bluuebunny/crossref_metadata_2025 huggingface dataset:
Dietary manipulation of long‐chain polyunsaturated fatty acids in the retina and brain of guinea pigs
Authors: Weisinger Harrison S. , Vingrys Algis J. , Sinclair Andrew J.
Published: November 2006

High levels of n−6 docosapentaenoic acid (22∶5n−6) have been reported in the retina of guinea pigs fed commercially‐prepared grain‐based rations (commercial diet). In rats and monkeys, high levels of 22∶5n−6 are an indicator of n−3 polyunsaturated fatty acid (PUFA) deficiency. We have examined the fatty acid composition of the retina and brain in guinea pigs fed a commercial diet or one of three semi‐purified diets containing three different levels of n−3 PUFA. The diets comprised a diet deficient in n−3 PUFA (semi‐purified diet containing safflower oil), two diets containing α‐linolenic acid (standard commercial laboratory diet and semi‐purified diet containing canola oil), and a diet containing α‐linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid (DHA) (semi‐purified diet containing canola oil, safflower oil, and fish oil). Two groups of guinea pigs were given the diets from day 1 to 4 wk or day 1 to 8 wk, when they were sacrificed and the retinal tissues were extracted and analyzed for PUFA content by gas‐liquid chromatography. Fatty acid analyses of the retinal phospholipids of the four‐week‐old animals revealed that the group fed DHA (from the fish oil) had the highest level of DHA (32%), compared with values of 19 and 13% for the groups fed canola oil diet and commercial diet, respectively, and 2% for the group fed the diet deficient in n−3 PUFA. The levels of 22∶5n−6 in the retinal lipids were inversely related to the DHA values, being 0.6, 6.6, 11.4, and 20.6 for the fish oil, canola oil, commercial diet, and safflower oil diet groups, respectively. The long‐chain PUFA profiles in the brain phospholipids of the four‐week‐old group were similar to those from the retina. The retinal PUFA values for the eight‐week‐old animals were similar to the four‐week‐old group. The safflower oil diet induced a greater deficit of DHA in retinal lipids than has been reported in rats and monkeys fed similar diets. The guinea pigs fed the commercial diet had retinal and brain PUFA patterns similar to that produced by n−3 PUFA‐deficient diets in rats and monkeys. Guinea pigs fed the canola oil diet had significantly greater retinal DHA levels than those fed the commercial diet, but lower than those fed fish oil. The data suggest that the guinea pig has a reduced capacity for DHA synthesis from α‐linolenic acid as compared with other mammals. Supplementation of guinea pig diets with fish oil produced high retinal and brain DHA levels and prevented the accumulation of 22∶5n−6.
Elongation predominates over desaturation in the metabolism of 18∶3n−3 and 20∶5n−3 in turbot (Scophthalmus maximus) brain astroglial cells in primary culture
Authors: Tocher Dauglas R.
Published: November 2006

The origin of docosahexaenoic acid (DHA, 22∶6n−3) that accumulates in turbot brain during development was investigated by studying the incorporation and metabolismvia the desaturase/elongase pathways of [1‐14C]‐labelled polyunsaturated fatty acids (PUFA) in primary cultures of brain astrocytic glial cells. There was little specificity evident in the total incorporation of PUFAs into the turbot astrocytes. However, specificity was apparent in the distribution of the various PUFAs among the individual lipid classes. In particular, there was very specific incorporation of [14C]arachidonic acid (AA, 20∶4n−6) into phosphatidylinositol balanced by a lower incorporation of this acid into total diradyl glycerophosphocholines. [14C]‐Linolenic acid (LNA, 18∶3n−3) and [14C]eicosapentaenoic acid (EPA, 20∶5n−3) were metabolizedvia the desaturase/elongase pathways to a significantly greater extent than [14C]linoleic acid (18∶2n−6) and [14C]AA. The turbot astrocytes expressed very little Δ5 desaturase activity and only low levels of Δ4 desaturation activity. Although the percentages were small, approximately 4–5 times as much labelled DHA was produced from [14C]EPA compared with [14C]LNA. However, it was concluded that very little DHA in the turbot brain could result from the metabolism of LNA and EPA in astrocytic glial cells.
Relationship between mouse liver Δ9 desaturase activity and plasma lipids
Authors: de Antueno Roberto J. , Cantrill Richard C. , Huang Yung‐Sheng , Elliot Michele , Horrobin David F.
Published: November 2006

This study was undertaken to investigate the total plasma fatty acid composition and the relationship between plasma triacylglycerol (TG) levels and liver Δ9 desaturase activity in mice fed n−3 and/or n−6 fatty acid or hydrogenated coconut oil (HCO) (maximum 25 mg/g) supplemented diets. Generally, plasma TG levels and Δ9 desaturase activity were inversely correlated with the ratio of the sum of long chain n−3 fatty acids to 18∶2n−6 and to the ratio of the sum of long chain n−3 fatty acids to 18∶n−3, but they were positively correlated with the ratio of products and substrates (18∶1/18∶0) of the enzyme in plasma total lipids. The n−3 fatty acid (mainly 20∶5n−3) enriched diet, when compared to the HCO diet at 21 d, caused a significant reduction in plasma TG levels but not in Δ9 desaturase activity. However, a marked reduction in plasma TG content (50–60%) and Δ9 desaturase activity (55–70%) was observed when both 20∶5n−3 and 18∶3n−6 were supplemented in the diet. The plasma TG levels and Δ9 desaturase activity rose again when the animals were fed the HCO diet or chow. The results suggest that low dose supplementation of a mixture of n−3 (mainly 20∶5n−3) and n−6 (18∶3n−6) fatty acids modified both plasma TG content and liver Δ9 desaturase activity, in parallel.
Age‐related changes in Δ6 and Δ5 desaturase activities in rat liver microsomes
Authors: Maniongul C. , Blond J. P. , Ulmann L. , Durand G. , Poisson J. P. , Bézard J.
Published: November 2006

