bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metabolism of actinic skin tumors: Incorporation of14C‐acetate into lipids
Authors: Black Homer S. , Jones J. Scott , Lo Wan‐Bang 
Published: December 2006

AbstractBiochemical parameters of normal and actinically induced tumorous skin were compared. Similar respiratory rates and respiratory quotients were observed. However, both quantitative and qualitative differences occur in these tissue's ability to incorporate14C‐acetate into lipids.
Substitution reactions of linoleic acid hydroperoxide isomerase
Authors: Christianson D. D. , Gardner H. W. 
Published: December 2006

AbstractLinoleic acid hydroperoxide isomerase was extracted from corn germ and partially purified by differential centrifugation. This enzyme catalyzed the isomerization of linoleic acid hydroperoxide to the expected α‐ketol and γ‐ketol . Isomerase also catalyzed the substitution of various reagents at the carbon bearing the hydroperoxide group. These fatty acid products had the following functional groupings: where X is either oleoyloxy, ethylthio, or methoxy resulting from the presence of oleic acid, ethanethiol, or methanol, respectively. A crude wheat germ extract containing both lipoxygenase and isomerase enzymes reacted with linoleic acid to yield α‐ketols, γ‐ketols, and a substitution product, the linoleoyloxy ester of α‐ketol. Characterization of these products from wheat germ enzymes showed that the substitution reaction was not unique to corn germ. Because anions of the reagents tested are typical nucleophiles, the substitution reactions may proceed by a nucleophilic mechanism as mediated by the isomerase enzyme.
Effect of glucose administration on cholesterol and bile acid metabolism in rats
Authors: Uchida K. , Takeuchi N. , Yamamura Y. 
Published: December 2006

AbstractGlucose administered to fasted rats caused a marked stimulation in hepatic cholesterogenesis and cholesterol 7α‐hydroxylation, and an increase in biliary excretion of cholesterol and total bile acids. The excretion of cholic acid was not influenced during the first few hr after glucose administration, but was significantly increased after 5 hr. Chenodeoxycholic acid showed a similar change, but the increase was only ca. one tenth of that of cholic acid. The excretion of deoxycholic acid was markedly increased by 1 hr, but gradually decreased thereafter. Pretreatment with neomycin abolished the increase in deoxycholic acid by fasting and glucose administration. Other bile acid components showed no significant change. It thus was presumed that cholesterol endogenously synthesized in the liver was metabolized mainly to cholic acid. In contrast, exogenous cholesterol was metabolized mainly to chenodeoxycholic acid. During the period of the acute enhancement of cholic acid formation from the endogenous cholesterol, biliary excretion of deoxycholic acid was increased. This probably occurred through the depression of 7α‐rehydroxylation of deoxycholic acid, or through the enhancement of microbial formation of deoxycholic acid in the lumen, and through the increase of intestinal absorption.
Occurrence of 7‐methyl‐7‐hexadecenoic acid, the corresponding alcohol, 7‐methyl‐6‐hexadecenoic acid, and 5‐methyl‐4‐hexadecenoic acid in sperm whale oils
Authors: Pascal J. C. , Ackman R. G. 
Published: December 2006

AbstractTwo sperm whale oils from the northern hemisphere and two from the southern hemisphere were fractionated. Triglyceride and wax esters were examined for fatty acids and alcohols with monoethylenic unsaturation bearing a methyl branch on an ethylenic carbon. The 7‐methyl‐7‐hexadecenoic acid (0.37–1.37%) was accompanied by the corresponding alcohol (0.28–0.72%), but these materials were not accompanied by shorter chain homologues. The 7‐methyl‐6‐hexadecenoic acid was relatively less important (0.23–0.68%), but was accompanied by 5‐methyl‐4‐hexadecenoic acid (0.10–0.39%), and a partially identified C13 compound. Chromatographic properties on silver nitrate impregnated silicic acid TLC and on three GLC liquid phases are reported.
Role of cytidine triphosphate and cytidine diphosphate in promoting inositol entry into microsomal phosphatidylinositol
Authors: Holub B. J. 
Published: December 2006

