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Results 251 - 300 of 2634
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Rådmark Olof - - 2009
5-lipoxygenase (5-LO) catalyzes two steps in biosynthesis of leukotrienes (LTs), a group of lipid mediators of inflammation derived from arachidonic acid (AA). LT antagonists are used in treatment of asthma; more recently a potential role also in atherosclerosis has raised considerable interest. Furthermore, possible effects of 5-LO metabolites in relation ...
Spector Arthur A - - 2009
Cytochrome P450 (CYP) epoxygenases convert arachidonic acid to four epoxyeicosatrienoic acid (EET) regioisomers, 5,6-, 8,9-, 11,12-, and 14,15-EET, that function as autacrine and paracrine mediators. EETs produce vascular relaxation by activating smooth muscle large-conductance Ca2+-activated K+ channels (BKCa). In addition, they have anti-inflammatory effects on blood vessels and in the ...
Sanchez-Mejia Rene O RO Gladstone Institute of Neurological Disease, San Francisco, California 94158, USA. - - 2008
Neuronal expression of familial Alzheimer's disease-mutant human amyloid precursor protein (hAPP) and hAPP-derived amyloid-beta (Abeta) peptides causes synaptic dysfunction, inflammation and abnormal cerebrovascular tone in transgenic mice. Fatty acids may be involved in these processes, but their contribution to Alzheimer's disease pathogenesis is uncertain. We used a lipidomics approach to ...
Liu Xuebo - - 2008
Oxidative stress appears to be directly involved in the pathogenesis of the neurodegeneration of dopaminergic systems in Parkinson disease. In this study, we formed four dopamine modification adducts derived from docosahexaenoic acid (C22:6/omega-3) and arachidonic acid (C18:4/omega-6), which are known as the major polyunsaturated fatty acids in the brain. Upon ...
Aggarwal Nitin T NT Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, - - 2008
Arachidonic acid (AA) metabolites from 15-lipoxygenase-1 (15-LO-1), trihydroxyeicosatrienoic acid (THETA), and hydroxyepoxyeicosatrienoic acid (HEETA) relax arteries. We studied 15-LO-1 expression, THETA and HEETA synthesis, and their effect on arterial relaxations and blood pressure in hypercholesterolemic nonatherosclerotic rabbits. Immunoblots, RTPCR analysis, and (14)C-AA metabolism revealed that hypercholesterolemia increased 15-LO-1 expression in ...
Jacquot Cyril C Department of Chemistry, Roger Adams Laboratory, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, IL 61801, - - 2008
Lipoxygenases catalyse the oxidation of polyunsaturated fatty acids and have been invoked in many diseases including cancer, atherosclerosis and Alzheimer's disease. Currently, no X-ray structures are available with substrate or substrate analogues bound in a productive conformation. Such structures would be very useful for examining interactions between substrate and active ...
Stebulis Judith A - - 2008
AIMS: To better understand mechanisms whereby Ajulemic acid (AjA), a synthetic antiinflammatory cannabinoid, promotes resolution of acute and chronic inflammation in animal models, we investigated its influence on cyclooxygenase 2 (COX2) expression and eicosanoid production in human fibroblast-like synovial cells (FLS). MAIN METHODS: FLS isolated from tissue obtained at joint ...
Zhou Qi - - 2008
Prostacyclin, synthesized from arachidonic acid, is a strong vasodilator and the most powerful inhibitor known for platelet aggregation. Magnesium deficiency as a risk factor for cardiovascular diseases was related to imbalance of thromboxane and prostacyclin in the vasculature. In this study, we examined the effect of a low level of ...
Kim Cheolmin - - 2008
Reactive oxygen species (ROS) are generated in mammalian cells via both enzymatic and non-enzymatic mechanisms. Although certain ROS production pathways are required for the performance of specific physiological functions, excessive ROS generation is harmful, and has been implicated in the pathogenesis of a number of diseases. Among the ROS-producing enzymes, ...
