bluuebunny/crossref_metadata_2025 huggingface dataset:
A soy extract catalyzes formation of 9‐oxo‐trans‐12,13‐epoxy‐trans‐10‐octadecenoic acid from 13‐hydroperoxy‐cis‐9,trans‐11‐octadecadienoic acid
Authors: Gardner H. W. , Kleiman R.
Published: November 2006

In the presence of oxygen, a crude soy extract converted 13‐hydroperoxy‐cis‐9,trans‐11‐octadecadienoic acid into numerous products, from which 9‐oxo‐trans‐12,13‐epoxy‐trans‐10‐octadecenoic acid was isolated. Additionally, the soy extract oxidized linoleic acid to the oxo‐epoxyoctadecenoic acid, presumably via a sequential reaction involving lipoxygenase oxidation of linoleic acid followed by degradation of the resultant linoleic acid hydroperoxide. However, the linoleic acid substrate yielded two isomeric linoleic acid hydroperoxides and because of this, two isomeric oxoepoxyoctadecenoic acids.
A simplified colorimetric micromethod for determination of serum cholesterol
Authors: Bhandaru Rao R. , Srinivasan Sathanur R. , Pargaonkar Padmakar S. , Berenson Gerald S.
Published: November 2006

A simple and rapid micromethod is described for quantitation of cholesterol in 5–10 μl of serum using uranyl acetate to deproteinize the serum ando‐phthalaldehyde reagent to develop color. Independent analyses of serum samples by the present method and by two reference methods, Abell‐Kendall and automated colorimetric method, indicated accuracy of the micromethod (r=0.99). Use of capillary blood specimens makes this procedure applicable for screening infants and small children.
BF3−MeOH: A single reagent for ozonolysis of monoethylenic unsaturation
Authors: Ackman R. G.
Published: November 2006

Ozonolysis of monoethylenic fatty acids in BF3−MeOH, or in MeOH with subsequent addition of BF3−MeOH, gives oxidative fission acid products as methyl esters in a nominal 100% yield and a purity ≥98% of principal acid products. The in situ esterification step requires ca. 1 hr of heating with 7 or 14% BF3, but other time requirements are much less, totalling no more than half an hour. Different liquid phases for open‐tubular gas liquid chromatography of some products are compared.
A simple method for the preparation of pure 9‐d‐hydroperoxide of linoleic acid and methyl linoleate based on the positional specificity of lipoxygenase in tomato fruit
Authors: Matthew J. A. , Chan H. W. S. , Galliard T.
Published: November 2006

Incubation of linoleic acid with crude homogenate of tomato fruit gave a high yield (69%) of linoleic acid hydroperoxides with a ratio of 9‐ to 13‐hydroperoxide isomers of 96∶4. After chromatography of the products, as free acids or methyl esters, hydroperoxides with 9‐ to 13‐isomeric ratios of >99∶1 were obtained. The major product was characterized as 9‐d‐hydroperoxy‐octadeca‐trans‐10,cis‐12‐dienoic acid. The results demonstrate the positional specificity of lipoxygenase from tomato fruit.
Incorporation of 1‐14C‐Acetate into C26 fatty acids of the marine spongeMicrociona prolifera
Authors: Morales Reginald W. , Litchfield Carter
Published: November 2006

The incorporation of 1‐14C‐acetate into the many fatty acids of the marine spongeMicrociona prolifera was investigated. Probable precursors of 26∶2Δ5,9 and 26∶3Δ5,9,19 showed high levels of radioactivity, supporting the following pathways for the biosynthesis of C26 acids:
urn:x-wiley:00244201:lipd0570:equation:lipd0570-math-0001

Degradation of the unsaturated C26 acids at their double bonds showed that the14C was concentrated near the carboxyl end of the chain. Hence, chain elongation was the major mechanism for acetate incorporation into these acids.
Effect of dietary di‐2‐ethylhexyl phthalate on oxidation of14C‐palmitoyl CoA by mitochondria from mammalian heart and liver
Authors: Bell Frank P. , Gillies Peter J.
Published: November 2006

Oxidation of [1‐14C] palmitoyl CoA by heart and liver mitochondria from rats fed dietary di‐2‐ethylhexyl phthalate (DEHP) was investigated in vitro. Oxidation of14C‐palmitoyl CoA to14CO2 increased two‐ to threefold in hepatic mitochondria from rats fed 0.1% DEHP for 2 to 3 days; this increase appeared to be a maximum response since similar data were obtained using hepatic mitochondria from rats receiving 0.5% or 1.0% DEHP in the diet. The response of hepatic mitochondria to DEHP was found to continue throughout the duration of 35‐day trials in which 1.0% DEHP was fed. In contrast to hepatic mitochondria, the oxidation of14C‐palmitoyl CoA by heart mitochondria decreased ca. 40% upon addition of 0.1% or 0.5% DEHP to the diet; this effect of DEHP on heart mitochondria was not sustained beyond ca. 8 days of DEHP feeding. Limited studies were also performed in rabbits and pigs. Oxidation of14C‐palmitoyl CoA was increased ca. twofold in hepatic mitochondria from rabbits fed 1% dietary DEHP for 12 days and in hepatic mitochondria from pigs that received 5 doses of DEHP (0.8g/kg) at 12‐hr intervals; the oxidation14C‐palmitoyl CoA by heart mitochondria from these same animals was unchanged in the rabbit but increased an average of 37% in the pig. DEHP feeding to rats was associated with increased yields of hepatic mitochondrial protein; standardized preparations of heart mitochondria were not similarly affected.
A rapid sensitive method for determining phospholipid phosphorus involving digestion with magnesium nitrate
Authors: Duck‐Chong Coral G.
Published: November 2006