AbstractThe Mn2+ activated incorporation of myo‐inositol‐3H into subfractions of phosphatidylinositol in rat liver microsomes was studied in the presence and absence of cytidine triphosphate or cytidine diphosphate choline using phosphate buffer. The distribution of labeled inositol among molecular species of microsomal phosphatidylinositol was also investigated in vivo. In other experiments, the release of radioactivity from microsomes labeled with inositol‐3H in the phospholipid was measured after the addition of Mn2+, unlabeled inositol, and cytidine nucleotide. Similar chase experiments were conducted with microsomes containing phosphatidylcholine‐14C or phosphatidyl‐ethanolamine‐14C. The addition of cytidine triphosphate or cytidine diphosphate choline stimulated the rate of inositol‐3H entry into microsomal phosphatidylinositol by 3.5 to 4‐fold and the monoenoic plus dienoic, trienoic, tetraenoic, and polyenoic species contained 6–7, 6, 78–81, and 7–9%, of the radioactivity, respectively. These latter patterns were very similar to those observed among the corresponding molecular species when the Mn2+ stimulated entry of free inositol into phospholipid was studied in the absence of added cytidine nucleotide. In chase experiments, the release of radioactivity from phospholipid in the presence of cytidine triphosphate or cytidine diphosphate choline was greatly enhanced by the addition of free inositol when microsomes containing phosphatidylinositol‐3H, but not phosphatidylcholine‐14C or phosphatidyl‐ethanolamine‐14C, were employed. Therefore, under the present conditions, cytidine triphosphate and cytidine diphosphate choline appear to stimulate the entry of inositol into phosphatidyl‐inositol by enhancing the Mn2+ activated exchange reaction in rat liver microsomes. The results suggest further that phosphatidylinositol is the preferred substrate when this reaction is stimulated by cytidine nucleotide.
Response of lipogenesis and fatty acid synthetase to physical training and exhaustive exercise in rats
Authors: Askew E. W. , Barakat H. , Kuhl G. L. , Dohm G. L. 
Published: December 2006

AbstractThe effect of physical training and exhaustive exercise on fatty acid synthesis in rat liver and adipose tissue has been investigated. Exercise training (treadmill running) significantly (P<0.05) decreased body wt, epididymal fat pad wt, adipocyte size, and hepatic fattya cid synthetase activity. Training did not significantly affect adipose tissue cell number, lipogenesis from glucose‐U‐14C, or fatty acid synthetase. Exercise to exhaustion immediately prior to sacrifice significantly (P<0.05) decreased lipogenesis from glucose‐U‐14C and fatty acid synthetase in adipose tissue from trained but not untrained rats. Liver fatty acid synthetase was not significantly influenced by exhaustive exercise. The results of this study indicate that rats may adapt to physical training by decreasing adipose tissue lipogenesis during exhaustive exercise. This adaptation in energy metabolism may facilitate physically trained animals in conserving blood glucose during exhaustive exercise, thereby prolonging endurance.
Aliphatic hydroxylamines as lipid antioxidants
Authors: van der Veen J. , Weil J. T. , Kennedy Theresa E. , Olcott H. S. 
Published: December 2006

AbstractIt was previously noted that N,N‐dioctylhydroxylamine is formed from the oxidation of trioctylamine in oxidizing fats and that N,N‐dioctyl‐ and N,N‐diethylhydroxylamine preparations have antioxidant activity. In this paper we summarize some additional observations with these and some other N‐substituted hydroxylamines. ESR spectra indicate that nitroxides are present in oxidized preparations of hydroxylamines. Since some stable nitroxides have been shown to be exceptionally effective antioxidants, we hypothesize that the antioxidant effectiveness of the hydroxylamines is accounted for by their conversion to nitroxides during the inital stages of oxidation.
Phylogeny of lipase specificity
Authors: Berner David L. , Hammond Earl G. 
Published: December 2006

