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Sample records for l-name increases arachidonic

  1. Nitric oxide donors prevent while the nitric oxide synthase inhibitor L-NAME increases arachidonic acid plus CYP2E1-dependent toxicity

    SciTech Connect

    Wu Defeng; Cederbaum, Arthur . E-mail: arthur.cederbaum@mssm.edu

    2006-10-15

    Polyunsaturated fatty acids such as arachidonic acid (AA) play an important role in alcohol-induced liver injury. AA promotes toxicity in rat hepatocytes with high levels of cytochrome P4502E1 and in HepG2 E47 cells which express CYP2E1. Nitric oxide (NO) participates in the regulation of various cell activities as well as in cytotoxic events. NO may act as a protectant against cytotoxic stress or may enhance cytotoxicity when produced at elevated concentrations. The goal of the current study was to evaluate the effect of endogenously or exogenously produced NO on AA toxicity in liver cells with high expression of CYP2E1 and assess possible mechanisms for its actions. Pyrazole-induced rat hepatocytes or HepG2 cells expressing CYP2E1 were treated with AA in the presence or absence of an inhibitor of nitric oxide synthase L-N {sup G}-Nitroarginine Methylester (L-NAME) or the NO donors S-nitroso-N-acetylpenicillamine (SNAP), and (Z)-1-[-(2-aminoethyl)-N-(2-aminoethyl)]diazen-1-ium-1,2-diolate (DETA-NONO). AA decreased cell viability from 100% to 48 {+-} 6% after treatment for 48 h. In the presence of L-NAME, viability was further lowered to 23 {+-} 5%, while, SNAP or DETA-NONO increased viability to 66 {+-} 8 or 71 {+-} 6%. The L-NAME potentiated toxicity was primarily necrotic in nature. L-NAME did not affect CYP2E1 activity or CYP2E1 content. SNAP significantly lowered CYP2E1 activity but not protein. AA treatment increased lipid peroxidation and lowered GSH levels. L-NAME potentiated while SNAP prevented these changes. Thus, L-NAME increased, while NO donors decreased AA-induced oxidative stress. Antioxidants prevented the L-NAME potentiation of AA toxicity. Damage to mitochondria by AA was shown by a decline in the mitochondrial membrane potential (MMP). L-NAME potentiated this decline in MMP in association with its increase in AA-induced oxidative stress and toxicity. NO donors decreased this decline in MMP in association with their decrease in AA

  2. Losartan increases NO release in afferent arterioles during regression of L-NAME-induced renal damage.

    PubMed

    Helle, Frank; Iversen, Bjarne M; Chatziantoniou, Christos

    2010-05-01

    Inhibition of nitric oxide synthesis (NOS) induces hypertension and heavy proteinuria. Renal structure and function have shown striking improvement after interventions targeting ANG II or endothelin (ET) receptors in rats recovering after long-term NOS inhibition. To search for mechanisms underlying losartan-assisted regression of renal disease in rodents, we measured NO release and contractility to ET in afferent arterioles (AAs) from Sprague-Dawley rats recovering for 2 wk after 4 wk of N(G)-nitro-L-arginine methyl ester treatment. Losartan administration during the recovery period decreased blood pressure (113 ± 4 vs. 146 ± 5 mmHg, P < 0.01), reduced protein/creatinine ratio more (proteinuria decrease: Δ1,836 ± 214 vs. Δ1,024 ± 180 mg/mmol, P < 0.01), and normalized microvascular hypertrophy (AA media/lumen ratio: 1.74 ± 0.05 vs. 2.09 ± 0.08, P < 0.05) compared with no treatment. In diaminofluorescein-FM-loaded AAs from losartan-treated animals, NO release (% of baseline) was increased compared with untreated animals after stimulation with 10(-7) M ACh (118 ± 4 vs. 90 ± 7%, t = 560 s, P < 0.001) and 10(-9) M ET (123 ± 4 vs. 101 ± 5%, t = 560 s, P < 0.001). There was also a blunted contractile response to 10(-7) M ET in AAs from losartan-treated animals compared with untreated animals (Δ4.01 ± 2.9 vs. Δ14.6 ± 1.7 μm, P < 0.01), which disappeared after acute NOS inhibition (Δ10.7 ± 3.7 vs. Δ12.5 ± 2.9 μm, not significant). Contractile dose responses to ET (10(-9), 10(-8), 10(-7) M) were enhanced by NOS inhibition and blunted by exogenous NO (10(-2) mM S-nitroso-N-acetyl-penicillamine) in losartan-treated but not in untreated vessels. Reducing blood pressure similar to losartan with hydralazine did not improve AA hypertrophy, ET-induced contractility, ET-induced NO release, and NO sensitivity. In conclusion, blockade of the local action of ANG II improved endothelial function in AAs, a mechanism that is likely to contribute to the beneficial

  3. Subacute Zinc Administration and L-NAME Caused an Increase of NO, Zinc, Lipoperoxidation, and Caspase-3 during a Cerebral Hypoxia-Ischemia Process in the Rat

    PubMed Central

    Blanco-Alvarez, Victor Manuel; Lopez-Moreno, Patricia; Soto-Rodriguez, Guadalupe; Martinez-Fong, Daniel; Rubio, Hector; Gonzalez-Barrios, Juan Antonio; Piña-Leyva, Celia; Torres-Soto, Maricela; Gomez-Villalobos, María de Jesus; Hernandez-Baltazar, Daniel; Eguibar, José Ramon; Ugarte, Araceli; Cebada, Jorge

    2013-01-01

    Zinc or L-NAME administration has been shown to be protector agents, decreasing oxidative stress and cell death. However, the treatment with zinc and L-NAME by intraperitoneal injection has not been studied. The aim of our work was to study the effect of zinc and L-NAME administration on nitrosative stress and cell death. Male Wistar rats were treated with ZnCl2 (2.5 mg/kg each 24 h, for 4 days) and N-ω-nitro-L-arginine-methyl ester (L-NAME, 10 mg/kg) on the day 5 (1 hour before a common carotid-artery occlusion (CCAO)). The temporoparietal cortex and hippocampus were dissected, and zinc, nitrites, and lipoperoxidation were assayed at different times. Cell death was assayed by histopathology using hematoxylin-eosin staining and caspase-3 active by immunostaining. The subacute administration of zinc before CCAO decreases the levels of zinc, nitrites, lipoperoxidation, and cell death in the late phase of the ischemia. L-NAME administration in the rats treated with zinc showed an increase of zinc levels in the early phase and increase of zinc, nitrites, and lipoperoxidation levels, cell death by necrosis, and the apoptosis in the late phase. These results suggest that the use of these two therapeutic strategies increased the injury caused by the CCAO, unlike the alone administration of zinc. PMID:23997853

