bluuebunny/crossref_metadata_2025_split huggingface dataset:
The incorporation of14C‐glycerol into different species of diglycerides and triglycerides in rat liver slices
Authors: Hill Edward E. , Lands William E. M. , Slakey Sister P. M. 
Published: November 2006

AbstractThe relative rates of de novo synthesis of species of diglycerides and triglycerides from14C‐glycerol were examined in rat liver slices. Diglycerides containing one or two double bonds per molecule and triglycerides containing four or more double bonds per molecule represented 70% and 60% respectively of the newly synthesized diglycerides and triglycerides. The newly synthesized triglycerides were more unsaturated than the endogenous triglycerides. Our results suggest that a nonrandom synthesis of species of diglycerides occurred followed by an almost random utilization of the various diglyceride species for the biosynthesis of triglycerides.
Predicting the positional distribution of docosahexaenoic and docosapentaenoic acids in aquatic animal triglycerides
Authors: Litchfield Carter 
Published: November 2006

AbstractThe positional distribution of 22∶6 and 22∶5 in aquatic animal triglycerides can be predicted by simple proportionality equations of the typey=kx. The mole % 22∶6 at the 1, 2, or 3 position (y) is obtained by multiplying the proportionality constant for that position (k1,k2, ork3) times the mole % 22∶6 in the total triglycerides (x). For fish and invertebrate triglycerides,k1=0.28,k2=2.06, andk3=0.66. For marine mammal blubber triglycerides,k1=0.94,k2=0.22, andk3=1.84. The same equations apply to both 22∶6 and 22∶5.
Hydroxy fatty acids from cerebrosides of the central nervous system: GLC determination and mass spectrometric identification
Authors: Capella P. , Galli C. , Fumagalli R. 
Published: November 2006

AbstractA method has been developed for GLC determination of hydroxy fatty acids (HFA) from cerebrosides of the central nervous system.Identification of HFA present in complex biological mixtures was achieved by the use of the combination gas chromatography— mass spectrometry. GLC separations and mass spectrometric determinations were carried out on the trimethylsilyl derivatives of HFA, which show excellent GLC characteristics and favorable cleavages to determine the position of OH groups on the aliphatic chain. The mass spectra of these derivatives present some unusual rearrangement ions, whose composition has been studied with the aid of deuterium labeled analogs.
Dietary induced alterations in swelling characteristics and endogenous phospholipase A2 activity of rat liver mitochondria
Authors: Waite Moseley , Van Golde L. M. 
Published: November 2006

AbstractThe present study describes the rapid alterations in the fatty acid patterns of phosphatidyl choline and phosphatidyl ethanolamine from rat liver mitochondria induced by corn oil feeding to EFA‐deficient rats. Simultaneous changes occurring with comparable rates were observed in the swelling properties and phospholipase A2 activity of the mitochondria. Mitochondria isolated from the liver of EFA‐deficient rats exhibited a high tendency to swell and a high phospholipase A2 activity in comparison with those prepared from normal rat liver. Feeding of corn oil for 48 hr to the EFA‐deficient rats completely reduced this high rate of swelling and phospholipase A2 activity to the normal level. In the same time eicosatrienoic acid, a characteristic fatty acid constituent of phospholipids from EFA‐deficient animals, was replaced by the more common fatty acids, linoleic and arachidonic. The possible relationship between fatty acid constituents of phospholipids, swelling properties and phospholipase A2 activity in rat liver mitochondria are discussed.
Lipids and the pill
Authors: Alfin‐Slater R. B. , Aftergood L. 
Published: November 2006

AbstractThe widespread use of anovulatory compounds and the well‐known effects of sex hormones on various aspects of metabolism prompted this review of our work and the work of others on observed changes in lipid metabolism resulting from the administration of oral contraceptives and their components. In the rat, female sex hormone administration results in a decreased plasma cholesterol level, an accumulation of cholesterol in liver and a decreased hepatic cholesterol biosynthesis. On the other hand, cholesterol biosynthesis is enhanced in ovaries and adrenals. There is also a diminished alpha lipoprotein content and a corresponding decrease in the alpha/beta lipoprotein ratio. In some cases these changes are comparable to those observed during pregnancy. The results of sex hormone administration to women are more variable. In this case the most often observed effect is hypertriglyceridemia. Changes in lipoprotein content and distribution are also evident and may be the result of changes in metabolism in the liver, e.g., lipid synthesis or lipid transport from liver to plasma and tissues, or both. Many of these changes may be mediated indirectly through the action of estrogenprogestin on other hormones. In both species the effects of oral contraceptives are attributable principally to the estrogen component. The combination of estrogen with progestin compounds, which constitutes the oral contraceptive, modifies the effects of estrogen administered alone.
Fatty acid synthesis in rat testes injected intratesticularly or incubated with 1‐14C acetate
Authors: Evans O. B. , Zseltvay Richard , Whorton Richard , Coniglio John G. 
Published: November 2006

