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21.
Influence of Serum and Hypoxia on Incorporation of [14C]-d-Glucose or [14C]-l-Glutamine into Lipids and Lactate in Murine Glioblastoma Cells
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Glucose and glutamine are essential energy metabolites for brain tumor growth and survival under both normoxic and hypoxic conditions. Both metabolites can contribute their carbons to lipid biosynthesis. We used uniformly labeled [14C]‐U‐d ‐glucose and [14C]‐U‐l ‐glutamine to examine the profile of de novo lipid biosynthesis in the VM‐M3 murine glioblastoma cells. The major lipids synthesized included phosphatidylcholine (PtdCho), phosphatidylethanolamine (EtnGpl), phosphatidylinositol (PtdIns), phosphatidylserine (PtdSer), sphingomyelin (CerP Cho), bis(monoacylglycero)phosphate (BMP)/phosphatidic acid (PtdOH), cholesterol (C), cardiolipin (Ptd2Gro), and gangliosides. Endogenous lipid synthesis, using either glucose or glutamine, was greater in media without fetal bovine serum (FBS) than in media containing 10 % FBS under normoxia. De novo lipid synthesis was greater using glucose carbons than glutamine carbons under normoxia. The reverse was observed for most lipids under hypoxia suggesting an attenuation of glucose entering the TCA cycle. Lactate was produced largely from glucose carbons with minimal lactate derived from glutamine under either normoxia or hypoxia. Accumulation of triacylglycerols (TAG), containing mostly saturated and mono‐unsaturated fatty acids, was observed under hypoxia using carbons from either glucose or glutamine. The data show that the incorporation of labeled glucose and glutamine into most synthesized lipids was dependent on the type of growth environment, and that the VM‐M3 glioblastoma cells could acquire lipids, especially cholesterol, from the external environment for growth and proliferation. 相似文献
22.
A three-stage route to chemically upcycle post-consumer poly(ethylene terephthalate) (PET) to produce high compressive strength composites is reported. This procedure involves initial glycolysis with diethylene glycol to produce a mixture (GPET) comprising oligomers of 2–7 terephthalate units followed by trans/esterification of GPET with fatty acid chains supplied by brown grease, an agricultural by-product of animal fat of relatively low nutritional or fuel value. This process yields PGB comprising a mixture of mono-terephthalate ester derivatives. The olefin units provided by unsaturated fatty acid chains in brown grease were crosslinked by an inverse vulcanization reaction with elemental sulfur to give composites GBSx (x = wt% S, varied from 80%–90%). The compressive strengths of GBS80 (27.5 ± 2.6 MPa) and GBS90 (19.2 ± 0.8 MPa) exceed the compressive strength required of ordinary Portland cement (17 MPa) for its use in residential building foundations. The current route represents a way to repurpose waste plastic, energy sector by-product sulfur, and agricultural by-product brown grease to give high strength composites with mechanical properties suggesting their possible use to replace less sustainably sourced legacy structural materials. 相似文献
23.
关于甘三酯中脂肪酸分布的假说很多,各种假说都只是在一定范围内对一类或几类油脂具有使用意义,对于其它类油脂则没有通用性。R—分布仅用于低芥酸菜油,利用它可直接由其脂肪酸组成计算甘三酯中脂肪酸的分布及甘三酯的组分,并证实对于低芥酸菜油,R—分布比其它类似分布假设具有更好的准确性。国内低芥酸品种正处在发展阶段,R—分布能有效地应用于国产低芥酸菜油,为快速了解其甘三酯结构的信息提供了一条方便的途径,从而代替了复杂的胰脂酶水解的分析过程,这不仅具有一定的理论意义,而且也有一定的经济价值。 相似文献
24.
