To see the other types of publications on this topic, follow the link: Triacylglycerols.
Journal articles on the topic 'Triacylglycerols'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Triacylglycerols.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Osagie, Anthony U., and Maureen E. Bafor. "Triacylglycerols of oil palm (Elaeis guineensis var. dura) mesocarp during fruit maturation." Biochemistry and Cell Biology 68, no. 1 (January 1, 1990): 313–17. http://dx.doi.org/10.1139/o90-043.
Full textAbstract:
Changes in triacylglycerol pattern in the mesocarp of developing oil palm fruit were studied. The triacylglycerols were isolated by thin-layer chromatography of the neutral lipid fraction on silica gel plates and further resolved by argentation chromatography. The component fatty acids of individual triacylglycerols were analysed and particular distributions and changes were noted. The triacylglycerol content increased with mesocarp age, accounting for over 90% of the mature mesocarp neutral lipids. The immature fruit mesocarp triacylglycerols contained predominantly saturated fatty acids, whereas the major fatty acid component of the mature fruit mesocarp triacylglycerols was monounsaturated. Only one species of triacylglycerol was present in the mesocarp during the first 14 weeks after anthesis. Three triacylglycerol species were present at 16 weeks after anthesis, whereas six triacylglycerol species were identified from 17 weeks on.Key words: Elaeis guineensis, oil palm mesocarp, triacylglycerols, fatty acids, maturation.
2
Chen, Z. Y., and S. C. Cunnane. "Preferential retention of linoleic acid-enriched triacylglycerols in liver and serum during fasting." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 263, no. 2 (August 1, 1992): R233—R239. http://dx.doi.org/10.1152/ajpregu.1992.263.2.r233.
Full textAbstract:
Fasting has been reported to quantitatively increase linoleic and arachidonic acids in liver triacylglycerols, but the origin and mechanism of this change are unknown. The changes in long-chain fatty acids and triacylglycerol species of liver, serum, adipose tissue, and heart were therefore examined during a period of 24- or 48-h fasting in the rat. In liver and serum triacylglycerols, fasting resulted in a quantitative increase in arachidonic, stearic, linoleic, alpha-linolenic, and docosahexaenoic acids but a decrease in oleic, palmitic, and palmitoleic acids. After fasting, oleic acid was depleted the most from liver and serum triacylglycerols followed by palmitoleic and palmitic acids. Triacylglycerol species containing palmitic, palmitoleic, and oleic acids were depleted the most from liver and serum during fasting. Linoleic acid-enriched triacylglycerol species were proportionally and, in some cases, quantitatively increased in liver and serum triacylglycerols during fasting. Net retention of triacylglycerol species with a total acyl carbon number of 56 or 58 in the liver and 60 in serum was also observed during fasting. Selective retention of triacylglycerol species did not occur in the heart or perirenal or epididymal adipose tissue during fasting. Tissue phospholipid fatty acids were largely unaffected by fasting. Our data suggest that during fasting, long-chain fatty acids released from adipose tissue are differentially utilized and hepatic triacylglycerol species are remodeled, permitting optimal tissue composition of essential fatty acids, particularly linoleic acid.
3
Calder, P. C., P. Yaqoob, and E. A. Newsholme. "Triacylglycerol metabolism by lymphocytes and the effect of triacylglycerols on lymphocyte proliferation." Biochemical Journal 298, no. 3 (March 15, 1994): 605–11. http://dx.doi.org/10.1042/bj2980605.
Full textAbstract:
This study investigates the ability of lymphocytes to utilize fatty acids originating from triacylglycerols and the effect of triacylglycerols upon mitogen-stimulated lymphocyte proliferation. Lymphocytes isolated from rat lymph nodes, spleen, thymus and lymphatic duct had a lipoprotein lipase activity of approx. 10 units/mg of protein, indicating that the fatty acids of circulating triacylglycerols are accessible to these cells. In culture lymph node lymphocytes hydrolysed triacylglycerols added to the medium as emulsions. Both non-esterified fatty acids and free glycerol appeared in the cell culture medium, but their concentrations indicated that a high proportion of each (65-90% of fatty acids and 60-80% of glycerol) was taken up by the cells. The incorporation and fate of triacylglycerol-fatty acids was studied by culturing the cells in the presence of tri[3H]oleoylglycerol or tri[14C]inoleoylglycerol. Both fatty acids were incorporated into lymphocyte lipids in a time-dependent manner; linoleic acid was incorporated at a significantly greater rate than oleic acid. The majority of oleic acid (greater than 70%) was incorporated into cellular triacylglycerol, while less than 10% was incorporated into phospholipids. In contrast, linoleic acid incorporation into cellular triacylglycerol never exceeded 25%, while up to 45% was incorporated into phospholipids. Triacylglycerols containing polyunsaturated fatty acids inhibited concanavalin A-stimulated lymphocyte proliferation in a concentration- and time-dependent manner; triacylglycerols containing saturated fatty acids or oleic acid were not inhibitory. Such direct effects of certain triacylglycerols on lymphocyte function may explain why some clinical trials of polyunsaturated fatty acid-rich diets have been successful in improving the condition of patients suffering from inflammatory diseases.
4
Yakimovich, I. Yu, D. A. Borodin, I. K. Podrezov, V. V. Ivanov, V. N. Vasiliyev, and M. Yu Kotlovsky. "EFFECTS OF PHYSICAL EXERCISES ON TRIACYLGLYCEROL LEVEL IN SKELETAL MUSCLES IN DIETARY-INDUCED OBESE RATS." Bulletin of Siberian Medicine 13, no. 1 (February 28, 2014): 92–97. http://dx.doi.org/10.20538/1682-0363-2014-1-92-97.
Full textAbstract:
The accumulation of triacylglycerol in peripheral tissues is one of mechanisms of insulin resistance. This paper presents the investigation of the influence of aerobic and anaerobic physical exercises on triacylglycerol level in skeletal muscles and on insulin resistance in dietary-induced obese rats. It is estimated that a high-energy (HE) diet causes the accumulation of triacylglycerols in skeletal muscles that leads to high resistance to insulin. Aerobic and anaerobic physical exercises reduce the level of triacylglycerols in skeletal muscles and raise sensitivity to insulin in obese rats. Physical exercises raise the level of triacylglycerols in skeletal muscles in standard-diet rats that probably is the adaptation to high energy expenditure, but does not lead to high insulin resistance.
5
Isler, Dorothea, Charistine Moeglen, Nigel Gains, and Marcel K. Meier. "Effect of the lipase inhibitor orlistat and of dietary lipid on the absorption of radiolabelled triolein, tri-γ-linolenin and tripalmitin in mice." British Journal of Nutrition 73, no. 6 (June 1995): 851–62. http://dx.doi.org/10.1079/bjn19950090.
Full textAbstract:
Orlistat, a selective inhibitor of gastrointestinal lipases, was used to investigate triacylglycerol absorption. Using mice and a variety of emulsified dietary lipids we found that the absorption of radiolabelled tripalmitin (containing the fatty acid 16:0), but not of triolein (18: 1n−9) or tri-γ-linolenin (18:3n−6), was incomplete from meals rich in esterified palmitate. Further, the absorption of radiolabelled tri-γ-linolenin, from both saturated and unsaturated dietary triacylglycerols, was 1·3- to 2-fold more potently inhibited by orlistat than that of triolein and tripalmitin. These radiolabelled triacylglycerols, which have the same fatty acid in all three positions, may not always be accurate markers of the absorption of dietary triacylglycerols. Orlistat was more effective at inhibiting the absorption of radiolabelled triacylglycerols with which it was codissolved than those added separately, which indicates that equilibration between lipid phases in the stomach may not always be complete. The saturation of the dietary lipid had little or no effect on the potency of orlistat. Orlistat provides a novel approach for studying the role of triacylglycerol hydrolysis in the overall process of triacylglycerol absorption.
6
Zárubová, M., V. Filip, J. Šmidrkal, T. Kůtek, and I. Piska. "The separation of triacylglycerols using unpolar and medium polar capillary columns." Czech Journal of Food Sciences 22, SI - Chem. Reactions in Foods V (January 1, 2004): S123—S126. http://dx.doi.org/10.17221/10633-cjfs.
Full textAbstract:
Commercial by supplied triacylglycerols and synthesized triacylglycerols were used in this project. Analysed triacylglycerols with the range of carbon number (CN) 24–54 consisted of saturated and unsaturated fatty acids. Two capillary columns were used in the analyses of triacylglycerols, namely non-polar (Optima<sup>®</sup>-1-TG) and medium polar (Optima<sup>®</sup>-17-TG) types. In this study the effectiveness of separation (A) of triacylglycerols with different carbon number values, (B) of triacylglycerols with different unsaturation degree, (C) of positional isomers were determined and further possibilities to separate another lipid compounds were analysed. The column Optima<sup>®</sup>-17-TG separates TAG according to the degree of unsaturation while the column Optima<sup>®</sup>-1-TG separates saturated and unsaturated TAG. High temperature capillary gas chromatography was used to determine changes in triacylglycerol composition during the transesterification of structured fats.
7
Christie, W. W., and M. L. Hunter. "Metabolism of the diacetyl derivatives of stereoisomeric monoacyl-sn-glycerols by rat adipocytes in vitro." Biochemical Journal 235, no. 3 (May 1, 1986): 833–38. http://dx.doi.org/10.1042/bj2350833.
