bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of triton WR 1339 and orotic acid on lipid metabolism in rats
Authors: Takeuchi Nozomu , Murase Mitsuharu , Nomura Yasuharu , Takase Haruto , Uchida Kiyohisa 
Published: November 2006

AbstractIn order to investigate the effect of hepatic cholesterol flux on biliary bile acids, Triton WR 1339 and orotic acid were administered to rats, and the biliary cholesterol, phospholipids and bile acids were analyzed together with serum lipoproteins and hepatic lipids. Triton, which raised serum very low density lipoprotein and lipid levels and decreased serum high density lipoprotein liver lipid levels, increase the biliary cholic acid group/chenodeoxycholic acid group ratio (CA/CDCA) in the bile without affecting the total amount of bile acids and the other biliary lipids. Orotic acid, which decreased serum lipid and lipoprotein concentrations and increased liver lipid levels, increased the biliary excretion of cholesterol and phospholipids, but produced no significant change in the total amount of bile acids and in the CA/CDCA ratio in bile.
Formation of diacyl and alkylacyl glycerophosphocholine in rabbit alveolar macrophages
Authors: Sugiura Takayuki , Sekiguchi Nobuyuki , Nakagawa Yasuhito , Waku Keizo 
Published: November 2006

AbstractThe incorporation of various labeled precursors into alkenylacyl, alkylacyl and diacyl phospholipids in rabbit alveolar macrophages was studied. The incorporation rates of the individual precursors were shown to be quite different among the three subclasses of phospholipids. [3H] Glycerol, [14C]16∶0, [14C]18∶1, [14C]18∶2 and [32P]‐orthophosphate were preferentially incorporated into choline glycerophospholipids (CGP), especially into diacyl glycerophosphocholine (GPC), indicating that the de novo synthesis of diacyl GPC is extremely high. Considerable portions of the radioactiveties of [14C]16∶0, [14C]18∶1, [14C]18∶2 and [32P] orthophosphate were also found in alkylacyl GPC, the incorporation being higher than or comparable to that in the case of diacyl glycerophosphoethanolamine (GPE). We then examined the activities of cholinephosphotransferase and ethanolaminephosphotransferase, and found that the activity of cholinephosphotransferase was remarkably high in macrophage microsomes compared with that in microsomes from several other tissues. This suggests that diradylglycerols were preferentially utilized by cholinephosphotransferase, which is consistent with the results obtained for intact cells. We confirmed that a considerably higher amount of diacyl GPC as well as alkylacyl GPC was formed through this enzyme reaction with macrophage microsomes than with brain microsomes. The high formation of alkylacyl GPC could be responsible, at least in part, for the accumulation of this unique ether phospholipid, a stored precursor form of plateletactivating factor in macrophages.
Effects of parenteral nutrition with high doses of linoleate on the developing human liver and brain
Authors: Martinez Manuela , Ballabriga Angel 
Published: November 2006

AbstractThe developmental changes in the fatty acid composition of ethanolamine phosphoglycerides (EPG) and choline phosphoglycerides (CPG) were studied in the liver and brain of 18 newborn infants with gestational ages ranging from 20 to 44 wk. A small group of five newborns receiving total parenteral nutrition (TPN) with high doses of linoleic acid (18∶2ω6) was also studied and compared to controls of the same gestational age to look for effects on the developmental fatty acid patterns of liver and brain EPG and CPG. TPN with Intralipid 20% was given for 4–12 days, the total fat intake being 14.7–90 g (mean ±S.D.=47.1±29.8 g). The main developmental changes in the liver and brain of the control group were an increase in 22∶6ω3 (docosahexaenoic acid) at the end of gestation and a linear decrease in 20∶4ω6 (arachidonic acid) and 18∶1ω9 (oleic acid) in EPG and CPG. A very good correlation in the percent values of these fatty acids in the brain and liver tissues was obtained. Very significant changes in the fatty acid composition of liver EPG and CPG could be found in the infants receiving TPN with Intralipidmainly an increase in 18∶2ω6, a decrease in the linoleate elongation/desaturation to longer members of the series and a decrease in the 22∶6ω3 levels of liver EPG and CPG. In the brain, only an increase in the 18∶2ω6 value of CPG, not accompanied by any increase in the longer ω6 fatty acids, could be detected. Possible adverse effects of high doses of 18∶2ω6 on the tissue levels of long chain polyunsaturated fatty acids (PUFA), especially of 22∶6ω3, are discussed.
Time course of incorporation of 20‐carbon polyunsaturated fatty acids in a human keratinocyte cell line
Authors: Punnonen Kari , Puustinen Taplo , Jansen Christer T. 
Published: November 2006