Age‐related changes in Δ6 desaturation of [1‐14C]α‐linolenic acid and [1‐14C]linoleic acid and in Δ5 desaturation of [2‐14C]dihomo‐γ‐linolenic acid were studied in liver microsomes from Wistar male rats at various ages ranging from 1.5 to 24 mon. Desaturase activities were expressed both as specific activity of liver microsomes and as the capacity of whole liver to desaturate by taking into account the total amount of liver microsomal protein. Δ6 Desaturation of α‐linolenic acid increased from 1.5 to 3 mon and then decreased linearly up to 24 mon to reach the same desaturation capacity of liver measured at 1.5 mon. The capacity of liver to desaturate linoleic acid increased up to 6 mon and then remained constant, whereas microsomal specific activity was equal at 1.5 and 24 mon of age. The capacity of liver to convert dihomo‐γ‐linolenic acid to arachidonic acid by Δ5 desaturation decreased markedly from 1.5 to 3 mon. It then increased to reach, at 24 mon, the same level as that observed at 1.5 mon. Age‐related changes in the fatty acid composition of liver microsomal phospholipids at the seven time points studied and of erythrocyte lipids at 1.5 and 24 mon were consistent with the variations in desaturation capacity of liver. In particular, arachidonic acid content in old rats was slightly higher than in young rats whereas contents in linoleic and docosahexaenoic acids varied little throughout the life span. The results suggest that, in liver, the activity of desaturases may be regulated in the course of aging to maintain a constant level of polyunsaturated fatty acids in cellular membranes.
Conversion of 13(S)‐hydroperoxy‐9(Z),11(E)‐octadecadienoic acid to the corresponding hydroxy fatty acid by KOH: A kinetic study
Authors: Simpson Thomas D. , Gardner Harold W.
Published: November 2006

Transformation of 13(S)‐hydroperoxy‐9(Z),11(E)‐octadecadienoic acid (13S‐HPOD) to 13(S)‐hydroxy‐9(Z),11(E)‐octadecadienoic acid (13S‐HOD) under alkaline conditions (0.05 to 5 M KOH) occurred first‐order with respect to 13S‐HPOD concentration. Overall yield was about 80%. The energy of activation at higher concentrations (3.75 to 5 M KOH) was determined to be in the range of 15.3 to 15.6 kcal. Compared to the 13S‐HPOD conversion, 13(S)‐hydroperoxy‐9(Z),11(E),15(Z)‐octadecatrienoic acid (13S‐HPOT) was converted at a faster rate to the corresponding hydroxy fatty acid (13S‐HOT), with the reaction also being first‐order. Chiral phase high‐performance liquid chromatography demonstrated that in the transformation the stereochemistry of both the 13S‐HPOD and 13S‐HPOT reactants was preserved. Manometric analyses of the KOH/13S‐HPOD reaction showed an uptake of gas, which amounted to 11% of the mols of reactant 13S‐HPOD on the assumption that the gas was O2. As there is a theoretical loss of 1 oxygen atom in the reaction, the fate of this oxygen (possiblyvia active oxygen species) may involve reaction with 13S‐HPOD/13SHOD to form the 20% by‐products.
Identification of core aldehydes amongin vitro peroxidation products of cholesteryl esters
Authors: Kamido H. , Kuksis A. , Marai L. , Myher J. J.
Published: November 2006

Synthetic cholesteryl 5‐oxovalerate and 9‐oxononanoate were used as reference standards for the isolation and identification of cholesteryl ester core aldehydes fromtert‐butyl hydroperoxide/Fe++ oxidation of synthetic and natural cholesteryl esters. The core aldehydes were recovered from the peroxidation products by thin‐layer chromatography as the free aldehydes or the 2,4‐dinitrophenylhydrazones and were identified, respectively, by gas‐liquid chromatography (GLC) and by GLC combined with mass spectrometry (GC/MS) or by reverse‐phase high‐performance liquid chromatography (HPLC) and by HPLC with MS (LC/MS). The core aldehydes produced by peroxidation of cholesteryl linoleate were identified as mainly 9‐oxononanoates of cholesterol and oxycholesterols, with smaller amounts of the 8‐oxooctenoates, 10‐oxodecenoates, 11‐oxoundecenoates and 12‐oxododecenoates. Peroxidation of cholesteryl arachidonate yielded 5‐oxovalerates of cholesterol and the oxycholesterols as the main products with smaller amounts of the 4‐oxobutyrates, 6‐oxohexenoates, 7‐oxoheptenoates, 8‐oxooctenoates, 9‐oxononenoates, 9‐oxononadienoates and 10‐oxodecadienotes. The oxycholesterols resulting from the peroxidation of the steroid ring were identified as mainly 7‐keto‐, 7α‐hydroxy‐ and 7β‐hydroxy‐cholesterols and 5α, 6α‐and 5β,6β‐epoxy‐cholestanols. Cholesteryl palmitate and oleate did not yield core aldehydes in the present peroxidation system. In these esters, the sterol and linoleic acid moieties appeared to be oxygenated at about the same rate, while the arachidonic acid moiety reacted more rapidly than did the sterol moiety.
Characteristics of the thiobarbituric acid reactivity of human urine as a possible consequence of lipid peroxidation
Authors: Kosugi Hiroko , Kojima Takashi , Kikugawa Kiyomi
Published: November 2006

A 532 nm red pigment formed in the thiobarbituric acid (TBA) assay of human urine was characterized after separation of the pigment by high‐performance liquid chromatography. The yield of the red pigment was some‐what higher at pH 2 than at pH 5; its development was not inhibited by ethylenediaminetetraacetic acid. The characteristics of the pigment were similar to those of the pigment derived from standard malonaldehyde. The amount of the pigment formed was roughly equal to the content of malonaldehyde derivatives estimated as 1‐(2,4‐dinitrophenyl)pyrazole. Pigment formation was significantly enhanced byt‐butyl hydroperoxide (t‐BuOOH) and ferric ions, which may be due to pigment formed from aldehydes other than malonaldehyde; the presence of these aldehydes was confirmed by the formation of the corresponding 2,4‐dinitrophenylhydrazones. The amount of pigment produced from 24‐h urine samples of 12 healthy subjects was estimated to be 26–95 nmol/kg, and 65–182 nmol/kg in the presence oft‐BuOOH. These values are lower than those for urine of rabbit or rat. The TBA reactivity in the absence and presence oft‐BuOOH of human urine was not related to age or sex. The TBA reactivity of human urine collected in the afternoon and in the evening was higher than that of urine collected in the morning.
Fatty acids in the lipids ofDrosophila heads: Effects of visual mutants, carotenoid deprivation and dietary fatty acids
Authors: Stark William S. , Lin Teng‐Nan , Brackhahn David , Christianson J. Scott , Sun Grace Y.
Published: November 2006