AbstractFatty acid synthesis was studied in testes of young and adult rats either injected intratesticularly or incubated with 1‐14C acetate. The pattern of14C incorporation into lipids and individual fatty acids in the two age groups was similar but results obtained with intratesticular injection differed considerably from those obtained in the in vitro studies. In the former more than 70% of the14C incorporated in total lipids was in phosphatides, with about 15% in triglycerides and only minor amounts in cholesteryl esters and free fatty acids. Most of the14C incorporated into total fatty acids was in saturated acids (predominantly 16∶0). A small amount of14C was in the higher polyenes and there was a progressive increase with time after acetate injection in the14C content of 22∶5 W6. In testes incubated with 1‐14C acetate, the phosphatide, triglyceride, and free fatty acid fractions had similar amounts of14C. In the total fatty acid fraction about 40% of the incorporated14C was in saturated acids (predominantly 14∶0 and 16∶0) and about 50% in the higher polyenes. Twenty carbon polyenes and 22∶5 W6 had significant14C incorporation, but most of the14C was in 22∶4 W6. About 80% of the14C in the latter compound was in the carboxyl carbon, indicating its origin from endogenous 20∶4 W6 elongated by the added 1‐14C acetate used as substrate. The14C 22∶4 was present predominantly in the triglyceride and phosphatide fractions with minor amounts in other lipids.14C‐labeled compounds of retention time greater than 22∶5 were also present in all lipid fractions.
Fluorescent products of lipid peroxidation of mitochondria and microsomes
Authors: Dillard C. J. , Tappel A. L. 
Published: November 2006

AbstractLiver microsomes and mitochondria and heart sarcosomes from rats fed diets with varying α‐tocopherol concentrations and lipid contents were peroxidized over a 6 hr time period. Lipid peroxidation was measured by absorption of oxygen, production of thiobarbituric acid (TBA) reactants and by development of fluorescence. The spectral characteristics of the fluorescent compounds were the same for all peroxidizing systems; the excitation maximum was 360 nm and the emission maximum was 430 nm. As time of peroxidation increased, uptake of oxygen and production of fluorescent compounds increased. These two parameters as well as production of TBA reactants were dependent upon dietary antioxidant and all three had an inverse relationship with the amount of dietary α‐tocopherol. The relationship between absorption of oxygen and development of fluorescent compounds was also dependent upon dietary polyunsaturated fats (PUFA). Subcellular particles from animals fed higher levels of PUFA produced more fluorescent products per mole of oxygen absorbed than did those from animals on a diet with lower PUFA content. TBA reacting products increased with time during the initial phase of peroxidation: in the microsomal systems their production stabilized or decreased by 4–6 hr of peroxidation. Using the synthetic 1‐amino‐3‐iminopropene derivative of glycine as standard for quantitation of fluorescence, the molar ratios of oxygen absorbed per fluorescent compound produced were calculated. This ratio for subcellular particles isolated from rats fed diets with PUFA ratios similar to those in the average American human diet was 393∶1. The fluorescent compounds had the same spectral characteristics as the lipofuscin pigment that accumulates in animal tissues as a function of age, oxidative stress or antioxidant deficiency. The fluorescent molecular damage represented by that accumulated in human heart age pigment by 50 years of age was calculated to have been caused by approximately 0.6 μmole of free radicals per gram of heart tissue.
Net esterification in vitro of plasma cholesterol in human primary hyperlipidemia
Authors: Marcel Yves L. , Fabien Hélène D. , Davignon Jean 
Published: November 2006

AbstractNet esterification of cholesterol was studied in vitro in the plasma of normal subjects and of patients with different types of hyperlipidemia. Net esterification of cholesterol was found to be significantly enhanced in types IIa, IV and V of human primary hyperlipidemia. In the plasma of all normal and hyperlipidemic subjects taken as a group, net esterification of cholesterol is significantly correlated with free cholesterol (p<0.001) and with phosphatidyl choline (p<0.001).
Mass spectrometric analysis of mono‐ and dialkyl ethers of diols
Authors: Kramer John K. G. , Holman Ralph T. , Baumann Wolfgang J. 
Published: November 2006

