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Results 451 - 500 of 2619
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Okada Mitsuko - - 2003
Prolonged dietary restriction has been reported to suppress age-induced phenomena. In order to investigate how prolonged caloric restriction reduces age-related deterioration of hippocampal synaptic transmission, we compared the levels of major hippocampal polyunsaturated fatty acids, arachidonic acid and docosahexaenoic acid between 4- and 26-month-old rats. The Ca(2+) responses upon perfusion ...
Turgeon David - - 2003
Arachidonic acids (AA) and linoleic acids (LAs) are metabolized, in several tissues, to hydroxylated metabolites that are important mediators of many physiological and pathophysiological processes. The conjugation of leukotriene B4 (LTB4), 5-hydroxyeicosatetraenoic acid (HETE), 12-HETE, 15-HETE, and 13-hydroxyoctadecadienoic acid (HODE) by the human UDP-glucuronosyltransferase (UGT) enzymes was investigated. All substrates ...
Refaai M A - - 2003
The role of fatty acid ethyl esters (FAEE), the nonoxidative ethanol metabolites, as mediators of alcohol-induced organ damage is increasingly being recognized. FAEE are detectable in the blood and in liver and adipose tissue after ethanol ingestion, and on that basis, FAEE can be used as markers of ethanol intake. ...
Ayajiki Kazuhide - - 2003
We investigated mechanisms of endothelium-dependent relaxation by acetylcholine resistant to indomethacin and N(G)-nitro-L-arginine and sensitive to cytochrome P-450 (CYP) inhibitors or charybdotoxin + apamin in the monkey lingual artery. Treatment with quinacrine, an inhibitor of phospholipase A2, abolished the relaxation by acetylcholine. However, treatment with alpha-glycyrrhetinic acid, an inhibitor of ...
Miller P - - 2003
The human tandem P domain K+ channel hTREK-1 (KCNK2) is distributed widely through the CNS. Here, whole-cell patch clamp recordings were employed to investigate the effects of hypoxia on hTREK-1 channels stably expressed in human embryonic kidney cells. Acute hypoxia caused a rapid and reversible inhibition of whole-cell K+ current ...
Barbin Laura - - 2003
This study was undertaken in order to investigate the possible interactions between nitric oxide and arachidonic acid (AA) in Venus verrucosa oocytes. We perifused isolated oocytes to determine the effect of the following substances on [3H]arachidonic acid release ([3H]AA): (1) A 23187, a calcium ionophore; (2) nitric oxide (NO) donors; ...
Zarini Simona - - 2003
5-Oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE) is a metabolite of arachidonic acid shown to possess important biological activities within different cell types. In the neutrophil, a specific NADP(+)-dependent dehydrogenase utilizes 5-lipoxygenase-derived 5-hydroxy-6,8,11,14-eicosatetraenoic acid (5(S)-HETE) as the required substrate. In the present study, 5-hydroperoxy-6,8,11,14-eicosatetraenoic acid (5-HpETE), rather than 5-HETE, was found to be the ...
Ding Xian-Zhong - - 2003
The essential fatty acids, linoleic acid and arachidonic acid play an important role in pancreatic cancer development and progression. These fatty acids are metabolized to eicosanoids by cyclooxygenases and lipoxygenases. Abnormal expression and activities of both cyclooxygenases and lipoxygenases have been reported in pancreatic cancer. In this article, we aim ...
Miller Allison W - - 2003
We examined the mechanism of arachidonic acid-induced vasodilation in rat small mesenteric arteries and determined the primary arachidonic acid metabolites produced by these arteries. Responses to arachidonic acid in small mesenteric arteries from Sprague-Dawley rats were investigated in vitro in the presence or absence of endothelium or after pretreatment with ...
Zhu M - - 2003
The production of arachidonic acid was studied in the fungus Mortierella alpina using an inexpensive medium. Glucose derived from maize starch hydrolysate was the sole carbon source and defatted soybean meal and sodium nitrate were the nitrogen sources. Optimal arachidonic acid yield (1.47 g l(-1)) was observed at a glucose ...