Full textAbstract:
Diacetyl long-chain 1(3)- and 2-acyl-sn-glycerols containing either [9,10-3H]oleic acid or [1-14C]palmitic acid were synthesized by partial hydrolysis of the corresponding labelled triacylglycerols and acetylation. They were obtained in a high degree of stereochemical purity by preparative h.p.l.c. on a column containing a diol bonded phase. Each compound was rapidly metabolized by adipocyte preparations in vitro, and a high proportion of the label was recovered in the unesterified fatty acid and triacylglycerol fractions. Negligible amounts of intermediate products of hydrolysis were detected. Triacylglycerols were formed from [9,10-3H]oleic acid and from diacetyl-1(3)-[9,10-3H]oleoyl glycerol precursors at about the same rate, but the 2-isomer was metabolized rather more slowly. The results were consistent with the hypothesis that essentially complete hydrolysis occurred in the medium or at the plasma membrane, through the actions of lipoprotein lipase and monoacylglycerol lipase, and that subsequent esterification took place within the cell. To confirm that no putative intermediate monoacylglycerols were utilized for triacylglycerol biosynthesis via the monacylglycerol pathway, the positional distributions of fatty acids in triacylglycerols from each substrate were determined. No positional selectivity was observed. It was concluded that monoacylglycerols, of an origin exogenous to the tissue, e.g. those derived from plasma triacylglycerols, were not utilized to a significant degree for triacylglycerol biosynthesis in adipose tissue. The diacetyl derivatives of monoacylglycerols may serve as useful stereochemical probes in studies of triacylglycerol biosynthesis via the monoacylglycerol pathway in other tissues.
8
Karpe, F., A. S. Bickerton, L. Hodson, B. A. Fielding, G. D. Tan, and K. N. Frayn. "Removal of triacylglycerols from chylomicrons and VLDL by capillary beds: the basis of lipoprotein remnant formation." Biochemical Society Transactions 35, no. 3 (May 22, 2007): 472–76. http://dx.doi.org/10.1042/bst0350472.
Full textAbstract:
The triacylglycerol content of chylomicrons and VLDL (very-low-density lipoprotein) compete for the same lipolytic pathway in the capillary beds. Although chylomicron triacylglycerols appear to be the favoured substrate for lipoprotein lipase, VLDL particles compete in numbers. Methods to quantify the specific triacylglycerol removal from VLDL and chylomicrons may involve endogenous labelling of the triacylglycerol substrate with stable isotopes in combination with arteriovenous blood sampling in humans. Arteriovenous quantification of remnant lipoproteins suggests that adipose tissue with its high lipoprotein lipase activity is a principal site for generation of remnant lipoproteins. Under circumstances of reduced efficiency in the removal of triacylglycerols from lipoproteins, there is accumulation of remnant lipoproteins, which are potentially atherogenic.
9
Field, F. J., E. Born, H. Chen, S. Murthy, and S. N. Mathur. "Lysophosphatidylcholine increases the secretion of cholesteryl ester-poor triacylglycerol-rich lipoproteins by CaCo-2 cells." Biochemical Journal 304, no. 1 (November 15, 1994): 35–42. http://dx.doi.org/10.1042/bj3040035.
Full textAbstract:
To address the effect of lysophosphatidylcholine on triacylglycerol transport in intestine, CaCo-2 cells, grown on semipermeable supports, were incubated with lysophosphatidylcholine solubilized in 1 mM taurocholate. [14C]Palmitoyllysophosphatidylcholine was readily taken up and incorporated predominantly into cellular phospholipids, particularly phosphatidylcholine. Twenty-five percent of the label was found in triacylglycerols. Compared with labelled cellular phospholipids, labelled triacylglycerols were preferentially secreted. Lysophosphatidylcholine caused a profound decrease in cholesteryl ester synthesis and secretion, whereas cellular triacylglycerol mass and triacylglycerol synthesis and secretion were increased. The effect was more pronounced with oleoyllysophosphatidylcholine than with either palmitoyl- or stearyl-lysophosphatidylcholine. Lysophosphatidylcholine increased the secretion of immunoreactive and newly-synthesized apoprotein B (apoB) without altering the rate of apoB synthesis. Thus, luminal lysophosphatidylcholine and/or its uptake decreases cholesterol esterification and secretion, but increases triacylglycerol synthesis and secretion, triacylglycerol mass accumulation and the secretion of apoB by CaCo-2 cells.
10
Schieferle, Sebastian, Beeke Tappe, Pamela Korte, Martin J. Mueller, and Susanne Berger. "Pathogens and Elicitors Induce Local and Systemic Changes in Triacylglycerol Metabolism in Roots and in Leaves of Arabidopsis thaliana." Biology 10, no. 9 (September 16, 2021): 920. http://dx.doi.org/10.3390/biology10090920.
Full textAbstract:
Interaction of plants with the environment affects lipid metabolism. Changes in the pattern of phospholipids have been reported in response to abiotic stress, particularly accumulation of triacylglycerols, but less is known about the alteration of lipid metabolism in response to biotic stress and leaves have been more intensively studied than roots. This work investigates the levels of lipids in roots as well as leaves of Arabidopsis thaliana in response to pathogens and elicitor molecules by UPLC-TOF-MS. Triacylglycerol levels increased in roots and systemically in leaves upon treatment of roots with the fungus Verticillium longisporum. Upon spray infection of leaves with the bacterial pathogen Pseudomonas syringae, triacylglycerols accumulated locally in leaves but not in roots. Treatment of roots with a bacterial lipopolysaccharide elicitor induced a strong triacylglycerol accumulation in roots and leaves. Induction of the expression of the bacterial effector AVRRPM1 resulted in a dramatic increase of triacylglycerol levels in leaves, indicating that elicitor molecules are sufficient to induce accumulation of triacylglycerols. These results give insight into local and systemic changes to lipid metabolism in roots and leaves in response to biotic stresses.
11
Perez-Martinez, P., J. Lopez-Miranda, JM Ordovas, C. Bellido, C. Marin, P. Gomez, JA Paniagua, JA Moreno, F. Fuentes, and F. Perez-Jimenez. "Postprandial lipemia is modified by the presence of the polymorphism present in the exon 1 variant at the SR-BI gene locus." Journal of Molecular Endocrinology 32, no. 1 (February 1, 2004): 237–45. http://dx.doi.org/10.1677/jme.0.0320237.
Full textAbstract:
It has recently been reported that carriers of the less common allele at the scavenger receptor class B type I (SR-BI) exon 1 polymorphism are more susceptible to the presence of saturated fatty acid in the diet because of a greater increase in LDL cholesterol. Our aim was to determine if this polymorphism could also influence postprandial lipoprotein metabolism, because the SR-BI has been described as a possible mediator in the intestinal absorption of triacylglycerols. Forty-seven normolipidemic volunteers who were homozygous for the E3 allele at the APOE gene were selected [37 homozygous for the common genotype (1/1) at the SR-BI exon 1 polymorphism and 10 heterozygous (1/2)]. They were given a fat-rich meal containing 1 g fat and 7 mg cholesterol per kg body weight and vitamin A 60,000 IU/m2 body surface. Fat accounted for 60% of calories, and protein and carbohydrates accounted for 15% and 25% of energy respectively. Blood samples were taken at time 0, every 1 h until 6 h, and every 2.5 h until 11 h. Total cholesterol and triacylglycerols in plasma, and cholesterol, triacylglycerols and retinyl palmitate in triacylglycerol-rich lipoproteins (large and small triacylglycerol-rich lipoproteins) were determined. Postprandial responses for triacylglycerols and retinyl palmitate in small triacylglycerol-rich lipoproteins were higher in 1/1 individuals than in 1/2 individuals. No other significant differences were noted. Our data show that the presence of the genotype 1/2 is associated with a lower postprandial lipemic response.
12
Kryski Jr., Albert, Terje S. Larsen, Ignasi Ramírez, and David L. Severson. "Methylamine does not inhibit rates of endogenous lipolysis in isolated myocardial cells from rat heart." Canadian Journal of Physiology and Pharmacology 65, no. 2 (February 1, 1987): 226–29. http://dx.doi.org/10.1139/y87-040.
Full textAbstract:
Triacylglycerol lipase activity with a pH optimum of 5 was present in homogenates of myocardial cells from rat heart. Acid lipase activity was inhibited by serum, heparin, and increased ionic strength. Methylamine, a lysosomotropic agent, did not inhibit the basal or isoproterenol-stimulated rate of endogenous lipolysis as measured by glycerol output from control myocytes. Similarly, accelerated rates of glycerol output that are a consequence of an elevation in the intracellular stores of triacylglycerols in myocytes from diabetic rat hearts and from myocytes prepared with free fatty acids in the isolation solutions were not reduced by methylamine. Therefore, the acid lysosomal triacylglycerol lipase must not be involved in the mobilization of endogenous triacylglycerols in myocardial cells from rat heart.
13
Verma, Aparna, Ningombam Sanjib Meitei, Prakash U. Gajbhiye, Mark J. Raftery, and Kiran Ambatipudi. "Comparative Analysis of Milk Triglycerides Profile between Jaffarabadi Buffalo and Holstein Friesian Cow." Metabolites 10, no. 12 (December 11, 2020): 507. http://dx.doi.org/10.3390/metabo10120507.
