Search results for "Lipids"
showing 10 items of 2228 documents
Phospholipid-based reverse micelles.
1990
Physicochemical investigations on the aggregation of phospholipids (mainly phosphatidylcholines) in organic solvents are reviewed and compared with the aggregation behaviour of phospholipids in aqueous medium. In particular we review the data showing that phosphatidylcholines (lecithins) form reverse micellar structures in certain apolar solvents. In these systems not only low molecular weight compounds but also catalytically active enzymes and entire cells can be solubilized. In addition, highly viscous phosphatidylcholine gels can be obtained in organic solvents upon solubilizing a critical amount of water. Generally, phospholipid-based reverse micelles can be regarded as thermodynamicall…
Utilization of different dietary lipid sources at high level in herbivorous grass carp (Ctenopharyngodon idella): mechanism related to hepatic fatty …
2008
Herbivorous grass carp (Ctenopharyngodon idella) has been reported to exhibit low capacity to utilize high dietary lipid, but different lipid sources might affect this limited capacity. In order to compare the effects of different lipid sources with different lipid levels, juvenile grass carp were fed one of nine diets containing three oils [lard, plant oil mixed by maize and linseed oil, and n-3 high unsaturated fatty acid-enriched (HUFA-enriched) fish oil] at three lipid levels (20, 60 and 100 g kg(-1) dry diet) for 8 weeks. Decreased feed intake, poor growth performance, hepatic pathology and higher blood lipid peroxidation were found in 60 and 100 g kg(-1) fish oil groups. Conversely, i…
Polyunsaturated fatty acids and Plasmalogens in diabetics
2012
Purpose Plasmalogens (PLS) are phospholipids characterized by a vinyl ether bond and a preferential esterification of polyunsaturated fatty acids (PUFA). We have previously shown that the lack of PLS leads to retinal hyper-capillarization. We hypothesize that PLS are negative regulators of vascular development, and aimed to check their circulating levels in diabetic patients. Methods Blood samples were collected from 88 patients and 14 control subjects. Among diabetics we had 14 patients without diabetic retinopathy (DR), 12 with a mild non proliferative DR, 12 with a moderate non proliferative DR, 22 with a severe non proliferative DR and 24 with a proliferative DR (PDR). Erythrocytes were…
Acides gras des phospholipides plaquettaires et des lipides plasmatiques chez le rat obése Zucker
1988
AbstractThe purpose of this work was to see whether hyperlipaemia observed in genetically obese Zucker rats (fa/fa) was associated with differences in fatty-acid composition of plasma triacylglycerols, plasma phospholipids and of platelet phospholipids, in comparison with the control lean rats (Fa/-).Results showed that plasma triacylglycerols and phospholipids were increased in obese rats. In triacylglycerols, the amount of saturated and monounsaturated fatty acids was highly increased whereas the amount of the n-6 and n-3 polyunsaturated fatty acids was little modified. In plasma phospholipids, saturated and monounsaturated fatty acids were also increased, as were the n-3 fatty acids (exc…
Lipid and fatty acid profile of the retina, RPE/choroid and lacrimal gland, and associations with dietary fatty acids in human subjects
2008
Purpose The contribution of dietary lipids to the accumulation of lipids in the retina during ageing and in the course of age related maculopathies remains under debate. Our objective was to establish associations between fatty acid profiles of ocular structures, and adipose tissue as a surrogate for the past dietary intake of the subjects. Methods Lipids and fatty acids were analyzed by tandem thin-layer chromatography-flame ionization detection and gas chromatography-flame ionization detection from the neural retina, RPE/choroid, lacrimal gland and adipose tissue, collected from 19 women and 8 men, aged 59–95 years. Results DHA concentrations in the neural retina were positively associate…
Depressed Prostaglandin Release from Peritoneal Cells Induced by a T Cell Adjuvant, Lentinan
1979
Abstract PGE and PGF release from peritoneal exudate cells was studied in mice after injection with two s (1–3) glucans, the antitumor active lentinan and the inactive pachyman. 4 days after injection of both polysaccharides, the spontaneous and phagocytosis-induced PGE and PGF release was markedly suppressed. However, only the immunopotentiator lentinan induced peritoneal exudate cells which exhibited a longer lasting diminished PG release. The data suggest that the T cell adjuvant lentinan may potentiate cellular immune responses by reducing synthesis of immune suppressive prostaglandins from peritoneal exudate cells.
Time-dependent monomerization of gramicidin A, enhanced by phosphatidylcholine in non-polar solvents
1986
Abstract The usefulness of size-exclusion high-performance liquid chromatography for the study of gramicidin A dimer—monomer conformational equilibrium in non
Membrane Lipid-Polypeptide Molecular Associations in Non Aqueous Solvent. Effect of Phosphatidylcholine Concentration and Temperature and their Influ…
1986
Abstract The use of an Ultrastyragel 500 A column for the study of interactions between phosphatidylcholine and gramicidin A in tetra-hydrofuran is described. Analysis of vacant peak has allowed to establish the influence that eluent lipid composition, concentration of injected gramicidin and temperature have on the interaction. At 20[ddot] C, for the assayed phospholipid concentration range (0.04 to 0.14 %, w/v), the lipid/polypeptide molar binding ratio, BR, varies from 1.3 to 6.9. An increase in temperature from 20 to 40[ddot] C causes a decrease in BR of about 20 %. On the other hand, the interaction releases some of the water bound to the lipid polar head, suggesting that the binding i…
Tricks and Tracks in the Identification and Quantification of Endocannabinoids
2013
Abstract The endocannabinoid system serves pivotal roles in a diverse range of physiological and pathophysiological states, including behavior, pain, schizophrenia, obesity, Alzheimer disease, multiple sclerosis and cardiovascular disease. A number of endocannabinoids (eCBs) and their receptors have been characterised and identified in a plethora of biological matrices. The eCBs include N-arachidonoyl ethanolamine (anandamide), 2-arachidonoyl glycerol, 2-arachidonoyl glyceryl ether (noladin ether), O-arachidonoyl ethanolamine (virodhamine) and N-arachidonoyl dopamine. Advanced targeted mass spectrometry methods, particularly the selected reaction monitoring, has facilitated sensitive quanti…
Phorbol Esters and Muscarinic Receptor Agonists Activate Phospholipase D in Heart and Brain
1991
Phospholipase D (PLD) hydrolyzes phosphatidylcholine and thereby seems to play a key role in a novel pathway of signal transduction. PLD activity in rat hippocampal slices and atria of rat, guinea pig and chicken hearts was determined by measuring the catalytic products choline (Ch), phosphatidic acid (PA) and, in the presence of a primary alcohol, phosphatidylpropanol or phosphatidylethanol. It was found that the PLD activity was high, even under resting conditions, in both tissues, especially in the hippocampus, and that the enzyme activity could be enhanced by activation of protein kinase C and by muscarinic receptor stimulation.