bluuebunny/crossref_metadata_2025_split huggingface dataset:
The incorporation of fatty acids of different chain length into liver and biliary lipids in the perfused rat liver
Authors: Rubin Moshe , Pakula Ronit , Gilat Tuvia , Tietz Alisa 
Published: November 2006

AbstractIn an attempt to correlate the incorporation of fatty acids (FA) of different chain length into liver and biliary lipids’ isolated rat livers were perfused for 2 h with Krebs‐Ringer bicarbonate containing 1% albumin and 10 μmol of [1‐14C]‐labeled FA: C2’ C8’ C10’ C12’ C16’ and C18∶1. One to 1.36 μmol of medium‐chain fatty acids (MCFA’ C8’ C10’ and C12) and 6.6 μmol of long‐chain FA (LCFA) were incorporated into liver lipids’ 40% of the latter into phosphatidylcholine (PC). 14C‐acetate (13 nmol) was incorporated into biliary cholesterol; 14C‐MCFA contributed only 3.2–5 nmol; LCFA did not lead to newly synthesized cholesterol. Newly synthesized liver PC (2.75 to 3.25%) and newly synthesized liver cholesterol (6.5 to 10%) were secreted into bile. The specific radioactivity of biliary PC after infusion of all‐saturated FA was 3.8–6.8 times higher than that of liver PC; for C18∶1 it was only 1.7‐fold. The specific radioactivity of biliary cholesterol’ as compared to liver cholesterol’ was 12 times higher for C2 and five times higher for MCFA. This indicates that a considerable proportion of the newly synthesized lipids was secreted into bile prior to significant mixing with preexisting liver PC and cholesterol pools. liver PC contained 8% of unchanged 14C−C12; while 14C−C10 was not detected. Biliary PC’ in contrast’ contained 18% of unchanged 14C−C12 and 3% 14C−C10. These results suggest that after prolonged infusion of medium‐chain triacylglycerols/longchain triacylglycerols to patients’ biliary PC may become enriched with MCFA. In addition’ the oxidation of these FA may provide C‐2 units which increase cholesterol synthesis.
The metabolism of native and randomized butterfat chylomicrons in the rat is similar
Authors: Hodge Jason , Li Duo , Redgrave Trevor G. , Sinclair Andrew J. 
Published: November 2006

AbstractReportedly’ randomly rearranging the position of fatty acids (FA) in butterfat triacylglycerol (TAG) by interesterification’ thereby lowering the proportion of saturated FA in the sn‐2 position’ reduces its hypercholesterolemic and hypertriglyceridemic properties when fed to humans. The aim of this work was to determine if these reductions in plasma cholesterol and TAG could be explained by an improved rate of clearance from the plasma of chylomicrons composed of randomized butterfat’ using a rat model. Acute chylomicron clearance studies demonstrated no differences in fractional clearance rates of cholesteryl esters and TAG from the plasma of rats infused with chylomicrons produced from gastric feeding of either native (NBF) or randomized (RBF) butterfat. Although there was a 14% decrease in the level of saturated FA occupying the sn‐2 position of TAG in RBF compared with NBF’ this difference became negligible (∼5%)’ following digestion of the fat and subsequent repackaging of TAG into chylomicrons. These observations suggest that the previously observed reduction in hypercholesterolemic properties of randomized butterfat in rat is unlikely to be explained by improved clearance of chylomicron TAG.
Cholesterol synthesis and degradation in normal rats fed a cholesterol‐free diet with excess cystine
Authors: Aoyama Yoritaka , Amano Nobuyuki , Yoshida Akira 
Published: November 2006

AbstractFeeding a diet with excess cystine to rats resulted in hypercholesterolemia. To understand the mechanism of the hypercholesterolemia’ cholesterol synthesis and degradation’ bile acid content of bile’ and fecal steroids were determined. The in vivo incorporation of tritiated water into hepatic cholesterol’ and activity of hepatic 3‐hydroxy‐3‐methylglutaryl‐CoA reductase in rats fed a high‐cystine diet were significantly higher than those in rats fed a control diet. The activity of hepatic cholesterol 7α‐hydroxylase was similar between two groups. Little effect of cystine supplementation was found on fecal sterol excretion although there were some changes in biliary excretion of cholic acid derivatives. These results indicate that hypercholesterolemia caused by feeding of a high‐cystine diet may be due to the stimulation of hepatic cholesterol synthesis.
Cell proliferation’ differentiation’ and apoptosis are modified by n−3 polyunsaturated fatty acids in normal colonic mucosa
Authors: Calviello Gabriella , Palozza Paola , Maggiano Nicola , Piccioni Elisabetta , Franceschelli Piergiorgio , Frattucci Andrea , Di Nicuolo Fiorella , Bartoh Gianna Maria 
Published: November 2006