Full textAbstract:
Milk lipids are known for a variety of biological functions, however; little is known about compositional variation across breeds, especially for Jaffarabadi buffalo, an indigenous Indian breed. Systematic profiling of extracted milk lipids was performed by mass spectrometry across summer and winter in Holstein Friesian cow and Jaffarabadi buffalo. Extensive MS/MS spectral analysis for the identification (ID) of probable lipid species using software followed by manual verification and grading of each assigned lipid species enabled ID based on (a) parent ion, (b) head group, and (c) partial/full acyl characteristic ions for comparative profiling of triacylglycerols between the breeds. Additionally, new triacylglycerol species with short-chain fatty acids were reported by manual interpretation of MS/MS spectra and comparison with curated repositories. Collectively, 1093 triacylglycerol species belonging to 141 unique sum compositions between the replicates of both the animal groups were identified. Relative quantitation at sum composition level followed by statistical analyses revealed changes in relative abundances of triacylglycerol species due to breed, season, and interaction effect of the two. Significant changes in triacylglycerols were observed between breeds (81%) and seasons (59%). When the interaction effect is statistically significant, a higher number of triacylglycerols species in Jaffarabadi has lesser seasonal variation than Holstein Friesian.
14
Kanavouras, A., A. Cert, and R. J. Hernandez. "Oxidation of Olive Oil under Still Air." Food Science and Technology International 11, no. 3 (June 2005): 183–89. http://dx.doi.org/10.1177/1082013205055001.
Full textAbstract:
This work was conducted to analyse the effect of different exposed areas/mass ratios on oil oxidation. Different volumes of the triacylglycerol portion of purified olive oil were placed in glass vials with the same air-exposed area, and stored at 38°C in the dark under still air. The oxidation process was evaluated by determining the peroxide index, K232 and K270 extinction coefficients, fatty acid composition, polar compounds (PCs) and composition of triacylglycerols over time. Substantial differences in the oxidation rate as a function of the air-exposed area to triacylglycerol fraction-mass ratio were observed. The peroxide index exponential increase with time was correlated to the air-exposed area/triacylglycerol fraction mass ratio and the oxidation induction period. Less oxidation derived by-products per gram of triacylglycerols were observed for smaller air-exposed area/triacylglycerol fraction mass ratios. The oxidation process followed an apparent first order chemical reaction. Correlations of the evolution patterns among the various oxidation by-products were also reported.
15
Vlahov, Giovanna. "Determination of the 1,3- and 2-Positional Distribution of Fatty Acids in Olive Oil Triacylglycerols by 13C Nuclear Magnetic Resonance Spectroscopy." Journal of AOAC INTERNATIONAL 89, no. 4 (July 1, 2006): 1071–76. http://dx.doi.org/10.1093/jaoac/89.4.1071.
Full textAbstract:
Abstract Linear models were selected from a large data set acquired for Italian olive oil samples by quantitative 13C nuclear magnetic resonance (NMR) spectroscopy with distortionless enhancement by polarization transfer (DEPT). The models were used to determine the composition of the 2 fatty acid pools esterifying the 1,3- and 2-positions of triacylglycerols. The linear models selected proved that the 1,3- and 2-distribution of saturated, oleate, and linoleate chains in olive oil triacylglycerols deviated from the random distribution pattern to an extent that depended on the concentration of the fatty acid in the whole triacylglycerol. To calculate the fatty acid composition of the 1,3- and 2-positions of olive oil triacylglycerols, the equations of the selected linear models were applied to the fatty acid percentages determined by gas chromatography. These data were compared with the values predicted by the computer method (used to determine the theoretical amounts of triacylglycerols), which is based on the 1,3-random-2-random theory of the fatty acid distribution in triacylglycerols. The biggest differences were found in the linoleate chain, which is the chain that deviated the most from a random distribution pattern. The results confirmed that the 1,3-random-2-random distribution theory provides an approximate method for determining the structure of triacylglycerols; however, the linear models calculated by the direct method that applies 13C NMR spectroscopy represent a more precise measurement of the composition of the 2 fatty acid pools esterifying the 1,3- and 2-positions of triacylglycerols.
16
Kiens, Bente, and Erik A. Richter. "Utilization of skeletal muscle triacylglycerol during postexercise recovery in humans." American Journal of Physiology-Endocrinology and Metabolism 275, no. 2 (August 1, 1998): E332—E337. http://dx.doi.org/10.1152/ajpendo.1998.275.2.e332.
Full textAbstract:
The utilization of muscle triacylglycerols was studied during and after prolonged bicycle ergometer exercise to exhaustion in eight healthy young men. Two days before exercise and in the postexercise recovery period, subjects were fed a carbohydrate-rich diet (65–70% of energy from carbohydrates). Exercise decreased muscle glycogen concentrations from 533 ± 18 to 108 ± 10 mmol/kg dry wt, whereas muscle triacylglycerol concentrations were unaffected (49 ± 5 before vs. 49 ± 8 mmol/kg dry wt after exercise). During the first 18 h after exercise, muscle glycogen concentrations were restored to 409 ± 20 mmol/kg dry wt. In contrast, muscle triacylglycerol concentrations decreased ( P < 0.05) to a nadir of 38 ± 5 mmol/kg dry wt, and muscle lipoprotein lipase activity increased by 72% compared with values before exercise. Pulmonary respiratory exchange ratio values of 0.80–0.82 indicated a relatively high fractional lipid combustion despite the high carbohydrate intake. From 18 to 42 h of recovery, muscle glycogen synthesis was slow and muscle triacylglycerol concentrations and lipoprotein lipase activity were restored to the preexercise values. It is concluded that muscle triacylglycerol concentrations are not diminished during exhaustive glycogen-depleting exercise. However, in the postexercise recovery period, muscle glycogen resynthesis has high metabolic priority, resulting in postexercise lipid combustion despite a high carbohydrate intake. It is suggested that muscle triacylglycerols, and probably very low density lipoprotein triacylglycerols, are important in providing fuel for muscle metabolism in the postexercise recovery period.
17
Brouwers, Martijn C. G. J., Marleen M. J. van Greevenbroek, Vicky M. M. J. Vermeulen, Josephine M. J. P. van Lin, Carla J. H. van der Kallen, and Tjerk W. A. de Bruin. "Five-year follow-up of waist circumference, insulin and ALT levels in familial combined hyperlipidaemia." Clinical Science 113, no. 9 (October 1, 2007): 375–81. http://dx.doi.org/10.1042/cs20070101.
Full textAbstract:
FCHL (familial combined hyperlipidaemia), an entity with many features of the metabolic syndrome, is characterized by changes in cholesterol and triacylglycerol (triglyceride) phenotype over time. The present study was conducted to investigate the relationship of ALT (alanine aminotransferase) levels, used as a surrogate marker for the amount of hepatic fat, with the switch in triacylglycerol phenotype and the increased susceptibility to develop hypertriglyceridaemia in FCHL. BMI (body mass index), waist circumference and plasma triacylglycerols, insulin and ALT levels were measured in 145 FCHL family members and 54 spouses at baseline and after a 5-year follow-up. A switch from normotriglyceridaemia to hypertriglyceridaemia or vice versa, as observed in 22 of 145 FCHL family members, was associated with changes in plasma ALT levels (P=0.001), but not with insulin levels or waist circumference. At 5 years of follow-up, an intra-individual relationship was observed between waist circumference and plasma triacylglycerols, insulin and ALT levels. For each waist circumference, FCHL patients, but not their NL (normolipidaemic) relatives, exhibited higher triacylglycerol and insulin levels than spouses (P<0.001). Remarkably, both FCHL patients and the NL relatives had higher ALT levels for each waist circumference compared with spouses (P<0.001 for FCHL patients, and P=0.035 for NL relatives). In conclusion, the present study shows that the longitudinal relationship of abdominal obesity–ALT is more specific for all FCHL family members, i.e. patients and their NL relatives, than the relationship of abdominal obesity–triacylglycerols. Additionally, the association of ALT with the switch in triacylglycerol phenotype suggests a central role of the liver in the pathogenesis of FCHL.
18
Smaoui, A., and A. Chérif. "Changes in molecular species of triacylglycerols in developing cotton seeds under salt stress." Biochemical Society Transactions 28, no. 6 (December 1, 2000): 902–5. http://dx.doi.org/10.1042/bst0280902.
Full textAbstract:
Cotton plants (Gossypium hirsutum L. cv. S4) were grown and irrigated with increasing salt concentrations: 0, 50, 100 and 150 mM NaCl. Lipids from developing seeds, at stages of 3, 4, 5 and 6 weeks after anthesis, were analysed. High salt dose (150 mM NaCl) affected triacylglycerol levels drastically at the end of ripening. HPLC analysis of triacylglycerols in control seeds showed ten molecular species. Palmitodilinolein (PLL) is the major fraction, representing about 25% of total triacylglycerols. The levels of trilinolein (LLL), palmitolinoleo-olein (PLO) and oleodilinolein (OLL) molecules varied between 13 and 16% of the total. The other molecular species: triolein (OOO), dioleopalmitin (POO) and dipalmitoolein (POP) are minor and do not exceed 5%. Moreover, the composition of triacylglycerol molecular species was almost constant during developing stages of control seeds. However, amounts of triacylglycerol species LLL, OLL and palmitodilinolein (PLL), as expressed on a drymatter basis (mg/g), decreased severely under the highest NaCl concentration, while contents of triacylglycerol species OOO, POO, POP were unchanged. These findings confirm our previous results, which indicated that the amount of linoleic acid in cotton seeds was reduced by salt stress and that the amount of oleic acid remained unchanged.