  4. Increasing dietary linoleic acid does not increase tissue arachidonic acid content in adults consuming Western-type diets: a systematic review

    PubMed Central

    2011-01-01

    Background Linoleic acid, with a DRI of 12-17 g/d, is the most highly consumed polyunsaturated fatty acid in the Western diet and is found in virtually all commonly consumed foods. The concern with dietary linoleic acid, being the metabolic precursor of arachidonic acid, is its consumption may enrich tissues with arachidonic acid and contribute to chronic and overproduction of bioactive eicosanoids. However, no systematic review of human trials regarding linoleic acid consumption and subsequent changes in tissue levels of arachidonic acid has been undertaken. Objective In this study, we reviewed the human literature that reported changes in dietary linoleic acid and its subsequent impact on changing tissue arachidonic acid in erythrocytes and plasma/serum phospholipids. Design We identified, reviewed, and evaluated all peer-reviewed published literature presenting data outlining changes in dietary linoleic acid in adult human clinical trials that reported changes in phospholipid fatty acid composition (specifically arachidonic acid) in plasma/serum and erythrocytes within the parameters of our inclusion/exclusion criteria. Results Decreasing dietary linoleic acid by up to 90% was not significantly correlated with changes in arachidonic acid levels in the phospholipid pool of plasma/serum (p = 0.39). Similarly, when dietary linoleic acid levels were increased up to six fold, no significant correlations with arachidonic acid levels were observed (p = 0.72). However, there was a positive relationship between dietary gamma-linolenic acid and dietary arachidonic acid on changes in arachidonic levels in plasma/serum phospholipids. Conclusions Our results do not support the concept that modifying current intakes of dietary linoleic acid has an effect on changing levels of arachidonic acid in plasma/serum or erythrocytes in adults consuming Western-type diets. PMID:21663641

  5. The increased level of COX-dependent arachidonic acid metabolism in blood platelets from secondary progressive multiple sclerosis patients.

    PubMed

    Morel, Agnieszka; Miller, Elzbieta; Bijak, Michal; Saluk, Joanna

    2016-09-01

    Platelet activation is increasingly postulated as a possible component of the pathogenesis of multiple sclerosis (MS), especially due to the increased risk of cardiovascular events in MS. Arachidonic acid cascade metabolized by cyclooxygenase (COX) is a key pathway of platelet activation. The aim of our study was to investigate the COX-dependent arachidonic acid metabolic pathway in blood platelets from secondary progressive multiple sclerosis (SP MS) patients. The blood samples were obtained from 50 patients (man n = 22; female n = 28), suffering from SP MS, diagnosed according to the revised McDonald criteria. Platelet aggregation was measured in platelet-rich plasma after arachidonic acid stimulation. The level of COX activity and thromboxane B2 concentration were determined by ELISA method. Lipid peroxidation was assessed by measuring the level of malondialdehyde. The results were compared with a control group of healthy volunteers. We found that blood platelets obtained from SP MS patients were more sensitive to arachidonic acid and their response measured as platelet aggregation was stronger (about 14 %) relative to control. We also observed a significantly increased activity of COX (about 40 %) and synthesis of thromboxane B2 (about 113 %). The generation of malondialdehyde as a marker of lipid peroxidation was about 10 % higher in SP MS than in control. Cyclooxygenase-dependent arachidonic acid metabolism is significantly increased in blood platelets of patients with SP MS. Future clinical studies are required to recommend the use of low-dose aspirin, and possibly other COX inhibitors in the prevention of cardiovascular risk in MS. PMID:27507559

  6. Lovastatin increases arachidonic acid levels and stimulates thromboxane synthesis in human liver and monocytic cell lines.

    PubMed Central

    Hrboticky, N; Tang, L; Zimmer, B; Lux, I; Weber, P C

    1994-01-01

    The effect of lovastatin (LOV), the inhibitor of 3-hydroxy-3-methyl-glutaryl coenzyme A reductase, on linoleic acid (LA, 18:2n-6) metabolism was examined in human monocytic Mono Mac 6 (MM6) and hepatoma Hep G2 cells. The desaturation of LA was examined after LOV (72 h, 10 microM) or dimethylsulfoxide (LOV carrier, < 0.1%) and [14C]LA (last 18 h, 0.3 microCi, 5 microM). In both cell lines, LOV reduced the percentage of 14C label associated with LA and increased the percentage of label in the 20:4n-6 and the 22:5n-6 fractions. In Hep G2 but not MM6 cells, this effect was fully reversible by means of coincubation with mevalonic acid (500 microM), but not with cholesterol or lipoproteins. In both cell lines, the LOV-mediated increase in LA desaturation resulted in dose-dependent reductions of LA and elevations of AA in cellular phospholipids. The lipids secreted by LOV-treated Hep G2 cells were also enriched in arachidonic acid (AA). In the MM6 cells, LOV increased release of thromboxane upon stimulation with the calcium ionophore A23187. In summary, our findings of higher LA desaturation and AA enrichment of lipids secreted by the Hep G2 cells suggest that LOV treatment may increase the delivery of AA from the liver to extrahepatic tissues. The changes in membrane fatty acid composition can influence a variety of cellular functions, such as eicosanoid synthesis in monocytic cells. The mechanism appears to be related to the reduced availability of intermediates of cholesterogenesis. PMID:8282787

  7. Linoleic acid supplementation results in increased arachidonic acid and eicosanoid production in CF airway cells and in cftr−/− transgenic mice

    PubMed Central

    Zaman, Munir M.; Martin, Camilia R.; Andersson, Charlotte; Bhutta, Abdul Q.; Cluette-Brown, Joanne E.; Laposata, Michael

