bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of dietary di‐2‐ethylhexyl phthalate on lipid biosynthesis in selected tissues from the rat, in vitro
Authors: Bell Frank P. , Nazir Darius J.
Published: November 2006

Di‐2‐ethylhexyl phthalate (DEHP), a plasticizer commonly used in the production of polyvinyl chloride plastics, has become an environmental pollutant. At the present time, the biological significance of phthalates in the environment is unknown. In the present studies, we observed that addition of DEHP to a stock diet of rats resulted in marked effects on incorporation of14C‐acetate into lipid by liver and kidney slices; other organs, such as heart, testes, and aorta were unaffected. Incorporation of14C‐acetate into total lipid of liver (dpm/mg wet wt) from rats, fed 0.5% or 1.0% DEHP for 10 or 18 days, respectively, was decreased to ca. 50% of control values. The decreased incorporation into liver lipid is not attributable to any one lipid fraction, inasmuch as incorporation into the phospholipid, sterol+diglyceride, free fatty acid, triglyceride, and sterol ester+hydrocarbon fractions was decreased 30–70% with respect to controls. In addition, the percent distribution of14C‐acetate among the individual phospholipids was ca. 25% lower in phosphatidyl choline of the DEHP‐fed rats. In rats fed 0.5% DEHP, incorporation of14C‐acetate into total lipid of kidney was similar to control values, but incorporation into the triglyceride and sterol ester+hydrocarbon fraction was decreased 30–40%, whereas incorporation into the sterol+diglyceride fraction was increased 38%. Livers from DEHP‐fed rats were ca. 20% larger than livers from control rats and, at the 0.%% level of DEHP feeding, testes wts were elevated; no significant changes were noted in wts of spleen, heart, aorta, kidney, or body wt gains in rats fed DEHP. These studies emphasize a subtle toxicity of phthalate esters not previously reported and emphasize the need for further biochemical studies to evaluate the effect of phthalates on biological systems.
13C nuclear magnetic resonance spectroscopy of saturated, unsaturated, and oxygenated fatty acid methyl esters
Authors: Tulloch A. P. , Mazurek M.
Published: November 2006

Chemical shifts have been assigned to all the separate signals in the13C nuclear magnetic resonance spectra of methyl stearate, oleate, and petroselinate by means of the second and third atom isotope effects in spectra of specifically deuterated esters. Spectra of almost all the isomeric hydroxy, acetoxy, and oxo stearates were also measured. From the assignments, the effects of the introduction of a double bond or an oxo, hydroxy, or acetoxy group at different positions on the fatty acid chain on the13C nuclear magnetic resonance spectra were determined. All the isomeric oxo stearates and most of the hydroxy and acetoxy stearates can be distinguished and identified by their13C spectra.
Linoleic acid amides: Effect on cholesteremia and atherosclerosis
Authors: Kritchevsky David , Tepper Shirley A. , Story Jon A.
Published: November 2006

Several of a series of linoleic acid amides have been reported to inhibit cholesterol‐induced atherosclerosis in rabbits. The three amides which have been studied to the greatest extent are (in order of increasing activity) N‐cyclohexyl linoleamide (AC23), N(α methylbenzyl) linoleamide (AC223), and N[α‐phenyl‐β‐(p‐tolyl) ethyl] linoleamide (AC485). We have found AC223 to inhibit cholesterol absorption in rats and to slightly inhibit exogenous but not endogenous cholesteremia in rabbits. In a fiber‐free diet, AC223 reduces serum cholesterol and liver triglyceride levels. Rats were also fed a basal semipurified diet with and without AC223. Fecal excretion of labeled exogenous (as [14C] cholesterol) or endogenous (as [14C] mevalonolactone) steroid was 44 and 43% higher in drug treated groups. The mechanism of hypocholesteremic action of the linoleamides appears to involve inhibition of cholesterol absorption.
Response to the hypobetalipoproteinemic agent adamantyloxyphenyl piperidine in hyperlipemic rats
Authors: Schurr Paul E. , Day Charles E.
Published: November 2006

The hypobetalipoproteinemic activity of U‐41, 792 (1‐[p‐(1‐adamantyloxy)‐phenyl]‐piperidine) is a marked and selective reduction of heparin precipitating lipoproteins (low density plus very low density lipoproteins) in cholesterol‐cholic acid induced hypercholesterolemic rats. This activity consists of both a reduction in heparin precipitating lipoproteins (HPL) and an increase in high density lipoproteins that are not precipitated by heparin. The increase in high density lipoproteins is routinely noted by decreases in HPL/cholesterol ratios. The pattern of response following single 100 mg/kg doses of U‐41, 792 was determined. After an I.V. dose was administered in a cotton‐seed oil emulsion, serum cholesterol levels were reduced, beginning at 8 hr after administration and persisting for 96 hr. Similar results, though delayed somewhat, were obtained after a single oral dose. Activity was accompanied by increases in weight and cholesterol content of livers. After multiple, daily, oral doses, liver weights, total lipids, and cholesterol contents were reduced. Hypobetalipoproteinemic activity was enhanced by prolonged treatments as demonstrated by analyses of serum obtained weekly throughout 7 wk.
Uptake and metabolism of fatty acids by Soybean suspension cells
Authors: Stumpf P. K. , Weber N.
Published: November 2006

