bluuebunny/crossref_metadata_2025 huggingface dataset:
Lipid composition of yoshida ascites hepatoma and of livers and blood plasma from host and normal rats
Authors: Ruggieri S. , Fallani A.
Published: November 2006

The lipid composition of Yoshida ascites hepatoma cells was analyzed together with that of ascitic plasma and of livers and blood plasma from host and normal rats. In comparison to normal livers, host livers showed no significant differences in the content of the various lipid classes, but contained a higher percentage of palmitic acid and a lower proportion of arachidonic acid in the major phospholipid classes. In addition, tumor growth induced a marked hypertriglyceridemia in host animals; changes in the concentration of other plasma lipid classes were not statistically significant. The ascitic plasma contained small amounts of lipids mainly constituted by cholesteryl esters and phospholipids. Yoshida hepatoma cells contained less phospholipids in comparison to both host and normal liver, while the increased level of triglycerides and the decrease of free fatty acids were not statistically significant. Hepatoma cells showed appreciable amounts of ether‐linked lipids associated in part to neutral lipids (as glyceryl ether diesters) and, in part, to ethanolamine and choline phosphoglycerides. The alkyl groups in GEDE as well as in ethanolamine and choline phosphoglycerides were mainly constituted by C16∶0 and C18∶0 followed by C18∶1. The alk‐1‐enyl groups in ethanolamine and choline phosphoglycerides were C16∶0 and C18∶0 with only a minor proportion of C18∶1. In comparison to both host and normal liver, Yoshida hepatoma cells showed significant changes in the fatty acid composition of neutral lipids and phospholipids. Some of the major changes consisted of an increase of monoenoic acids associated with a decrease of arachidonic and docosahexaenoic acids in phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol.
Inhibition of sterologenesis in brain and liver of fetal and suckling rats from dams fed di‐2‐ethylhexyl phthalate plasticizer
Authors: Bell Frank P. , Makowske M. , Schneider D. , Patt C. S.
Published: November 2006

The effect of di‐2‐ethylhexyl phthalate (DEHP) on lipid metabolism was studied in liver and brain from fetal rats taken 3 days before parturition from dams receiving dietary DEHP during gestation. In fetuses from rats receiving 0.5% or 1.0% DEHP in a stock diet, the incorporation of14C‐acetate and labeled mevalonate (3H or14C) into the C27 sterols, C30 sterols, and squalene fractions of brain tissue incubated in vitro was significantly reduced between the confidence limits P<0.05 to P<0.001. When liver from fetuses was incubated with labeled mevalonate, incorporation of label into the C27 sterol and C30 sterol fractions was significantly reduced as well (P<0.02 to P<0.001), whereas incorporation of labeled mevalonate into the squalene fraction was not significantly altered. The incorporation of14C‐acetate into total hepatic lipids of the fetal rats was also studied, and statistically significant reductions in incorporation were observed in the lanosterol fraction (P<0.001), the combined fraction of sterol esters + squalene (P<0.02), and the combined fraction of cholesterol + diglycerides (P<0.01). No significant changes were observed in the incorporation of14C‐acetate into phospholipids, free fatty acids, or triglycerides. In 8‐day old suckling rats delivered from dams fed 0.5% DEHP for the last 16 days of gestation and maintained on the same diet during the nursing period, the incorporation of14C‐mevalonate into hepatic C27 sterols, in vitro, was significantly depressed (P<0.05) whereas in corporation into C30 sterols and squalene was similar to control values. In these same suckling rats, body weights were significantly lower in the control group (21.7 vs. 18.8 g, P<0.01), whereas liver weight as a % of body weight was significantly higher (P<0.01) in rats nursing from the DEHP‐fed dams. The results indicate that the inhibitory effect of dietary DEHP on lipid metabolism in the mature rat is transmitted across the placental barrier to the developing fetus and that the abnormal pattern of lipid metabolism in rats delivered from DEHP‐fed females is only partially restored to normal during the suckling periods.
Linoleic acid absorption in the unaesthetized rat: Mechanism of transport and influence of luminal factors on absorption
Authors: Chow S. L. , Hollander D.
Published: November 2006

Linoleic acid intestinal absorption was studied in the unanesthetized rat. At low (21–1260 μM) intraluminal concentrations, absorption took place by facilitated diffusion; while at high (1.26–2.5 mM) concentrations, simple diffusion was the predominant mechanism of transport. At low concentrations (840 μM), the equimolar additions of oleic, linolenic, and arachidonic acids or lecithin inhibited the absorption of linoleic acid. Substitution of potassium for sodium in the buffer solution, substitution of Tween 80 for sodium taurocholate, or decrease in the hydrogen ion concentration all resulted in decreased rate of linoleic acid's absorption. These experiments demonstrate that linoleic acid is absorbed by a concentration‐dependent dual mechanism of transport. The absorption rate is modified by the pH, surfactant type and concentration, the simultaneous presence of other polyunsaturated fatty acids, and the thickness of the unstirred water layer.
Thiobarbituric acid test for detecting lipid peroxides
Authors: Asakawa T. , Matsushita S.
Published: November 2006

The thiobarbituric acid (TBA) test has been used in the field of medical science in recent years to detect lipid peroxides. In this case, it is necessary for hydroperoxides to be decomposed to secondary products during the reaction. When purified methyl linoleate and methyl linolenate monohydro‐peroxides were used as the sample for the TBA test, they did not decompose entirely to secondary products, but did so completely when an iron catalyst (ferrous sulfate) was added. However, the iron catalyst also accelerated the autoxidation of coexisting unsaturated fatty acids. Therefore, the addition of antioxidants was required. Fifteen min of heating was sufficient to complete the reaction. With additions of catalyst and antioxidant to the TBA test, it may be possible to make useful distinctions between hydroperoxides and secondary products of lipid oxidation.
A review of the unique features of HDL apoproteins
Authors: Pownall Henry J. , Morrisett Joel D. , Sparrow James T. , Smith Louis C. , Shepherd James , Jackson Richard L. , Gotto Antonio M.
Published: November 2006

