bluuebunny/crossref_metadata_2025_split huggingface dataset:
Utilization of various sterols by lecithin‐cholesterol acyltransferase as acyl acceptors
Authors: Piran Uri , Nishida Toshiro 
Published: November 2006

AbstractHighly purified lecithin‐cholesterol acyltransferase of human plasma was used to study the utilization of various sterols as the acyl acceptor. The esterification of sterols was facilitated by the presence of a 3β‐hydroxyl group and thetrans configuration of the A/B rings, as was evident from the lack of acceptor activity of all 3α‐hydroxy sterols tested and coprostanol. Cholesterol analogs in which the side chain is modified, such as campesterol, β‐sitosterol, desmosterol and stigmasterol, were less effective than cholesterol as acyl acceptors. However, androstan‐3β‐o1, which completely lacks the side chain, was found to be more active than cholesterol. The transfer of the acyl group to all effective sterols required the presence of the cofactor peptide apolipoprotein A‐I.
β‐oxidation of the coenzyme A esters of vaccenic, elaidic, and petroselaidic acids by rat heart mitochondria
Authors: Lawson Larry D. , Kummerow Fred A. 
Published: November 2006

AbstractRates of β‐oxidation of the coenzyme A esters of vaccenic, elaidic, and petroselaidic acids as well as their respectivecis isomers by rat heart mitochondria were measured and compared. At all concentrations studied, vaccenoyl‐CoA was oxidized more rapidly than elaidoyl‐CoA, but more slowly than oleoyl‐CoA except at high substrate concentrations. Alltrans octadecenoyl‐CoA esters were oxidized at a slower rate than their respectivecis or saturated isomers. Oxidation rates decreased as the double bond approached the carboxyl‐end.
Isolation and identification of the metabolites of 22,25‐dideoxyecdysone from cockroach fat body cultures
Authors: Thompson Malcolm J. , Robbins William E. , Dutky Samson R. , Marks Edwin P. , Filipi Patricia A. , Finegold Harold 
Published: November 2006

AbstractHydroxylation and conjugation were the principal pathways of metabolism of 22,25‐dideoxyecdysone in cockroach fat body cultures. The major metabolite isolated and identified was the tetrahydroxy steroid 22‐deoxyecdysone; other exdysteroids isolated, in order of decreasing quantities, were 22‐deoxy‐26‐hydroxyecdysone, 22,25‐dideoxy‐26‐hydroxyecdysone, and 22‐deoxy‐20‐hydroxyecdysone. Cockroach fat body from late‐instar nymphs appears to lack the mechanism for hydroxylating at C‐22. Radioanalyses of the material obtained from enzymic hydrolysis of the conjugate fraction showed 65, 15 and 20% of tetraols, pentaols, and unhydrolyzed conjugates respectively, and no 22,25‐dideoxyecdysone. An azasteroid and two nonsteroidal amines that effectively inhibit the activity of 22,25‐dideoxyecdysone in the cockroach leg regenerate‐fat body culture system enhanced the metabolism of 22,25‐dideoxyecdysone, decreased the quantity of the pentaol fraction present, and caused an increase or accumulation of the tetraol and conjugate fractions in the fat body culture system.
Uptake and utilization of 1‐14C palmitic acid by heart cells treated with fresh or thermally oxidized fats
Authors: Bird Ranjana P. , Alexander J. C. 
Published: November 2006

AbstractThe effects of fractions isolated from thermally oxidized corn oil or olive oil on the metabolic activity of heart endothelial and muscle cells were studied. Rat heart cells in culture, exposed to thermally oxidized fat components, took up more exogenous 1‐14C‐palmitic acid and incorporated more of it into the cell triacylglycerol fraction than when the cells were treated with fresh fats. Particularly with the heated corn oil compared to fresh corn oil, much less of the radioactivity from the labeled palmitic acid was deposited in the phospholipid fraction. Also, with heated corn oil when the incubation period was extended beyond 12 hr, there was a decline in the radioactivity retained in the triacylglycerol fraction of the heart muscle cells. When the fresh fats were compared for14C‐radioactivity incorporation into the heart cells, the olive oil gave much higher values, indicating a distinct difference in response to the proportion of fatty acids supplied.
Alpha tocopherol levels in various regions of the central nervous systems of the rat and guinea pig
Authors: Vatassery G. T. , Younoszai R. 
Published: November 2006

