bluuebunny/crossref_metadata_2025 huggingface dataset:
Vitamin A deficiency enhances docosahexaenoic and Osbond acids in liver of rats fed an α‐linoleic acid‐adequate diet
Authors: Zhou D. , Ghebremeskel K. , Crawford M. A. , Reifen R.
Published: February 2007

The synthesis of docosahexaenoic (DHA, 22∶6n−3) and Osbond acid (OA, 22∶5n−6) is regulated by the heterodimer of peroxisome proliferator‐activated receptor and retinoid X receptor (RXR). 9‐Cis retinoic acid, a metabolite of vitamin A, is the most potent ligand of RXR. We tested whether vitamin A deficiency impairs DHA and OA synthesis in rats fed a vitamin A‐ and α‐linolenic acid (ALA)‐sufficient (VASALAS), vitamin A‐sufficient and ALA‐deficient (VASALAD), vitamin A‐deficient and ALA‐sufficient (VADALAS), or vitamin A‐ and ALA‐deficient (VADALAD) diet. After 7 wk of feeding, liver and colon choline (CPG) and ethanolamine (EPG) phosphoglyceride FA were analyzed. The VADALAS compared with the VASALAS rats had elevated levels of both DHA (P<0.05) and OA (P<0.05) in liver CPG and EPG. In contrast, the VADALAD group had a lower DHA (P<0.01) and higher OA (P<0.005) level in CPG and EPG of both tissues than their VASALAD counterparts. ALA deficiency reduced DHA and enhanced OA levels in liver and colon CPG and EPG in both the vitamin A‐sufficient (VASALAS vs. VASALAD) and‐deficient (VADALAS vs. VADALAD) rats (P<0.005). The study demonstrates that ALA deficiency reduced DHA and enhanced OA levels in tissue membranes, and dietary vitamin A deficiency has a profound effect on membrane DHA and OA in rat tissues. Both vitamin A and DHA are involved in a myriad of vital physiological functions pertaining to growth and development and health. Hence, there is a need for a further study to unravel the mechanism by which vitamin A influences membrane DHA and OA.
Effects of geographic source, rearing system, and season on the nutritional quality of wild and farmed Perca fluviatilis
Authors: Mairesse Guillaume , Thomas Marielle , Gardeur Jean‐Noël , Brun‐Bellut Jean
Published: February 2007

The effects of season, geographic source (Lake Geneva, Rhine River), and rearing system (extensive, semiextensive, and intensive systems) on the lipid content and FA composition of fillets of Perca fluviatilis were studied. Significant differences in the total lipid content were found between fish coming from the Rhine River and Lake Geneva (1.21 and 1.48%, respectively). Seasonal effects were investigated quarterly for perch sampled in the Rhine River. Intensively reared perch displayed a higher lipid content (1.48%) than the other farmed perch, i.e., 1.26% for a semiextensive system and 1.16% for an extensive system. No significant difference in lipid content was found (i) between lacustrine fish and intensively reared fish or (ii) among fish from the Rhine River and the semiextensive or extensive rearing systems. The main FA were 22∶6n−3 (DHA, 21.3–37.1% of total FA), 16∶0 (17.7–20.2%), 20∶5n−3 (EPA, 9.2–13.2%), 18∶1 (8.0–11.5%), 20∶4n−6 [arachidonic acid (ARA), 1.9–10.7%], 16∶1 (4.3–6.0%), and 18∶2n−6 (2.1–6.0%). In comparison with perch coming from the Rhine River, the lacustrine fish were characterized by higher total n−6 PUFA and a lower proportion of both total monounsaturated FA (MUFA) and total n−3 PUFA. Among rearing systems, extensively farmed fish had higher n−6 PUFA and lower n−3 PUFA contents. Wild fish showed higher ARA and 18∶2n−6 than farmed fish. They also had significantly more EPA (12.5–13.2%) than farmed perch (9.2–10.9%). For DHA no difference existed between (i) the lacustrine fish (31.9% of total FA) and the intensively reared fish (33.0%) and (ii) the Rhine (37.1%) and semiextensively reared fish (36%). Effects of size, diet composition, and environmental conditions on the total lipid contents and FA composition are discussed.
Fatty acid profiles and relative mobilization during fasting in adipose tissue depots of the American marten (Martes americana)
Authors: Nieminen Petteri , Rouvinen‐Watt Kirsti , Collins Danielle , Grant Judy , Mustonen Anne‐Mari
Published: February 2007

The American marten (Martes americana) is a boreal forest marten with low body adiposity but high metabolic rate. The study describes the FA composition in white adipose tissue depots of the species and the influence of food deprivation on them. American marten (n=8) were fasted for 2 d with 7 control animals. Fasting resulted in a 13.4% weight loss, while the relative fat mass was >25% lower in the fasted animals. The FA composition of the fat depots of the trunk was quite similar to other previously studied mustelids with 14∶0, 16∶0, 18∶0, 16∶1n−7, 18∶1n−9, and 18∶2n−6 as the most abundant FA. In the extremities, there were higher proportions of monounsaturated FA (MUFA) and PUFA. Food deprivation decreased the proportions of 16∶0 and 16∶1n−7, while the proportion of long‐chain MUFA increased in the trunk. The mobilization of FA was selective, as 16∶1n−7, 18∶1n−9, and particular n−3 PUFA were preferentially mobilized. Relative mobilization correlated negatively with the carbon chain length in saturated FA (SFA) and n−9 MUFA. The Δ9 desaturation of SFA enhanced the mobilization of the corresponding MUFA, but the positional isomerism of the first double bond did not correlate consistently with relative mobilization in MUFA or PUFA. In the marten, the FA composition of the extremities was highly resistant to fasting, and the tail tip and the paws contained more long‐chain PUFA to prevent the solidification of lipids and to maintain cell membrane fluidity during cooling.
Effects of conjugated linoleic acid and troglitazone on lipid accumulation and composition in lean and Zucker diabetic fatty (fa/fa) rats
Authors: Wendel Angela A. , Belury Martha A.
Published: February 2007

