bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxidation of 1‐O‐(alk‐1‐enyl)‐2,3‐di‐O‐acylglycerols: Models for plasmalogen oxidation
Authors: Foglia Thomas A. , Nungesser Edwin , Marmer William N.
Published: November 2006

Alk‐1‐enyl diacyl glycerides, model compounds for plasmalogen lipids, were synthesized for use as substrates in oxidation studies. The neutral plasmalogen glycerides prepared included 1‐O‐(hexadec‐1‐enyl)‐2,3‐di‐O‐stearoylglycerol (4a) and 1‐O‐(hexadec‐1‐enyl)‐2‐O‐linoleoyl‐3‐O‐stearoylglycerol (4b). Oxidative disappearance of these glycerides was followed directly by high performance liquid chromatography (HPLC). The extent of oxidation of the side chains of these glycerides, i.e. the alkenyl ether and fatty acyl functions, was monitored by conversion of the side chains to dimethylacetal and methyl ester by methanolysis, followed by subsequent gas chromatography (GC) of the methanolysis products. Both analytical approaches show that the alkenyl ether function of neat4a oxidizes more slowly than neat ethyl linoleate. However, the rate of alkenyl ether loss from4a is accelerated in the presence of added ethyl linoleate. Moreover, when the linoleoyl group is incorporated into the 2‐position of the alkenyl glyceride, as in4b, the rate of loss of the alkenyl group was shown to be similar to the rate of loss of the linoleoyl group. These results suggest that oxidation of plasmalogen glycerides should not be ignored as a factor that contributes to the oxidative instability of animal tissue.
Nanogram quantification of nonpolar lipid classes in environmental samples by high performance thin layer chromatography
Authors: Conte Maureen H. , Bishop James K. B.
Published: November 2006

A sensitive, simple, and rapid high performance thin layer chromatography (HPTLC) method that quantifies nanogram amounts of complex nonpolar lipid classes in environmental samples with a minimum of sample preparation is presented. The derivatization method is lipid‐specific and insensitive to carbon number or the degree of unsaturation of the fatty acids composing the lipid class compounds. Nonpolar lipid classes ranging from 10 to over 500 ng easily may be quantified in the same sample run. The coefficient of variation for sample replicates on different plates ranged from 2.3% to 5.9%. Accuracy of the method is better than 15%. The nonpolar lipid class composition of <53 μm oceanic particles in a vertical depth profile of the upper 600 meters of the Slope Water was determined to illustrate the HPTLC method. The observed changes in particulate lipid class composition indicate that secondary production by deep‐living organisms significantly alters suspended particle composition with depth in the water column.
The existence of a soluble plasmalogenase in guinea pig tissues
Authors: McMaster Christopher R. , Lu Can‐Qun , Choy Patrick C.
Published: November 2006

The distribution of plasmalogenase for the hydrolysis of 1‐alkenyl‐2‐acyl‐sn‐glycero‐3‐phosphoethanolamine (plasmenylethanolamine) in the subcellular fractions of guinea pig tissues was examined. Plasmalogenase activity was found in high abundance in the cytosolic fractions of the brain and the heart. Assessment of microsomal marker enzyme activities in the cytosolic fraction revealed that plasmalogenase activity in the cytosol was not due to microsomal contaminations. The characteristics of the cytosolic plasmalogenase were very similar to the microsomal enzyme with respect to the pH profile of the reaction, the presence of divalent cations and Km values for plasmenylethanolamine. However, the cytosolic enzyme was slightly less stable at 55°C than the microsomal enzyme. Cytosolic enzyme activity was eluted as a broad peak in Sepharose 6B chromatography with an average molecular weight of 250,000. Our results demonstrate that most of brain plasmalogenase activity is soluble which makes the brain cytosol an excellent source to initiate the purification of this enzyme.
Kinetics of photoperoxidation of arachidonic acid: Molecular mechanisms and effects of antioxidants
Authors: Iliou Jean‐Pierre , Jourd'heuil David , Robin Frédéric , Serkiz Bernard , Guivarc'h Pascale , Volland Jean‐Paul , Vilaine Jean‐Paul
Published: November 2006

The kinetics of photoperoxidation of [1−14C]arachidonic acid (20∶4n−6) at 1.32 mM was studied either with the unsaturated fatty acid alone or in the presence of 10μM of antioxidants and/or inhibitors of eicosanoid metabolism. The photosensitizer used wasmeso‐tetraphenylporphine. The time‐course of the reactions was followed by ultraviolet spectral analysis, thiobarbituric acid reactivity and high‐performance liquid chromatographic analysis of aliquots sampled every 15 min during the 4 h of irradiation. The kinetics of photoperoxidation of 20∶4n−6 can be divided into three main successive steps: (i) monohydroperoxidation, characterized by the appearance of conjugated diene patterns and monohydroperoxidized 20∶4n−6; (ii) secondary oxidation characterized by polyoxygenated products such as dihydroperoxidized 20∶4n−6 possessing conjugated triene patterns; and (iii) the disappearance of conjugated patterns and the oxidative cleavage of the products of the two first steps into aldehydic molecules reacting with thiobarbituric acid. During the first 90 min of irradiation, the mechanism of monohydroperoxidation (step one) is purely or predominantly type II photoperoxidation involving only singlet oxygen. This step was inhibited by β‐carotene and by BW755C (3‐amino‐1‐[3‐trifluoromethylphenyl]2‐pyrazoline). In contrast, the reactions involved in the second and third steps were predominantly type I photoperoxidation involving radical mechanisms. These latter steps were inhibited by β‐carotene, BW755C, vitamin E and probucol. Indomethacin and 5,8,11,14‐eicosatetraynoic acid did not alter 20∶4n−6 photoperoxidation. Thisin vitro model of lipid photoperoxidation allows the screening of antioxidants in accordance with their singlet oxygen quenching and/or free radical scavenging properties.
Increased globotriaosylceramide in familial dysautonomia
Authors: Strasberg Paula , Yeger Herman , Warren Irene
Published: November 2006