AbstractThe alpha tocopherol contents of various discrete anatomical regions in the central nervous system of adult rats and guinea pigs were assayed using a liquid chromatographic method. All parts of the guinea pig nervous system had lower alpha tocopherol contents per gram wet, dry or lipid weights than the corresponding areas in the rat. In both animals the distribution of alpha tocopherol did not correspond to the distribution pattern of total lipid. There was also a rostral to caudal concentration gradient with respect to alpha tocopherol content; gray matter from cerebral hemisphere has the highest concentration and cervical spinal cord the least. In both animals alpha tocopherol contents per gram dry weight or lipid weight were higher in gray matter areas when compared with white matter areas. The low concentration of alpha tocopherol in spinal cord could make this region more susceptible to damage from deficiency than the rest of the central nervous system.
Isolation and characterization of phospholipase D from fababeans
Authors: Atwal A. S. , Eskin N. A. M. , Henderson H. M. 
Published: November 2006

AbstractAn enzyme activity in crude extract of fababeans hydrolyzed phosphatidylcholine‐U‐14C to produce choline and phosphatidic acid. This enzyme, phospholipase D, was stable at 50 C in the presence of 5 mM DTT but was inactivated at 55 C. The enzyme was precipitated with cold acetone, concentrated between 30% saturation to 40% saturation with ammonium sulphate, absorbed on calcium phosphate gel and eluted with 0.2 M phosphate buffer. This procedure resulted in a 20‐fold increase in specific activity. The activity of fababean phospholipase D was much higher when assayed at 38 C than that at room temperature. There was an obligatory requirement for calcium, and for maximal activity 40 mM calcium was required. A narrow pH optimum of about pH 5.7 was observed. The enzyme activity was extremely dependent on substrate dispersion. When 5 mM phosphatidylcholine (PC) was sonicated with increasing levels of sodium dodecyl sulphate (1 mM to 4 mM), the enzyme activity kept increasing. By using equimolar concentrations of PC and sodium dodecyl sulphate (1 mM to 5 mM), the Michaelis constant (Km) was estimated to be 1.74 mM. Addition of choline and serine at 10 mM concentration reduced phospholipase D activity by 31% and 22%, respectively.
Differential alteration of Δ9 and Δ6 desaturation of fatty acids in rat brain preparations in vitro
Authors: Cook H. W. 
Published: November 2006

AbstractDeveloping rat brain has the capacity for either Δ9 or Δ6 desaturation of fatty acids. In liver, evidence supports the existence of separate enzymes for each reaction, but it is not known whether in brain Δ9 or Δ6 desaturation of saturated fatty acids involves distinct enzymes. We have used fatty acids, including the cyclopropene fatty acid, sterculic acid, to alter desaturation activities with substrates that are desaturated predominantly in the Δ9 position or in the Δ6 position. In addition, differential alteration of desaturation of plamitic acid, a substrate that can be desaturated in either the Δ9 or Δ6 positions by brain preparations from neonatal rats, was examined. Sterculate reduced Δ9 desaturation of palmitate 80–90% but reduced Δ6 desaturation only 35%. In contrast, linoleic acid preferentially reduced Δ6 desaturation of palmitate. Thus, Δ9 desaturation of saturated fatty acids appears to be catalyzed by an enzyme or enzyme site distinct from that for Δ6 desaturation. Accordingly, these activities may be independently regulated during crucial stages of brain development.
Lipid composition of morris hepatoma 5123c, and of livers and blood plasma from host and normal rats
Authors: Ruggieri S. , Fallani A. 
Published: November 2006

AbstractThe lipid composition of Morris hepatoma 5123c was analyzed together with that of liver and blood plasma from both normal and tumor‐bearing rats. The results showed that the liver of tumor‐bearing rats contained higher amounts of glycerides, cholesteryl esters, free fatty acids and phospholipids than the liver of normal rats. In the blood plasma of tumor‐bearing rats, there was an increase of free cholesterol and triglycerides; this latter difference, however, was not statistically significant. Acyl chain changes in the liver of tumor‐bearing rats consisted of an increase of palmitic and oleic acids and a decrease of stearic and arachidonic acids in phosphatidylinositol. Morris hepatoma 5123c contained a lower amount of triglycerides than the livers (both host and normal) and showed a significant decrease of total phospholipids when compared to the host liver. The major acyl chain changes found in Morris hepatoma 5123c compared with both normal and host rat livers were: a) a higher percentage of arachidonic acid together with a lower proportion of palmitic acid in cholesteryl esters; b) an increase of stearic and arachidonic acids and a decrease of palmitic acid in triglycerides; and c) a higher level of palmitic and oleic acids associated with a lower percentage of stearic and C22 polyunsaturated acids in phosphatidylcholine.
The influence of phthalate esters on human plasma lecithin/cholesterol acyltransferase
Authors: Lagente M. , de la Farge F. , Valdiguie P. 
Published: November 2006