AbstractSupplementation with low doses of eicosapentaenoic (EPA) or docosahexaenoic (DHA) acid was used here to investigate changes in epithelial proliferation’ differentiation’ and apoptosis in normal rat colonic mucosa. ACI/T rats received by oral administration low doses of purified EPA or DHA ethyl esters (1g/kg body weight) and colonic mucosa was analyzed for cell proliferation’ differentiation’ and apoptosis. n−3 Polyunsaturated fatty acid incorporation into membrane phospholipids was investigated as reflections of fatty acid metabolism. Both EPA and DHA suppressed colonocyle proliferation and increased the numbers of differentiating and apoptotic cells without modification of the crypt morphology and the number of cells per crypt columns. A significant incorporation of the supplemented fatty acids into total phospholipids was observed. This enrichment was accompanied by a decreased content in arachidonic acid. The observation that EPA and DHA do not alter crypt morphology although they modify cell turnover in normal colonic mucosa suggests a possible use of these fatty acids as dietary chemopreventive agents.
Enhancement of sterol synthesis by the monoterpene perillyl alcohol is unaffected by competitive 3‐hydroxy‐3‐methylglutaryl‐CoA reductase inhibition
Authors: Cerda sonia R. , Wilkinson John , Branch Steven K. , Broitman Selwyn A. 
Published: November 2006

AbstractMonoterpenes such as limonene and perillyl alcohol (PA) are currently under investigation for their chemotherapeutic properties which have been tied to their ability to affect protein isoprenylation. Because PA affects the synthesis of isoprenoids’ such as ubiquinone’ and cholesterol is the end product of the synthetic pathway from which this isoprenoid pathway branches’ we investigated the effects of this compound upon cholesterol metabolism in the colonic adenocarcinoma cell line SW480. PA (1 mM) inhibited incorporation of 14C‐mevalonate into 21–26 kDa proteins by 25% in SW480 cells. Cholesterol (CH) biosynthesis was assessed by measuring the incorporation of 14C‐acetate and 14C‐mevalonate into 27‐carbon‐sterols. Cells treated with PA (1 mM) exhibited a fourfold increase in the incorporation of 14C‐acetate but not 14C‐mevalonate into cholesterol. Mevinolin (lovastatin)’ an inhibitor of 3‐hydroxy‐3‐methylglutaryl‐CoA (HMG‐CoA) reductase’ at 2 μM concentration’ inhibited CH synthesis from 14C‐acetate by 80%. Surprisingly’ concurrent addition of mevinolin and PA did not significantly alter the stimulatory effects of PA. As observed differences in 14C‐acetate and 14C‐mevalonate precursor labeling could indicate PA affects early pathway events’ the effects of this monoterpene on HMG‐CoA reductase activity were evaluated. Unexpectedly’ 1 mM PA did not stimulate activity of this enzyme. Consistent with its action as a reversibly bound inhibitor’ in washed microsomes’ 2 μM mevinolin pretreatment increased reductase protein expression causing a 12.7 (±2.4)‐fold compensatory HMG‐CoA reductase activity increase; concurrent treatment with 1 mM PA attenuated this to a 5.3 (±0.03)‐fold increase. Gas chromatographic analysis confirmed CH was the major lipid present in the measured thin‐layer chromatography spot. Since 14C‐acetate incorporation into free fatty acid and phospholipid pools was not significantly affected by PA treatment’ nonspecific changes in whole acetate pool sizes were not indicated. Because increases in endogenous CH synthesis should result in compensatory changes in exogenous sterol utilization’ the effects of PA upon low density lipoprotein (LDL) receptor activity were evaluated. Consistent with the observed increases in CH synthesis’ 1 mM PA decreased 125I‐LDL internalization to 50% of the fetal bovine serum control; concurrent addition of 2 μM mevinolin attenuated this effect to a reduction of 80% of the control value. Data suggest that in certain colonic tumor cells PA strongly affects cholesterol metabolism via a mechanism of action that is insensitive to the HMG‐CoA reductase inhibitor mevinolin.
The metabolism and distribution of sesame lignans (sesamin and episesamin) in rats
Authors: Umeda‐Sawada Rumi , Ogawa Megumi , Igarashi Osamu 
Published: November 2006