Soybean suspension cultures very rapidly take up C16 and C18 fatty acids by a nonspecific, nonenzymic binding of exogeneously added fatty acids to cell walls and by a subsequent transfer into the cell where they are rapidly incorporated into triacylglycerols, phosphatidylcholines, and phosphatidylethanolamines.14C‐Palmitic and14C‐stearic acids follow this sequence but are not desaturated, wherease14C‐oleic and14C‐linoleic acids are transferred more rapidly than the saturated fatty acids and are then further modified. All the data fit a sequence of events by which free oleic acid is first activated to a CoA thioester, and then desaturated to linoleyl‐CoA; both thioesters are then transferred to triacylglycerols, phosphatidylcholine, and phosphatidylethanolamine.
Relationships between base‐exchange reaction and the microsomal phospholipid pool in the rat brain in vitro
Authors: Gaiti Alberto , Brunetti Marina , Woelk Helmut , Porcellati Giuseppe
Published: November 2006

The calcium‐stimulated incorporation of ethanolamine, choline and L‐serine into rat brain microsomal phospholipids has been investigated. The membranes were prelabeled in vitro in their choline or serine phosphoglycerides by base‐exchange and then chasing experiments were done by displacing the lipid‐bound base by ethanolamine, choline, or L‐serine labeled with a different isotope. The results indicate that membrane phosphatidylcholine is presumably a substrate for the exchange with all the three bases, whereas phosphatidylserine exchanges only with ethanolamine and L‐serine but not with choline. A small phospholipid pool (3–7% of the total available pool) is active in the calcium‐dependent exchange with choline, ethanolamine, and L‐serine. When the microsomal membranes are prelabeled in vitro in their phosphatidylcholine moiety through the cytidine‐dependent pathway and then chasing experiments are performed with the three nitrogenous bases, as above, the small phospholipid pool is hardly detectable. In view of these and other results (Gaiti et al., FEBS Letters 49:361 1975), it is suggested that at least two different pools of phosphatidylethanolamine, phosphatidylserine, and phosphatidylcholine might exist in rat brain microsomes.
Fatty acids of the seed oils of alpineCruciferae and other alpine species
Authors: Scrimgeour Charles M.
Published: November 2006

A fewCruciferae seed oils do not contain erucic acid but are instead rich in linolenic acid. These oils are characteristic of alpine species, and the fatty acid composition of such oils may be an adaption to an alpine habitat.
Phospholipids of human serum
Authors: Williams J. H. , Kuchmak M. , Witter R. F.
Published: November 2006

Phospholipids extracted from normal human serum were fractionated into lecithin, lysolecithin, sphingomyelin, phosphatidyl ethanolamine, lysophosphatidyl ethanolamine, phosphatidyl serine, and phosphatidyl inositol. Identification of each was established by thin‐layer chromatography and infrared spectrophotometry. The content of plasmalogen was determined in both lecithin and phosphatidyl ethanolamine fractions. The composition of fatty acids and fatty aldehydes in isolated phospholipids is presented. The degree of unsaturation as reflected in the average content of double bonds per molecule of the fatty acids in phospholipids was: lecithin 1.2, choline plasmalogen 2.1, lysolecithin 0.6, sphingomyelin 0.2, phosphatidyl ethanolamine 2.8, lysophosphatidyl ethanolamine 1.0, phosphatidyl serine 1.0, and phosphatidyl inositol 1.8. Both chlline and ethanolamine plasmalogen aldehydes were predominantly saturated. Molecular weight of each phospholipid was calculated from determined fatty acid and fatty aldehyde compositions; the phosphorus factor for each phospholipid was computed. On a weight percent basis, lecithin, sphingomyelin, and lysolecithin accounted for 95% of the total phospholipids. The ethanolamine‐containing phospholipids accounted for 2.5%, and the remainder was divided among phosphatidyl inositol, choline plasmalogen and phosphatidyl serine.
Influence of temperature on the fatty acid pattern of mosquitofish (Gambusia affinis) and guppies (Lebistes reticulatus)
Authors: Knipprath Werner G. , Mead James F.
Published: November 2006

Adult male mosquitofish were adapted to 14–15C and 26–27C water temperature over a 14‐day period and the fatty acids from their total lipids analyzed by gasliquid chromatography.

Newly born guppies were raised at the same temperature for eight weeks and analyzed in the same way. Some fish in the warm water group were subjected to a sudden drop in temperature and the changes of the fatty acids studied after two and eight days, and after two and four weeks.

In all fish the tendency is toward higher unsaturation at lower temperature, but the acids involved in the change differ with the species of fish. A distinct difference is also obvious when guppies are raised at, or when they are adapted to the low temperature. The diet, too, influences the kind and amount of fatty acid synthesis and deposition.
Absorption of Di‐ and triglycerides by intestinal slices in vitro
Authors: Feldman Elaine Bossak , Borgström Bengt
Published: November 2006

The uptake by hamster intestinal rings of labeled 1,3‐diolein and triolein in bile salt emulsions was studied.

About 6% of triolein was taken up from emulsions containing glycerides and fatty acid in 6 mM sodium taurodeoxycholate. Lesser uptake was noted when triolein was emulsified with lecithin, cholesterol and bile salt; lowest uptake (3%) was observed from triolein‐lecithincholesterol emulsions prepared without bile salt.

Absorption of 1,3‐diolein from bile salt emulsion was greater and acylation to triglyceride was observed.

