Search Results
Results 401 - 450 of 2619
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Le Quéré Valérie - - 2004
CYP4F isoforms are involved in the oxidation of important cellular mediators such as leukotriene B4 (LTB4) and prostaglandins. The proinflammatory agent LTB4 and cytotoxic leukotoxins have been associated with several inflammatory diseases. We present evidence that the hydroxylation of Z 9(10)-epoxyoctadecanoic, Z 9(10)-epoxyoctadec-Z 12-enoic, and Z 12(13)-epoxyoctadec-Z 9-enoic acids and ...
Amemiya Tsugio - - 2004
PURPOSE: The purpose of this study was to demonstrate fatty acids in the rat retina and to show that time-of-flight secondary ion mass spectrometry (TOF-SIMS) can replace histochemistry. METHODS: Five normal 3-month-old Wistar Kyoto rats were used. The eyes were enucleated under pentobarbital anesthesia, immediately put into liquid nitrogen without ...
Garcia Eloi S - - 2004
Hemocoelic inoculation of epimastigotes of Trypanosoma rangeli strain H14 into 5th-instar larvae of Rhodnius prolixus previously fed on blood containing the same parasites, showed reduced number of hemocyte microaggregates in the hemolymph, enhanced number of flagellates in the hemolymph as well as increased mortality of these insects. All these effects ...
Cui Xiaoxuan - - 2004
OBJECTIVE: Sepsis is characterized by an early, hyperdynamic phase and a late, hypodynamic phase. Although studies have shown that cytochrome P450 (CYP) plays an important role in the regulation of vascular reactivity, alterations of vascular CYP isoforms in sepsis remain unknown. Since CYP2C11 and CYP2J4 convert arachidonic acid to vasodilative ...
DeLozier Tracy C - - 2004
The human CYP2Cs have been studied extensively with respect to the metabolism of clinically important drugs and endogenous chemicals such as arachidonic acid (AA). Five members of the mouse CYP2C family have previously been described that metabolize arachidonic acid into regio- and stereospecific epoxyeicosatrienoic acids (EETs) and hydroxyeicosatetraenoic acids, which ...
Sarkis Albert - - 2004
PURPOSE OF REVIEW: Cytochrome P-450 metabolites of arachidonic acid have been reported to play an important role in the control of renal function and vascular tone, and in the long-term control of arterial pressure. In this regard, 20-hydroxyeicosatetraenoic acid is a potent vasoconstrictor that inhibits sodium reabsorption in the kidney. ...
McCowen Karen C - - 2004
Despite absence of essential fatty acid deficiency (EFAD), increases in arachidonic acid to linoleic acid ratios occur in serum phospholipid of patients treated with chronic total parenteral nutrition (TPN). The parenteral lipid component of TPN contains abundant linoleate; thus low phospholipid linoleate may reflect increased conversion to arachidonate. Arachidonic acid ...
Roy Uzzal - - 2004
Trans-arachidonic acids (trans-AA) are products of cis-trans isomerization of arachidonic acid by nitrogen dioxide radical (NO(2)), and occur in vivo, but their metabolism is unknown. We found that hepatic microsomes oxidized trans-AA via cytochrome P450/NADPH system to epoxides, which were hydrolyzed by epoxide hydrolase to diols (DiHETEs). 14,15-trans-AA produced one ...
Vance Russell E RE Department of Microbiology and Molecular Genetics, Center for Genomic Applications and Therapeutics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, - - 2004
In mammals, lipoxygenases play key roles in inflammation by initiating the transformation of arachidonic acid into potent bioactive lipid mediators such as leukotrienes and lipoxins. In general, most bacteria are believed to lack lipoxygenases and their polyunsaturated fatty acid substrates. It is therefore of interest that an ORF (PA1169) with ...
Leslie Christina C - - 2004
Mammalian cells have developed specific pathways for the incorporation, remodeling, and release of arachidonic acid. Acyltransferase and transacylase pathways function to regulate the levels of esterified arachidonic acid in specific phospholipid pools. There are several distinct, differentially regulated phospholipases A2 in cells that mediate agonist-induced release of arachidonic acid. These ...
