bluuebunny/crossref_metadata_2025 huggingface dataset:
Composition and biosynthesis of fatty acids inPyramimonas grossii
Authors: Pollero Ricardo J. , Brenner Rodolfo R. , Gayoso Ana María
Published: November 2006

The green algaPyramimonas grossii orginating in the coastal waters of the Atlantic Ocean Argentina was subcultured until a monoalgal culture was obtained. The fatty acid composition of the alga grown in a mineral medium at 12 C was determined by gas liquid chromatography (GLC) on 2 columns. The major fatty acids were oleic, linoleic, palmitic and α‐linolenic acids, but the 20‐carbon polyunsaturated acids, 20∶4ω6 and 20∶5ω3, respectively, belonging to the linoleic and α‐linolenic series, were also found. Incubation with [14C] oleate, [14C] acetate, [14C] linoleate and [14C] α‐linolenate suggests that linoleate is not directly converted to α‐linolenate. [14C] Acetate was easily converted to palmitic, palmitoleic and oleic acids. However, after 48 hr of incubation, only traces of radioactivity were detected in linoleic acid and no label was found in α‐linolenic acid.
The removal of peroxides from phosphatidylcholine preparations
Authors: Poghossian G. G. , Nalbandyan R. M.
Published: November 2006

A major portion of the peroxides from egg yolk phosphatidylcholine preparations can be removed by filtration through Sephadex LH‐20, by repetitive suspending of phosphatidylcholine preparations in water, precipitation by acetone and brief incubation of the lipid with superoxide dismutase.
A convenient spectrophotometric assay for phospholipase D usingp‐nitrophenyl‐phosphocholine as substrate
Authors: Gupta Munishwar N. , Wold Finn
Published: November 2006

A simple assay for plant phospholipase D is described. The enzyme hydrolyzesp‐nitrophenyl‐phosphocholine top‐nitrophenyl phosphate, which in the presence of an acid phosphatase generatesp‐nitrophenol (a chromogenic compound). Thus,p‐nitrophenylphosphocholine can be used for assay of phospholipase D in sources that do not also contain high levels of phospholipase C.
Major unsaturated cuticular hydrocarbons of the field crickets,Gryllus pennsylvanicus andNemobius fasciatus
Authors: Warthen J. D. , Uebel E. C.
Published: November 2006

Adult male field crickets,Gryllus pennsylvanicus Burmeister, have more unsaturated cuticular hydrocarbons than adult females, and each has more unsaturates than last‐instar male and female nymphs. The 2 most abundant unsaturated hydrocarbons from each adult were (Z)‐7‐nonacosene and (Z,Z)‐6,22‐nonacosadiene. Last‐instar male nymphal field crickets,Nemobius fasciatus (De Geer), were almost devoid of cuticular alkenes compared to last instar female nymphs and adult males and females. The major unsaturated hydrocarbon from each was (Z,Z)‐6,9‐pentacosadiene.
Effect of dietary fat on the fluidity of platelet membranes
Authors: Berlin Elliott , Matusik Edward J. , Young Calvert
Published: November 2006

Dietary fat type was reflected in the phospholipid fatty acid composition of the plasma membrane of rabbit platelets and apparently controlled the fluidity of these membranes. Rabbits were maintained for 6 months on diets that varied in stearic and polyunsaturated fatty acids and thus had different potentials for thrombosis. Microviscosities at 37 C, calculated from the anisotropy of fluorescence from the probe 1,6‐diphenyl‐1,3,5‐hexatriene, were 3.5, 3.4, 2.8 and 2.2. poise for platelet membranes isolated from rabbits whose only source of dietary fat was cocoa butter, milkfat, coconut oil, or corn oil, respectively. The relative fluidities of the membrane isolates were correlated with the polyunsaturated fatty acid contents of the membrane phospholipids.
Fatty acid synthesis in the oil palm (Elaeis guineensis): Incorporation of acetate by tissue slices of the developing fruit
Authors: Oo Khaik‐Cheang , Teh Sau‐Keen , Khor Hun‐Teik , Ong Augustine S. H.
Published: November 2006

Oil palm (E. guineensis) fruits at three stages of development were studied. At week 12–13 after anthesis, the endosperm had started accumulating oil and tissue slices incorporated [1‐14C] acetate into fatty acids which resembled those found in the mature endosperm. The mesocarp contained very little oil and incorporated acetate into polar lipids. At week 16–17, the mesocarp started to accumulate oil; this was reflected in the [14C] lipid products from acetate incubation. At or just prior to this stage, an increase in the endogenous linoleic and linolenic acid content and the increase in fruit size indicated cellular growth in the mesocarp tissue. At week 20–21 the fruit was ripe, and both endosperm and mesocarp tissues were filled with storage oil. [14C] Fatty acids synthesized from acetate by mesocarp slices at this stage were the same as the endogenous storage fatty acids in bothE. guineensis andE. oleifera. A very weak fatty acid synthesizing activity was seen in the mature endosperm, but the products had no relationship to the storage lipid.
Chylomicron‐like particles in severe hypertriglyceridemia
Authors: Aviram Michael , Sechter Yael , Brook J. Gerald
Published: November 2006

Plasma lipoproteins in a diabetic patient with severe hypertrigly ceridemia and turbid, milky plasma were studied and compared with those found in three primary type V hyperlipoproteinemic and in three normal subjects after a fatty meal. All subjects had normal post‐heparin lipolytic activity. Lipoprotein electrophoresis of the patient's plasma revealed no chylomicron band, and upon short‐time ultracentrifugation the patient's supernatant showed most lipid staining in the pre‐β‐lipoprotein region. This supernatant, which in type V hyperlipoproteinemia as well as in normal subjects after a fatty meal, contains a large proportion of apolipoprotein B‐48 (of intestinal origin) was found in our patient to contain mostly apolipoprotein B‐100 (of liver origin). Upon incubation of normal washed platelets with chylomicrons derived either from type V hyperlipoproteinemic or from normal subjects after a fatty meal, platelet aggregation was decreased, whereas the chylomicron‐like particles from the patient increased platelet activity. It is, thus suggested that the triglyceride‐rich cholesterol‐poor lipoproteins are of liver and not of intestinal origin.
Metabolism and cholestatic effect of 3α‐hydroxy‐7ζ‐methyl‐5β‐cholanoic acid
Authors: Une Mizuho , Mosbach Erwin H. , Cohen Bertram I. , May‐Donath Patricia , McSherry Charles K.
Published: November 2006