The human plasma high density lipoproteins (HDL) are a heterogeneous ensemble of five proteins associated with both neutral and polar lipids. The sequences of all five proteins are known. ApoA‐I and apoA‐II are the major protein components; apoC‐I, apoC‐II and apoC‐III are the minor protein components. All these apoproteins spontaneously recombine with phospholipids to give stable lipid‐protein complexes and freely exchange between the two major HDL subclasses, HDL2 and HDL3. In addition, ApoC‐I, apoC‐II, and apoC‐III exchange between HDL and very low density lipoproteins. Furthermore, certain HDL apoproteins are activators for plasma enzymes that are important in lipid metabolism. ApoA‐I and apoC‐I activate lecithin/cholesterol acyltransferase; apoC‐II is an activator of lipoprotein lipase. The regions of apoC‐I and apoC‐II that are involved in the activation of these enzymes have been localized with synthetic peptides. Studies of synthetic and native fragments of apoA‐II, apoC‐I, apoC‐II, and apoC‐III as well as model lipid‐binding peptides have identified specific regions with structural features common to lipid‐binding proteins. These special properties, which include helical potential, sequences with a critical amphipathic length, and high hydrophobicity of the nonpolar side of the amphipathic helix, are the determinants of HDL structure and metabolism.
Phospholipid exchange between subcellular organelles of rabbit lung
Authors: Spalding J. W. , Hook G. E. R.
Published: November 2006

A soluble protein fraction (PLEP) prepared from rabbit lung can catalyze the exchange of phospholipids between subcellular organelles of the lung and between these subcellular organelles and synthetic liposomes. Phospholipid exchange between microsomes and synthetic liposomes and between mitochondria and synthetic liposomes was stimulated 8‐fold and 2.5‐fold, respectively, in the presence of the protein fraction. Lung exchange protein could also catalyze phospholipid exchange between subcellular organelles of the liver and synthetic liposomes. Phospholipid transfer between microsomes and lamellar bodies of the lung was stimulated 2‐fold by the exchange protein. Both radiolabeled phosphatidylcholine (PC) and phosphatidylinositol (PI) were transferred from32P‐labeled microsomes to lamellar bodies, but the exchange protein exhibited no transfer activity for phosphatidylglycerol (PG) and that for phosphatidylethanolamine (PE) was insignificant compared to the transfer activity for phosphatidylcholine and phosphatidylinositol. While the physiological role of the phospholipid exchange proteins in the lung is unknown, it is possible that they participate in the distribution of the newly synthesized phospholipids from the site of synthesis to lamellar bodies and other membrane compartments of cells.
The metabolic fate of cholesterol‐5α,6α‐epoxide in vivo
Authors: Bowden J. P. , Muschik G. M. , Kawalek J. C.
Published: November 2006

[14C] Cholesterol‐5α,6α‐epoxide, administered to mice by either gastric intubation or skin painting, was rapidly and primarily excreted in the feces. Residual amounts of the epoxide and its metabolites were found in a wide variety of organs, and persisted for at least 72 hr. At some sites (principally the liver, the small intestinal contents and the combined stomach/duodenum and their contents), the labeled compound existed in a water‐soluble form which could not be extracted with chloroform/methanol. Treatment of the small intestinal contents with a preparation of β‐glucuronidase/sulfatase produced a marked increase in the amount of organic‐solvent‐extractable cholesterol‐α‐epoxide and other polar metabolites. Unchanged epoxide was found mainly in the feces and the skin at the site of application. On the basis of these results, stool specimens, and not blood samples, should be analyzed to detect the presence of this compound and/or its metabolites in vivo.
Varietal differences in peanut triacylglycerol structure
Authors: Sanders T. H.
Published: November 2006

Stereospecific analysis of triacylglycerols from six peanut varieties showed diversity in percent fatty acid placement. Distribution of the fatty acids among thesn‐1,‐2 and‐3 positions was clearly nonrandom. The percentages of palmitic and stearic acids, generally very low at thesn‐2 position, were more predominant at thesn‐1 than thesn‐3 position. Long chain fatty acids were located almost exclusively at thesn‐3 position. Thesn‐2 position of all varieties was high in unsaturated fatty acids. Triacyglycerols were sufficiently different to suggest that concentrations of specific triacylglycerol species may vary with variety.
Autoxidation of fatty acid monolayers adsorbed on silica gel. IV. Effects of antioxidants
Authors: Wu Guey‐Shuang , Stein Robert A. , Mead James F.
Published: November 2006

Inclusion of α‐ or γ‐tocopherol in linoleic acid monolayers deposited on a silica gel surface introduced a definite induction period before the initiation of rapid autoxidation, as measured by the disappearance of linoleic acid. The length of the inducation period was found to be proportional to the amounts of tocopherol incorporated at the concentration range tested, and the protection was generally efficient with little loss of linoleic acid to autoxidation. At the onset of the rapid autoxidation, approximately 12% of the tocopherol remained, and most of this was destroyed after an additional short period. γ‐Tocohperol, at the same concentration, was found to be 1.4 times as effective as the α‐isomer. 3‐(ω‐Carboxynonyl)‐4‐methoxy‐5‐pentylphenol, the synthesis of which is described here, did not introduce a detectable induction period, but rather reduced the overall rate of autoxidation throughout a very long period.
Perinatal development of 3‐hydroxy‐3‐methylglutaryl coenzyme a reductase activity in rat lung, liver and brain
Authors: Ness Gene C. , Miller John P. , Moffler Mary H. , Woods Linda S. , Harris Howard B.
Published: November 2006