    2010-01-01

    Cystic fibrosis (CF) patients display a fatty acid imbalance characterized by low linoleic acid levels and variable changes in arachidonic acid. This led to the recommendation that CF patients consume a high-fat diet containing >6% linoleic acid. We hypothesized that increased conversion of linoleic acid to arachidonic acid in CF leads to increased levels of arachidonate-derived proinflammatory metabolites and that this process is exacerbated by increasing linoleic acid levels in the diet. To test this hypothesis, we determined the effect of linoleic acid supplementation on downstream proinflammatory biomarkers in two CF models: 1) in vitro cell culture model using 16HBE14o− sense [wild-type (WT)] and antisense (CF) human airway epithelial cells; and 2) in an in vivo model using cftr−/− transgenic mice. Fatty acids were analyzed by gas chromatography-mass spectrometry (GC/MS), and IL-8 and eicosanoids were measured by ELISA. Neutrophils were quantified in bronchoalveolar lavage fluid from knockout mice following linoleic acid supplementation and exposure to aerosolized Pseudomonas LPS. Linoleic acid supplementation increased arachidonic acid levels in CF but not WT cells. IL-8, PGE2, and PGF2α secretion were increased in CF compared with WT cells, with a further increase following linoleic acid supplementation. cftr−/− Mice supplemented with 100 mg of linoleic acid had increased arachidonic acid levels in lung tissue associated with increased neutrophil infiltration into the airway compared with control mice. These findings support the hypothesis that increasing linoleic acid levels in the setting of loss of cystic fibrosis transmembrane conductance regulator (CFTR) function leads to increased arachidonic acid levels and proinflammatory mediators. PMID:20656894

  8. cAMP increases mitochondrial cholesterol transport through the induction of arachidonic acid release inside this organelle in Leydig cells.

    PubMed

    Castillo, Ana Fernanda; Cornejo Maciel, Fabiana; Castilla, Rocío; Duarte, Alejandra; Maloberti, Paula; Paz, Cristina; Podestá, Ernesto J

    2006-11-01

    We have investigated the direct effect of arachidonic acid on cholesterol transport in intact cells or isolated mitochondria from steroidogenic cells and the effect of cyclic-AMP on the specific release of this fatty acid inside the mitochondria. We show for the first time that cyclic-AMP can regulate the release of arachidonic acid in a specialized compartment of MA-10 Leydig cells, e.g. the mitochondria, and that the fatty acid induces cholesterol transport through a mechanism different from the classical pathway. Arachidonic acid and arachidonoyl-CoA can stimulate cholesterol transport in isolated mitochondria from nonstimulated cells. The effect of arachidonoyl-CoA is inhibited by the reduction in the expression or in the activity of a mitochondrial thioesterase that uses arachidonoyl-CoA as a substrate to release arachidonic acid. cAMP-induced arachidonic acid accumulation into the mitochondria is also reduced when the mitochondrial thioesterase activity or expression is blocked. This new feature in the regulation of cholesterol transport by arachidonic acid and the release of arachidonic acid in specialized compartment of the cells could offer novel means for understanding the regulation of steroid synthesis but also would be important in other situations such as neuropathological disorders or oncology disorders, where cholesterol transport plays an important role.

  9. Propolis reduces oxidative stress in l-NAME-induced hypertension rats.

    PubMed

    Selamoglu Talas, Zeliha

    2014-03-01

    The inhibition in the synthesis or bioavailability of nitric oxide (NO) has an important role in progress of hypertension. The blocking of nitric oxide synthase activity may cause vasoconstriction with the formation of reactive oxygen species (ROS). Propolis is a resinous substance collected by honey bees from various plants. Propolis has biological and pharmacological properties. The aim of this study was to examine the effect of propolis on catalase (CAT) activity, malondialdehyde (MDA) and NO levels in the testis tissues of hypertensive rats by Nω-nitro-l-arginine methyl ester (l-NAME). Rats have received nitric oxide synthase inhibitor (l-NAME, 40 mg kg(-1) , intraperitoneally) for 15 days to produce hypertension and propolis (200 mg kg(-1) , by gavage) during the last 5 days. MDA level in l-NAME-treated group significantly increased compared with control group (P < 0.01). MDA level of l-NAME + propolis-treated rats significantly reduced (P < 0.01) compared with l-NAME-treated group. CAT activity and NO level significantly reduced (P < 0.01) in l-NAME group compared with control group. There were no statistically significant increases in the CAT activity and NO level of the l-NAME + propolis group compared with the l-NAME-treated group (P > 0.01). These results suggest that propolis changes CAT activity, NO and MDA levels in testis of l-NAME-treated animals, and so it may modulate the antioxidant system.

  10. Effect of post-trial L-NAME administration on cocaine sensitization.

    PubMed

    Pudiak, Cindy M; Bozarth, Michael A

    2013-09-01

    This study determined if Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME) administered after the cocaine-conditioning trial attenuated the development of sensitization to cocaine's locomotor-stimulating effect and secondly, determined if L-NAME blocked conditioned-locomotor activity (LMA) elicited by a saline-challenge injection. Results revealed that cocaine-injected animals (10 mg/kg, i.p.) showed enhanced locomotor activity across the three conditioning trials (all p's < .05). Cocaine-injected animals administered L-NAME (30 mg/kg, i.p.) after each conditioning trial showed a slight increase in cocaine-stimulated LMA from the first to the second conditioning trial (all p's < .05) and no further increases in LMA thereafter. A saline-challenge injection administered 72 hr after the last conditioning trial revealed that cocaine-injected animals displayed as much locomotor stimulation to a saline injection as they did during their initial exposure to cocaine on the first conditioning trial - indicating the development of cocaine-conditioned LMA. The present findings show that L-NAME administered after the cocaine-conditioning trial attenuates the development of sensitization to cocaine's locomotor-stimulating effect. The failure of L-NAME to block cocaine-conditioned LMA suggests that the pharmacological and conditioning mechanisms of sensitization can be dissociated. It is unlikely that L-NAME's effect is due to a sedative action produced by residual L-NAME since animals administered L-NAME (30 mg/kg, i.p.) for 10 consecutive days exhibited a similar responsiveness to a cocaine challenge administered 3 and 10 days following the termination of L-NAME administration. These data support a role for nitric oxide's involvement in the neuroadaptive responses that result from continued stimulant administration and demonstrate the importance of conditioned drug effects.

  11. Intake of farmed Atlantic salmon fed soybean oil increases hepatic levels of arachidonic acid-derived oxylipins and ceramides in mice.