3α‐Hydroxy‐7ζ‐methyl‐5β‐cholanoic acid (7ζ‐methyl‐LA) was infused intravenously into bile fistula hamsters to investigate its metabolism and effect on the bile flow as compared with lithocholic acid. Following infusion of the labeled bile acids, bile was collected quantitatively to allow measurement of bile flow and bile acid composition. More than 80% of radioactivity was recovered in bile within 4 hr. 7ζ‐Methyl‐LA and lithocholic acid in bile were present as the taurine and glycine conjugates; no free bile acids were detected. 7ζ‐Methyl‐LA was neither hydroxylated nor metabolized to any measurable extent, though lithocholic acid was 7α‐hydroxylated to chenodeoxycholic acid (30–45%).

At the infusion rate at which lithocholic acid induced a severe cholestasis (264 nmol/min), 7ζ‐methyl‐LA did not decrease the bile flow. In fact, the infusion of 7ζ‐methyl‐LA produced a mild choleresis under conditions where endogenous bile acid excretion was not changed appreciably compared to control infusions with albumin.

It is concluded that 7ζ‐methyl‐LA is not metabolized in the hamster but is conjugated with taurine and glycine, and that the introduction of a methyl group at the 7‐position of lithocholic acid appears to alleviate the cholestatic effect of lithocholic acid in the hamster.
Synthesis of octadecynoic acids and [1‐14C] labeled isomers of octadecenoic acids
Authors: Valicenti A. J. , Pusch F. J. , Holman R. T.
Published: November 2006

Geometric and positional isomers of [1‐14C] octadecenoic acids have been synthesized by modifications of published procedures. Positional isomers of octadecynoic acids also have been synthesized to obtain the geometric and positional isomers of the unlabeled octadecenoic acid analogs. The syntheses were accomplished by coupling a haloalkyl compound with a substituted acetylene using n‐butyl lithium in hexamethylphosphoramide. The coupled product, either a 17‐or 18‐carbon acetylenic alcohol, could be semihydrogenated and chain extended to afford a carboxy labeled derivative, could be partially hydrogenated and chain extended to afford a carboxyl labeledcis‐ortrans‐octadecenoic acid in the former case. In the latter case, octadecynoic,cis‐octadecenoic ortrans‐octadecenoic acids could be obtained by the appropriate reactions. The methods used in this study enabled the synthesis of14C‐labeled fatty acids in generally higher yields and by simpler reactions than were previously possible.
The chemistry of lipid peroxidation metabolites: Crosslinking reactions of malondialdehyde
Authors: Nair Vasu , Cooper Curt S. , Vietti David E. , Turner Gregory A.
Published: November 2006

Malondialdehyde reacts readily with amino acids to form adducts containing vinylogous amidine linkages. Crosslinking reactions between nucleic acid bases, and amino acids induced by malondialdehyde also have been investigated. The physical data obtained for the adducts provide structural information on the possible mode of crosslinking of proteins and nucleic acids induced by this lipid metabolite.
HPLC measurement of testicular long chain acyl‐CoA synthetases with different substrate specificities
Authors: Grogan W. McLean , Huth Ellen G.
Published: November 2006

Acyl‐CoA synthetase activity with various long chain fatty acid substrates was measured in microsomes from rat testes, isolated spermatids and testes of hypophysectomized adult rats, using reversed‐phase high performance liquid chromatography (HPLC). The spectrophotometric HPLC method produced results comparable to those of parallel radiometric assays and was highly specific for acyl‐CoA products. At optimal pH and cofactor concentrations, specific activity from whole testis was similar for 18∶1, 20∶4 and 22∶5 but somewhat lower for 16∶0 over the substrate range 0.01–3.2 mM. Activity from spermatids or from testes of hypophysectomized rats was much lower with 22∶5 than with 18∶1 or 20∶4, whereas activities with 18∶1 and 20∶4 were similar at all substrate concentrations. All substrates exhibited Michaelis‐Menten type saturation kinetics and linear Lineweaver‐Burke plots at lower substrate concentrations but inhibited activity at higher concentrations. Apparent values of KM for 16∶0, 18∶1 and 20∶4 were more than twice that of 22∶5, whereas both observed and calculated maximum velocities were similar for the four fatty acids. Differences in pseudokinetic parameters and differential expression of the testicular acyl‐CoA synthetase activities with different fatty acids suggest the presence of multiple enzymes, at least one of which may be hormonally regulated.
Design of high energy intermediate analogues to study sterol biosynthesis in higher plants
Authors: Rahier Alain , Taton Maryse , Bouvier‐Navé Pierrette , Schmitt Paulette , Benveniste Pierre , Schuber Francis , Narula Acharan S. , Cattel Luigi , Anding Claude , Place Pierre
Published: November 2006