Zordoky Beshay N M - - 2008
Several cytochrome P450 (P450) enzymes have been identified in the heart, and their levels have been reported to be altered during cardiac hypertrophy. Moreover, there is a strong correlation between P450-mediated arachidonic acid metabolites and the pathogenesis of cardiac hypertrophy. Therefore, we investigated the effect of isoproterenol-induced cardiac hypertrophy on ...
Moreno Juan J - - 2009
Lipoxygenase (LOX) pathway leads to the formation of leukotrienes and also catalyses the conversion of arachidonic acid (AA) to hydroperoxyeicosatetraenoic acids that are then reduced to hydroxyeicosatetraenoic acids (HETE) by glutathione peroxidase. There are four mammalian LOXs that produce 5-, 8-, 12- and 15-HETE, respectively. Cytochrome P-450 isozymes are also ...
Mochizuki Kazuki - - 2008
It is reported that arachidonic acid strongly induces the conformational change in vitro and transactivity of PPAR alpha in colorectal cancer cell line Caco-2. In this study, we demonstrated that the induction of conformational change and transactivity of PPAR delta by arachidonic acid, as well as other polyunsaturated fatty acids, ...
Oliveira Vanessa H - - 2008
The intracellular level of long chain fatty acids controls the Ca(2+) concentration in the cytoplasm. The molecular mechanisms underlying this Ca(2+) mobilization are not fully understood. We show here that the addition of low micromolar concentrations of fatty acids directly to the purified plasma membrane Ca(2+)-ATPase enhance ATP hydrolysis, while ...
Gustafsson Sofia B - - 2009
Cannabinoids (CBs) have been found to exert antiproliferative effects upon a variety of cancer cells, including colorectal carcinoma cells. However, little is known about the signalling mechanisms behind the antitumoural effect in these cells, whether the effects are shared by endogenous lipids related to endocannabinoids, or whether such effects are ...
Chen Jian-Kang JK Department of Medicine, Vanderbilt University, Nashville, Tennessee 37232, - - 2008
Arachidonic acid is an essential constituent of cell membranes that is esterified to the sn-2-position of glycerophospholipids and is released from selected lipid pools by phospholipase cleavage. The released arachidonic acid can be metabolized by three enzymatic pathways: the cyclooxygenase pathway forming prostaglandins and thromboxanes, the lipoxygenase pathway generating leukotrienes ...
Wecksler Aaron T AT Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, - - 2008
Human reticulocyte 15-lipoxygenase (15-hLO-1) and epithelial 15-lipoxygenase (15-hLO-2) have been implicated in a number of human diseases, with differences in their substrate specificity potentially playing a central role. In this paper, we present a novel method for accurately measuring the substrate specificity of the two 15-hLO isozymes and demonstrate that ...
Jacquot Cyril C Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, - - 2008
Lipoxygenases (LOs) catalyze lipid peroxidation and have been implicated in a number of human diseases connected to oxidative stress and inflammation. These enzymes have also attracted considerable attention due to large kinetic isotope effects (30-80) for the rate-limiting hydrogen abstraction step with linoleic acid (LA) as substrate. Herein, we report ...
Balazy Michael - - 2008
A reaction of arachidonic acid with the nitrogen dioxide radical (*NO2) or its precursors (peroxynitrite, nitrous acid, nitrogen trioxide) generates a group of nitro lipids named nitroeicosanoids. A distinct feature of this reaction is abundant formation of four trans isomers of arachidonic acid (TAA) via reversible addition of the NO2 ...
Lombardi Assunta - - 2008
Mitochondrial uncoupling protein 3 (UCP(3))-mediated uncoupling has been postulated to depend on several factors, including superoxides, free fatty acids (FFAs), and fatty acid hydroperoxides and/or their derivatives. We investigated whether there is an interrelation between endogenous mitochondrial superoxides and fatty acids in inducing skeletal muscle mitochondrial uncoupling, and we speculated ...
Davidson Michael H - - 2008
The digestive tract plays a key role in lipid metabolism and in cardiovascular risk through the physiology of bile acids on lipid absorption, enterohepatic recycling of bile acids, and cholesterol oxidation in synthesis of bile acids. Recent evidence associates the activation of farnesoid X receptor by bile acids with alterations ...