AbstractThe effect of various phthalate esters on the lecithin/cholesterol acyltransferase activity in man was studied in vitro. The enzymatic activity was strongly reduced with all phthalates except for the dimethyl phthalate. The inhibition rate depends on the phthalate concentration and also on the carbon number of the alkyl groups of phthalates.
Uptake of [14C] choline and incorporation into lung phospholipid by the isolated perfused rat lung
Authors: Johnson Rodger G. , Lugg Moira A. , Nicholas Terence E. 
Published: November 2006

AbstractWe have used the isolated perfused lung (IPL) preparation from the rat to determine whether uptake of choline from the vascular compartment could limit the rate of synthesis of phosphatidylcholine (PC). The uptake of choline was rapid and did not saturate at a concentration of 10 mM. The rate of incorporation of choline into phospholipid was saturated above 0.1 mM choline. Whereas, uptake and incorporation were depressed at 4 C, uptake was neither dependent on the extracellular sodium concentration nor inhibited by equimolar concentrations of hemicholinium‐3 (HC‐3). We could find no evidence that uptake might limit synthesis of lung lecithin and conclude that uptake is either by free diffusion, or by a carrier‐mediated process with a very high Km.
Identification of novel octadecadienoic fatty acids in the seaweedCladophora rupestris through oxidative ozonolysis of the alcohols prepared from the acids
Authors: Ratnayake W. N. , Ackman R. G. 
Published: November 2006

AbstractThe BF3−MeOH reagent for ozonolysis of ethylenic unsaturation does not oxidize alcohols. It is therefore feasible to determine the position of ethylenic unsaturation in long chain fatty alcohols of synthetic or natural origin by recovering the methyl ester products intact and silylating the alcohol function of half‐ester, half‐alcohol, products prior to gas liquid chromatographic analysis. The C3 fragment from methylene‐interrupted alkyl chains is not recovered, but, by first reducing carboxyl ester groups to alcohols, the terminal difunctional products can be identified in nonmethylene‐interrupted dienoic fatty acids. The seaweedCladophora rupestris is shown to contain Δ5,Δ11‐,Δ8,Δ11‐, and Δ11, Δ14‐ as well as Δ9,Δ12‐octadecadienoic acid.
Separation and identification of prostaglandin A1 in onion
Authors: Attrep Katherine A. , Bellman William P. , Attrep Moses , Lee James B. , Braselton W. E. 
Published: November 2006

AbstractThe separation of a fraction corresponding to prostaglandin A1 from yellow onion (Allium cepa) and subsequent purification of that fraction as prostaglandin A1 has led to the identification of prostaglandins in a plant material for the first time. Kilogram quantities of onions were processed and purified by extraction procedures, column chromatography and thin layer chromatography (TLC). Prostaglandin A1 was characterized and identified by a combination of comparative TLC, gas chromatography‐mass spectrographic analysis and blood pressure lowering properties. The results of these experiments are consistent with standard prostaglandin A1. It is concluded that prostaglandin A1 is present in onion.
Relative susceptibility of microsomes from lung, heart, liver, kidney, brain and testes to lipid peroxidation: Correlation with vitamin E content
Authors: Kornbrust Douglas J. , Mavis Richard D. 
Published: November 2006