AbstractLipase preparations from 19 animal species, representing nine of the animal phyla, were studied. Acetone powders were prepared from the pancreas, hepatopancreas, gastrointestinal tract or whole animal, and the preparations were screened for lipolytic activity by tributyrin agar clearing. The pH optimum of each preparation was determined by using both tributyrin and corn oil emulsions. The positional specificity at the pH optimum of each lipase preparation was determined from the fatty acids released by a 2–5 min reaction with cocoa butter and lard. The vertebrate lipases behaved analogously to hog pancreatic lipase by showing a high specificity for the 1 and 3 positions of long chain triglycerides. Invertebrate preparations that did hydrolyze long chain triglycerides did so randomly, with no strong positional or fatty acid specificity.
Specificity of lipase from several seeds andLeptospira pomona
Authors: Berner D. L. , Hammond E. G. 
Published: December 2006

AbstractThe specificities of lipase preparation from oats,Leptospira pomona DM2H, corn, soybeans, safflower seed and pinion nuts were examined by using cocoa butter, lard and corn oil as substrates. Oat lipase exhibited an acyl group specificity, favoring the hydrolysis of linoleyl groups and discriminating against stearoyl groups. TheL. pomona lipase exhibited a tendency to hydrolyze acyl groups on the 1 and 3 positions of glycerol preferentially. The hydrolysis by the other seed lipases was nonspecific.
Phospholipid complexes with molybdate
Authors: Galanos Dimitris S. 
Published: December 2006

AbstractPhosphorus‐containing organic‐compounds combine directly with molybdate to form complexes analogous to phosphomolybdate. These complexes are extractable by organic solvents such as ethyl acetate or butanol. The ability of chloroform‐ethanol mixtures in extracting only the phospholipid‐molybdate complexes but not those of water‐soluble phosphates may find some useful applications.
On the biosynthesis of glycerol ethers in mitochondria
Authors: Anderson Robert E. , Sansone Gail L. 
Published: December 2006

AbstractMitochondria from mouse preputial glands incubated with 1‐14C‐myristic acid and appropriate co‐factors produced, after LiAlH4 reduction, a compound that resembled a glycerol ether. However, close examination of this material showed that it was not an ether, and we tentatively identified the original compound as a phosphorylated β‐keto (or β‐hydroxy) fatty acid.
Pancreatic lipolysis of enantiomeric triglycerides
Authors: Jensen R. G. , Pitas R. E. , Quinn J. G. , Sampugna J. 
Published: December 2006

AbstractPancreatic lipase hydrolyzed fatty acids in equimolar quantities from thesn‐1‐ and 3‐positions of three synthetic enantiomeric triglycerides, two of which could make a racemic pair. The monoglycerides from digestions of five enantiomeric triglycerides were at least 99% representative of the 2‐position. The data confirm that pancreatic lipase did not distinguish between thesn‐1‐ and 3‐positions and that with these triglycerides pancreatic lipolysis can be used to help establish structure.
Effect of alimentation on human serum squalene levels
Authors: Lewis R. W. 
Published: December 2006

AbstractFive subjects consumed a meal containing ca. 1.5 mg squalene. Postprandial serum samples showed that in three of the subjects squalene and lipid levels reached maxima at 3 hr. Squalene levels in the low density lipoproteins of these subjects also increased. The results indicate that alimentation is a major factor in the variation in serum squalene levels.
Lipids ofKlebsiella pneumoniae: The presence of phosphatidyl choline in succinate‐grown cells
Authors: Wassef Momtaz K. 
Published: December 2006