Turman Melissa V MV A. B. Hancock, Jr. Memorial Laboratory for Cancer Research, Department of Biochemistry, Vanderbilt Institute of Chemical Biology, and Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146, - - 2008
A novel class of lipids, N-acyltaurines, was recently discovered in fatty acid amide hydrolase knockout mice. In some peripheral tissues, such as liver and kidney, N-acyltaurines with long, polyunsaturated acyl chains are most prevalent. Polyunsaturated fatty acids are converted to a variety of signaling molecules by cyclooxygenases (COXs) and lipoxygenases ...
Gaposchkin Daniel P - - 2008
We examined the dependence of stimulated arachidonic acid release on plasmalogens using the murine, macrophage cell line 264.7 and two plasmalogen-deficient variants, RAW.12 and RAW.108. All three strains responded to unopsinized zymosan to release arachidonic acid from phospholipid stores. Arachidonic acid release appeared to be dependent on calcium-independent phospholipase A(2) ...
Cossette Chantal - - 2008
Sebaleic acid (5,8-octadecadienoic acid) is the major polyunsaturated fatty acid in human sebum and skin surface lipids. The objective of the present study was to investigate the metabolism of this fatty acid by human neutrophils and to determine whether its metabolites are biologically active. Neutrophils converted sebaleic acid to four ...
Russell Wendy R - - 2008
Elevated levels of phospholipases, prostaglandin synthases and lipoxygenases in colonic cells at various stages of malignancy indicate a strong link between dietary lipids and colon cancer. Lipoxygenase-catalysed arachidonic acid metabolism plays a key role in colorectal carcinogenesis and has the potential to be modulated by phenolic compounds. Plant-based foods are ...
Jordan Janeen R - - 2008
Mesenteric lymph is the mechanistic link between splanchnic hypoperfusion and acute lung injury (ALI), but the culprit mediator(s) remains elusive. Previous work has shown that administration of a phospholipase A(2) (PLA(2)) inhibitor attenuated postshock ALI and also identified a non-ionic lipid within the postshock mesenteric lymph (PSML) responsible for polymorphonuclear ...
Tanka-Salamon Anna - - 2008
Thrombi, which are dissolved primarily by plasmin (EC 3.4.21.7.), contain up to millimolar concentrations of fatty acids and these are known to affect the action of the protease. In the present study the modulation of plasmin activity was characterized quantitatively in a continuous amidolytic assay based on synthetic plasmin substrate ...
Martin Diana - - 2008
The effect of replacing pork fat in liver pâtés by an enriched conjugated linoleic acid oil (CLA-pâté), olive oil (OO-pâté), or the combination of both type of oils (CLA+OO-pâté) on the fatty acid profile, lipid oxidative stability, consistency and emulsion stability was studied and compared with a traditional liver pâté ...
Hou Ching T - - 2008
The filamentous fungi of the genus Mortierella are known to produce arachidonic acid from glucose, and the species alpina is currently used in industrial production of arachidonic acid in Japan. In anticipation of a large excess of the co-product glycerol from the national biodiesel program, we are trying to find ...
Chawengsub Yuttana - - 2008
Arachidonic acid (AA) causes endothelium-dependent smooth muscle hyperpolarizations and relaxations that are mediated by a 15-lipoxygenase-I (15-LO-I) metabolite, 11,12,15-trihydroxyeicosatrienoic acid (11,12,15-THETA). We propose that AA is metabolized sequentially by 15-LO-I and hydroperoxide isomerase to an unidentified hydroxyepoxyeicosatrienoic acid (HEETA), which is hydrolyzed by a soluble epoxide hydrolase (sEH) to 11,12,15-THETA. ...
Feltenmark Stina - - 2008
Human eosinophils contain abundant amounts of 15-lipoxygenase (LO)-1. The biological role of 15-LO-1 in humans, however, is unclear. Incubation of eosinophils with arachidonic acid led to formation of a product with a UV absorbance maximum at 282 nm and shorter retention time than leukotriene (LT)C4 in reverse-phase HPLC. Analysis with ...