A method is described for the rapid determination of phospholipid phosphorus in samples containing less than 0.5 μg phosphorus. Phospholipid phosphorus is first converted to inorganic phosphate by heating a dried lipid extract briefly over a Bunsen flame in the presence of magnesium nitrate, then dissolving the resulting residue in dilute hydrochloric acid at 95 C. The determination of the inorganic phosphate content of the sample then requires only the addition of Triton X‐100 and an acidic ammonium molybdate‐malachite green reagent. Absorbance is measured at 650 nm after 5 min at room temperature.
Desaturation of eicosa‐11,14‐dienoic acid in human testes
Authors: Albert D. H. , Rhamy R. K. , Coniglio J. G.
Published: November 2006

The metabolism of [1‐14C]eicosa‐11,14‐dienoic acid was investigated in human testes using whole tissue minces and microsomal preparations. Both types of preparations catalyzed the desaturation of the labeled diene to eicosa‐8,11,14‐trienoic as well as eicosa‐5,11,14‐trienoic acid. The reported results, therefore, indicate that human testicular tissue, as well as rat testicular tissue (reported previously), is capable of utilizing eicosa‐11,14‐dienoic acid as a precursor of arachidonic acid. Since it is known that there is no Δ8 desaturase activity in rat liver and brain, these studies support the concept that there is a tissue variation in this enzymatic pathway.
Fatty acid and sterol specificity of cholesterol esterifying enzyme in developing rat brain
Authors: Johnson Ronald C. , Shah Shantilai N.
Published: November 2006

The properties and fatty acid and sterol specificity of cholesterol‐esterifying enzyme (EC 3.1.1.13) in rat brain were studied. The enzyme utilized free fatty acid for esterification, and activity was maximal at pH 5.6. Exogenous ATP and CoA did not stimulate the incorporation of free fatty acids into sterol esters. Substrates dispersed in Tween 20 or Triton X‐100 were just as effective as the substrates dissolved in acetone solution, while dispersion in propylene glycol or sodium taurocholate was not as effective. Snake venom phospholipase A2 (EC 3.1.1.4) increased the esterification of cholesterol in the absence of added fatty acid. The fatty acid specificity data indicated that oleic and palmitic acids were the preferred fatty acids. Little or no esterification occurred in the presence of long chain fatty acids (C20–C24). Esterification of cholesterol with palmitate or stearate was not affected by the presence of oleic acid in the mixture. Thus, the nonrequirement of the brain‐esterifying enzyme for a bile acid or for an amphiphile such as an unsaturated fatty acid suggests that micellar solubilization of the substrate is not essential for activity. Although the brain enzyme catalyzed the esterification of desmosterol, cholesterol was the preferred substrate. Neither lanosterol (C29 sterols) nor Δ7‐dehydrocholesterol was esterified to any significant extent. The presence of low concentrations of desmosterol increased cholesterol esterification slightly, while there was a concentration‐dependent inhibition of demosterol esterification by cholesterol. These data on fatty acid and sterol specificity of the esterifying enzyme correlate well with the composition of sterol esters present in developing rat brain.
Serum lipids in suckling and post‐weanling iron‐deficient rats
Authors: Sherman Adria Rothman
Published: November 2006

Serum lipids were studied in iron‐deficient and control rats during suckling and after weaning at 21, 30, and 60 days of age. Diets providing 5 or 307 ppm iron were fed to dams and their offspring during gestation, lactation, and after weaning. Rats on the deficient diet throughout the experimental period developed a hyperlipidemia characterized by elevated triglycerides, cholesterol, and phospholipids which was present at 21, 30, and 60 days. Control pups weaned to the deficient diet developed anemia at 30 days of age and hypertriglyceridemia at 60 days of age. Repletion of deficient rats with iron after weaning caused a rapid decline in serum lipid levels after only 9 days on the control diet. The hyperlipidemia of iron deficiency thus appears to be reversible with iron supplementation. The time required to develop hypertriglyceridemia in iron deficiency is longer postweaning than during suckling.
End product specificity of triacylglycerol lipases from intestine, fat body, muscle and haemolymph of the American cockroach,Periplaneta americana L.
Authors: Hoffman Alan G. D. , Downer R. G. H.
Published: November 2006

The triacylglycerol‐hydrolyzing capacity of tissue homogenates has been investigated for midgut, fat body, thoracic musculature and haemolymph of the American cockroach,Periplaneta americana. The greatest lipolytic activity was demonstrated in midgut homogenates with decreasing levels of activity present in fat body, muscle and haemolymph. Comparison of the lipolytic products resulting from triacylglycerol hydrolysis indicates that midgut homogenates effect the production ofsn‐2‐monoacylglycerols and free fatty acids, whereas the other tissues that were examined favor the accumulation of diacylglycerols. Stereospecific analysis of the diacylglycerol products of triacylglycerol hydrolysis demonstrated that the lipolytic activities of midgut and muscle homogenates result in the production of a racemic mixture of thesn‐1,2‐andsn‐2,3‐enantiomers, but the fat body and haemolymph show a preference for the accumulation of thesn‐1,2‐isomer.
On the membrane phospholipids and their acyl group profiles of adrenal gland
Authors: Sun Grace Y.
Published: November 2006