Diglycerides and triglycerides in small quantity may be absorbed intact from a micellar phase.
Characterization of fatty acids from root and shoot lipids ofCapsicum species
Authors: Lyons James M. , Lippert L. F.
Published: November 2006

Lipids were extracted from the roots and shoots of four species of theCapsicum (pepper) genus and separated into three fractions: triglycerides; free fatty acids, mono‐ and diglycerides; and phospholipids. The component fatty acids were determined by subjecting the methyl esters to gasliquid chromatography. The predominate fatty acids obtained were palmitic (16∶0) and linoleic (18∶2), with lesser amounts of linolenic (18∶3), stearic (18∶1), and oleic (18∶0). Differences existed in the neutral lipid fractions which might be of value from taxonomic interests; however, the phospholipids from each of the species and plant parts did not differ so greatly. A comparison of the amount of unsaturated fatty acids in the phospholipid fractions indicates that differences exist which might be of value in determining the relative sensitivity of the several species to chilling temperatures.
Long‐chain fatty acids containing ether linkage. I. The antibacterial and fungicidal activities of some new β‐alkyloxypropionic acids and their methyl esters
Authors: Abe Yoshiro
Published: November 2006

β‐Alkoxypropionic acids and their methyl esters were made with alkoxy groups ranging from C4H9O to C18H35O: R‐O‐CH2CH2COOH (CH3). Methyl esters and acids were also made with one and with two oxyethylene groups between the alkoxy group and the propionic acid group: RO (CH2 CH2 O) n‐CH2CH2 COOH(CH3). The compounds were tested againstStaphylococcus aureus and againstPenicillium for growth inhibition. The optimum size of the alkoxy group appears to be R=C12H25. Oxyethylene groups enhanced the activity againstS. aureus, but had relatively little effect againstPenicillium.
Lipid binding in mitochondria from testes of normal and essential fatty acid deficient rats
Authors: Hølmer G. , Tronier B.
Published: November 2006

Essential fatty acid (EFA) deficiency in rat causes severe degeneration of spermatogenic tissue. Previously it was shown that the distribution of lipid classes changes very little during tissue degeneration. However it is well known that the fatty acid spectrum in lipids from testicular tissue is altered drastically during EFA deficiency. The molecular binding of lipids in membrane structures might be altered when a larger amount of ω9‐acids is present in the various lipid classes in testes of EFA‐deficient rats. In the present studies comparison was made of the binding of lipids in testicular mitochondrial membranes from rats fed a fat‐free diet or a diet containing 6% peanut oil for 26 weeks. Isolated mitochondria were coated on glass beads, then dried and packed into a column, whereafter the membrane lipids were eluted with solvents with increasing dielectric constants. The differences between the binding of lipid classes in supplemented and EFA‐deficient rats were not pronounced, but a tendency to a weaker binding in the EFA‐deficient rats was observed. However for both groups the various extracts showed marked differences in the distribution of lipid classes concurrent with the change of the eluent. This indicates a different kind of binding in the membrane, not only for different lipid classes, but also within a special lipid class. Thus both phosphatidylcholines (PC) and phosphatidylethanolamines (PE) were found in extracts with quite different dielectric constants. The fatty acid composition of PC and PE in the major fractions eluted with chloroform and ethanol, respectively, was essentially the same. This indicates that the successive release of phospholipids (PL) in these two fractions was not based on fatty acid solubility properties but on variable binding in the membrane structure. The introduction of ω9‐polyenoic fatty acids instead of ω6‐polyenoic fatty acids in the PL of mitochondria membranes from EFA‐deficient rats seems to be the only deviation in the lipid pattern of EFA‐supplemented and EFA‐deficient animals, and might therefore be responsible for the symptons of EFA deficiency.
Fluorescent modification of serum albumin by lipid peroxidation
Authors: Fletcher B. L. , Tappel A. L.
Published: November 2006

Peroxidation of fatty acids bound to human serum albumin results in the production of fluorescent chromophores in the protein when it is stored in the liquid, powdered or crystalline state. Peroxidizing polyunsaturated fatty acid esters, and carbonyls derived from peroxidizing lipids react with amino groups of protein to give products that have fluorescence spectra very similar to those observed for stored commercial preparations of serum albumin.
Lipid metabolism ofAgaricus bisporus (Lange) sing.: I. Analysis of sporophore and mycelial lipids
Authors: Holtz R. Barry , Schisler Lee C.
Published: November 2006

The lipid components of four strains ofAgricus bisporus (Lange) Sing., the cultivated mushroom, were analyzed. Both sporophore and mycelial samples were obtained from beds in normal production. A method for obtaining mycelium free of compost was developed. Neutral lipids were separated from polar lipids by silicic acid column chromatography. Each fraction was separated by thin layer chromatography. Fatty acid methyl esters were analyzed by gas liquid chromatography and mass spectrometry. Sporophore extracts contained free sterol, free fatty acid, triglycerides, phosphatidyl choline and phosphatidyl ethanolamine. High amounts of linoleic acid were found in both neutral and polar lipid fractions. Mycelial extracts contained free fatty acids, triglycerides, phosphatidylcholine and phosphatidyl ethanolamine. No free sterol could be detected. Linoleic acid was also present in large amounts.
Chemical reactions at lipid‐gas interfaces: I. Terminal chain elongation of fatty acids
Authors: Johnson C. B. , Wilson A. T.
Published: November 2006

Reactions of free methyl radicals and monolayers of potassium palmitate and of potassiumn‐heptadecanoate on an aqueous surface yielded straight chain saturated fatty acids containing longer hydrocarbon chains than those of the reactant acids. Similar results were obtained from the reactions of free ethyl radicals and potassium palmitate under similar conditions. The results of this investigation indicate that extension of hydrocarbon chains by free radical addition reactions can be achieved if the growing chains are suitably packed in a monolayer on a surface.
Effect of bovine serum albumin on monoacyl‐ and diacylglycerol 3‐phosphate formation in mitochondrial and microsomal fractions of rabbit hearts
Authors: Zaror‐Behrens Gloria , Joe Kako K.
Published: November 2006