Dietary CLA has been shown to enhance glucose tolerance in several animal models, but in mice it induces insulin resistance and lipodystrophy. In this study, the effects of 2 wk of diet supplementation with either 1,5% CLA or 0.2% troglitazone (TZD), an insulin‐sensitizing thiazolidinedione, on glucose tolerance, lipid accumulation, and composition of both lean and Zucker diabetic fatty (fa/fa; ZDF) rats were examined. Compared with lean rats, which maintained normal glucose tolerances after 2 wk of feeding regardless of diet, ZDF rats fed a control diet (CON) had significantly worsened glucose tolerance. ZDF rats fed CLA and TZD diets, however, maintained normal glucose tolerances. In contrast to the significantly elevated lipid levels in ZDF rats fed the CON diet, concentrations of plasma FFA and TG in ZDF rats fed CLA and TZD diets were normalized. A similar reduction of plasma lipid levels was observed in lean rats fed CLA and TZD compared with lean rats fed the CON diet. Although ZDF CON rats developed significant hepatic steatosis, both CLA‐and TZD‐fed rats had hepatic TG levels similar to those of lean rats. Both lean and ZDF rats fed the CLA diet had reduced adipose mass compared with respective genotype controls; however, TZD had no effect. Ratios of 16∶1/16∶0 and 18∶1/18∶0 FA, surrogate markers for stearoyl‐CoA desaturase‐1 (SCD‐1) activity, were reduced in livers of ZDF rats fed CLA and TZD diets. These results show that, like TZD, CLA normalizes glucose tolerance and plasma lipids and also improves hepatic steatosis and FA composition in ZDF rats. The effects of CLA and TZD on hepatic lipid composition suggest that the effects of these two agents on glucose tolerance may be associated with a reduction in SCD‐1.
Olive oil consumption and weight change: The SUN prospective cohort study
Authors: Bes‐Rastrollo M. , Sánchez‐Villegas A. , de la Fuente C. , de Irala J. , Martínez J. A. , Martínez‐González M. A.
Published: February 2007

The aim of this dynamic prospective follow‐up study was to assess the association between olive oil consumption and the likelihood of weight gain or the incidence of overweight or obesity in a large Mediterranean cohort of 7,368 male and female Spanish university graduates (the SUN Project) who were followed for a median period of 28.5 mon. A validated Food Frequency Questionnaire was administered at baseline, and respondents also completed a follow‐up questionnaire after 28.5 mon. Changes in participants' consumption of olive oil and their weight were assessed during follow‐up. A higher baseline consumption of olive oil was associated with a lower likelihood of weight gain, although the differences were not statistically significant. The adjusted difference in weight gain (kg) was −0.16 [95% confidence interval (C1): −0.42 to +0.11] for participants in the upper quintile of olive oil consumption (median: 46 g/d) compared with those in the lowest quintile (median: 6 g/d). For participants with a high baseline consumption of olive oil whose olive oil consumption also increased during follow‐up, we found a slightly increased but nonsignificant risk of incidence of over‐weight or obesity (adjusted odds ratio=1.19, 95% C1: 0.73 to 1.95). Our study, carried out in a sample of free‐living people, shows that a high amount of olive oil consumption is not associated with higher weight gain or a significantly higher risk of developing overweight or obesity in the context of the Mediterranean food pattern.
Effects of soy or milk protein durign a high‐fat feeding challenge on oxidative stress, inflammation, and lipids in healthy men
Authors: Campbell Christina G. , Brown Blakely D. , Dufner Danielle , Thorland William G.
Published: February 2007

Soy isoflavones may impede atherogenic processes associated with cardiovascular disease. Research suggests that the postprandial generation of TG‐rich remnants contributes to the development of atherosclerosis. The purpose of the current study was to determine if 39 g soy (85 mg aglycone isoflavones, treatment) compared with 40 g milk protein (0 mg aglycone isoflavones, control) in combination with a high‐fat meal can modify postprandial, atherogenic‐associated events and biomarkers for oxidative stress, inflammation, and thrombosis. Fifteen healthy men (20–47 yr) participated in a double‐blind cross‐over meal‐challenge study occurring on two nonconsecutive days. The study meals consisted of two high‐fat apple muffins consumed with either a soy or milk shake (229 mL, 41% fat, 41% carbohydrate, and 18% protein). Blood samples were obtained at base‐line (fasted) and hours two, four, and six postprandial. Plasma TG significantly increased in both treatment and control meal challenges compared with baseline. There were no significant differences (P>0.05) between treatment (soy) and control (milk) for ex vivo copper‐induced LDL oxidation, serum C‐reactive protein, serum interleukin‐6 (IL‐6), serum fibrinogen, or plasma lipids (total cholesterol, HDL, LDL, TG). IL‐6‐concentrations significantly decreased as a function of time during either meal challenge (P=0.005). These data suggest that consumption of soy or milk protein in conjunction with a high‐fat meal does not acutely modify postprandial oxidative stress, inflammation, or plasma lipid concentrations in young, healthy men.
Oleate‐induced formation of fat cells with impaired insulin sensivitity
Authors: Xie Weisheng , Hamilton James A. , Kirkland James L. , Corkey Barbara E. , Guo Wen
Published: February 2007