The developmental pattern of microsomal 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase (EC 1.1.1.34), which catalyzes the rate‐limiting step of cholesterol biosynthesis, was studied in lung, liver and brain of Sprague‐Dawley rats. Each tissue exhibited a distinet pattern. Reductase activity in the fetal lung reached a peak at 19 days of gestation, which corresponds to the onset of active surfactant production. This observation is consistent with the suggestion that the fetal lung synthesizes all surfactant components including cholesterol. In the liver, reductase activity varied in a reciprocal fashion with serum cholesterol levels. The peak of brain reductase activity occurred at 3 days after birth at the onset of rapid brain growth despite rapidly rising serum cholesterol levels.
The effect of steroids and their solubilizing agents on mycelial growth ofPhytophthora cactorum
Authors: Nes W. David , Patterson Glenn W. , Bean George A.
Published: November 2006

Mycelia ofPhytophthora cactorum, a fungus unable to synthesize sterols, were incubated with a series of sterols and several common sterol solubilizing agents. Cholesterol, campesterol, and sitosterol promoted growth, while carpesterol, saringosterol, 20 α‐hydroxy cholesterol, coprostanol, and 5α‐cholestane inhibited growth. Cholestanol, epicholestanol, and 5α‐cholestan‐3‐one had no significant effect on growth relative to the sterol‐free control. All steroids were solubilized in ethanol for studying structure‐activity correlations. The added steroids were reisolated from mycelia and their identity confirmed by gas liquid chromatography (GLC) or combined gas liquid chromatography‐mass spectrometry (GLC‐MS). Tween 80 promoted growth, Triton X‐100 inhibited growth, and ethanol had no effect on growth relative to a control.
Effects of diets high in saturated fat and cholesterol on the lipid composition of canine platelets
Authors: Pitas R. E. , Nelson G. J. , Jaffe R. M. , Mahley R. W.
Published: November 2006

The phospholipid composition of platelets from dogs on various experimental diets was determined. Thyroidectomized foxhounds were fed a control diet or the control diet supplemented with (1) beef tallow, (2) beef tallow and cholesterol, or (3) beef tallow, cholesterol, and safflower oil for 23 weeks prior to isolation of platelets. Platelets from animals fed the control diet contained 36.7% phosphatidylcholine (PC), 22.8% phosphatidylethanolamine (PE), 18.4% sphingomyelin (Sph), 11.8% phosphatidylserine (PS), 6.3% phosphatidylinositol (PI), and 2.2% lysophosphatidylcholine. The PE was 77.6% in the plasmalogen form. No highly significant changes in the phospholipid class composition resulted from the experimental diets. Cholesterol supplementation of the diets, however, caused consistent alterations in the fatty acid compositions of the platelet phospholipids including increases in the percentages of 18∶1ω9 (oleic acid), 18∶2ω6 (linoleic acid), and 20∶3ω6 (homo‐gamma linolenic acid) and a decrease in the percentage of 20∶4ω6 (arachidonic acid). Addition of safflower oil to the tallow‐cholesterol diet partially reversed these effects. These cholesterol‐induced alterations in fatty acid composition could be due to exchange with plasma lipids, de novo synthesis, or altered platelet metabolism. The mechanism remains to be determined.
Evidence for the lipoprotein heterogeneity of human plasma high density lipoproteins isolated by three different procedures
Authors: Suenram A. , McConathy W. J. , Alaupovic P.
Published: November 2006

Quantitative electroimmunoassays of apolipoproteins in ultracentrifugally isolated high density lipoproteins (HDL) of normolipidemic subjects showed that A‐I and A‐II are the major (80–85% of total HDL protein) and B, C‐III, E, D and F are the minor protein constituents of this density class. A comparison between the apolipoprotein composition of ultracentrifugally isolated HDL and heparin‐Mn++ supernates showed no significant difference in the levels of A‐I and C‐III. However, the concentration of ApoE in the heparin‐Mn++ supernates was almost twice as high as that in the ultracentrifugally isolated HDL; ApoB was only detectable in trace amounts in the heparin‐Mn++ supernates. To establish whether these apolipoproteins are parts of a single macromolecular complex or form separate, discrete lipoprotein particles, the high density lipoproteins were isolated by three different procedures including ultracentrifugation, heparin‐Mn++ precipitation and agarose column chromatography. The double diffusion analyses of each of these HDL preparations with antisera to A‐I, A‐II, ApoB, C‐III, ApoD, ApoE, and ApoF showed nonidentity reactions between each possible combination of these antisera. The only exception was a reaction of partial identity between antisera to A‐I and A‐II polypeptides indicating the occurrence of two types of lipoprotein particles, a major one (LP‐A) containing both polypeptides and a minor one (LP‐A‐I) containing A‐I as the sole protein constituent. These findings indicate that high density lipoproteins, regardless of the manner of isolation, do not consist of a single macromolecular complex, but represent a mixture of several, discrete lipoprotein families.
Behavior of gangliosides on dialysis
Authors: Ghidoni R. , Sonnino S. , Tettamanti G.
Published: November 2006

Mixed brain gangliosides or individual ganglioside GM1 were dissolved in one of the following solvents: (a) water, (b) 0.1 M aqueous KC1, or (c) methanol‐aqueous 0.1 M KC1 at concentrations ranging from 10−8 to 10−3 M, and were submitted to dialysis against distilled water for up to 4 days. No significant loss of gangliosides on dialysis was observed when gangliosides were dissolved in water or 0.1 M aqueous KC1, but a loss occurred when the ganglioside solution contained methanol; the loss was greater at the lowest ganglioside concentration. However, losses ceased to occur after 1 day when methanol was removed from the dialysis sac.
Inhibition of cholesterol synthesis in mammary tissue, lung, and kidney following cholesterol feeding in the lactating rat
Authors: Kris‐Etherton P. M. , Frantz I. D.
Published: November 2006