    PubMed

    Midtbø, Lisa Kolden; Borkowska, Alison G; Bernhard, Annette; Rønnevik, Alexander Krokedal; Lock, Erik-Jan; Fitzgerald, Michael L; Torstensen, Bente E; Liaset, Bjørn; Brattelid, Trond; Pedersen, Theresa L; Newman, John W; Kristiansen, Karsten; Madsen, Lise

    2015-06-01

    Introduction of vegetable ingredients in fish feed has affected the fatty acid composition in farmed Atlantic salmon (Salmo salar L). Here we investigated how changes in fish feed affected the metabolism of mice fed diets containing fillets from such farmed salmon. We demonstrate that replacement of fish oil with rapeseed oil or soybean oil in fish feed had distinct spillover effects in mice fed western diets containing the salmon. A reduced ratio of n-3/n-6 polyunsaturated fatty acids in the fish feed, reflected in the salmon, and hence also in the mice diets, led to a selectively increased abundance of arachidonic acid in the phospholipid pool in the livers of the mice. This was accompanied by increased levels of hepatic ceramides and arachidonic acid-derived pro-inflammatory mediators and a reduced abundance of oxylipins derived from eicosapentaenoic acid and docosahexaenoic acid. These changes were associated with increased whole body insulin resistance and hepatic steatosis. Our data suggest that an increased ratio between n-6 and n-3-derived oxylipins may underlie the observed marked metabolic differences between mice fed the different types of farmed salmon. These findings underpin the need for carefully considering the type of oil used for feed production in relation to salmon farming.

  12. Angiotensin II and prostaglandin interactions on systemic and renal effects of L-NAME in humans.

    PubMed

    Perinotto, P; Biggi, A; Carra, N; Orrico, A; Valmadre, G; Dall'Aglio, P; Novarini, A; Montanari, A

    2001-08-01

    For investigation of whether interactions between prostaglandins and angiotensin II modulate renal response to acute nitric oxide synthesis inhibition in humans, seven young volunteers who were kept on a 240-mM Na diet underwent four experiments with 90 min of infusion of 3.0 microg/kg.min(-1) NG-nitro-L-arginine methyl ester (L-NAME), each preceded by a 3-d treatment with placebo (PL), 50 mg of losartan (LOS), 75 to 125 mg of indomethacin (IND), or both drugs. Mean arterial pressure (MAP), GFR, effective renal plasma flow (ERPF), and Na excretion rate (UNaV) were measured at baseline and from 0 to 45 min and 45 to 90 min of L-NAME infusion. After PL, L-NAME reduced GFR by 5% at 45 min (P < 0.05) and by 9% at 90 min (P < 0.001), ERPF by 11 to 17% (P < 0.001), and UNaV by 28 to 45% (P < 0.001). MAP, unchanged at 45 min, rose by 5% (P < 0.001) at 90 min. LOS prevented pressor but not renal effects of L-NAME. With L-NAME+IND, MAP rose even at 45 min (+5%; P < 0.001 versus baseline) with a 10% rise at 90 min (P < 0.001). Changes in GFR (-13 to -20%), ERPF (-19 to -26%), and UNaV (-51 to -70%) were greater than those with L-NAME+PL or L-NAME+LOS (P < 0.05 to 0.001). With L-NAME+IND+LOS, MAP did not increase, and GFR, ERPF, and UNaV fell much less than with L-NAME+IND alone (P < 0.02 to 0.001) with no differences versus PL or LOS alone. Angiotensin II blockade does not affect renal changes caused by L-NAME but prevents their potentiation by prostaglandin inhibition. Thus, endogenous prostaglandins counteract renal actions of endogenous angiotensin II in Na-repleted humans even when nitric oxide synthesis is inhibited.

  13. Effect of Sildenafil on Pre-Eclampsia-Like Mouse Model Induced By L-Name.

    PubMed

    Motta, C; Grosso, C; Zanuzzi, C; Molinero, D; Picco, N; Bellingeri, R; Alustiza, F; Barbeito, C; Vivas, A; Romanini, M C

    2015-08-01

    N(omega)-nitro-L-arginine methyl ester (L-NAME) decreases the vasodilator effect of nitric oxide (NO) and induces pre-eclampsia in mouse. Sildenafil inhibits the degradation of nitric oxide and increases vasodilation. This study aimed to determine the effects of sildenafil citrate on angiogenesis and oxidative stress at the maternal foetal interface on pre-eclampsia-like mouse model induced by L-NAME. Twenty pregnant mice were divided into four groups: (i) vehicle control; (ii) L-NAME; (iii) sildenafil; (4) L-NAME+sildenafil. L-NAME was administered from day 7 of pregnancy and sildenafil from day 8 until day 16; animals were euthanized on day 17. Placental and foetal sizes and weights were measured; lipid peroxide levels and catalase activity in placental homogenates were determined, and placental vascular endothelia were identified by lectin-histochemistry using BSA-I lectin. Western blot analysis was used to determine VEGF expression in placental homogenates. No changes were seen in placental and foetal development in mice with normal pregnancies treated with sildenafil. Treatments with L-NAME reduced significantly the placental weight and average height and decreased the percentage of the endothelial surface. These alterations may be mediated by the reduction of NO levels in trophoblastic cells, due to the inhibitory effect of L-NAME on nitric oxide synthase (NOS) synthesis. This effect was offset by the treatment with sildenafil, with an increase in the percentage of the endothelial surface. In conclusion, our results indicate that treatment with sildenafil on pre-eclampsia mouse model can be used without adverse effects on the concept and its use in the treatment of pre-eclampsia is promising.

  14. Barnidipine ameliorates the vascular and renal injury in L-NAME-induced hypertensive rats.

    PubMed

    Alp Yildirim, F Ilkay; Eker Kizilay, Deniz; Ergin, Bülent; Balci Ekmekçi, Özlem; Topal, Gökçe; Kucur, Mine; Demirci Tansel, Cihan; Uydeş Doğan, B Sönmez

    2015-10-01

    The present study was aimed to investigate the influence of Barnidipine treatment on early stage hypertension by determining the function and morphology of the mesenteric and renal arteries as well as the kidney in N(ω)-Nitro-L-Arginine Methyl Ester (L-NAME)-induced hypertensive rats. Barnidipine (3 mg/kg/day p.o) was applied to rats after 2 weeks of L-NAME (60 mg/kg/day) administration, and continued for the next 3 weeks concomitantly with L-NAME. The systolic blood pressure (SBP) of rats was determined to decrease significantly in Barnidipine treated hypertensive group when compared to that of rats received L-NAME alone. Myograph studies demonstrated that the contractile reactivity to noradrenaline were significantly reduced in both of the resistance arteries while endothelium-dependent relaxations to acethylcholine were significantly diminished particularly in the mesenteric arteries of L-NAME-induced hypertensive rats. The impaired contractile and endothelial responses were completely restored by concomitant treatment of Barnidipine with L-NAME. Histopathological examinations verified structural alterations in the arteries as well as the kidney. Moreover, a decrease in endothelial nitric oxide synthase (eNOS) expression was presented both in the arteries and kidney of hypertensive rats which were increased following Barnidipine treatment. Elevated plasma levels of malondialdehyde (MDA) and myeloperoxidase (MPO) were also reduced in Barnidipine treated hypertensive rats. In conclusion, besides to its efficacy in reducing the elevated SBP, amelioration of vascular function, modulation of arterial and renal eNOS expressions as well as reduction of the plasma levels of oxidative and inflammatory biomarkers are possible supportive mechanisms mediating the favorable implications of Barnidipine in L-NAME-induced hypertension model. PMID:26187312