Phillis J W - - 2002
Elevated levels of free fatty acids (FFA) have been implicated in the pathogenesis of neuronal injury and death induced by cerebral ischemia. This study evaluated the effects of immunosuppressants agents, calcineurin inhibitors and blockade of endoplasmic reticulum (ER) calcium channels on free fatty acid formation and efflux in the ischemic/reperfused ...
Werner K - - 2002
Cytochrome P450 metabolism of arachidonic acid (AA) was investigated in human peritoneal macrophages which play a central role in chronic pelvic diseases in women (for example in endometriosis). The formation of eicosanoids other than prostaglandins (PGs) by these cells is still unknown. In non-activated macrophages obtained from women in the ...
Oksala N K J - - 2002
BACKGROUND: Superficial mucosal injury is repaired immediately by a process known as restitution, which is controlled by several factors and is based on cellular migration. Heat-shock preconditioning increases the tolerance of tissue to deep gastric mucosal injury via synthesis of heat-shock proteins. Despite immediate positive effects on the tissue, we ...
VanderNoot Victoria A - - 2002
The essential fatty acid arachidonate is oxidized by cytochrome P-450 epoxygenases to four epoxyeicosatrienoic acids (EETs): 14,15-, 11,12-, 8,9-, and 5,6-EETs. Each of the four EET regioisomers and their hydrolysis products (DHETs) has multiple paracrine and autocrine functions and may also potently dilate blood vessels and activate potassium channels. The ...
Balsinde Jesús - - 2002
Phospholipase A(2) (PLA(2)) constitutes a growing superfamily of lipolytic enzymes, and to date, at least 19 distinct enzymes have been found in mammals. This class of enzymes has attracted considerable interest as a pharmacological target in view of its role in lipid signaling and its involvement in a variety of ...
Singh Digvijay - - 2002
Exposure of fish over 96 h to 40 and 80% of LC(50) (24 h) of aqueous latex extracts of Euphorbia royleana and Jatropha gossypifolia of family Euphorbiaceae significantly altered the level of total protein, total free amino acids, nucleic acids, pyruvate, lactate, glycogen and as well as protease activity also ...
Pilitsis J G - - 2002
Free fatty acid (FFA) elevation in the brain has been shown to correlate with the severity of damage in ischemic injury. The etiology of this increase in FFA remains unclear and has been hypothesized to result from phospholipase activation. This study examines the effects of specific phospholipase inhibitors on FFA ...
Lee Geon Young - - 2002
The effects of arachidonic acid on tetrodotoxin-sensitive (TTX-S) and tetrodotoxin-resistant (TTX-R) sodium currents in rat dorsal root ganglion neurons were assessed using the whole-cell patch-clamp method. Both sodium currents were modulated in a similar way by extracellular application of arachidonic acid. Arachidonic acid increased the currents at lower depolarizing potentials, ...
Seegers Hélène C - - 2002
The role of calcium-independent phospholipase A(2) (iPLA(2))-produced arachidonic acid (AA) in acetylcholine (ACh)-mediated, endothelium-dependent vascular relaxation was investigated. ACh-induced relaxation of phenylephrine-constricted isolated rat mesenteric resistance arteries was attenuated following pretreatment with (E)-6-(bromomethylene)tetrahydro-3-(1-naphthalenyl)-2H-pyran-2-one (BEL; 1 microM; p < 0.01), a highly selective suicide substrate inhibitor of iPLA(2). Following BEL, the ...
Mytilineou Catherine - - 2002
Oxidative stress is believed to contribute to the pathogenesis of Parkinson's disease. One of the indices of oxidative stress is the depletion of the antioxidant glutathione (GSH), which may occur early in the development of Parkinson's disease. To study the role of GSH depletion in the survival of dopamine neurons ...