Pregnant rats were randomly allocated to one of 3 experimental dietary groups: Group 1–15.5% butter, 2% cholesterol, 0.78% sodium cholate purified diet; Group 2‐standard rat diet with the addition of 10% lard and 2% cholesterol, and Group 3‐standard rat diet. Plasma and milk cholesterol at 10 days postpartum were significantly elevated in dams fed exogenous cholesterol. The rat of incorporation of [1‐14C] acetate into digitonin‐precipitable sterols of mammary tissue slices from dams in Group 1 and Group 2 was eight‐fold and two‐fold, respectively, less than controls. Mammary tissue cholesterol was greater in dams fed dietary cholesterol. Thus, our data, for the first time, demonstrate that cholesterol synthesis in lactating rat mammary tissue is suppressed following cholesterol feeding. In a second experiment, the rate of incorporation of [1‐14C] acetate into digitonin‐precipitable sterols in kidney and lung tissue of Group 1 rats was suppressed; however, this response was not as marked as that observed in lactating mammary tissue. The concentration of cholesterol in kidney and lung was greater than controls. These results suggest that extrahepatic inhibition of cholesterol synthesis exists in the rat with a concomitant increase in tissue cholesterol.
Synthesis of phosphatidylcholine and phosphatidylethanolamine at different ages in the rat brain in vitro
Authors: Brunetti Marina , Gaiti Alberto , Porcellati Giuseppe
Published: November 2006

The de novo synthesis of choline and ethanolamine phosphoglycerides in brain microsomes from 18 month‐old male rats was investigated in vitro by using labeled cytidine‐5′‐diphosphate choline and cytidine‐5′‐diphosphate ethanolamine as lipid precursors. The rate of synthesis of the two phospholipid classes was found to be noticeably decreased, as compared to that of adult animals. The addition of exogenous diacyl glycerols to microsomes from ageing rat brain brings the rate of synthesis nearly to the adult levels. The synthesis of choline and ethanolamine phosphoglycerides is not affected in the liver microsomes of ageing rats. The molar distribution of fatty acids in brain microsomal diacyl glycerols of ageing rats is noticeably different from that of adult animals. The content of monoenoic and dienoic species is increased, whereas that of the tetraenoic species is decreased. Base exchange reaction for choline and ethanolamine incorporation into respective phospholipids is not affected in the brain microsomes of the aged rats.
Lipid oxidation products and chick nutritional encephalopathy
Authors: Budowski P. , Bartov I. , Dror Y. , Frankel E. N.
Published: November 2006

Safflower oil and its distilled methyl esters were thermally oxidized and fed to young chicks in a vitamin E deficient diet. At a dietary level of 10%, the oxidized lipids caused more severe nutritional encephalopathy (NE) than the unoxidized methyl esters, indicating that factors other than dietary linoleic acid and vitamin E affect the development of NE. A polar lipid extract from oxidized methyl esters accelerated the induction of NE, as did the synthetic methyl esters of keto‐octadecenoic and keto‐octadecadienoic acids. Dicumarol exerted a protective action against NE. The possibility is discussed that conjugated keto‐polyenoic fatty acids, provided by oxidized oils or formed endogenously in vitamin E deficiency, may play a role in causing NE.
Geometrical and positional isomer content of the monounsaturated fatty acids from various rat tissues
Authors: Wood Randall , Chumbler Fred , Matocha Martha , Zoeller Andrew
Published: November 2006

The percentage distribution of the geometrical and positional isomers in the hexadecenoates and octadecenoates isolated from triglycerides, phosphatidylch olines, and phosphatidylethanolamines of brain, heart, kidney, liver, lung, muscle, spleen, and adipose tissues from normal rats maintained on a laboratory diet has been determined. All of the octadecenoates and most of the hexadecenoates from the lipid classes of all the tissues consisted of more than 95%cis isomers. Generally, palmitoleic was the predominant hexadecenoate, but many of the tissue phospholipids contained relatively high percentages of the Δ6 and Δ7 isomers. Oleate and vaccenate were the predominant octadecenoates in all tissues. Except for brain and adipose tissues, the oleate to vaccenate ratios differed for each lipid class, as well as between most tissues. In contrast to the monoenes of the phospholipids, the triglyceride monoenes exhibited the same approximate: percentage composition; percentage of geometrical isomers; and percentage distribution of hexadecenoate and octadecenoate positional isomers. These data add to our basic information about the percentage distribution of geometrical and positional isomers of naturally occurring unsaturated fatty acids in the major lipid classes of various normal tissues. Some new concepts were advanced as possible explanations to some of the observed positional isomer distributions.
Prenatal protein depletion and Δ9, Δ6 and Δ5 desaturases in the rat
Authors: Mercuri Osvaldo , de Tomás María Elena , Itarte Herminia
Published: November 2006

Pregnant rats were kept throughout gestation on a control diet (i.e., 25% protein), on a low protein diet (i.e., 5% protein) or on a fat‐free diet. At 20–21 days of gestation, the rate of 9‐, 6‐, and 5‐desaturation was measured, using microsomes from maternal and fetal livers and placenta microsomes. The effect of protein malnutrition was more evident upon Δ6‐desaturase activity from maternal liver, while a less severe reduction in the activities of Δ9‐ and Δ5‐desaturases was observed. No measurable activities of Δ5‐ and Δ6‐desaturases were observed in fetal liver and placenta, while a low activity of Δ9‐desaturase was detected in both tissues from the three groups under study. We concluded that Δ6‐desaturation is greatly affected by maternal protein deprivation, and this fact could affect the normal supply of polyunsaturated fatty acids for the normal fetus growth and tissue development.
Correlations between surface area and the rate of enzymatic desaturation with methyl branched 8,11,14‐eicosatrienoic acid
Authors: Patil Gajanan S. , Sprecher Howard , Cornwell David G.
Published: November 2006