AbstractIn this study’ we examined the distribution and metabolism of refined sesame oil lignans (sesamin and episesamin) in rat. For 8 wk rats were fed the diet including 0.5% (w/w) sesame lignans (sesamin and episesamin) with 5% (w/w) corn oil or eicosapentaenoic acid (EPA)‐rich oil. The concentrations of sesamin and episesamin in rat liver after their administration for 8 wk were very low; both of them were less than 0.5 μg/g liver. These were observed in both oil groups although the fatty acid compositions of dietary oils were completely different. No significant difference existed in lymphatic absorption between sesamin and episesamin. To investigate the distribution of sesamin and episesamin in rats’ the concentrations of sesamin and episesamin were determined in tissues and serum within 24h after administration to rats. Sesamin and episesamin may be’ at first’ incorporated into the liver and then transported to the other tissues (lung’ heart’ kidney’ and brain). They are lost from the body within 24h after administration. There was no significant difference in lymphatic absorption between sesamin and episesamin’ but the amount of sesamin was significantly lower than that of episesamin in all tissues and serum. These results suggest that sesamin is absorbed in lymph the same as episesamin’ but that sesamin is subsequently metabolized faster by the liver.
Seasonal variation in the fatty acid composition and quality of sardine oil from sardinops sagax caeruleus of the gulf of California
Authors: Gámez‐Meza N. , Higuera‐Ciapara I. , Calderon de la Barca A. M. , Vázquez‐Moreno L. , Noriega‐Rodríguez J. , Angulo‐Guerrero O. 
Published: November 2006

AbstractOne of the few sources of long‐chain n‐3 polyun‐saturated fatty acids is fish oil’ but considerable variation may exist according to species and season. In this study’ the fatty acid profiles of sardine oils from Sardinops sagax caeruleus of the Gulf of California’ Mexico’ were evaluated in three seasonal catch periods. Oil quality was also evaluated by peroxide and free acid values. The most abundant fatty acids found in the oils were palmitic acid (19.3%)’ oleic acid (14.3%)’ eicosapentaenoic acid (EPA’ 20.4%)’ and docosahexaenoic acid (DHA’ 12.2%). There was no significant difference in the composition and quality among the six reduction plants where the samples were obtained. However’ a significant difference in the proportion of EPA and DHA in one of the catch seasons analyzed was observed.
Specific modifications of phosphatidylinositol and nonesterified fatty acid fractions in cultured porcine cardiomyocytes supplemented with n‐3 polyunsaturated fatty acids
Authors: Nair Sudheera S. D. , Leitch James , Garg Manohar L. 
Published: November 2006

AbstractMechanisms for the antiarrhythmic effect of n−3 polyunsaturated fatty acids (PUFA) are currently being investigated using isolated cardiac myocytes. It is still not known whether the incorporation of n−3 PUFA into membrane phospholipids is a prerequisite for its protective action or if n−3 PUFA exert antiarrhythmic effects in their nonesterified form as demonstrated by recent studies. Adult porcine cardiomyocytes were grown in media supplemented with arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). After 24 h, analysis of total lipids showed that the myocytes were enriched with the respective fatty acids compared to control cells. Large proportions of all three fatty acids supplemented (69% AA, 72% DHA, and 66% EPA) remained unesterified. Fatty acid analysis of total phospholipids (PL) revealed that the incorporation of EPA and DHA, though small, was significantly different (P<0.05) from that of the control cells. The PL fraction was further separated into phosphatidylinositol (Pl), phosphatidylethanolamine, phosphatidylcholine, and phosphatidylserine to study the pattern of incorporation of the fatty acids in these fractions. It became apparent that EPA and DHA were selectively incorporated into the Pl fraction. This study demonstrates that in adult porcine cardiomyocytes, the n−3 PUFA supplementation selectively modulates two important lipid fractions, nonesterified fatty acid and Pl, which were implicated in the mechanisms of prevention of cardiac arrhythmias.
Dose‐dependent inhibition of cell proliferation induced by lipid peroxidation products in rat hepatoma cells after enrichment with arachidonic acid
Authors: Muzio Giuliana , Salvo Raffaella A. , Trombetta Antonella , Autelli Riccardo , Maggiora Marina , Terreno Mario , Dianzani Mario U. , Canuto Rosa A. 
Published: November 2006

AbstractPolyunsaturated fatty acids (PUFA) are important constituents of membrane phospholipids, whose levels are decreased in some tumor cells. This deficiency may cause alterations in signal transduction and an interruption of normal cellular events. The enrichment of tumor cells with PUFA may stimulate or inhibit tumor growth, probably depending on the type of PUFA and the cellular concentration of aldehydes derived from restored lipid peroxidation. We examined the effect of several doses of prooxidant on the growth of hepatoma cells with different aldehyde dehydrogenase activities, enriched with arachidonic acid. Two doses of prooxidant were sufficient to reduce growth of hepatoma cells with low aldehyde dehydrogenase activity, whereas three doses were necessary for those with high enzyme activity. In both cases, lipid peroxidation products blocked the cells in the S phase.
Ethanol‐extracted soy protein isolate results in elevation of serum cholesterol in exogenously hypercholesterolemic rats
Authors: Ni Weihua , Yoshida Susumu , Tsuda Yasuyuki , Nagao Koji , Sato Masao , Imaizumi Katsumi 
Published: November 2006