The formation of monoacyl‐ and diacylglycerol 3‐phosphate (P) by rabbit heart mitochondrial and microsomal fractions was studied by varying the concentration of acyl‐CoA and that of bovine serum albumin in the assay system. The two subcellular fractions were prepared by the conventional differential centrifugation technique. The optimal concentration of acyl‐CoA for both mitochondrial and microsomal acylation of glycerol 3‐P was shifted to a higher range of acyl‐CoA concentrations by greater amounts of albumin. A similar shift in the acyl‐CoA concentration‐enzyme activity relationship was observed in the acylation reaction of 1‐palmitoylglycerol 3‐P by the heart microsomes. The addition of albumin increased slightly the rate of diacylglycerol 3‐P accumulation but increased greatly the rate of monoacylglycerol 3‐P accumulation at any concentration of acyl‐CoA; the effect was observed with mitochondrial or microsomal fraction as the crude enzyme source. Moreover, palmitoyl‐CoA and linoleoyl‐CoA served equally well as the acyl donor for the acylation reaction. However, relatively more monoacyl‐ than diacylglycerol 3‐P was accumulated in the assays with rabbit heart mitochondrial fraction in the presence of albumin, whereas more diacylthan monoacyglycerol 3‐P was formed by the microsomal fraction. As a result, the microsomal diacyl: monoacyl‐glycerol 3‐P ratio was invariably greater than the mitochondrial ratio at a given concentration of acyl‐CoA and albumin.
Fatty acid variability of plasma lipids and cholesteryl esters in adult male twins and their brothers
Authors: Kang K. W. , Christian J. C. , Hedges B. , Corey L. A. , Powell R.
Published: November 2006

Variation in the fatty acid composition of fasting plasma lipids and of cholesteryl esters was studied in 69 sets of adult male twins and 25 of their brothers. Genetic variances were estimated using the twin model. In general, monozygotic (MZ) twins were characterized by the smallest within‐pair variance, and brothers of twins by the largest. Variation within dizygotic pairs fell intermediate to that of MZ twins and brothers. The present study did not reveal consistent significant (P<0.05) genetic variation in plasma fatty acids from total plasma lipids or cholesteryl esters.
Lipid content and fatty acid composition of heart and muscle of the BIO 82.62 cardiomyopathic hamster
Authors: Barakat Hisham A. , Lynis Dohm G. , Loesche Patricia , Tapscott Edward B. , Smith Carlton
Published: November 2006

Microscopic and analytical studies of the lipids in the heart and muscle of the BIO 82.62 myopathic hamsters and agematched normal animals at the average ages of 33, 67, and 108 days were performed. Microscopic examinations did not show increased lipid depositions in the hearts of the diseased animals as was found in the BIO 14.6 strain. No consistent differences in the lipid content of the cardiomyopathic hamsters (BIO 82.62) and age‐matched controls were observed in the three age groups except in the cholesterol content of muscle. Cholesterol increased significantly (P<0.01) in the 67 and 108 day old animals. This increase elevated the cholesterol/phospholipid ratio. Analysis of the fatty acid composition of triglycerides showed that the cardiomyopathic hamsters store more saturated fatty acids in both heart and muscle than do their normal counterparts. The abundance of more saturated fatty acids may imply that either the desaturation mechanism is altered in the diseased animals or that unsaturated fatty acids are preferentially utilized in other processes.
Determination of background serum density for lipoprotein ultracentrifugation
Authors: Jensen Gordon L. , Smith Samuel C.
Published: November 2006

It is necessary to know the density of serum exclusive of its macromolecules (background density) prior to density adjustment with solid potassium bromide for ultra‐centrifugal separation of lipoprotein fractions. To evaluate this, we compared the densities of the corresponding ultrafiltrates or dialysates of both human and equine sera produced by ultrafiltration and equilibrium dialysis methods for macromolecule removal. Excellent correlation is found between background densities determined following ultrafiltration or equilibrium dialysis. These data validate the use of ultrafiltration as a simple, direct method for determination of background serum densities but reveal equilibrium dialysis to be more time consuming and less precise. Using ultrafiltration, we find the background density for equine serum to be 1.004 g/ml, and initial investigation suggests this value may be altered by freezing, prolonged refrigeration (3 months), or heating to inactivate lecithin: cholesterol acyltransferase.
Lipid composition ofNeurospora crassa
Authors: Kushwaha S. C. , Kates M. , Kramer J. K. G. , Subden R. E.
Published: November 2006

The lipids ofNeurospora crassa, isolated in pure form from freeze‐dried mycelium, were found to contain squalene, sterol esters, triglycerides, free fatty acids, geranylgeraniol, free sterols, carotenoids, cardiolipin, phosphatidyl ethanolamine, phosphatidyl choline, phosphatidyl serine, and phosphatidic acid. The above compounds were isolated in pure form by column and thin layer chromatography and were characterized by infrared spectroscopy and chromatographic mobilities. Fatty acid moieties were characterized by gas liquid chromatographic retention times of their methyl esters relative to those of authentic standards. The fatty acid composition of the triglycerides was found to be similar to that of phosphatidic acid, cardiolipin, and lecithin.
Effects of changes in the major carbon source on the fatty acids ofEuglena gracilis
Authors: Reitz Ronald C. , Moore Gary S.
Published: November 2006

Euglena gracilis was cultured under both heterotrophic and phototrophic growth conditions using ethanol, glucose or CO2 as the major carbon source. Total fatty acid analyses indicated that ethanol produced more highly unsaturated acids than did glucose under both growth conditions. Growth in the light on CO2 yielded a very high content of 18∶3, 16∶3 and 16∶4 (33%), compared to ethanol (11%) or glucose (10%). These two preformed carbon sources enhanced the content of the C20 and C22 polyenes compared to CO2, and growth in the dark on to CO2, and growth in the dark on ethanol caused a further increase in these polyenes. Growth in the dark on glucose caused only a slight increase of the C20 and C22 polyenes compared to growth in the light on this carbon source. When the fatty acid patterns of the two dark‐grown heterotrophs were compared, two observations were quite evident. First, there was a two‐fold increase in the saturated acids in the cells grown on glucose. This was largely due to myristic acid. Second, the C20 and C22 polyenes were almost twice as concentrated in the cells grown on ethanol.
Inhibition of sterol biosynthesis in chlorella ellipsoidea by AY‐99441
Authors: Dickson Leal G. , Patterson Glenn W.
Published: November 2006