The phospholipid composition and their acyl group profiles from subcellular fractions of guinea pig adrenal gland and the same fractions from the cortex and medulla of the bovine gland were compared. The phospholipids of guinea pig adrenal were enriched in diacyl‐glycerophosphocholines (GPC) which comprised over 50% of the total phospholipids, but the proportions of ethanolamine and choline plasmalogens, sphingomyelin and diacyl‐glycerophosphoserine (GPS) were lower in guinea pig adrenals as compared to the bovine adrenals. In the bovine adrenal, sphingomyelin and diacyl‐GPS were enriched in the medulla, whereas diacyl‐glycerophosphoinositol (GPI) were enriched in the cortex. Although lysolecithin was present (up to 4.5%) in the bovine adrenal, only trace amounts of this lipid were detected in the guinea pig adrenal. Characteristic acyl group profiles were found associated with each type of the phosphoglycerides in adrenal membranes. However, acyl group profiles of the phosphoglycerides were not greatly different either between the bovine and guinea pig adrenal or with respect to the type of subcellular membranes isolated. Diacyl‐GPC were enriched in 16∶0 and 18∶1, but also contained considerable amounts of 18∶0, 18∶2 and 20∶4. Diacyl‐GPE were enriched in 18∶0, 18∶1 and 20∶4, while diacyl‐GPI, diacyl‐GPS, as well as alkenylacyl‐GPE, were enriched in 20∶4. The lysolecithin from bovine adrenal membranes contained mainly 16∶0, 18∶0 and 18∶1 with only trace amounts of the polyunsaturated fatty acids. Other polyunsaturated fatty acids, such as 22∶4 and 22∶6, are apparently not prominent in the phosphoglycerides from either the bovine or the guinea pig adrenal gland.
Comparison of lipid composition ofCandida guilliermondii grown on glucose, ethanol and methanol as the sole carbon source
Authors: Jigami Y. , Suzuki O. , Nakasato S.
Published: November 2006

The carbon and energy source for aerobically grown cultures ofCandida guilliermondii profoundly influenced the neutral lipid content and the fatty acid composition of the individual lipid components. Methanol (0.80%, w/v) grown cells cultivated at 30 C in presence of 0.025% ammonium sulfate contained 12% total lipids, 67% of which was neutral lipids. Glucose (0.74%, w/v) or ethanol (0.53%, w/v) grown cells contained 21–22% total lipids, 80% of which was neutral lipids, under the same conditions. Methanol‐grown cells contained a decreased 18∶1 acid (52–54% of total fatty acids) and an increased 18∶2 acid (23–25%), as compared with glucose‐ or ethanol‐grown cells which contained 57–66% 18∶1 acid and 8–14% 18∶2 acid, in both neutral and polar lipid fractions. The relationship between methanol metabolism and desaturation of fatty acid in yeast was discussed.
Fatty alcohols in capelin, herring and mackerel oils and muscle lipids: I. Fatty alcohol details linking dietary copepod fat with certain fish depot fats
Authors: Ratnayake W. N. , Ackman R. G.
Published: November 2006

It is shown that the shorter chain (C14‐C18) minor fatty alcohols in copepods, fish body lipids, and commercial fish oils are all qualitatively present, and quantitatively similar in proportions to acids found in the depot fats of capelin and mackerel, and in some herring. Although these fatty acids can be formed de novo in fish, copepod alcohols offer an alternative dietary source. Monoethylenic fatty alcohol details, especially for the 22∶1 isomers, are reviewed, and the latter are discussed as precursors of the 22∶1 fatty acids of fish depot fats, specifically of the dominant 22∶1ω 11 isomer.
Incorporation of deuterium‐labeledcis‐ andtrans‐9‐octadecenoic acids in humans: Plasma, erythrocyte, and platelet phospholipids
Authors: Emken E. A. , Rohwedder W. K. , Dutton H. J. , Dejarlais W. J. , Adlof R. O. , Mackin J. F. , Dougherty R. M. , Iacono J. M.
Published: November 2006

The objective of this study was to follow the uptake and distribution of oleic and elaidic acids into human erythrocytes, platelets, and plasma phospholipids. The use of dual and triple labeling methodology permitted a precise comparison of elaidic and oleic acid utilization. Elaidic acid (EI) was selectively concentrated in all the plasma phospholipids except for lysophosphatidylcholine. Three times more elaidic than oleic acid (Ol) accumulated in the 1‐acyl position of phosphatidylcholine, as determined by hydrolysis with phospholipase A2. Rapid incorporation and removal of elaidate were observed for all samples. These results support the concept that enzymes responsible for acylation of phospholipids are sensitive to double bond configuration and the physical properties of the fatty acid moieties. Labeled fatty acid levels in red cell and platelet phospholipids were much lower than for plasma phospholipids, indicating a relatively slow rate for the in vivo incorporation of fatty acids into blood cell membrane phospholipids. No isotope effect was found when oleic acid labeled with deuterium on the double bond was used.
Autoxidation of methyl esters of cyclopentenyl fatty acids
Authors: Abdel‐Moety E. M. , Lundberg W. O.
Published: November 2006

The early stages of the autoxidation of methyl hydnocarpate, chaulmoograte and gorlate in air have been examined at 40, 60 and 80 C, and the initial products have been compared by several methods with those derived from methyl oleate and linoleate autoxidized at 60 C. To supplement information about oxygen absorption and peroxide development in relation to time, other information about the early products, and some information about the reduced products, have been obtained by ultraviolet (UV) and infrared (IR) spectrophotometry, and by thin layer chromatography (TLC). The kinetic and other data presented in this study strongly support the conclusion that the methyl esters of cyclopentenyl fatty acids yield initial autoxidation products that, although they are primarily peroxides, differ in some ways (as expected) in the kinetics of their formation and their chemical nature, compared to those of oleate and linoleate. Nevertheless, all the data obtained strongly support the surmise that the peroxides are formed autocatalytically by a chain mechanism, and that secondary products not derived from peroxide decomposition, are formed pari passu in lesser, but increasing amounts with increasing temperature, probably from free radical intermediates. The autoxidation of esters of cyclopentenyl fatty acids has potential importance in several ways, 3 of which are mentioned briefly.
Biosynthesis of unsaturated fatty acids in the diatomPhaeodactylum tricornutum
Authors: Moreno Victor J. , de Moreno Julia E. A. , Brenner Rodolfo R.
Published: November 2006