Biondi C - - 2002
In order to clarify the possible interactions between nitric oxide (NO) and arachidonic acid (AA) pathways, human amnion-like WISH cells were perifused to measure the effects of the following substances on [(3)H]arachidonic acid release: (1) sodium nitroprusside (SNP), a nitric oxide donor; (2) 1,1,1-trifluoromethyl-6,9,12,15-heicosatetraen-2-one, a cytosolic phospholipase A(2) (cPLA(2)) inhibitor; ...
Schwarzer Evelin - - 2003
Plasmodium falciparum digests up to 75% of erythrocyte (red blood cell [RBC]) hemoglobin and forms hemozoin. Phagocytosed hemozoin and trophozoites inhibit important monocyte functions. Delipidized trophozoites and hemozoin were remarkably less toxic to monocytes. Parasitized RBCs and hemozoin contained large amounts of mostly esterified monohydroxy derivatives (OH-PUFAs), the stable end ...
Lefkowitz Lee J - - 2002
Sulfur mustard (2,2(')-dichloroethyl sulfide) is a chemical warfare agent that causes incapacitating skin blisters in humans 12-24h post-exposure following a variable asymptomatic phase. Recent reports demonstrate that inflammation plays a vital role in sulfur mustard toxicity. One of the key biochemical pathways involved in inflammation is the arachidonic acid cascade. ...
Liagre B - - 2002
We describe a model which can be used for in vitro biocompatibility assays of biomaterials. We studied the in vitro response of human osteoarthritis or rheumatoid arthritis fibroblast-like synoviocytes to Al2O3 or ZrO2 particles by analysing the production of interleukin-1 (IL-1) and interleukin-6 (IL-6) and the metabolism of arachidonic acid ...
Capdevila Jorge H - - 2002
The cytochrome P450 (P450) arachidonic acid (AA) monooxygenase metabolizes the fatty acid to a series of epoxy- and hydroxy-acid derivatives. Catalytic turnover requires NADPH, and requires the redox-coupled activation and cleavage of diatomic oxygen, and the delivery of an active form of atomic oxygen to ground state carbon atoms. Past ...
Kuhn Hartmut - - 2002
Lipoxygenases (LOXs) constitute a heterogeneous family of lipid peroxidizing enzymes capable of oxygenating polyunsaturated fatty acids to their corresponding hydroperoxy derivatives. In mammals, LOXs are classified with respect to their positional specificity of arachidonic acid oxygenation into 5-, 8-, 12-, and 15-LOXs. Arachidonate 15-LOXs may be sub-classified into a reticulocyte-type ...
Ueda Natsuo - - 2002
Endocannabinoids (endogenous ligands of cannabinoid receptors) such as anandamide (N-arachidonoylethanolamine) and 2-arachidonoylglycerol (2-AG) are inactivated upon enzymatic hydrolysis. Recent progress in the enzymological and molecular biological studies on the 'endocannabinoid hydrolases' is reviewed in this article. Anandamide is hydrolyzed to arachidonic acid and ethanolamine by a membrane-bound amidase generally referred ...
Cowart L Ashley - - 2002
Cytochromes P450 of the CYP2C and CYP4A gene subfamilies metabolize arachidonic acid to 5,6-, 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acids (EETs) and to 19- and 20-hydroxyeicosatetraenoic acids (HETEs), respectively. Abundant functional studies indicate that EETs and HETEs display powerful and often opposing biological activities as mediators of ion channel activity and ...
Ivanov Igor V - - 2002
(5Z,8Z,11Z,13E)-15-Hydroxy-5,8,11,13-eicosatetraenoic acid (15-HETE) is not well oxygenated by arachidonate 15-lipoxygenases because of two structural reasons: (i) it contains a hydrophilic OH-group in close proximity to its methyl end and (ii) it lacks the bisallylic methylene at C(13). We synthesized racemic (5Z,8Z,11Z,14Z)-16-hydroxy-5,8,11,14-eicosatetraenoic acid (16-HETE) which still contains the bisallylic C(13), separated ...