Familial Dysautonomia (FD) is an autosomal recessive disease of unknown etiology, occurring primarily in Ashkenazi Jews. Patients are neurologically impaired, with deficits primarily in autonomic and sensory functions. The biochemical and genetic defects have remained elusive, precluding carrier detection and prenatal diagnosis. High‐performance liquid chromatography data indicated up to a threefold increase in the neutral glycosphingolipid globotriaosylceramide in Dysautonomic fibroblasts and lymphoblasts. Total ganglioside values, measured by colorimetric, fluorometric or specific sodium borohydride incorporation, were decreased. Affected fibroblasts exhibited a range of pleomorphic phenotypes, such that the usual swirl‐like confluent growth pattern of normal fibroblasts was distorted to varying degrees, suggesting abnormalities in the FD plasma membrane, possibly affecting cell‐cell contacts. The glycosphingolipid increase could not be accounted for on the basis of markedly decreased α‐galactosidase activity, as in Fabry's disease, where patients also display decreased autonomic function.
Prolonged retention of doubly labeled phosphatidylcholine in human plasma and erythrocytes after oral administration
Authors: Galli Claudio , Sirtori Cesare R. , Mosconi Cristina , Medini Lucia , Gianfranceschi Gemma , Vaccarino Viola , Scolastico Carlo
Published: November 2006

The plasma kinetics of a preparation of dilinoleoyl phosphatidylcholine (DLPC) specifically labeled with3H in the choline moiety and with14C in the 2‐fatty acid (FA) were evaluated in six healthy volunteers after oral administration. Retention of both isotopes in plasma exceeded expectations, with a half‐life in the elimination phase of 172.2 h for3H and 69.7 h for14C. Up to 60 d after administration, there were still significant levels of radioactivity present in plasma. The relative stability of the [14C]FA label was demonstrated by the retention for more than 12 h of an isotope ratio close to that of the compound administered. The14C label of DLPC remained in position‐2, as assessed by cleavage of plasma phospholipids with phospholipase A2. The [3H]choline label showed an early incorporation into high density lipoproteins and subsequently into low density lipoproteins (LDL); conversely, the14C radioactivity was rapidly incorporated into triacylglycerols that were mainly associated with very low density lipoproteins. Radioactivity measurements revealed that both isotopes remained the longest time in LDL. In red blood cell (RBC) lipids, [3H]choline radioactivity accumulated over time, with a plateau after 48 h, whereas FA radioactivity accumulated more rapidly and was followed by a progressive decay. Analysis of the isotope ratio in these cells suggested an early incorporation of lyso products followed by rapid transfer of FA from plasma. The RBC maintained considerable radioactivity for a prolonged time, thus acting as a possible reservoir for the DLPC administered. Our study showed that dilinoleoyl PC remained in plasma longer than predicted based on earlier studies, and that after absorption the FA label was found in position 2.
Nonessential fatty acids in formula fat blends influence essential fatty acid metabolism and composition in plasma and organ lipid classes in piglets
Authors: Wall Katharine M. , Diersen‐Schade Deborah , Innis Sheila M.
Published: November 2006

The n‐6 and n‐3 fatty acid status of developing organs is the cumulative result of the diet lipid composition and many complex events of lipid metabolism. Little information is available, however, on the potential effects of the saturated fatty acid chain length (8:0–16:0) or oleic acid (18:1) content of the diet on the subsequent metabolism of the essential fatty acids 18:2n‐6 and 18:3n‐3 and their elongated/desaturated products. The effects of feeding piglets formulas with fat blends containing either coconut oil (12:0±14:0) or medium chain triglycerides (MCT, 8:0±10:0) but similar levels of 18:1, 18:2n‐6 and 18:3n‐3, or MCT with high or low 18:1 but constant 18:2n‐6 and 18:3n‐3 on the fatty acid composition of plasma, liver and kidney triglycerides, phospholipids and cholesteryl esters, and of brain total lipid, were studied. Diet‐induced changes in the fatty acid composition of lipid classes were generally similar for plasma, liver and kidney. Dietary 18:1 content was reflected in tissue lipids and was inversely associated with levels of 18:2n‐6. Lower percentage of 18:2n‐6, however, was not associated with lower levels of its elongated/desaturated product 20:4n‐6 but was associated with higher levels of 22:6n‐3. Feeding coconut oilvs. MCT resulted in lower 18:1 levels in all lipids, and higher percentages of 20:4n‐6 in tissue phospholipid. Increasing the dietary n‐6/n‐3 ratio from 5 to 8 significantly increased tissue percentage of 18:2n‐6 and decreased phospholipid 22:6n‐3. In contrast to plasma, liver and kidney, brain lipid fatty acid composition was not influenced by the formula saturated fatty acid chain length, content of 18:1, or n‐6/n‐3 ratio. In summary, the studies show that the dietary requirement for n‐6 and n‐3 fatty acids may be influenced by the nonessential saturated and monounsaturated fatty acids fed concurrently.
Formation of a thiamine disulfide complex with fatty acid: Mechanism of formation of the complex
Authors: Komata Yasuko , Fujie Tadao , Kaneko Akiko , Ueda Fumio , Urano Shiro
Published: November 2006

The formation of complexes between thiamine disulfide (TDS) orO‐acetyl thiamine disulfide (O‐acetyl TDS) and fatty acid or fatty acid methyl ester in methanol has been studied by fluorescence quenching and13C NMR relaxation (T1) measurements. The association constants (K‐values) of TDS andO‐acetyl TDS with fatty acids (from 11∶0 to 18∶0, and 18∶1, 18∶2, 18∶3 and 20∶4) and fatty acid methyl esters have been determined. These values do not depend on either the number of carbon atoms or the degree of unsaturation of the fatty acid. The K‐values of TDS andO‐acetyl TDS with fatty acid were 7.8 M−1 and 5.1 M−1, respectively. The K‐values of TDS andO‐acetyl TDS with fatty acid methyl ester were very small. These results show that the‐OH moiety in TDS and the‐COOH moiety in the fatty acid are necessary for formation of the complex
Purification and characterization of fatty acid‐binding protein from human placenta
Authors: Das Tanya , Sa Gourisankar , Mukherjea Manju
Published: November 2006