AbstractMass spectra of homologous series of long chain mono‐ and dialkyl ethers of ethanediol and propanediols were measured and general patterns of fragmentation were established. Both classes of diol lipids produce ions which are characteristic for the alkoxy moieties as well as ions which are typical of the constituent short chain diols. Prominent ions are formed by cleavages α and β to the ether oxygen and by rearrangement of one or two hydrogens and concurrent fission. High resolution mass spectrometry and deuterium labeling techniques were used to verify the composition of ions and to substantiate fragmentation mechanisms.
Synthesis of C‐18 mixed acid diacyl‐sn‐glycerol enantiomers
Authors: Buchnea Dmytro 
Published: November 2006

AbstractProcedures have been developed for the synthesis of both enantiomeric forms of mixed fatty acid, saturated and polyunsaturated 1,2‐diacyl‐sn‐glycerols and 2,3‐diacyl‐sn‐glycerols from D‐mannitol as starting material. The following diacyl‐sn‐glycerols have been synthesized: 1‐Stearoyl‐2‐linoleoyl‐sn‐glycerol, 1‐stearoyl‐2‐linolenoyl‐sn‐glycerol, 2‐linoleoyl‐3‐stearoyl‐sn‐glycerol and 2‐linolenoyl‐3‐oleoyl‐sn‐glycerol. Their specific rotations, refractive indices, densities, solubilities, carbon and hydrogen analysis and iodine values have been reported.
Effects of pure oxygen atmosphere in vivo on plasma lecithin‐cholesterol acyltransferase reaction
Authors: Mikel Hubert S. , Foulds Emmet L. , Clark Dale A. , Larkin Edward C. 
Published: November 2006

AbstractExposure to pure oxygen atmospheres for more than three days resulted in loss of red blood cell mass in astronauts in some flights. Oxidation of lipid or protein membrane components may account for this phenomenon, since tocopherol deficient red blood cells have been shown to hemolyze on exposure to elevated oxygen pressures in vitro and in vivo. An additional contributing cause to the induced red cell loss may be the inhibition of the plasma lecithin‐cholesterol acyltransferase reaction by oxygen, since congenital absence of the enzyme is associated with anemia. This possibility was explored in eight human subjects who lived in a sealed environmental chamber and breathed 100% oxygen at 258 mm Hg pressure for 30 days. In their plasma a 40% decrease in the conversion of free cholesterol to ester was demonstrated in vitro after four weeks’ exposure to 100% oxygen. Plasma cholesteryl ester concentration was also decreased. Red blood cell mass was reduced and erythropoiesis was depressed. These findings support the hypothesis that the anemia induced by exposure to 100% oxygen was caused in part by decreased synthesis of cholesteryl esters secondary to an inhibition of the plasma lecithin‐cholesterol acyltransferase reaction.
Effects of renal factors on in vitro hepatic cholesterol synthesis in the rat
Authors: Haven Guy T. , Jacobi Herbert P. 
Published: November 2006

AbstractTwo products derived from rat renal tissue have been shown to affect in vitro hepatic cholesterol synthesis. A premevalonate inhibitor of hepatic cholesterol synthesis is associated with the membranes of the renal endoplasmic reticulum. It is stable at −75 C and at 4 C but is heat labile. A pre‐mevalonate stimulator of in vitro hepatic cholesterol synthesis is located within renal lysosomes and can be prepared in a nonsedimentable form by extraction with hypotonic buffer. While it is stable at −75 C, it loses activity at 4 C. Both of these products appear to have a molecular weight in excess of 150,000 as determined by gel filtration.
The structural analysis of wheat flour glycerolipids
Authors: Arunga R. O. , Morrison W. R. 
Published: November 2006