Schewe Tankred - - 2002
(-)-Epicatechin and its related oligomers, the procyanidins, are present in sizable amounts in some cocoas and chocolates. Intake of flavonoid-rich chocolate in humans has been reported to increase the plasma level of (-)-epicatechin and concomitantly to significantly decrease the plasma level of proinflammatory cysteinyl leukotrienes. Because leukotrienes are formed via ...
Rapoport Stanley I - - 2002
Lithium and certain anticonvulsants, including carbamazepine and valproic acid, are effective antimanic drugs for treating bipolar disorder, but their mechanisms of action remain uncertain. Feeding rats lithium chloride for 6 weeks, to produce a brain lithium concentration of 0.7mM, reduced arachidonic acid turnover within brain phospholipids by 75%. The effect ...
Hosoi Takeshi - - 2002
We have conducted an in silico data base search for and cloned a novel G-protein-coupled receptor (GPCR) named TG1019. Dot and Northern blotting analyses showed that transcripts of the novel GPCR were expressed in various tissues except brain, and the expression was more intense in liver, kidney, peripheral leukocyte, lung, ...
Beppu Masatoshi - - 2002
Arachidonic acid cascade inhibitors, including phospholipase A2 inhibitors, dexamethasone and quinacrine (mepacrine), cyclooxygenase inhibitors, indomethacin and aspirin, and lipoxygenase inhibitor AA861, prevented foam cell formation and cholesterol accumulation in the incubation of thioglycollate-induced mouse peritoneal macrophages with oxidized low density lipoprotein (LDL) at 37 degrees C for 24 h. These ...
Mîinea Cristinel - - 2002
In cultured Schwann cells, elevated glucose induces alterations in arachidonic acid metabolism that cause a decrease in the content of glycerophospholipid arachidonoyl-containing molecular species (ACMS). This could result from decreased de novo arachidonic acid biosynthesis, or increased arachidonic acid release from phospholipids. Incorporation of radioactive 8,11,14-eicosatrienoic acid into ACMS was ...
Kroetz Deanna L - - 2002
Cytochrome P450s metabolize arachidonic acid to hydroxyeicosatetraenoic acids and epoxyeicosatrienoic acids. These eicosanoids are formed in a tissue and cell-specific manner and have numerous biological functions. Of major interest are the opposing actions of hydroxyeicosatetraenoic and epoxyeicosatrienoic acids within the vasculature. Regio- and stereoisomeric epoxyeicosatrienoic acids have potent vasodilatory properties ...
Newaz Mohammad A - - 2002
Administration of glycerol produces acute renal failure (ARF) accompanied by profound vasoconstriction. It was hypothesized that impaired arachidonic acid metabolism may contribute to the vasoconstriction through alteration of renal eicosanoids or endothelin-1 or angiotensin II stimulation of renal oxygenases. Arachidonic acid (5, 10, 25 microg) in the control kidney produced ...
Howe Gregg A - - 2002
Oxylipins comprise a group of biologically active compounds whose structural diversity is generated by the coordinate action of lipases, lipoxygenases, and a group of cytochromes P450 that are specialized for the metabolism of hydroperoxy fatty acids. Research on oxylipins has focused mainly on the biosynthesis of the plant signaling molecule ...
Corda Daniela - - 2002
The lysophospholipids are integral components of the plasma membrane that have often been considered as side products of the phospholipase A2 (PLA2)-dependent production of arachidonic acid and the deacylation/reacylation processes involved in phospholipid homeostasis. Data indicating roles of these lipid derivatives in hormone responses and cell transformation have now led ...
Gauthier Kathryn M - - 2002
Endothelium-dependent hyperpolarization and relaxation of vascular smooth muscle are mediated by endothelium-derived hyperpolarizing factors (EDHFs). EDHF candidates include cytochrome P-450 metabolites of arachidonic acid, K(+), hydrogen peroxide, or electrical coupling through gap junctions. In bovine coronary arteries, epoxyeicosatrienoic acids (EETs) appear to function as EDHFs. A 14,15-EET analogue, 14,15-epoxyeicosa-5(Z)-enoic acid ...