WhenChlorella ellipsoidea was grown in the presence of 4 ppm AY‐9944, complete inhibition of Δ5‐sterol biosynthesis was achieved. However total sterol production remained unaltered. As a result a number of sterols accumulated that appear to be intermediates in sterol biosynthesis. These sterols were described and identified as (24S)‐5α‐ergost‐8(9)‐en3β‐ol, (24S)‐5α‐stigmast‐8(9)‐en‐3β‐ol, 4α‐methyl‐(24S)‐5α‐ergosta‐8, 14‐dien‐3β‐ol, 4α‐methyl‐(24S)‐5α‐stigmasta‐8, 14‐dien‐3β‐ol, 4α‐methyl‐(24S)‐5α‐ergost‐8(9)‐en‐3β‐ol and (24S)‐4α‐methyl‐5α‐stigmast‐8(9)‐en‐3β‐ol. The occurrence of these sterols inChlorella ellipsoidea is the first time they have been noted in biological material. The accumulation of these sterols in treated cultures indicates that AY‐9944 is an extremely effective inhibitor of the Δ8→Δ7 isomerase and the Δ14 reductase of these plants. The occurrence of small amounts of other sterols in treated cultures has led to a proposed pathway for thebiosynthesis of sterols inChlorella ellipsoidea.
Esterification of cholesterol and hydrolysis of cholesteryl ester in alcohol induced fatty liver of rats
Authors: Takeuchi Nozomu , Ito Masami , Yamamura Yuichi
Published: November 2006

Repeated oral administrations of ethanol to rats induced accumulation of cholesteryl ester, as well as triglyceride in the livers. The contents of free cholesterol and phospholipid in the livers were not changed significantly in the present experiment in which ethanol ingestions were repeated four times. Although in vitro esterification of cholesterol by particle fractions of the alcoholic fatty liver was not affected, hydrolysis of cholesteryl palmitate by the supernatant fraction of the liver homogenate was reduced when compared with those of the control group which was given water or isocaloric glucose. The results of in vitro esterification of cholesterol and hydrolysis of cholesteryl palmitate in the liver of the rats which were ingested with glucose were larger than those of the control rats which were given water.
In vitro desaturation of 1‐14C linoleic acid in Novikoff hepatoma
Authors: Chiappe Liliana , Mercuri Osvaldo , Detomás María Elena
Published: November 2006

The lipid fatty acid pattern of normal liver, host liver, and Novikoff hepatoma was determined by gas liquid chromatography, and Δ6‐desaturase activity for linoleic acid was measured in the microsomal fractions. The results showed that, in Novikoff hepatoma, there is a correlation between the low content of arachidonic acid and the low activity of Δ6‐desaturase, a key enzyme in the biosynthetic pathway of this acid.
Lipids of human myocardium
Authors: Fletcher Ronald F.
Published: November 2006

The major lipid classes, including some phospholipids, and their fatty acid profiles have been measured in portions of left ventricular muscle and psoas muscle obtained at autopsy. Atrial appendages and ventricular muscle removed during cardiac surgery were examined also. The proportions of the individual phospholipids were the same in all the muscles, having an excess of phosphatidyl ethanolamine and phosphatidyl serine compared with the serum. Their fatty acid profiles resembled those obtained from other locations. The triglyceride content of the myocardium was relatively constant (except in the atrial appendage) but did rise slightly with increasing obesity. The free fatty acid concentration in the myocardium was relatively high and had a variable fatty acid profile.
Cholesterol‐cerebroside interaction: The role of α‐hydroxy fatty acids
Authors: Mickel Hubert S. , Hill Penelope L.
Published: November 2006

The esterification of cholesterol by the plasma phosphatidyl choline‐cholesterol acyltransferase reaction was studied by two methods, radioisotopic and colorimetric, in the presence of cerebroside, ceramide, or methyl esters of lignoceric or α‐hydroxy lignoceric acid. The radioisotopic method measures esterification of exogenous labeled cholesterol which must be taken up into the lipoprotein‐bound pool prior to its utilization as a substrate. The colorimetric method measures esterification of endogenous lipoprotein‐bound free cholesterol since the exogenous labeled cholesterol is negligible in concentration. Cerebroside and ceramide containing α‐hydroxy fatty acids reduced the utilization of exogenous labeled cholesterol as substrate, but had no effect on lipoprotein‐bound exogenous cholesterol esterification. Cerebroside and ceramide containing no α‐hydroxy fatty acid had no effect on exogenous labeled cholesterol esterification. The methyl esters of lignoceric acid and α‐hydroxy lignoceric acid had no effect on the esterification of exogenous cholesterol in plasma. There is a decrease in esterification of exogenous labeled cholesterol with increasing concentration of α‐hydroxy fatty acid ceramide. Increasing the concentration of exogenous cholesterol tends to counteract the effect of the ceramide on cholesterol esterification. There was little effect on exogenous cholesterol esterification when the α‐hydroxy fatty acid ceramide was exposed to plasma before adding the labeled cholesterol. The findings demonstrate an interaction between free cholesterol and cerebroside or ceramide containing α‐hydroxy fatty acids, but the nature of the interaction is not elucidated.
Analysis of lipoxygenase nonvolatile reaction products of linoleic acid in aqueous cereal suspensions by urea extraction and gas chromatography
Authors: Graveland A.
Published: November 2006