19
Müllner, Heidemarie, and Günther Daum. "Dynamics of neutral lipid storage in yeast." Acta Biochimica Polonica 51, no. 2 (June 30, 2004): 323–47. http://dx.doi.org/10.18388/abp.2004_3574.
Full textAbstract:
Since energy storage is a basic metabolic process, the synthesis of neutral lipids occurs in all kingdoms of life. The yeast, Saccharomyces cerevisiae, widely accepted as a model eukaryotic cell, contains two classes of neutral lipids, namely steryl esters and triacylglycerols. Triacylglycerols are synthesized through two pathways governed by the acyl-CoA diacylglycerol acyltransferase Dga1p and the phospholipid diacylglycerol acyltransferase Lro1p, respectively. Steryl esters are formed by the two steryl ester synthases Are1p and Are2p, two enzymes with overlapping function which also catalyze triacylglycerol formation, although to a minor extent. Storage of neutral lipids is tightly linked to the biogenesis of so called lipid particles. The role of this compartment in lipid homeostasis and its interplay with other organelles involved in neutral lipid dynamics, especially the endoplasmic reticulum and the plasma membrane, are subject of current investigations. In contrast to neutral lipid formation, mobilization of triacylglycerols and steryl esters in yeast are less characterized at the molecular level. Only recently, the triacylglycerol lipase Tgl3p was identified as the first yeast enzyme of this kind by function. Genes and gene products governing steryl ester mobilization still await identification. Besides biochemical properties of enzymes involved in yeast neutral lipid synthesis and degradation, regulatory aspects of these pathways and cell biological consequences of neutral lipid depletion will be discussed in this minireview.
20
Summers, Lucinda K. M., Barbara A. Fielding, Vera Ilic, Paul T. Quinlan, and Keith N. Frayn. "The effect of triacylglycerol-fatty acid positional distribution on postprandial metabolism in subcutaneous adipose tissue." British Journal of Nutrition 79, no. 2 (February 1998): 141–47. http://dx.doi.org/10.1079/bjn19980025.
Full textAbstract:
We hypothesized that fatty acids at thesn−2 position of chylomicron triacylglycerol are preferentially released into the venous plasma (rather than being taken up and stored in the adipocytes) after hydrolysis by lipoprotein lipase (EC3.1.1.34) in adipose tissue. Arterio–venous differences across adipose tissue were studied in eight healthy subjects on two occasions for 6 h after ingestion of different structured triacylglycerols rich in palmitic acid either at thesn−2 or thesn−1,3 positions. In particular the specific fatty acids making up lipoprotein fractions and plasma non-esterified fatty acids were analysed. After the different meals there were no differences between either postprandial arterialized or venous plasma metabolite concentrations. Chylomicron triacylglycerol extraction in adipose tissue was the same following the two types of fat. There was no difference between the specific fatty acid composition of the postprandial non-esterified fatty acid release from adipose tissue after ingestion of the two triacylglycerols, indicating that there was no preferential release of a saturated fatty acid at thesn−2 position.
21
MATHUR, Satya N., Ella BORN, Shubha MURTHY, and F. Jeffrey FIELD. "Phosphatidylcholine increases the secretion of triacylglycerol-rich lipoproteins by CaCo-2 cells." Biochemical Journal 314, no. 2 (March 1, 1996): 569–75. http://dx.doi.org/10.1042/bj3140569.
Full textAbstract:
The regulation of lipid synthesis and secretion by phosphatidylcholine was investigated in CaCo-2 cells grown on semipermeable filters. In cells incubated with 1 mM taurocholate and 100–500 μM phosphatidylcholine, cholesteryl ester synthesis was decreased, triacylglycerol synthesis was increased modestly, whereas phospholipid synthesis was unaffected. Acyl-CoA–cholesterol acyltransferase activity was decreased secondary to a decrease in the substrate (cholesterol) supply. The basolateral secretion of newly synthesized triacylglycerol and triacylglycerol mass was significantly increased by phosphatidylcholine, whereas cellular triacylglycerol mass decreased. This effect was not specific for phosphatidylcholine as phosphatidylethanolamine and phosphatidylserine also increased the secretion of newly synthesized triacylglycerols. Dioleoylphosphatidylcholine was as effective as egg phosphatidylcholine in increasing triacylglycerol transport. Dipalmitoylphosphatidylcholine, in contrast, was without effect. Phosphatidylcholine also increased the basolateral secretion of apolipoprotein B (apoB) mass without altering apoB mRNA levels. Disruption of the Golgi apparatus by monensin or brefeldin A prevented the increase in apoB secretion by phosphatidylcholine. Compared with microsomes prepared from control cells, those from cells incubated with phosphatidylcholine contained more newly synthesized apoB. The percentage of new synthesized apoB isolated from the lumen of microsomes (as an estimate of apoB destined for secretion), however, was similar in the two preparations. Thus in CaCo-2 cells incubated with phosphatidylcholine, the transport of apoB and triacylglycerols is increased whereas cholesteryl ester synthesis and secretion are decreased. A normally functioning secretory pathway is required for phosphatidylcholine to increase triacylglycerol-rich lipoprotein secretion.
22
Mansbach, C. M., and R. F. Dowell. "Uptake and metabolism of circulating fatty acids by rat intestine." American Journal of Physiology-Gastrointestinal and Liver Physiology 263, no. 6 (December 1, 1992): G927—G933. http://dx.doi.org/10.1152/ajpgi.1992.263.6.g927.
Full textAbstract:
The present study was designed to investigate the uptake and metabolism of circulating fatty acids by the intestinal mucosa in rats actively absorbing glyceryl trioleate given intraduodenally to determine the plasma fatty acid contribution to mucosal triacylglycerol. Rats with duodenal, femoral vein, carotid artery, and mesenteric lymph duct cannulas were used. [3H]oleate was constantly infused into the femoral vein while glyceryl trioleate was infused into the duodenum (135 mumol/h). After 5 h of infusion, a mass and radioactive steady state existed in the plasma and mucosa. At 6 h of infusion, the plasma oleate specific activity was sixfold greater than mucosal oleate and 50 times greater than mucosal triacylglycerol oleate; 86% of the mucosal oleate disintegrations/minute were in triacylglycerol. Chylomicron triacylglycerol oleate specific activity was less than that of the mucosa. Furthermore, the percentage of mucosal triacylglycerol acyl groups composed of oleate was greater than the percentage of oleate in mucosal free fatty acids. The data indicate that fatty acids are taken up by the mucosa during active fat absorption and metabolized primarily to triacylglycerols by the mucosa. The triacylglycerols in the mucosa synthesized from circulating fatty acids are selected against as a precursor of chylomicron triacylglycerol. The results support our previous hypothesis suggesting that the mucosa has at least two pools of neutral lipid (J. Lipid Res. 23: 1009-1019, 1982) and that steady-state conditions as performed here yield different results from previous work using bolus tracer injection techniques.
23
Bauer, Vernon W., Teresa L. Squire, Mark E. Lowe, and Matthew T. Andrews. "Expression of a chimeric retroviral-lipase mRNA confers enhanced lipolysis in a hibernating mammal." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 281, no. 4 (October 1, 2001): R1186—R1192. http://dx.doi.org/10.1152/ajpregu.2001.281.4.r1186.
Full textAbstract:
Hibernating mammals can survive several months without feeding by limiting their carbohydrate catabolism and using triacylglycerols stored in white adipose tissue (WAT) as their primary source of fuel. Here we show that a lipolytic enzyme normally found in the gut, pancreatic triacylglycerol lipase (PTL), is expressed in WAT of hibernating 13-lined ground squirrels ( Spermophilus tridecemlineatus). PTL expressed in WAT is encoded by an unusual chimeric retroviral-PTL mRNA ∼500 bases longer than the predominant PTL message found in other ground squirrel tissues. Seasonal measurements detect the chimeric mRNA and PTL enzymatic activity in WAT before and during hibernation, with both showing their lowest observed levels 1 wk after hibernation concludes in mid-March. PTL is expressed in addition to hormone-sensitive lipase, the enzyme typically responsible for hydrolysis of triacylglycerols in WAT. Because of the distinct catalytic and regulatory properties of both enzymes, this dual-triacylglycerol lipase system provides a means by which the fuel requirements of hibernating 13-lined ground squirrels can be met without interruption.
24
Adán, C., A. Ardévol, X. Remesar, M. Alemany, and J. A. Fernández-López. "Hindleg muscle energy and substrate balances in cold-exposed rats." Journal of Experimental Biology 198, no. 6 (June 1, 1995): 1243–51. http://dx.doi.org/10.1242/jeb.198.6.1243.