Purification of a cytosolic fatty acid‐binding protein (FABP) from developing human placenta has been achieved, and its role in modulating the inhibition of human placental glucose‐6‐phosphate dehydrogenase (G6PD) by palmitoyl‐CoA (PAL‐CoA) has been studied. FABP was resolved into three peaks, viz. DE‐I, DE‐II and DE‐III, by DEAE cellulose chromatography. DE‐I was almost lipid‐free. Presence of endogenous fatty acids in DE‐II and DE‐III was detected by thin layer chromatography (TLC). Fatty acids were the only detectable lipid component in these fractions. Gas liquid chromatography (GLC) analysis revealed that DE‐II binds long chain saturated and unsaturated fatty acids nonspecifically, whereas DE‐III is mainly an arachidonic acid carrier. Each of these fractions, viz. DE‐I, DE‐II and DE‐III, has a molecular weight of 14,200 Daltons. Ouchterlony double immunodiffusion studies have confirmed the immunochemical identity of these three fractions of placental FABP. Separation in ion exchanger may be due to their different isoelectric points and varied types of binding affinities. Human placental G6PD was inhibited 50% by 0.03 mM PAL‐CoA. The DE‐II fraction of FABP enhanced the activity of G6PD in the absence of added PAL‐CoA and protected against PAL‐CoA inhibition of the enzyme. Such a modulating effect of FABP in this inhibition is attributable to binding of long chain acyl‐CoA rather than to a direct effect of FABP on the enzyme itself.
Isolation and chemical composition of surface‐active material from human lung lavage
Authors: Sadana T. , Dhall K. , Sanyal S. N. , Wali A. , Minocha R. , Majumdar S.
Published: November 2006

Surface‐active material (SF) was isolated from human lung lavage fluid collected at autopsy employing differential and sucrose density gradient centrifugation. The isolated material showed well‐defined electron microscopic structure, consisting of clearly preserved, closely packed vesicles with limiting membranes and inclusion bodies. It showed a very high degree of alkaline phosphatase specific activity and was devoid of other subcellular contaminants. The isolated material also showed a high phospholipid/protein ratio and increasing surface activity when monitored at different stages of purification. It contained 68.5% phosphatidylcholine, 11.5% phosphatidylglycerol and relatively smaller amounts of phosphatidylethanolamine and other individual phospholipid (PL) classes. In addition, cholesterol, unesterified fatty acids, triacylglycerols and other neutral lipids were found. Saturated fatty acids, particularly palmitic acid (16∶0), predominated in the major PL fractions. However, various fatty acids of which oleic acid (18∶1) constituted a large proportion also are present. Chemical analysis of the material showed that besides lipids and proteins, nucleic acids, sialic acid, hexose, amino sugars, nitrogen and phosphorus were present. The delipidated material showed the presence of three to four proteins as characterized by sodium dodecylsulfate (SDS)‐polyacrylamide gel electrophoresis, and gel permeation chromatography on Sephadex G‐200 resolved two well‐separated peaks. The first fraction contained serum‐associated 68 kDa protein, while the second fraction had two apoproteins with molecular weights of 34 kDa and 10 kDa. These two proteins were associated with the SF and they, as well as the whole surface‐active material, strongly reacted with the antibody directed against the whole SF in a double‐diffusion immunoprecipitation assay. The first Sephadex fraction containing a 68 kDa protein did not produce any precipitation line when reacted against antisera.
Promotion of iron‐induced rat liver microsomal lipid peroxidation by copper
Authors: Beckman Jeffrey K. , Borowitz Stephen M. , Greene Harry L. , Burr Ian M.
Published: November 2006

Although copper has been demonstrated to promote lipid peroxidation in a number of systems, the mechanisms involved have not been fully defined. In this study, the role of copper in modifying lipid peroxidation has been explored in rat hepatic microsomes. In an in vitro system containing reduced glutathione (GSH, 200 μM) and Tris buffer, pH 7,4, cupric sulfate (1–50 μM) potentiated lipid peroxidation induced by ferrous sulfate (10 μM) but was unable to elicit peroxidation in the absence of iron. Higher levels of cupric sulfate (100 μM or greater) were inhibitory. The nature as well as the extent of the peroxidative response of microsomes to cupric sulfate were dependent on glutathione levels in addition to those of iron. Cupric sulfate (100 μM) strongly potentiated ferrous ion‐induced lipid peroxidation in the presence of 400–800 μM GSH, while it inhibited peroxidation at lower levels of GSH (0–200 μM) and did not affect ferrous ion‐induced peroxidation with glutathione levels of 3–10 mM.