Fleming Ingrid - - 2008
Cytochrome P450 epoxygenases and the soluble epoxide hydrolase are enzymes that regulate the cellular content of bioactive epoxides such as the epoxyeicosatrienoic acids derived from arachidonic acid. Epoxyeicosatrienoic acids are recognized as lipid mediators that participate in vascular signaling processes such as the acute regulation of vascular tone and the ...
Gauthier Kathryn M - - 2007
Continuing investigations of the roles of cytochrome P450 (CYP) arachidonic acid epoxygenase metabolites in the regulation of cardiovascular physiology and pathophysiology have revealed their complex and diverse biological effects. Often these metabolites demonstrate protective properties that are revealed during cardiovascular disease. In this regard, the epoxyeicosatrienoic acids (EETs) are an ...
Kooli Amna - - 2008
Nitrative stress is an important regulator of vascular tone. We have recently described that trans-arachidonic acids (TAA) are major products of NO(2)(.)-mediated isomerization of arachidonic acid in cell membranes and that nitrative stress increases TAA levels leading to neural microvascular degeneration. In the present study, we explored whether TAA exert ...
Miyahara Takashige - - 2008
We previously reported that the cytosolic phospholipase A(2) (cPLA2) pathway is involved in ventilator-induced lung injury (VILI) produced by high peak inflation pressures (PIP) (J Appl Physiol 98: 1264-1271, 2005), but the relative contributions of the various downstream products of cPLA2 on the acute permeability response were not determined. Therefore, ...
Strauss Kenneth I KI Mayfield Neurotrauma Research Lab, Department of Neurosurgery, University of Cincinnati College of Medicine, 231 Albert Sabin Way, ML515, Cincinnati, OH 45267, USA. - - 2008
Overexpression of COX2 appears to be both a marker and an effector of neural damage after a variety of acquired brain injuries, and in natural or pathological aging of the brain. COX2 inhibitors may be neuroprotective in the brain by reducing prostanoid and free radical synthesis, or by directing arachidonic ...
Nieves Diana - - 2007
Previous studies have demonstrated that arachidonic acid (AA) metabolites released by the cyclooxygenase pathway is involved in serum-induced 3T6 fibroblast cycle progression and proliferation. However, these results also suggest that other AA cascade pathways might be involved. Recently, we also described the role of hydroxyeicosatetraenoic acids, which are produced by ...
Pawlas Natalia - - 2007
Release of arachidonic acid (AA) is a neurotoxic mechanism of oxidative nature in trauma and ischemia. We studied ebselen effects on AA and 4-hydroxynonenal toxicity in rat cortical neurons in simulated ischemia in vitro by assessing cell viability and glutathione concentration. Ebselen normalized neuronal viability diminished by AA and 4-hydroxynonenal ...
Larsen Brandon T BT Department of Pharmacology & Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Rd, Milwaukee, WI 53226, - - 2008
The cytochrome P450 epoxygenase (CYP)-derived metabolites of arachidonic acid the epoxyeicosatrienoic acids (EETs) and hydrogen peroxide (H2O2) both function as endothelium-derived hyperpolarizing factors (EDHFs) in the human coronary microcirculation. However, the relative importance of and potential interactions between these 2 vasodilators remain unexplored. We identified a novel inhibitory interaction between ...
Brock Thomas G - - 2008
Polyunsaturated fatty acids, like arachidonic acid, can bind proteins and affect their function. The 14-3-3 proteins bind phosphorylated sites on a diverse array of client proteins and, in this way, are involved in many intracellular signaling pathways. In this study, we used a novel approach to discover that 14-3-3zeta is ...
Yuhas Yael - - 2007
Rifampin, a potent antimicrobial agent, is a major drug in the treatment of tuberculosis. There is evidence that rifampin also serves as an immunomodulator. Based on findings that arachidonic acid and its metabolites are involved in the pathogeneses of Mycobacterium tuberculosis infections, we investigated whether rifampin affects prostaglandin E(2) (PGE(2)) ...
