Search results for "acide"
showing 10 items of 100 documents
Alpha-lipoic acid: molecular mechanisms and therapeutic potential in diabetes.
2015
International audience; Diabetes is a chronic metabolic disease with a high prevalence worldwide. Diabetes and insulin resistance are associated with the development of cardiovascular and nervous diseases. The development of these disorders reflects complex pathological processes in which the oxidative stress caused by reactive oxygen species (ROS) and reactive nitrogen species (RNS) plays a pivotal role. It is widely accepted that diabetes impairs endothelial nitric oxide synthase (eNOS) activity and increases the production of ROS, thus resulting in diminished NO bioavailability and increased oxidative stress. Alpha-lipoic acid (LA) possesses beneficial effects both in the prevention and …
Omega-3 Extraction from Anchovy Fillet Leftovers with Limonene: Chemical, Economic, and Technical Aspects
2019
International audience; We investigate selected chemical, technical, and economic aspects of the production of fish oil rich in polyunsaturated omega-3 fatty acids from anchovy filleting leftovers using d-limonene as the extraction solvent at ambient temperature and pressure. Entirely derived from the orange peel prior to orange squeezing for juice production, the bio-based solvent is easily recovered, affording a circular economy process with significant potential for practical applications.
Peroxydation in vivo et in vitro des acides gras polyinsaturés
2007
It is well admitted that polyunsaturated fatty acids are the most sensitive fatty acids to oxidative damage because of their high number of double bonds. This concept could not be confirmed by in vitro, animal, or human studies since unexpected or even contradictory results were obtained. The explanation of that is probably related to the methods evaluating lipid peroxidation whose relevance is not always established, but especially to movements of polyunsaturated fatty acids within lipoproteins that results in their protection. This short review aims to discuss the main results related to this topic.
TAURINE SUPPLEMENTATION PREVENTS HYPERAMINOACIDEMIA IN GROWING TERM INFANTS FED HIGH PROTEIN COW'S MILK FORMULA. † 1891
1996
Blood urea nitrogen (BUN) and plasma and urine amino acid concentrations were compared between three cohorts of healthy term infants who were breast-fed (BF) or randomly assigned to one of two formulas either taurine non-supplemented (FF) or taurine supplemented (FF+T). The formulas had a protein concentration of 2 g/dl (2.9 g/100 kcal) and a whey/casein ratio of 20/80. The infants were studied from 2 to 12 weeks of age. Weight gain and growth in length was normal and similar in all three feeding groups during the study interval. At 12 weeks BUN was significantly higher in the FF group than in the BF and FF+T groups of infants, 16.5 mg/dl vs 7.0 and 7.3 mg/dl respectively. Total plasma amin…
Determination of fatty acids and lipid classes in salmon oil by near infrared spectroscopy
2017
International audience; Near-infrared (NIR) spectroscopy was evaluated as a rapid method for the determination of oleic, palmitic, linoleic and linolenic acids as well as omega-3, omega-6, and to predict polyunsaturated, monounsaturated and saturated fatty acids, together with triacylglycerides, diglycerides, free fatty acids and ergosterol in salmon oil. To do it, Partial Least Squares (PLS) regression models were applied to correlate NIR spectra with aforementioned fatty acids and lipid classes. Results obtained were validated in front of reference procedures based on high performance thin layer and gas chromatography. PLS-NIR has a good predictive capability with relative root mean squar…
Involvement of Lipoxygenase-dependent Production of Fatty Acid Hydroperoxides in the Development of the Hypersensitive Cell Death induced by Cryptoge…
1999
Lipid peroxidation was investigated in relation with the hypersensitive reaction in cryptogein-elicited tobacco leaves. A massive production of free polyunsaturated fatty acid (PUFA) hydroperoxides dependent on a 9-lipoxygenase (LOX) activity was characterized during the development of leaf necrosis. The process occurred after a lag phase of 12 h, was accompanied by the concomitant increase of 9-LOX activity, and preceded by a transient accumulation of LOX transcripts. Free radical-mediated lipid peroxidation represented 10% of the process. Inhibition and activation of the LOX pathway was shown to inhibit or to activate cell death, and evidence was provided that fatty acid hydroperoxides ar…
Effect of 18:3 n-3 geometrical isomers of heated linseed oll on the biosynthesis of arachidonic acid in rat
1990
Abstract The influence of dietary heated linseed oil on the fatty acid composition of rat liver, platelet and plasma phospholipids (PL) with particular reference to the metabolism of linoleic acid (18:2 n-6) were studied. Δ6 and Δ5 desaturase activities and fatty acid composition of hepatic microsomal total lipids (TL) also were determined. Two groups of male weanling rats were fed, for 6 weeks, diets containing 10% (in weight) of a fresh linseed oil (LO group) and of a heated linseed oil (HLO group). The contents of geometrical isomers of linolenic acid (18:3 n-3) were high in the oil heated at 240°C for 10 hours. The pattern of arachidonic acid (20:4 n-6) in the different lipid fractions …
Regulation of the activity of the Cholesteryl Ester Tranfer Protein (CETP) : electrostatics interactions with carboxylic derivatives (Non Esterified …
1997
In human plasma, the cholesteryl ester transfer protein (CETP) plays a key role in lipoprotein metabolism by promoting the net mass transfer of cholesteryl esters from HDL towards apoB-containing lipoproteins, and the transfer of triglycerides from VLDL towards HDL and LDL. Thus CETP arises as a potentially important factor in plasma lipoproteins metabolism, a statement which raised a considerable interest in identifying the factors which may regulate CETP activity.In our in vitro studies, we demonstrated that amphipathic molecules (non esterified fatty acids and retinoic acids) constituted of one carboxylic head group and one hydrophobic carbon chain are able to increase the cholesteryl es…
The mechanisms of the action of omega-3s in the retina
2013
Age-related Macular Degeneration (AMD) is the leading cause of visual loss in Western countries after the age of 50y. Based on large-scale epidemiologic studies, it appears now as evident that omega-3 polyunsaturated fatty acids (PUFAs) provide benefits in preventing both, early and late stages of AMD. The aim of this paper is to summarize the knowledge about the biological mechanisms by which omega-3 PUFAs may be protective for the retina. The content of this presentation will range from biochemical data about the occurrence of omega-3 PUFAs in retinal cell membranes to results from cellular and animal studies showing that omega-3 PUFAs can influence processes involved in signal transducti…
Lactacidemia en el umbral anaeróbico. Estudio en varones prepúberes de escuelas deportivas de fútbol.
2004
El objetivo principal es conocer la conducta del lactato en sangre.Situación bibliográfica.Estructurada en cinco apartados: reservas energéticas y límites metabólicos, la regulación ácido-base, el metabolismo del lactato, el umbral anaeróbico y las diferencias existentes entre niños y adultos. Nos centramos en los menores niveles de lacticemia en los niños, el mayor umbral anaeróbico en prepúberes frente a adultos y las diferencias de adaptación del metabolismo glucolítico.Material y métodos. Los criterios de selección de la población estudiada fueron: varones de 8-12 años, nivel socioeconómico medio, raza blanca, ausencia de limitaciones patológicas, volumen testicular menor o igual a 3 ml…