Cereals contain lipoxygenase and small quantities of linoleic and linolenic acids. For studying the oxidation of these acids by lipoxygenase in aqueous cereal suspensions and especially in doughs of wheat flour, an extraction method was developed, providing a means of quantitative extraction of the acids and their oxidation products. A complete extraction can be obtained by using urea as a disclosing agent and a chloroform‐isopropanol mixture as the extraction solvent. For the detection of the acids and their oxidation products, some of which are formed in relatively small amounts, a gas chromatographic method was developed. After extraction, the products are first methylated and silylated; then, along with an internal standard, determined with the aid of gas liquid chromatography. This method permits the determination of mono‐, di‐, and trihydroxy acids, as well as of the ketodihydroxy and α and γ ketols.
Plasma cholesterol levels in suckling and weaned calves, lambs, pigs and colts
Authors: Carroll K. K. , Hamilton R. M. G. , Macleod G. K.
Published: November 2006

Plasma cholesterol levels were determined in calves, lambs, and pigs at intervals from birth until after weaning. In each case the levels were low at birth, became elevated during the suckling period, and decreased as the animals began to eat solid feed. Results with calves fed skim milk indicated that milk lipids were largely responsible for the post‐partum elevation of plasma cholesterol levels. Studies with early and late weaned pigs also indicated that the elevation of plasma cholesterol in suckling animals was related to diet rather than age. Sex and breed had no apparent effect on plasma cholesterol levels in these experiments. A limited number of observations in colts indicated that plasma cholesterol levels decreased between 2 and 7 months.
Changes in liver lipid composition of male rats fed rapeseed oil diets
Authors: Kramer J. K. G.
Published: November 2006

Studies are reported on the effect of feeding diets containing rapessed oils differing in their erucic acid content to male weanling rats for 16 weeks. Rapeseed oil high in erucic acid depressed growth. Total lipids, lipid phosphorous and cholesterol, in the livers were not significantly different between the experimental groups. The fatty acid composition of the total liver lipids, the neutral lipids, phosphatidylethanolamine and phosphatidylcholine are documented. Erucic and eicosenoic acids were found in all lipid classes at the same relative concentration; the amount being incorporated was proportional to that found in the dietary oil. The positional analysis of phosphatidylethanolamine and phosphatidylcholine are presented. Erucic acid was incorporated preferentially at position two of these phospholipids, whereas, twice the level of eicosenoic acid was found at position one, compared to that which occurred at the two position.
Conversion of sodium lithocholate‐24‐14C to other products by guinea pig brain
Authors: Mujtaba Naqvi S. H. , Nicholas H. J.
Published: November 2006

Intracerebral injection of sodium lithocholate into guinea pig showed that this steroid can be converted into other acidic products by the brain, in vivo. One of the products has been identified as 3‐keto‐5β‐cholanoic acid.
Lipid composition of the pecan weevil,Curculio caryae (Horn)
Authors: Henson R. D. , Thompson A. C. , Gueldner R. C. , Mody N. V. , Neel W. W.
Published: November 2006

The lipids of larvae, male adults, and female adults of the pecan weevil,Curculio caryae (Horn), were studied, and special attention was given the fatty acid composition. The larvae contained an unusually high amount of lipid material (40.6%), most of it concentrated in the neutral lipid fraction. Male and famale adults contained more conventional quantities, 5.8 and 8.2%, respectively. Oleic acid was the major fatty acid in the total and neutral lipids of all stages; linoleic acid was the most abundant in the phospholipid fractions.
Egg plant lipoxygenase: Isolation and partial characterization
Authors: Grossman S. , Trop M. , Avtalion R. , Pinsky A.
Published: November 2006

Egg plant lipoxygenase EC 1.13.1.13 when purified on Ecteola cellulose was resolved into two active fractions with most of the activity in the first fraction (A). This fraction when further purified on Sephadex G200‐120 had 20 times the specific activity of the crude material. It proved to be a single substance by electrophoresis and immunological technique. The pH optimum was 6.5. Its activity was specific for thecis,cis‐1,4 pentadiene structure. There was no inhibition by cyanide, azide, EDTA or fluoride. Nordihydroguaretic acid, on the other hand, exhibited strong inhibition at 3 × 10−3M concentration. The specific antibody caused 50% inhibition.
Studies of tocopherol dimers from soybean oil by reaction gas chromatography
Authors: Gutfinger Tamar , Letan A.
Published: November 2006

Reaction gas chromatography was found to be helpful in elucidating structures of tocopherol dimers. By this method γ‐ and δ‐tocopherols were determined as monomers derived from tocopherol dimers, after isolation of the latter compounds from soybean oil. It was shown that gas chromatographic determination of tocopherols, as performed by injection of total unsaponifiables from soybean oil, will give results too high; the eluted tocopherols will account for both tocopherol monomers and dimers.
Biological implications of cadmium‐phospholipid monolayers
Authors: Belmonte Albert A. , Swarbrick James , Jensen Robert G. , Gordon Dennis T.
Published: November 2006

The potential interaction of air‐borne metal pollutants with pulmonary lung surfactant may be simulated using monolayers of dipalmitoyl phosphatidyl choline (lecithin) spread on aqueous subphases containing different metal ions. Preliminary surface pressure and surface potential results indicate that cadmium interacts with dipalmitoyl phosphatidyl choline, such that the surface characteristics of the phospholipid are altered.
cis‐5‐Monoenoic fatty acids in some chenopodiaceae seed oils
Authors: Kleiman R. , Rawls M. H. , Earle F. R.
Published: November 2006