Lipids ofDrosophila heads were extracted and separated by high‐performance thin‐layer chromatography. Fatty acid compositions of major phospholipids as well as of triglycerides were analyzed by gas‐liquid chromatography. Proportions of the major fatty acids (14∶0, 16∶0, 16∶1, 18∶0, 18∶1, 18∶2, 18∶3) varied depending on the lipid analyzed. Docosahexaenoic acid (22∶6), common in vertebrate photoreceptors and brain, and arachidonic acid (20∶4), a precursor of eicosanoids, were lacking. A comparison of the fatty acid composition of the dietvs. the head suggested thatDrosophila can desaturete but may not be able to elongate fatty acid carbon chains. Fatty acid analyses were carried out after the following visual system alterations: i) the transduction mutant whereno receptorpotential results from a deficit in phospholipase C; ii) an allele ofeyes absent; iii) the mutantouterrhabdomeresabsent which lacks visual pigment and rhabdomeres in the predominant type of compound eye receptor, rhabdomeres 1 through 6; and iv) carotenoid deprivation which reduces opsin and rhabdomere size. We also evaluated aging by comparing newly‐emergedvs. aged wild‐type flies. Alterations in fatty acid composition based on some of these manipulations were found. Based on comparisons between flies reared on media differing in C16 and C18, there is an indication that diet readily affects tissue fatty acid composition.
Incorporation oftrans long‐chain n−3 polyunsaturated fatty acids in rat brain structures and retina
Authors: Grandgirard A. , Bourre J. M. , Julliard F. , Homayoun P. , Dumont O. , Piciotti M. , Sebedio J. L.
Published: November 2006

During heat treatment, polyunsaturated fatty acids and specifically 18∶3n−3 can undergo geometrical isomerization. In rat tissues, 18∶3 Δ9c, 12c, 15t, one of thetrans isomers of linolenic acid, can be desaturated and elongated to givetrans isomers of eicosapentaenoic and docosahexaenoic acids. The present study was undertaken to determine whether such compounds are incorporated into brain structures that are rich in n−3 long‐chain polyunsaturated fatty acids. Two fractions enriched intrans isomers of α‐linolenic acid were prepared and fed to female adult rats during gestation and lactation. The pups were killed at weaning. Synaptosomes, brain microvessees and retina were shown to contain the highest levels (about 0.5% of total fatty acids) of thetrans isomer of docosahexaenoic acid (22∶6 Δ4c, 7c, 10c, 13c, 16c, 19t). This compound was also observed in myelin and sciatic nerve, but to a lesser extent (0.1% of total fatty acids). However, the ratios of 22∶6trans to 22∶6cis were similar in all the tissues studied. When the diet was deficient in α‐linolenic acid, the incorporation oftrans isomers was apparently doubled. However, comparison of the ratios oftrans 18∶3n−3 tocis 18∶3n−3 in the diet revealed that thecis n−3 fatty acids were more easily desaturated and elongated to 22∶6n−3 than the correspondingtrans n−3 fatty acids. An increase in 22∶5n−6 was thus observed, as has previously been described in n−3 fatty acid deficiency. These results encourage further studies to determine whether or not incorporations of suchtrans isomers into tissues may have physiological implications.
Hepatic phospholipid molecular species in the guinea pig adaptations to pregnancy
Authors: Burdge Graham C. , Postle Anthony D.
Published: November 2006

Incorporation of polyunsaturated fatty acids (PUFA), particularly 22∶6n−3, into fetal brain at specific gestational ages is critical for development of normal brain function. We have studied adaptations to maternal liver phospholipid molecular species compositions that may be related to the supply of PUFA to fetal brain. The increment of 22∶6n−3 in brain phosphatidylethanolamine (PE) was maximal at day 25 to day 35 of gestation, consistent with early prenatal development of guinea pig brain. At the same gestational ages, there was a transient increase in maternal liver concentration of 16∶0/22∶6 phosphatidylcholine (PC), which preceded the progressive increase in total PC concentration toward term (day 68). This effect was specific for thesn‐1 16∶0 species, as, there was no significant increase in 18∶0/22∶6 PC concentration. These results are consistent with a specific role for 16∶0/22∶6 PC in the directed supply of 22∶6n−3 from maternal liver to the fetus. Concentrations of all PE species in maternal liver decreased at day 25 and day 35 of gestation. The gradual accumulation of 22∶6n−3 in fetal liver throughout gestation did not correlate with the pattern of acquisition of 22∶6n−3 into fetal brain PE. Maternal plasma PC and cholesterol concentrations decreased dramatically by day 25 of gestation, and remained low until term. This hypolipidemia of pregnancy in the guinea pig may be due to increased lipase‐mediated turnover of plasma lipoproteins and contrasts strongly with the well‐characterized hyperlipidemia in human and rat gestation.
Dietary protein deficiency affects n−3 and n−6 polyunsaturated fatty acids hepatic storage and very low density lipoprotein transport in rats on different diets
Authors: Bouziane Mahmoud , Prost Josiane , Belleville Jacques
Published: November 2006