The potentiating effect of copper on ferrous ion‐induced lipid peroxidation was further explored by investigating: (1) potential GSH‐mediated reduction of cupric ions; (2) potential copper/GSH‐mediated reduction of ferric ions (formed by oxidation during incubation); and (3) possible promotion of propagation reactions by copper/GSH. Our results indicate that cupric ions are reduced by GSH and thus are converted from an inhibitor to an enhancer of iron‐induced lipid peroxidation. Cuprous ions appear to potentiate lipid peroxidation by reduction of ferric ions, rather than by promoting propagation reactions. Iron (in a specific Fe+2/Fe+3 ratio) is then an effective promoter of initiation reactions.
Serum lipids in spontaneously hypertensive rats and sprague‐dawley rats fed menhaden oil
Authors: Kingsley T. R. , Snyder D. L.
Published: November 2006

Dietary n‐3 fatty acids, abundant in fish oil, exert a variety of effects that attenuate cardiovascular disease. In this study, we assessed the effect of fish oil (menhaden oil) on the serum lipid profile in hypertensive and normotensive rats. Spontaneously hypertensive rats (SHR) or Sprague‐Dawley rats (SD) were fed either standard powdered diet (L‐485), or L‐485+5% menhaden oil (MO) or L‐485+5% corn oil (CO) from weaning through eight months of age. Systolic blood pressure (BP) was periodically determined on SHR. Serum lipid profiles were performed at eight months on sample taken from the exposed hearts of anesthetized, fasted rats. SHR, compared with SD (diets combined) had significantly lower triaclyglycerols (TG), higher cholesterol (CHOL), higher high density lipoprotein cholesterol (HDL CHOL), higher low density lipoprotein cholesterol (LDL CHOL), and a higher LDL:HDL ratio. Comparison among diets (strains combined) revealed that rats fed MO had the lowest values for TG, CHOL, LDL and LDL:HDL; HDL did no vary with diet. SHR were less responsive to diet‐induced changes than were SD; no decrease in TG, LDL or LDL:HDL was observed in SHR, nor was degree of hypertension altered in SHR by the MO or CO diet. In summary, MO is more effective than CO in shifting the lipid profile of rats toward one that is less atherogenic. However, the SD rat is more susceptible to diet‐induced lipid modification than is the SHR.
Composition and physical state of phospholipids in calanoid copepods from India and Norway
Authors: Farkas T. , Storebakken T. , Bhosle N. B.
Published: November 2006

The fatty acid composition and physical state of isolated phospholipids obtained from marine copepods collected on the Southwest coast of India (Calanus ssp.) and the West coast of Norway (Calanus finmarchicus) were investigated to compare the adaptation of membrane lipids with seawater temperatures. Phospholipid vesicles obtained from the tropic copepods proved more rigid than those fromC. finmarchicus, as assessed by diphenylhexatriene fluorescence polarization techniques. In each case, there were two breaks present on the fluorescence polarization vs 1/T plots, suggesting that the onset and completion of phase separation to occurred above 0 C. For the tropic copepods, the onset of phase separation roughly corresponded to the ambient water temperature, while forC. finmarchicus some discrepancies were observed, depending on the time of the year. Phospholipids in copepods from both habitats contained more than 50% unsaturated fatty acids, the animals from Norway containing slightly higher amounts. The data indicate an adaptation of membranes to temperature.
Enhanced survival to endotoxin in guinea pigs fed IV fish oil emulsion
Authors: Mascioli Edward , Leader Lorraine , Flores Enrique , Trimbo Susan , Bistrian Bruce , Blackburn George
Published: November 2006

Improved survival to endotoxin has been demonstrated in rats pretreated with cyclooxygenase inhibitors or made essential fatty acid deficient, implying that excessive ω6 fatty acids, possibly through their eicosanoid products, contribute to mortality. Following endotoxin administration, we also have shown improvement in survival with oral diets supplemented with fish oil. This study sought to explore whether parenteral fish oil ameliorates the adverse impact of endotoxin.

Male Hartley‐strain guinea pigs were obtained at a body weight of 500 g and fed a normal laboratory diet. Central venous lines through which the animals received either a 10% safflower oil emulsion (n=11) or a 10% fish oil emulsion (n=11) during two, 24‐hr periods separated by two days were inserted. Two days after the second infusion, endotoxin (0.35 mg/100 g b.w.), was given intraperitoneally, and survival was noted. The animals received a total of 25.4 g of IV fat per kg b.w., including 5.3 g of eicosapentaenoic acid per kg b.w., for the fish oil group.

From six hr after endotoxin through four days, there was better survival in the fish oil group (p<.006). Final mortality showed 7/11 fish‐fed vs 2/11 safflower‐fed animals surviving. We conclude that the administration of parenteral fish oil, even for a brief time, can have a profound effect on subsequent survival to endotoxin.
Evidence for loss of tritium from 3β‐tritiated deoxycholic acid during enterohepatic cycling in man
Authors: Marcus S. N. , Heaton K. W.
Published: November 2006

A double‐label single‐intubation isotope technique was assessed for studying deoxycholic acid metabolism by simultaneous IV administration of [3β‐3H]deoxycholic acid and [24‐14C]deoxycholic acid to five healthy subjects. The3H/14C ratio in duodenal bile fell progressively in all subjects, the mean reduction on day four being 48.8%. When the same labeled bile acids were administered to three ileostomy subjects, again the ratio fell with a mean reduction of 44.4% on day four. This fall more likely was due to hepatic exchange of tritium for hydrogen, rather than to colonic bacterial oxidation. [3β‐3H]Deoxycholic acid should not be used to study the kinetics and metabolism of deoxycholic acid.
BW755C or staurosporine inhibits collagen‐stimulated phosphoinositide phosphorylation in platelets
Authors: Thomas Lisa M. , Holub Bruce J.
Published: November 2006

