bluuebunny/crossref_metadata_2025_split huggingface dataset:
The acute effects of a single very high dose of n−3 fatty acids on plasma lipids and lipoproteins in healthy subjects
Authors: Svaneborg N. , Møller J. M. , Schmidt E. B. , Varming K. , Lervang H. H. , Dyerberg J. 
Published: November 2006

AbstractForty healthy volunteers were allocated in a double blind, randomized study to receive either 20 g of n−3 polyunsaturated fatty acids (PUFA) or 20 g of n−6 PUFA at their evening meal. The effect on plasma lipids and lipoproteins of this single dose of fish oilvs. corn oil was studied the next morning, 14 h after ingestion. Plasma triglycerides and very low density lipoprotein‐cholesterol significantly decreased (33%) after n−3 PUFA (P<0.001), and significantly (P<0.01) more than after intake of n−6 PUFA. The decrease in plasma triglycerides after n−3 PUFA ingestion was more pronounced in subjects with higher baseline levels of triglycerides (P<0.001). Total cholesterol decreased after both supplements, but did not differ between the supplements. Low density lipoprotein‐cholesterol did not change, and high density lipoprotein‐cholesterol significantly decreased in subjects given n−3 PUFA compared to baseline, but not when compared to subjects receiving n−6 PUFA. In conclusion, we have shown that a single very high dose of n−3 PUFA has a pronounced hypotriglyceridemic effect, which is directly related to the initial plasma level.
Tissue phospholipid fatty acid composition in genetically lean (Fa/−) or obese (fa/fa) zucker female rats on the same diet
Authors: Guesnet Ph. , Bourre J. ‐M. , Guerre‐Millo M. , Pascal G. , Durand G. 
Published: November 2006

AbstractThe fatty acid composition of serum total lipids, of phospholipids of various organs (liver, heart, kidney), and of nervous structures (brain, retina, sciatic nerve, myelin, synaptosomes) have been compared in lean (Fa/−) and genetically obese (fa/fa) Zucker female rats. Both received a standard commercial diet including 37% of 18∶2n−6 and 5% of n−3 polyunsaturated fatty acids (PUFA), 1.7% of which were in the form of 20∶5n−3 and 22∶6n−3. In comparison with lean rats, the results for the obese rats pointed out (i) no difference in the fatty acid composition of nervous structures: (ii) a decrease of 18∶2n−6 (from −8% to −35%) and of 20∶4n−6 (from −9% to −49%) in serum, liver and in kidney; this was compensated for by an increase in 20∶3n−6 (from +30% to +320%) and in total n−3 PUFA (from +68% to +76%); (iii) a decrease of 20∶4n−6 (−18%) and of 22∶6n−3 (−24%) in heart compensated for by an increase in 18∶2n−6 (+39%) and in 20∶3n−6 (+233%); and (iv) constant levels of total PUFA (n−6 and n−3) in the various fractions studied, except in serum where this level decreased (−23%). Finally, except for the nervous structures, tissue phospholipids of obese rats included a lower proportion of 20∶4n−6 and a higher proportion of 20∶3n−6. This resulted in a significant reduction in the 20∶4n−6/20∶3n−6 ratio; by contrast, the 20∶3n−6/18∶2n−6 ratio increased. The results suggest that in Zucker rats, the obese character (fa/fa) affects the desaturation‐elongation process of 18∶2n−6 to 20∶4n−6 by specifically decreasing Δ5‐desaturase activity.
Exchange of free cholesterol between plasma and erythrocytes from hyperthyroid and hypothyroid ratsin Vitro
Authors: Ruggiero F. M. , Cafagna F. , Quagliariello E. 
Published: November 2006