Fatty livers and the similarity between the skin lesions in kwashiorkor and those described in experimental essential fatty acid (EFA) deficiency have led to the hypothesis that protein and EFA deficiencies may both occur in chronic malnutrition. The relationship between serum very low density lipoprotein (VLDL) and hepatic lipid composition was studied after 28 d of protein depletion to determine the interactions between dietary protein levels and EFA availability. Rats were fed purified diets containing 20 or 2% casein and 5% fat as either soybean oil rich in EFA, or salmon oil rich in eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, or hydrogenated coconut, oil poor in EFA. Animals were divided into six groups, SOC (20% casein +5% soybean oil), SOd (2% casein +5% soybean oil), COC (20% casein +5% hydrogenated coconut oil), COd (2% casein + 5% hydrogenated coconut oil), SAC (20% casein +5% salmon oil) and SAd (2% casein +5% salmon oil). After 28 d, liver steatosis and reduced VLDL‐phospholipid contents (P<0.001) were observed in protein‐deficient rats. In protein deficiency, triacylglycerol and phospholipid fatty acid compositions in both liver and VLDL showed a decreased polyunsaturated‐to‐saturated fatty acid ratio. This ratio was higher with the salmon oil diets and lower with the hydrogenated coconut oil diets. Furthermore, independent of the oil in the diet, protein deficiency decreased linoleic and arachidonic acids in VLDL phospholipids. Conversely, despite decreased proportions of EPA at low protein levels, DHA levels remained higher in rats fed salmon oil diets. While in rats fed the hydrogenated coconut oil‐fed diets the amount of 22∶5n−6 was lower in liver, it was higher in VLDL lipids at low protein levels. Both EPA and arachidonic acid are precursors of eicosanoids and their diminution may be related to certain clinical symptoms seen in infants suffering from kwashiorkor.
Boreal freshwater fish diet modifies the plasma lipids and prostanoids and membrane fatty acids in man
Authors: Ågren J. J. , Hänninen O. , Laitinen M. , Seppänen K. , Bernhardt I. , Fogelholm L. , Herranen J. , Penttila I.
Published: November 2006

The effect of fish diet on 43 healthy male students was studied. They ate a fish‐containing meal for 15 weeks on an average of 3.7 times per week. Twenty‐one of them voluntarily restricted their lipid intake while the rest ate normally. Controls continued their usual eating habits (19 students). The meals consisted of Finnish freshwater fish (87%) (vendace, pike, perch and rainbow trout) and brackish water fish (13%) (Baltic herring) that provided about 1 g of ω‐3 polyunsaturated fatty acids per day (0.25 g eicosapentaenoic acid and 0.55 g docosahexaenoic acid). During the diet, ω‐3 fatty acids increased in erythrocyte ghosts and platelets at the expense of ω‐6 fatty acids. The concentration of serum cholesterol diminished in those fish consumers who lowered their lipid intake. Apolipo‐protein A1 and B were lowered in both fish‐consuming groups. Triglyceride levels also showed a tendency to decrease. The formation of thromboxane B2 during incubation of whole blood decreased in both fish‐consuming groups. The decrease of plasma 6‐keto‐PGF1α was not statistically significant, if compared with the controls. The results obtained indicate that a moderate intake of fish‐containing meals has some beneficial effects on the plasma lipid and prostanoid metabolism, when coronary heart disease risk factors are considered.
Hydrolysis of a fluorescent substance formed from an oxidized phospholipid and an amino compound by phospholipase A2
Authors: Iio Toshihiro , Yoden Kazuaki
Published: November 2006

Phosphatidylcholine hydroperoxide produced a fluorescent substance (FS‐III) through reaction with 1‐aminopentane after preincubation with heme methyl ester as a model system. The FS‐III was retained at the 2‐position of the glycerol backbone of phosphtidylcholine without breakdown into low molecular weight compounds. Phosphatidylcholine oxidized by catalysis with ferrous ion and ascorbic acid also produced the same fluorescent substance (FS‐III). Phospholipase A2 specifically hydrolyzed the FS‐III attached to the phospholipid, making it possible to elute the same fluorescent substance (FS‐II) as that obtained from oxidized methyl linoleate. The release of FS‐II by hydrolysis of FS‐III attached to phospholipid increased with greater phospholipase A2 activity. It is suggested that, with aging, the accumulation of fluorescent lipofuscin pigments in biomembranes may be related to changes in the peroxidized phospholipid content and that phospholipase A2 may play a role in decreasing the formation and accumulation of fluorescent phospholipids in biomembranes.
Dietary linoleic acid and the fatty acid profiles in rats fed partially hydrogenated marine oils
Authors: Høy C. ‐E. , Hølmer G.
Published: November 2006

The influence of the linoleic acid levels of diets containing partially hydrogenated marine, oils (HMO) rich in isomeric 16∶1, 18∶1, 20∶1 and 22∶1 fatty acids on the fatty acid profiles of lipids from rat liver, heart and adipose tissue was examined. Five groups of rats were fed diets containing 20 wt% fat−16% HMO+4% vegetable oils. In these diets, the linoleic acid contents varied between 1.9% and 14.5% of the dietary fatty acids, whereas the contents oftrans fatty acids were 33% in all groups. A sixth group was fed a partially hydrogenated soybean oil (HSOY) diet containing 8% linoleic acid plus 32%trans fatty acids, mainly 18∶1, and a seventh group, 20% palm oil (PALM), with 10% linoleic acid and notrans fatty acids.

As the level of linoleic acid in the HMO diets increased from 1.9% to 8.2%, the contents of (n−6) polyunsaturated fatty acids (PUFA) in the phospholipids increased correspondingly. At this dietary level of linoleic acid, a plateau in (n−6) PUFA was reached that was not affected by further increase in dietary 18∶2(n−6) up to 14.5%. Compared with the HSOY‐ or PALM‐fed rats, the plateau value of 20∶4(n−6) were considerably lower and the contents of 18∶2(n−6) higher in liver phosphatidylcholines (PC) and heart PC. Heart phosphatidylethanolamines (PE) on the contrary, had elevated contents of 20∶4(n−6), but decreased 22∶5(n−6) compared with the PALM group.

All groups fed HMO had similar contents oftrans fatty acids, mainly 16∶1 and 18∶1, in their phospholipids, irrespective of the dietary 18∶2 levels, and these contents were lower than in the HSOY group.