Nakamura Hiroyuki - - 2004
Sphingolipid metabolites such as sphingosine 1-phosphate (S1P) and ceramide can mediate many cellular events including apoptosis, stress responses and growth arrest. Although ceramide stimulates arachidonic acid metabolism in several cells, the effects of sphingosine and its endogenous analogs have not been established. We investigated the effects of D-erythro-sphingosine and its ...
Yang M S - - 2004
Abstract Metabolomic analysis is a technology which seeks to provide a comprehensive profile of all the metabolites present in a biological sample ( Fiehn 2002 ; Noguchi et al. 2003 ; Watkins et al. 2002 ). Metabolomics is not a new science, but emerging as an exciting application which can ...
Kramer Brian C - - 2004
The contribution of arachidonic acid (AA) release and metabolism to the toxicity that results from glutathione (GSH) depletion was studied in rat mesencephalic cultures treated with the GSH synthesis inhibitor l-buthionine sulfoximine. Our data show that GSH depletion is accompanied by increased release of AA, which is phosholipase A2 (PLA2) ...
Zhu M - - 2004
AIMS: To develop a fast isolation method for arachidonic acid-producing fungi of high yield. METHODS AND RESULTS: Relation between the staining degree of mycelia of Mortierella alpina stained with triphenyltetrazolium chloride (TTC) and arachidonic acid content in the fungal lipids was investigated. Results showed that staining degree of mycelia stained ...
Dymkowska Dorota - - 2004
The unsaturated fatty acids oleic acid and arachidonic acid induced typical apoptosis in Ehrlich ascites tumor cells harvested at the stationary growth phase. Arachidonic acid was a more potent inducer than oleic acid. Apoptosis was induced by concentrations of oleic and arachidonic acids that produced only partial uncoupling of the ...
Gauthier Kathryn M - - 2004
Arachidonic acid induces an endothelium-dependent relaxation of the rabbit aorta that is blocked by lipoxygenase inhibitors. The cellular vasodilatory mechanisms activated by arachidonic acid metabolites remain undefined. In rabbit thoracic aortic rings pretreated with indomethacin (10 micromol/L) and contracted with phenylephrine, arachidonic acid (0.1 to 100 micromol/L) induced concentration-dependent relaxations. ...
Li Quanxi - - 2004
The 12/15-lipoxygenases (12/15-LOX) catalyze the stereo-specific oxygenation of arachidonic and linoleic acids into a complex series of signaling molecules, including the hydroxyeicosatetraenoic acids (HETEs) and hydroxyoctadecadienoic acids (HODEs). Our previous studies, using high density oligonucleotide microarrays, suggested a novel link between progesterone receptor (PR) signaling and 12/15-LOX-mediated fatty acid metabolism ...
Nakashima Satoru - - 2003
sPLA(2)s (secretory phospholipases A(2)) belong to a broad and structurally diverse family of enzymes that hydrolyse the sn -2 ester bond of glycerophospholipids. We previously showed that a secreted fungal 15 kDa protein, named p15, as well as its orthologue from Streptomyces coelicolor (named Scp15) induce neurite outgrowth in PC12 ...
Feinmark Steven J - - 2003
Arachidonic acid metabolites have been proposed as signaling molecules in hippocampal long-term potentiation (LTP) and long-term depression (LTD) for >15 years. However, the functional role of these molecules remains controversial. Here we used a multidisciplinary biochemical, electrophysiological, and genetic approach to examine the function of the 12-lipoxygenase metabolites of arachidonic ...
Chuang Samuel S - - 2004
Long chain fatty acids have recently emerged as critical signaling molecules in neuronal, cardiovascular, and renal processes, yet little is presently known about the precise mechanisms controlling their tissue distribution and bioactivation. We have identified a novel cytochrome P450, CYP2U1, which may play an important role in modulating the arachidonic ...