Full textAbstract:
Rats chronically cannulated in the carotid artery and the muscular branch of the femoral vein were subjected to a cold (4 degrees C) environment for up to 2 h. The changes in blood flow (measured with 46Sc microspheres) and arterio-venous differences in the concentrations of glucose, lactate, triacylglycerols and amino acids allowed the estimation of substrate (and energy) balances across the hindleg. Mean glucose uptake was 0.28 mumol min-1, mean lactate release was 0.33 mumol min-1 and the free fatty acid basal release of 0.31 mumol min-1 was practically zero upon exposure to the cold; the initial uptake of triacylglycerols gave place to a massive release following exposure. The measurement of PO2, PCO2 and pH also allowed the estimation of oxygen, CO2 and bicarbonate balances and respiratory quotient changes across the hindleg. The contribution of amino acids to the energy balance of the hindleg was assumed to be low. These data were used to determine the sources of energy used to maintain muscle shivering with time. Three distinct phases were observed in hindleg substrate utilization. (1) The onset of shivering, with the use of glucose/glycogen and an increase in lactate efflux. Lipid oxidation was practically zero (respiratory quotient near 1), but the uptake of triacylglycerols from the blood remained unchanged. (2) A substrate-energy shift, with drastically decreased use of glucose/glycogen, and of lactate efflux; utilization of triacylglycerol as practically the sole source of energy (respiratory quotient approximately 0.7); decreasing uptake of triacylglycerol and increased tissue lipid mobilization.(ABSTRACT TRUNCATED AT 250 WORDS)
25
Vistisen, Bodil, Lars Nybo, Xuebing Xu, Carl-Erik Høy, and Bente Kiens. "Minor amounts of plasma medium-chain fatty acids and no improved time trial performance after consuming lipids." Journal of Applied Physiology 95, no. 6 (December 2003): 2434–43. http://dx.doi.org/10.1152/japplphysiol.00118.2003.
Full textAbstract:
Medium-chain triacylglycerols (MCT) have a potential glycogen-saving effect during exercise due to rapid hydrolysis and oxidation. However, studies comparing intake of carbohydrates (CHO) plus 80–90 g MCT with intake of CHO alone have revealed different results. The present study tested performance after consumption of specific structured triacylglycerol, consisting of a mixture of medium-chain fatty acids and long-chain fatty acids, to prevent the adverse effects observed by MCT (pure medium-chain fatty acids) regarding gastrointestinal distress. Seven well-trained subjects cycled 3 h at 55% of maximum O2 uptake during which they ingested CHO or CHO plus specific structured triacylglycerols. Immediately after the constant-load cycling, the subjects performed a time trial of ∼50-min duration. Breath and blood samples were obtained regularly during the experiment. Fatty acid composition of plasma triacylglycerols, fatty acids, and phospholipids was determined. Performance was similar after administration of CHO plus specific structured triacylglycerol [medium-, long-, and medium-chain fatty acid (MLM)] compared with CHO (50.0 ± 1.8 and 50.8 ± 3.6 min, respectively). No plasma 8:0 was detected in the plasma lipid classes, but the amount of phospholipid fatty acids was significantly higher after CHO+MLM compared with CHO intake. The lacking time trial improvement after intake of medium-chain fatty acids might be due to no available 8:0 in the systemic circulation. A higher level of plasma phospholipid fatty acids in the CHO+MLM compared with the CHO group was probably due to endogenous phospholipid release into chylomicrons.
26
Kok, N., M. Roberfroid, A. Robert, and N. Delzenne. "Involvement of lipogenesis in the lower VLDL secretion induced by oligofructose in rats." British Journal of Nutrition 76, no. 6 (December 1996): 881–90. http://dx.doi.org/10.1079/bjn19960094.
Full textAbstract:
Dietary supplementation with oligofructose (OFS; 100 g/kg), a non-digestibleoligomer of β-D-fructose, decreases serum triacylglycerols in serum and VLDL of rats. In order to investigate the role of hepatic metabolism in the hypolipidaemic effect of OFS, male Wistar rats were fed on a standard diet with or without 1OOg Raftilose® P95/kg as OFS source for 30 d. OFS feeding (1) significantly decreased triacylglycerol and phospholipid concentrations in both blood and liver, (2) increased the glycerol-3-phosphate liver content but decreased the hepatic activity of glycerol-3-phosphate acyltransferase (EC 2.3.1.15), suggesting a decrease in acylglycerol synthesis, (3) did not affect the blood non-caterified fatty acid concentrations, but (4) reduced by 54% the capacity of isolated hepatocytesto synthesize and secrete triacylglycerols from labelled acetate; the activity of fatty acid synthase, a key lipogenic enzyme was also significantly decreased. These findings suggest that OFS decreases serum triacylglycerols by reducing de nova fatty acid synthesis in the liver; the lower insulin level in the serum of OFS-fed rats could explain, at least partly, the metabolic effect induced by such nondigestible carbohydrates.
27
Kondo, Mimari, Motohide Aoki, Kazuho Hirai, Ryo Ito, Mikio Tsuzuki, and Norihiro Sato. "Plastoquinone Lipids: Their Synthesis via a Bifunctional Gene and Physiological Function in a Euryhaline Cyanobacterium, Synechococcus sp. PCC 7002." Microorganisms 11, no. 5 (April 30, 2023): 1177. http://dx.doi.org/10.3390/microorganisms11051177.
Full textAbstract:
Eukaryotic photosynthetic organisms synthesize triacylglycerols, which are crucial physiologically as major carbon and energy storage compounds and commercially as food oils and raw materials for carbon-neutral biofuel production. TLC analysis has revealed triacylglycerols are present in several cyanobacteria. However, mass spectrometric analysis has shown that freshwater cyanobacterium, Synechocystis sp. PCC 6803, contains plastoquinone-B and acyl plastoquinol with triacylglycerol-like TLC mobility, concomitantly with the absence of triacylglycerol. Synechocystis contains slr2103, which is responsible for the bifunctional synthesis of plastoquinone-B and acyl plastoquinol and also for NaCl-stress acclimatizing cell growth. However, information is limited on the taxonomical distribution of these plastoquinone lipids, and their synthesis genes and physiological roles in cyanobacteria. In this study, a euryhaline cyanobacterium, Synechococcus sp. PCC 7002, shows the same plastoquinone lipids as those in Synechocystis, although the levels are much lower than in Synechocystis, triacylglycerol being absent. Furthermore, through an analysis of a disruptant to the homolog of slr2103 in Synechococcus, it is found that the slr2103 homolog in Synechococcus, similar to slr2103 in Synechocystis, contributes bifunctionally to the synthesis of plastoquinone-B and acyl plastoquinol; however, the extent of the contribution of the homolog gene to NaCl acclimatization is smaller than that of slr2103 in Synechocystis. These observations suggest strain- or ecoregion-dependent development of the physiological roles of plastoquinone lipids in cyanobacteria and show the necessity to re-evaluate previously identified cyanobacterial triacylglycerol through TLC analysis with mass spectrometric techniques.
28
Schoppen, Stefanie, Ana M. Pérez-Granados, Ángeles Carbajal, Beatriz Sarriá, Francisco J. Sánchez-Muniz, Juan A. Gómez-Gerique, and M. Pilar Vaquero. "Sodium bicarbonated mineral water decreases postprandial lipaemia in postmenopausal women compared to a low mineral water." British Journal of Nutrition 94, no. 4 (October 2005): 582–87. http://dx.doi.org/10.1079/bjn20051515.
Full textAbstract:
The role of bicarbonated mineral waters on lipid metabolism and lipoprotein concentrations in man has scarcely been investigated. The present study aimed to investigate whether drinking sodium bicarbonated mineral water affects postprandial cholesterol and triacylglycerol metabolism in postmenopausal women. In a three-way, randomised, crossover study, eighteen healthy postmenopausal women consumed two sodium bicarbonated mineral waters (bicarbonated mineral water 1 and bicarbonated mineral water 2) and a low mineral water (500 ml of each) with a standard fat-rich meal (4552 kJ; 75·3 g fat). The bicarbonated waters were rich in sodium and bicarbonate and bicarbonated mineral water 1 contained 5·7 times more fluoride than bicarbonated mineral water 2. Fasting blood samples and postprandial blood samples were taken at 30, 60, 120, 240, 360 and 420 min after the end of the meal consumption. Cholesterol and triacylglycerols were determined in serum and chylomicrons. A significant water consumption effect was observed in the total area under the curve (TAUC) of serum and chylomicron triacylglycerols (ANOVA, P=0·008 and P=0·027, respectively). TAUC of serum triacylglycerols for bicarbonated mineral water 2 was significantly lower compared to low mineral water (Bonferroni, P=0·039). Peak concentration of serum triacylglycerols showed a significant water effect (P=0·025). Changes in chylomicron cholesterol were not significantly affected by the type of water. Bicarbonated mineral waters 1 and 2 did not show any significant differences. Drinking sodium bicarbonate-rich mineral waters reduces postprandial lipaemia in healthy postmenopausal women compared to drinking a low mineral water.
29
Kim, Hyun Uk. "Lipid Metabolism in Plants." Plants 9, no. 7 (July 9, 2020): 871. http://dx.doi.org/10.3390/plants9070871.