Exogenous FA cause lipid accumulation in preadipocytes. We investigated whether the fat cells thus formed are metabolically distinct from adipocytes differentiated with standard methylisobutylxanthine, dexamethasone, and insulin (MDI) hormonal cocktail by comparing their expression of adipogenic genes, accumulation of TAG, lipogenesis, lipolysis, glucose uptake, and the effects of insulin on selected metabolic activities. Cells exposed to oleate began to accumulate TAG in parallel or prior to the induction of adipogenic genes, whereas cells treated with MDI expressed adipogenic genes before TAG accumulation. Oleate‐treated fat cells also showed exaggerated basal lipolysis and weak response to insulin in both lipolysis regulation and glucose uptake. These findings were associated with increased basal phosphorylation of perilipin, increased Glut‐1 but decreased Glut‐4 expression, and reduced insulin‐induced Akt phosphorylation. We suggest that this unique fat cell phenotype might be a mimetic of what can happen to fat cells formed in vivo under the influence of circulating FA and might be a useful model for in vitro studies of obesity‐related insulin resistance in adipocytes.
Coexistence of phosphatidylcholine‐specific phospholipase C and phospholipase D activities in rat cerebral cortex synaptosomes
Authors: Mateos Melina V. , Uranga Romina M. , Salvador Gabriela A. , Giusto Norma M.
Published: February 2007

DAG derived from phosphatidylcholine (PtdCho) acts as a lipid second messenger. It can be generated by the activation of phospholipase D (PLD) and the phosphatidic acid phosphohydrolase type 2 (PAP2) pathway or by a PtdCho‐specific phospholipase C (PtdCho‐PLC). Our purpose was to study PtdCho‐PLC activity in rat cerebral cortex synaptosomes (CC Syn). DAG production was highly stimulated by detergents such as Triton X‐100 and sodium deoxycholate. Ethanol and tricyclodecan‐9‐yl‐xanthate potassium salt decreased DAG generation by 42 and 61%, respectively, at 20 min of incubation. These data demonstrate that both the PLD/PAP2 pathway and PtdCho‐PLC contribute to DAG generation in CC Syn. PtdCho‐PLC activity remained located mainly in the synaptosomal plasma membrane fraction. Kinetic studies showedKmandVmaxvalues of 350 μM and 3.7 nmol DAG × (mg protein × h)−1, respectively. Western blot analysis with anti‐PtdCho‐PLC antibody showed a band of 66 KDa in CC Syn. Our results indicate the presence of a novel DAG‐generating pathway in CC Syn in addition to the known PLD/PAP2 pathway.
Diacylglycerol acyltransferase activity and triacylglycerol synthesis in germinating castor seed cotyledons
Authors: He Xiaohua , Chen Grace Q. , Lin Jiann‐Tsyh , McKeon Thomas A.
Published: February 2007

The central importance of storage lipid breakdown in providing carbon and energy during seed germination has been demonstrated by isolating the genes encoding the enzymes involved in FA β‐oxidation. In contrast, little is known about the ability of germinating seeds to synthesize TAG. We report that castor cotyledons are capable of TAG synthesis. The rate of incorporation of ricinoleic acid into TAG reached a peak at 7 d after imbibition (DAI) (1.14 nmol/h/mg) and decreased rapidly thereafter, but was sustained at 20 DAI in cotyledons and true leaves. The castor DAG acyltransferase (RcDGAT) mRNA and protein were expressed throughout seed germination at levels considerably enhanced from that in the dormant seed, thus indicating new expression. Significant degradation of the RcDGAT protein was observed after 7 DAI. The DGAT activity was found to be predominantly a function of the level of the intact RcDGAT protein, with the rate of TAG synthesis decreasing as degradation of the RcDGAT protein proceeded. A possible mechanism for the degradation of the RcDGAT protein is discussed. The induction of DGAT mRNA and protein, the capacity for TAG synthesis in vitro and in tissue slices, and the differing TAG composition of dormant seed TAG vs. cotyledonary TAG provide strong circumstantial evidence for active TAG synthesis by cotyledons. However, we have not yet determined the physiological significance of this capability.
Prediction of adipose tissue composition using raman spectroscopy: Average properties and individual fatty acids
Authors: Beattie J. Renwick , Bell Steven E. J. , Borgaard Claus , Fearon Ann , Moss Bruce W.
Published: February 2007

Raman spectroscopy has been used for the first time to predict the FA composition of unextracted adipose tissue of pork, beef, lamb, and chicken. It was found that the bulk unsaturation parameters could be predicted successfully [R2=0.97, root mean square error of prediction (RMSEP)=4.6% of 4 δ], with cis unsaturation, which accounted for the majority of the unsaturation, giving similar correlations. The combined abundance of all measured PUFA (≥2 double bonds per chain) was also well predicted with R2=0.97 and RMSEP=4.0% of 4 δ. Trans unsaturation was not as well modeled (R2=0.52, RMSEP=18% of 4 δ); this reduced prediction ability can be attributed to the low levels of trans FA found in adipose tissue (0.035 times the cis unsaturation level). For the individual FA, the average partial least squares (PLS) regression coefficient of the 18 most abundant FA (relative abundances ranging from 0.1 to 38.6% of the total FA content) was R2=0.73; the average RMSEP=11.9% of 4 δ. Regression coefficients and prediction errors for the five most abundant FA were all better than the average value (in some cases as low as RMSEP=4.7% of 4 δ). Cross‐correlation between the abundances of the minor FA and more abundant acids could be determined by principal component analysis methods, and the resulting groups of correlated compounds were also well predicted using PLS. The accuracy of the prediction of individual FA was at least as good as other spectroscopic methods, and the extremely straightforward sampling method meant that very rapid analysis of samples at ambient temperature was easily achieved. This work shows that Raman profiling of hundreds of samples per day is easily achievable with an automated sampling system.
Fluorescent image analysis of lipid hydroperoxides in fish muscle with 3‐perylene diphenylphosphine
Authors: Chotimarkorn Chatchawan , Ohshima Toshiaki , Ushio Hideki
Published: February 2007