Methyl‐branched derivatives of methyl 8,11,14‐eicosatrienoate form stable liquid‐expanded monolayers. Surface areas are expanded by the methyl branch. The expansion effect is a function of surface pressure. At high surface pressure, the greatest expansion occurs with a mid‐point methyl branch. At low surface pressure, surface area increases continuously as the methyl group is moved along the carbon chain from carbon 19 to carbon 5. Desaturase activity varies inversely with surface area, and a linear correlation exists between surface area at low surface pressure and the desaturation rate. These data support the concept that lipid structure and its effect on short range forces between molecules is an important factor in desaturase activity.
Isoflavones and hypercholesterolemia in rats
Authors: Sharma R. D.
Published: November 2006

Isoflavones isolated from three commonly used pulses such as Bengalgram (Cicer arietinum), greengram (Phaseolus aureus) and blackgram (Phaseolus mungo) and p‐coumaric acid were supplemented to hypercholeste rolemia‐inducing diet of rats. Among isoflavones, Biochanin A and Formononetin showed hypolipidemic activity but diadzein did not; p‐coumaric acid also produced a significant reduction in serum cholesterol levels.
Plasma lipoprotein changes in suckling and weanling rabbits fed semipurified diets
Authors: Roberts D. C. K. , Huff M. W. , Carroll K. K.
Published: November 2006

The distribution and composition of the plasma lipoproteins were studied in suckling rabbits and in rabbits either weaned to or fed as young adults cholesterol‐free, semipurified diets containing protein of animal (casein) or plant (soy protein isolate) origin. The raised cholesterol levels of the suckling period resulted in an increase of very low density and intermediate density lipoproteins in a manner similar to that seen in adult rabbits fed a high fat diet supplemented with cholesterol. Young rabbits fed the cholesterol‐free, semipurified diet containing casein also became hypercholesterolemic but, in this case, the increased cholesterol was found primarily in lipoproteins of intermediate density. Cholesterol levels remained low in those rabbits fed the soy protein isolate diet, and the lipoprotein distribution was somewhat similar to that of chow‐fed animals. It appears that the raised cholesterol levels during the suckling period result in different lipoprotein patterns to those produced in young adult animals by a cholesterol‐free, semipurified diet.
A simplified procedure for the quantitative extraction of lipids from brain tissue
Authors: Phillips F. , Privett O. S.
Published: November 2006

A method is described for the quantitative extraction of lipid from brain tissue with chloroform/methanol (C/M) that eliminates secondary purification of the lipid extract by dextran‐gel chromatography or aqueous washing of the organic extract. Nonlipid substances that generally contaminate C/M lipid extracts are separated by pre‐extraction of the tissue with dilute (0.25%) aqueous acetic acid. The residual tissue is extracted twice with 40 volumes of C/M (1∶1, v/v). Approximately 97% of the lipid is recovered in these extractions. A third extraction which yields ca. 1% more lipid is performed if the process is discontinued at this stage in a shortened version of the method. The remainder of the lipid is recovered after treatment of the tissue with 1 N HCl by two additional extractions, the first with 40 volumes of C/M (1∶2, v/v) and the second with 40 volumes of methanol. The method, which was demonstrated with pig brain, gave a complete extraction of the lipid, including gangliosides, free of nonlipid substances.
The conversion of phosphatidylethanolamine into phosphatidylcholine labeled in the choline group using methyl lodide, 18‐crown‐6 and potassium carbonate
Authors: Patel K. M. , Morrisett J. D. , Sparrow J. T.
Published: November 2006

A chemical method for the conversion of phosphatidylethanolamine into phosphatidylcholine is described. Methyl iodide in the presence 18‐crown‐6 (1,4,7,10,13,16‐hexaoxacyclooctadecane) and potassium carbonate in benzene is used to alkylate phosphatidylethanolamine in 2.5 hr at 37 C to give an isotopically enriched phosphatidylcholine. The product is purified conventionally and is obtained in 75% yield.
Composition of the lipids in human milk: A review
Authors: Jensen R. G. , Clark R. M. , Ferris A. M.
Published: November 2006

Recent publications on the composition of human milk are reviewed. The importance of proper sampling is discussed. Fat contents of 2.6–4.5% and cholesterol amounts of 200–650 mg/100 g fat were reported. The phytosterols in milk were increased by the consumption of these sterols. Phytosterols could contribute to the “total cholesterol” in milk if analyses are done colorimetrically. The fatty acid composition is remarkably uniform unless bizarre diets are consumed; the amounts of linoleic acid vary the most. Phospholipids contained more long chain polyunsaturated fatty acids than triacylglycerols.
Effect of oxidized oil on lipogenic enzymes
Authors: Iritani Nobuko , Fukuda Eiko , Kitamura Yohko
Published: November 2006

