bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ether glycerophospholipids of gills of two pacific crabs,Cancer antennarius andPortunus xantusi
Authors: Chapelle S. , Hakanson J. L. , Nevenzel J. C. , Benson A. A. 
Published: November 2006

AbstractPhospholipids and sterols constituted 70 and 20%, respectively, of the total lipids of the gills of two crabs,Cancer antennarius andPortunus xantusi. Phosphatidylcholine (46–55% of the total phospholipid phosphorous) and phosphatidylethanolamine (24–25%) were the principal phospholipids present. In both species 1′‐alkenyl glycerols were present in about 20% of the phospholipid molecules but were not detected in the neutral gill lipids. The total ether phospholipids ofC. antennarius gills contained 62% 1‐(1′‐alkenyl) groups, with the remainder probably being 1‐alkyl moieties. Total gill plasmalogen contents were in the range of 163–184 μmol/g lipid, 82–87% of which was in the phosphatidylethanolamine fraction in both crab species.
Free and esterified sterols of cotton buds and anthers
Authors: Lusby William R. , Oliver James E. , McKibben Gerald H. , Thompson Malcolm J. 
Published: November 2006

AbstractCapillary gas liquid chromatography analyses were conducted on free and esterified sterol fractions of cotton (Gossypium hirsutum cv. Stoneville 213) floral buds and anthers. The free sterols of both cotton buds and anthers consist mainly of the common plant sterols sitosterol, stigmasterol and 24ζ‐methylcholest‐5‐en‐3β‐ol. The composition of esterified sterols of cotton buds and anthers were similar, and consisted of pollinastanol, 31‐norcycloartanol, cycloartenol, 31‐norcycloartenol, 24‐dehydropolinastanol and sitosterol. Desmosterol was also present in both the free and esterified sterols of anthers. The identities of the sterols were confirmed by gas chromatography‐mass spectrometry analyses. Esterified sterols accounted for 46.7 and 88.7% of total sterols of cotton bud and anthers, respectively. The ratio of esterified sterol to free sterol per gram of tissue is about 8∶1 in anthers. The Δ5‐sterols of the esterified sterols of cotton buds and anthers account for only 17 and 9.2% of the total sterols, respectively.
The effects of fat‐free, saturated and polyunsaturated fat diets on rat liver and plasma lipids
Authors: Nelson Gary J. , Kelley Darshan S. , Schmidt Perla C. , Serrato Claire M. 
Published: November 2006

AbstractThe liver and plasma lipids and fatty acid composition of rats fed synthetic diets of differing fat type and content were studied. All animals were starved for 48 hr and then refed a high carbohydrate, fat‐free diet for 48 hr. They were then divided into three groups and fed for an additional 48 hrs the following: group 1, the fat‐free diet; group 2, a diet containing 44% of calories from corn oil; and group 3, a diet containing 44% calories from completely hydrogenated soybean oil. The total lipid concentration of the liver in the animals on the fat‐free diet was elevated at 72 and 96 hr. The addition of either saturated or unsaturated fat in the diet at 48 hr prevented this accumulation. The total phospholipid and cholesterol concentrations of the liver were relatively uninfluenced by any diet in this study. Plasma total fatty acid concentration was elevated at 72 hr in the animals on a fat‐free diet compared to those fed the stock diet, starved for 48 hr or fed the fat‐containing diets. By 96 hr, however plasma fatty acid concentrations in all groups were similar to those in animals fed only the stock diet. The release of de novo synthesized fatty acids into plasma from the liver was strongly inhibited by dietary fat, either saturated or polyunsaturated. With the fat‐free diet there was a significant increase in the saturated and monounsaturated fatty acids in both liver and plasma. The addition of corn oil to the diet facilitated a reversion of the fatty acid composition in liver and plasma to that found in the animals fed the stock diet ad libitum, but saturated fat did not. No effect of diet on the fatty acid composition of the red cells was observed during the course of this study. Exogenous saturated fatty acids, although similar chemically to the fatty acids synthesized by the liver, may have physiological actions that differ from endogenously synthesized fat.
The effect of mengovirus infection on lipid synthesis in cultured ehrlich ascites tumor cells
Authors: Schimmel Helmut , Traub Peter 
Published: November 2006