The biosynthesis of fatty acids in the diatomPhaeodactylum tricornutum was studied. The diatom was incubated with sodium [114C] acetate and the acids [1‐14C] palmitic, [1‐14C] stearic, [1‐14C] linoleic and [1‐14C] α‐linolenic. The distribution of radioactivity in the products was determined by gas liquid radiochromatography. The diatom synthesized “de novo” not only saturated and monounsaturated fatty acids, but also linoleic, α‐linolenic and other fatty acids including the highly polyunsaturated 20∶5ω3 and 22∶6ω3. When labeled acetate, stearic, α‐linolenic or even linoleic acid were incubated with the diatom, the polyunsaturated C20 fatty acids synthesized belonged predominantly to the ω 3 family. The existence of Δ9, Δ6, Δ5, Δ4, ω6 and possibly ω3 desaturases inP. tricornutum is suggested.
Effect of marine oil and rapessee oil on composition of fatty acids in lipoprotein triacylglycerols from rat blood plasma and liver perfusate
Authors: Thomassen M. S. , Strøm E. , Christiansen E. N. , Norum K. R.
Published: November 2006

The fatty acid patterns of triacylglycerols (TG) from very low density lipoprotein (VLDL) in blood plasma and liver‐perfusate from rats fed partially hydrogenated marine oil or rapeseed oil were determined. In the plasma from rats fed rapeseed oil for three days and three weeks, there was a small but significant decrease in the percentage of 22∶1 fatty acid from 17.2 to 11.2% with length of feeding. In liver‐perfusate, the comparable decrease with dietary rapeseed oil was from 18.5 to 5.2%, and with dietary marine oil from 13.4 to 8.0%. In contrast to the liver‐perfusate, the remaining liver had only a very low 22∶1 composition (ca 2%) independent of feeding period or diet. The results indicated that the liver exported the very long chain fatty acids and that an adaptation took place after three days feeding with rapeseed oil or marine oil. This adaptation in the liver could possibly explain why TG accumulation in hearts, which appears after three days' feeding with rapeseed oil or marine oil, disappears after an extended feeding period.
HDL‐cholesterol levels in the multiple risk factor intervention trial (MRFIT) by the MRFIT Research Group
Authors: Hulley Stephen , Ashman Patricia , Kuller Lewis , Lasser Norman , Sherwin Roger
Published: November 2006

Preliminary data from the Multiple Risk Factor Intervention Trial (MRFIT) have been examined for evidence that the program has an influence on plasma HDL‐cholesterol. The overall mean level of this lipoprotein in the initial cohort of 1,084 men was not altered by two years of participation in this risk factor reduction project. However, changes did occur, both upwards and downwards, in some individuals. There were significant negative associations between change in HDL‐cholesterol and changes in body mass, VLDL‐cholesterol, LDL‐cholesterol, and serum thiocyanate (a measure of cigarette smoking exposure); and there was a small positive association with change in reported alcohol intake. Multiple regression analysis revealed each of these associations to be independent of the others. The fat‐controlled diet designed to lower total serum cholesterol did not decrease HDL‐cholesterol levels. We conclude that conventional risk reduction programs are not likely to lower circulating HDL‐cholesterol, and that program components such as weight reduction and smoking cessation may increase the levels.
Analysis of 4‐methyloctanoic acid and other medium chain‐length fatty acid constituents of ovine tissue lipids
Authors: Johnson C. B. , Wong E. , Birch E. J. , Purchas R. W.
Published: November 2006

Medium chain‐length (C6−C9) fatty acids in depot, intramuscular, kidney, and liver lipids from pasture‐fed sheep and subcutaneous and intramuscular lipids from barley‐fed sheep were analyzed with emphasis on the 4‐methyloctanoic acid (hircinoic acid) content. Within individual animals, the level of hircinoic acid in the subcutaneous fat was usually higher than that either in the deeper depot fats or in the intramuscular fat. Variation of hircinoic acid levels between animals was greatest in the subcutaneous fat and least in the perinephric fat. There were usually higher levels of both branched and odd carbon chain fatty acids in the lipids of barley‐fed sheep than in the corresponding lipids of pasture‐fed sheep.
Absorption of synthetic, stereochemically defined acylglycerols in the rat
Authors: Åkesson B. , Gronowitz S. , Herslof B. , Ohlson R.
Published: November 2006

The stereochemistry of fat digestion and absorption was investigated in rats with thoracic duct fistulas, after feeding synthetic triacylglycerol or alkyldiacylglycerol. After feeding 1,2‐dilauroyl‐3‐oleoyl‐sn‐glycerol, dilauroyloleoylglycerol and lauroyldioleoylglycerol were the most abundant chyle triacylglycerols. Positional analysis of the fatty acid distribution and the absence of optical activity indicated that the following structures dominated:rac‐1,2‐dilauroyl‐3‐oleoylglycerol andrac‐1,3‐dioleoyl‐2‐lauroylglycerol. Therefore, the triacylglycerol resynthesized from 2‐lauroylglycerol (precursor to 60% of chyle triacylglycerol) and other precursors was essentially racemic. Chyle phospholipids contained largely endogenous fatty acids, and the proportion of lauric acid was very low. A racemic mixture of 1,2‐di[3H] oleoyl‐3‐tetradecyl‐sn‐glycerol and 1‐tetradecyl‐2,3‐di[14C] oleoyl‐sn‐glycerol was absorbed to a lower degree than triacylglycerol. The appearance of oleic acid with different labels in chyle and intestinal lipids did not differ, indicating the absence of stereospecificity in fat digestion. Possible explanations for the low absorption are discussed.
Fiber, hypercholesteremia, and atherosclerosis
Authors: Kritchevsky David , Story Jon A.
Published: November 2006