High levels of linoleic acid consistently found in triglycerides of liver, heart and adipose tissue of rats fed HMO indicated that feeding HMO resulted in a reduction of the conversion of linoleic acid into long chain PUFA that could not be overcome by increasing the dietary level of linoleic acid.
Influence of dietary egg and soybean phospholipids and triacylglycerols on human serum lipoproteins
Authors: O'Brien Barbara C. , Andrews Verona Gale
Published: November 2006

Human serum lipid and lipoprotein concentrations and compositions were compared in ten healthy middle‐aged men consuming phospholipids from egg or from soybean or triacylglycerol mixtures with fatty acid compositions similar to those of the phospholipids. All subjects followed each of the four treatments: egg phospholipids (EP), soybean phospholipids (SP), an oil of fatty acid composition similar to that of EP, and an oil similar in fatty acid composition to SP for six weeks with “wash‐out” periods of similar duration between treatment periods. The phospholipids, 15 g/d, and the oils, 12 g/d, which contained approximately equivalent quantities of fatty acids were provided to the subjects in gelatin capsules and were taken before meals. Diet intake was monitored by three‐day food records. Serum lipoproteins (Lp) were separated by ultracentrifugation into very low density lipoproteins, low density lipoproteins (LDL), high density lipoproteins (HDL)2 and HDL3. Lp fractions and whole serum were analyzed for triacylglycerols, cholesterol (CH), phospholipids (PL), and protein. HDL cholesterol was determined in while serum. Cholesteryl esters were determined in some Lp fractions. Lipid compositions of Lp were expressed in mmol/g protein. Apoprotein B was measured in whole serum and in LDL; apoprotein A‐I in whole serum and in HDL3. In whole serum, CH and PL were significantly lower after the SP compared to EP treatment periods. CH, but not PL, was lower after SPTG compared to EP. CH in HDL2 was significantly higher after SP compared to SPTG. Also, PL in HDL2 were significantly higher after SP compared to all other treatments and to baseline. Although human serum lipid responses to dietary phospholipids were generally the same as responses to ingested oils of comparable fatty acid composition, the data suggest the possibility that SP selectively increase HDL2 cholesterol and phospholipids.
Molecular species composition of glycerophospholipids from white matter of human brain
Authors: Wilson Robert , Bell Michael V.
Published: November 2006

The molecular species composition of the major glycerophospholipids from white matter of human brain were determined by high‐performance liquid chromatography of the 3,5‐dinitrobenzoyl derivatives of the corresponding diradylglycerols. In phosphatidylcholine (PC) and phosphatidylserine (PS), molecular species containing only saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) comprised 85.7 and 82.4% of the respective totals, with 18∶0/18∶1 predominant in PS and 16∶0/18∶1 in PC. These molecular species were also abundant in phosphatidylethanolamine (PE), but in this phospholipid species containing polyunsaturated fatty acids (PUFA), largely 18∶0/22∶6n−3 and 18∶0/20∶4n−6, accounted for over half the total; 18∶1/18∶1 was also abundant in PE. In contrast, 1‐O‐alk‐1′‐enyl‐2‐acylsn‐glycero‐3‐phosphoethanolamine (GPE) had much more SFA‐ and MUFA‐containing species, predominantly 16∶0a/18∶1, 18∶0a/18∶1 and 18∶1a/18∶1, with low amounts of species containing 20∶4n−6 and 22∶6n−3. In alkenylacyl GPE, 22∶4n−6 was the major PUFA and 16∶0a/22∶4n−6 and 18∶1a/22∶4n−6 the main PUFA‐containing species. There was six times more 22∶6n−3, twice as much 20∶4n−6 and half the amount of 22∶4n−6 in PE as compared to alkenylacyl GPE.
Preparation of methyl 5,11,14,17‐eicosatetraenoate‐8,8,9,9‐d4
Authors: Rakoff Henry
Published: November 2006

For studies of incorporation, elongation and desaturation of fats in humans and animals, methyl 5,11,14,17‐eicosatetraenoate‐8,8,9,9‐d4 was prepared by Wittig coupling, in the presence of sodiumbis(trimethylsilyl) amide, of 6,9,12‐pentadecatrienal‐3,3,4,4‐d4 and 4‐carboxybutyltriphenylphosphonium bromide. The all‐cis isomer was separated fromtrans isomers and other impurities by silver resin chromatography. Location and configuration of the double bonds and deuterium atoms were affirmed by nuclear magnetic resonance and mass spectrometry.
Multigram synthesis of 1‐alkylamido phospholipids
Authors: Surles Jefferson R. , Morris‐Natschke Susan , Marx Michael H. , Piantadosi Claude
Published: November 2006

Phospholipids containing a 1‐alkylamido linkage have shown promisingin vitro neoplastic cell growth inhibitory properties and anti‐human immunodeficiency viral activity. We have synthesized a series of alkylamido ether lipid analogues on a milligram scale for initial evaluation, but for furtherin vivo testing of these bioactive phospholipids, synthesis on a larger scale is required. The multigram synthesis of 1‐alkylamido ether phospholipids was accomplished by modifying reaction conditions in the amidation step and changing reagents and solvent systems in both the detritylation and phosphorylation steps. This was most crucial in the phosphorylation step, where in the multigram synthesis 2‐bromoethyl dichlorophosphate in diethyl ether/tetrahydrofuran (7∶3, vol/vol) gave much improved yields as compared to the 2‐chloro‐2‐oxo‐1,3,2‐dioxaphospholane reagent. The modifications also resulted in a product that could be more easily purified in sufficient quantities for use inin vivo inhibition studies.
Composition of the phospholipids and their fatty acids in the ROC‐1 oligodendroglial cell line
Authors: Murphy Eric J. , Horrocks Lloyd A.
Published: November 2006

ROC‐1 cells are a hybrid of C−6 rat glioma and rat oligodendroglia cells. Biochemically these cells resemble the oligodendroglia parent, but their lipid composition is unknown. The phospholipid composition in mole % was: cardiolipin, 1.0; phosphatidylglycerol, 1.2; ethanolamine glycerophospholipids, 27.6; phosphatidylinositol, 5.8; lysophosphatidylethanolamine, 0.8; phosphatidylserine, 5.6; choline glycerophospholipids, 43.7; sphingomyelin, 13.7; phosphatidylinositol‐4‐monophosphate, 0.8; and lysophosphatidylcholine, 0.6. The choline and ethanolamine plasmalogens made up 7.2 and 18.4% of the total phospholipids, respectively. The phospholipid composition reflects that of both parental cells. The cells had moderate to high levels of 20∶3n−9 indicating n−6 series fatty acid deficiency. The phosphatidylinositol had very high 20∶3n−9 levels with a 20∶3n−9/20∶4n−6 ratio of 2.1 compared to 0.44 and 0.58 for ethanolamine glycerophospholipids (EtnGpl) and choline glycerophospholipids (ChoGpl) respectively. The saturated/polyenoic fatty acid ratios were 0.40 for EtnGpl, 3.38 for ChoGpl and 1.48 for phosphatidylinositol.
Lipids from the paracloacal glands of the chinese alligator (Alligator sinensis)
Authors: Dunn B. S. , Weldon P. J. , Howard R. W. , McDaniel C. A.
Published: November 2006