Stimulation of platelets by collagen results in increased formation of the polyphosphoinositides, phosphatidylinositol phosphate (PtdInsP) and phosphatidylinositol bisphosphate (PtdInsP2) through stimulation of phosphoinositide kinase activities. We investigated a possible regulatory role of endogenous thromboxane formation and protein kinase C (PKC) activation in the induction of phosphoinositide phosphorylation following collagen stimulation, as well as following stimulation by the thromboxane mimetic, U‐46619. Human platelets were prelabeled with [3H]inositol and stimulated with collagen (2 μg/mL) or U‐46619 (1 μM), in the absence or presence of either the cyclo‐oxygenase/lipoxygenase inhibitor, BW755C, or staurosporine, a putative inhibitor or PKC. Collagen stimulation resulted in a time‐dependent increase in [3Hinositol‐labeled PtdInsP and PtdInsP2 which was completely inhibited in the presence of BW755C. Addition of U‐46619 to BW755C‐treated, collagen‐stimulated platelets restored the increased polyphosphoinositide formation. Stimulation of platelets with U‐46619 alone also resulted in increased formation of [3H]PtdInsP and [3H]PtdInsP2, but this was not affected by the presence of BW755C. These results suggest that the collagen‐induced activation of phosphoinositide kinases was dependent upon thromboxane formation, but that U‐46619‐induced phosphoinositide formation was rather independent of further thromboxane production. Pretreatment of platelets with staurosporine, prior to agonist addition, completely blocked the collagen‐stimulated rise in radiolabeled PtdInsP and the U‐46619‐induced PtdInsP and PtdInsP2 generations, suggesting that protein kinase, possibly PKC, may play a role in the activation of phosphoinositide kinases by these agonists.
Decrease in platelet reduced glutathione increases lipoxygenase activity and decreases vitamin E
Authors: Calzada Catherine , Véricel Evelyne , Lagarde Michel
Published: November 2006

Unstimulated normal human blood platelets were treated with azodicarboxylic acidbis(dimethylamide) (diamide), a thiol‐oxidizing agent. Oxygenated arachidonic acid (AA) metabolites, malondialdehyde (MDA), and tocopherols were then quantified by high‐performance liquid chromatography (HPLC). Diamide treatment partially decreased the amount of reduced glutathione (GSH) content and induced a subsequent decrease in peroxidase activity. However, formation of 12‐hydroxy‐eicosatetraenoic acid (12‐HETE), the end‐product of lipoxygenation of AA, increased. Formation of MDA, a marker of overall lipid peroxidation, was also enhanced. Furthermore, platelet α‐tocopherol, but not γ‐tocopherol, significantly decreased. These results indicate that enhanced “basal” lipoxygenase activity, as a marker of specific AA oxygenation, may be linked to decreased platelet antioxidant status.
Modulation of polyunsaturated fatty acid content of triglycerides in rat pre‐adipocytes in culture
Authors: Gavino Grace R. , Gavino Victor C.
Published: November 2006

Rat peri‐renal and epididymal pre‐adipocytes in culture undergoing triglyceride (TG) accumulation were incubated with oleic (18∶1), linoleic (18∶2), α‐linolenic (18∶3ω3), arachidonic (20∶4) and 4,7,10,13,16,19‐docasahexaenoic (22∶6ω3) acids in the presence of 0.8 μM insulin. The fatty acids were incorporated in cellular TG with relative enrichments over control from 1.4‐fold for 18∶1 to greater than 40‐fold for 18∶3ω3. Greater than 80% of fatty acids taken up were incorporated into cellular TG. The balance was distributed, in decreasing amounts, into phospholipids, unidentified intracellular constituents, and ketone bodies. The P/S ratio of cellular TG was at least an order of magnitude lower than that of the external milieu for both cell types and for all treatment groups, including controls. Doubling the concentration of treatment fatty acid increased its incorporation into cellular TG. However, it did not affect the accumulation of the other fatty acids in TG. Epididymal cells consistently acquire a higher proportion of treatment fatty acids in cell TG than peri‐renal cells. Pre‐adipocytes with polyunsaturated fatty acids (PUFA)‐enriched TG is a potential model for the study of PUFA metabolism in these types of cells
trans fatty acids. 4. Effects on fatty acid composition of colostrum and milk
Authors: Pettersen Jan , Opstvedt Johannes
Published: November 2006

trans Isometric fatty acids of partially hydrogenated fish oil (PHFO) consist oftrans 20∶1 andtrans 22∶1 in addition to thetrans isomers of 18∶1, which are abundant in hydrogenated vegetable oils, such as in partially hydrogenated soybean oil (PHSBO). The effects of dietarytrans fatty acids in PHFO and PHSBO on the fatty acid composition of milk were studied at 0 (colostrum) and 21 dayspostpartum in sows. The dietary fats were PHFO (28%trans), or PHSBO (36%trans) and lard. Sunflower seed oil (4%) was added to each diet. The fats were fed from three weeks of age throughout the lactation period of Experiment 1. In Experiment 2 PHFO or “fully” hydrogenated fish oil (HFO) (19%trans), in comparison with coconut oil (CF) (0%trans), was fed with two levels of dietary linoleic acid, 1 and 2.7% from conception throughout the lactation period. Feedingtrans‐containing fats led to secretion oftrans fatty acids in the milk lipids. Levels oftrans 18∶1 andtrans 20∶1 in milk lipids, as percentages of totalcis+trans 18∶1 andcis+trans 20∶1, respectively, were about 60% of that of the dietary fats, with no significant differences between PHFO and PHSBO. The levels were similar for colostrum and milk. Feeding HFO gave relatively lesstrans 18∶1 andtrans 20∶1 fatty acids in milk lipids than did PHFO and PHSBO. Only low levels ofcis+trans 22∶1 were found in milk lipids. Feedingtrans‐containing fat had no consistent effects on the level of polyenoic fatty acids but reduced the level of saturated fatty acids and increased the level ofcis+trans monoenoic fatty acids. Increasing the dietary level of linoleic acid had no effect on the secretion oftrans fatty acids but increased the level of linoleic acid in milk. The overall conclusion was that the effect of dietary fats containingtrans fatty acids on the fat content and the fatty acid composition of colostrum and milk in sows were moderate to minor.
Distribution among tissues of intravenously administered sucrose octaoleate
Authors: Mattson F. H. , Jandacek R. J.
Published: November 2006