AbstractThe carbon and energy source for aerobically grown cultures ofKlebsiella penumoniae profoundly influenced the total lipid content and phosphatide composition. Glucose‐grown cells contained 13% lipid, 56% of which was phospholipids. Succinate‐grow cells contained 8% lipid, 66% of which was phospholipids. The predominant phosphatides of glucose‐grown cells were phosphatidyl ethanolamine, 82%; phosphatidyl glycerol, 4.5%; phosphatidic acid, 5%; cardiolipin, 6.5%; phosphatidyl serine; and trace amounts of unidentified phosphatides. Phosphatides of succinate‐grown cells were phosphatidyl ethanolamine, 38%; diphosphatidyl glycerol, 14%; phosphatidyl glycerol, 13%; phosphatidyl choline, 14.5%; phosphatidyl serine, 6%; phosphatidic acid, 4%; and 10% unknown lipids. No trace of phosphatidyl choline was found in glucose‐grown cells.
Autoxidation of polyunsaturated fatty acids: II. A suggested mechanism for the formation of TBA‐reactive materials from prostaglandin‐like endoperoxides
Authors: Pryor William A. , Stanley J. P. , Blair E. 
Published: December 2006

AbstractThe nature and mechanism of formation of the thiobarbituric acid (TBA)‐reactive material produced in the autoxidation of polyunsaturated fatty acids (PUFA) or their esters has been studied. On the basis of chemical studies and
Plasma transport forms of ingested fatty alcohols in the rat
Authors: Friedberg Samuel J. 
Published: December 2006

AbstractPrevious studies have shown that ingested fatty alcohols are absorbed as fatty acids and fatty acid esters, particularly triglycerides. The present study was carried out to determine whether fatty alcohols are also transported as 0‐alkyl glyceryl ethers, alk‐1‐enyl glyceryl ethers, and as wax esters. Oxidation of fatty alcohols to other lipids was assessed by using a mixture of [1‐3H] hexadecanol and [1‐14C] hexadecanol of predetermined ratio. The results indicate that the absorption of fatty alcohol, and of its transport forms, parallels the absorption of labeled fatty acids. Six to 25% of plasma radioactivity was present as 1‐0‐alkyl diacylglyceryl ethers with a smaller proportion of ether lipids in the phospholipid fraction. In addition, 4–13% of the ingested hexadecanol appeared in the plasma as a material having the chromatographic properties of wax ester. Fatty alcohols were not detected in the plasma as alk‐1‐enyl lipids.
Interactions of phospholipase D with 1,2 diacyl‐sn‐glycerol‐3‐phosphorylcholine, dodecylsulfate, and Ca2+
Authors: Heller Michael , Mozes Nava , Peri (Abramovitz) Irena 
Published: December 2006

AbstractSome properties of the pure, soluble phospholipase D (phosphatidycholine phosphatido hydrolase, EC 3.1.4.4) interactions with phosphatidyl choline (1,2 diacyl‐sn‐glycerol‐3‐phosphoryl choline) in a system also containing dodecylsulfate and Ca2+ ions were studied. Concentrations of Ca2+ greater than 50 mM were necessary both for activity and adsorption of the enzyme to the “supersubstrate.” Ethylenediamine tetraacetic acid caused inhibition of activity, greater than one would expect from its chelating capacity. A nonlinear increase in activity with the increase of enzyme protein was observed, suggesting a subunit aggregation into a higher mol wt protein, catalytically more active. Upon centrifugation of the supersubstrate‐enzyme complex at 4.5×105g·min at 30 C, most of the substrate molecules sedimented regardless of the pH. The reverse was true when centrifugation was done at 1 C. Phospholipase D hydrolyzed phosphatidylcholine molecules present in the supersubstrate at temperatures around 0 C at a rate 1/5 that of a maximal value measured at 30C. The Arrhenius plot was linear in the range from 0 to 30 C, and at that temperature the curve broke with a smaller slope. Activation energy of 9.1 Kcal/mol, below 30 C, was calculated. Adsorption of the enzyme to the sedimentable supersubstrate occurred at pH 8.0, regardless of temperature. At pH 5.6, a considerable portion of phosphatidylcholine was degraded at 30 C, thus minimizing the capacity of the supersubstrate to adsorb the enzyme. Although Mg2+ could replace Ca2+ in the formation of sedimentable supersubstrate, it neither assists in adsorption of the enzyme nor in activation of the phosphatidylcholine hydrolysis.
Metabolism of 2,4‐3H‐14α‐methyl‐5α‐ergost‐8‐enol and 2,4‐3H‐5α‐ergosta‐8,14‐dienol inOchromonas malhamensis
Authors: Adler John H. , Patterson G. W. 
Published: December 2006