AbstractHuman keratinocytes (NCTC 2544) in culture were labeled with equal amounts of either14C‐arachidonic acid,14C‐dihomo‐γ‐linolenic acid or14C‐eicosapentaenoic acid. At various time points, the incubations were stopped and the distribution of the14C‐fatty acids was analyzed. All these eicosanoid precursor fatty acids were effectively incorporated into the cellular lipids of the keratinocytes, and the major radiolabeled individual lipid fraction was phosphatidylethanolamine. The distributions of arachidonic acid and dihomo‐γ‐linolenic acid within cellular lipids were rather the same. However, less eicosapentaenoic acid than either arachidonic acid or dihomo‐γ‐linolenic acid was incorporated into the phospholipids and, correspondingly, more eicosapentaenoic acid was incorporated into the nonphosphorus lipids. In the phosphatidylinositol + phosphatidylserine fraction, there was significantly less eicosapentaenoic acid than either arachidonic acid or dihomo‐γ‐linolenic acid. The present study suggests that these eicosanoid precursor fatty acids are effectively incorporated into the human keratinocytes and that the pattern of incorporation and distribution of eicosapentaenoic acid appears to differ slightly from that of either arachidonic acid or dihomo‐γ‐linolenic acid.
The formation of lysophosphatidylinositol phosphate in human platelet microsomes
Authors: Thomas L. M. , Holub B. J. 
Published: November 2006

AbstractThe formation of lysophosphatidylinositol phosphate (lysoPIP) from lysophosphatidylinositol (lysoPI) via kinase activity was studied in microsomal preparations from human platelets. For this purpose, [3H]lysoPI or [3H]phosphatidylinositol ([3H]PI) was prepared and incubated in the presence or absence of ATP, MgCl2 and Triton X‐100, and the appearances of radioactivity in [3H]lysoPIP and [3H]phosphatidylinositol phosphate ([3H]PIP), respectively, were monitored using thin layer chromatography. Both lysoPI and PI phosphorylations were completely dependent upon the presence of ATP and MgCl2 in the incubation medium; Triton X‐100 addition stimulated both reactions, with the stimulation of PI conversion being considerably greater than that for lysoPI conversion. The present results demonstrate that lysoPI can be converted to lysoPIP by phosphorylation in human platelet microsomes. The potential significance of this enzymatic reaction in stimulated cells is discussed in relation to the generation of inositol‐1,4,5‐trisphosphate, an important intracellular second messenger.
Platelet changes after a saturated fat meal and their prevention by dazmegrel, a thromboxane synthetase inhibitor
Authors: Belch J. J. F. , Saniabadi A. R. , McLaughlin K. , Forbes C. D. 
Published: November 2006

AbstractA saturated fat meal was given to 10 normal males both before and after pretreatment with UK38,485, a thromboxane synthetase inhibitor (Dazmegrel, Pfizer Central Research, Sandwich, Kent, United Kingdom). Following the fat meal at 2 and 4 hr there was laboratory evidence of platelet activation. Dazmegrel lowered baseline platelet activity and lessened platelet activation following the fat meal. This drug should be investigated further as a potential antithrombotic agent.
Biokinetics of and discrimination between dietaryRRR‐ andSRR‐α‐tocopherols in the male rat
Authors: Ingold K. U. , Burton G. W. , Foster D. O. , Hughes L. , Lindsay D. A. , Webb A. 
Published: November 2006