The distribution of [14C]oleate label in rat tissues in the 6 hr after intravenous administration of sucrose octa‐[14C]oleate (7.5 mg; SuO8) was compared with that observed after administration of [14C]triolein. The [14C]‐oleate label, whether injected as triolein emulsion, or as chylomicrons obtained from donor animals, rapidly cleared from the serum; only 10% or less remained in the serum 15 min after injection. Labeled SuO8 disappeared less rapidly from the serum; about one‐third of the dose was present after 15 min, and after 120 min 14% remained. In the liver, there was an initial greater accumulation of fatty acid label when and emulsion of either triolein or SuO8 was given rather than the chylomicrons. The octaester continued to accumulate in the liver throughout the 6 hr of study, and 78% of the initial dose was present at that time. By contrast, although one‐third of the triolein, as of SuO8, was found in the liver shortly after injection, levels subsequently decreased; at 6 hr, 12% of the label remained associated with that organ. A small portion, up to 8% of the acid label, whether administered as chylomicrons or as a triolein emulsion, was found in the epididymal fat pads. Smaller amounts, usually 1% or less, of the [14C]oleate label were found in fat pads following the injection of labeled SuO8. In a separate study, the levels of acid label in the liver and spleen were monitored for 21 days following the intravenous administration of [14C]SuO8. There was an initial accumulation of approximately half of the injected lipid label in the liver and one‐quarter in the spleen. By day 21, the level in the liver had decreased to one‐third of that administered, while the level in spleen remained at one‐quarter.
The excretion and characterization of intravenously administered olestra
Authors: Jandacek R. J. , Holcombe B. N.
Published: November 2006

Although sucrose octaoleate that is consumed is neither digested or absorbed, following intravenous injection it is found mainly in the liver. Olestra is a mixture of the hexa‐, hepta‐, and octaesters of sucrose. To follow the metabolic fate of intravenously administered [14C]sucrose‐labeled olestra, we measured its urinary elimination, and the rate of excretion of14C in the feces, and characterized the14C‐labeled material that appeared in bile. The fecal excretion for days 4–14 after dosing was found to be first order with the half‐life of the injected olestra being 5.0±0.5 days. The14C recovered in the bile was soluble in chloroform. Two‐dimensional thin‐layer chromatography autoradiograms of the biliary lipid showed the pattern of the biliary14C to be essentially the same as that of the dosed olestra. Biliary excretion and subsequent fecal egestion of essentially unhydrolyzed sucrose esters is the principal route for the removal of intravenously administered olestra. Only traces of14C were found in the urine.
Interaction between dietary proteins and lipids in the regulation of serum and liver lipids in the rabbit. Effect of fish protein
Authors: Bergeron N. , Deshaies Y. , Lavigne C. , Jacques H.
Published: November 2006

Purified diets varying in dietary protein, namely casein (CA), soy protein (SP), fish protein (FP), and lipid origin (corn oil (CN), coconut oil (CO)) were fed to rabbits to evaluate the effects of protein and fat source, as well as protein‐lipid interactions, on serum total, lipoprotein and hepatic lipid levels. Dietary proteins and lipids exerted a separate effect on serum total cholesterol (C), very low‐density lipoprotein cholesterol (VLDL‐C), and low‐density lipoprotein cholesterol to high density lipoprotein cholesterol (LDL‐C/HDL‐C) ratio. Hence, CA increased serum cholesterol compared to SP, while coconut oil enhanced serum and VLDL‐C, and decreased LDL‐C/HDL‐C compared to corn oil. Dietary proteins interacted with dietary lipids to modulate HDL‐C levels. Thus, FP maintained a high level of HDL‐C regardless of lipid origin, compared to CA and SP whose HDL‐C levels were decreased by corn oil, compared to coconut oil. A dietary protein‐lipid interaction was also observed in the regulation of liver cholesterol levels. Coconut oil, compared to corn oil, decreased liver cholesterol in rabbits fed FP, whereas hepatic cholesterol concentration was unaltered by dietary lipid source in CA‐ and SP‐fed rabbits. These results demonstrate that dietary proteins act synergistically with dietary lipids to regulate cholesterol metabolism in the rabbit.
A simple assay for lipid hydroperoxides based on triphenylphosphine oxidation and high‐performance liquid chromatography
Authors: Nakamura Takashi , Maeda Hiroyuki
Published: November 2006

A simple and sensitive method was developed to measure total hydroperoxides. After the reduction of hydroperoxides with triphenylphosphine (TP) in cyclohexane at 30°C, the amount of triphenylphosphine oxide (TPO) produced is determined by reverse‐phase or normal‐phase high‐performance liquid chromatography (HPLC) in combination with an ultraviolet (UV)‐detector by measuring absorption at 220 or 260 nm. TPO was shown to be gener‐ated stoichiometrically by reduction of known amounts of either cumene hydroperoxide or methyl 13‐hydroper‐oxyoctadecadienoate. For various lipids at low levels of oxidation, the peroxide values determined by this method were in good agreement with those obtained by conventional iodometry. The detection limit of TPO in HPLC using absorption at 220 nm was less than 10 pmol. Consequently, total hydroperoxides in lipids at levels corresponding to less than a peroxide value of 1 can be estimated by the TP method on a 10‐mg sample.
The effects of tricaine methanesulfonate (MS‐222) on plasma nonesterified fatty acids in rainbow trout,Oncorhynchus mykiss
Authors: Harrington A. J. , Russell K. A. , Singer T. D. , Ballantyne J. S.
Published: November 2006

The effects of tricaine methanesulfonate (MS‐222), a commonly used fish anesthetic, on plasma nonesterified fatty acid levels (NEFA) were examined in rainbow trout,Oncorhynchus mykiss. Total NEFA levels declined with increasing duration of exposure to MS‐222. Most of the decline in total NEFA was due to decreases in saturated fatty acids (14∶0, 16∶0 and 18∶0). The fatty acid displaying the most rapid response to exposure to MS‐222 was 20∶5n−3. The lower plasma NEFA levels in anesthetized fish may be explained by depressed lipolysis in the presence of the anesthetic.
Mass spectra of fatty acid derivatives, of isopropylidenes of novel glyceryl ethers of cod muscle and of phenolic acetates obtained with the finnigan mat ion trap detector
Authors: Ratnayake W. M. N. , Timmins A. , Ohshima T. , Ackman R. G.
Published: November 2006