AbstractTritium‐labeled 14α‐methyl‐5α‐ergost‐8‐enol and 5α‐ergosta‐8,14‐dienol were converted to brassicasterol and poriferasterol inOchromonas malhamensis. This indicates that the organism can rearrange these sterol structures so that they contain the naturally occurring 5(6) double bond, and suggests thatO. malhamensis is able to introduce a 24(28) double bond into a nine‐carbon saturated side chain which is alkylated to produce a C‐29 sterol.
Lipid absorption in the young of protein‐deficient rats
Authors: Zeman Frances J. , Fratzke Marilyn L. 
Published: December 2006

AbstractThe effect of reduced protein in the diet during pregnancy on the subsequent absorption of triolein and of oleic acid which were infused into the intestine of the young was studied. Pregnant rats were fed diets containing either 24% or 4% casein as the sole source of protein. Control and prenatally protein‐deprived (PPD) young were studied at birth, before and after suckling, and at 4, 8, and 12 days. Both body weight and the weight and length of intestine were reduced in PPD young. Uptake of triolein from the lumen and retention in enterocytes increased on suckling in newborn control pups, but the amount transferred from or metabolized by the cells did not change. In suckled PPD young, transfer of triolein increased through the enterocyte as well. Unsuckled PPD pups had reduced absorption and retention per enterocyte, per g body weight, per cm gut, and in total. In intestines of control and PPD suckled newborn and postnatal pups, absorption per cell did not differ. Blood lipid levels were increased markedly between 0 and 4 days and tended to decrease to newborn levels by 12 days in both diet groups. Oleic acid absorption in newborn and 12‐day PPD pups were reduced in total, per g body weight and per cm of gut. The individual enterocytes were shown to be equally capable of absorption and transfer of triolein and oleic acid. Differences in absorption are related primarily to the numbers of absorptive cells.
Effect of dietary fats on ovine adipose tissue metabolism
Authors: Vernon R. G. 
Published: December 2006

AbstractThe effects of different dietary fats on ovine adipose tissue metabolism have been investigated. Six‐month old sheep were fed for 6 weeks a control diet or diets supplemented with either tallow or a mixture of sunflower seed oil and soybean oil, treated to protect the fats from hydrolysis and hydrogenation in the rumen, or with maize oil. The rates of fatty acid, glyceride glycerol, and CO2 formation were measured in perirenal and subcutaneous adipose tissue slices by following the incorporation of either14C from labeled acetate or glucose, or3H from tritiated water into the appropriate product. Feeding protected tallow or maize oil but not protected sunflower seed oil plus soybean oil resulted in reduced rates of fatty acid biosynthesis in both perirenal and subcutaneous adipose tissue slices and CO2 formation in perirenal adipose tissue. Feeding the fat‐supplemented diets had no effect on the rate of glyceride glycerol formation. The fat‐supplemented diets also resulted in reduced activities of various enzymes, thought to be involved in lipogenesis, measured in 105,000× g supernatant fractions from adipose tissue homogenates. The results suggested that ovine adipose tissue lipogenesis is sensitive to both the amount and the nature of dietary fat.
In vitro biosynthesis of prostaglandin E2 by kidney medulla of essential fatty acid deficient rats
Authors: Kaa Elisabet 
Published: December 2006