  15. The Effect of Magnesium on Visual Evoked Potentials in L-NAME-Induced Hypertensive Rats.

    PubMed

    Ozsoy, Ozlem; Aras, Sinem; Ulker Karadamar, Pinar; Nasircilar Ulker, Seher; Kocer, Gunnur; Senturk, Umit Kemal; Basrali, Filiz; Yargicoglu, Piraye; Ozyurt, Dilek; Agar, Aysel

    2016-08-01

    In the literature, although there are many studies regarding complications of hypertension, information concerning its influence on visual evoked potentials (VEPs) is limited. This study aims to clarify the possible therapeutic effects of the preferential magnesium (Mg) treatment on VEPs in an experimental hypertension model. Rats were divided into four groups as follows: control, Mg treated (Mg), N(omega)-nitro-L-arginine methyl ester (L-NAME) hypertension, and L-NAME hypertension + Mg treated (L-NAME + Mg). Hypertension was induced by L-NAME which was given to rats orally over 6 weeks (25 mg/kg/day in drinking water). A magnesium-enriched diet (0.8 g/kg) was given to treatment groups for 6 weeks. Systolic blood pressure (SBP) was determined by using the tail-cuff method. Flash VEPs were recorded. Our results revealed that the SBP was significantly increased in the L-NAME group compared to control. Magnesium treatment significantly attenuated SBP in the hypertensive rats compared to the L-NAME group. The mean latencies of P1, N1, P2, N2, and P3 components were significantly prolonged in hypertensive rats compared to control. Treatment with Mg provided a significant decrease in the latencies of P1, N1, P2, N2, and P3 potentials in the L-NAME + Mg group compared to the L-NAME group. Plasma Mg levels were increased in the L-NAME + Mg group compared to the L-NAME group. No change was detected in the Mg levels of the brains in all experimental groups. Magnesium treatment had no effect on the brain nitrate/nitrite and thiobarbituric acid-reactive substances (TBARS) levels in hypertensive rats compared to non-treated rats. There was a positive correlation between the brain TBARS levels and SBP of the rats. The present study suggests that Mg supplementation has the potential to prevent VEP changes in the L-NAME-induced hypertension model.

  16. Increased arachidonic acid-containing phosphatidylcholine is associated with reactive microglia and astrocytes in the spinal cord after peripheral nerve injury.

    PubMed

    Xu, Dongmin; Omura, Takao; Masaki, Noritaka; Arima, Hideyuki; Banno, Tomohiro; Okamoto, Ayako; Hanada, Mitsuru; Takei, Shiro; Matsushita, Shoko; Sugiyama, Eiji; Setou, Mitsutoshi; Matsuyama, Yukihiro

    2016-01-01

    Peripheral nerve injury (PNI) triggers cellular and molecular changes in the spinal cord. However, little is known about how the polyunsaturated fatty acid-containing phosphatidylcholines (PUFA-PCs) are regulated in the spinal cord after PNI and the association of PUFA-PCs with the non-neuronal cells within in the central nervous system (CNS). In this study, we found that arachidonic acid-containing phosphatidylcholine (AA-PC), [PC(16:0/20:4)+K](+), was significantly increased in the ipsilateral ventral and dorsal horns of the spinal cord after sciatic nerve transection, and the increased expression of [PC(16:0/20:4)+K](+) spatiotemporally resembled the increase of reactive microglia and the astrocytes. From the lipidomics point of view, we conclude that [PC(16:0/20:4)+K](+) could be the main phospholipid in the spinal cord influenced by PNI, and the regulation of specific phospholipid molecule in the CNS after PNI is associated with the reactive microglia and astrocytes. PMID:27210057

  17. Increased arachidonic acid-containing phosphatidylcholine is associated with reactive microglia and astrocytes in the spinal cord after peripheral nerve injury

    PubMed Central

    Xu, Dongmin; Omura, Takao; Masaki, Noritaka; Arima, Hideyuki; Banno, Tomohiro; Okamoto, Ayako; Hanada, Mitsuru; Takei, Shiro; Matsushita, Shoko; Sugiyama, Eiji; Setou, Mitsutoshi; Matsuyama, Yukihiro

    2016-01-01

    Peripheral nerve injury (PNI) triggers cellular and molecular changes in the spinal cord. However, little is known about how the polyunsaturated fatty acid-containing phosphatidylcholines (PUFA-PCs) are regulated in the spinal cord after PNI and the association of PUFA-PCs with the non-neuronal cells within in the central nervous system (CNS). In this study, we found that arachidonic acid-containing phosphatidylcholine (AA-PC), [PC(16:0/20:4)+K]+, was significantly increased in the ipsilateral ventral and dorsal horns of the spinal cord after sciatic nerve transection, and the increased expression of [PC(16:0/20:4)+K]+ spatiotemporally resembled the increase of reactive microglia and the astrocytes. From the lipidomics point of view, we conclude that [PC(16:0/20:4)+K]+ could be the main phospholipid in the spinal cord influenced by PNI, and the regulation of specific phospholipid molecule in the CNS after PNI is associated with the reactive microglia and astrocytes. PMID:27210057

  18. Arbutus unedo prevents cardiovascular and morphological alterations in L-NAME-induced hypertensive rats Part I: cardiovascular and renal hemodynamic effects of Arbutus unedo in L-NAME-induced hypertensive rats.