《分离科学与技术》2012,47(11):1636-1647
In the present study, attempts were made to examine the filtration behavior of organic mixtures (oleic acid-triglycerides) compared to single organic solute (triglycerides) contained in synthetic glycerol-water solutions (known as sweetwater). Furthermore, the rejections of individual solutes were studied. The TG-FA mixtures permeated preferentially when compared with single TG which is mainly due to the solubility as well as diffusivity of small fatty acid in the TG-FA mixtures. Furthermore, PVDF membrane provided higher fluxes and experienced less fouling than PES membrane for both cases. In case of the PVDF membrane the rejection of fatty acid was 6.20% while oil rejection in glycerol-water plus TG and TG-FA mixtures was 82.42% and 84.67%, respectively. However, the PES membrane underwent higher fatty acid rejection (20.93%) as well as oil rejection in single TG (94.70%) and TG-FA mixtures (91.08%). It is noteworthy that the nature of the membrane, membrane MWCO, and the feed characteristics had a significant effect on the fouling potential and filtration performance. 相似文献
25.
Lard and high-oleic sunflower oil (Trisun® Extra) were interesterified at 55°C for 24 h with SP435 lipase from Candida antarctica to produce plastic fats. As the amount of trisun increased, percentage free fatty acid, unsaturated fatty acid/saturated fatty acid value, oxidizability, and the amount of 18:1 found at the sn-2 position of triglyceride products increased. Differential scanning calorimetry showed that the low-melting components in the product contained more 18:1 than the high-melting components. A 60:40 (w/w) ratio of lard to trisun had the widest plastic range (3–26°C). The scaled-up reaction to produce this blend resulted in a product that had 60.1% 18:1 at the sn-2 position compared to 44.9% for the physical blend. The solid fat content of the 60:40 interesterified mixture resembled soft-type margarine oil. 相似文献
26.
Yi-Jen Fang Chih-Hsien Chiu Yuan-Yen Chang Chung-Hsi Chou Hui-Wen Lin Ming-Feng Chen Yi-Chen Chen 《Food research international (Ottawa, Ont.)》2011,44(9):3105-3110
Chronic alcohol consumption or alcohol abuse is the main cause of alcoholic steatohepatitis or further cirrhosis. This study was to exam if the antioxidant capacity and alcohol metabolism in livers of chronic alcohol-fed rats were improved by supplementing taurine (Tau). Rats were randomly divided into four groups with five times per week of treatment: 1) isocaloric solution; 2) 3 g alcohol/kg BW/day; 3) 3 g alcohol/kg BW/day + 1 g taurine (Tau)/kg BW/day; and 4) 3 g alcohol/kg BW/day + 2 g Tau/kg BW/day. A 6-week alcohol consumption resulted in lower (p < 0.05) body weight gain and self-antioxidant capacities, as well as increased (p < 0.05) liver size, serum/hepatic lipids, and AST and ALT values. However, alcohol-fed rats co-treated with Tau have decreased (p < 0.05) liver lipid levels via increasing fecal lipid output and cholesterol metabolism. Besides, co-treatment of Tau also enhanced (p < 0.05) self-antioxidant capacities and alcohol metabolism in livers via enhancing GSH contents, CAT, GSH-Px, ADH, and ALDH activities, but decreasing MDA contents. In a histological examination of rat liver, microvesicular steatosis and necrotic cells were observed in alcohol-fed rats without Tau while largely suppressed microvesicular steatosis and no necrotic cells were observed in alcohol-fed rat supplemented with Tau. Therefore, Tau could be an effective hepatoprotective agent against alcohol-induced damage via enhancing self-antioxidant capacity and alcohol metabolism. 相似文献
27.
Loss of Fat with Increased Adipose Triglyceride Lipase-Mediated Lipolysis in Adipose Tissue During Laying Stages in Quail 总被引:1,自引:0,他引:1
The goal of the current study was to investigate regulation of key genes involved in lipid metabolism in adipose and liver to relate lipolytic and lipogenic capacities with physiological changes at the pre-laying, onset of laying, and actively laying stages of quail. Followed by a 50 % increase from pre-laying to onset of laying, adipose to body weight ratio was significantly reduced by 60 % from the onset of laying to the actively laying stage (P < 0.05), mainly resulting from the significantly increased adipocyte size from the pre-laying stage to the onset of laying and reduction of adipocyte size from the onset of laying to the actively laying stage (P < 0.05). In the adipose tissue of actively laying quail, increased protein expression and phosphorylation of adipose triglyceride lipase (ATGL) together with an elevated mRNA expression of comparative gene identification-58, an activator of ATGL, contributes to increased lipolytic activity, as proved by increased amounts of plasma non-esterified fatty acid (P < 0.05). In addition, decreased mRNA expression of fatty acid transport protein in the actively laying quail could contribute to the adipocyte hypotrophy (P < 0.05). In the liver, relative mRNA expression of apo-very low density lipoprotein (VLDL)-II increased significantly from the pre-laying to actively laying stages (P < 0.05), indicating increased apoVLDL-II actively facilitated VLDL secretion in the actively laying quail. These results suggest that the laying birds undergo active lipolysis in the adipocyte, and increase VLDL secretion from the liver in order to secure a lipid supply for yolk maturation. 相似文献
28.