Lipids from the paracloacal glands of adult Chinese alligators (Alligator sinensis) were analyzed by gas chromatography/mass spectrometry. Acetates, aliphatic alcohols, free fatty acids and waxes consisting primarily of hexadecanoates were indicated in the secretions of males and females. Cholesterol, a diterpene hydrocarbon, and a diterpene ketone were detected in secretions of males but not in those of females. Lipids identified in the paracloacal secretions ofA. sinensis are compared with those reported from the American alligator and other crocodilians.
Dietary ether lipid incorporation into tissue plasmalogens of humans and rodents
Authors: Das Arun K. , Holmes Ronald D. , Wilson Golfer N. , Hajra Amiya K.
Published: November 2006

Chronic feeding of 1‐O‐octadecyl‐sn‐glycerol (batyl alcohol) to patients suffering from congenital deficiency in tissue ether glycerolipids showed an increase in the plasmalogens content of their erythrocytes. However, nothing is known about the ether lipid content of other tissues in these patients. Feeding 1‐O‐heptadecyl‐sn‐glycerol to young rats showed that this uncommon ether lipid was incorporated to a high extent into the plasmalogens of all tissues except brain. Comparative studies with other precursors, such as 3‐O‐heptadecyl‐sn‐glycerol, heptadecanol and heptadecanoic acid, indicated a stereospecific incorporation of the dietary 1‐O‐alkyl‐sn‐glycerols into tissue plasmalogens without cleavage of the ether bond. Dietary ether lipids were also shown to be transferred from mothers to suckling rats, but not from pregnant rats to fetuses. The implication of these results to possible dietary ether lipid therapy for patients suffering from peroxisomal disorders is discussed.
Abnormal lipid and fatty acid compositions of kidneys from mice with polycystic kidney disease
Authors: Aukema H. M. , Yamaguchi T. , Takahashi H. , Celi B. , Holub B. J.
Published: November 2006

Renal cyst development in polycystic kidney disease (PKD) involves hyperplastic growth and extensive membrane alterations, suggesting abnormal membrane composition and function. Using thin‐layer and gas‐liquid chromatography, we analyzed the lipid components of the kidneys from 120‐day‐old DBA/2FG‐pcy (pcy) having PKD as compared to normal DBA/2J (DBA) mice. At sacrifice, kidneys frompcy mice were four times larger than DBA controls, indicating that extensive renal cyst growth had occurred. The ratios of cholesterol/phospholipid, choline glycerophospholipid (GPC)/ethanolamine glycerophospholipid (GPE) and alkenylacyl GPE/diacyl GPE were higher (by 25%, 41% and 72%, respectively) in the cystic kidneys, while total phosphatidylinositol (PI), GPE and cardiolipin (DPG) were lower (by 13%, 23% and 27%, respectively). With respect to fatty acid compositions, there were significantly lower levels of docosahexaenoic acid (DHA, 22∶6n−3) and higher levels of adrenic acid (AdA, 22∶4n−6) in the phospholipids ofpcy mouse kidneys. These changes were not present in serum, indicating that they were not generalized differences. Interestingly, the lower level of DHA in GPE was found to be associated with the alkenylacyl, but not the diacyl species. The fatty acids comprising the product/substrate ratio for the Δ4 desaturase activity were lower across all phospholipids, indicating a possible abnormality in polyunsaturated fatty acid metabolism in this model of PKD. These lipid abnormalities may influence membrane‐mediated events such as receptor activation, signal transduction, ion transport and enzyme activities. The renal pathophysiologies associated with PKD may be related to the tissue lipid abnormalities described herein.
Oxidation of the α‐tocopherol model compound 2,2,5,7,8‐pentamethyl‐6‐chromanol in the presence of alcohols
Authors: Suarna Cacang , Baca Manuel , Southwell‐Keely Peter T.
Published: November 2006

Oxidation of the vitamin E model compound, 2,2,5,7,8‐pentamethyl‐6‐chromanol (1b) byt‐butyl hydroperoxide in chloroform has been studied in the presence of ethanol, heptanol and cholesterol. In the absence of an alcohol, the major products were the spirodimer (13b) and spirotrimer (14b) of 1b, together with 1H,2,3‐dihydro‐3,3,5,6,9,10,11a(R)‐heptamethyl‐7a(S)‐(3‐hydroxy‐3‐methylbutyl)‐pyrano[2,3‐a] xanthene 8(7aH), 11(11aH) dione (6b). In the presence of ethanol, heptanol and cholesterol, the major products were 5‐ethoxymethyl‐2,2,7,8‐tetramethyl‐6‐chromanol (16b), 5‐heptoxymethyl‐2,2,7,8‐tetramethyl‐6‐chromanol (17) and 5‐cholesteroxymethyl‐2,2,7,8‐tetramethyl‐6‐chromanol (18). However, when water was present in a homogeneous reaction, the most rapidly formed product was 2‐(3‐hydroxy‐3‐methylbutyl)‐3,5,6‐trimethyl‐1,4‐benzoquinone (5b). Compounds 13b, 14b, 16b, 17 and 18 are formedvia a quinone methide intermediate, and compound 5b is formedvia a phenoxylium ion. The phenoxylium species appears to be the preferred intermediate when water is present, whereas the quinone methide species is prefered in the absence of water.
Low‐density lipoprotein turnover in inbred strains of rabbits hypo‐ or hyperresponsive to dietary cholesterol
Authors: Meijer G. W. , Stalenhoef A. F. H. , Demacker P. N. M. , Mol M. J. T. M. , Van Zutphen L. F. M. , Beynen A. C.
Published: November 2006