Epidemiological data suggest that populations subsisting on high fiber diets are free of a number of the diseases of Western civilization, among them coronary heart disease. Studies in animals and man show that each type of fiber exerts it own specific influence. Thus, in man bran has no effect on serum lipids, but pectin lowers cholesterol levels. In animals fed atherogenic diets, alfalfa and pectin exert some measure of protection, but cellulose does not. To fully understand the mode of action of dietary fiber, it is necessary to ascertain the mechanism(s) of action of each chemical component of that fiber.
Fatty acid metabolism in L1210 murine leukemia cells: Differences in modification of fatty acids incorporated into various lipids
Authors: Burns C. Patrick , Wei Shiao‐Ping L. , Spector Arthur A.
Published: November 2006

L1210 leukemia cells can utilize all of the main fatty acids that normally are present in the ascites fluid in which they grow. This finding is consistent with the view that L1210 cells derive most of their fatty acids from the ascites fluid. From 80–90% of each fatty acid was incorporated into cell lipids without structural modification, suggesting that the lipid composition of these cells can be altered by changing the type of fatty acids to which they are exposed. Most importantly, the palmitate that was subsequently incorporated into total cell phospholipids was elongated and desaturated somewhat more than that incorporated into triglycerides. This difference was due primarily to more extensive modification of the palmitate incorporated into the ethanolamine phosphoglycerides fraction. Although there was no difference between total phospholipids and triglycerides with linoleate, more of the linoleate incorporated into ethanolamine phosphoglycerides was elongated and further desaturated than that incorporated into choline phosphoglycerides and triglycerides. These findings indicate that fatty acids incorporated into various cell lipid fractions are not structurally modified to the same extent. There appears to be greater modification of fatty acid used for ethanolamine phosphoglyceride synthesis as compared with triglyceride and choline phosphoglyceride synthesis.
Hepatic cholesterol synthesis from mevalonate and squalene in rats: Effect of feeding cholesterol supplemented diet during weaning and following starvation
Authors: Johnson Ronald C. , Shah Shantilal N.
Published: November 2006

The conversion of squalene to digitonin precipitable sterols by microsomes and soluble fractions from liver and the incorporation of mevalonate into nonsaponifiable lipids and digitonin precipitable sterols by 5000 g liver supernatant was studied in suckling rats and rats weaned on diet (Purina chow) supplemented with varying levels of cholesterol. The results indicate that the conversion of squalene to digitonin precipitable sterols was low in suckling rats and high in rats weaned on Purina chow diet. Weaning rats on 1% cholesterol supplemented diet effectively eliminated the post‐weaning increase in mevalonate incorporation into nonsaponifiable and digitonin precipitable sterols, and in the conversion of squalene to digitonin precipitable sterols. The incorporation of mevalonate into nonsaponifiable lipids and digitonin precipitable sterols, and of squalene into digitonin precipitable sterols also was studied in liver preparations from adult rats which were starved and refed control or cholesterol supplemented diet. It was observed that the conversion of squalene to digitonin precipitable sterols by liver fractions from fasted rats was low, while that by liver fractions from rats refed control diet was higher. Furthermore, the post‐fasting increase in the conversion of mevalonate to nonsaponifiable lipids and digitonin precipitable sterols and in squalene to digitonin precipitable sterols conversion essentially was eliminated by refeeding a 1% cholesterol supplemented diet. The low conversion of squalene to digitonin precipitable sterols in suckling rats, rats weaned on cholesterol supplemented diet, and adult rats that were starved, or starved and refed cholesterol supplemented diet, was due to the reduced activity of microsomal enzymes. It is concluded from this study that dietary cholesterol prevents the increase in cholesterol synthesis observed in developing and regenerating liver by suppressing the activities of one or more enzymes between mevalonate and squalene and between squalene and cholesterol.
Effect of light intensity upon lipid composition ofNitzschia closterium (Cylindrotheca fusiformis)
Authors: Orcutt David M. , Patterson Glenn W.
Published: November 2006

Total fatty acid, total sterol, fatty acids of specific lipid classes, and unsaturated fatty acids produced inNitzschia closterium were compared qualitatively and quantitatively as a function of changes in light intensity. Increased levels of total fatty acids were observed in cells grown at high light intensity when compared to cells grown at low light intensity. However, the percentage of unsaturated fatty acid decreased under high light conditions. Fatty acid analysis of triglyceride and 1,3 diglyceride fractions indicated an increase in levels of fatty acid at high light intensity when compared to low light intensity, while levels of polar lipid fatty acids increased at low light intensity. These analyses can be taken to indicate an increase in triglyceride and diglyceride at high light and a decrease in polar lipid at high light. Levels of free fatty acids did not differ significantly with light intensity. The levels of total sterol also were unaffected by changes in light intensity. However, levels of sterol isolated as free sterol and sterol associated in a yet unknown manner in the polar lipid fraction varied with changes in light intensity. Levels of polar lipid sterol increased at high light intensity compared to low light intensity, while the opposite was true for free sterol. The greatest percentage of total sterol was found in the polar lipid class regardless of light intensity.
Sphingophospholipids of species ofAedes andCulex mosquito cells cultivated in suspension culture from logarithmic and stationary phases of growth
Authors: Yang T. K. , Mc Means E. , Anderson L. E. , Jenkin H. M.
Published: November 2006

Two sphingophospholipids, sphingomyelin (ceramide phosphorylcholine), and ceramide phosphorylethanolamine, were isolated and purified from cells of four mosquito species obtained from the logarithmic and stationary phases of growth. Quantitation of the two lipids in both phases of growth from cells of each species was made. The fatty acid composition of the two lipids was compared between the cell types and the two phases of growth. There was a tendency for an increase of ceramide phosphorylcholine and a decrease of ceramide phosphorylethanolamine in the stationary phase. Longer chain fatty acids of ceramide phosphorylcholine were observed in the stationary phase than in the logarithmic phase of growth of the mosquito cells. The four species had distinctly different fatty acid patterns in the two complex lipids which might be useful for taxonomic purposes and cell identification.
Essential fatty acids in maternal diet and in rat milk phospholipids
Authors: Galli C. , Spagnuolo C.
Published: November 2006