Methyl esters from seed oils of four Chenopodiaceae species are unusual in that they contain methylcis‐5‐hexadecenoate (4.6–12%) and methyl 5‐octadecenoate (1.1–1.2%). There are indications of small amounts of 18∶25,9 and 18∶35, 9, 12 along with unsaturated acids commonly found in seed oils‐oleic (14–21%), linoleic (53–57%) and linolenic (3.5–7.8%). Fatty acid composition of the oils was determined by gas chromatography, and positions of the double bonds were established by application of gas chromatography‐mass spectrometry to the methoxylated methyl esters.
Influence of medium‐chain triglycerides on lipid metabolism in the chick
Authors: Leveille Gilbert A. , Pardini Ronald S. , Tillotson Jerry Ann
Published: November 2006

The effect of corn oil, coconut oil, and medium‐chain triglyceride (MCT, a glyceride mixture consisting almost exclusively of fatty acids of 8 and 10 carbons in length) ingestion on lipid metabolism was studied in chicks. In chicks fed cholesterol‐free diets, MCT ingestion elevated plasma total lipids and cholesterol and depressed liver total lipids and cholesterol when compared to chicks receiving the corn oil diet. As a consequence of the opposite effects of MCT ingestion on plasma and liver cholesterol and total lipids, the plasma‐liver cholesterol pool was not altered. When cholesterol was included in the diets, dietary MCT depressed liver and plasma total lipids and cholesterol as compared with corn oil, consequently also lowered the plasmaliver cholesterol pool.

The in vitro cholesterol and fatty acid synthesis from acetate‐1‐14C was higher in liver slices from chicks fed MCT than in those from chicks fed corn oil. The percentage of radioactivity from acetate‐1‐14C incorporated into the carboxyl carbon of fatty acids by liver slices was not altered by MCT feeding, indicating that the increased acetate incorporation represented de novo fatty acid synthesis. The conversion of palmitate‐1‐14C to C18 acids was increased in liver of chicks fed MCT, implying that fatty acid chain elongating activity was also increased. Studies on the conversion of stearate‐2‐14C to mono‐ and di‐unsaturated C18 acids showed that hepatic fatty acid desaturation activity was enhanced by MCT feeding. Data are presented on the plasma and liver fatty acid composition of chicks fed MCT‐, corn oil‐, or coconut oil‐supplemented diets.
Quantitative analysis of free and bound fatty aldehydes: Optimum conditions for p‐nitrophenylhydrazone formation
Authors: Ferrell William J. , Radloff James F. , Jackiw Andrew B.
Published: November 2006

A method is described for the analysis of free and bound fatty aldehydes in lipid extracts. By radiolabeling techniques it was shown that the method for measuring free fatty aldehydes when used in the presence of bound fatty aldehydes measures less than 1% of the bound aldehydes. Parameters of time, temperature and optimum acid concentration are reported. A comparison has been made between the present method and other published methods of measuring p‐nitrophenylhydrazones with emphasis on recoveries and reactivities. The present method is suitable for measuring as little as 0.02 μmoles of fatty aldehyde. The method has been applied to the analysis of free and bound aldehydes present in various mouse tissues.
Plasma free fatty acid incorporation into the outer and inner myocardium of unanesthetized dogs
Authors: Steinberg Joel S. , Gold Martin
Published: November 2006

14C‐Palmitate (16∶0) and3H‐oleate (18∶1) were infused into unanesthetized dogs for 90 min. Lipid and isotopic analyses were then performed on the left ventricular outer and inner walls. Average values in μmoles per gram wet weight tissue for both outer wall trigly ceride (TG) (7.0±2.6 (S.E.)) and phospholipid (PL) (17.3±2.4) were higher then the inner wall TG (1.4±0.3) and PL (12.0±2.4). TG fatty acid distribution was similar in the outer and inner myocardium. Thus those factors regulating incorporation of various fatty acids may operate at comparable rates in both heart segments. The same observation and relationship was observed for PL, but the two classes had markedly different fatty acid spectra. The transmural gradients for these classes may be related to relatively hypoxic conditions in the inner wall. Uniform14C DPM concentrations were found in both TG and PL of the outer and inner myocardium. A similar distribution pattern was found for3H. This may indicate that an individual species of plasma free fatty acid (FFA) undergoes uniform initial incorporation into TG and PL despite the existence of transmural gradients and fatty acid distribution differences. The mean outer and inner wall TG and PL3H to14C DPM concentration ratio (range of 3.9 to 4.8) was similar to a calculated plasma3H‐18∶1 to14C‐16∶0 specific activity ratio of 4.23. This indicates that net incorporation of fatty acids into TG and PL over 90 min was proportional to their plasma FFA concentrations, rather than to endogenous tissue lipid concentrations. The lipid gradients and fatty acid spectrum differences observed may thus be caused by recycling and catabolic pathways rather than to direct control of plasma FFA entry into TG and PL.
Partial purification and conversion of the particulate‐bound diglyceride kinase ofEscherichia coli to a water soluble, detergent free state
Authors: Horvath William L. , Pieringer Ronald A.
Published: November 2006

Alkali (pH 11.5) treatment of a washed, ammonium sulfate‐precipitated residue derived from a triton‐X‐100 extract of a 30,000 Xg particulate diglyceride kinase preparation ofE. coli converts much of the enzyme to a 100,000 Xg soluble, detergent free state. This procedure improves the enzyme as an analytical tool for the structural analysis of triglycerides, and may be applicable for the solubilization of the many other glyceride‐ and phosphoglyceride‐forming enzymes which have all resisted further purification because of insoluble, particulate properties.
Comparative effects of docosa‐4,7,10,13,16‐pentaenoic acid and docosa‐4,7,10,13,16,19‐hexaenoic acid on the desaturation of linoleic acid and α‐linolenic acid
Authors: Actis Dato S. M. , Brenner R. R.
Published: November 2006