    PubMed

    Afkir, Saida; Nguelefack, Telesphore Benoit; Aziz, Mohamed; Zoheir, Johar; Cuisinaud, Guy; Bnouham, Mohamed; Mekhfi, Hassane; Legssyer, Abdelkhaleq; Lahlou, Saad; Ziyyat, Abderrahim

    2008-03-01

    Hypertension induced by nitric oxide synthase inhibition is associated with functional abnormalities of the heart and kidney. The aim of the present study was to investigate whether chronic treatment with Arbutus unedo leaf (AuL) or root (AuR) aqueous extracts can prevent these alterations. Six groups of rats were used: control group received tap water; N(G)-nitro-l-arginine methyl-ester (L-NAME) group treated with L-NAME at 40 mg/kg/day; AuL and AuR groups received simultaneously L-NAME (40 mg/kg/day) and Au leaves or roots extract at the same concentration 250 mg/kg/day; l-arginine and enalapril groups received simultaneously L-NAME (40 mg/kg/day) and l-arginine at 50mg/kg/day or enalapril at 15 mg/kg/day. Treatment of rats during 4 weeks with L-NAME caused an increase of the systolic blood pressure (SBP) accompanied by a ventricular hypertrophy, an impairment of endothelium-dependent vasorelaxation, an increase of the cardiac baroreflex sensitivity and a decrease of water, sodium and potassium excretion. The co-administration of AuL or AuR extracts with L-NAME reduces the development of increased SBP, ameliorates the vascular reactivity as well as the baroreflex sensitivity and normalizes the renal function. AuR reduces the ventricular hypertrophy but AuL do not. Enalapril associated with L-NAME reverses the majority of alterations induced by L-NAME while l-arginine only lightly ameliorates the vascular reactivity. These results show that chronic treatment with Arbutus extract regress the development of hypertension and ameliorate cardiovascular and renal functions in NO deficient hypertension. PMID:18191352

  19. Neonatal dietary supplementation of arachidonic acid increases prostaglandin levels in adipose tissue but does not promote fat mass development in guinea pigs.

    PubMed

    Aprikian, Olivier; Reynaud, Denis; Pace-Asciak, Cecil; Leone, Patricia; Blancher, Florence; Monnard, Irina; Darimont, Christian; Macé, Katherine

    2007-11-01

    The role of arachidonic acid (AA) on the development of adipose tissue is still controversial since its metabolites, i.e., prostaglandins, can either stimulate or inhibit preadipocyte differentiation in vitro. In the present study, we evaluated the effects of early postnatal supplementation of AA on body weight and adipose tissue development in guinea pigs. Male newborn guinea pigs were fed for 21 days (day 21) with diets (milk and pellet) supplemented (+AA) or not (-AA) with 1.2% (total fatty acids) AA. From day 21 to day 105 both groups were fed a chow diet. The 21-days-old +AA pups showed a twofold higher AA accretion in phospholipids associated with a two- to sixfold increase in several prostaglandins, such as 6-keto PGF(1alpha) (the stable hydrolysis product of PGI(2)), PGF(2alpha), PGE(2), and PGD(2) in adipose tissue, compared with the -AA group. No difference in fat pad and body weight, aP2, and leptin gene expression in adipose tissue, fasting plasma glucose, free-fatty acids, and triglyceride concentration was observed between groups at day 21 or day 105. These results show that dietary supplementation of AA during the suckling/weaning period increases prostaglandin levels in adipose tissue but does not influence early fat mass development in the guinea pig.

  20. The Effects of Dexamethasone and L-NAME on Acute Lung Injury in Rats with Lung Contusion.

    PubMed

    Kozan, Ahmet; Kilic, Nermin; Alacam, Hasan; Guzel, Ahmet; Guvenc, Tolga; Acikgoz, Mehmet

    2016-10-01

    The therapeutic efficiency of an anti-inflammatory agent, dexamethasone (DXM), and a nitric oxide synthase (NOS) inhibitor, Nitro-L-arginine methyl ester (L-NAME), in lung tissue injury after lung contusion was investigated. Serum levels of tumor necrosis factor-alpha (TNF-α), interleukin-10 (IL-10), YKL-40, an inflammatory peptide, inducible NOS (iNOS), and Clara cell protein 16 (CC-16) were evaluated. Immunohistochemical analyses were also performed, and the lung tissue was examined histopathologically. The study consisted of eight groups of Sprague-Dawley rats (n = 10 in each group), weighing 250-300 g: (1) control, (2) contusion, (3) control + DXM, (4) contusion + DXM, (5) control + L-NAME (6) contusion + L-NAME, (7) control + DXM + L-NAME, and (8) contusion + DXM + L-NAME. A previously developed lung contusion model was used, in addition to the control group. The rats were administered DXM and L-NAME intraperitoneally (i.p.) at doses of 15 and 60 mg/kg/day, respectively. DXM and L-NAME administration decreased the iNOS level in the contusion groups. DXM increased the levels of YKL-40 and IL-10 in both the control and contusion groups, with higher levels in the contusion groups. L-NAME increased the serum level of IL-10 in the lung contusion groups. DXM increased the synthesis of CC-16 in the control and contusion groups. The combined use of a high-dose steroid and NOS inhibitor resulted in the death of the rats. Steroids can increase the level of cytokines, such as YKL-40 and IL-10, and the synthesis of CC-16 and prevent pneumonia, ALI/ARDS, and sepsis in lung contusion.

  1. Mechanisms of the antihypertensive effects of Nigella sativa oil in L-NAME-induced hypertensive rats

    PubMed Central

    Jaarin, Kamsiah; Foong, Wai Dic; Yeoh, Min Hui; Kamarul, Zaman Yusoff Nik; Qodriyah, Haji Mohd Saad; Azman, Abdullah; Zuhair, Japar Sidik Fadhlullah; Juliana, Abdul Hamid; Kamisah, Yusof

    2015-01-01

    OBJECTIVES This study was conducted to determine whether the blood pressure-lowering effect of Nigella sativa might be mediated by its effects on nitric oxide, angiotensin-converting enzyme, heme oxygenase and oxidative stress markers. METHODS: Twenty-four adult male Sprague-Dawley rats were divided equally into 4 groups. One group served as the control (group 1), whereas the other three groups (groups 2-4) were administered L-NAME (25 mg/kg, intraperitoneally). Groups 3 and 4 were given oral nicardipine daily at a dose of 3 mg/kg and Nigella sativa oil at a dose of 2.5 mg/kg for 8 weeks, respectively, concomitantly with L-NAME administration. RESULTS Nigella sativa oil prevented the increase in systolic blood pressure in the L-NAME-treated rats. The blood pressure reduction was associated with a reduction in cardiac lipid peroxidation product, NADPH oxidase, angiotensin-converting enzyme activity and plasma nitric oxide, as well as with an increase in heme oxygenase-1 activity in the heart. The effects of Nigella sativa on blood pressure, lipid peroxidation product, nicotinamide adenine dinucleotide phosphate oxidase and angiotensin-converting enzyme were similar to those of nicardipine. In contrast, L-NAME had opposite effects on lipid peroxidation, angiotensin-converting enzyme and NO. CONCLUSION: The antihypertensive effect of Nigella sativa oil appears to be mediated by a reduction in cardiac oxidative stress and angiotensin-converting enzyme activity, an increase in cardiac heme oxygenase-1 activity and a prevention of plasma nitric oxide loss. Thus, Nigella sativa oil might be beneficial for controlling hypertension. PMID:26602523