A fluorescent image analysis method was developed to evaluate lipid hydroperoxide formation in fish muscle. The lipid hydroperoxides generated in white and dark fish muscles during storage at 5–6°C oxidized 3‐perylene diphenylphosphine located in the tissue to yield the fluorescent derivative, 3‐perylene diphenylphosphine oxide (3‐PeDPPO). 3‐PeDPPO thus obtained was determined by digital fluorescent image analysis. The 3‐PeDPPO fluorescence intensity of white and dark muscle increased during low‐temperature storage (0–24 h) and was clearly correlated with total lipid hydroperoxide levels in muscle extracts, which were determined by using HPLC based on a triphenylphosphine oxidation method (R2=0.954). These results suggest that 3‐PeDPPO fluorescence, coupled with fluorescent image analysis, is a novel tool for direct determination of lipid hydroperoxides in fish muscle without a need for extraction of lipid.
Acyl migration during debenzylation of 1,3‐di‐O‐benzyl‐2‐O‐acylglycerols
Authors: Yue Lijian , Zhang Chenggang , Zhang Guolin
Published: February 2007

In investigating the preparation of 2‐acylglycerol by debenzylation of 1,3‐di‐O‐benzyl‐2‐O‐acylglycerol, twelve 1,3‐di‐O‐benzyl‐2‐O‐acylglycerols were synthesized, 2‐O‐acyl moieties with one or more protons at the carbon atom adjacent to carbonyl group were found to migrate from C‐2 to C‐1 of the glycerol moiety during hydrogenation under Pd/C at room temperature.
Very long chain fatty acid methyl esters in transesterified palm oil
Authors: Puah Chiew Wei , Choo Yuen May , Ma Ah Ngan , Chuah Cheng Hock
Published: February 2007

Some unidentified minor compounds have been observed in the residue from short‐path distillation of transesterified palm oil that are not detected in the original palm oil. A method combining short‐path distillation to enrich the unknowns with fractionation using solid‐phase extraction is described. The fractionated components were identified using GC coupled with MS. The transesterified palm oil was found to contain methyl esters of up to C32 carbon atoms. In the very long chain FAME with carbon numbers ≥20, both even and odd carbon numbers accounted for 0.26 wt%, with C24 and C26 being the major ones present in the residue after short‐path distillation of transesterified palm oil.
Natural neo acids and neo alkanes: Their analogs and derivatives
Authors: Dembitsky Valery M.
Published: February 2007

This review presents more than 260 naturally occurring (as well as 47 synthesized) neo fatty (carboxylic) acids, neo alkanes, and their analogs and derivatives, isolated and identified from plants, algae, fungi, marine invertebrates, and microorganisms, that demonstrate different biological activities. These natural metabolites are good prospects for future chemical preparations as antioxidants, and also as anticancer, antimicrobial, and antibacterial agents. Described also are some synthetic bioactive compounds containing a tertiary butyl group(s) that have shown high anticancer, antifungal, and other activities. Applications of some neo fatty (carboxylic) acid derivatives in cosmetic, agronomic, and pharmaceutical industries also are considered. This is the first review to consider naturally occurring neo fatty (carboxylic) acids, neo alkanes, and other metabolites containing a tertiary butyl group(s) [or tert‐butyl unit(s)].
Gestational diabetes mellitus enhances arachidonic and docosahexaenoic acids in placental phospholipids
Authors: Bitsanis Demetris , Ghebremeskel Kebreab , Moodley Therishnee , Crawford Michael A. , Djahanbakhch Ovrang
Published: February 2007

In previous studies, we reported that neonates of women with gestational diabetes mellitus (GDM) have reduced blood levels of arachidonic acid (AA) and docosahexaenoic acid (DHA) that were unrelated to maternal status. Since both AA and DHA are selectively transferred from maternal to fetal circulation by the placenta, we have investigated whether the FA composition of the placenta is altered by GDM. Thirty‐six women, 11 with and 25 without GDM, were recruited from Newham General Hospital, London. The women with GDM had higher levels of di‐homo‐γ‐linolenic (P<0.05), docosate‐traenoic (n‐6 DTA; P<0.0001), docosapentaenoic n‐6 (P<0.005), total n‐6 (P<0.005), docosapentaenoic (n‐3 DPA; P<0.005), and total n‐3 (P<0.01) FA, as well as higher levels of AA (P<0.05) and DHA (P<0.01), in placental choline phosphoglycerides (CPG) compared with the healthy women who served as controls. Similarly, the women with GDM had elevated n‐6 DTA (P<0.005), AA, total n‐6 metabolites (P<0.05), DHA, total n‐3 metabolites, and total n‐3 FA (P<0.005) in ethanolamine phosphoglycerides (EPG). In contrast to CPG and EPG, the placental TG of the women with GDM had higher linoleic acid (P<0.05) and lower AA, n‐6 metabolites, and n‐3 DPA (P<0.01). The placenta is devoid of desaturase activity, and it is thought to be reliant on maternal circulation for both AA and DHA. Hence, the enhanced levels of the two FA in the placenta of the GDM group suggests that these FA are taken up from the maternal circulation and retained after esterification into phosphoglycerides instead of being transferred to the fetus. Further study is needed to elucidate the mechanism involved and the effect of the phenomenon on postnatal growth and development of the offspring.
Effect of diacylglycerol on the development of impaired glucose tolerance in sucrose‐fed rats
Authors: Meguro Shinichi , Osaki Noriko , Matsuo Noboru , Tokimitsu Ichiro
Published: February 2007

The effects of DAG oil and TAG oil on impaired glucose tolerance in rats that were fed a diet containing high levels of sucrose were compared. Male Wistar rats (8 wk old and 32 wk old) were fed either high‐sucrose (57.5% sucrose w/w) or control diets containing either 10% (w/w) DAG or TAG oil with a similar FA composition for 48 wk in 8‐wk‐old rats and for 24 wk in 32‐wk‐old rats. Plasma lipids, the size of the islets of Langerhans, and insulin, glucose, and adipocytokine levels were measured. An oral glucose tolerance test (OGTT) was carried out during the study period. For rats in both age groups that were fed a high‐sucrose diet, the DAG oil group had lower plasma glucose and insulin response in an OGTT, and lower homeostasis model assessment‐R levels, than the TAG oil group. Furthermore, in 8‐wk‐old rats that were fed a high‐sucrose diet, the DAG oil group accumulated less visceral fat and showed decreases of plasma adiponectin and suppressed increases of plasma insulin, leptin, and the size of islet of Langerhans compared with the TAG oil group. No difference in the OGTT was found between the DAG and TAG oil groups in either age group of rats fed a control diet. In conclusion, these results suggest that DAG oil ingestion prevents the high‐sucrose‐diet‐induced development of impaired glucose tolerance compared with TAG oil ingestion.
Rat adult offspring serum lipoproteins are altered by maternal consumption of a liquid diet
Authors: Pennington J. S. , Pennington S. N.
Published: February 2007