Several enzymes of plant sterol biosynthesis involve during their catalysis postulated or demonstrated carbocationic high energy intermediates (HEI). The aim of this study was to interfere with plant sterol biosynthesis by means of rationally designed species able to mimic these carbocationic HEI. It has been demonstrated previously that the design of transition state (TS) or HEI analogues could lead to powerful and specific inhibitors of enzymes. We applied this approach to the following target enzymes: 2,3‐epoxy‐2,3‐dihydroqualene cyclase, AdoMet‐cycloartenol‐C‐24‐methyltransferase (AdoMet CMT), cycloeucalenol‐obtusifoliol isomerase (COI) and Δ8‐Δ7‐sterol isomerase. Very potent inhibitors have been obtained in the four cases. As an example, analogues of cycloartenol substituted at C‐25 by a charged heteroatom (N, As, S) have been synthesized and shown to be able to mimic the C‐25 carbocationic HEI involved in the reaction catalyzed by the AdoMet CMT. These compounds were shown to be very potent and specific inhibitors of this enzyme both in vitro (Ki=2.10−8 M, Ki/Km=10−3) and in vivo. The potent inhibitors described are powerful tools to control in vivo the sterol profile of plant cells and therefore to study the structural and functional roles of sterols in cell membranes. Moreover, these compounds constitute leader molecules of a new class of rationally designed inhibitors which could be of value in plant protection.
The role of phytosterols in host plant utilization by cactophilicDrosophila
Authors: Fogleman James C. , Duperret Susann M. , Kircher Henry W.
Published: November 2006

The Cactus‐Drosophila Model System of the Sonoran Desert consists of four endemic species ofDrosophila (D. mojavensis, D. nigrospiracula, D. mettleri andD. pachea) and five species of columnar cacti (agria, organpipe, saguaro, cardón and senita). Extensive collection records indicate that each cactus species has only one species ofDrosophila as the primary resident. The elimination of six of the twenty possible random combinations ofDrosophila species and cactus species can be attributed directly to phytosterols.Drosophila pachea has a strict requirement for Δ7‐sterols such as 7‐cholestenol and 7‐campestenol. Since Δ7‐sterols are found only in senita cactus,D. pachea cannot use agria, organpipe, saguaro or cardón as host plants. The lipid fractions of agria and organpipe are chemically similar and contain high concentrations of several 3β,6α‐dihydroxysterols. Larval viability tests using chemical constitutents of organpipe cactus demonstrate that the sterol diols are toxic toD. nigrospiracula but not to the resident, species,D. mojavensis. Agria and organpipe are therefore unsuitable as host plants forD. nigrospiracula. These results suggest that phytosterols play a major role in determining host plant utilization by cactophilicDrosophila in the Sonoran Desert.
Fatty acid synthesis in vivo and hepatic contribution to whole‐body lipogenic rates in obese zucker rats
Authors: Kannan R. , Learn D. B. , Baker N. , Elovson J.
Published: November 2006

We have re‐examined the claim by Godbole and York, based on the effect of surgical hepatectomy (Diabetologia14∶191, 1978), that liver contributed more than 90% of the newly synthesized FA found in adipose tissue of obese rats at the end of a 1‐hr pulse of3H2O. The amount of newly synthesized FA transported via plasma VLDL from liver to adipose tissue was estimated in lean and obese Zucker rats by determining the effects of Triton WR‐1339, which blocks the uptake of VLDL‐TGFA into tissues. Triton treatment was found not to cause any significant change in the amount of radioactive FA found in subcutaneous/perimetrial fat tissues, carcass or liver in either chow‐fed or high‐glucose, fed‐refed lean or obese rats, although in the fed‐refed dietary state the proportion found in the liver was increased over that in the chow‐fed groups. Furthermore, the amounts of newly made FA which accumulated in the plasma of Triton‐treated, chow‐fed and glucose‐fed refed animals during this period constituted only a few percentages of those found in the adipose tissue of these animals. Thus, in contrast to the claims of Godbole and York, no significant transfer of newly made FA from liver to adipose tissue occurs during a 1‐hr experiment; it follows that the amounts of these FA found in different tissues at the end of that period are valid measurements of their actual lipogenic activities in situ. It is suggested that the Godbole and York results are artifacts of their surgical hepatectomy procedure.
Placental transport oftrans fatty acids in the rat
Authors: Moore Carolyn E. , Dhopeshwarkar Govind A.
Published: November 2006

Placental transport of 9‐trans [1‐14C] octadecenoic (elaidic) and 9‐trans,12‐trans [1‐14C] octadecadienoic (linoelaidic) acids was demonstrated in rats. On the 18th day of gestation, a14C‐labeled albumin complex of elaidic or linoelaidic acid was injected into the jugular vein of pregnant rats. For comparison, 9‐cis [1‐14C] octadecenoic (oleic) or 9‐cis,12‐cis [1‐14C] octadecadienoic (linoleic) acid also was injected into the maternal circulation of rats. All animals were sacrificed 1 hr following injection. Lipid composition and distribution of label were determined in maternal plasma, placental and fetal tissues. Differences in specific activities of plasma, placental and fetal total lipids indicated a decreasing concentration gradient for bothcis andtrans isomers of octadecenoic and octadecadienoic acids. Distribution of radioactivity in various lipid components was determined by thin layer chromatography. Irrespective of the label, the highest percentage of total radioactivity was carried by triglycerides (TG) in maternal plasma (∼60–80%), and was incorporated mainly in phospholipids (PL) of fetal tissues (∼50–60%). A nearly equal distribution of the label was found between PL and TG of placental lipids (∼40%). Radioactivity of fatty acid methyl esters (FAME) determined by radiogas liquid chromatography indicated that after injection of linoelaidate, radioactivity of maternal plasma, placental and fetal tissue FAME was associated only witht,t‐18∶2. Following injection of elaidate, all the radioactivity in placental FAME was associated witht‐18∶1; however, in fetal tissues, the label was distributed between 16∶0 andt‐18∶1. These findings suggest that, in contrast to linoelaidic acid, rat fetal tissues can metabolize elaidic acid via β oxidation to form acetyl CoA and palmitic acid.
Effects of dietarytrans acids on the biosynthesis of arachidonic acid in rat liver microsomes
Authors: Kurata Norimasa , Privett Orville S.
Published: November 2006