The administrations of semisynthetic diets supplemented with oils and fats containing different levels of linoleic acids to lactating rats result in corresponding changes in the polyunsaturated fatty acids of triglycerides in the collected milk. Milk phospholipids show a quite different trend, polyunsaturated acids of the linoleic acid family being highest with low dietary linoleic acid supply, and vice versa, suggesting a control in the secretion of polyunsaturated fatty acids in milk.
Myocardial alterations resulting from feeding partially hydrogenated marine oils and peanut oil to rats
Authors: Ackman R. G.
Published: November 2006

Myocardial alterations were observed in 5 groups of rats fed diets containing 20% fat for 16 weeks. The incidence was comparable to that from other studies and uniform at 6/20 in hearts from rats fed: partially hydrogenated herring oil to give dietary levels of either 16.7% or 4.6% 22∶1; partially hydrogenated redfish/flatfish oil to give 4.5% 22∶1 in the dietary fat; and peanut oil (of unknown origin) containing 0.1% 22∶1. The incidence was 9/20 in the hearts of rats fed an unrefined and unprocessed redfish oil at a dietary level of 16.0% 22∶1 in fatty acids.
Plasma, apolipoprotein A‐I and A‐II levels in hyperlipidemia
Authors: Schonfeld Gustav , Bailey Alberta , Steelman Robert
Published: November 2006

Some of the component moieties of high denisty lipoproteins (HDL) were analyzed in normal subjects and in patients with hyperlipidemia. Apoproteins A‐I and A‐II were quantified by radioimmunoassay, HDL cholesterol and triglycerides were assessed on heparin‐MnCl2 supernates of fasting plasmas. We found that HDL is enriched in triglycerides in all forms of hyperlipidemia, while the proportion of ApoA‐II is unaltered and the proportion of ApoA‐I is decreased. Thus, the composition of HDL is altered in hypertriglyceridemia. The molecular associations of ApoA‐I and ApoA‐II in plasma were also examined by assaying the apoprotein contents of plasma fractions prepared by ultracentrifugation and by gel filtration column chromatography. The ApoA‐I contents of d<1.063 fraction increased in hyperlipidemia from <0.5% to ∼2%, but the ApoA‐I contents of the d>1.21 fraction remained at <12% of total in plasmas with triglyceride levels <1500 mg/dl. d>1.21 ApoA‐I rose to 23% in one plasma with a triglyceride level of >1700 mg/dl. On column chromatography, ApoA‐I eluted with the lipoproteins and also in a fraction whose molecular weight (MW) appreared to be ∼50,000 daltons. The proportion of plasma ApoA‐I which eluted in the 50,000 MW peak was positively correlated with plasma triglyceride levels, but at triglyceride levels of <1500 mg/dl, <20% of ApoA‐I was in the 50,000 MW peak. Between levels of ∼2000 and 12,000 mg/dl, the percentage “50,000 M.W. ApoA‐I” was 20–25%. The ApoA‐II contents of d<1.063 fractions were also increased in hyperlipidemia, but >95% of ApoA‐II was found in the HDL fractions in both normal and hyperlipidemic plasma both by column chromatography and ultracentrifugation. Thus, the molecular association of ApoA‐I appears to be altered in hyperlipidemia.
Bile acids in tissues: Binding of lithocholic acid to protein
Authors: Nair P. P. , Solomon Robert , Bankoski Joyce , Plapinger Robert
Published: November 2006

Human liver contains two forms of lithocholic acid. One form is readily extractable by 95% ethanol/0.1% ammonia (soluble lithocholate, SL), while the other remains firmly bound to the residue (tissue‐bound lithocholate, TBL). TBL could be hydrolytically released using clostridial cholanoylamino acid hydrolase, suggesting a peptide link between lithocholate and protein. With bovine serum albumin (BSA), lithocholic acid showed spontaneous amino group‐modifying activity. When small molecular weight lysine (α‐t‐BOC‐1‐lysyl‐β‐naphthylamide) and arginine peptides (α‐CBZ‐di‐arginyl‐β‐naphthylamide) were used in place of BSA, lithocholate bound specifically to the lysine peptide. The unusual affinity for lysine suggested that this amino acid might be involved as a residue in TBL. Synthesis of lithocholyl lysines and comparison with products of acid hydrolysis of TBL established ε‐lithocholyl lysine as the predominant form in which lithocholic acid is found in tissue bound form.
Fatty acid positional specificity in phospholipids of L1210 leukemia and normal mouse lymphocytes
Authors: Burns C. Patrick , Wei Shiao‐Ping L. , Luttenegger Diana G. , Spence Arthur A.
Published: November 2006

The positional distribution of fatty acids in the choline and ethanolamine phosphoglycerides of the L1210 murine leukemia cells was determined and compared to that of normal mouse lymphocytes. The major phospholipids of both cell types had appreciable degrees of positional specificity as evident from the higher percentage of saturated fatty acids in position 1 and of polyunsaturated fatty acids in position 2. The L1210 cells had less arachidonate and more linoleate in position 2 of choline and ethanolamine phosphoglycerides as compared to the normal lymphocytes. However, there were similar proportions of saturated, monoenoic and polyenoic fatty acids in positions 1 and 2 of the phospholipids of the L1210 leukemia cells and the lymphocytes. These data demonstrate that fatty acid positional specificity is retained in the major phospholipids of this rapidly growing tumor.
Separation of triglycerides by chain length and degree of unsaturation on silica HPLC columns
Authors: Plattner R. D. , Payne‐Wahl Kathleen
Published: November 2006