Palatable liquid diets for the administration of ethanol (EtOH) to animals have proven to be a major advance for the study of the effects of EtOH consumption under conditions of isocaloric nutrition of the control animals. Using a liquid diet, the original aim of the reported studies was to examine the effect of maternal EtOH consumption during pregnancy on the lipoprotein (Lp) profiles of the adult offspring measured by means of nuclear magnetic resonance spectroscopy. However, initial data suggested that compared to a maternal chow diet, the basal maternal liquid diet (without EtOH) had a significant effect on specific serum Lp of the adult offspring. The adult off‐spring of mothers who had consumed a basal liquid diet with‐out EtOH exhibited significant increases in their plasma triglycerides (TG) and cholesterol content compared to adult offspring whose mothers consumed a chow diet. Further, there were significant increases in the offspring's VLDL and low density Lp (LDL) subfractions' particle number, regardless of whether the maternal liquid diet was ad libitum‐fed, pair‐fed, or EtOH‐containing. The increase in offspring plasma TG was due to increases in specific VLDL subfraction particle numbers and not to increased TG content per particle. Similarly, the increase in plasma cholesterol was the result of elevated level of the very small LDL particles but not to an increased amount of cholesterol per LDL particle. These findings should be further examined in light of the widespread use of liquid diets in, research to administer EtOH, especially for studies of fetal alcohol syndrome.
Effect of low vitamin a status on fat deposition and fatty acid desaturation in beef cattle
Authors: Siebert B. D. , Kruk Z. A. , Davis J. , Pitchford W. S. , Harper G. S. , Bottema C. D. K.
Published: February 2007

A group of Angus beef cattle was removed from temperate pastures and fed a very low β‐carotene cereal‐based ration in a feedlot for over 300 d. Half the group was supplemented weekly with retinyl palmitate (at the rate of 60,000 IU vitamin A/100 live weight (LW)/day), sufficient to offset clinical vitamin A deficiency; the other half received no supplement. Blood was sampled from all animals at biweekly intervals to assess β‐carotene and vitamin A status. Adipose tissue was sampled by biopsy on three occasions throughout the experimental period and at slaughter to assess FA composition. Muscle was sampled at slaughter to determine the intramuscular fat content. The mean plasma concentration of β‐carotene of all animals fell from an initial value of 20.1 to 5.2 μg/mL at 14 d, to 1.4 μg/mL at 35 d, and to zero at 105 d. Mean vitamin A in plasma was not significantly different between the treatment groups initially. The values then rose to almost twice their initial values by 35 d, but subsequently fell to below initial values by day 119. Thereafter, plasma vitamin A of the supplemented group was significantly greater than that of the unsupplemented group (P<0.05). Muscle samples at slaughter from supplemented animals contained significantly (P<0.01) more intramuscular lipid (13.0 vs. 9.6%). Major changes occurred over time in FA composition in both groups. Saturated FA decreased as monounsaturated FA increased over the first 60 d. An index of desaturation of FA was significantly lower (P<0.001) in the vitamin A‐supplemented group than in the nonsupplemented group. M.P. of the adipose tissue of nonsupplemented animals was 32.3°C, significantly less (P<0.05) than that of supplemented animals (34.1°C). Feeding vitamin A was associated with less intramuscular fat but with a less desirable (less unsaturated, more solid) FA profile.
Differential effect of lysophospholipids on activities of human plasma paraoxonase1, either soluble or lipid‐bound
Authors: Park Cheon Ho , Nguyen Su Duy , Kim Mee Ree , Jeong Tae‐Sook , Sok Dai‐Eun
Published: February 2007

Interaction of paraoxonasel (PON1) with lysophospholipids was examined with respect to activity regulation and binding property. Paraoxonase activity of purified PON1 was partially inhibited by palmitoyl‐lysophosphatidylglycerol (palmitoyl‐lysoPG) and lysophosphatidylinositol (lysoPl), which had a stimulatory effect on arylesterase and diazoxonase activities. The selective inhibition of paraoxonase activity by palmitoyl‐lysoPG, characterized by noncompetitiveness and charge interaction, was also observed with HDL‐or dimyristoylphosphatidylcholine (DMPC)‐bound PON1. Mean‐while, lysophosphatidylcholine (lysoPC) stimulated all three activities of purified PON1, although it stimulated DMPC‐bound or HDL‐bound PON1 to a lesser extent. The stimulatory action of lysophospholipids was observed around their CMC, suggesting that micelle formation of lysophospholpids might be involved in the stimulation of PON1 activity. Presumably in support of this, the tryptophan fluorescence intensity of PON1 was increased by lysophospholipids at concentrations required for the stimulation of PON1 activity. Separately, lysoPC stimulation was less remarkable for DMPC‐bound PON1 than for either dimyristoylphosphatidylserine (DMPS)‐or dimyristoylphos‐phatidylglycerol‐bound PON1, suggesting a tight association between PON1 and DMPC. In support of this, the stimulatory role of apolipoprotein A‐I was less prominent for DMPC‐bound PON1 than for DMPS‐bound PON1. Taken together, these data suggest that the inhibition of paraoxonase activity by lysoPG or lysoPI may be due to binding to a site distinct from the active center, whereas the stimulation by lysophospholipid may be ascribed to the micelle formation around the lipid‐associable region of PON1.
Analysis of triacylglycerols of seeds and berries of sea buckthorn (Hippophaë rhamnoides) of different origins by mass spectrometry and tandem mass spectrometry
Authors: Yang Baoru , Kallio Heikki
Published: February 2007