Theken Katherine N - - 2007
The cytochrome (CYP) P450 epoxygenase pathway catalyzes the epoxidation of arachidonic acids to epoxyeicosatrienoic acids, which are subsequently hydrolyzed to less active dihydroxyeicosatrienoic acids by soluble epoxide hydrolase. Numerous preclinical studies have demonstrated that CYP-derived epoxyeicosatrienoic acids possess potent vasodilatory and anti-inflammatory properties in the cardiovascular system. In humans, functionally ...
Gáti I - - 2007
The aim of this study was to elucidate the mechanisms of action for potential targets of therapeutic intervention related to the arachidonic acid cascade in muscular dystrophy. Primary cultures from a Duchenne patient were used to study the expression of dystrophin-1, utrophin, desmin, neonatal myosin heavy chain (MHCn) and Bcl-2 ...
Wichmann Oliver O European Molecular Biology Laboratorium, Gene Expression Programme, Meyerhofstrasse 1, 69117 Heidelberg, - - 2007
The Foerster resonance energy transfer-based sensor, PENN, measures intracellular phospholipase A(2) (PLA(2)) activity in living cells and small organisms. In an attempt to modify the probe for the detection of particular isoforms, we altered the sn-2 fatty acid in such a way that either one or three of the Z ...
Krajka-Ku┼║niak Violetta - - 2008
A simple plant phenolic acid, protocatechuic acid and a polyphenol, tannic acid are potential chemopreventive agents which inhibited the chemically induced carcinogenesis in many experimental models. We previously demonstrated that those compounds modulate the activity of xenobiotic detoxifying enzymes, including GST in mouse liver, kidney and epidermis. Intraperitoneal (i.p.) treatment ...
Sheldrick E Linda R - - 2007
Arachidonic acid is a potential paracrine agent released by the uterine endometrial epithelium to induce PTGS2 [PG (prostaglandin)-endoperoxide synthase 2] in the stroma. In the present study, bovine endometrial stromal cells were used to determine whether PTGS2 is induced by arachidonic acid in stromal cells, and to investigate the potential ...
Padma A Sai - - 2007
Arachidonic acid (AA) metabolism in the non-pregnant sheep uterus was studied in vitro using conventional chromatographic and HPLC techniques. High expression of both lipoxygenase (LOX) as well as cyclooxygenase (COX) enzymes and their activities was found in the uterine tissues. On incubation of uterine enymes with AA, the LOX products ...
Farooqui Akhlaq A - - 2007
The neural membranes contain phospholipids, sphingolipids, cholesterol, and proteins. Glycerophospholipids and sphingolipids are precursors for lipid mediators involved in signal transduction processes. Degradation of glycerophospholipids by phospholipase A(2) (PLA(2)) generates arachidonic acid (AA) and docosahexaenoic acids (DHA). Arachidonic acid is metabolized to eicosanoids and DHA is metabolized to docosanoids. The ...
Williams Jan Michael JM Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, - - 2007
This study examined the metabolism of arachidonic acid (AA) by cytochrome P-450 enzymes in isolated glomeruli and the effects of selective inhibitors of the synthesis of 20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatetraenoic acids (EETs) on glomerular permeability to albumin (P(alb)). Glomeruli avidly produced 20-HETE, EETs, dihydroxyeicosatetraenoic acids (diHETEs), and HETEs when ...
Cheng Z - - 2007
Second messenger signalling through cyclic AMP (cAMP) plays an important role in the response of the endometrium to prostaglandin (PG) E(2) during early pregnancy. Arachidonic acid, which is a by-product of the luteolytic cascade in ruminants, is a potential paracrine signal from the epithelium to the stroma. We investigated the ...
Hao Chuan-Ming - - 2007
Small lipids such as eicosanoids exert diverse and complex functions. In addition to their role in regulating normal kidney function, these lipids also play important roles in the pathogenesis of kidney diseases. Increased glomerular cyclooxygenase (COX)1 or COX2 expression has been reported in patients with nephritis and in animal models ...
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