AbstractThe compositions of the fatty acids in the 1, 2 and 3 positions of the principal glycerolipids and their various stereoisomers were determined. Fatty acids in the 1 and 3 positions of triglycerides were similar in composition and less unsaturated than those in the 2 position. Fatty acids in the 1,2‐, 1,3‐ and 2,3‐diglycerides were distributed in a pattern which indicated isomerization ofsn‐1,2‐diacylglycerol. Lysophosphatidyl choline (the principal monoacyl lipid) consisted of about 80% 1‐acyl and 20% 2‐acyl isomers. The fatty acid compositions indicated that most of the 2‐lysophosphatidyl choline was formed by isomerization of 1‐lysophosphatidyl choline. Most of the digly cerides and lysophosphatidyl choline were synthesized in the ripening wheat grain. However a small proportion of these partial glycerides and all of the other minor partial glycerides (monoglycerides, digalactosyl monoglycerides) appeared to be the result of limited lipolysis of the corresponding diacyl lipids in the wheat or in the freshly‐milled flour. Fatty acids in the 2 position of all the fully acylated glycerides were very similar in composition, but there were considerable differences in the 1 position fatty acids.
Studies on the nuclear magnetic resonance spectra of olefinic protons of conjugated fatty acid methyl esters
Authors: Suzuki Osamu , Hashimoto Tetsutaro , Hayamizu Kikuko , Yamamoto Osamu 
Published: November 2006

AbstractThe NMR spectra of olefinic protons in the four representative conjugated fatty acid methyl esters, methylcis‐9,trans‐11‐octadecadienoate, methyltrans‐9,trans‐11‐octadecadienoate, methyl α eleostearate, and methyl β eleostearate, were studied. The chemical shift of each olefinic proton in these compounds was determined by considering their intramolecular environment. Coupling constants were also obtained as the results of spectral analysis.
Preparation of3H‐phosphatidylmyoinositol withKloeckera brevis
Authors: Prottey Colin , Seidman Michael M. , Ballou Clinton E. 
Published: November 2006

AbstractThe growth ofKloeckera brevis in the presence of uniformly tritiated myoinositol is described. The major radioactive lipid isolated from the cells is3H‐phosphatidylmyoinositol, labeled exclusively in the myoinositol moiety. Chromatographic methods for purifying3H‐phosphatidylmyoinositol, free from other labeled lipids, are described, and the use of this labeled lipid as a precursor in studying enzymatic synthesis of complex inositol lipids is demonstrated.
Liver lipids of the polar bear,Thalarctos maritimus
Authors: Gershbein Leon L. , Singh Eric J. 
Published: November 2006

AbstractThe distribution of total and free fatty acids as well as the acids from the glycerides, sterol esters and phospholipids of polar bear liver lipids was ascertained and found to contain somewhat higher levels of unsaturated components as compared to those of such mammals as the pig. Saponification of the liver lipids yielded the hydrocarbons, alcohols and sterols which were analyzed by GLC. The hydrocarbons occurred at an overall level of 55 mg/kg liver or 57.9 mg/100 g total lipids, of which pristane and other saturated hydrocarbons, mainly normal homologs, comprised 2.6 and 5.3 mg/100 g, respectively; the remainder contained squalene (37.7 mg/100 g) and other unsaturated types (12.3 mg/100 g). As based on the total lipids, the levels of fatty alcohols, sterol and glyceryl ethers amounted to 1.65%, 5.9% and 0.03%, respectively. The fatty alcohols displayed about 31 peaks of C12 to C30, of which the hexadecanol and a branched C20 component were prominent.
Chain length specificity of the saturated fatty acyl desaturase in rat liver preparations
Authors: Raju P. K. , Reiser Raymond 
Published: November 2006

AbstractChain length specificity of the saturated fatty acyl desaturase was studied in rat liver preparations using both de novo synthesized long chain fatty acids and equimolar mixtures of preformed fatty acids. Both experiments show that myristic acid is least desaturated and palmitic and stearic acids are desaturated in about equal amounts.
Lipolysis, esterification and glucose oxidation by human omental isolated adipose cells: The effects of pH, buffer and epinephrine
Authors: Ashley B. C. E. , Goldrick R. B. 
Published: November 2006

AbstractThe rates of glycerol productions, glucose oxidation and glucose conversion to glyceride‐glycerol by human omental fat cells were compared in vitro at pH's from 7.0 to 8.4, with and without epinephrine, and in both Krebs‐Ringer‐bicarbonate and‐phosphate buffers. Basal glycerol production was not significantly altered by changes in pH, and was similar in each buffer. Epinephrine markedly increased glycerol production at each pH in both buffers, but significantly more was produced at pH 8.4 than at pH 7.4. Basal glucose metabolism was not affected by pH or by the type of buffer. Epinephrine caused a small increase in glucose oxidation at each pH in bicarbonate buffer but only at pH 7.8 in phosphate buffer, and had no effect on glucose conversion to glyceride‐glycerol.
Isotope effects in the desaturation of stearic to oleic acid
Authors: Johnson A. R. , Gurr M. I. 
Published: November 2006