Male Wistar rats were fed for 4 wk on diets containing 2% oxidized corn oil. Liver tissue was then studied to determine the effect of feeding peroxidized oil on lipogenic enzymes. Although substances which reacted with thiobarbituric acid increased in liver microsomes and mitochondria with increasing peroxide values of the dietary corn oil fed, the activities of glucose‐6‐phosphate dehydrogenase, malic enzyme and acetyl‐CoA carboxylase in liver were unchanged. However, when rats were fed for 2 wk on diets containing 10% fat, of which 0.5, 5 or 10% was unoxidized corn oil and the remainder was hydrogenated beef tallow filler, the lipogenic enzyme activities and also the liver triglyceride levels were observed to decrease with increasing amounts of dietary corn oil. Therefore, although a synthetic diet containing corn oil was easy to oxidize spontaneously, the reductions of lipogenic enzymes in rats fed the diet would not have been caused by lipid peroxides but by unsaturated fatty acids themselves.
Isolation and partial characterization of the neutral glycosphingolipids and gangliosides of the human heart
Authors: Levis G. M. , Karli J. N. , Moulopoulos S. D.
Published: November 2006

The glycosphingolipids (GLS) of the human heart muscle have been isolated from total lipids by column and thin layer chromatography and their sugars and fatty acids analyzed by gas liquid chromatography. Hearts from traffic victims were obtained at autopsy between 12 and 16 hr after death and dissected into parts (left and right ventricular walls, intraventricular septum and papillary muscle). The neutral GSL content for those parts of the hearts of two males aged 22 and one female aged 14 ranged from about 90 to 160 nmoles/g wet weight. Trihexosyl ceramide and globoside were the most abundant neutral GSL. Total ganglioside content was about 50 nmoles/g wet weight, and the most abundant gangliosides were partially characterized as GM3 and GM1; other mono‐, di‐ and trisialogangliosides were also present. Differences in the content and composition of neutral GSL and gangliosides between the heart and other human tissues are discussed. It is concluded that the patterns of these two GSL fractions of the heart are more complex than those of most of the extraneural human tissues.
A comparison of the ganglioside distributions of fat tissues in various animals by two‐dimensional thin layer chromatography
Authors: Ohashi Masako
Published: November 2006

The ganglioside distributions of various fat tissues from human, rabbit, rat, mouse, chicken and frog were compared with pig adipose gangliosides by two‐dimensional thin layers chromatography. It was found that there is a remarkable species variation in ganglioside distribution, especially in the composition and relative concentration of complex gangliosides. Differing from pig adipose tissues, those of human, rabbit, rat, mouse, chicken, but not frog, contained GM3 as a most abundant ganglioside. The data for human, rabbit and chicken indicated a simple distribution of only NeuActype gangliosides, while those for rat and mouse indicated a rather complicated pattern containing both NeuAc‐ and NeuGc‐type gangliosides. The ganglioside pattern of the frog fat body differed markedly from those of mammalian fat tissues because of the presence of three different, unsual monosialosylgangliosides as major components. In other respects, a substantial amount of disialosylgangliosides was commonly found in all animal fat tissues.
13C nuclear magnetic resonance of mono‐and dihydroxy saturated and unsaturated fatty methyl esters
Authors: Rakoff Henry , Weisleder David , Emken Edward A.
Published: November 2006

13C nuclear magnetic resonance spectra were obtained for methyl esters oferythro‐ andthreo‐9,10‐dihydroxystearates, for 12‐hydroxy‐cis‐ andtrans‐9‐octadecenoates, and forthreo‐12,13‐dihydroxy‐cis‐andtrans‐9‐octadecenoates.Erythro andthreo compounds may be distinguished easily by the difference in the chemical shifts of the carbons alpha to the hydroxy‐bearing carbons. Monohydroxy compounds are easily distinguished fromvicinal dihydroxy compounds by differences in chemical shifts of both the hydroxy‐bearing carbons and of the carbons alpha to them. The presence of a hydroxy‐bearing carbon beta to a double bond results in the two carbons of the double bond of a hydroxy‐bearing carbon beta to a double bond results in the two carbons of the double bond having different chemical shifts, with the numerical values being different for thecis andtrans isomers. The chemical shift of a carbon alpha to both a doubly bonded carbon and a hydroxy‐bearing carbon is influenced both by the geometry of the double bond and the number of hydroxy‐bearing carbons.
Serum high density lipoprotein and its relationship to cardiovascular disease risk factor variables in children—The bogalusa heart study
Authors: Berenson Gerald S. , Srinivasan Sathanur R. , Frerichs Ralph R. , Webber Larry S.
Published: November 2006

Serum high density lipoprotein is increasingly recognized as a negative risk for cardiovascular disease. The distribution and interrelationship of serum lipids, lipoproteins, anthropometric measurements and blood pressures were determined in some 5,000 children. Children had mean±S.D. α‐lipoprotein cholesterol levels (mg/100 ml) of 36±15 at birth, 51±22 at 6 mo, 53±18 at 1 yr, 60±19 at preschool age (21/2−51/2 yr) and 68±22 at school age (5–14 yr), reflecting a sharp increase in α‐lipoprotein between birth and school‐age years, when these levels remained relatively stable through age 14. Although white children tended to have higher levels of total cholesterol and α‐lipoprotein at birth than black children, during childhood this trend was reversed and the differences were pronounced in school‐age children (p<0.0001). Unlike in adulthood, boys had slightly higher levels of α‐lipoprotein than girls. The α‐lipoprotein was negatively correlated with pre‐β‐lipoprotein and to a lesser extent with β‐lipoprotein classes. There was an inverse relationship between α‐lipoprotein and obesity with a consistently significant relationship (p<0.01) in older children (10–14 yr). Children with higher levels of α‐lipoprotein have lower levels of blood pressure, β‐lipoprotein and a lower obesity index.
High and low density lipoprotein cholesterol levels in hypercholesterolemic school children
Authors: Morrison John A. , de Groot Ido , Kelly Kathe A. , Edwards Brenda K. , Mellies Margot J. , Tillett Sandra , Khoury Phillip , Glueck Charles J.
Published: November 2006