Effects of dietarytrans acids on the interconversion of linoleic acid was studied using the liver microsomal fraction of rats fed a semipurified diet containing fat supplements of safflower oil (SAFF), hydrogenated coconut oil (HCO) at 5 and 20% levels or a 5% level of a supplement containing 50.3% linolelaidic and 24.3% elaidic acids devoid ofcis,cis‐linoleic acid (TRANS). Growth rate was suppressed to a greater extent with the animals fed the 20% than the 5% level of the HCO‐supplemented diets and still further by the TRANS diet compared to the groups fed the SAFF diets. Food intake was greater in the groups fed the HCO than the SAFF‐supplemented diets, demonstrating the marked effect of an essential fatty acid (EFA) deficiency on feed efficiency. In contrast to an EFA deficiency produced by the HCO supplement, which stimulated the in vitro liver microsomal biosynthesis of arachidonic acid, diets containing the TRANS supplement exacerabated the EFA deficiency and depressed 6‐desaturase activity of the liver microsomal fraction. The liver microsomal fraction of the animals receiving this supplement also was more sensitive to fatty acid inhibition of the desaturation of linoleic acid than those obtained from animals fed either the SAFF or HCO diets. It is suggested that dietarytrans acids alter the physical properties of the 6‐desaturase enzyme system, suppressing its activity, which increases the saturation of the tissue lipids and, in turn, the requirement for EFA or polyunsaturated fatty acids.
The preparation and characterization of the methoxy derivatives of polyunsaturated fatty acids: Stabilized product analogs of lipoxygenase catalysis
Authors: Funk Max O. , Levison Bruce , Keller Maggie B.
Published: November 2006

The products from the action of soybean lipoxygenase on a series of polyunsaturated fatty acids have been converted in 2 steps into the corresponding methoxy derivatives. The product hydroperoxides were reduced in situ to alcohols with sodium borohydride. The ethers were generated by treatment of the alcohols with sodium hydride and methyl iodide in tetrahydrofuran. 13‐Methoxy‐9(Z),11(E)‐octadecadienoic, 15‐methoxy‐11(Z),13(E)‐eicosadienoic and 15‐methoxy‐5(Z),8(Z),11(Z), 13(E)‐eicosatetraenoic acids were thus prepared. The methyl ethers were analyzed and the structures established by high performance liquid chromatography, nuclear magnetic resonance and infrared spectrometry, polarimetry and mass spectroscopy (as methyl esters). The methylation reaction proceeds without molecular rearrangements or racemiziation.
Gangliosides from rat cerebellum: Demonstration of considerable heterogeneity using a new solvent for thin layer chromatography
Authors: Zanetta J‐P. , Vitiello F. , Vincendon G.
Published: November 2006

Using a new solvent (methyl acetate/n‐propanol/chloroform/methanol/0.25% aqueous KCl, 25∶20∶20∶20∶17, v/v) and high performance silica gel thin layer chromatographic plates, all common gangliosides found in brain can be easily separated with 1 hr. This system is reproducible and “tailing” is negligible compared with previous solvents. When such a system is applied to separate the gangliosides found during the development of the rat cerebellum, a considerable heterogeneity is observed. Data are presented (using rechromatography experiments, fractionation on DEAE‐Sephadex, treatment with neuraminidase or alkaline medium and carbohydrate analysis) suggesting that the complex profiles obtained with this chromatographic system are not due to chromatographic artifacts but result from the high resolving power of the system. After separation by ion‐exchange chromatography, 28 gangliosides can be detected.
Heat activation of rat epididymal fat tissue acetyl‐CoA carboxylase is due to dephosphorylation by its endogenous phosphatase
Authors: Krakower Glenn R. , Kim Ki‐Han
Published: November 2006

Acetyl‐CoA carboxylase from rat epididymal fat tissue is activated by incubation at 30 C in the absence of citrate or metal ions. This activation is accompanied by a corresponding loss of32P from the labeled enzyme, and it is not blocked by the heat‐stable phosphorylase phosphatase inhibitor proteins from rabbit muscle. We have succeeded in separating an activity which activates and dephosphorylates acetyl‐CoA carboxylase from the carboxylase using polyethylene glycol‐6000. These results suggest that the temperature‐dependent activation of acetyl‐CoA carboxylase in crude or partially purified preparations results from dephosphorylation of the carboxylase by bound phosphatase.
Long‐term effects of high‐fat diets on peroxisomal β‐oxidation in male and female rats
Authors: Thomassen M. S. , Norseth J. , Christiansen E. N.
Published: November 2006

In weanling male rats a 4‐fold increase of heart triacylglycerols was observed after three days on a high‐fat diet containing partially hydrogenated fish oil (PHFO). In female rats this increase was only about 50%. No significant differences were observed between female and male rats in the fatty acid composition of the accumulated lipids.

The initial level of peroxisomal β‐oxidation activity was similar in male and female rats in both liver and heart. After three weeks of receiving high‐fat diets, the rats showed a marked increase in peroxisomal β‐oxidation activity with PHFO in the diet and less with soybean oil (SO), confirming previous studies with male rats. Catalase activity was similarly affected in hearts of both sexes.