AbstractThe concept of generally increased lipid synthesis during the initial 2/3 of picornaviral infectious cycles, held by several authors, needs differentiation. In mengovirus‐infected Ehrlich ascites tumor cells, an increase in the rate of synthesis of phosphatidylcholine could be confirmed, but for phosphatidylethanolamine constant to decreasing rates of synthesis were found. Moreover, phosphatidylinositol was increasingly synthesized in the midst of the infectious cycle. The changes observed might have their functional expression in the proliferation of smooth cytoplasmic membrane systems that provide the structural framework for the replication of picornaviral RNA and virus assembly. The alterations in the labeling patterns of phosphatidylinositol, phosphatidylglycerol and diphosphatidylglycerol late in virus infection point to increased turnover of these compounds, possibly mediated by phospholipase D. The formation of lysophosphatidylcholine (cytolytic effect) and bis(monoacylglyceryl)phosphate in the final phase of the infectious cycle might be correlated with the liberation of lysosomal enzymes and the development of the cytopathic effect.
Oleic acid modulates the partitioning of cholesterol from micellar bile salt solution
Authors: Chijiiwa Kazuo 
Published: November 2006

AbstractThe effects of monounsaturated fatty acid (oleic acid) on cholesterol monomer activity and on the rate of cholesterol influx were studied in vitro. A polyethylene disc method was employed to determine cholesterol monomer activity in constant sodium taurocholate‐cholesterol micellar solution containing different oleic acid concentration levels at pH 5.5, 6.5 and 7.2. In addition, the effect of oleic acid on the rates of cholesterol influx was determined using an everted rat jejunal sac technique.At pH 5.5, increased oleic acid concentration from 5 to 10 mM resulted in significant decreased apparent cholesterol monomer activity (3.8±0.21 nmol/disc vs 1.0±0.08, P<0.001). At pH 6.5, apparent cholesterol monomer activity was 2.3±0.19 nmol/disc at 5 mM and 0.5±0.09 at 16 mM oleic acid level (P<0.001). Apparent monomer activity of cholesterol in micellar solutions at pH 7.2 used for the influx study at 5 and 15 mM oleic acid concentration level was 1.8±0.14 and 0.7±0.08 nmol/disc, respectively (P<0.001). Thus there was a significant decrease in cholesterol monomer activity by the addition of oleic acid at each pH. The rate of cholesterol influx across the brush border membrane of the rat jejunum at 5 and 15 mM oleic acid concentration level was 3.2±0.31 and 1.5±0.21 nmol/100 mg dry weight tissues/min, respectively (P<0.001).It is concluded that the addition of oleic acid decreases both monomer activity and the rate of influx of cholesterol from micellar solution. This effect is primarily attributable to the inhibition of the release of cholesterol monomers from the mixed micelle.
Bile lipid secretion in isolated perfused rat liver. A model for metabolic studies
Authors: Henry J. C. , Domingo N. , Chanussot F. , Lafont H. , Hauton J. C. , Cano J. P. 
Published: November 2006

AbstractIsolated perfused rat liver was used to study the effects of constant taurocholate perfusion, with or without the addition of phosphatidylcholine unilamellar vesicles, upon both the bile salt‐dependent and bile salt‐independent secretion of bile. Taurocholate introduction increased bile flow and normalized the bile lipid secretion by restoring the bile salt‐dependent secretion. At a flow rate of 30 ml/min, the liver was perfused by a single‐pass method. The perfusion medium contained 17.5 μM taurocholate with or without 5.83 μM phosphatidylcholine. In light of a recent quantitative dynamic concept on the interphase partition of lipids, it was calculated that more than99% of the taurocholate reaches the liver as monomers and/or dimers. It was also deduced that the lipids were secreted in bile as small discoidal lipoprotein structures rather than unilamellar lipoproteic vesicles. During the course of the experiments (2 hr), the excellent criteria of viability of this model make it highly suitable for the investigation of hepatic metabolism. Furthermore, the addition of phosphatidylcholine unilamellar vesicles to the perfusate consitutes a potential vector for various liposoluble molecular species.
Activities of liver mitochondrial and peroxisomal fatty acid oxidation enzymes in rats fedtrans fat
Authors: Ide Takashi , Watanabe Midori , Sugano Michihiro , Yamamoto Iwahiko 
Published: November 2006