In two inbred strains of rabbits with high or low response of plasma cholesterol to dietary cholesterol, low density lipoprotein (LDL) apolipoprotein (apoLDL) kinetics were determined with the use of a heterologous tracer isolated from a Watanabe heritable hyperlipidemic (WHHL) rabbit. On a diet without added cholesterol, the total clearance of apoLDL (which equals apoLDL production) did not differ significantly between rabbits of both strains. After the feeding of a diet containing 0.1% cholesterol for six weeks, plasma LDL cholesterol, plasma apoLDL and liver cholesterol concentrations rose significantly in the hyperresponsive but not in the hyporesponsive rabbits. Cholesterol feeding depressed the total fractional catabolic rate (FCR) of apoLDL in the hyper‐ but not in the hyporesponsive rabbits; this was attributed to a decrease of receptor‐dependent FCR while receptor‐independent FCR was similar in the two strains. On the diet containing cholesterol, the receptor‐mediated absolute catabolic rate (ACR) of apoLDL did not differ between hyper‐ and hyporesponsive rabbits but receptor‐independent ACR of apoLDL was higher in hyperresponders. It is concluded that the higher plasma apoLDL levels in hyperresponsive rabbits fed the 0.1% cholesterol diet are caused by a higher production of apoLDL and not by a lower flux of apoLDL through the receptor‐mediated pathway.
Occurrence of a novel sterol, 24,25‐methylenecholest‐5‐en‐3β‐ol, inMortierella alpina 1S‐4
Authors: Shimizu Sakayu , Kawashima Hiroshi , Wada Masaru , Yamada Hideaki
Published: November 2006

24,25‐Methylenecholest‐5‐en‐3β‐ol, which has not been reported previously to exist in nature, was isolated from mycelia of an arachidonic acid‐producing fungus,Mortierella alpina 1S‐4. Desmosterol, ergosta‐5,24(25)‐dien‐3β‐ol and ergosta‐5,25‐dien‐3β‐ol were also found in the fungus, but ergosterol and cholesterol were not detected.
Effect of different acids with Δ9,12‐dienoic structures on Δ9 desaturation activity in rat liver microsomes
Authors: de Alaniz Maria J. T. , de Gomez Dumm Irma N. T. , Brenner Rodolfo R.
Published: November 2006

The effect of oral administration, for 24 or 48 hr, of different octadeca fatty acids containing a 9,12‐dienoic structure on the fatty acid composition and Δ9 desaturation activity of liver microsomes of rat fed a fat‐free diet was studied. The ethyl esters of linoelaidic and γ‐linolenic acids, the methyl ester of linoleic acid and free columbinic acid were administered to rats maintained on a fat‐free diet. The supplementation of the fat‐free diet with linoelaidate produced no relevant changes in the fatty acid composition pattern of liver microsomes and did not modify the percentage of conversion of palmitic to palmitoleic acid. The addition of linoleate or γ‐linolenate to the fat‐free diet returned liver microsome Δ9 desaturation activity toward the control and partially restored the liver microsome fatty acid spectrum found in the fat‐free diet. Columbinic acid (5‐trans‐9‐cis,12‐cis‐18∶3), which cannot be transformed into arachidonic acid, also decreased the Δ9 desaturation activity enhanced by the fat‐free diet and evoked changes in the microsomal fatty acid composition similar to those produced by the ω6 fatty acids. These results suggest that the modulation of Δ9 desaturase activity evoked by dietary administration of unsaturated acids of ω6 series would depend on thecis double bond configuration of these acids.
Fatty acids in crinoidea and ophiuroidea: Occurrence of all‐cis‐6,9,12,15,18,21‐tetracosahexaenoic acid
Authors: Takagi Toru , Kaneniwa Masaki , Itabashi Yutaka
Published: November 2006

The fatty acid compositions of lipids from two species of Crinoidea and two species of Ophiuroidea have been investigated with open‐tubular gas chromatography. About 5–10% of tetracosahexaenoic acid was found in total fatty acids from all the samples, and the structure was determined as all‐cis‐6,9,12,15,18,21‐tetracosahexaenoic acid [24∶6(n−3)] by13C‐NMR of the methyl esters and mass spectrometric analyses of the methyl esters, the pyrrolidides and the ozonolysis products. The 24∶6(n−3) was concentrated in the polar lipids rather than neutral lipids. The n−3 hexaenoic structure suggested chain elongation of 22∶6(n−3) as the source.

The 5‐olefinic acids (5−18∶1, 5−20∶1, 5,11‐ and 5,13−20∶2) were low in Crinoidea (0.2–1.3%) but were present in higher levels (2.5–5.2%) in Ophiuroidea. Polyunsaturated acids found other than 24∶6(n−3) were 20∶4(n−6), 20∶5(n−3) and 22∶6(n−3) as major components and 16∶3(n−3), 18∶2(n−6), 18∶3(n−6), 18∶3(n−3), 18∶4(n−3), 20∶2(n−9), 20∶2(n−6), 20∶3(n−6), 20∶3(n−3), 21∶5(n−3) and 22∶5(n−3) as minor components in all the samples.
Effects of estradiol and environmental temperature changes on rat liver Δ6 microsomal desaturase activity
Authors: Gonzalez Susana , Nervl Anibal M. , Peluffo Raul O.
Published: November 2006

The regulation of Δ6 desaturase activity by environmental temperature changes was studied in the microsomal membranes from female and ovariectomized female rat liver. Female rats adapted at 30–32 C for 20–25 days and then shifted to 13–15 C for 5 days showed an increased Δ6 desaturase system. Ovariectomized rats adapted under the same conditions did not show significant changes in this enzyme. The fatty acid compositions of microsomal phosphatidylcholine showed a decrease in arachidonic acid in female rats at 30 C compared to females at 15 C and ovariectomized rats at both temperatures. These results suggest that a modification of ovaric sex hormone levels might be responsible for the different Δ6 desaturase activity in female rats acclimated at both temperatures. In this regard, serum estradiol radioimmunoassay yielded slight differences between the two groups of female rats, suggesting that estradiol could play a role in the regulation of the Δ6 desaturase. The administration of a pharmacological dose of 17‐β estradiol to female and ovariectomized rats kept at 30 and 15 C decreased the Δ6 microsomal desaturase activity. These data suggest that estradiol levels are involved in the regulation of the Δ6 desaturase during cold adaptation.
Metabolism and incorporation into glycerolipids of exogenous 18∶3(n−3) and 18∶3(n−6) by MDCK cells
Authors: Lynch Robert D. , Locicero Jean , Schneeberger Eveline E.
Published: November 2006