Pfister Sandra L - - 2003
Previous work showed that rabbit aorta metabolizes arachidonic acid via 15-lipoxygenase to 15-hydroperoxyeicosatetraenoic acid (15-HPETE), which undergoes an enzymatic rearrangement to 11-hydroxy-14,15-epoxyeicosatrienoic acid (11-H-14,15-EETA) and 15-hydroxy-11,12-epoxyeicosatrienoic acid (15-H-11,12-EETA). Hydrolysis of the epoxy group results in the formation of 11,14,15- and 11,12,15-trihydroxyeicosatrienoic acids (THETAs). Endothelial cells have several heme-containing enzymes including ...
Xu Fengyun - - 2004
Arachidonic acid is omega-hydroxylated to 20-hydroxyeicosatetraenoic acid (20-HETE), which has effects on vasoactivity and renal tubular transport and has been implicated in the regulation of blood pressure. Cytochrome p450 (p450) 4A isoforms are generally considered the major arachidonic acid omega-hydroxylases; however, little is known about the role of rat CYP4F ...
Saitoh Masaru - - 2003
The present study aimed at understanding the effects of arachidonic acid peroxides on neuronal cell death using the mouse neuroblastoma cell line, Neuro-2A cells. Arachidonic acid peroxides were produced by ultraviolet (UV) radiation. UV-radiated arachidonic acid significantly reduced Neuro-2A cell viability at concentrations of more than 0.1 muM, with being ...
Kaduce Terry L - - 2004
We have investigated the role of endothelial cells in the metabolism of 20-hydroxyeicosatetraenoic acid (20-HETE), a vasoactive mediator synthesized from arachidonic acid by cytochrome P450 omega-oxidases. Porcine coronary artery endothelial cells (PCEC) incorporated 20-[(3)H]HETE primarily into the sn-2 position of phospholipids through a coenzyme A-dependent process. The incorporation was reduced ...
Jones Raymond - - 2003
Colorectal carcinoma is a leading cause of cancer related death worldwide. This deadly disease advances through a series of clinical and histopathological stages, initiated by single crypt lesions to small benign tumors and finally to malignancy. Although some progress has been made in elucidating the formation of colorectal tumors at ...
Miller Paula - - 2004
Expression of the human tandem P domain K+ channel, hTREK1, is limited almost exclusively to the central nervous system, where ambient Po2 can be as low as 20 Torr. We have previously shown that this level of hypoxia evokes a maximal inhibitory influence on recombinant hTREK1 and occludes the activation ...
Danthi S - - 2003
The modulation of TREK-1 leak and Kv1.4 voltage-gated K+ channels by fatty acids and lysophospholipids was studied in bovine adrenal zona fasciculata (AZF) cells. In whole-cell patch-clamp recordings, arachidonic acid (AA) (1-20 microM) dramatically and reversibly increased the activity of bTREK-1, while inhibiting bKv1.4 current by mechanisms that occurred with ...
Sacerdoti David - - 2003
Arachidonic acid (AA) can undergo monooxygenation or epoxidation by enzymes in the cytochrome P450 (CYP) family in the brain, kidney, lung, vasculature, and the liver. CYP-AA metabolites, 19- and 20-hydroxyeicosatetraenoic acids (HETEs), epoxyeicosatrienoic acids (EETs) and diHETEs have different biological properties based on sites of production and can be stored ...
Faas F H - - 2003
OBJECTIVE: To measure prostatic and blood fatty acid composition in a large group of patients undergoing prostatectomy for benign or malignant prostate disease, as there is evidence linking arachidonic acid metabolism and prostate cancer through its role as an eicosanoid precursor, and earlier studies showed lower prostatic arachidonic acid content ...
Levine Lawrence - - 2003
Tamoxifen is widely prescribed for the treatment of breast cancer. Its success has been attributed to the modulation of the estrogen receptor. I have previously proposed that the release of arachidonic acid from cells may also mediate cancer prevention. Rat liver cells were radiolabelled with arachidonic acid. The release of ...