TAG of seeds, berries, and fruit pulp/peel of different subspecies of sea buckthorn (Hippophaë rhamnoides) were analyzed by MS and tandem mass spectrometry (MS/MS). The seeds contained mainly TAG with acyl carbon number (ACN) of 52 with 2–6 double bonds (DB) (20–30%), and TAG of ACN 54 with 3–9 DB (70–80%). In the pulp/peel fraction, the major TAG were species with ACN:DB of 48∶1 to 48∶3 (19–49%), 50∶1 to 50∶4 (31–41%), and 52∶1 to 52∶6 (9–19%). The molecular weight species of whole berries largely resembled those of fruit pulp/peel with additional species of ACN 54 from the seeds (5–24%). Subspecies (spp.) sinensis differed from ssp. mongolica and rhamnoides by having a higher proportion of TAG of ACN 52 (27% vs. 21% and 22%, P<0.05) and a lower proportion of ACN 54 (71% vs. 79% and 78%, P<0.01) in seed TAG. Seed TAG of ssp. mongolica contained a higher proportion of more unsaturated species compared with those of the two other subspecies. Berry TAG of ssp. mongolica had the highest proportion of molecular species of ACN 48 due to the higher proportion of palmitic and palmitoleic acids and the lower seed content of the berries. Overall, palmitic acid favored the sn‐1 and sn‐3 positions. The order of preference of unsaturated FA for the sn‐2 position depended at least partially on the FA combination of TAG. Seed TAG of ssp. mongolica contained a higher proportion of α‐linolenic acid in the sn‐2 position than those of ssp. sinensis. In berry TAG, ssp. mongolica had the highest proportions of palmitoleic and linoleic acids in the sn‐2 position, and the lowest proportion of oleic/cis‐vaccenic acid in the sn‐2 position, among the three subspecies.
NMR characterization of dihydrosterculic acid and its methyl ester
Authors: Knothe Gerhard
Published: February 2007

Cyclopropane FA occur in nature in the phosphoplipids of bacterial membranes, in oils containing cyclopropene FA, and in Litchi sinensis oil. Dihydrosterculic acid (2‐octyl cyclopropaneoctanoic acid) and its methyl ester were selected for 1H and 13C NMR analysis as compounds representative of cyclopropane FA. The 500 MHz 1H NMR spectra acquired with CDCl3 as solvent show two individual peaks at −0.30 and 0.60 ppm for the methylene protons of the cyclopropane ring. Assignments were made with the aid of 2D correlations. In accordance with previous literature, the upfield signal is assigned to the cis proton and the downfield signal to the trans proton. This signal of the trans proton is resolved from the peak of the two methine protons of the cyclopropane ring, which is located at 0.68 ppm. The four protons attached to the two methylene carbons α to the cyclopropane ring also show a split signal. Two of these protons, one from each methylene moiety, display a distinct shift at 1.17 ppm, and the signal of the other two protons is observed at 1.40 ppm, within the broad methylene peak. The characteristic peaks in the 13C spectra are also assigned.
Effect of temperature on the fatty acid composition and temporal trajectories of fatty acids in fasting Daphnia pulex (Crustacea, cladocera)
Authors: Schlechtriem Christian , Arts M. T. , Zellmer I. D.
Published: February 2007

Poikilothermic organisms accumulate highly unsturated FA (HUFA) in their lipids at reduced temperatures to maintain cell membrane fluidity. In this study we investigated the effect of temperature on temporal trajectories of FA of fasting Daphnia pulex cultured on a HUFA‐free diet. Daphnia pulex populations were maintained for 1 mon at 22 and 11°C and were fed the chlorophyte Ankistrodesmus falcatus. We observed conversion of C18 FA precursors to EPA (20∶5n3) and arachidonic acid (ARA; 20∶4n6) in D. pulex. We showed that long‐term exposure to cold temperature causes a significant increase in EPA, HUFA such as ARA and EPA are highly conserved during starvation. Therefore, D. pulex has the biosynthetic capacity to adjust and to maintain the content of HUFA required to survive at low temperatures.
Effects of storage time and added antioxidant on fatty acid composition of red blood cells at −20°C
Authors: Magnusardottir Anna R. , Skuladottir Gudrun V.
Published: February 2007

The stability of PUFA in venous red blood cells (RBC) of women aged 25 to 55 years (n=12) was investigated during storage at −20°C. The RBC sample from each participant was divided into seven portions: one baseline with the antioxidant BHT, another without BHT, samples without BHT stored for 2, 4, 9, or 17 wk, and samples with BHT stored for 17 wk. No difference was found in proportions of PUFA at baseline and after storage for 2 and 4 wk without BHT, and 17 wk with BHT. After 9 wk without BHT the proportion of 22∶6n−3 in RBC was lower, and after 17 wk without BHT proportions of all PUFA were lower than at baseline. High proportion of 22∶6n−3 in RBC at baseline was associated with more stable concentration of total FA in RBC without BHT during 17 wk. The findings indicate that PUFA in RBC from healthy women are stable at −20°C for 4 wk, without BHT and for at least 17 wk with BHT.
Differential effects of modulation of docosahexaenoic acid content during development in specific regions of rat brain
Authors: Levant Beth , Ozias Marlies K. , Jones Karra A. , Carlson Susan E.
Published: February 2007