AbstractWeanling rats were fed either a semi‐synthetic diet with no fat, with 28% by wt partially hydrogenated fish oil, or with 28% by wt arachis oil (control diet) for 6 or 71/2 months. The in vitro conversion of arachidonic acid to prostaglandin E2 by homogenates of the rat kidney medulla was measured by gaschromatography with electron capture detection. The kidney medulla of essential fatty acid deficient animals showed increased activity for the in vitro conversion of exogenous arachidonic acid to prostaglandin E2 when compared to the controls. The change of the enzymatic activity in the essential fatty acid deficient animals was reversible, as shown by refeeding. Inhibition of the prostaglandin synthetase was found at exogenous substrate concentrations higher than 50–100 μM.
Lipid composition of rat sciatic nerve
Authors: Klein F. , Mandel P. 
Published: December 2006

AbstractIn the course of our study on the lipids of the rat sciatic nerve, the analysis of the neutral lipids allowed us to detect and characterize cholesteryl esters present at a relatively high level (5%). Among the phospholipids, ethanolamine phosphoglyceride is the most abundant fraction and contains nearly all the plasmalogens (20% of total lipid phosphorus). The glycolipids consist of five different fractions; the cerebrosides with hydroxy fatty acids account for 38% of total glycolipids. Monogalactosyl diglyceride represents 7% of total glycolipids.
Sensitive fluorometric method for tissue tocopherol analysis
Authors: Taylor Steve L. , Lamden Merton P. , Tappel AL. L. 
Published: December 2006

AbstractA sensitive, highly reproducible method for tissue tocopherol analysis that combines saponification in the presence of large amounts of ascorbic acid to remove interfering substances, extraction of the nonsaponifiable lipids with hexane, and fluorometric measurement of the tocopherol is presented. The nonsaponifiable lipid phase contained only one fluorochrome in the 290 nm excitation and 330 nm emission range, and it was identified as tocopherol by thin layer and column chromatography. Column chromatography of the hexane extract of a saponified,14C‐tocopherolspiked microsomal fraction showed that no measurable oxidation to tocopherylquinone has occurred. The fluorometric method for tocopherol analysis was applied to homogenates and subcellular fractions from rat liver, kidney, lung, and heart and red blood cells. The heavy mitochondrial and microsomal fractions had the highest subcellular concentrations of tocopherol.
Low and moderate concentrations of lysobisphosphatidic acid in brain and liver of patients affected by some storage diseases
Authors: Kahma Kauko , Brotherus Jaakko , Haltia Matti , Renkonen Ossi 
Published: December 2006

AbstractThe relative amount of lysobisphosphatidic acid (LBPA), known also as bis(monoacylglyceryl)phosphate, among the total phospholipids was analyzed in post mortem samples of brain and liver of patients affected by four storage diseases. In spite of the extensive accumulation of storage lysosomes, none of the samples revealed a highly elevated LBPA content comparable to that found in the liver in Niemann‐Pick disease and in the liver in lipidosis induced by 4,4′‐diethylaminoethoxyhexestrol. We conclude that, although LBPA is often present in high concentration in lysosomes of many types of cells, it is not always a major component of these organelles.
Study of bound phospholipase activities of fungal mycelia using an organic solvent system
Authors: Blain J. A. , Patterson J. D. E. , Shaw C. E. , Akhtar M. Waheed 
Published: December 2006

AbstractIt has been possible to demonstrate and characterize high phospholipase activities in mycelia ofRhizopus arrhizus andMucor javanicus by use of a system in which substrates were dissolved in diisopropyl ether. Such activities were associated with bound enzymes and would have been difficult to detect using aqueous assay systems. In both cases, phosphatidylcholine hydrolysis was by phospholipase A1 (EC 3.1.1.32) activity followed by the action of lysophospholipase (EC 3.1.1.5). Phospholipase D (EC 3.1.4.4) activity was also detected. The methods used appear to be of general applicability for the detection and study of insoluble phospholipases.