The applicability of the Finnigan MAT Ion Trap Detector (ITD) mass spectrometer for structure determination in some selected fatty acids and their derivatives has been investigated. Isopropylidene derivatives of novel glyceryl ethers isolated from cod flesh and of phenolic acetates are included to indicate the potential for diverse structures and to clarify the protonation of ions. The ITD is a simple and unsophisticated gas liquid chromatographmass spectrometer, but the spectra obtained are in most respects comparable to those from more conventional electron impact mass spectrometers. However, due to the comparatively high background pressure (∼10−3 torr) in the ionization chamber of the ITD, there is a tendency for both neutral and ionized molecules to acquire protons from other molecules or fragments through collision. In many cases, the molecular ion was observed as the protonated molecular ion (M+1), as in chemical ionization mass spectrometry. These interactions can be minimized if the sample load is decreased. Phenolic acetates exhibit not only protonation of the molecular ion, but also protonation of stable fragmented neutralmolecules or ions.
Effects of dietary palm oil on arterial thrombosis, platelet responses and platelet membrane fluidity in rats
Authors: Rand Margaret L. , Hennissen Adje A. H. M. , Hornstra Gerard
Published: November 2006

Wistar rats were fed a control diet containing 5 energy % (en %) sunflowerseed oil or diets containing 50 en % of either palm oil, rich in saturated fatty acids, or sunflowerseed oil, high in linoleic acid, for at least eight weeks. Arterial thrombosis tendency, measured by the aorta loop technique, tended to be lowered by the palm oil diet and was lowered significantly by the sunflowerseed oil diet, compared with the control. Aggregation of platelets in whole blood activated with collagen was not altered by palm oil feeding, but was enhanced in the sunflowerseed oil group, compared with the control. The concomitant formation of thromboxane A2 was decreased by palm oil feeding, although formation of prostacyclin did not change; the ratio of thromboxane/prostacyclin formed was decreased significantly in the palm oil group. Compared with the control diet, platelet membrane fluidity, measured by fluorescence polarization, was not altered in the palm oil group and was significantly increased only by sunflowerseed‐oil feeding. Thus, although palm oil contains about 50% saturated fatty acids, it did not increase arterial thrombosis tendency and tended to decrease platelet aggregation, as compared with highly polyunsaturated sunflowerseed oil.
Investigations of the origin of the furan fatty acids (F‐acids)
Authors: Gorst‐Allman Charles P. , Puchta Volker , Spiteller G.
Published: November 2006

The possible role of linoleic acid as a biogenetic precursor of the furan fatty acids (F‐acids) was investigated in in vivo experiments in the rat, using a C19 analogue of linoleic acid and gas chromatography‐mass spectrometry. No evidence of incorporation of this compound into the F‐acids was found. Using an improved analysis procedure by converting F‐acids into their tetrahydrofuran derivatives (enabling a separation from the large amounts of normal fatty acids), F‐acids (F3, F4 and F6) were detected in rat food, correcting earlier results.

Quantification of F‐acid intake with food and excretion of furandicarboxylic acids in the urine, suggested the possibility that the F‐acids are not produced de novo in the rat, but instead accumulate in tissue after nutritional intake.
Effect of diethyl ether on phosphatidylcholine biosynthesis in hamster organs
Authors: O Karmin , Hatch Grant M. , Choy Patrick C.
Published: November 2006

The effect of diethyl ether anesthesia on phosphatidylcholine biosynthesis in hamster organs was investigated. Ether administration did not affect the incorporation of radioactive choline into phosphatidylcholine in the liver, heart, lung, brain and spleen. A significant (29%) decrease in the labeling of phosphatidylcholine was detected in the kidney of ether‐treated hamsters. Reduction in phosphatidylcholine labeling was not due to a diminished radioactive choline uptake but a decrease in the conversion of phosphocholine to CDP‐choline. The accumulation of labeled phosphocholine was caused by the translocation of CTP:phosphocholine cytidylyltransferase from microsomal (more‐active) form to cytosolic (less‐active) form. Ether administration appears to modulate the cytidylyltransferase in hamster kidney differently than that in other hamster organs.
Substituted fatty acids in the leaves of some higher plants
Authors: Hu Zi‐Ling , Mendoza Yery A. , Buchs Armand , Gülaçar Fazil O.
Published: November 2006

Substituted (hydroxy‐, epoxy‐ and dicarboxy) fatty acids have been analyzed in the needles of two gymnosperms (Pinus sylvestris andJuniperus communis) and the leaves of four angiosperms (Betula verrucosa, Populus nigra, Quercus petraea andCorylus avellana) growing in the Lake Léman basin. The differences in the distributions of the acids that have been analyzed are greater between the various species than between the spring and autumn samples of a given species. Moreover, the isomeric composition of the 8,16‐, 9,16‐ and 10,16‐dihy‐droxypalmitic acid mixture is specific for each species.
Milk fat globules: Fatty acid composition, size and in vivo regulation of fat liquidity
Authors: Timmen Hermann , Patton Stuart
Published: November 2006