AbstractRates of in vitro lipid peroxidation of microsomes and homogenates were found to vary widely among different tissues and species. In rats and rabbits, lung microsomes peroxidized at a 25‐ to 50‐fold lower rate than liver, kidney, testes and brain microsomes. Heart microsomes peroxidized at a rate slightly greater than, but most similar to, lung microsomes. Comparison of tissue homogenates also revealed the unique resistance of lung and heart to lipid peroxidation. The ratio of vitamin E to peroxidizable polyunsaturated fatty acids in lung and heart microsomes was several‐fold higher than in microsomes from the other tissues studied, which accounted for the relative resistance of lung and heart to lipid peroxidation. Liposomes of extracted rat lung microsomal lipid were also resistant to peroxidation and the amount of vitamin E contained in the lung lipid extract was sufficient to confer the same degree of resistance when incorported into an equivalent amount of rat liver lipid. Higher rates of peroxidation in mouse lung microsomes relative to rabbit, rat and human lung microsomes were similarly correlated with a lower ratio of vitamin E to peroxidizable fatty acids in mouse lung microsomes. These data provide strong support for the role of vitamin E as the major cellular antioxidant, especially in the highly oxygenated tissues of heart and lung, and demonstrate the utility of the microsomal system in characterizing tissue differences in susceptibility to peroxidative membrane decomposition.
Skin surface lipids of the horse
Authors: Downing Donald T. , Colton Vi Sabin W. 
Published: November 2006

AbstractSkin surface lipids from the sides of male and female horses (Equus caballus) were collected in acetone and analyzed by thin layer chromatography and gas liquid chromatography. The sole components in both sexes were cholesterol, cholesteryl esters and the lactones of 32‐, 32‐ and 36‐carbon ω‐hydroxy acids, each including a methyl group in the n−1 position. Most of the lactones were mono‐unsaturated (either n−8 or n−10), but small amounts of saturated and dienoic species were present. A pooled sample of the skin surface lipids contained 14% cholesterol, 38% cholesteryl esters and 48% lactones.
Analysis of subcellular phosphatidyl choline in developing rabbit lung
Authors: Gutcher Gary R. , Zachman Richard D. , Tsao Francis H. C. 
Published: November 2006

AbstractPhosphatidyl choline is a major lung surfactant. Insufficient development of the surfactant in neonates is often associated with the Respiratory Distress Syndrome. The concentration and fatty acid composition of phosphatidyl choline have not been studied in the subcellular organelles of the developing lung. This study has investigated the development of the concentration and fatty acid composition of phosphatidyl choline in subcellular fractions of 28‐day and 30‐day fetal and maternal New Zealand rabbit lungs. The concentration of total phospholipids in lamellar bodies increased four to five fold from 28‐day fetus to 30‐day fetus which, in turn, was similar to the maternal level. Total phospholipid content increased only about 50% in mitochondria and microsomes. The percentage of phosphatidyl choline among total phospholipids in lamellar bodies increased successively from 60% at 28 days gestation to 84% at 30 days gestation and leveled at 84% in maternal lamellar bodies. Microsomal PC increased steadily from 52% in the 28‐day fetus to 65% in the adult. Analysis of the fatty acid composition of phosphatidyl choline in lamellar bodies confirmed 16∶0 as the major fatty acid, and its content remained constant from 28 days gestation to adult. In contrast, the content of 16∶0 of the microsomal phosphatidyl choline decreased with increasing gestation. Changes of several unsaturated fatty acid components were observed in both lamellar bodies and microsomes in the developing lungs. Maturational development of phosphatidyl choline is reflected in an increase in the concentration of this surfactant, particularly in lamellar bodies, and possibly in remodeling of fatty acid composition in both lamellar bodies and microsomes.
Lipogenesis in the developing brain: Utilization of radioactive leucine, isoleucine, octanoic acid and β‐hydroxybutyric acid
Authors: Dhopeshwarkar Govind A. , Subramanian Carole 
Published: November 2006

AbstractIncorporation of radioactivity from intracranially injected radioactive leucine, isoleucine (ketogenic amino acids), octanoic acid and β‐hydroxybutyric acid into the brain lipids of 15 to 16 day‐old rats was examined. The results showed that radioactivity from all the above precursors was incorporated into brain lipids. Radioactivity from injected isoleucine was incorporated into odd numbered fatty acids indicating an alternate pathway to α‐oxidation for the biosynthesis of these fatty acids in the brain. For some as yet unclear reasons, a substantial portion of the radioactivity from injected octanoic acid was incorporated into free fatty acids. Utilization of these compounds for providing carbon for lipogenesis during development under unstressed normal conditions is discussed.
Isolated brain capillary endothelia: Influence of various levels of essential fatty acids on the acyl group composition of glycerophospholipids
Authors: Selivonchick Daniel P. , Roots Betty I. 
Published: November 2006