The extent to which exogenous 18∶3(n−3) and 18∶3(n−6) were desaturated and elongated and the degree to which they and their derivatives altered the unsaturation index of cell glycerolipids were compared using clone 4 MDCK cells grown in lipid‐ and serum‐free medium. Despite differences in the degree of unsaturation of the individual polyunsaturated fatty acids produced from 18∶3(n−3) or 18∶3(n−6), the unsaturation index of phospholipids increased similarly from 0.7 in control cells grown in serum‐ and lipid‐free medium to ca. 1.6 in those supplemented with fatty acid. The added fatty acids had little effect on cell growth. The conversion of 18∶3(n−6) to 20∶3(n−6) and 20∶4(n−6) was more rapid than that of 18∶3(n−3) to 20∶4(n−3) and 20∶5(n−3). No significant quantities of 20∶3(n−3) or 18∶4(n−3) were noted. When both 18∶3 isomers were supplied simultaneously, marked differences in the amounts of some species of n−3 and n−6 polyunsaturated fatty acids were observed. The presence of 18∶3(n−6) and/or its derivatives suppressed levels of 20∶4(n−3) and 20∶5(n−3), perhaps through inhibition of the Δ6 and Δ5 desaturases responsible for their synthesis from 18∶3(n−3). Similarly 18∶3(n−3), and/or its longer more unsaturated derivatives, diminished the formation of 20∶4(n−6) from 18∶3(n−6). No marked effect on the products derived from elongation alone were observed.
Effect of nutritional status on the fatty acid composition of rat liver and cultured hepatocytes
Authors: Nelson Gary J. , Kelley Darshan S. , Hunt James E.
Published: November 2006

The lipid concentration and fatty acid composition of the whole liver and of cultured hepatocytes isolated from the livers of rats fed ad libitum (fed), fasted for 24 hr (fasted), or fasted for 48 hr and then refed a fat‐free, high carbohydrate diet for 48 hr (refed) was studied. Hepatocytes were maintained as monolayer cultures in serum‐free, lipid‐free media and their fatty acid composition was analyzed at 3, 24, 48, 72 and 96 hr. The livers of fed animals, as well as their hepatocytes, contained less total lipid than those from animals on either of the other dietary regimes. Livers of fasted animals had three times the amount of lipid found in the livers of fed animals, and the livers of refed animals contained five times the amount of lipid as the livers of fed animals (all based on mg lipid/g wet weight of liver). The fatty acid composition of hepatocytes after 3 hr of culturing was very similar to that of fresh liver when compared in each of the dietary regimes. However, while the fatty acid compositions of livers and hepatocytes from fed and fasted animals were similar, the pattern in liver of refed animals was quite distinct from that of the fed animals. In the fed and fasted animals palmitic acid (16∶0), stearic acid (18∶0), oleic acid (18∶1[n‐9]), linoleic acid (18∶2[n‐6]) and arachidonic acid (20∶4[n‐6]) were the major fatty acids of the liver; in refed animals 16∶0, palmitoleic acid (16∶1[n‐7]), 18∶0, 18∶1(n‐9) andcis‐vaccenic acid (the n‐7 isomer of oleic acid) were the major fatty acids. During maintenance in culture the 18∶1(n‐9) content of the hepatocytes increased in cells from livers of animals on all three dietary regimes. The polyunsaturated fatty acid content was similar in fresh livers and isolated hepatocytes in all samples when compared on the basis of μg fatty acid/mg of hepatocyte or liver protein. It was also found that the polyunsaturated fatty acid content of hepatocytes was remarkedly stable with time of culture when the cells were incubated in serum‐free, lipid‐free medium. Thus, isolated hepatocytes maintained in serum‐free medium appear to be a possible system for the evaluation of the effects of prior nutritional status on fatty acid metabolism in the whole animal, not subject to hormonal and other somatic influences which often complicate the interpretation of such nutritional studies.
Glycerolipid biosynthesis in rat adipose tissue. Influence of age and cell size on substrate utilization
Authors: Jamdar Subhash C. , Osborne Linda J. , Wells Gary N.
Published: November 2006

The conversion of [14C]‐labeled compounds such as acetate, glucose, pyruvate and palmitate into CO2, glyceride‐glycerol, glyceride fatty acids and total lipids was monitored in the average and matching adipocyte (with respect to size) preparations from young (6–9 wk) and old (age 56–60 wk) male Sprague‐Dawley rats. The average cell size populations from young and old rats were 46±3 and 83±11 μm in diameter, respectively. The incorporation of [14C]acetate, pyruvate and glucose into fatty acids was significantly reduced in the adipocytes from older rats, irrespective of their sizes. The production of CO2and glyceride‐glycerol did not change significantly as a function of either cell size or animal age. Palmitate incorporation into lipids was similar in the average cell population derived from old and young rats, but it was considerably lower in the smaller adipocytes (46–50 μm diameter) from old animals. Irrespective of the cell size, triacylglycerol formation fromsn‐glycerol‐3‐phosphate was also significantly diminished in the adipocytes from older animals compared to younger ones as evidenced by decreases in activities of several enzymes, includingsn‐glycerol‐3‐phosphate acyltransferase, Mg2+‐dependent phosphatidate phosphohydrolase and diacylglycerol acyltransferase. However, triacylglycerol formation from monoacylglycerol did not change as a function of either cell size or age. These measurements of the metabolic and enzymic activities provide evidence that the synthesis of fatty acids from various precursors and triacylglycerol formation fromsn‐glycerol‐3‐phosphate are significantly reduced in adipocytes from older animals and that such changes occur independently of adipocyte size.