Varying concentrations of free docosa‐4,7,10,13,16‐pentaenoic acid or its CoA ester were incubated with a given variable concentration of 1‐14C‐linoleate or 1‐14C‐α‐linolenate as either the free fatty acid or the CoA ester, microsomal enzymes, and the appropriate cofactors for fatty acid desaturation. The results obtained were compared to the effects of docosa‐4,7,10,13,16,19‐hexaenoyl CoA when incubated in a similar manner in the presence of the labeled substrates. Both feedback and crossed inhibition effects were observed; these inhibition effects may play a role in the regulation of polyunsaturated fatty acid biosynthesis.
Skin lipids of the Florida indigo snake
Authors: Ahern David G. , Downing Donald T.
Published: November 2006

Cast skins of the Florida indigo snake (Drymarchon corais) yielded up to 8% chloroform: methanol‐extractable lipid, which was found to contain methyl ketones (20%), free secondary alcohols (15%), free primary alcohols (30%), free cholesterol (15%), free fatty acids (5%), and hydrocarbons (5%). The hydrocarbons appeared to be contaminants, because gas chromatography revealed a distribution characteristic of petroleum hydrocarbons. The methyl ketones were predominantly monounsaturated, with double bonds almost exclusively in the ω7 position. The structures of the secondary alcohols corresponded with the methyl ketones in regard to chain length distribution, location of the oxygen function in the 2 position, and the proportion and position of unsaturation. The primary alcohols were also predominantly straight, odd‐carbon, unsaturated compounds, with ω7 double bonds, but with chain lengths principally of 29 and 31 carbon atoms. The free fatty acids were mainly even‐carbon monounsaturated compounds of 16–20 carbon atoms with double bonds mainly in the Δ9‐position. Inspection of the lipid structures obtained from the Indigo snake suggest a biogenetic relationship whereby palmitic and palmitoleic acids are extended in chain length mainly to 32 and 34 carbonatom fatty acids. Retention or introduction of an oxygen function in the 3 position, followed by decarboxylation, could then yield structures corresponding with the methyl ketones and the related secondary alcohols. Insertion of an oxygen atom between carbons 2 and 3 of the methyl ketones, followed by loss of the two carbon atoms thereby isolated from the chain, would produce the series of odd‐carbon primary alcohols that were observed.
Removal of lipid from intact erythrocytes and ghosts by aqueous solutions and its relevance to membrane structure
Authors: Turner John D. , Rouser George
Published: November 2006

Molar values for cholesterol, total phospholipid, and individual phospholipid classes of intact erythrocytes and their membranes (ghosts) washed with various aqueous solutions are presented. The data show that lipid can be washed from erythrocyte ghosts prepared rapidly from freshly drawn blood but that lipid is not removed from intact erythrocytes under the same conditions. Thus, it appears that the polar groups of lipids of intact cells are not exposed as they are in ghosts. In the preparation of hemoglobin‐free ghosts, up to 25% cholesterol and phospholipid can be removed, while loss of ca. 50% cholesterol and phospholipid from ghosts can be achieved with aqueous solutions containing ethylenediamine tetraacetate. No significant loss of membrane protein was encountered even when almost half of the lipid had been removed from the ghosts. Phospholipid classes were removed to different extents with different wash solutions. Lipid loss from ghosts can be prevented, in part, by adding 0.5% albumin or calcium to wash solutions containing ethylenediamine tetraacetate. These findings contrast a report where insignificant lipid loss was noted in the preparation of hemoglobin‐free human erythrocyte membranes, but agree with results reported for bovine red cell ghosts.
Detritylation by silicic acid boric acid column chromatography
Authors: Buchnea Dmytro
Published: November 2006

Chromatography on silicic acid‐boric acid columns permits detritylation of ester lipids, essentially without acyl migration, and simultaneous separation of the reaction products. Described is the preparation of the column and its application for the synthesis of diacyl‐sn‐glycerols and 2‐acyl‐1,2‐propaneiols.
The emulsifying properties of egg yolk phosphatidylcholine
Authors: Horwitz C. , Krut L. , Kaminsky L. S.
Published: November 2006

The effects of lipid concentration and w/w ratios on the formation of emulsions by some combinations of phosphatidylcholine, cholesterol oleate, cholesterol and triglyceride were studied, with the following results. Phosphatidylcholine emulsified cholesterol oleate and triglyceride, the degree of dispersion and emulsion stability increasing with phosphatidylcholine concentration. Cholesterol reduced the degree of dispersion of phosphatidylcholine‐triglyceride emulsions but enhanced the emulsion stability. Triglyceride disrupted the colloidal phase of phosphatidylcholine and cholesterol in high concentrations and did so more effectively when the proportion of cholesterol to phosphatidylcholine was high.
The synthesis of prostaglandins in human platelets
Authors: Clausen J. , Srivastava K. C.
Published: November 2006

Human blood platelets were found to possess the whole biological system for synthesis of prostaglandins from C14‐labeled acetate and inherent derivatives of essential fatty acids. The incorporation of radioactive acetate into prostaglandins, polar lipids and neutral lipids was followed as function of acetate concentration and time. Of the fractions mentioned, ca. 10% of the label was found in PGEs. Among the PGEs, PGE1 and PGE2 account for 48.6 and 43.4% of the radioactive label. The results obtained were related to the theory of the inhibiting function of prostaglandins on the platelet agglutination.