Full textAbstract:
In plants, lipids function in a variety of ways. Lipids are a major component of biological membranes and are used as a compact energy source for seed germination. Fatty acids, the major lipids in plants, are synthesized in plastid and assembled by glycerolipids or triacylglycerols in endoplasmic reticulum. The metabolism of fatty acids and triacylglycerols is well studied in most Arabidopsis model plants by forward and reverse genetics methods. However, research on the diverse functions of lipids in plants, including various crops, has yet to be completed. The papers of this Special Issue cover the core of the field of plant lipid research on the role of galactolipids in the chloroplast biogenesis from etioplasts and the role of acyltransferases and transcription factors involved in fatty acid and triacylglycerol synthesis. This information will contribute to the expansion of plant lipid research.
30
Górska, Agata, Rita Brzezińska, Klaudia Chojnacka, Joanna Bryś, Ewa Ostrowska-Ligęza, Magdalena Wirkowska-Wojdyła, and Karolina Dolatowska-Żebrowska. "Fat Fraction Qualitative Characteristics for Oat-Based Products." Proceedings 70, no. 1 (November 10, 2020): 93. http://dx.doi.org/10.3390/foods_2020-07707.
Full textAbstract:
Oat-based products are characterized by high fat content with a favorable fatty acid composition. It is of great importance to control the quality of fat fraction as an important indicator of food product safety. The aim of this study was to analyze fat isolated from whole grain oatmeal, mountain oatmeal, and instant oatmeal. We determined the composition of fatty acids and the distribution of fatty acids in triacylglycerol positions using gas chromatography. The oxidative stability of the tested fat was evaluated using pressure differential scanning calorimetry. Melting profiles were determined by differential scanning calorimetry. It was found that fat isolated from oat products is a rich source of unsaturated fatty acids. In the sn-2 position of triacylglycerols, the highest share of oleic acid was found. The fat was characterized by the highest proportion of linoleic acid in the sn-1,3 positions of the triacylglycerols. It was observed that the induction time of oxidation process of fat reached the values of 28.79 min–39.07 min in a test conducted at 120 °C and 5.84 min–7.37 min at 140 °C. The analyzed melting profiles showed the presence of peaks indicating the presence of low-melting triacylglycerols containing mainly unsaturated fatty acids.
31
Górecka, M., M. Synak, L. Budohoski, J. Langfort, S. Moskalewski, and E. Żernicka. "Palmitic acid uptake by the rat soleus muscle in vitro." Biochemistry and Cell Biology 79, no. 4 (August 1, 2001): 419–24. http://dx.doi.org/10.1139/o01-028.
Full textAbstract:
The rate of fatty acid uptake, oxidation, and deposition in skeletal muscles in relation to total and unbound to albumin fatty acids concentration in the medium were investigated in the incubated rat soleus muscle. An immunohistochemical technique was applied to demonstrate whether the albumin-bound fatty acid complex from the medium penetrates well within all areas of the muscle strips. It was found that the percentage of incorporation of palmitic acid into intramuscular lipids was fairly constant, independently of the fatty acid concentration in the medium, and amounted to 6372% for triacylglycerols, 712% for diacylglycerols-monoacylglycerols, and 1926% for phospholipids. Both palmitic acid incorporation into the muscle triacylglycerol stores and its oxidation to CO2closely correlated with an increase in both total and unbound to albumin fatty acid concentrations in the incubation medium. Under conditions of increased total but constant unbound to albumin palmitic acid concentrations, the incorporation of palmitic acid into triacylglycerols and its oxidation to CO2were also increased, but to a lower extent. This supports the hypothesis that the cellular fatty acid metabolism depends not only on the availability of fatty acids unbound to albumin, but also on the availability of fatty acids complexed to albumin.Key words: skeletal muscle, fatty acids, triacylglycerols, phospholipids.
32
Palazzo, A. J., K. U. Malik, and M. T. Weis. "Vasopressin stimulates the mobilization and metabolism of triacylglycerol in perfused rabbit hearts." American Journal of Physiology-Heart and Circulatory Physiology 260, no. 2 (February 1, 1991): H604—H612. http://dx.doi.org/10.1152/ajpheart.1991.260.2.h604.
Full textAbstract:
Vasopressin stimulates several metabolic processes, including glycogenolysis, gluconeogenesis, and fatty acid oxidation, and promotes lipolysis in rabbit and hamster suprarenal adipose tissue. This study was conducted to determine whether arginine vasopressin (AVP) stimulates the metabolism of triacylglycerols in the isolated perfused rabbit heart. Since the basal output of glycerol in the rabbit heart is very low, the triacylglycerol pool was labeled with [3H]triolein, and triacylglycerol metabolism was followed by analysis of the radioactive products in the perfusate. Administration of AVP (100 ng, 92 pmol) produced a 10-fold increase in the perfusate radioactivity associated with free fatty acids and mono- and diglycerides, as well as an 8-fold increase in the effluent radioactivity associated with triacylglycerol. The V1-receptor antagonist d[(CH2)5Tyr(Me)]AVP blocked the AVP-induced increase in the output of radioactivity in a dose-related manner. The V2-receptor agonist desmopressin (DDAVP) did not increase the outflow of radioactivity. Likewise, AVP-induced release of radioactivity was inhibited when Ca2+ was omitted from the perfusion buffer. Analysis of total lipid extracts of hearts labeled with [3H]triolein showed that the residual radioactivity was associated almost exclusively with authentic triolein both before and after AVP treatment. These data suggest that AVP promotes triacylglycerol mobilization and utilization and that these processes are Ca2+ dependent and mediated by the V1-receptor. Since free fatty acids derived from triacylglycerols are the preferred metabolic substrate for the heart and since plasma AVP levels increase in cardiac stress states such as shock, these findings suggest a metabolic function of AVP in cardiovascular stress states.
33
Khor, Yih Phing, Khai Shin Hew, Faridah Abas, Oi Ming Lai, Ling Zhi Cheong, Imededdine Arbi Nehdi, Hassen Mohamed Sbihi, Mohamed Mossad Gewik, and Chin Ping Tan. "Oxidation and Polymerization of Triacylglycerols: In-Depth Investigations towards the Impact of Heating Profiles." Foods 8, no. 10 (October 11, 2019): 475. http://dx.doi.org/10.3390/foods8100475.
Full textAbstract:
The stability of refined, bleached, and deodorized palm olein (RBDPO) was studied under controlled heating conditions. RBDPO was heated continuously for 24 h at 160, 170, and 180 °C, with oil sampled at four hour intervals. Thermo-oxidative alterations were measured through various parameters, such as monomeric oxidized triacylglycerols (oxTAG), total polar compounds (TPC), polymerized triacylglycerols (PTG), oxidative stability, and fatty acid composition. After 24 h of heating, the TPC and triacylglycerol oligomers showed a linear increase with heating time at all heating temperatures. At the end of the heating study, more epoxy acids were formed than keto and hydroxy acids. Moreover, caprylic acid, which was not present in fresh oil, was formed in significant amounts. The increase in oxTAG was strongly correlated with the increase in the p-anisidine value and total oxidation value. The decreases in diacylglycerol and free fatty acids were strongly correlated with an increase in PTG.
34
Herzberg, Gene R. "The 1990 Borden Award Lecture Dietary regulation of fatty acid and triglyceride metabolism." Canadian Journal of Physiology and Pharmacology 69, no. 11 (November 1, 1991): 1637–47. http://dx.doi.org/10.1139/y91-242.
Full textAbstract:
The level of circulating triacylglycerols is determined by the balance between their delivery into the plasma and their removal from it. Plasma triacylglycerols are derived either from dietary fat as chylomicrons or from endogenous hepatic synthesis as very low density lipoproteins. Their removal occurs through the action of lipoprotein lipase after which the fatty acids are either stored in adipose tissue or oxidized, primarily in skeletal muscle and heart. The composition of the diet has been shown to influence many of these processes. Hepatic fatty acid synthesis and triacylglycerol secretion are affected by the quantity and composition of dietary fat, carbohydrate, and protein. Polyunsaturated but not saturated fats reduce hepatic fatty acid synthesis by decreasing the amount of the lipogenic enzymes needed for de novo fatty acid synthesis. Dietary fish oils are particularly effective at reducing both fatty acid synthesis and triacylglycerol secretion and as a result are hypotriacylglycerolemic, particularly in hypertriacylglycerolemic individuals. In addition, dietary fish oils can increase the oxidation of fatty acids and lead to increased activity of lipoprotein lipase in skeletal muscle and heart. It appears that the hypotriacylglycerolemic effect of dietary fish oils is mediated by effects on both synthesis and removal of circulating triacylglycerols.Key words: lipid, fish oil, fructose, liver, adipose tissue, oxidation.
35
Hexeberg, Sofie, Erik Hexeberg, Nina Willumsen, and Rolf K. Berge. "A study on lipid metabolism in heart and liver of cholesterol-and pectin-fed rats." British Journal of Nutrition 71, no. 2 (February 1994): 181–92. http://dx.doi.org/10.1079/bjn19940125.
