bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conjugated linoleic acid reduces hepatic steatosis, improves liver function, and favorably modifies lipid metabolism in obese insulin‐resistant rats
Authors: Noto Amy , Zahradka Peter , Yurkova Natalia , Xie Xueping , Nitschmann Evan , Ogborn Malcolm , Taylor Carla G. 
Published: February 2007

AbstractCLA has been shown to induce or suppress excess liver lipid accumulation in various animal models. Interestingly, the state of insulin resistance may be an important modulator of this effect. The objective of the current study was to determine how feeding a dietary CLA mixture would affect liver lipid accumulation in insulin‐resistant/obese and lean rats in relation to liver function, lipidemia, liver TAG and phospholipid FA composition, and expression of hepatic markers of FA transport, oxidation, and synthesis. Six‐week‐old fa/fa and lean Zucker rats (n=20/genotype) were fed either a 1.5% CLA mixture or a control diet for 8 wk. CLA supplementation reduced liver lipid concentration of fa/fa rats by 62% in concurrence with improved liver function (lower serum alanine aminotransferase and alkaline phosphatase) and favorable modification of the serum lipoprotein profile (reduced VLDL and LDL and elevated HDL) compared with control‐fed fa/fa rats. The fa/fa genotype had two‐thirds the amount of CLA (as % total FA) incorporated into liver TAG and phospholipids compared with the lean genotype. In both genotypes, CLA altered the hepatic FA profile (TAG greater than phospholipids) and these changes were explained by a desaturase enzyme index. Liver‐FA‐binding protein and acyl CoA oxidase, markers of FA transport and oxidation, respectively, were expressed at higher levels in CLA‐fed fa/fa rats. In summary, these results illustrate a strong relationship between the state of insulin resistance and liver lipid metabolism and suggest that CLA acts to favorably modify lipid metabolism in fa/fa Zucker rats.
Selective incorporation of docosahexaenoic acid into lysobisphosphatidic acid in cultured THP‐1 macrophages
Authors: Besson Nelly , Hullin‐Matsuda Francoise , Makino Asami , Murate Motohide , Lagarde Michel , Pageaux Jean‐Francois , Kobayashi Toshihide , Delton‐Vandenbroucke Isabelle 
Published: February 2007

AbstractLysobisphosphatidic acid (LBPA) is highly accumulated in specific domains of the late endosome and is involve in the biogenesis and function of this organelle. Little is known about the biosynthesis and metabolism of this lipid. We examined its FA composition and the incorporation of exogenous FA into LBPA in the human monocytic leukemia cell line THP‐1. The LBPA FA composition in THP‐1 cells exhibits an elevated amount of oleic acid (18∶1n−9) and enerichment of PUFA, especially DHA (22∶6n−3). DHA supplemented to the medium was efficiently incorporated into LBPA. In contrast, arachidonic acid (20∶4n−6) was hardly esterified to LBPA under the same experimental conditions. The turnover of DHA in LBPA was similar to that in other phospholipids. Specific incorporation of DHA into LBPA was also observed in baby hamster kidney fibroblasts, although LBPA in these cells contains very low endogenous levels of DHA in normal growth conditions. Our results, together with published observations, suggest that the specific incorporation of DHA into LBPA is a common phenomenon in mammalian cells. The physiological significance of DHA‐enriched LBPA is discussed.
Characterization of hair lipid images by argon sputter etching‐scanning electron microscopy
Authors: Masukawa Yoshinori , Tanamachi Hiroto , Tsujimura Hisashi , Mamada Akira , Imokawa Genji 
Published: February 2007

AbstractHair lipid images, as visualized by argon sputter etching‐scanning electron microscopy (ASE‐SEM), reveal convex structures with a stitch pattern (SP) at the cell membrane complex (CMC) in the transverse hair plane. Based on interindividual variation, different features of the convex SP were classified into Types 0 to 4 with the corresponding scores 0 to 4. Observations using hair fibers collected from 27 Japanese females revealed significant positive correlations between the scores and the levels of exogenous lipids, which suggests that exogenous lipids internalized at the CMC predominantly constitute the convex SP. Intraindividual variation with different levels of exogenous lipids among hair fibers derived from individual females may be relevant to the uneven physicochemical properties of hair fibers on the scalp. Observations of 380 hair fibers collected from Japanese (Mongoloid), German and American (Caucasoid) females aged 3 to 77 yr demonstrated similar age‐related changes in the lipid images, which represent an increase and then a decrease in levels of exogenous lipids with increasing age. This suggests that age‐related changes in exogenous lipids are attributable to alterations in sebum excreted during aging and that this elicits age‐related changes in physical parameters, which affect human hair texture.
Lower weight gain and higher expression and blood levels of adiponectin in rats fed medium‐chain TAG compared with long‐chain TAG
Authors: Takeuchi Hiroyuki , Noguchi Osamu , Sekine Seiji , Kobayashi Aiko , Aoyama Toshiaki 
Published: February 2007

AbstractPrevious studies demonstrated that, compared with long‐chain TAG (LCT), dietary medium‐chain TAG (MCT) could improve glucose tolerance in rats and humans. It has been well established that adiponectin acts to increase insulin sensitivity. The effects of dietary MCT on adiponectin serum concentration and mRNA levels in adipose tissue were studied in rats. Male Spague‐Dawley rats were feda diet containing 20% MCT or LCT for 8 wk. After 6 wk of dietary treatment, an oral glucose tolerance test was performed. Rats fed the MCT diet had less body fat accumulation than those fed the LCT diet (P<0.01). The cell diameter of the perirenal adipose tissue, one of the abdominal adipose tissues, was smaller (P<0.01) in the MCT diet group. The serum adiponectin concentration was higher (P<0.01) in the MCT diet group than in the LCT diet group. The adiponectin content in the perirenal adipose tissue was higher (P<0.01) in the MCT diet group. The MCT‐fed group had a higher adiponectin mRNA level in their perirenal adipose tissue (P<0.05). The increase of the plasma glucose concentration after glucose administration istration (area under the curve) was smaller (P<0.01) in the MCT diet group than in the LCT diet group. These findings suggest that dietary MCT, compared with LCT, results in a higher serum adiponectin level with trascriptional activation of the adiponectin gene in rats. We speculate that improved lucose tolerance in rats fed an MCT diet may be, at least in part, ascribed to this higher serum adiponectin level.
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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractDietary 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

AbstractThe 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

AbstractSoy 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

AbstractExogenous 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

AbstractDAG 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

AbstractThe 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

AbstractRaman 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.