AbstractThe effect oftrans fat on the activities of liver mitochondrial and peroxisomal fatty acid oxidation enzymes was examined in various strains of rats. When Wistar and Sprague‐Dawley rats were fed for 30 days diets containing either olive oil or partially hydrogenated corn oil as a source ofcis‐ortrans‐octadecenoate, respectively, the activities of various enzymes of mitochondrial and peroxisomal β‐oxidation measured withcis‐ andtrans‐9‐octadecenoic acid as substratese showed little dietary fatdependent change. In Fischer 344 rats, feedingtrans fat for 15 mo increased only moderately various enzymes of β‐oxidation except for carnitine acyltransferase. The rate of mitochondrial ketogenesis and the activity of carnitine acyltransferase measured withtrans‐9‐octadecenoic acid as a substrate were about half those with thecis‐counterpart. Peroxisomes oxidizedtrans‐9‐octadecenoyl‐CoA at a rate comparable to thecis‐counterpart. It was concluded from this study and previous ones that the difference in the geometry of dietary fatty acid had only a marginal effect in modulating the hepatic fatty acid oxidation system, in spite of marked differences in the metabolic behavior ofcis‐andtrans fatty acid in cell‐free preparations and perfused liver.
Effect of lecithin on the release of 5′‐nucleotidase from liver plasma membrane of rat by bile acids
Authors: Nokubo Munetaka 
Published: November 2006

AbstractBile acids solubilize proteins from liver plasma membrane both in vivo and in vitro. The ability to solubilize the proteins is dependent on the species of bile acid. In this paper, the effect of phospholipid on the solubilization of a membrane‐bound enzyme by bile acids was investigated in vitro. Taurocholate (TC) and tauroursodeoxycholate (TUDC) solubilized the enzyme, 5′‐nucleotidase, from the liver plasma membrane of the rat in a concentration‐dependent manner, although there was a great difference in their effect; at 40 mM, TC solubilized 55.4% of the original 5′‐nucleotidase activity of the membrane, but TUDC only 5.7%. While lecithin alone had no solubilizing effect, its addition to the bile acids provoked a 10‐fold increase in the solubilizing effect of TUDC, but virtually no change for TC, essentially equalizing the solubilizing effect of the two. Both TC‐rich and TUDC‐rich bile were obtained from rats infused with the respective bile acids via the jugular vein after their endogenous bile acid pool had been depleted. The solubilization effect of these biles was quite similar to the bile acid‐lecithin mixtures. These findings demonstrate that lecithin enhances the ability of the bile acids to solubilize the membrane protein and eliminates the difference in the two bile acid species in their solubilizing ability.
Asymmetric distribution of arachidonic and n−3 polyunsaturated fatty acids in rat liver microsomal membranes under a fat‐free diet
Authors: Iritani Nobuko , Mizoguchi Hisako , Kitaya Misao 
Published: November 2006

AbstractRats adapted to a corn oil or a fish oil diet were fed a fat‐free diet, and changes in phospholipid polyunsaturated fatty acids (PUFA) in the inner and outer leaflets of liver microsomal membranes were followed for 18 wk. In rats previously adapted to a corn oil diet, arachidonic acid in phosphatidylcholine and phosphatidylethanolamine in the inner and outer leaflets did not decrease quickly; rather, linoleic acid decreased more than arachidonic acid for the first three weeks of feeding the fat‐free diet. Even at 18 wk, 40–50% of the beginning arachidonic acid levels were still retained. In contrast, in rats previously adapted to a fish oil diet, the n−3 PUFA were quickly decreased by the fat‐free diet to only 10–30% at 18 wk. Due to the appearance and increase of n−9 eicosatrienoic acid in the replacement of the n−3 and n−6 PUFA, total PUFA did not decrease in the inner and outer phosphatidylcholine in either group, but decreased somewhat in the phosphatidylethanolamine due to the insufficient increase of the n−9. On the other hand, the overall degrees of unsaturation in phosphatidylcholine fatty acids were always higher in the outer than in the inner leaflets and were not altered by feeding the fat‐free diet even for 18 wk. Thus, the results appear to reveal the physiological importance of unsaturation ratio of fatty acids and the necessity of arachidonic acid in each membrane leaflet.
A micromethod for the estimation of blood dolichol
Authors: Morris George N. , Pullarkat Raju K. 
Published: November 2006

AbstractA micromethod for the estimation of dolichol in blood was developed using high performance liquid chromatography. This method can be applied to whole blood or plasma. With detector sensitivity set at 0.005 Absorbance Unit Full Scale, samples as little as 50 μl are sufficient to carry out the determination. Blood samples from the tail vein of inbred strains of C57 BL/6 NNia‐1 mice 3,6, 12 and 24 mo of age were examined. Blood dolichol levels decreased with age from 163.3 ng/ml at 6 mo to 110.1 ng/ml at 24 mo. The major dolichol homologs were C‐85 (10.4%), C‐90 (41.6%), C‐95 (38.0%) and C‐100 (8.1%).
Lymphatic absorption of nonvolatile oxidation products of heated oils in the rat
Authors: Combe N. , Constantin M. J. , Entressangles B. 
Published: November 2006

