,15S‐dihydroxy‐6,8,11,13(E,Z,Z,E)‐eicosatetraenoic acid was obtained from incubations of 5S‐hydroxy‐6,8,11,14(E,Z,Z,Z)‐eicosatetraenoic acid with the soybean lipoxygenase and reduction with stannous chloride, and was used as reference compound.
Fatty acid chain length combinations in ascitic fluid triglycerides containing lymphatic absorbed medium‐chain fatty acids
Authors: Christophe A. , Verdonk G. , Mashaly M. , Sandra P. 
Published: December 2006

AbstractInformation on the fatty acid chain length combinations in lymph triglycerides containing medium‐chain fatty acids was obtained combining the fatty acid composition and the carbon number composition of triglycerides from ascitic fluid of patients on medium‐chain triglyceride‐containing diets. In these triglycerides, the major part of the medium‐chain fatty acids was present in combination with long‐chain fatty acids. These results indicate that part of the lymphatic absorbed medium‐chain fatty acids are absorbed as triglycerides which also contain long‐chain fatty acids.
Enzymatic hydrolysis in vitro of thermally oxidized sunflower oil
Authors: Yoshida Hiromi , Alexander J. C. 
Published: December 2006

AbstractThe hydrolysis of thermally oxidized sunflower oil by pancreatic lipase was studied in relation to chemical changes in the acylglycerols. Four classes of compounds (monomers, dimers, trimers and polymers) formed from the acylglycerols were separated from the heated oils by column chromatography on silica gel, and further verified by thin layer chromatography. Each fraction, after analyses for generaly properties, was subjected to a time course study of hydrolysis by pancreatic lipase over a 30‐min period. After 70 hr of heating, the amount of hydrolysis for the acylglycerol dimers was only about half that of the monomers, and that for the trimers was, in turn, about one‐third that of the monomers. The polymers were the least hydrolyzed and showed no further reaction after 5 min. The reduction in enzymatic hydrolysis of isolated fractions from the thermally oxidized oils indicates structural differences, related to formation of polar compounds and polymerization products. Adverse effects on animals from feeding these materials can be attributed partly to inhibition of hydrolysis resulting in less available energy.
Digitonin‐precipitable sterols as a measure of cholesterol biosynthesis: Contradictory results
Authors: Tabacik C. , Aliau S. , Crastes de Paulet A. 
Published: December 2006

AbstractIn experiments with 4 different types of cells, we evaluated the cholesterogenic activity by incorporation of14C‐acetic acid into cholesterol and digitonin‐precipitable sterols. In every case, the cholesterogenesis appeared considerably faster when expressed as digitonid than when expressed as real cholesterol production, and sometimes the data obtained by the 2 methods were contradictory. Detailed analysis of both digitonid components and nonprecipitable radioactive metabolites showed that a very variable fraction of methyl sterols (including bifunctional methyl sterols) co‐precipitates with the C‐27 sterols. In cholesterol regulation studies and particularly when the cells exhibit a low cholesterogenesis, the digitonin method is unsuitable and can lead to erroneous interpretations.
The effect of vitamin C on in vivo lipid peroxidation in guinea pigs as measured by pentane and ethane production
Authors: Kunert Karl‐Josef , Tappel Al. L. 
Published: December 2006

AbstractMeasurements of pentane and ethane as indices of in vivo lipid peroxidation were made on samples of breath from vitamin C‐sufficient and vitamin C‐deficient guinea pigs injected with 23 μl carbon tetrachloride (CCl4)/100 g body wt. Vitamin C‐deficient animals produced significantly more pentane and ethane after CCl4 treatment than did vitamin C‐sufficient guinea pigs. Pretreatment of vitamin C‐deficient animals with 75 mg ascorbic acid/100 g body wt significantly lowered both pentane and ethane evolution. Protection against in vivo lipid peroxidation similar to that provided by ascorbic acid was also found when vitamin C‐deficient guinea pigs were pretreated with isoascorbic acid, reduced glutathione, α‐tocopherol or β‐carotene. When animals were pretreated with the radical scavenger mannitol, a protective effect was also observed as measured by pentane evolution.
Severe fatty liver in rats fed a fat‐free ethanol diet, and its prevention by small amounts of dietary arachidonate
Authors: Goheen Steven C. , Larkin Edward C. , Rao G. Ananda 
Published: December 2006

AbstractRats were fed ethanol and a fat‐free diet for 30 days to determine whether dietary fat is needed for the development of fatty liver. The severity of fatty liver was similar to that of rats fed an isocaloric diet with 35% fat. Small amounts (29 mg/day) of dietary arachidonic acid prevented alcoholic fatty liver. Rats fed either the alcohol (AF) or control (CF) fat‐free diets developed essential fatty acid deficiency (EFAD) as measured by the triene/tetraene ratio of liver and plasma lipids. Rats fed arachidonic acid (AA, alcohol and CA, control diets) did not develop EFAD. Although EFAD alone did not cause the development of fatty liver, the combination of dietary ethanol and EFAD did. The ratios of 16∶1/16∶0 and 18∶1/18∶0 in liver lipids indicated that desaturase enzymes were less active and lipogenesis was reduced in rats fed the AA diet compared to those fed the AF diet. In contrast, stimulated lipogenesis appears to have been the cause of fatty liver in rats fed the AF diet.
Potentiating effect of 5,8,11‐eicosatrienoic acid on human platelet aggregation
Authors: Lagarde M. , Burtin M. , Sprecher H. , Dechavanne M. , Renaud S. 
Published: December 2006

Abstract5,8,11‐Eicosatrienoic acid (20∶3ω9), a fatty acid increased in the platelet phospholipids of man and animals fed saturated fats, was either added to human platelets simultaneously with the aggregating agents, or incorporated into the platelet phospholipids by preincubation. 20∶3ω9 markedly increased the response of platelets to all aggregating agents tested when added simultaneously with the agent, but solely to thrombin and ionophore, after incorporation into the platelet phospholipids. The potentiating effects of 20∶3ω9 on thrombin aggregation do not appear to be related to prostaglandin formation, but rather to the production of a monohydroxy derivative through the lipoxygenase pathway.