Gauthier Kathryn M - - 2003
Endothelium-dependent hyperpolarizations and relaxation of vascular smooth muscle induced by acetylcholine and bradykinin are mediated by endothelium-derived hyperpolarizing factors (EDHFs). In bovine coronary arteries, arachidonic acid metabolites, epoxyeicosatrienoic acids (EETs), function as EDHFs. The 14,15-EET analog 14,15-epoxyeicosa-5(Z)-enoic-methylsulfonylimide (14,15-EEZE-mSI) was synthesized and tested for agonist and antagonist activity. In U46619-preconstricted bovine ...
Okita Misako - - 2003
OBJECTIVES: An abnormal fatty acid pattern in patients with advanced liver cirrhosis (LC) has been reported in plasma phospholipids and some other tissues. To elucidate the significance of arachidonic acid deficiency on the clinical pathophysiology of LC and hepatocellular carcinoma (HCC), we analyzed the fatty acid compositions of mononuclear cell ...
Pérez-Matute P - - 2003
Leptin, a hormone produced in adipocytes, is a key signal in the regulation of food intake and energy expenditure. Several studies have suggested that leptin can be regulated by macronutrients intake. Arachidonic acid is a dietary fatty acid known to affect cell metabolism. Controversial effects of this fatty acid on ...
Vogan Claire L - - 2003
The barnacle life cycle has two key stages at which eicosanoids are believed to be involved in cellular communication pathways, namely the hatching of nauplii and the settlement of cypris larvae. Barnacle egg-hatching activity has previously been reported to reside in a variety of eicosanoids, including 8-hydroxyeicosapentaenoic acid and a ...
Tang Xin - - 2003
OBJECTIVE: Vasorelaxation of rabbit aorta is mediated by factors released from the vascular endothelium. In the aortic endothelium, arachidonic acid (AA) is metabolized via the 15-lipoxygenase pathway to the vasodilatory compounds 11,12,15-trihydroxyeicosatrienoic acid (THETA) and 15-hydroxy-11,12-epoxyeicosatrienoic acid (HEETA). Interleukin-13 (IL-13) increases 15-lipoxygenase expression and activity in several types of cells. ...
Pomposiello Silvia I - - 2003
We have shown a cytochrome P450-dependent renal vasodilator effect of arachidonic acid in response to inhibition of cyclooxygenase and elevation of perfusion pressure, which was enhanced in the spontaneously hypertensive rat (SHR) and linked to increased production of and/or responsiveness to epoxyeicosatrienoic acids (EETs). In the SHR, vasodilation elicited by ...
Petersen Rasmus K - - 2003
Arachidonic acid inhibits adipocyte differentiation of 3T3-L1 cells via a prostaglandin synthesis-dependent pathway. Here we show that this inhibition requires the presence of a cAMP-elevating agent during the first two days of treatment. Suppression of protein kinase A activity by H-89 restored differentiation in the presence of arachidonic acid. Arachidonic ...
Akakabe Yoshihiko - - 2003
Marine green alga Ulva conglobata was investigated for the biogeneration of oxygenated products from exogenously added arachidonic acid (ARA). A crude enzyme from the alga afforded the detectable amount of a hydroperoxyicosatetraenoic acid (HPITE), which was identified as (R)-11-HPITE by HPLC and GC-MS. Headspace-SPME method indicated that ARA was selectively ...
Tanaka E - - 2003
Intracellular recordings were made from hippocampal CA1 neurons in rat slice preparations. Superfusion with oxygen- and glucose-deprived medium (in vitro ischemia) produced a rapid depolarization approximately 5 min after the onset of the superfusion. Even when oxygen and glucose were reintroduced immediately after rapid depolarization, the membrane depolarized further (persistent ...
Campbell William B - - 2003
Rabbit aortic endothelium metabolizes arachidonic acid (AA) by the 15-lipoxygenase pathway to vasodilatory eicosanoids, hydroxyepoxyeicosatrienoic acids (HEETAs), and trihydroxyeicosatrienoic acids (THETAs). The present study determined the chemical identity of the vasoactive THETA and investigated its role in ACh-induced relaxation in the rabbit aorta. AA caused endothelium-dependent, concentration-related relaxations of the ...