To most fully explicate risk to coronary heart disease (CHD) in adults and children with elevated plasma total cholesterol, the levels of high and low density lipoprotein cholesterol (C‐HDL, C‐LDL) must be quantitated. This report focuses upon C‐HDL and C‐LDL levels in children identified in a lipid and lipoprotein sampling survey of 6,775 Princeton School children, by either total plasma cholesterol ≥205 mg/dl, the approximate 95th percentile for children 6–17 years of age, or age‐, sex‐, and race‐specific 95th percentiles for cholesterol. Using the sex‐, race‐specific local 95th percentiles for C‐HDL and C‐LDL, the hypercholesterolemic children were separated into four categories according to whether they had elevations of both C‐HDL and C‐LDL, C‐HDL only, C‐LDL only, or neither. When selection for hypercholesterolemia was based on the overall 95th percentile (205 mg/dl), black children were more likely than white to have elevations of C‐HDL only, which accounted for their hypercholesterolemia, p<.05, whereas white children were much more likely to have elevations of C‐LDL only, than were black children, p<.005. However, when selection for hypercholesterolemia was based on age‐, sex‐, and race‐specific 95th percentile cholesterol levels, there were no differences in the proportion of black and white children having elevations of C‐HDL and C‐LDL, accounting for their hypercholesterolemia. Elevated levels of C‐HDL can explain apparent hypercholesterolemia in at least 16% of children, ages 6–17, who may putatively be at reduced, rather than increased CHD risk.
Relative utilization of fatty acids for synthesis of ketone bodies and complex lipids in the liver of developing rats
Authors: Yeh Y. ‐Y. , Streuli V. L. , Zee P.
Published: November 2006

The regulation of hepatic ketogenesis, as related to the metabolism of fatty acids through oxidative and synthetic pathways, was studied in developing rats. [1‐14C] palmitate was used as a substrate to determine the proportions of free fatty acids utilized for the production of ketone bodies, CO2 and complex lipids. Similar developmental patterns of hepatic ketogenesis were obtained by measuring the production of either [14C]acetoacetate from exogenous [1‐14C] palmitate or the sum of unlabeled acetoacetate and β‐hydroxybutyrate from endogenous fatty acids. The production of total ketone bodies was low during the late fetal stage and at birth, but increased rapidly to a maximum value within 24 hr after birth. The maximal ketogenic capacity appeared to be maintained for the first 10 days of life.14CO2 production from [1‐14C] palmitate increased by two‐ to fourfold during the suckling period, from its initial low rate seen at birth. The capacity for synthesis of total complex lipids was low at birth and had increased by day 3 to a maximal value, which was comparable to that of adult fed rats. The high lipogenic capacity lasted throughout the remaining suckling period. When ketogenesis was inhibited by 4‐pentenoic acid, the rate of synthesis of complex lipids did not increase despite an increase in unutilized fatty acids. During the mid‐suckling period, approximately equal amounts of [1‐14C] palmitate were utilized for the synthesis of ketone plus CO2 and for complex lipid synthesis. By contrast, in adult fed rats, the incorporation of fatty acids into complex lipids was four times higher than that of ketone plus CO2. These observations suggest that stimulated hepatic ketogenesis in suckling rats results from the rapid oxidation of fatty acids and consequent increased production of acetyl CoA, but not from impaired capacity for synthsis of complex lipids.
Delayed conversion of squalene to sterols during development ofPinus pinea seeds
Authors: McKean Margaret L. , Nes William R.
Published: November 2006

During germination of seeds of the gymnosperm,Pinus pinea, radioactivity from [2‐14C]‐mevalonate proceeded principally through the anaerobic reactions leading to squalene in the first 24 hr in both the haploid endosperm and the diploid embryo, and only with succeeding time (3–9 days) in both cases was label transferred to sterols in oxygen‐requiring steps. The rates of turnover must be real and independent in the two tissues, since no consequential interchange of labelled lipids occurred between the endosperm and the embryo. Similar delayed conversion of squalene to sterols has been observed previously during germination of seeds of the angiosperm,Pisum sativum.
Antioxidants in neoplastic cells: II. Isolation and partial characterization of a phenolic antioxidant from differentiated mouse neuroblastoma cells
Authors: Arneson Richard M. , Wander Joseph D.
Published: November 2006

The generation of an antioxidant has been shown to be associated with the dramatic increase in resistance to lipid peroxidation which occurs during the differentiation of mouse neuroblastoma cells in culture. The antioxidant has been isolated from the neuroblastoma neutral lipid fraction and partially characterized by means of low‐resolution and high‐resolution mass spectrometry and other lines of evidence. All presently available information suggests that this antioxidant is a highly aromatic, monosubstituted phenol having the molecular formula C19H14O2.
Synthesis of acyl‐S‐pantetheine by rat liver microsomes
Authors: Sribney Michael , Dove Jerre L.
Published: November 2006

The synthesis of acyl‐S‐pantetheine was found to occur in rat liver microsomal preparations. The reaction required ATP and a metal ion as cofactors, a fatty acid and the reduced form of pantetheine for optimal activity. The Km for pantetheine was 0.8 mM, for ATP 0.8 mM, and for oleic acid 0.3 mM. Mg2+ (20 mM), Mn2+ (5 mM), Ca2+ (5 mM), and Fe2+ (5 mM) produced approximately equal activity when all other conditions were optimal. The characterization of the product and other properties of the enzyme are described. The acyl‐S‐pantetheine formed does not act as an acyl donor in the acylation ofsn‐glycerol‐3‐phosphate, 1,2‐diacylglycerol, or lysolecithin.
1,2‐Propanediol‐induced changes in plasma and tissue lipids of rats
Authors: Amma M. K. P. , Dani H. M. , Ahluwalia Pushpa , Dhingra Aruna , Kaur Jaswinder , Kaur Charanjit , Sharma Sushma , Jain Kamlesh , Singh Sarvpreet , Sareen K.
Published: November 2006