  2. Carotid body remodelling in l-NAME-induced hypertension in the rat.

    PubMed

    Felix, A S; Rocha, V N; Nascimento, A L R; de Carvalho, J J

    2012-05-01

    The carotid body (CB) is a chemoreceptor organ located at the bifurcation of the common carotid artery. It is made up of the carotid glomus, a structure containing type 1 cells surrounded by type 2 cells. The aim of this study was to evaluate the morphological changes of the CB and carotid glomus in the rat model of l-NAME-induced hypertension. Male Wistar rats were divided in two groups: control untreated rats (C) and rats receiving l-NAME 40 mg/kg/day (LN) for 6 weeks. At the end of the experiment, the systolic blood pressure was 63% higher in the LN group compared with the C group. Morphometric analysis showed that the area of the CB was 29% greater in the LN group compared with the C group. The density of nuclei in the CB was similar between groups, but it was 31% less in the carotid glomus of the LN group. Cells in the CB of the LN group displayed cytoplasmic vacuolation and expressed several biogenic amines. There were more elastic fibres, proteoglycans and collagen fibres in the LN group compared with the C group. Immunohistochemistry showed increased expression of nuclear factor kB, substance P, vascular endothelial growth factor and neuronal nitric oxide synthase in the LN group, while expression of the protein gene product 9.5 was decreased. l-NAME alters cell morphology and the expression of extracellular matrix molecules in the CB and carotid glomus in rats with l-NAME-induced hypertension. PMID:21899859

  3. Synergistic anti-nociceptive effect of L-NG-nitro arginine methyl ester (L-NAME) and flurbiprofen in the mouse.

    PubMed Central

    Morgan, C. V.; Babbedge, R. C.; Gaffen, Z.; Wallace, P.; Hart, S. L.; Moore, P. K.

    1992-01-01

    1. L-NG-nitro arginine methyl ester (L-NAME) administered i.p. produces anti-nociception in the mouse assessed by the formalin-induced paw licking and acetic acid-induced abdominal constriction models. The non-steroidal anti-inflammatory drug (NSAID), flurbiprofen, was similarly anti-nociceptive in both models. 2. Combination of a sub-threshold dose of L-NAME (10 mg kg-1) with increasing doses of flurbiprofen (25- 75 mg kg-1) or a sub-threshold dose of flurbiprofen (50 mg kg-1) with increasing doses of L-NAME (10- 100 mg kg-1) resulted in potentiated anti-nociception in the formalin model. Combined therapy with sub-threshold doses of L-NAME (10 mg kg-1) and indomethacin (10 mg kg-1) also resulted in significant anti-nociception. In addition, combining sub-threshold doses of L-NAME (12.5 mg kg-1) and flurbiprofen (2 mg kg-1) significantly reduced acetic acid-induced abdominal constriction. 3. L-NAME (10 mg kg-1) administered i.p. caused a significant (approximately 35%) increase in MAP in the urethane-anaesthetized mouse. Flurbiprofen (50 mg kg-1) was inactive. Combination treatment with L-NAME (10 mg kg-1) and flurbiprofen (50 mg kg-1) failed to elevate MAP above that observed with L-NAME alone. Neither L-NAME (10 mg kg-1) nor flurbiprofen (50 mg kg-1) either alone or in combination significantly altered mouse locomotor activity. 4. These results suggest that L-NAME and flurbiprofen/indomethacin act synergistically in their anti-nociceptive action in the mouse. Combination therapy with L-NAME and flurbiprofen and a similar NSAID may provide an alternative to the clinical control of pain in man. PMID:1393274

  4. Renal effects of Mammea africana Sabine (Guttiferae) stem bark methanol/methylene chloride extract on L-NAME hypertensive rats

    PubMed Central

    Nguelefack-Mbuyo, Elvine Pami; Dimo, Théophile; Nguelefack, Télesphore Benoit; Dongmo, Alain Bertrand; Kamtchouing, Pierre; Kamanyi, Albert

    2010-01-01

    Objective: The present study aims at evaluating the effects of methanol/methylene chloride extract of the stem bark of Mammea africana on the renal function of L-NAME treated rats. Material and Methods: Normotensive male Wistar rats were divided into five groups respectively treated with distilled water, L-NAME (40 mg/kg/day), L-NAME + L-arginine (100 mg/kg/day), L-NAME + captopril (20 mg/kg/day) or L-NAME + M. africana extract (200 mg/kg/day) for 30 days. Systolic blood pressure was measured before and at the end of treatment. Body weight was measured at the end of each week. Urine was collected 6 and 24 h after the first administration and further on day 15 and 30 of treatment for creatinine, sodium and potassium quantification, while plasma was collected at the end of treatment for the creatinine assay. ANOVA two way followed by Bonferonni or one way followed by Tukey were used for statistical analysis. Results: M. africana successfully prevented the rise in blood pressure and the acute natriuresis and diuresis induced by L-NAME. When given chronically, the extract produced a sustained antinatriuretic effect, a non-significant increase in urine excretion and reduced the glomerular hyperfiltration induced by L-NAME. Conclusions: The above results suggest that the methanol/methylene chloride extract of the stem bark of M. africana may protect kidney against renal dysfunction and further demonstrate that its antihypertensive effect does not depend on a diuretic or natriuretic activity. PMID:20927244

  5. Intake of Blueberry Fermented by Lactobacillus plantarum Affects the Gut Microbiota of L-NAME Treated Rats

    PubMed Central

    Ahrén, Irini Lazou; Prykhodko, Olena; Olsson, Crister; Ahrné, Siv; Molin, Göran

    2013-01-01

    Prebiotics, probiotics, or synbiotics can be used as means to regulate the microbiota to exert preventative or beneficial effects to the host. However, not much is known about the effect of the gut microbiota on hypertension which is a major risk factor of cardiovascular disease and also a symptom of the metabolic syndrome. The NG-nitro-L-arginine methyl ester (L-NAME) induced hypertensive rats were used in order to test the effect of a synbiotic dietary supplement of Lactobacillus plantarum HEAL19 either together with fermented blueberry or with three phenolic compounds synthesized during fermentation. The experimental diets did not lower the blood pressure after 4 weeks. However, the fermented blueberries together with live L. plantarum showed protective effect on liver cells indicated by suppressed increase of serum alanine aminotransferase (ALAT) levels. The diversity of the caecal microbiota was neither affected by L-NAME nor the experimental diets. However, inhibition of the nitric oxide synthesis by L-NAME exerted a selection pressure that led to a shift in the bacterial composition. The mixture of fermented blueberries with the bacterial strain altered the caecal microbiota in different direction compared to L-NAME, while the three phenolic compounds together with the bacteria eliminated the selection pressure from the L-NAME. PMID:23690854