In male rats the levels of peroxisomal β‐oxidation observed after three weeks of feeding on the high‐fat diets were found to be maintained, both in liver and heart, during a feeding period of three months. The response to high‐fat diets in females, however, seems to be further accentuated after three months of feeding, resulting in a capacity of peroxisomal β‐oxidation in liver of about three times that of the male rats when calculated on a total body‐weight basis.
Hypolipidemic activity of the surfactants aminimides, and their effects on lipid metabolism of rodents
Authors: Hall Iris H. , Kabara Jon J. , Matthews Timothy G.
Published: November 2006

A series of short chain fatty acid derivatives of aminimides were shown to possess hypolipidemic activity in rats and mice. Most of the agents tested lowered both serum cholesterol and triglyceride levels by at least 30% in mice and were effective in hyperlipidemic induced mice. 1,1‐Dimethyl‐1‐(2‐hydroxypropyl)‐amine mersitimide lowered serum cholesterol levels 41% and serum triglyceride levels 56% at 20 mg/kg/day I.P. after 16 days. The same agent was active orally when administered to rats with a 38% reduction in serum cholesterol and a 52% reduction in serum triglycerides after 14 days. The agents inhibited liver acetyl CoA synthetase, ATP dependent citrate lyase and phosphatidate phosphohydrolase activities in vitro and in vivo. Reduction of cholesterol, triglycerides, neutral lipids and phospholipid levels were noted in the livers of mice treated for 16 days. In rat studies, cholesterol, triglyceride and phospholipid levels were reduced in liver, small intestine and the feces after two weeks' dosing. The cholesterol content was reduced in the very low density lipoprotein (VLDL) and low density lipoprotein (LDL) fractions but elevated in the high density lipoproteins (HDL). Triglyceride levels were lowered in the VLDL, and neutral lipid levels were reduced in the chylomicron and VLDL fractions.
The distribution and acyl composition of plasmalogens in Guinea pig heart
Authors: Arthur Gilbert , Mock Thomas , Zaborniak Cheryl , Choy Patrick C.
Published: November 2006

In guinea pig heart homogenate, 34% of both choline and ethanolamine phosphoglycerides were in the form of plasmalogens (1‐alkenyl, 2‐acyl glycerophospholipid). Plasmalogens accounted for 39% of the choline phosphoglycerides and 36% of the ethanolamine phosphoglycerides in the mitochondrial fraction. Ethanolamine plasmalogen was the major ethanolamine phosphoglyceride (63%) in the guinea pig heart microsomal fraction. A high arachidonyl content was found in both diacyl and 1‐alkenyl, 2‐acyl glycerophosphoethanolamine. The C‐2 fatty acyl profiles of the diacyl and 1‐alkenyl, 2‐acyl choline phosphoglycerides differed considerably from each other in the homogenate as well as in the subcellular fractions. Significant differences in the C‐2 fatty acyl profiles also were observed in diacyl and 1‐alkenyl, 2‐acyl ethanolamine phosphoglycerides. Such differences suggest there is no direct metabolic relationship between the diacyl glycerophosphocholine (‐ethanolamine) and its plasmalogen analog.
Turnover of phosphocholine and phosphoethanolamine in ether‐phospholipids of krebs II ascite cells
Authors: El Tamer A. , Record M. , Chap H. , Douste‐Blazy L.
Published: November 2006

Krebs II ascite cells suspended in Eagle medium were incubated at 37 C for up to 6 hr in the presence of [3H] glycerol or [32P] orthophosphate. After extraction, their lipids were treated with guinea pig phospholipase A1 under conditions where all diacyl‐phospholipids (diacyl‐PL) became hydrolyzed with 55% recovery of lyso‐PL. Using a bidimensional thin layer chromatography (TLC) involving exposure to HCl fumes between the two runs, it then became possible to determine at once the specific radioactivity of the three subclasses (diacyl‐, alkylacyl‐and alkenylacyl) present in choline glycerophospholipids (CGP) and ethanolamineglycerophospholipids (EGP). Compared to diacyl‐PL, a lower de novo synthesis of ether subclasses was evidenced in both CGP and EGP by [3H] glycerol incorporation. Although the same profile was obtained for CGP with [32P] orthophosphate, the three EGP subclasses displayed in this case the same specific radioactivity.

These data indicate a higher turnover rate of the polar head group of ether‐EGP compared to either‐CGP. The simple methodology used in the present study might thus prove helpful in developing enzymatic studies dealing with the mechanism of this accelerated renewal.
Induced chemiluminescence of oxidized fatty acids and oils
Authors: Neeman I. , Joseph D. , Biggley W. H. , Seliger H. H.
Published: November 2006

The injection of a strong organic base into milligram quantities of fats and oils dissolved in methylene chloride results in a burst of chemiluminescence whose peak intensity is a function of the previous thermal oxidation history and of the degree of unsaturation of the starting material. The flash of this induced chemiluminescence can be 108 times higher than the steady‐state “spontaneous” chemiluminescence. The kinetics of the induced chemiluminescence are first order in concentration and second order in time. The emission spectrum is broad and extends into the near infrared. A model based on dioxetane chemiluminescence is proposed to explain the observed kinetics.
Cholesterol transport and uptake in miniature swine fed vegetable and animal fats and proteis. 1. Plasma lipoproteins and LDL clearance
Authors: Walsh Hentges Lynnette S. , Beitz Donald C. , Jacobson Norman L. , Dare McGilliard A. , Veenhuizen Jeffrey J.
Published: November 2006

In a 2×2 factorial arrangement, miniature pigs were fed four diets containing vegetable protein/fat (soybean) and animal protein (egg white)/fat (beef tallow) to demonstrate the effects of protein and fat source on total plasma cholesterol, lipoprotein distribution, low density lipoprotein (LDL) composition, and plasma clearance of LDL‐cholesterol and protein. Beef tallow consumption resulted in greater plasma cholesterol concentration, decreased LDL‐cholesterol concentration, and a lower LDL‐cholesterol to LDL‐protein ratio than did consumption of soybean oil. High density lipoprotein (HDL)‐cholesterol concentration was increased by beef tallow consumption. Cholesterol percentage by weight in LDL was significantly greater in pigs consuming soybean oil than those consuming beef tallow. Percentages by weight of protein, triglyceride and phospholipid in LDL were not significantly different in any group. Dietary protein source had no significant effect on total plasma cholesterol concentration, lipoprotein concentration or LDL composition. Egg white consumption decreased fractional catabolic rate and irreversible loss of LDL‐cholesterol and LDL‐protein when compared with consumption of soy protein. Dietary fat source had no consistent effect on LDL clearance from plasma. Dietary fat and protein seemed to influence lipoprotein metabolism by different mechanisms. Fat source altered lipoprotein concentration and LDL composition, whereas protein source affected the removal rate of LDL from plasma.
Effect of dietary restriction on the plasma apolipoprotein pattern in cholesterol‐fed rabbits
Authors: Corraze Geneviève , Lacombe Christiane , Nibbelink Maryse
Published: November 2006