Variation in brain FA composition, particularly decreased DHA (22ŋ6n−3), affects neurodevelopment, altering visual, attentional, and cognitive functions, and is implicated in several neuropsychiatric disorders. To further understand how specific brain processes and systems are affected by variation in brain DHA content, we sought to determine whether specific brain regions were differentially affected by treatments that after brain DHA content. Adult male Long‐Evans rats were raised from conception using diet/breeding treatments to produce four groups with distinct brain phospholipid compositions. Total phospholipid FA composition was determined in whole brain and 15 brain regions by TLC/GC. Brain regions exhibited significantly different DHA contents, with the highest levels observed in the frontal cortex and the lowest in the substantia nigra/ventral tegmental area. Increased availability of DHA resulted in increased DHA content only in the olfactory bulb, parietal cortex, and substantia nigra/ventral tegmental area. In contrast, treatment that decreased whole‐brain DHA levels decreased DHA content in all brain regions except the thalamus, dorsal midbrain, and the substantia nigra/ventral tegmental area. Alterations in DHA level were accompanied by changes in docosapentaenoic acid (n−6 DPA, 22∶5n−6) content; however, the change in DHA and n−6 DPA was nonreciprocal in some brain regions. These findings demonstrate that the FA compositions of specific brain regions are differentially affected by variation in DHA availability during development. These differential effects may contribute to the specific neurochemical and behavioral effects observed in animals with variation in brain DHA content.
Dietary intakes and food sources of fatty acids for Belgian women, focused on n‐6 and n‐3 polyunsaturated fatty acids
Authors: Sioen Isabelle A. , Pynaert Hse , Matthys Christophe , De Backer Guy , Van Camp John , De Henauw Sterfaan
Published: February 2007

The intake of fat, saturated and monounsaturated FA (SFA and MUFA), and omega‐6 and omega‐3 PUFA has been estimated in 641 Belgian women (age 18‐39 y). Their food intake was recorded using a 2‐d food diary. The PUFA included were linoleic (LA), alpha‐linolenic (LNA), arachidonic (AA), eicosapentaeonoic (EPA), docosapentaenoic (DPA) and docosahexaenoic (DHA) acids. The mean total fat intake corresponded to 34.3% of total energy intake (E). The mean intake of the FA groups corresponded to 13.7%, 13.1%, and 6.0% of E, for SFA, MUFA, and PUFA, respectively. The mean intake of LA was 5.3% of E and of LNA was 0.6% of E, with a mean LA/LNA ratio of 8.7. The mean intake of AA was 0.03% of E. The mean intake of EPA, DPA, and DHA was 0.4%, 0.01%, and 0.06% of E, respectively. According to the Belgian recommendations, the total fat and SFA intake was too high for about three‐quarters of the population. The mean LA and overall n‐6 PUFA intake corresponded with the recommendation, with part of the population exceeding the upper level. Conversely, the population showed a large deficit for LNA and n‐3 PUFA. The major food source for LA and LNA was fats and oils, followed by cereal products. The main sources of long‐chain PUFA were fish and seafood, and meat, poultry, and eggs. From a public health perspective, it seems desirable to tackle the problem of low n‐3 PUFA intake.
Influence of dietary oil content and conjugated linoleic acid (CLA) on lipid metabolism enzyme activities and gene expression in tissues of atlantic salmon (Salmo salar L.)
Authors: Kennedy Sean R. , Leaver Michael J. , Campbell Patrick J. , Zheng Xiaozhong , Dick James R. , Tocher Douglas R.
Published: February 2007

The overall objective is to test the hypothesis that conjugated linoleic acid (CLA) has beneficial effects in Atlantic salmon as a result of affecting lipid and FA metabolism. The specific aims of the present study were to determine the effects of CLA on some key pathways of FA metabolism, including FA oxidation and highly unsaturated FA (HUFA) synthesis. Salmon smolts were fed diets containing two levels of fish oil (low, ∼17%, and high, ∼34%) containing three levels of CLA (a 1∶1 mixture of cis‐9,trans‐11 and trans‐10,cis‐12 at 0, 1, and 2% of diet) for 3 mon. The effects of dietary CLA on HUFA synthesis and β‐oxidation were measured, and the expression of key genes in the FA oxidation and HUFA synthesis pathways, and the potentially important transcription factors peroxisome proliferators activated receptors (PPAR), were determined in selected tissues. Liver HUFA synthesis and desaturase gene expression was increased by dietary CLA and decreased by high diatary oil content. Carnitine palmitoyltransferase‐I (CPT‐I) activity and gene expression were generally increased by CLA in muscle tissues although they were relatively unaffected by dietary oil content. In general CPT‐1 activity or gene expression was not correlated with β‐oxidation. Dietary CLA tended to increase PPARα and β gene expression in both liver and muscle tissues, and PPARγ in liver. In summary, gene expression and activity of the FA pathways were altered in response to dietary CLA and/or oil content, with data suggesting that PPAR are also regulated in response to CLA. Correlations were observed between dietary CLA, liver HUFA synthesis and desaturase gene expression, and liver PPARα expression, and also between dietary CLA, CPT‐I expression and activity, and PPARα expression in muscle tissues. In conclusion, this study suggests that dietary CLA has effects on FA metabolism in Atlantic salmon and on PPAR transcription factors. However, further work is required to assess the potential of CLA as a dietary supplement, and the role of PPAR in the regulation of lipid metabolism in fish.
Conjugated linoleic acid and chromium lower body weight and visceral fat mass in high‐fat‐diet‐fed mice
Authors: Bhattacharya Arunabh , Rahman M. Mizanur , McCarter Roger , O'Shea Marianne , Fernandes Gabriel
Published: February 2007