AbstractThe net rates of uptake of the natural (2R,4′R,8′R) diastereoisomer of α‐tocopherol (α‐T) and the biodiscrimination relative to its 2S‐epimer (2S,4′R,8′R) have been measured, in two experiments, for the blood and 21 tissues of male Sprague‐Dawley rats fed over a period of several months diets containing deuterium‐substituted forms of the α‐T acetates. Gas chromatography‐mass spectrometry was used to measure the amount of deuterated tocopherols taken up relative to the amount of nondeuterated tocopherol remaining. The measurements were performed at different times after the rats, placed for one month on a basal diet containing nondeuterated, natural α‐T acetate, were switched to a diet containing the same total quantity of deuterated forms of either natural α‐T acetate or a mixture of the acetates of the 2R‐ and 2S‐epimers (i.e.,ambo‐α‐T acetate). In experiment 1 the source of vitamin E in the replacement diet was trideuterio‐2R,4′R,8′R‐α‐T acetate. The data obtained provide the first direct measure of the rate at which natural vitamin E is replaced and augmented in the tissues of growing animals under normal laboratory dietary conditions. There are dramatic differences in the tissue kinetics; for example, the apparent half‐life of vitamin E, i.e., the time at which the total amount of ingested trideuterio‐α‐T taken up is the same as the amount of nondeuterated α‐T remaining, varies from ca. 1 wk for the lung to ca. 11 wk for the spinal cord. In experiment 2 the vitamin E in the replacement diet was an equimolar mixture of trideuterio‐2S,4′R,8′R‐ and hexadeuterio‐2R,4′R,8′R‐α‐T acetates. The results show that there is a preferential uptake of the natural diastereoisomer of α‐T by all tissues (except the liver during the first month). Examination of fecal material reveals that the biodiscrimination begins in the gut; the incomplete hydrolysis of the acetates shows clearly that this reaction proceeds to a greater extent with the natural diastereoisomer. The greatest discrimination of all the tissues examined was found to occur in the brain. After five months, the level of the deuterated natural diastereoisomer was more than five times that of the deuterated 2S‐epimer. These results have potential implications for human nutrition.
Studies of lipoproteins and fatty acids in maternal and cord blood of two racial groups in Trinidad
Authors: Taylor G. Oladunni , Albers John J. , Warnick G. Russell , Adolphson Janet L. , McFariane H. , Sullivan D. R. , West C. E. , Sri‐Hari V. , Edwards R. 
Published: November 2006

AbstractThe high mortality rate from coronary heart disease (CHD) among Indians compared to Negroes in Trinidad led us to test plasma lipid profiles to see whether dietary or genetic factors might be involved. There were no interracial differences in the composition of plasma cholesterol ester fatty acids of the tested women and neonates. This finding suggests that dietary fat does not account for the interracial difference in CHD, nor does the cause appear to be due to genetic differences in lipid profiles, as there was no significant difference between values for plasma triglycerides, total cholesterol, high density lipoprotein (HDL) cholesterol, apo‐I, apo‐II, apo B or cholesterol ester fatty acids in the cord blood of each racial group.Blood samples were collected from 69 nonpregnant and 71 postpartum, fasted Negro and Indian women. Also taken were 71 umbilical cord blood samples. The mean triglyceride level was significantly lower in the Negro nonpregnant and postpartum women than in the Indians. HDL cholesterol and apo‐I values were lower in the Indian women. There were no significant differences in the total cholesterol and apo B measurements. The triglyceride values for postpartum women were higher than those of the nonpregnant Negroes and Indians (75% and 47%, respectively), whereas the total cholesterol and HDL cholesterol, apo A‐I and apo A‐II ranged from 9% to 29% higher in the postpartum women. Apo B was about 40% higher postpartum in both ethnic groups.The high CHD rate of Indians in Trinidad cannot be explained by dietary factors, plasma total cholesterol or fatty acid composition. However, the lower level of HDL cholesterol and plasma A‐I could play a role in the higher CHD rate in Indians.
Analysis of volatile fatty acids in biological specimens by capillary column gas chromatography
Authors: Fleming S. E. , Traitler H. , Koellreuter B. 
Published: November 2006

AbstractA method was developed to analyze and quantify volatile fatty acids (VFA) such as acetic, propionic, butyric, isobutyric, valeric and isovaleric acids in biological specimens. To obtain good sample transfer into the chromatographic system an organic solvent had to be used together with an aqueous milieu, thus improving wetting properties of the liquid sample plug introduced into the column. Sample preparation was carried out under alkaline conditions in order to exclude or minimize sample losses due to sample transfer during the extraction and work‐up procedure. A cold on‐column injection was applied to avoid irregular discrimination of the various acids due to sample splitting and an automatic injection technique was used to accommodate the large number of samples generated from biological origin. Connection of a pre‐column of wide internal diameter (0.53 mm) to the analytical column (0.32 m) was optimized and adapted to the nature of the injection solvent mixture consisting of acetonitrile, water and hydrochloric acid. To obtain well‐separated and correctly quantifiable gas chromatographic peaks, it was essential to perform the chromatography under acidic aqueous conditions. Standard resolution conditions and response factors were evaluated. The chromatographic results of applying this method to biological specimens from both rats and humans are provided.
The use of iodine staining for the quantitative analysis of lipids separated by thin layer chromatography
Authors: Palumbo Giuseppe , Zullo Fulvio 
Published: November 2006