AbstractIn our previous studies, we found that circulating thyroid hormone levels alter cholesterol partition between plasma and erythrocytes by changing the phospholipid content of erythrocytes (Ruggiero, F.M.,et al. (1984)Horm. Metabol. Res. 16, 37–40; Ruggiero, F.M.,et al. (1987)Lipids 22, 148–151). As an extension of this work, we now followed the exchange of free cholesterol between plasma and erythrocytes in control, hyperthyroid and hypothyroid rats under various experimental conditionsin vitro. In control rats, erythrocytes incubated with plasma at 37°C for 4 hr lose 10% of cholesterol which was esterified by lecithin: cholesterol acyltransferase (LCAT) present in the plasma. In hyperthyroid rats, erythrocytes incubated with plasma lose 30% of cholesterol within the same time. By contrast, in the case of hypothyroid rats incubation for 4 hr was necessary to transfer 24% of free cholesterol from plasma to erythrocytes. Inhibition of cholesterol esterification did not affect the loss of erythrocyte cholesterol in control and in hyperthyroid rats. Ca2+ increased the LCAT activity in the plasma of these rats. The findings shed light on the role of thyroid hormones in regulating cholesterol levels in plama through active cholesterol transfer between plasma and erythrocytes.
The differential effect of eicosapentaenoic acid and oleic acid on lipid synthesis and VLDL secretion in rabbit hepatocytes
Authors: Benner Kent G. , Sasaki Anna , Gowen Dale R. , Weaver Alice , Connor William E. 
Published: November 2006

AbstractThe suppression of plasma very low density lipoprotein (VLDL) triglyceride levels by dietary fish oils rich in polyunsaturated n−3 fatty acids has been attributed to decreased hepatic VLDL secretion. To investigate the effect of n−3 fatty acids on lipid metabolism and VLDL secretion in a tissue culture system, we incubated rabbit hepatocytes with oleic acid and eicosapentaenoic acid (EPA) and examined [3H]glycerol and [14C]fatty acid incorporation into hepatocyte triglyceride and phospholipid and into media VLDL. Glycerol incorporation studies showed that EPA failed to stimulate VLDL triglyceride secretion from hepatocytes as occurred with oleic acid (P<0.05). Oleic acid preferentially enhanced hepatocyte triglyceride synthesis while EPA stimulated significantly phospholipid synthesis (P<0.01). Varying the relative concentrations of oleic acid and EPA at a constant total fatty acid concentration corroborated preferential triglyceride synthesis from oleic acid. Synthesis shifted predominantly to phospholipids with increasing concentrations of EPA and lower levels of oleic acid. Incorporation of the [14C]fatty acids (800 μM) followed similar patterns: 87% of [14C]oleic acid was incorporated into hepatocyte triglyceride and 44% of [14C]EPA was assimilated in hepatocyte phospholipid (p<0.001). Fatty acids at trace concentrations (53 nM) showed a more divergent pattern of lipid incorporation: 60% of [14C]oleic acid was incorporated into triglyceride while 91% of [14CEPA was incorporated into phospholipid (p<0.001). We conclude that in primary rabbit hepatocyte culture, which appears to be a useful model to study lipid metabolism and VLDL secretion, EPA is avidly incorporated into phospholipid while oleic acid predominantly becomes esterified in triglyceride. In addition, EPA, unlike oleic acid, fails to stimulate hepatocyte VLDL secretion. These divergent effects on hepatocyte lipid metabolism are, at least in part, likely to be responsible for fish oil induced suppression of plasma triglycerides.
Reduction in microalbuminuria in diabetics by eicosapentaenoic acid ethyl ester
Authors: Hamazaki Tomohito , Takazakura Eisuke , Osawa Kenzo , Urakaze Masaharu , Yano Saburo 
Published: November 2006

AbstractEicosapentaenoic acid (EPA) ethyl ester (1.8 g/d) was administered to 16 diabetic patients (5 insulin‐dependent and 11 noninsulin‐dependent diabetics) for 6 mon. EPA in total plasma fatty acids increased from 4.0±2.4 mol% (mean±SD) to 7.5±3.1 mol% (p<0.001). Albumin excretion, measured with spot urine, was significantly reduced from 65 to 36 mg/g creatinine (geometric means, p<0.001). Fasting blood sugar levels, glycohemoglobin, body weight and blood pressure did not change significantly during the study. There were also no significant changes in serum levels of creatinine, urea nitrogen, total cholesterol and triglycerides. Although no overt hemorrhage was observed in the patients, hematocrit was reduced from 42.6±2.8% to 41.0±3.9% (p<0.02). Ten other similar diabetic patients (4 insulin‐dependent and 6 non‐insulin‐dependent diabetics) were followed as a reference group, not concomitantly, for 6 mon with neither EPA ethyl ester nor placebo. The parameters mentioned above were not changed significantly in this group during 6 mon. EPA administration might retard the appearance of overt diabetic nephropathy.
On the effect of peroxisomal β‐oxidation and carnitine palmitoyltransferase activity by eicosapentaenoic acid in liver and heart from rats
Authors: Aarsland Asle , Lundquist Morten , Børretsen Bernt , Berge Rolf K. 
Published: November 2006