Full textAbstract:
Pectin is known as a cholesterol-reducing dietary fibre, and in the present study we addressed the question whether pectin affected the quantity of lipid in droplets in the myocardial cells and of lipid in the liver cells. Male Wistar rats received either a diet containing cholesterol or a standard diet without cholesterol with 0, 50 or 100 g pectin/kg incorporated for 10 d. The fractional volume of lipid droplets in the myocardial cells decreased as a function of pectin dose in both the standard-fed and the cholesterol-fed rats. Serum cholesterol was significantly reduced in both groups after addition of 100 g pectin/kg diet. The cholesterol diet increased the liver cholesterol level, and 100 g pectin/kg diet resulted in a lower concentration of liver cholesterol in the cholesterol-fed animals, but the influence on standard-fed rats was modest. Hydroxymethylglutaryl-CoA reductase (EC 1.1.1.88; HMG-CoA reductase) activity-increased when pectin was given in the standard diet. Liver triacylglycerol level increased after cholesterol and pectin feeding. Mitochondrial fatty acid oxidation and phosphatidate phosphohydrolase (EC 3.1.3.4) activity tended to decrease, whereas the peroxisomal fatty acid oxidation and acyl-CoA oxidase activity were unchanged. Increased hepatic triacylglycerol content by cholesterol and pectin treatment may be due to inhibited mitochondrial fatty acid oxidation along with increased availability of fatty acid for esterification and triacylglycerol synthesis. The presence of pectin in the diets of cholesterol-fed rats resulted in increased hepatic concentration of triacylglycerols and increased mitochondrial fatty acid oxidation. In this case the hepatic accumulation of triacylglycerol may be mediated by a reduced efflux of triacylglycerols from the liver.
36
Cunnane, S. C., and Z. Y. Chen. "Quantitative changes in long-chain fatty acids during fetal and early postnatal development in rats." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 262, no. 1 (January 1, 1992): R14—R19. http://dx.doi.org/10.1152/ajpregu.1992.262.1.r14.
Full textAbstract:
The quantitative importance of triacylglycerol as a source of total essential fatty acids during early postnatal development is reported in the accompanying article. Our objective here was to measure the quantitative changes in individual long-chain fatty acids in specific lipid classes of the carcass, liver, and brain of the developing rat mainly to describe the relative accumulation of long-chain vs. precursor fatty acids. Fatty acids in carcass phosphatidylcholine (micrograms/g) were lower at fetal days 18-21 than at either fetal day 15 or postnatal days +3 to +9. Individual long-chain fatty acids in liver phosphatidylcholine and phosphatidylethanolamine increased markedly by day +3 postnatally, whereas in brain phosphatidylethanolamine, the postnatal increase was delayed to between days +6 and +9. Fatty acids in carcass and liver triacylglycerols increased quantitatively by 10- to 300-fold from fetal day 21 to postnatal day +3 with amounts of both arachidonic and docosahexaenoic acid equaling linoleic acid. The ratios of linoleic and alpha-linolenic acids to respective long-chain products were significantly higher in triacylglycerols, whereas that of stearic to oleic acid was higher in phospholipids. We conclude that, during early postnatal life, oleic, linoleic, and alpha-linolenic acids are required in quantitatively greater amounts in triacylglycerols, whereas stearic acid and long-chain essential fatty acids are required in phospholipids.
37
Kmiecik, Dominik, Monika Fedko, Aleksander Siger, and Bartosz Kulczyński. "Degradation of Tocopherol Molecules and Its Impact on the Polymerization of Triacylglycerols during Heat Treatment of Oil." Molecules 24, no. 24 (December 12, 2019): 4555. http://dx.doi.org/10.3390/molecules24244555.
Full textAbstract:
The aim of the study was to analyze the influence of the surface area to volume ratio of pressed and refined rapeseed oils on the changes in tocopherol content and polymerization of triacylglycerols during heating. In the study the pressed and refined rapeseed oil was heated at 170 °C, during 6, 12, and 18 h with three different surface area to volume (s/v) ratios (0.378, 0.189, and 0.126 cm−1). During heating, a decrease in tocopherols and increases in dimers, trimers, and oligomers of triacylglycerols were observed. However, the changes were dependent on the surface area to volume ratio used, type of oil and time of heating. The biggest changes were observed in oil with the biggest s/v ratio (0.378 cm−1), and the lowest when the s/v ratio was 0.126 cm−1. The pressed oil was characterized by faster degradation of tocopherols and slower increase of triacylglycerol polymer levels compared to refined oil.
38
He, Yue, Candice Yam, Kyle Pomraning, Jacqueline S. R. Chin, Joanne Y. Yew, Michael Freitag, and Snezhana Oliferenko. "Increase in cellular triacylglycerol content and emergence of large ER-associated lipid droplets in the absence of CDP-DG synthase function." Molecular Biology of the Cell 25, no. 25 (December 15, 2014): 4083–95. http://dx.doi.org/10.1091/mbc.e14-03-0832.
Full textAbstract:
Excess fatty acids and sterols are stored as triacylglycerols and sterol esters in specialized cellular organelles, called lipid droplets. Understanding what determines the cellular amount of neutral lipids and their packaging into lipid droplets is of fundamental and applied interest. Using two species of fission yeast, we show that cycling cells deficient in the function of the ER-resident CDP-DG synthase Cds1 exhibit markedly increased triacylglycerol content and assemble large lipid droplets closely associated with the ER membranes. We demonstrate that these unusual structures recruit the triacylglycerol synthesis machinery and grow by expansion rather than by fusion. Our results suggest that interfering with the CDP-DG route of phosphatidic acid utilization rewires cellular metabolism to adopt a triacylglycerol-rich lifestyle reliant on the Kennedy pathway.
39
Graulet, Benoît, Dominique Gruffat-Mouty, Denys Durand, and Dominique Bauchart. "Effects of milk diets containing beef tallow or coconut oil on the fatty acid metabolism of liver slices from preruminant calves." British Journal of Nutrition 84, no. 3 (September 2000): 309–18. http://dx.doi.org/10.1017/s0007114500001586.
Full textAbstract:
Coconut oil (CO) induces a triacylglycerol infiltration in the hepatocytes of preruminant calves when given as the sole source of fat in the milk diet over a long-term period. Metabolic pathways potentially involved in this hepatic triacylglycerol accumulation were studied by in vitro methods on liver slices from preruminant Holstein × Friesian male calves fed a conventional milk diet containing CO (n 5) or beef tallow (BT, n 5) for 19 d. Liver slices were incubated for 12 h in the presence of 0·8 mM-[14C] oleate or -[14C] laurate added to the medium. Fatty acid oxidation was determined by measuring the production of CO2 (total oxidation) and acid-soluble products (partial oxidation). Production of CO2 was 1·7–3·6-fold lower (P 0·0490) and production of acid-soluble products tended to be lower (P = 0·0625) in liver slices of CO- than BT-fed calves. Fatty acid esterification as neutral lipids was 2·6– to 3·1–fold higher (P = 0·0088) in liver slices prepared from calves fed the CO diet compared with calves fed the BT diet. By contrast with what occurs in the liver of rats fed CO, the increase in neutral lipid production did not stimulate VLDL secretion by the hepatocytes of calves fed with CO, leading to a triacylglycerol accumulation in the cytosol. It could be explained by the reduction of fatty acid oxidation favouring esterification in the form of triacylglycerols, in association with a limited availability of triacylglycerols and/or apolipoprotein B for VLDL packaging and subsequent secretion.
40
Hayes, Johnnie R., Deborah H. Pence, Saul Scheinbach, Ronald P. D'Amelia, Lawrence P. Klemann, Nelson H. Wilson, and John W. Finley. "Review of triacylglycerol digestion, absorption, and metabolism with respect to Salatrim triacylglycerols." Journal of Agricultural and Food Chemistry 42, no. 2 (February 1994): 474–83. http://dx.doi.org/10.1021/jf00038a043.
Full text
41
Hallebeek, J. M., and A. C. Beynen. "Effect of dietary medium chain triacylglycerols on plasma triacylglycerol levels in horses." Archiv für Tierernaehrung 54, no. 2 (May 2001): 159–71. http://dx.doi.org/10.1080/17450390109381974.
Full text
42
Beer-Ljubić, B., J. Aladrović, S. Milinković-Tur, M. Lazarus, and I. Pušić. "Effect of fasting on lipid metabolism and oxidative stability in fattening chicken fed a diet supplemented with organic selenium." Archives Animal Breeding 55, no. 5 (October 10, 2012): 485–95. http://dx.doi.org/10.5194/aab-55-485-2012.
Full textAbstract:
Abstract. The aim of the study was to assess the effect of organic selenium dietary supplementation on serum and tissue lipid composition after fattening period and after 48 h fasting in fattening chicken. The study was performed in the Ross hybrid line chicken divided into two groups: control group fed standard diet and Sel Plex group fed standard diet supplemented with 0.3 ppm organic selenium. Blood, liver, intestine and adipose tissue samples were taken upon fattening completion and after 48 h fasting. Total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triacylglycerol and lipoprotein concentrations were determined in serum, whereas total and free cholesterol, triacylglycerol, lipid peroxide and selenium concentrations and glutathione peroxidase activity (GSH-Px) were determined in tissue samples. During fattening period, the correlation of organic selenium with lipid metabolism manifested as decreased concentrations of serum triacylglycerols and very-low-density lipoprotein (VLDL) (P<0.05), liver triacylglycerols (P<0.05), adipose tissue cholesterol (P<0.05) and small intestine cholesterol (P<0.05), and reduced lipid peroxidation (P<0.05). Upon chicken exposure to 48 h fasting, organic selenium supplementation resulted in increased free cholesterol concentration in adipose tissue (P<0.05), GSH-Px activity in the liver (P<0.05), and selenium (P<0.05) accumulation in the liver.