AbstractComparisons have been made of the rates of desaturation of stearic to oleic acid using a series of differently labeled forms of the substrate and two different methods of assay. The reaction has been measured either by analyzing the amount of labeled oleic acid produced, or by analyzing the amount of tritium released into water from [9,10‐3H2]‐labeled substrates. The rate of desaturation of [1‐14C] stearic acid has been compared with that of [threo‐9,10‐3H2] and [erythro‐9,10‐3H2] stearic acids in which about 99% of the label was at the 9 and 10 positions and in which most of the labeled molecular species contained two tritium atoms. A further series of [erythro‐9,10‐3H2] stearates was used in which there was a greater proportion of tritium at positions other than 9 and 10 or a greater proportion of species containing only one tritium atom, or both. In the tritium release assay the enzyme discriminated against the tritium substrates, the discrimination being greater witherythro‐ditritio‐compounds than with monotritio orthreo‐ditritio‐compounds. The isotope effect was also observed when [3H] stearoyl‐CoA thiol esters were the substrates, and when the source of the enzyme was the green algaChlorella vulgaris. Despite the isotope effect, the release of tritiated water can be used as an assay of desaturase activity. If the absolute value of enzymic activity is required, however, the location and stereochemistry of the tritium atoms should be known or the method standardized against [1‐14C] stearic acid.
Sterol metabolism: XII. 26‐hydroxycholesterol in commercial cholesterol
Authors: Van Lier Johan E. , Smith Leland L. 
Published: November 2006

AbstractCommercial cholesterol of bovine brain and spinal cord origin has been care‐fully examined for its 24‐ and 26‐hydroxycholesterol content. By alternate adsorption chromatography and chromatography on Sephadex LH‐20 26‐hydroxycholesterol was isolated from this course in 15 μg/g amounts, whereas 24‐hydroxycholesterol was not observed.
Glycerides ofLimnanthes douglasii seed oil
Authors: Phillips Bruce E. , Smith C. R. , Tallent W. H. 
Published: November 2006

AbstractBrockerhoff‐type procedures were used to determine the amounts of each acyl group at each glyceride position ofLimnanthes douglasii seed oil. During the course of the analyses, small quantities of three acids isomeric with those previously found in the oil were identified by their ozonolysis products and their gas‐liquid chromatographic (GLC) behavior. The newly discovered constituents of the oil were 3‐octadecenoic acid (0.1%), 5‐octadecenoic acid (0.9%) and 11‐eicosenoic acid (3%). The saturated acids and those with ω‐9‐unsaturation are esterified most often to β‐glyceride positions inLimnanthes seed, while the acids with Δ5‐unsaturation occur generally at the outer glyceride positions. Although the Δ5‐unsaturated acids as a group exhibited no obvious preference for one outer position over the other, individual acids were unequally distributed between the 1‐ and 3‐sn‐glycerol positions. The probabilities of occurrence of the various triglycerides were calculated from the stereospecific analysis data by assuming a 1‐random, 2‐random, 3‐random distribution of the acyl groups. The calculations are in agreement with the composition of the whole oil, as determined by GLC.
Potential function of cholesterol in blood coagulation: Amplification of phospholipid thromboplastic activity
Authors: Sorbye Oyvind , Phillips Fred C. , Lundberg W. O. 
Published: November 2006

AbstractRecalcification tests have revealed a two‐ to threefold increase in the thromboplastic activity of recombined phospholipid fractions from chicken erythrocyte lipids on supplementation with the original concentration of cholesterol. An optimal four‐ to fivefold increase was obtained at higher levels. Cholesterol esters had no such effect and clotting times with Russell's viper venom were not similarly affected.
Gas chromatographic separation of linoleic acid hydroperoxides as trimethylsilyl ethers of methyl hydroxystearates
Authors: Eriksson C. E. , Leu Karin 
Published: November 2006

AbstractThe primary products, 9‐ and 13‐hydroperoxy‐octadecadienoic acids, from lipoxygenase catalyzed oxidation of linoleic acid, were converted into the trimethylsilyl ethers of methyl 9‐ and 13‐hydroxystearates which were completely separated by gas chromatography on an OV‐17 methyl silicone (50% phenyl groups), capillary column.