AbstractRepeated administration of highly purified eicosapentaenoic acid (as ethyl ester) resulted in a decrease in plasma triglycerides and high density lipoprotein (HDL) cholesterol. This was accompanied by a stimulation in the activities of carnitine palmitoyltransferase, fatty acyl‐CoA oxidase and peroxisomal β‐oxidation in the liver. The results suggest that the triglyceride‐lowering effect observed with eicosapentaenoic acid may be due to a reduced supply of fatty acids for hepatic triglyceride synthesis because of increased fatty acid oxidation. Eicosapentaenoic acid feeding marginally affected the triglyceride content of heart and mitochondrial and peroxisomal enzyme activities.
Intestinal absorption of retinol and retinyl palmitate in the rat. Effects of tetrahydrolipstatin
Authors: Fernandez Ester , Borgström Bengt 
Published: November 2006

AbstractThe aim of the present study was to characterize the intestinal absorption of retinol and retinyl palmitate in thoracic duct and bile duct fistulated rats and to investigate the effect of a simultaneously administered lipase inhibitor, tetrahydrolipstatin (THL). Absorption was determined as lymphatic recovery over a 24‐hr period, including an initial 12‐hr continuous intraduodenal infusion of either [11,12‐3H]retinol or [11,12‐3H]retinyl palmitate given in emulsified glyceryl trioleate or in mixed micellar solution of monoolein and oleic acid. From micellar dispersion, labeled retinol and retinyl palmitate were recovered in the lymph to 50–60% and both to the same extent. Administered in emulsified form, labeled retinol from fed retinyl palmitate was recovered to 47%, but retinol from fed retinol to only 18%. THL (10−4 M) in the infusate had no significant effect on the recovery of14C‐labeled oleic acid. The recovery of label from emulsified glyceryl tri[1‐14C]oleate was significantly decreased at this concentration of THL (76.5% vs 19.6% recovery). When administered in emulsified form, retinol absorption was not significantly affected by THL at 10−4 M, while retinyl palmitate absorption was very significantly decreased (5.0% compared to 47.8%). In the presence of THL, retinol absorption from retinyl palmitate in micellar solution was decreased (from 58% to 17%). Most of the retinol in the lymph extracts (72.2 to 91.3) was present as retinyl ester, regardless of the chemical and physical form of administration. Furthermore, THL did not induce any change in this pattern.
Liver phosphatidylcholine hydroperoxidation provoked by ethionine‐containing choline‐deficient diet in mice
Authors: Yoshida Lucia Satiko , Miyazawa Teruo , Fujimoto Kenshiro , Kaneda Takashi 
Published: November 2006

AbstractIt is shown that peroxidation of phosphatidylcholine (PC) is enhanced in liver of mice fed a hepatocarcinogenic choline‐deficient diet containing 0.1% w/w ethionine. Mice were divided into 4 groups and fed for 3 weeks one of the following diets: choline‐supplemented; choline‐supplemented containing ethionine; choline‐deficient; and choline‐deficient containing ethionine. Phosphatidylcholine hydroperoxide (PCOOH) of liver lipids was measured by high performance liquid chromatography using a chemiluminescence detector. Mice fed a choline‐deficient diet containing ethionine showed 6‐fold higher PCOOH levels than the choline‐supplemented control mice: the PCOOH/PC molar ratios of liver lipids were 32.3×10−5 and 5.6×10−5, respectively. In addition to this remarkable degree of lipid peroxidation in liver of mice fed the choline‐deficient diet containing ethionine, we also observed a significant liver fatty infiltration, a decrease in plasma and liver α‐tocopherol, and an increase in liver injury‐indicative enzyme activities. Also, marker enzymes for hepatocarcinogenesis, glucose‐6‐phosphatase and γ‐glutamyl transpeptidase were affected. These data suggest that enhanced hydroperoxidation of phosphatidylcholine may participate in hepatocarcinogenesis provoked by choline deficiency in the presence of ethionine.
Advantages of total lipid hydrogenation prior to lipid class determination on chromarods‐SIII
Authors: Shantha N. C. , Ackman R. G. 
Published: November 2006