Triacylglycerols can be separated by both chain length and number of double bonds using micro particulate silica high pressure liquid chromatography columns with isooctane, diethyl ether, and acetic acid solvent mixtures. The separations obtained are the reverse of those observed with μ‐Bondapak C18 columns (Waters Associates); i.e., longer chain length triglycerides elute from the column earlier than their shorter chain homologs, and saturated triglycerides elute before the more unsaturated ones. Base line separation was obtained between tristearin, triolein, trilinolein, and trilinolenin.
Membrane‐bound phospholipid desaturases
Authors: Pugh E. L. , Kates M.
Published: November 2006

This review covers studies on membrane‐bound phospholipid desaturases in yeast and rat liver carried out in this laboratory. In yeast the desaturase system was shown to effect the direct desaturation of dioleoyl‐lecithin to dilinoleoyl‐lecithin. In rat liver the desaturase was capable of converting 2‐eicosatrienoyl‐lecithin to 2‐arachidonoyl‐lecithin. Both systems required reduced pyridine nucleotides, O2 and cytochrome b5. Eicosatrienoyl‐lecithin desaturase along with eicosatrienoyl‐CoA desaturase of rat liver microsomes was solubilized with detergents and purified 7–8‐fold from the microsomal pellets. Both activities were reconstituted in the presence of deoxycholate on addition of the other components of the cytochrome b5‐electron transport chain (cytochrome b5 and NADH‐cytochrome b5 reductase) to the solubilized desaturase; addition of lecithin further stimulated the activities. The demonstration of desaturation of eicosatrienoyl‐lecithin by a solubilized and partially purified desaturase provides strong evidence for the direct desaturation of the lecithin substrate without prior conversion to the acyl‐CoA thiolester.
The relationship of dietary fats to prostaglandin biosynthesis
Authors: Mathias Melvin M. , Dupont Jacqueline
Published: November 2006

The direct and indirect evidence that the fatty acid composition of dietary fat is involved in the regulation of prostaglandin biosynthesis was reviewed. Direct evidence included effects of essential fatty acid deficiencies and excesses on endogenous tissue levels and production rates of prostaglandins by several tissues. Indirect evidence included lipolytic, platelet aggregatory, hypertensive, inflammatory and immune responses. In general, composition of dietary fat did not affect prostaglandin biosynthesis unless a biochemical essential fatty acid deficiency was induced or the linoleate to saturated fatty acids ratio of the dietary fat was greater than 5. Most results were interpreted in light of changing fatty acid composition; however, very few direct measurements have been made.
Experimental nephrotic syndrome induced in the rat by puromycin aminonucleoside: Hepatic synthesis of neutral lipids and phospholipids from3H‐water and3H‐palmitate
Authors: Gherardi E. , Calandra S.
Published: November 2006

Experimental nephrotic syndrome (ascites, proteinuria, hypoalbuminemia, and hyperlipidemia) was induced in male Wistar rats by seven daily subcutaneous injections of puromycin aminonucleoside (20 mg/kg). Hepatic lipogenesis from3H‐water and3H‐palmitate was investigated in nephrotic and pair fed control rats by using liver slices. Total incorporation of3H‐water into neutral lipids was higher in nephrotic than in control rats (413±124 vs. 229±46 nmoles/g/hr, p<.01). Among neutral lipids, the major increase was observed for triacylglycerols (106±26 vs. 72±21 nmoles/g/hr, p<.05), cholesteryl esters (3.7±2.1 vs. 1.4±.7 nmoles/g/hr, p<.05) and, above all, for cholesterol (123 ±48 vs. 36±18 nmoles/g/hr, p<.0025). Total incorporation of3H‐water into phospholipids as well as incorporation of3H‐water into individual phospholipids were not significantly increased. Incorporation of3H‐palmitate into neutral lipids was increased (312±84 vs. 221±28 nmoles/g/hr, p<.05). Among neutral lipids, a significant increase was observed for 1,3‐diacylglycerols (19±3 vs. 13±3 nmoles/g/hr, p<.025), triacylglycerols (228±50 vs. 163±14 nmoles/g/hr, p<.05) and cholesteryl esters (18±5 vs. 10±1 nmoles/g/hr, p<.01). Incorporation of3H‐palmitate into phospholipids was not significantly affected. The difference in hepatic lipogenesis between nephrotic and control rats was even more pronounced if the data were corrected for the total liver weight which was significantly increased in the nephrotic rats (11.3±.3 vs. 8.5±.1 g, p<.001). These findings indicate that the synthesis of neutral lipids from both3H‐water and3H‐palmitate is elevated in rat with aminonucleoside‐induced nephrotic syndrome. The possible role of the increased hepatic lipogenesis in the pathogenesis of the nephortic hyperlipidemia is discussed.
Abnormal metabolism of polyunsaturated fatty acids and phospholipids in diabetic glomeruli
Authors: Kanzaki Tetsuto , Ishikawa Yo , Morisaki Nobuhiro , Shirai Kohji , Saito Yasushi , Yoshida Sho
Published: November 2006

Studies were done on changes in phospholipid content and fatty acid composition of phospholipids and on the role of the acylation pathway in synthesis of phospholipids in the development of abnormal fatty acid composition in the glomeruli of rats 2 and 10 mo after induction of diabetes with streptozotocin. The proportions of individual phospholipids in the glomeruli of rats were not changed 2 mo after induction of diabetes, but the proportion of phosphatidylethanolamine (PE) decreased and that of sphingomyelin increased 10 mo after induction of diabetes. In contrast, in liver the proportion of PE was increased and that of phosphatidylcholine was decreased. These results showed that changes of individual phospholipids in glomeruli were time‐dependent and tissue‐specific. Two mo after induction of diabetes, the main change in the phospholipid fatty acid composition of diabetic glomeruli was a decrease in arachidonic acid (AA); the main change in serum free fatty acids (FFA) was an increase in linoleic acid (LA) and a decrease in AA. Ten mo after induction of diabetes, the main changes in the phospholipid fatty acid composition of glomeruli were an increase in LA and a decrease in AA; the main change of the serum FFA composition was a decrease in AA. Thus, the fatty acid composition of glomerular phospholipids was not directly correlated to that of the serum in diabetic rats. Acyl‐CoA synthetase and acyltransferase activities increased in diabetic glomeruli with either AA or LA as substrate, but activity toward LA increased more at 2 mo after induction of diabetes. Acyl‐CoA synthetase activity increased in diabetic glomeruli with LA as substrate, but that did not change with AA as substrate at 10 mo after induction of diabetes. Furthermore, acyltransferase activity decreased in diabetic glomeruli with AA as substrate, although that did not change with LA as substrate at 10 mo after induction of diabetes.
Isoprenoid fatty acids from marine sponges. Are sponges selective?
Authors: Carballeira Nestor M. , Maldonado Lilliam , Porras Beatriz
Published: November 2006