AbstractThe method described for quantitative estimation of lipids separated on thin layer chromatography plates exploits the observation that most lipids can be stained by iodine vapor and that, in “controlled” conditions, the intensity of this staining is proportional to the actual amount of lipid in the spot. The method consists of i) exposing the developed plate to iodine vapor; ii) spraying it with a suitable solvent to prevent halogen evaporation; iii) collecting the stained lipids by scraping the spots off the plate; and iv) determining by a rate‐sensing method the absorbed iodine. The final determination is performed by measuring spectrophotometrically (at 410 nm) the rate of decolorization of a solution of Ce(IV) by As(III) in strong acidic conditions. The reaction rate, which is positively related to the concentration of iodine, is derived from the slope of the absorbance change plotted vs time.Providing that standards and samples are stained simultaneously, a quantitative estimation of lipid components of a mixture is possible in a reasonable time with excellent accuracy and reproducibility. In our hands, the method has been successfully applied to several common phospholipids, long chain fatty acids, cholesterol and deoxycholate, and triacylglycerols, in the range of 5–60 μg.
Uptake of fatty acids by the developing rat brain
Authors: Anderson Gregory J. , Connor William E. 
Published: November 2006

AbstractPolyunsaturated fatty acids are avidly taken up by the developing rat brain. To explore the specificity of this process, [1‐14C]labeled 16∶0, 18∶2n−6, 18∶3n−3, and 22∶6n−3 each were co‐injected with [3H]18∶1n−9 into the jugular vein of two‐wk‐old functionally hepatectomized and shamoperated control rats. The radioactivities present in the brain, liver and serum were assessed 30 min after injection. Uptake of labeled fatty acids into brain lipids steadily increased with increasing degree of unsaturation, with more than twice as much uptake of 22∶6n−3 compared to 16∶0. Phosphatidylcholine was the principal radioactive species in the brain except for animals injected with [1‐14C]22∶6n−3, in which more of the label was incorporated into phosphatidylethanolamine. Determination of watersoluble oxidation products in the brain and serum revealed that the greater uptake of the more unsatrated fatty acids did not result from differences in rates of degradation.
Mevalonate 5‐pyrophosphate decarboxylase in isolated villus and crypt cells of chick intestine
Authors: Iglesias J. , Gonzalez‐Pacanowska D. , Caamaño G. , Garcia‐Peregrin E. 
Published: November 2006

AbstractMevalonate 5‐pyrophosphate decarboxylase was studied in isolated enterocytes obtained from duodenal, jejunal and ileal villi and crypts. In our assay conditions, decarboxylase activity was linear for 60 min and up to 0.3 mg of protein. The subcellular location of decarboxylase in chick enterocytes was investigated. About 94% of the total activity was recovered in the cytosol. The distribution of enzyme activity in epithelial cells also was studied. Maximal specific activity was found in cell fractions from jejunum followed by ileum and duodenum. About 80% of total activity was recovered in the villus cells, indicating an active role of these cells in cholesterogenesis. Ileal cells showed the highest cholesterol content. In all the intestinal epithelial cells assayed, free cholesterol represented about 95% of the total cholesterol.
Analysis of autoxidized fats by gas chromatography‐mass spectrometry: X. Volatile thermal decomposition products of methyl linolenate dimers
Authors: Frankel E. N. , Neff W. E. , Selke E. , Brooks D. D. 
Published: November 2006

AbstractHigh‐molecular weight compounds previously were found to be important secondary products from autoxidation of polyunsaturated fatty esters. The contribution of dimers to oxidative deterioration was investigated by analyzing their volatile thermal decomposition products by capillary gas chromatography‐mass spectrometry. Dimers were isolated by gel permeation chromatography from autoxidized linolenate and from the corresponding monohydroperoxides, cyclic peroxides and dihydroperoxides. Major volatile decomposition products identified from these oxidative dimers were similar to those formed from the corresponding monomeric hydroperoxides. However, dimers from linolenate hydroperoxides produced more propanal and methyl 9‐oxononanoate than the corresponding monomers but less methyl octanoate and much less or no 2,4‐heptadienal and 2,4,7‐decatrienal. Significant differences in minor volatile products also were observed between dimeric and monomeric products of methyl linolenate oxidation compounds. Mechanisms are suggested for the formation of volatile decomposition products from different dimeric structures. These dimers are believed to be important sources of volatile compounds contributing to flavor and oxidative deterioration of fats.
The influence of n‐6 and n‐3 fatty acids on kidney phospholipid composition and on eicosanoid production in aging rats
Authors: Barcelli Uno O. , Beach Dorothy C. , Pollak Victor E. 
Published: November 2006