43
HEYDINGER, JENIFER A., and DILIP K. NAKHASI. "MEDIUM CHAIN TRIACYLGLYCEROLS." Journal of Food Lipids 3, no. 4 (December 1996): 251–57. http://dx.doi.org/10.1111/j.1745-4522.1996.tb00072.x.
Full text
44
Lehner, Richard, and A. Kuksis. "Biosynthesis of triacylglycerols." Progress in Lipid Research 35, no. 2 (June 1996): 169–201. http://dx.doi.org/10.1016/0163-7827(96)00005-7.
Full text
45
Fruehwirth, Sarah, Sofie Zehentner, Mohammed Salim, Sonja Sterneder, Johanna Tiroch, Barbara Lieder, Martin Zehl, Veronika Somoza, and Marc Pignitter. "In Vitro Digestion of Grape Seed Oil Inhibits Phospholipid-Regulating Effects of Oxidized Lipids." Biomolecules 10, no. 5 (May 2, 2020): 708. http://dx.doi.org/10.3390/biom10050708.
Full textAbstract:
The intake of dietary lipids is known to affect the composition of phospholipids in gastrointestinal cells, thereby influencing passive lipid absorption. However, dietary lipids rich in polyunsaturated fatty acids, such as vegetable oils, are prone to oxidation. Studies investigating the phospholipid-regulating effect of oxidized lipids are lacking. We aimed at identifying the effects of oxidized lipids from moderately (18.8 ± 0.39 meq O2/kg oil) and highly (28.2 ± 0.39 meq O2/kg oil) oxidized and in vitro digested cold-pressed grape seed oils on phospholipids in human gastric tumor cells (HGT-1). The oils were analyzed for their antioxidant constituents as well as their oxidized triacylglycerol profile by LC-MS/MS before and after a simulated digestion. The HGT-1 cells were treated with polar oil fractions containing epoxidized and hydroperoxidized triacylglycerols for up to six hours. Oxidized triacylglycerols from grape seed oil were shown to decrease during the in vitro digestion up to 40% in moderately and highly oxidized oil. The incubation of HGT-1 cells with oxidized lipids from non-digested oils induced the formation of cellular phospholipids consisting of unsaturated fatty acids, such as phosphocholines PC (18:1/22:6), PC (18:2/0:0), phosphoserine PS (42:8) and phosphoinositol PI (20:4/0:0), by about 40%–60%, whereas the incubation with the in vitro digested oils did not affect the phospholipid metabolism. Hence, the gastric conditions inhibited the phospholipid-regulating effect of oxidized triacylglycerols (oxTAGs), with potential implications in lipid absorption.
46
Radom, J., R. Salvayre, T. Levade, and L. Douste-Blazy. "Influence of chain length of pyrene fatty acids on their uptake and metabolism by Epstein–Barr-virus-transformed lymphoid cell lines from a patient with multisystemic lipid storage myopathy and from control subjects." Biochemical Journal 269, no. 1 (July 1, 1990): 107–13. http://dx.doi.org/10.1042/bj2690107.
Full textAbstract:
The uptake and intracellular metabolism of 4-(1-pyrene)butanoic acid (P4), 10-(1-pyrene)decanoic acid (P10) and 12-(1-pyrene)dodecanoic acid (P12) were investigated in cultured lymphoid cell lines from normal individuals and from a patient with multisystemic lipid storage myopathy (MLSM). The cellular uptake was shown to be dependent on the fatty-acid chain length, but no significant difference in the uptake of pyrene fatty acids was observed between MLSM and control lymphoid cells. After incubation for 1 h the distribution of fluorescent fatty acids taken up by the lymphoid cell lines also differed with the chain length, most of the fluorescence being associated with phospholipid and triacylglycerols. In contrast with P10 and P12, P4 was not incorporated into neutral lipids. When the cells were incubated for 24 h with the pyrene fatty acids, the amount of fluorescent lipids synthesized by the cells was proportional to the fatty acid concentration in the culture medium. After a 24 h incubation in the presence of P10 or P12, at any concentration, the fluorescent triacylglycerol content of MLSM cells was 2-5-fold higher than that of control cells. Concentrations of pyrene fatty acids higher than 40 microM seemed to be more toxic for mutant cells than for control cells. This cytotoxicity was dependent on the fluorescent-fatty-acid chain length (P12 greater than P10 greater than P4). Pulse-chase experiments permitted one to demonstrate the defect in the degradation of endogenously biosynthesized triacylglycerols in MLSM cells (residual activity was around 10-25% of controls on the basis of half-lives and initial rates of P10- or P12-labelled-triacylglycerol catabolism); MLSM lymphoid cells exhibited a mild phenotypic expression of the lipid storage (less severe than that observed in fibroblasts). P4 was not utilized in the synthesis of triacylglycerols, and thus did not accumulate in MLSM cells: this suggests that natural short-chain fatty acids might induce a lesser lipid storage in this disease.
47
Schmidt, Š., M. Vajdák, S. Sekretár, and V. Koman. "Effect of some refining steps on rapeseed oil triacylglycerol structures." Czech Journal of Food Sciences 22, SI - Chem. Reactions in Foods V (January 1, 2004): S346—S348. http://dx.doi.org/10.17221/10698-cjfs.
Full textAbstract:
Determination of fatty acids at sn-2 position in rapeeed oil triacylglycerols with low content of erucic acid is desribed. Oleic acid constitues of 48% of the fatty acids, linoleic acid 37.8%, linolenic acid 13.5%, and small amounts of the usual saturated acids make up the remainder. The effect of industrial alkali refining (degumming and neutralization), bleaching, deodorization and interesterification was studied. The use of different refining steps did not cause any or only mild triacylglycerol structure modification, other than interesterification, obviously.
48
Gylling, Helena, and Tatu A. Miettinen. "Absorption and metabolism of cholesterol in familial hypercholesterolemia." Clinical Science 76, no. 3 (March 1, 1989): 297–301. http://dx.doi.org/10.1042/cs0760297.
Full textAbstract:
1. The present study investigated the role of intestinal cholesterol absorption in the regulation of cholesterol metabolism and serum lipoprotein levels in 22 patients with heterozygous familial hypercholesterolaemia on low to normal cholesterol intake. 2. The results showed that the higher the dietary cholesterol absorption, the lower was the overall synthesis of cholesterol. Efficient cholesterol absorption actually reduced the elimination of cholesterol as faecal neutral sterols but not consistently as bile acids. 3. In multifactorial analysis, body mass index and dietary plant sterols were negatively associated with cholesterol absorption, but were unrelated to cholesterol synthesis. 4. Fractional cholesterol absorption was related only to the serum very-low-density triacylglycerol level. It was not associated with the total or low-density lipoprotein cholesterol levels. On the other hand, cholesterol synthesis was significantly associated with the serum concentrations of very-low-density lipoprotein and intermediate-density lipoprotein cholesterol and triacylglycerols, and with those of low-density lipoprotein triacylglycerols. 5. In conclusion, dietary cholesterol absorption is an essential regulator of cholesterol homoeostasis in familial hypercholesterolaemia, even in patients on low cholesterol intake.
49
Dimand, R. J., E. M. Bradbury, and K. L. Cox. "Determination of triacylglycerol lipase activity using carbon-13-labeled triacylglycerols and nuclear magnetic resonance spectroscopy: Evidence that hepatic lipase hydrolyzes medium-chain triacylglycerols." Magnetic Resonance in Medicine 9, no. 2 (February 1989): 273–77. http://dx.doi.org/10.1002/mrm.1910090212.
Full text
50
MASANA, Ll, G. FEBRER, J. CAVANNA, M. G. BARONI, W. MARZ, M. M. HOFFMANN, B. SHINE, and D. J. GALTON. "Common genetic variants that relate to disorders of lipid transport in Spanish subjects with premature coronary artery disease." Clinical Science 100, no. 2 (January 2, 2001): 183–90. http://dx.doi.org/10.1042/cs1000183.
Full textAbstract:
Fifteen common polymorphic variants at six loci (apolipoproteins AI, B, CIII and E, hepatic lipase and lipoprotein lipase) involved in plasma lipid transport have been studied in 210 northern Spanish men, of whom 98 had proven coronary artery disease. The other 112 men were clinically free from coronary artery disease and acted as controls. The genotypes were investigated for relationships with plasma lipid and lipoprotein levels, as well as for the presence of coronary artery disease. As expected, the mean levels of plasma triacylglycerols (triglycerides) and lipoprotein (a) and the number of smokers were significantly higher in the disease group, and high-density lipoprotein (HDL)-cholesterol was significantly lower. Surprisingly, plasma cholesterol and low-density lipoprotein cholesterol were not different between the two groups. With regard to the common mutations, plasma triacylglycerol levels were related to the HindIII variants of lipoprotein lipase (P < 0.05), to the apolipoprotein CIII variant (C3175G in exon 4) and to the apolipoprotein AI XmnI polymorphisms (P < 0.05 and P < 0.02 respectively). The apolipoprotein E variants were related to plasma cholesterol (P < 0.05), HDL-cholesterol (P < 0.02), plasma triacylglycerols (P < 0.05) and the triacylglycerol/HDL ratio (P < 0.01). Only the three-codon insertion/deletion variants of the apolipoprotein B signal peptide region discriminated between the two groups with or without arterial disease (P = 0.02). The possible functional effects of these common mutations are discussed.