AbstractSoy protein preparations were reported to have hypocholesterolemic actions in experimental animals and humans, while the active components and the mechanism by which this occurs are not clarified yet. The objective of this study is to address these issues by using exogenously hypercholesterolemic rats which are susceptible to dietary cholesterol. Two groups of five rats (male, 12‐wk‐old) were fed on AIN 93G‐based diet with soy protein isolate (SPI) or ethanol‐extracted SPI (EE‐SPI) for 2 wk. EE‐SPI was prepared by ethanol extraction to remove isoflavones and other components. Concentrations of serum and liver total cholesterol were lower in rats fed SPI than in those fed EE‐SPI. The abundances of mRNA for 7α‐hydroxylase and low density lipoprotein receptor in the liver were lower in EE‐SPI group than those in SPI group. These results suggest that the ethanol extract from SPI has a factor(s) to alleviate hypercholesterolemia by increasing the removal of cholesterol from serum through the receptor pathway and then from liver through enhancement of bile acid synthesis.
Absorption in rats of rapeseed, soybean, and sunflower oils before and following moderate heating
Authors: Porsgaard Trine , Zhang Hong , Nielsen Robert G. , Høy Carl‐Erik 
Published: November 2006

AbstractRapeseed, soybean, and sunflower oil were heated for 15 min in a 5‐mm oil layer in a pan at 180°C. The fatty acid composition was almost unaffected by heating, while the polymer content rose slightly and the tocopherol content decreased, except in soybean oil. The absorption of oils before and after heating was investigated in lymph‐cannulated rats. Oils were administered as emulsions through a gastrostomy tube and lymph was collected during the next 24 h. The highest accumulated lymphatic transport of total fatty acids was observed after administration of rapeseed oil, and the lowest after heated sunflower oil. The accumulated transport was similar for all unheated oils. The transport of fatty acids was significantly lower in rats receiving heated oil compared to those receiving the corresponding unheated oil. Small increases in polymers may have contributed to the decreased lymphatic transport of oil following heating, although this probably does not fully explain the effect. The absorption of sunflower oil was more affected by heating than the absorption of soybean or rapeseed oil. Furthermore, the largest decrease in total activity of tocopherols following heating was observed in sunflower oil. Overall, these results demonstrate that the absorption of vegetable oils is affected by moderate heating.
Fatty acid composition of brain glycerophospholipids in peroxisomal disorders
Authors: Martinez Manuela , Mougan Isabel 
Published: November 2006

AbstractThis paper shows for the first time the differential fatty acid composition of ethanolamine plasmalogens (EP) and phosphatidylethanolamine (PE) in the brains of 12 patients with disorders of peroxisomal biogenesis and compares the results to normal values for the age. Other important glycerophospholipids (GPL), such as phosphatidylserine (PS) and phosphatidylcholine (PC), are also included in this study. GPL were separated by two‐dimensional thin‐layer chromatography, and their fatty acid composition was determined by capillary column gas‐liquid chromatography. Total brain GPL were slightly decreased in peroxisomal disorders (27.98±2.95 μmol/g in the patients against 34.5±6.21 μmol/g in age‐matched controls, P=0.005), and the distribution of the different GPL classes was much altered. In confirmation of known data, EP were very much decreased (2.18±1.3 μmol/g in the patients against 6.9±2.3 μmol/g in controls) at the expense of PE, which was increased (8.58±2.17 μmol/g in the patients against 5.97±0.58 μmol/g in controls, P<0.005). PS and PC were both significantly decreased (P=0.0001 and P=0.037, respectively). The polyunsaturated fatty acid (PUFA) composition of all the GPL fractions was markedly abnormal. In absolute terms, docosahexaenoic acid (22∶6n−3) was drastically decreased in all GPL classes (always at the P<0.0001 level) while arachidonic acid (20∶4n−6) was increased in PE and PS (P<0.001 in both cases). In the alkenyl acyl form, EP, 22∶6n−3, and 20∶4n−6 were both very significantly decreased (P<0.0001), although the former was always the most affected. The myelin PUFA adrenic acid (22∶4n−6) was decreased in EP (P<0.0001) and slightly increased in PS (P<0.05). The changes found confirm that 22∶6n−3 deficiency is a predominant defect in the brain in peroxisomal disorders.
Recognition and quantitation of cis‐vaccenic and eicosenoic fatty acids in olive oils by 13C nuclear magnetic resonance spectroscopy
Authors: Scano P. , Casu M. , Lai A. , Saba G. , Dessi M. A. , Deiana M. , Corongiu F. P. , Bandino G. 
Published: November 2006