Chattopadhyay Sandip - - 2003
Annexin II has been implicated in membrane fusion during the exocytosis of lamellar bodies from alveolar epithelial type II cells. Most previous studies were based on the fusion assays by using model membranes. In the present study, we investigated annexin II-mediated membrane fusion by using isolated lamellar bodies and plasma ...
Carattino Marcelo D - - 2003
Epithelial Na+ channels (ENaCs) are regulated by the phospholipase A2 (PLA2) product arachidonic acid. Pharmacological inhibition of PLA2 with aristolochic acid induced a significant increase in amiloride-sensitive currents in Xenopus oocytes expressing ENaC. Arachidonic acid or 5,8,11,14-eicosatetraynoic acid (ETYA), a non-metabolized analog of arachidonic acid, induced a time-dependent inhibition of ...
Boonprab Kangsadan - - 2003
In higher plants, C6 and C9 aldehydes are formed from C18 fatty acids, such as linoleic or linolenic acid, through formation of 13- and 9-hydroperoxides, followed by their stereospecific cleavage by fatty acid hydroperoxide lyases (HPL). Some marine algae can also form C6 and C9 aldehydes, but their precise biosynthetic ...
Pfister Sandra L - - 2003
Arachidonic acid is metabolized by both the cyclooxygenase and lipoxygenase pathways by rabbit aorta. We investigated the metabolism of 12-hydroperoxyeicosatetraenoic acid by aortic homogenates and microsomes. Rabbit aortic homogenates were incubated in the presence of (14)C-arachidonic acid plus 12-lipoxygenase and analyzed by reversed-phase high-pressure liquid chromatography (HPLC). Under these experimental ...
Pompeia Celine - - 2003
Arachidonic acid is a polyunsaturated fatty acid that mediates inflammation and the functioning of several organs and systems either directly or upon its conversion into eicosanoids. However, arachidonic acid is found to be cytotoxic in vitro at concentrations that overlap physiological ones. It is tempting therefore to speculate that arachidonic ...
Han Won K - - 2003
Oxidant stress and phospholipase A2 (PLA2) activation have been implicated in numerous proinflammatory responses of the mesangial cell (MC). We investigated the cross-talk between group IValpha cytosolic PLA2 (cPLA2alpha) and secretory PLA2s (sPLA2s) during H2O2-induced arachidonic acid (AA) release using two types of murine MC: (i). MC+/+, which lack group ...
Tanaka Tamotsu - - 2003
It is known that phosphatidylinositol (PtdIns) contains abundant arachidonate and is composed mainly of 1-stearoyl-2-arachidonoyl species in mammals. We investigated if this characteristic of PtdIns applies to the PtdIns from yellowtail (Seriola quinqueradiata), a marine fish. In common with phosphatidylcholine (PtdCho), phosphatidylethanolamine (PtdEtn) and phosphatidylserine (PtdSer) from brain, heart, liver, ...
Siomboing X - - 2003
The inflammatory process can be influenced by an enzyme known as cyclooxygenase, which exists in two isoforms: COX-1, the constitutive form, and COX-2, which is only synthesized in the case of inflammation and has negative side effects. To decrease these undesirable effects, current research seeks to discover compounds that selectively ...
Natarajan Rama - - 2003
Renal vascular effects of cyclooxygenase and cytochrome P450 metabolites of arachidonic acid have been extensively studied, with major advances having been made. More recently, studies indicate that arachidonic acid metabolites of the lipoxygenase and cytochrome P450 pathway, such as hydroxyeicosatetraenoic acids and epoxyeicosatrienoic acids, play novel roles in glomerular mesangial ...
Zosmer A - - 2003
Human trophoblast cells are known to release a range of arachidonic acid metabolites into culture medium, including cyclo-oxygenase, lipoxygenase and epoxygenase products. In this study we investigated the effects of dibutyryl cyclic AMP (db cAMP) on arachidonic acid metabolism in human first trimester trophoblast cells, and also determined the distribution ...
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