AbstractThe lymphatic absorption of nonvolatile oxidation products (NVOP) formed during heating of fats was studied. Heated colza or soybean oils or synthetic triglycerides containing a definite aromatic or alicyclic fatty acid were fed to thoracic duct‐cannulated rats. Tritium‐labeled triolein was added to each dietary fat, as an internal standard, in order to calculate the percentage of lymphatic absorption of the ingested NVOP. Results show that 4% of the total polymeric acids, 53% of the total oxidized monomeric acids and 96% of the total cyclic monomeric acids were recovered in the lymphatic lipids. Gas liquid and quantitative thin layer chromatography of these 3 classes indicated that, within a NVOP class, the various constituents did not present the same absorption rate. The lymphatic absorptions of individual oxidized monomers were between 25 and 93%. Concerning the polymer fraction, the lymphatic recoveries were 1% (nonpolar dimers), 6.8% (polar dimers) and 12% (polar oligomers). Aromatic acids were absorbed to a lesser degree (50–60%) than cyclohexenic acids (91–98%).
Antilipidemic activity of 4‐oxo‐functionalized ethyl 6‐chlorochroman‐2‐carboxylate analogs and a related tricyclic lactone in three rat models
Authors: Cavestri R. C. , Minatelli J. A. , Baldwin J. R. , Loh W. , Feller D. R. , Newman H. A. I. , Sober C. L. , Witiak D. T. 
Published: November 2006

AbstractThe synthesis of ethylcis‐6‐chloro‐4‐hydroxychroman‐2‐carboxylate (IV) and 6‐chloro‐4‐hydroxychroman‐2‐carboxylic acid lactone (V) are reported. The antilipidemic properties of these compounds in 3 rat models were compared to the activity obtained for the previously synthesized related analogs ethyl 6‐chlorochroman‐2‐carboxylate (II), ethyl 6‐chlorochromanone‐2‐carboxylate (III) and clofibrate (I). The biologically most interesting analog, ethyl 6‐chlorochroman‐2‐carboxylate (II) like clofibrate (I), was an effective antitriglyceridemic and anticholesterolemic agent in Triton WR‐1339 hyperlipidemic rats, sucrose‐fed hyperlipidemic rats and chow‐fed normolipemic rats. Ethyl 6‐chlorochromanone‐2‐carboxylate (III) was found to be active only after 7 days of administration to sucrosefed rats. In sucrose‐fed, male Sprague‐Dawley rats, the comparative effects of these analogs on various hepatic drug parameters also were carried out. Consistent with previous findings, results obtained with these compounds provide evidence showing that changes in hepatic HMG‐CoA reductase activity bear no relationship to serum cholesterol lowering in the sucrose‐fed model.
The enzymic synthesis of GM1b: rat‐brain CMP‐N‐Acetylneuraminic acid: Asialo‐GM1 sialyltransferase
Authors: Yip M. C. M. , Nguyen N. T. 
Published: November 2006

AbstractAn enzyme which catalyzes the transfer of N‐acetylneuraminic acid (NeuNAc) to a tetrahexosylceramide (asialo‐GM1) in young rat brain is described. The enzymic product is a new monsialoganglioside containing a neuraminidase‐labile neuraminic acid, GM1b. The activity of this sialyltransferase is higher in fetal and young rat brains. The enzyme exhibits a pH optimum of 6.5 in cacodylate buffer. The incorporation of radioactivity into GM1b is stimulated in the presence of asialo‐GM1 and CMP‐NeuNAc and is dependent, on the quantity added. The detergent mixture, Tween 80 and CF54, is required for optimal activity. Recent demonstration of the natural occurrence of GM1b in the free cell types of rat ascites hepatoma cells suggests a functional importance of this CMP‐NeuNAc:asialo‐GM1 sialyltransferase in the in vivo formation of this novel monosialoganglioside.
Fatty acid composition of individual plasma steryl esters in phytosterolemia and xanthomatosis
Authors: Kuksis A. , Myher J. J. , Marai L. , Little J. A. , McArthur R. G. , Roncari D. A. K. 
Published: November 2006