Dietary restriction (half of the control ration) was performed in rabbits given either standard or cholesterol‐rich diets. The plasma apolipoproteins were studied on the total, d<1.21, lipoprotein fraction using polyacrylamide gel electrophoresis. A marked rise in the amount of both apo‐B and apo‐E appeared in cholesterol‐fed rabbits and was enhanced by dietary restriction. These results reflect the aggravation of hypercholesterolemia when cholesterol feeding is carried out in underfed rabbits. In all groups only one molecular species of apo‐B, identified as apo‐B‐100, was present after overnight fasting. Thus, lipoproteins which accumulate in the plasma following cholesterol feeding, associated with dietary restriction or not, probably are remnants of hepatogenous triglyceride‐rich lipoproteins.
Cholesterol transport and uptake in miniature swine fed vegetable and animal fats and proteins. 2. LDL uptake and cholesterol distribution in tissues
Authors: Walsh Hentges Lynnette S. , Beitz Donald C. , Jacobson Norman L. , Dare McGilliard A.
Published: November 2006

In a 2×2 factorial arrangement, miniature pigs were fed four diets containing vegetable protein/fat (soybean) and animal protein (egg white)/fat (beef tallow) to demonstrate the effects of protein and fat source on tissue cholesterol concentrations, uptake of intact low density lipoproteins (LDL) and free cholesterol exchange from LDL to tissues. Soybean oil feeding, compared with beef tallow feeding, resulted in greater concentrations of cholesterol in aorta, heart, and large and small intestines. Similar trends were seen in liver, adipose tissue and skeletal muscle. Dietary protein source had little or no effect on tissue cholesterol concentrations. Uptake of intact LDL, as measured by using [14C]sucrose‐LDL, tended to be greater in pigs fed soybean oil or soy protein. Net exchange of free cholesterol from LDL, as measured with [3H]cholesterol, tended to be greater when vegetable products were fed. Relative contributions of whole tissues to total uptake by either mechanism were not influenced by diet. Mechanisms in addition to uptake of cholesterol from LDL seem to be involved in the greater accumulation of tissue cholesterol resulting from polyunsaturated fat feeding.
HPLC of triglycerides with gradient elution and mass detection
Authors: Herslöf Bengt , Kindmark Gunilla
Published: November 2006

A gradient elution reversed phase HPLC system with a mass detector was investigated for the separation of triglycerides. A gradient based on a ternary eluent mixture is suggested. The detector was investigated in terms of linearity, reproducibility and relative response. The separation of soybean oil and some other natural triglyceride mixtures is demonstrated.
Suppression of cholesterogenesis by plant constituents: Review of Wisconsin contributions to NC‐167
Authors: Qureshi A. A. , Burger W. C. , Petterson D. M. , Elson C.
Published: November 2006

In animals, non‐sterol metabolites of the mevalonate pathway act independently from receptor‐mediated cholesterol uptake in the multivalent feedback regulation of mevalonate biosynthesis. Studies leading to the isolation and characterization of plant‐borne suppressors of mevalonate biosynthesis are reviewed. We propose that one cardio‐protective component of the vegetarian diet consists of a variety of non‐sterol, post‐mevalonate metabolites. These products of plant branches of the mevalonate pathway, discarded as animals evolved, continue to influence animal sterol metabolism. It is through this action, we propose, that the cholesterol‐suppressive action of plant materials is expressed.
Cholesterol metabolism in relation to aging and dietary fat in rats and humans
Authors: Dupont Jacqueline , Ewens‐Luby Susan , Mathias Melvin M.
Published: November 2006

A review of research in the authors' laboratories regarding effects of dietary fat polyunsaturation upon longevity in rats and some aspects of the regulation of cholesterol metabolism with regard to age of rats and humans is presented. The longevity of the rat was found to be enhanced by consumption of dietary fat providing a polyunsaturated to saturated fatty acid (P/S) ratio of 0.3 to 1, corresponding to about 5–12% of energy (en%) as linoleate, compared with less or more polyunsaturated fat, mechanisms of the effects of the fats upon cholesterol metabolism were studied. With advancing age, there seems to be a decline in the rate of catabolism of cholesterol, resulting in longer retention in the body of the rat. In the human, there seems to be a decline in regulation of uptake of cholesterol by leukocytes and, therefore, perhaps other tissues, resulting in increased synthesis of cholesterol by the peripheral tissues. Moderate rather than high dietary consumption of polyunsaturated fat seems to be favorable to metabolic processes contributing to longevity.
Absorption and distribution of jojoba wax injected subcutaneously into mice
Authors: Yaron A. , Benzioni A. , More I.
Published: November 2006

14C‐Labeled jojoba wax was injected subcutaneously into mice and14C was determined 1–90 days after application in several internal organs, in the skin and in the lipids extracted from the carcass. A control group of mice was similarly treated with triolein. The major part of the injected lipids was not absorbed or metabolized. Some label was found in the organs examined, but there was no accumulation of labeled lipids with time. About 20% of label derived from triolein was found in polar lipids, whereas only 2–4% of that derived from jojoba wax was found in this fraction. There was some (1–5%) incorporation of the label of jojoba wax into body triglycerides.
Effects of coconut oil on heart lipids and on fatty acid utilization in rapeseed oil
Authors: Bellenand J. F. , Baloutch G. , Ong N. , Lecerf J.
Published: November 2006