More than half of the U.S. population has a body mass index of 25 kg/m2or more, which classifies them as overweight or obese. Obesity is often associated with comorbidities such as diabetes, cardiovascular diseases, and cancer. CLA and chromium have emerged as major dietary supplements that reduce body weight and fat mass, and increase basal metabolic rate in animal models. However, studies show that CLA induces insulin resistance in mice and in humans, whereas Cr improves insulin sensitivity. Hence, we designed the present study to examine the combined effect of CLA and Cr on body composition and insulin sensitivity in a Balb/c mice (n=10/group) model of high‐fat‐diet‐induced obesity. CLA alone lowered body weight, total body fat mass, and visceral fat mass, the last of which decreased further with the combination of CLA and Cr. This effect was accompanied by decreased serum leptin levels in CLA‐fed and CLA+Cr‐fed mice, and by higher energy expenditure (EE) and oxygen consumption (OC) in CLA+Cr‐fed mice. Serum levels of glucose, insulin, the pro‐inflammatory cytokines, tumor necrosis factor‐α (TNF‐α), and interleukin‐6 (IL‐6), as well as insulin resistance index (IRI), decreased with CLA, whereas CLA and Cr in combination had significant effects on insulin and IL‐6 concentrations and IRI. In summary, CLA+Cr decreased body weight and fat mass in high‐fat‐diet‐fed mice, which may be associated with decreased leptin levels and higher EE and OC.
Effect of species and genotype on the efficiency of enrichment of poultry meat with n−3 polyunsaturated fatty acids
Authors: Rymer C. , Givens D. I.
Published: February 2007

The effect of poultry species (broiler or turkey) and genotype (Wrolstad or BUT T8 turkeys and Ross 308 or Cobb 500 broilers) on the efficiency with which dietary long‐chain n−3 PUFA were incorporated into poultry meat was determined. Broilers and turkeys of both genotypes were fed one of six diets varying in FA composition (two replicates per genotype x diet interaction). Diets contained 50 g/kg added oil, which was either blended vegetable oil (control), orpartially replaced with linseed oil (20 or 40 g/kg diet), fish oil (20 or 40 g/kg diet), or a mixture of the two (20 g linseed oil and 20 g fish oil/kg diet). Feeds and samples of skinless breast and thigh meat were analyzed for FA. Worlstad dark meat was slightly more responsive than BUT T8 (P=0.046) to increased dietary 18∶3 concentrations (slopes of 0.570 and 0.465, respectively). The Ross 308 was also slightly more responsive than the Cobb 500 (P=0.002) in this parameter (slopes of 0.557 and 0.449). There were no other significant differences between the genotypes. There was some evidence (based on the estimates of the slopes and their associated standard errors) that white turkey meat was more responsive than white chicken meat to 20∶5 (slopes of 0.504 and 0.289 for turkeys and broilers, respectively). There was no relationship between dietary 18∶3 n−3 content and meat 20∶5 and 22∶6 contents. If birds do convert 18∶3 to higher FA, these acids are not then deposited in the edible tissues.
Dose‐response impact of various tocotrienols on serum lipid parameters in 5‐week‐old female chickens
Authors: Yu Suzanne G. , Thomas Ann M. , Gapor Abdul , Tan Barrie , Qureshi Nilofer , Qureshi Asaf A.
Published: February 2007

The cholesterol‐suppressive action of the tocotrienol‐rich‐fraction (TRF) of palm oil may be due to the effect of its constituent tocotrienols on β‐hydroxy‐β‐methylglutaryl coenzyme A (HMG‐CoA) reductase activity. The tocotrienols modulate HMG‐CoA reductase activity via a post‐transcriptional mechanism. As a consequence small doses (5–200 ppm) of TRF‐supplemented diets fed to experimental animals lower serum cholesterol levels. These findings led us to evaluate the safety and efficacy of large supplements of TRF and its constituents. Diets supplemented with 50, 100, 250, 500, 1,000, or 2,000 ppm of TRF, α‐tocopherol, α‐tocotrienol, γ‐tocotrienol, or δ‐tocotrienol were fed to chickens for 4 wk. There were no differences between groups or within groups in weight gain, or in feed consumption at the termination of the feeding period. Supplemental TRF produced a dose‐response (50–2,000 ppm) lowering of serum total and LDL cholesterol levels of 22% and 52% (P<0.05), respectively, compared with the control group. α‐Tocopherol did not affect total or LDL‐cholesterol levels. Supplemental α‐tocotrienol within the 50–500 ppm range produced a dose‐response lowering of total (17%) and LDL (33%) cholesterol levels. The more potent γ and δ isomers yielded dose‐response (50–2,000 ppm) reductions of serum total (32%) and LDL (66%) cholesterol levels. HDL cholesterol levels were minimally impacted by the tocotrienols; as a result, the HDL/LDL cholesterol ratios were markedly improved (123–150%) by the supplements. Serum triglyceride levels were significantly lower in sera of pullets receiving the higher supplements. The safe dose of various tocotrienols for human consumption might be 200–1,000 mg/d based on this study.
Influence of diet on fatty acids and tocopherols in M. Longissimus Dorsi from reindeer
Authors: Sampels S. , Wiklund E. , Pickova J.
Published: February 2007

Our aim was to compare the effects of two pelleted diets containing differing FA composition with natural lichen pasture on reindeer's meat FA composition. In addition we wanted to increase the knowledge about reindeer FA metabolism and the effect of animal sex and age on FA composition in reindeer muscle.

The trial included five reindeer groups: three grazing, consisting of adult males, adult females, and calves; and two groups of calves fed conventional pellets (CPD) and pellets containing crushed linseed (LPD), respectively, for two months before slaughter. Differences between male and female animals were mainly found in the neutral lipid fraction and related to fatness. Calves differed significantly from adult males and females in FA and lipid class composition. CPD led to a higher ratio of n−6 to n−3 FA compared with grazing. The ratio n−6/n−3 in the polar lipid (PL) fraction of the animals fed LPD was slightly, but not significantly, higher than that in the grazing reindeer. LPD‐fed animals had lower proportions of long‐chain polyunsaturated FA (LCPUFA), namely 20∶4n−6, 22∶5n−3, and 22∶6n−3, in the PL fraction compared with the grazing animals due to the content of these FA in the natural feed. The animals seemed unable to elongate dietary FA in significant amounts. We conclude that by adding crushed linseed to the pellets it was possible to keep the favorable FA composition of meat from grazing reindeer with regard to the n−6/n−3 ratio but not in LCPUFA.