The burrowing spongesAnthosigmella varians andSpheciospongia vesparium were found to be rich in the isoprenoid phospholipid fatty acid 4,8,12‐trimethyltridecanoic (5.2% and 23%, respectively, of the total fatty acid composition), while the burrowing spongeChondrilla nucula and the demospongeAgelas dispar contained the acid 3,7,11,15‐tetramethylhexadecanoic (13.8% and 8.6%, respectively, of the total phospholipid fatty acid composition). No other isoprenoid fatty acid was found, and the two acids described in this work did not occur concomitantly in the same sponge.
Phospholipid studies of marine organisms: 14. Ether lipids of the spongeTethya aurantia
Authors: Smith Glenn M. , Djerassi Carl
Published: November 2006

The novel unesterified alkyl glycerol monoethers, (2S)‐1‐(hexadecyloxy)‐2,3‐propanediol (1), (2S)‐1‐(16‐methylheptadecyloxy)‐2,3‐propanediol (2) and (2S)‐1‐(15‐methylheptadecyloxy)‐2,3‐propanediol (3) were isolated from the marine spongeTethya aurantia and were characterized by spectroscopic methods. These three saturated ethers as well as a series of alk‐1′‐enyl glycerol monoethers were also encountered in the phospholipids of the same sponge after reduction with LiAlH4. Incorporation experiments with dissociated cells ofT. aurantia indicated that [1‐14C]‐hexadecanol was incorporated into the unesterified alkyl glycerol monoethers.
Liver parenchymal cells differ from the fat‐storing cells in their lipid composition
Authors: Hendriks Henk F. J. , Brekelmans Pieter J. A. M. , Buytenhek Rien , Brouwer Adriaan , Margreet de Leeuw A. , Knook Dick L.
Published: November 2006

The neutral lipid and phospholipid compositions of purified sinusoidal (fat‐storing, endothelial and Kupffer) cells, parenchymal cells and liver homogenates were determined by thin layer chromatography. In addition, the retinoid content of the same purified cell populations was determined by high performance liquid chromatography. From each cell type, both a lipid droplet fraction and a pellet fraction (containing the majority of the remaining cell organelles) were prepared by differential centrifugation. Electron microscopic analysis showed that lipid droplets isolated from fat‐storing cells were larger (up to 8 μm) than those isolated from parenchymal cells (up to 2.5 μm). Moreover, the parenchymal lipid droplets seemed to be surrounded by a membranous structure, while the fat‐storing lipid droplets seemed not to be. Both fat‐storing and parenchymal cells contained high concentrations of neutral lipids, 57.9 μg and 71.0 μg/106 cells, respectively, while endothelial and Kupffer cells contained only 8.6 μg and 13.8 μg/106 cells of neutral lipids, respectively. Sixty‐five percent of fat‐storing cell lipid droplet fractions comprised esters of retinol and cholesterol. This combined ester fraction contained mainly retinyl esters. In addition, considerable quantities (20%) of triglycerides were present. Parenchymal cell lipid droplet fractions comprised triglycerides (62%) and cholesteryl esters (up to 30%). The pellet fractions prepared from all four cell types consisted mainly of cholesterol (41–67%) and free fatt acids (20–28%). The phospholipid content was much higher in parenchymal cells than in the sinusoidal liver cell types. The relative proportions of the four major phospholipid classes were comparable in all liver cell types analyzed. It is concluded that parenchymal cell lipid droplets comprised mainly triglycerides and cholesteryl esters, which is in agreement with the function of parenchymal cells in lipid metabolism. Fat‐storing cell lipid droplets consisted of retinyl esters and triglycerides, which correlates well with their function in retionid storage and metabolism.
Periodate‐induced lipid oxidation of erythrocyte membranes
Authors: Beppu Masatoshi , Kikugawa Kiyomi
Published: November 2006

Exposure of human erythrocyte ghosts to 0.2–5 mM periodate at 0 C for 15 min resulted in an increase of thiobarbituric acid‐reactive substances and fluorescent materials in the membranes. This increase was suppressed by radical scavengers, butylated hydroxytoluene and thiourea, indicating that periodate caused lipid oxidation of ghosts. A role of hemoglobin in the periodate‐induced lipid oxidation of ghosts was suggested by the fact that the oxidation was augmented by hemoglobin and inhibited by an iron chelator, desferrioxamine. Treatment of ghosts with periodate caused membrane protein cross‐linking with and without disulfide bridge. Erythrocytes were also susceptible to lipid oxidation by periodate, but only disulfide‐mediated protein cross‐linking was observed. Erythrocytes treated with neuraminidase or trypsin were less susceptible, but those treated with neuraminidase along with galactose oxidase were nearly as susceptible as untreated cells. The effect of galactose oxidase was diminished by reduction of the enzyme‐treated cells with borohydride. These results indicate that the aldehyde moieties generated by periodate at the sialyl residues or those generated by galactose oxidase at the terminal galactosyl orN‐acetyl galactosaminyl residues of the membrane glycoconjugates play a stimulating role in the periodate‐induced membrane lipid oxidation.