Male adult Sprague‐Dawley rats were fed diets containing 15% by weight of sunflower oil, coconut oil, rapeseed oil or combinations of these oils for 5 or 60 days. The digestibility of erucic acid (22∶1), lauric acid (12∶0) and linoleic acid (18∶2) was measured and found to be decreased for erucic acid at both time intervals, and for lauric acid after 60 days when coconut oil and rapeseed oil were blended. The cardiac lipodosis was proportional to the content of erucic acid in the diet. At 60 days, the high level of 22∶6 in the cardiac phospholipids of rats fed rapeseed oil was reduced by the addition of sunflower oil but not by coconut oil. Thus, the blending of rapeseed oil with coconut oil apparently is less desirable than that of rapeseed oil and sunflower oil.
A colorimetric microdetermination of peroxide values utilizing aluminum chloride as the catalyst
Authors: Asakawa T. , Matsushita S.
Published: November 2006

A colorimetric microassay is described for the determination of lipid hydroperoxides. Hydroperoxides are reacted with potassium iodide in the presence of an acid catalyst and liberated iodine is measured. Aluminum chloride, an alcohol‐soluble Lewis acid, is used as catalyst. Liberated iodine is measured colorimetrically at 560 nm after addition of starch in 0.01 N hydrochloric acid. The range of the measurement was 0.05–0.5 μmol of hydroperoxides.
The effects of dietary 9‐trans,12‐rans‐octadecadienoate on composition and fatty acids of rat lungs
Authors: Yu P. , Mai J. , Kinsella J. E.
Published: November 2006

Dietarytrans,trans‐linoleate (trans 18∶2), when fed to rats in increasing amounts, caused a reduction in lung weights, particularly at very high dietary concentrations. The fatty acids of the phospholipids and triglycerides were altered. The percentage of oleic and arachidonic acid decreased as dietarytrans 18∶2 was increased. Eicosatrienoic acid (20∶3) appeared in the phospholipids of lungs from rats receiving 100% dietarytrans 18∶2, but its concentration was much lower than in lungs from rats on an essential fatty acid deficient diet, indicating thattrans 18∶2 inhibited the enzymes synthesizing 20∶3.
The effect of 3‐methylindole on the uptake and incorporation of14C‐choline into phospholipids in lung tissue slices
Authors: Kirkland James B. , Bray Tammy M.
Published: November 2006

3‐Methylindole (3MI) is the causative agent in the development of acute bovine pulmonary edema. Microscopic studies revealed a structural disruption in the lamellar bodies of type II cells, indicating an abnormal metabolism of phospholipid in the lung of 3MI treated animals. In the present study, lung slices from 4 goats were used to investigate the changes in phosphatidylcholine metabolism induced by 3MI. Eighteen slices were cut from each healthy lung and divided into control and 3MI groups. After a 4‐hr pretreatment with 3MI (.19 or .57 mM) or carrier, the level of incorporation of14C‐choline into phosphatidylcholine, sphingomyelin and their water soluble intermediates was studied. The uptake of14C‐choline and its incorporation into phosphatidylcholine and sphingomyelin was depressed by 3MI treatment. In the water soluble fractions, the radioactivity increased in free choline and CDP‐choline while it decreased in P‐choline. This suggests that choline kinase and the P‐choline transferases have become relatively more rate limiting and may play a role in the depressed de novo synthesis of phosphatidylcholine induced by 3MI.
Characterization of a cytosolic protein inhibiting lysosomal acid cholesteryl ester hydrolase
Authors: Tanaka Mitsuo , Yonekura Ryooji , Iio Toshihiro , Tabata Toshikazu
Published: November 2006

An inhibitor of lysosomal acid cholesteryl ester hydrolase (Acid CEH), (EC 3.1.1.13) was found in the cytosolic fraction of rat liver and various other tissues. The extent of the inhibitory effect was dependent on the concentration of the cytosolic protein. The Acid CEH inhibitor was heat‐labile, nondialyzable, and its inhibitory activity significantly decreased by trypsin or chymotrypsin digestion, but not by lipase digestion. The inhibitor had no effect on the activity of cathepsin D, β‐glucuronidase and acid phosphatase, which are other enzymes found in lysosomes. The present findings suggest that the inhibitor may be involved in the regulation of the hydrolysis of cholesteryl esters in lipoproteins that have been transferred into the liver.
Effects of streptozotocin‐induced diabetes on phosphoglyceride metabolism of the rat liver
Authors: Dang An‐Quoc , Faas Fred H. , Carter William J.
Published: November 2006

We have studied the effect of streptozotocin (SZ)‐induced diabetes on fatty acyltransferase and phospholipase enzyme activities involved in the synthesis and degradation of rat liver phosphoglycerides. Neither mitochondrial nor microsomal acyl‐CoA: glycerol 3‐phosphate acyltransferase (GPAT) activity was altered, although insulin treatment stimulated mitochondrial GPAT activity. However, microsomal acyl‐CoA: 1‐acylglycerol 3‐phosphate acyltransferase (1‐acyl‐GPAT) activity increased (24–33 per cent, p<0.01) in the diabetic animals using 3 different acyl‐CoA donors: palmitoyl‐CoA, oleoyl‐CoA and linoleoyl‐CoA. SZ‐induced diabetes also increased acyl‐CoA:1‐acylglycerol 3‐phosphorylcholine acyltransferase (GPCAT) activity (38–45 per cent, p<0.01) with 3 different acyl‐CoA donors: oleoyl‐CoA, linoleoyl‐CoA and arachidonoyl‐CoA. 1‐acyl‐GPAT and GPCAT activity returned to normal with insulin treatment. In contrast to the increased activity of the microsomal fatty acyltransferases 1‐acyl‐GPAT and GPCAT, SZ‐induced diabetes decreased mitochondrial phospholipase A2 activity and lysophospholipase activity (49–70 per cent, p<0.01). Insulin treatment of the diabetic rats corrected the decreased lysophospholipase and stimulated phospholipase A2 activity 35 per cent higher than controls. Since microsomal 1‐acyl‐GPAT and GPCAT are known to have higher activity toward unsaturated fatty acyl‐CoA donors, the increased GPCAT activity coupled with the decreased lysophospholipase activity and the increased 1‐acyl‐GPAT activity in diabetes would tend to increase the formation of newly synthesized phospholipids containing unsaturated fatty acids. This mechanism plus the decreased fatty acid desaturase (4) may be the factors which alter the fatty acid composition of phosphoglycerides in diabetic rat liver microsomes.
The effect of neurotensin on the concentration of cholesterol and bile acids in the guinea pig
Authors: Peric‐Golia Ludvik , Gardner Clark F. , Wilson Dana E. , Peric‐Golia Milena
Published: November 2006