AbstractThe changes in detector responses of lipid classes for standards and natural lipid samples after hydrogenation were investigated with the TLC/FID Iatroscan system using Chromarods‐SIII (Newman‐Howells Associates, Ltd., Midwales, U.K.). Samples included lipids of human plasma and erythrocytes, egg lipids, a fish oil concentrate and triacylglycerols of sea scallop, as well as standards (mono‐, di‐ and triacylglycerols, phosphatidylcholines, phosphatidylethanolamines, lysophosphatidylcholines, free fatty acid, and sterol). The duration of hydrogenation was increased from 45 min to 90 min for some samples to bring hydrogenation to completion. Since the detector response of a lipid class is known to depend on its relative position on the Chromarod, different solvent systems which would vary the migration rate were investigated. The increases in response after hydrogenation, given as relative percent increase (RI), were significant for all compounds examined (p<0.05), and ranged from 7 to 45%. Among the triacylglycerols, the fish oil and the sea scallop triacylglycerols with wide ranges of fatty acid composition had the highest RI while the other lipid classes did not differ from each other. Differences in the solvent systems did not affect the RI except for fish oil triacylglycerols. The precision of peak area measurements was usually better after hydrogenation. The combination of greater sample stability, greater response, improved resolution, and simpler choice of standards make hydrogenation a significant advance in TLC/FID quantification.
Serum apolipoproteins B and A‐I and naturally occurring fatty liver in dairy cows
Authors: Marcos Edgardo , Mazur Andrzej , Cardot Philippe , Rayssiguier Yves 
Published: November 2006

AbstractSerum lipids and apolipoprotein (apo) B and A‐I concentrations were determined in 164 dairy cows which had undergone liver biopsy in early lactation. The animals were divided into groups according to fatty liver severity on the basis of hepatic triglyceride content. The serum free fatty acid (FFA) concentration was higher in cows that developed fatty livers than in normal cows, and it correlated highly with liver triglycerides. Serum total cholesterol and triglyceride levels did not correlate with hepatic triglycerides. Both apo B and apo A‐I levels were significantly decreased in fatty liver cows. In particular, apo B levels showed a strongly negative correlation with liver triglycerides. The present results suggest that hepatic apolipoprotein synthesis is impeded in fatty liver cows.
Inevitable generation of primary alcohols during reduction of oxidized lipids with sodium borohydride
Authors: Nakamura Takashi , Maeda Hiroyuki , Takahashi Yoshino , Hama Yoichiro 
Published: November 2006

AbstractThis report deals with the fluorometric determination of fatty alcohols generated by the reduction of the ester linkage of lipids with NaBH4, and with the limitations of the reduction method for assaying oxidized lipids. Optimum conditions for the fluorometric analysis of primary and secondary alcohols using 1‐anthroyl nitrile were obtained. After reduction with NaBH4 in MeOH or in MeOH/benzene (8∶2, v/v), the formation of 1‐hexadecanol from a variety of palmitic acid esters was measured fluorometrically by reverse‐phase high‐performance liquid chromatography (HPLC): From glycerides and methyl palmitate, 1–3% (w/w) 1‐hexadecanol was produced and a trace was produced from cholesteryl palmitate (10 min, 21°C). 1‐Hexadecanol was never generated from palmitic acid. Although considerable improvement occurred with the choice of the solvent for the NaBH4 reduction, the generation of primary alcohols from ester lipids usually seems inevitable.
Lipid composition of the pineal organ from rainbow trout (Oncorhynchus mykiss)
Authors: Henderson R. J. , Bell M. V. , Park M. T. , Sargent J. R. , Falcon J. 
Published: November 2006