Capdevila J H - - 2002
The demonstration of a role for microsomal P450 in the metabolism of endogenous pools of arachidonic acid established this enzyme system as a member of the arachidonic acid cascade and characterized a new an important metabolic function for this enzyme system. Studies from several laboratories documenting the powerful biological activities ...
Pohnert Georg - - 2002
The activation of oxylipin-based chemical defense in the diatom Thalassiosira rotula is initiated by phospholipases that act immediately after cell damage. This lipase activity is responsible for the preferential release of free mono- and polyunsaturated fatty acids. Among these, eicosatetraenoic- and eicosapentaenoic acid are further converted by lipoxygenases to reactive ...
Zabrodskii P F - - 2002
In vitro experiments on splenocytes from noninbred mice showed that ethylene glycol, methanol, and ethanol dose-dependently suppressed functional activity of T and B cells. These compounds in equimolar concentrations (10, 100, and 500 mM) produced similar effects, hence their immunotoxicity is determined by their metabolites. The suppressive effects of alcohol ...
Sugiura T - - 2002
N -arachidonoylethanolamine (anandamide) was the first endogenous cannabinoid receptor ligand to be discovered. Dual synthetic pathways for anandamide have been proposed. One is the formation from free arachidonic acid and ethanolamine, and the other is the formation from N -arachidonoyl phosphatidylethanolamine (PE) through the action of a phosphodiesterase. These pathways, ...
Hansen-Petrik Melissa B - - 2002
Arachidonic acid is an important polyunsaturated fatty acid involved in cell signaling. It is derived primarily from dietary linoleic acid, and the rate-limiting step in its biosynthesis is the initial desaturation of linoleic acid via Delta-6 desaturase. Evidence suggests that downstream metabolic products of arachidonic acid, e.g. prostaglandins, are involved ...
Kattah Luciene Rodrigues - - 2002
Crotoxin, the main toxin of Crotalus durissus terrificus venom, exerts its lethal effect by blocking neurotransmission at the neuromuscular junction level through a triphasic mechanism. This effect seems to depend on its phospholipasic activity, suggesting that the mechanism of neurotransmission blockage may be related to fatty acids release in specific ...
Maćkowiak Marzena - - 2002
Previous immunohistochemical studies have shown that c-Fos proteins induced by DOI, a 5-HT2A/2C agonist, are present in the population of cortical neurons, which are devoid of 5-HT2A receptors. A mechanism of the induction of c-Fos proteins expression by DOI is still unclear. However, the involvement of the 5-HT2A and AMPA, ...
Eberhard Jörg - - 2002
Although the interactions of bacteria with keratinocytes induce the synthesis of various mediators, the capability of epithelial cells to form arachidonic acid mediators has not been studied, and therefore the first part of this study was initiated. The complex mixture of epithelium-derived mediators suggests that chemoattraction is not their only ...
Noverr Mairi C - - 2002
These studies demonstrate that pathogenic fungi (dermatophytic, subcutaneous, and systemic) have the ability to produce eicosanoids both from simple metabolites and from arachidonic acid. Host-derived eicosanoids have been previously demonstrated to enhance fungal colonization and atopic disease development. Thus, fungus-derived eicosanoids represent a potential class of novel virulence factors.
Wang C T - - 2001
Arachidonic acid release is an important regulatory component of uterine contraction and parturition, and previous studies showed that lindane stimulates arachidonic acid release from myometrium. The present study partially characterized the enzyme activity responsible for lindane-induced arachidonic acid release in myometrial cells. Lindane released arachidonic acid from cultured rat myometrial ...
Kulkarni A P - - 2001
Lipoxygenase, a member of the arachidonate cascade enzymes, dioxygenates polyenoic fatty acids to finally yield products with profound and distinct biological activity. This review summarizes the available evidence for another role played by lipoxygenases in the metabolism of endobiotics and xenobiotics. Although other mechanisms exist, a direct hydrogen abstraction by ...
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