Wei X Wang D Yang Y Xia M Li D Li G Zhu Y Xiao Y Ling W 《Journal of the science of food and agriculture》2011,91(6):1006-1013
BACKGROUND: Cyanidin‐3‐O‐β‐glucoside (Cy‐3‐g)‐rich foods have been reported to inhibit the onset of obesity, but whether the pure anthocyanin supplementation affects obesity remains uncertain. RESULTS: Cy‐3‐g supplementation significantly reduced obesity, accumulation of fat in visceral adipose and liver tissues, and plasma triglyceride levels. Furthermore, adenosine monophosphate (AMP)‐activated protein kinase phosphorylation (pAMPK) in the skeletal muscle and visceral adipose were significantly increased by Cy‐3‐g consumption. This was followed by the activation of lipoprotein lipase (LPL) in plasma and skeletal muscle but the suppression of this enzyme in visceral adipose. LPL activation in skeletal muscle cells and its suppression in adipocytes by Cy‐3‐g were blocked by inhibition of pAMPK. CONCLUSION: Our present data thus demonstrate that Cy‐3‐g improves obesity and triglyceride metabolism in KK‐Ay mice. The underlying mechanism is found to be partly related to the activation of LPL in plasma and skeletal muscle, and inhibition of LPL in adipose tissue following the activation of pAMPK. Copyright © 2011 Society of Chemical Industry 相似文献
29.
Isolation and characterization of polymers in heated olestra and an olestra/triglyceride blend 总被引:2,自引:0,他引:2
Dale R. Gardner Robert A. Sanders 《Journal of the American Oil Chemists' Society》1990,67(11):788-796
High molecular weight components in thermally oxidized olestra (formerly called sucrose polyesters) and a mixture of olestra
and soybean oil were characterized. The high molecular weight components of these oils were separated by preparative size
exclusion chromatography and analyzed intact by mass spectrometry, infrared, and nuclear magnetic resonance spectroscopy.
The materials isolated from the heated olestra were identified as olestra polymers. Materials isolated from the heated mixed
oil (olestra and soybean oil) were identified as polymers of olestra and copolymers of olestra and triglycerides. Polymer
linkages identified were identical to those resulting from thermal oxidation of natural vegetable oils of similar fatty acid
composition. 相似文献
30.
为解决油茶籽油掺伪其他植物油的定性鉴别问题,在油茶籽油中分别掺入大豆油、花生油、葵花籽油、棉籽油、葡萄籽油、菜籽油、棕榈油和米糠油,设置高和低两种不同掺伪梯度,基于14个特征性脂肪酸和甘油三酯指标,运用Python语言构建并对比分析了二分类决策树模型、多分类决策树模型和多层感知机人工神经网络(MLP-ANN)模型用于油茶籽油掺伪定性鉴别的效果。结果表明:高和低掺伪梯度下,二分类决策树模型对油茶籽油掺伪其他植物油的定性鉴别的准确率均达到0.95以上;多分类决策树模型的精确率和准确率在高掺伪梯度下均达到了0.95,但在低掺伪梯度下仅为0.90;在高和低掺伪梯度下,MLP-ANN模型对油茶籽油掺伪定性鉴别的平均精确率均达到0.98,准确率分别达到0.97和0.98。相比于决策树模型,MLP-ANN模型能很好地实现油茶籽油掺伪定性鉴别。 相似文献