Oral administration of 1,2‐propanediol to rats in a daily dose of 1 ml of 28.4% aqueous solution per 100 g body weight for 30 days caused a significant decrease in the total lipids, fatty acids, phospholipids, and triglycerides of plasma, liver, and heart, The cholesterol content in plasma decreased while that in the tissues increased significantly. The accumulation of cholesterol in tissues tends to discourage long term use of 1,2‐propanediol even by the oral route.
The acylation of 1‐palmitylglycerol 3‐phosphate withCis andTrans C‐16 to C‐22 monoenoic fatty acids in rat liver microsomes
Authors: Marchand C. M. , Beare‐Rogers J. L.
Published: November 2006

The configurational specificity of acyl‐CoA: 1‐palmitylglycerol 3‐phosphate acyltransferase from rat liver microsomes was investigated withcis andtrans C‐16, C‐18, C‐20, and C‐22 monoenoic and saturated fatty acyl‐CoA. Oleyl‐CoA was transferred three times more readily than elaidyl‐CoA. Elaidyl‐CoA was more inhibitory than oleyl‐CoA, especially at low protein concentrations, but did not show this effect after the addition of 1 mg/ml bovine serum albumin (BSA). BSA permitted linearity of the acyltransferase over a wide range of protein concentrations and did not seem to affect the configurational specificity of the acyltransferase. The specificity of the enzyme preparation was in the following decreasing order: 18∶1cis>16∶1cis≅16∶0>18∶0≅16∶1trans>18∶1trans>20∶1cis>20∶1trans. The enzyme preparation did not react withcis ortrans 22∶1 acyl‐CoA.
Reduction in medium chain acids and monoenoic acids in livers and plasma of rats fed eicosa‐5,8,11,14‐tetraynoic acid
Authors: Rao G. Ananda , Siler Kathleen , Larkin Edward C.
Published: November 2006

Male Sprague‐Dawley rats were fed for 8 weeks a corn oil (CO) diet or a hydrogenated coconut oil (HCNO) diet. These diets were fed in the absence or presence of eicosa‐5,8,11,14‐tetraynoic acid (TYA). The inclusion of TYA in the HCNO diet reduced the levels of 12∶0 and 14∶0 in the total fatty acids of livers and plasma. With either diet, the presence of TYA caused an alteration in the fatty acid composition of these tissues so as to reduce the values of the ratios: 16∶1/16∶0, 18∶1/18∶0, and 20∶4/18∶2. These results suggest that dietary TYA can influence the hepatic metabolism of medium chain fatty acids and that it may inhibit the desaturase enzyme involved in the synthesis of not only 20∶4 but also of monoenoic fatty acids.
Dietary factors in arteriosclerosis: Sucrose
Authors: Yudkin John
Published: November 2006

Epidemiological studies show that coronary heart disease is more common in wealthier countries than in poorer. Such studies cannot, however, isolate which of the dietary or nondietary characteristics of affluence help to cause the disease; they provide only clues that need to be subjected to experimental study. Experiments should be designed on the basis of their ability to produce the multiple abnormalties associated with coronary heat disease (CHD) and not only hypercholesterolemia. They should also explain the association of CHD with obesity, diabetes mellitus, cigarette smoking, and physical inactivity. These considerations suggest that the underlying abnormality that produces CHD is a disturbed hormonal balance. Experiments have shown that a high consumption of sucrose produces not only the wide range of abnormalities seen in CHD but also an increased blood concentration of insulin and cortisol. Since a low intake of sucrose confers many other health benefits, it is a more logical dietary recommendation than that of substituting polyunsaturated fat for saturated fat.
Arylsulfonate esters of fatty alcohols: IV. Effects on cholesterol catabolism
Authors: Klauda Harry C. , Bell Frank P. , Grogan W. McLean , Quackenbush Forrest W.
Published: November 2006

Hypercholesterolemic rats, fed 1% cholesterol and 0.5% glycocholate, were treated with arylsulfonates in various ways to observe the pattern of cholesterol elimination. Dietary linoleyl p‐toluene‐sulfonate (LTS) hastened return to normocholesterolemia and lowered hepatic cholesterol either with or without continued cholesterol feeding. LTS administered via the portal vein significantly lowered plasma cholesterol in 48 hr; ethyl linoleate and monoolein produced no lowering. LTS administered via the portal vein to glycocholate‐infused rats increased the biliary excretions of label from [4‐14C]cholesterol administered intracardially and also increased total bile acid excretion 21% without increased bile volume when compared to similar injection of ethyl linoleate. No change in biliary excretion of cholesterol was seen. Bile acid kinetics were studied by using isotopic dilution techniques. Cholate turnover was enhanced by feeding oleyl p‐toluenesulfonate (OTS) and oleylp‐(n‐decyl)‐benzenesulfonate (ODS) as suggested by a 16–35% decrease in half‐life in both normal and hypercholesterolemic rats. Rats consuming a grain‐based colony diet had a 54% increase in cholate synthesis when OTS was included in the diet. The composition of bile was changed when either OTS or ODS was fed; an increase in chenodeoxycholate was noted. This change was gradual with OTS but rapid with ODS and paralleled enhanced decay of chenodeoxycholate specific radioactivity in response to treatment. ODS and OTS also increased14CO2 expiration from oral [26‐14C] cholesterol in hypercholesterolemic rats. Dietary OTS and ODS elevated hepatic free cholesterol in hypercholesterolemic rats; ODS also elevated plasma free cholesterol and increased cholesteryl ester hydrolase activity in the liver. The data suggest that arylsulfonates stimulate cholesterol catabolism, in addition to the reported inhibition of cholesterol absorption [Lipids 12:819 (1977)].