Populations of large and small milk fat globules were isolated and analyzed to determine differences in fatty acid composition. Globule samples were obtained by centrifugation from milks of a herd and of individual animals produced under both pasture and barn feeding. Triacylglycerols of total globule lipids were prepared by thin layer chromatography and analyzed for fatty acid composition by gas chromatography. Using content of the acids in large globules as 100%, small globules contained fewer short‐chain acids, −5.9%, less stearic acid, −22.7%, and more oleic acids, +4.6%, mean values for five trials. These differences are consistent with alternative use of short‐chain acids or oleic acid converted from stearic acid to maintain liquidity at body temperature of milk fat globules and their precursors, intracellular lipid droplets. Stearyl‐CoA desaturase (EC 1.14.99.5), which maintains fluidity of cellular endoplasmic reticulum membrane, is suggested to play a key role in regulating globule fat liquidity. Possible origins of differences between individual globules in fatty acid composition of their triacylglycerols are discussed.
6‐methyl‐8‐hexadecenoic acid: A novel fatty acid from the marine spongeDesmapsama anchorata
Authors: Carballeira Néstor M. , Maldonado Maria E.
Published: November 2006

The novel fatty acid 7‐methyl‐8‐hexadecenoic (1) was identified in the marine spongeDesmapsama anchorata. Other interesting fatty acids identified were 14‐methyl‐8‐hexadecenoic (2), better known through its methyl ester as one of the components of the sex attractant of the female dermestid beetle, and the saturated fatty acid 3‐methylheptadecanoic (3), known to possess larvicidal activity. The main phospholipid fatty acids encountered inD. anchorata were palmitic (16∶0), behenic (22∶0) and 5,9‐hexacosadienoic acid (26∶2), which together accounted for 50% of the total phospholipid fatty acid mixture.
Rhizomucor miehei triglyceride lipase is synthesized as a precursor
Authors: Boel Esper , Huge‐Jensen Birgitte , Christensen Mogens , Thim Lars , Fiil Niels P.
Published: November 2006

ARhizomucor miehie cDNA library constructed inEscherichia coli was screened with synthetic oligonucleotides designed from knowledge of a partial amino acid sequence of the secreted triglyceride lipase (triacyl‐glycerol acylhydrolase EC 3.1.1.3) from this fungus. Lipase‐specific recombinants were isolated and their insert sequenced. Unlike characterized bacterial and mammalian triglyceride lipases, the fungal enzyme is synthesized as a precursor, including a 70 amino acid residue propeptide between the 24 amino acid residues of the signal peptide and the 269 residues of the mature enzyme. The precursor processing mechanism, which involves cleavage between a methionine and a serine residue, is unknown. By sequence comparison with other lipases, a serine residue involved in substrate binding was identified in the fungal lipase. The sequence around this residue is well‐conserved among characterized lipases. Conservation of an intron in an isolated cDNA recombinant and immunoprecipitation of in vitro synthesizedR. miehei translation products indicates that the expression of the lipase gene might involve inefficient mRNA splicing.
Effects of hyperoxia and diet on murine tissue levels of vitamin E and polyunsaturated fatty acids
Authors: Tangney C. C. , McCloskey K. M. , Aye P. L.
Published: November 2006

One hundred eighty‐six adult female mice were studied to examine the effect of manipulating dietary vitamin E and fractional inspired oxygen concentrations (FiO2) on tissue levels of vitamin E, total polyunsaturated fatty acids (TPUFA) and conjugated dienes (CD) as an index of lipid peroxidation. Animals were fed custom diets containing either 0, 50 or 150 ppm DL‐α‐tocopheryl acetate. Once plasma vitamin E levels of mice fell below 0.2 mg/dl (at week 19), all mice were placed in chambers containing either room air (FiO2≈0.21) or FiO2>0.95 for the next 72 hr. Dietary manipulation had a major impact on the levels of vitamin E in plasma, lung and perirenal adipose tissues (p<0.0001, p<0.0001 and p<0.005, respectively). Dietary vitamin E deprivation was associated with significant reductions in lung glutathione peroxidase (GPX) activities (p<0.05) and in plasma TPUFA levels (p<0.05). No significant effect attributable to either diet or FiO2 was observed for liver vitamin E, liver TPUFA or lung TPUFA levels, or for those of CD in any tissue examined. Adipose TPUFA levels were depressed in all dietary groups exposed to FiO2>0.95, when compared with those of groups exposed to room air. The high FiO2 exposures also were associated with marked reductions in lung to body weight ratios (p<0.01). These data suggest that dietary vitamin E treatment after long‐term feeding can modify vitamin levels in plasma, lung and adipose tissue, and lung GPX activities. Vitamin E levels in liver seemed less responsive to our dietary manipulations in adult female mice, though expressing liver vitamin E levels in terms of TPUFA revealed significant differences between the ratios from 0 and 150 ppm vitamin E groups (p<0.05).
Trans fatty acids. 1. Growth, fertility, organ weights and nerve histology and conduction velocity in sows and offspring
Authors: Opstvedt Johannes , Pettersen Jan , Mork Sverre J.
Published: November 2006

Effects of dietarytrans fatty acids on the pre‐ and postnatal growth and development in pigs were studied with special emphasis on nervous tissue. In experiment 1, female pigs were fed partially hydrogenated fish oil (PHFO) (28%trans) or soybean oil (PHSBO) (36%trans), in comparison with lard (0%trans) from weaning (3 wk) through the first reproduction cycle (up to 2 yr). In experiment 2, female pigs were fed two fish oils (33 and 19%trans) in comparison with coconut oil (0%trans) in diets with low and high levels of linoleic acid (18∶2n−6cis,cis) from gestation until their offspring were three wk old. Compared with thetrans‐free fats, thetrans‐containing fats had no effect on growth and development, feed consumption and utilization or on the weight of the brain, heart, kidneys, liver, lungs or spleen in the adult sows and their offspring. No effects from the experimental fats were found on histology and conduction velocity of the peroneal nerve. An increased number of the sows fed PHFO had fertility problems compared with those fed lard and PHSBO in Expt. 1, but no similar effects were seen in Expt. 2. It is concluded that consumption oftrans fatty acids with 18–22 carbon atoms from PHFO and with 18 carbon atoms from PHSBO at levels that were 5 to 12 times higher than those normally consumed by humans had no detrimental effects on female pigs or their offspring during pregnancy and lactation.