AbstractOn day seven of gestation, Wistar rats were assigned to a high essential fatty acid (EFA), low EFA, or a fat free diet. The same diets were continued during lactation. On weaning, the offspring were fed the same diets as their mother. Rats were killed at 222 days, brain capillary endothelia isolated, and total lipids extracted from the purified capillaries. The composition of the constituent fatty acids of ethanolamine glycerophospholipid (EGP), choline glycerophospholipid (CGP), and the alk‐1‐eny EGP composition from each diet is reported. A decrease in dietary EFA led to reduced proportions of total saturated acyl groups in EGP with no change observed in the total saturated acyl groups from CGP, and an increase in monoenoic fatty acids, particularly 18∶1n−9 for each phospholipid class. The proportions of 20∶4n−6 in alk‐1‐enyl EGP were reduced in fat‐free fed animals. In addition, the relationship between 20∶3n−9 and 20∶4n−6 fatty acids in brain capillary endothelia were markedly increased with a reduction in dietary fat. Low EFA and fat deficient animals showed a tendency to sequester 22∶6n−3.
Correlation in the proportion of oleic to vaccenic acid of plasma phospholipids with the early stages of hepatoma 7288CTC growth
Authors: Mapes James P. , Wood Randall 
Published: November 2006

AbstractThe major octadecenoate isomers, oleate (Δ9) and vaccenate (Δ11), were measured in the plasma phospholipids of rats bearing hepatoma 7288CTC as the tumor developed. The percentage of vaccenate decreased from 45% of the octadeceoate fraction at day zero to 25% by the 15th day. A significant decrease (45% to 35%) in the percentage of vaccenate occurred by the sixth day, well in advance of detectable tumor growth. The percentage of vaccenate continued to decrease as a function of time until day 15, after which it remained constant. Detection of alterations in plasma phospholipids at an early stage of tumor development in rats suggests that experiments should be carried out to determine if the same effects occur in humans.
Identification of thetrans isomers of octadecenoic acid in human milk
Authors: Picciano Mary Frances , Perkins Edward G. 
Published: November 2006

AbstractThe presence oftrans octadecenoic acid isomers was detected and analyzed in 24 hr pooled samples of human milk. Amounts of thetrans isomers of the C18 monoenes ranged from 2% to 4% of the total fatty acids. For purposes of comparison, three commonly used brands of infant formula were also analyzed and found to contain 0.1% to 1.3% oftrans monoene isomers. Data indicate that breast‐fed and bottle‐fed infants are receiving minimal levels oftrans fatty acids via milk.
Gangliosides of cultured cells of a rat mammary carcinoma cell line
Authors: Keenan T. W. , Schmid Erika , Franke Werner W. 
Published: November 2006

AbstractGanglioside content of rat mammary carcinoma‐derived cells grown in layers in vitro was nearly as high as that of apical plasma membrane‐derived milk fat globule membrane and nearly four times higher than the content of normal, lactating mammary tissue on a protein basis. The major ganglioside of these carcinoma‐derived cells was identified as GDla (sialic acid‐Gal‐GalNAc‐(sialic acid)‐Gal‐Glc‐Cer. Relative to carcinoma‐derived cells, rat mammary tissue and milk fat globule membrane had more complex ganglioside patterns but appeared to lack substantial quantities of GDla.
Lipid composition and biosynthesis of human omental tissue
Authors: Rabinowitz Joseph I. , Askins Sarvertia E. , Luddy Francis E. 
Published: November 2006

AbstractTwo groups of five males each were selected for total lipid analyses of their omental tissue. One of these groups had been subjected to a severe caloric restriction and had undergone total weight reduction of about 20%. The other group served as control. Both of these groups of patients required elective surgical procedures during which it was possible to obtain small samples of omental tissue, adipose pad, and/or mesenteric tissue. Total lipid analyses were performed on all of the materials. A distinctive positional distribution of the acyl groups was maintained in the triglycerides of omental tissue for all the patients regardless of dietary state. Patients under caloric restriction showed a reduction in their total triglyceride content, a reduction in their content of unsaturated fatty acyl groups, and a relative increase in phospholipid content. The de novo lipid biosynthetic capacity of omental tissues, as determined by 1‐[14C]‐acetate incorporation, showed an inverse proportionality to the lipid content of the samples. Omental tissue is biosynthetically a very versatile material capable of yielding rapidly many types of fatty acids. This ability, among others, could account for the usefulness of omental tissue as a supporting base in many types of restorative surgery.