AbstractThe lipid composition of the pineal organ from the rainbow trout (Oncorhynchus mykiss) was determined to establish whether the involvement of this organ in the control of circadian rhythms is reflected by specific adaptations of lipid composition. Lipid comprised 4.9% of the tissue wet weight and triacylglycerols were the major lipid class present (47% of total lipid). Phosphatidylcholine (PC) was the principal polar lipid, and smaller proportions of other phospholipids and cholesterol were also present. Plasmalogens contributed 11% of the ethanolamine glycerophospholipids (EGP). No cerebrosides were detected. The fatty acid composition of triacylglycerols was generally similar to that of total lipids in which saturated, monounsaturated and polyunsaturated fatty acids (PUFA) were present in almost equal proportions. Each of the polar lipid classes had a specific fatty acid composition. With the exception of phosphatidylinositol (PI), in which 20∶4n−6 comprised 27.4% of the total fatty acids, 22∶6n−3 was the principal PUFA in all lipid classes. The proportion of 20∶5n−3 never exceeded 6.0% of the fatty acids in any lipid class. The predominant molecular species of PC were 16∶0/22∶6n−3 and 16∶0/18∶1, which accounted for 33.2 and 28.5%, respectively, of the total molecular species of this phospholipid. Phosphatidylethanolamine (PE) contained the highest level of di‐22∶6n−3 (13.0%) of any phospholipid. There was also 4.9% of this molecular species in phosphatidylserine (PS) and 4.1% in PC. In PE, the species 16∶0/22∶6, 18∶1/22∶6 and 18∶0/22∶6 totalled 45.1%, while in PS 18∶0/22∶6 accounted for 43.9% of the total molecular species. The most abundant molecular species of PI was 18∶0/20∶4n−6 (37.8%). The lipid composition of the pineal organ of trout, and particularly the molecular species composition of PI, is more similar to the composition of the retina than that of the brain.
Comparison of body weight and adipose tissue in male C57BI/6J mice fed diets with and withouttrans fatty acids
Authors: Atal Subodh , Zamowski Mary Jane , Cushman Samuel W. , Sampugna Joseph 
Published: November 2006

AbstractThe effect of a diet containingtrans‐fatty acids (tFA) on the fatty acid composition and fat accumulation in adipose tissue was investigated in mice. Male C57BI/6J mice were fed Control or Trans Diets that were similar, except that 50% of the 18∶1, which was allcis in the Control Diet, was replaced bytFA in the Trans Diet. At selected ages, body weight, epididymal fat pad weight, perirenal fat yield, adipose tissue cellularity and fatty acid composition were examined. Over the time period studied (2–24 mon), the proportion of 18∶0 and 16∶0 tended to decrease whilecis‐18∶1 levels increased. Compared to the Control Diet, the Trans Diet resulted in adipose tissue lipids with higher percentages of 14∶0 and 18∶2n−6 and lower percentages ofcis‐18∶1 and 20∶4n−6. In polar lipids,tFA replaced saturated fatty acids, whereastFA replacedcis‐18∶1 in the nonpolar lipids. Body weights at 16 and 24 mon of age and epididymal fat pad weights at 8–24 mon of age were lower in mice fed the Trans Diet as compared to those fed the Control Diet. At the ages studied, the Trans Diet also resulted in lower values for perirenal fat weights, triacylglycerol to polar lipid ratios, and adipose cell size. The data suggest that chronic consumption oftFA affects lipid metabolism and results in decreased fat accumulation in murine adipose tissue.
Liver Δ5 and Δ6 desaturase activity differs among laboratory rat strains
Authors: de Antueno Roberto J. , Elliot Michele , Horrobin David F. 
Published: November 2006

AbstractThis study was designed to examine the variations among rat strains in hepatic fatty acid desaturase activities and to determine the correlations between the activities of these enzymes and the levels of each microsomal fatty acid. Wistar rats from two different sources as well as Long‐Evans and Sprague‐Dawley rats were selected to assess, under standard and identical experimental conditions, the liver Δ5 and Δ6 desaturase activities. Both desaturase activities were significantly reduced by 56% in Sprague‐Dawley rats when compared to BB‐Wistar control rats, whereas intermediate reduced values were detected in Wistar (CR) and Long‐Evans strains. The activities of Δ5 and Δ6 desaturases were significantly and positively correlated with each other. However, no significant correlations were detected between either Δ5 or Δ6 desaturase activities and levels of any of their fatty acid substrates or any other of the major microsomal fatty acids. Fatty acid composition of microsomal total lipids showed strain dependency. A positive correlation was detected between the microsomal levels of the two major final products of both desaturases, namely 20∶4n−6 and 22∶6n−3. In general, the sum of n−3 or n−6 fatty acids but not the ratio of one to the other, varied among rat strains. The study demonstrated that Δ6 and Δ5 desaturase activities are strain‐related. The data also suggested that (i) the desaturation activity should be measured and not predicted from the fatty acid composition and (ii) different rat strains should be used for lipid metabolic studies before conclusions are drawn for rats in general.