AbstractThe presence of 11‐cis monoenoic fatty acids was detected in olive oil samples by means of 13C nuclear magnetic resonance spectroscopy, and the positional isomery on the glycerol backbone was derived. The 11‐cis vaccenic and eicosenoic fatty acid resonances were recognized and the amounts of the fatty acids quantified. For comparison purposes, a quantitative analysis was also made by gas chromatography.
Olestra formulation and the gastrointestinal tract
Authors: Jandacek Ronald J. , Kester Jeffrey J. , Papa A. J. , Wehmeier Thomas J. , Lin Peter Y. T. 
Published: November 2006

AbstractOlestra is a mixture of compounds comprising sucrose esterified with 6–8 long‐chain fatty acids. It is not hydrolyzed by pancreatic lipase and as a result is not absorbed from the small intestine. Olestra in general has physical properties similar to those of a triacylglycerol with the same fatty acid composition. Foods made with olestra are virtually identical in taste and texture to those made with typical triacylglycerols. Olestra consumption does not generate hydrolytic products in the small intestine and, therefore, does not generate some of the signals that alter motility in the gastrointestinal tract. A reduction in gastroesophageal reflux with olestra, in contrast to triacylglycerols, is consistent with a lack of effect on stomach emptying. Unlike triacylglycerols that are absorbed in the proximal small intestine, olestra is distributed throughout the small intestine during transit and passes into the colon. In the colon, olestra's effects depend on its physical properties. Liquid nondigestible lipids result in separation of oil from the fecal matrix. Olestra formulations made with specific fatty acid compositions, particularly those containing a solid sucrose polyester component including behenic acid, possess appropriate rheology to hinder separation of oil from the rest of the fecal matrix, thereby reducing gastrointestinal symptoms.
Effect of dietary docosahexaenoic acid on desaturation and uptake in vivo of isotope‐labeled oleic, linoleic, and linolenic acids by male subjects
Authors: Emken E. A. , Adlof R. O. , Duval S. M. , Nelson G. J. 
Published: November 2006

AbstractThe effect of dietary docosahexaenoic acid (22∶6n−3, DHA) on the metabolism of oleic, linoleic, and linolenic acids was investigated in male subjects (n=6) confined to a metabolic unit and fed diets containing 6.5 or <0.1 g/d of DHA for 90 d. At the end of the diet period, the subjects were fed a mixture of deuterated triglycerides containing 18∶1n−9[d6], 18∶2n−6[d2], and 18∶3n−3[d4]. Blood samples were drawn at 0, 2, 4, 6, 8, 12, 24, 48, and 72 h. Methyl esters of plasma total lipids, triglycerides, phospholipids, and cholesterol esters were analyzed by gas chromatography‐mass spectrometry. Chylomicron triglyceride results show that the deuterated fatty acids were equally well absorbed and diet did not influence absorption. Compared to the low‐DHA diet (LO‐DHA), clearance of the labeled fatty acids from chylomicron triglycerides was modestly higher for subjects fed the high DHA diet (HI‐DHA). DHA supplementation significantly reduced the concentrations of most n‐6[d2] and n‐3[d4] long‐chain fatty acid (LCFA) metabolites in plasma lipids. Accumulation of 20∶5n−3[d4] and 22∶6n−3[d4] was depressed by 76 and 88%, respectively. Accumulations of 20∶3n−6[d2] and 20∶4n−6[d2] were both decreased by 72%. No effect of diet was observed on acyltransferase selectivity or on uptake and clearance of 18∶1n−9[d6], 18∶2n−6[d2], and 18∶3n−3[d4]. The results indicate that accumulation of n−3 LCFA metabolites synthesized from 18∶3n−3 in typical U.S. diets would be reduced from about 120 to 30 mg/d by supplementation with 6.5 g/d of DHA. Accumulation of n−6 LCFA metabolites synthesized from 18∶2n−6 in U.S. diets is estimated to be reduced from about 800 to 180 mg/d. This decrease is two to three times the amount of n−6 LCFA in a typical U.S. diet. These results support the hypothesis that health benefits associated with DHA supplementation are the combined result of reduced accretion of n−6 LCFA metabolites and an increase in n−3 LCFA levels in tissue lipids.