AbstractThe bulk of the plasma plant sterol in phytosterolemia occurs in the esterified form and is carried mostly in the low and high density lipoproteins. We have determined the fatty acid composition of the individual plasma steryl esters from a newly discovered subject with phytosterolemia and xanthomatosis. For this purpose the intact steryl esters were subject to high temperature gas liquid chromatography (GLC) on a polar capillary column, which separated the major esters on the basis of molecular weight and degree of unsaturation of the fatty acids. The saturated and unsaturated sterols esterified to saturated, monoenoic, dienoic and tetraenoic fatty acids were identified by GLC analysis of the sterol moieties of the corresponding AgNO3‐TLC fractions of the steryl esters. The GLC results were confirmed by reversed phase high performance liquid chromatography combined with mass spectrometry via direct liquid inlet interface. It was found that, in general, each fatty acid was esterified to the same complement of sterols, and that the esterified sterols possessed a composition comparable to that of the free plasma sterols, which was comprised of about 75% cholesterol, 6% campesterol, 4% 22,23‐dihydrobrassicasterol and 15% β‐sitosterol. The fatty acid composition of the steryl esters differed from that of the 2‐position of the plasma phosphatidylcholines, which contained significantly less palmitic and oleic and more linoleic acid. On the basis of these results and a review of the literature it is suggested that the plasma cholesteryl and plant steryl esters in phytosterolemia originate from both synthesis in plasma via the lecithin‐cholesterol acyltransferase and synthesis in tissues via the acylCoA‐cholesterol acyltransferase.
cis‐Vaccenic acid in mango pulp lipids
Authors: Shibahara Akira , Yamamoto Kohei , Nakayama Takao , Kajimoto Goro 
Published: November 2006

AbstractA peak corresponding to a methyl octadecenoate other than oleate has been detected on the capillary gas chromatogram of the methyl esters of mango pulp fatty acids. This octadecenoate was isolated by silica gel and argentation column chromatography, high performance liquid chromatography and argentation thin layer chromatography, and then analyzed by infrared, nuclear magnetic resonance and gas chromatography‐mass spectrometry, chromatographic separations and oxidative degradation. These analytical data proved that the octadecenoic acid wascis‐vaccenic acid (cis‐11‐octadecenoic acid). The concentration of this acid in total octadecenoic acids ranged from 35% to 50% in the pulp of mangoes from Fiji, Mexico, the Philippines and Taiwan.cis‐Vaccenic acid was revealed to be one of the major component fatty acids of non‐polar lipids (mainly triacylglycerols), glycolipids and phospholipids in mango pulp. The glycolipids containedcis‐vaccenic acid (ca. 20%) in higher concentration than oleic acid (ca. 15%). A trace amount ofcis‐vaccenic acid (0.5%) was detected in the total lipids of mango seeds. Profile of fatty acid composition of mango pulp lipids (0.2–0.3 wt% of wet pulp) was characterized by the presence of n−7 acid isomers,cis‐vaccenic acid and palmitoleic acid, and unusual mono‐ and dienoic positional isomers.
Influence of dietary fat on metabolism of (14‐14C)erucic acid in the perfused rat liver. Distribution of metabolites in lipid classes
Authors: Hølmer Gunhild , Rønneberg Ragnhild 
Published: November 2006

AbstractTwo groups of rats were fed diets containing 20% by weight of either partially hydrogenated marine oil supplemented with sunflower seed oil (PHMO) or palm oil (PO) for 8 wk. Using a liver perfusion system, the effect of dietary long chain monoenoic fatty acids on the uptake and metabolism of [14‐14C]erucic acid was studied. The perfusion times were 15 and 60 min, respectively. The two groups showed equal ability for erucic acid uptake in the liver but differed in the channeling of the fatty acids into various metabolic pathways. A higher metabolic turnover of 22∶1 in the PHMO livers relative to the PO livers was demonstrated by an increased recovery of total [14C]labeling in the triglyceride (TG) and phospholipid (PL) fractions, already evident after 15 min of perfusion. The chainshortening capacity was highest in the PHMO group, reflected by a higher [14C]18∶1 incorporation in both TG and PL, and increasing from 15 to 60 min of perfusion. The amount of [14C]18∶1 found in PL and TG after 60 min of perfusion of livers from rats fed PO corresponded to that shown for the PHMO group after 15 min. The PL demonstrated a discrimination against 22∶1 compared to TG, and, when available, 18∶1 was highly preferred for PL‐synthesis.The total fatty acid distribution in the TG, as determined by gas liquid chromatography (GLC), reflected the composition of the dietary fats. In the total liver PL, 22∶1 and 20∶1 were present in negligible amounts, although the PHMO diet contained 12–13% of both 22∶1 and 20∶1. In the free fatty acid fraction (FFA), the major part of the radioactivity (≈80%) was [14‐14C]erucic acid, and only small amounts of [14C]18∶1(<2%) were presents, even after 60 min of perfusion. The shortened‐chain 18∶1 was readily removed from the FFA pool and preferentially used for lipid esterification.