AbstractChanges in eicosanoid production may contribute to some of the complications of the aging process such as atherosclerosis and glomerular sclerosis. Polyunsaturated fatty acids of the n‐6 and n‐3 series are precursors of eicosanoids. We fed diets containing safflower oil as a source of n‐6 fatty acids, fish oil as a source of n‐3 fatty acids or beef tallow as a source of saturated fats to three groups of normal rats from 2–18 months of age. We demonstrated incorporation of the n‐3 fatty acids, 20:5n‐3 and 22:6n‐3 into kidney phospholipids. Feeding of the diet containing n‐3 fatty acids was associated with a markedly decreased giomerular production of PGE, 6‐keto‐PGF1α and TXB2. It also decreased the aortic production of 6‐keto‐PGF1α and platelet production of TXB2. No significant effect of n‐6 fatty acids on dienoic eicosanoid production was observed. There were no adverse effects on kidney function as measured by urinary protein excretion and serum creatinine levels or on renal morphology by any diet. A diet enriched in n‐3 fatty acids for 18 months remains effective in decreasing dienoic eicosanoids in the aging rat.
Relative inhibitory potencies of flavonoids on 12‐lipoxygenase of fish gill
Authors: Hsieh R. J. , German J. B. , Kinsella J. E. 
Published: November 2006

AbstractThe relative efficacy of 10 flavonoid compounds and some common antioxidants in inhibiting 12‐lipoxygenase of fish gill was determined. Lipoxygenase activity was measured by oxygen consumption with polarography and formation of hydroxy fatty acid using thin layer chromatography with autoradiography. Generally, the inhibition of 12‐lipoxygenase by flavonoids was noncompetitive. The lipoxygenase product pattern did not change in the presence of flavonoids. Fisetin (3,3′,4′,7‐tetrahydroxyflavone) and quercetin (3,3′,4′,5,7‐pentahydroxyflavone) were the most potent inhibitors of 12‐lipoxygenase, with IC50's of 0.25 and 0.4 μM respectively. These were compared with IC50's values of 5, 1000 μM for BHA (t‐butylhydroxyanisole) and BHT (t‐butylhydroxytoluene) respectively. Possible inhibitory mechanisms and relationships between flavonoid structure and inhibitory potencies are discussed.
Inhibition of cytochrome c oxidase and hemolysis caused by lysosphingolipids
Authors: Igisu Hideki , Hamasaki Naotaka , Ito Akio , Ou Weija 
Published: November 2006

AbstractGalactosylsphingosine, glucosylsphingosine and sphingosine all inhibited cytochrome c oxidase activity in mitochondria from rat liver; more than 50% inhibition was caused by 5 μM lipid (0.1 μmol/mg mitochondrial protein). However, these lysosphingolipids did not suppress the activity of purified cytochrome c oxidase. When the enzyme was “reconstituted” with phosphatidylcholine, the lysosphingolipids clearly inhibited the activity. On the other hand, galactosylsphingosine, glucosylsphingosine and sphingosine all hemolyzed erythrocytes, indicating that lysosphingolipids can disrupt the membrane. Thus, it appears that the inhibition of cytochrome c oxidase, a membrane‐bound enzyme in mitochondria, is due to perturbation of the environment of the enzyme and that the primary attacking site of the lysosphingolipids is the membrane. Because the potency to inhibit cytochrome c oxidase and to hemolyze erythrocytes did not differ among these lysosphingolipids and because galactosylceramide caused neither inhibition of cytochrome c oxidase nor hemolysis, the free amino group in the lysosphingolipids seems to be essential to give the effects. In addition, both inhibition of cytochrome c oxidase and hemolysis caused by lysosphingolipids were completely abolished by albumin, suggesting that toxic effects of lysosphingolipids may not be apparent in blood.
Triterpene alcohols, 4‐methylsterols and 4‐desmethylsterols of eggplant seed oil: A new phytosterol
Authors: Farines Marie , Cocallemen Serge , Soulier Jacques 
Published: November 2006

Abstract4‐Desmethylsterols, 4‐methylsterols and triterpene alcohols of eggplant seed oil were isolated and characterized by1H nuclear magnetic resonance (NMR) and mass spectrometry. In addition to several compounds that have been shown to be present in eggplant seed oil, one triterpene alcohol and three sterols are described for the first time. One of these sterols, 14α‐methyl‐5α‐cholest‐9(11)‐en‐3β‐ol, never before had been observed in plant lipids.