In guinea pigs, total plasma cholesterol concentrations increased above the control values after single intravenous injections and after 3 days of continuous subcutaneous administration of neurotensin (NT). A high dose of NT (125 pmol/100 g body weight) induced tachycardia and severe respiratory distress; the lowest dose (1.25 pmol/100 g body weight) had the greatest hypercholesterolemic effect 15 min after the injections. The bulk of the total plasma cholesterol was in low density lipoprotein fractions. Cholesterol increased in the same fractions after intravenous administrations of NT. NT induced a decrease in the cholesterol content in the ileum but did not affect significantly the cholesterol content in the liver, kidneys or adrenals. In 48‐hr fasted controls, plasma cholesterol concentration and cholesterol content in the liver, kidneys, adrenals and terminal ileum increased; after intravenous injections of NT, plasma cholesterol concentration further increased but cholesterol content of the liver, kidneys and ileum decreased. In fed animals, the concentration of the biliary taurochenodeoxycholic acid increased above the control values 5 and 35 min after the intravenous injections of NT. In fasted controls, the total concentration of bile acids was higher than in fed controls, but only the concentration of taurochenodeoxycholic acid further increased after the injections of NT. Proportionately more taurochenodeoxycholic acid than cholesterol was present in bile after the intravenous injections of NT. These data are consistent with the hypothesis that NT has a regulatory role in intestinal cholesterol transport.
Autoxidation ofAcholeplasma laidlawii membranes
Authors: Wu Guey‐Shuang , Stein Robert A. , Mead James F. , McElhaney Ronald N.
Published: November 2006

Autoxidation ofAcholeplasma laidlawii membranes (with equimolar ratio of palmitic and linoleic acid) lacks an obvious induction period, and the overall rate of disappearance of substrate does not follow closely that of typical autocatalytic kinetics. Throughout the course of autoxidation, the major oxygenated products isolated were hydroperoxides (as hydroxy esters) and compounds that gave rise to trihydroxy esters. The yield of trihydroxy esters was appreciable even at the early stage of the oxidation and eventually grew to surpass that of hydroperoxides. The positions of the three hydroxyl groups in the trihydroxy esters were determined to be mostly of the 1,2,5‐type rather than 1,2,3‐type arrangement. To a lesser extent, some degraded products, including dimethyl nonanedioate, methyl myristate, methyl pentadecanoate, methyl hexadecadienoate and methyl heptadecadienoate also were obtained. Dimethyl nonanedioate was a previously known degradation product from 9‐hydroperoxide. The shorter chain esters presumably arise from the cleavage of α‐hydroperoxides of palmitate and linoleate moieties.
Effect of high doses of synthetic estrogen on lipid metabolism in castrated male rats
Authors: Nishikawa M. , Seki K. , Matsuzawa Y. , Minami Y. , Kawata S. , Miyoshi S. , Imai Y. , Saitoh R. , Noda S. , Tamura S. , Tarui S.
Published: November 2006

The mechanism by which high doses of estrogen influences lipid metabolism was studied with a microtubular blocking agent. Castrated male rats received oral injection daily for 14 days of 3 mg hexestrol in olive oil, or oil alone as controls. About half of the animals in each group were injected intraperitoneally with 4 mg/100 g body weight colchicine 3 hr before they were killed. Hexestrol treatment caused an accumulation of esterified cholesterol in the liver while it decreased those in serum. Triglyceride concentrations slightly decreased in the liver but were unaffected in serum. On polyacrylamide‐gel disc electrophoresis, the peaks of high density lipoproteins (HDL) and low density lipoproteins (LDL) were decreased remarkably. Electron microsopic examination of hepatocytes revealed electron‐lucent lipid droplets in the cytoplasm.

After a colchicine treatment of the control animals, concentrations of esterified cholesterol and triglycerides markedly increased in the liver, while those in serum decreased. Electron microscopic examination of hepatocytes revealed numerous secretory vesicles filled with nascent VLDL. In hexestrol‐treated animals, the colchicine treatment was associated with marked decreases in serumesterified cholesterol and triglyceride as seen in the controls. However, there were no further increases of esterified cholesterol in the liver, and the increase of triglycerides was slight. Electron microscopic examination showed less secretory droplets than in the controls.

These data suggest that very low density lipoproteins (VLDL) synthesis in the liver of hexestrol treated rats was inhibited. An accumulation of esterified cholesterol with a marked decrease in serum could not be accounted for by the inhibition of lipoproteins secretion, but rather by their enhanced entry into the liver.
The thiobarbituric acid test for lipid peroxidation: Structure of the adduct with malondialdehyde
Authors: Nair Vasu , Turner Gregory A.
Published: November 2006

The complete structure of the red crystalline 2∶1 adduct from thiobarbituric acid and malondialdehyde has been unambiguously determined by FTIR and high‐field1H and13C NMR studies.