  6. Endothelin-A blockade attenuates systemic and renal hemodynamic effects of L-NAME in humans.

    PubMed

    Montanari, A; Biggi, A; Carra, N; Fasoli, E; Calzolari, M; Corsini, F; Perinotto, P; Novarini, A

    2000-01-01

    Eight Na-repleted volunteers underwent 3 separate 90-minute infusions of either N(G)-nitro-L-arginine methyl ester (L-NAME) 3.0 mg. kg(-1). min(-1) or endothelin-A receptor (ET-A) blocker BQ-123 (BQ) 0.125 nmol. kg(-1). min(-1) or both. Mean arterial pressure (MAP), glomerular filtration rate (GFR), renal blood flow (RBF), renal vascular resistances (RVR), and sodium excretion rate (UNaV) were measured at baseline (b) and from 0 to 45 minutes (period 1) and 45 to 90 minutes (period 2) of infusion. BQ alone had no effect. GFR declined by 4.9% (P<0.001 versus b) in period 1, to 9.9% (P<0. 001) in period 2 with L-NAME, and by 3.3% (P<0.01) to 6.6% (P<0.001) with L-NAME plus BQ (P=NS between L-NAME and L-NAME plus BQ). UNaV fell equally with L-NAME or L-NAME plus BQ. MAP rose significantly in period 2 with L-NAME (6.9%; P<0.001) but not with coinfused BQ (2. 1%; P=NA versus b, P=0.005 versus L-NAME alone). RBF declined by 12. 2% (P<0.001) to 18.3% (P<0.001) with L-NAME and by 4.6% (P<0.005) to 8.2% (P<0.001) with L-NAME plus BQ. These changes were smaller with L-NAME plus BQ (P<0.05 in period 1 and P<0.02 in period 2). Blunted changes were also seen for RVR (P<0.005 in period 1 and P<0.001 in period 2 between L-NAME alone and L-NAME plus BQ). These findings show that systemic and renal vasoconstriction due to L-NAME are attenuated by BQ, which suggests that an interaction between endogenous nitric oxide production and ET-A activity participates in the maintenance of baseline systemic and renal vascular tone in humans.

  7. Irradiation of human skin by short wavelength ultraviolet radiation (100--290 nm) (u.v.C): increased concentrations of arachidonic acid and prostaglandines E2 and F2alpha.

    PubMed

    Camp, R D; Greaves, M W; Hensby, C N; Plummer, N A; Warin, A P

    1978-08-01

    1. Human abdominal skin was irradiated with six times the minimal erythema dose of ultraviolet C (100--290 nm) radiation. Erythema appeared at 3 h, was of moderate degree by 6 h and was maximal at 12--24 h. It was reduced at 48 h and by 72 h had disappeared. 2. A suction bulla technique was used for the recovery of exudate from normal and inflamed skin at 6, 18, 24 and 48 h after irradiation. 3. Prostaglandin-like activity, estimated by bioassay, showed maximum increase at 18 h, when erythema was also maximum. PGF 2alpha, measured by both radioimmunoassay and by combined gas-liquid chromatography--gas spectrometry, followed a similar time course then fell to normal, or near normal, levels at 48 h. 4. Prostaglandin E2 and arachidonic acid concentrations, measured by gas chromatography--mass spectrometry, were maximally raised at 18--24 h. At 48 h, when some erythema was still present, though reduced, prostaglandin E2 concentrations were still raised above control values. 5. The results provide direct evidence in support of the view that the erythma following irradiation of human skin by u.v.C involves activation of arachidonic acid metabolism. However, the relationship between the erythema and increased prostaglandin activity is not fully understood.

  8. Pentadecapeptide BPC 157 Reduces Bleeding and Thrombocytopenia after Amputation in Rats Treated with Heparin, Warfarin, L-NAME and L-Arginine

    PubMed Central

    Stupnisek, Mirjana; Kokot, Antonio; Drmic, Domagoj; Hrelec Patrlj, Masa; Zenko Sever, Anita; Kolenc, Danijela; Radic, Bozo; Suran, Jelena; Bojic, Davor; Vcev, Aleksandar; Seiwerth, Sven; Sikiric, Predrag

    2015-01-01

    Background BPC 157 is a stable gastric pentadecapeptide recently implicated with a role in hemostasis. While NO is largely implicated in hemostatic mechanisms, in tail-amputation-models under heparin- and warfarin-administration, both the NO-synthase (NOS)-blocker, L-NAME (prothrombotic) and the NOS-substrate L-arginine (antithrombotic), were little investigated. Objective. To investigate the effect of L-NAME and L-arginine on hemostatic parameters, and to reveal the effects of BPC 157 on the L-NAME- and L-arginine-induced hemostatic actions under different pathological condition: tail amputation without or with anticoagulants, heparin or warfarin. Methods Tail amputation, and/or i.v.-heparin (10 mg/kg), i.g.-warfarin (1.5 mg/kg/day for 3 days) were used in rats. Treatment includes BPC 157, L-NAME, L-arginine, per se and their combination. Results After (tail) amputation, with or without i.v.-heparin or i.g.-warfarin, BPC 157 (10 μg/kg, 10 ng/kg, i.p., i.v. (heparin), 10 μg/kg i.g. (warfarin)) always reduced bleeding time and/or haemorrhage and counteracted thrombocytopenia. As for L-NAME and/or L-arginine, we noted: L-arginine (100 mg/kg i.p.)–rats: more bleeding, less/no thrombocytopenia; L-NAME (5 mg/kg i.p.)-rats: less bleeding (amputation only), but present thrombocytopenia; L-NAME+L-arginine-rats also exhibited thrombocytopenia: L-NAME counteracted L-arginine-increased bleeding, L-arginine did not counteract L-NAME-thrombocytopenia. All animals receiving BPC 157 in addition (BPC 157μg+L-NAME; BPC 157μg+L-arginine, BPC 157μg+L-NAME+L-arginine), exhibited decreased haemorrhage and markedly counteracted thrombocytopenia. Conclusions L-NAME (thrombocytopenia), L-arginine (increased haemorrhage) counteraction and BPC 157 (decreased haemorrhage, counteracted thrombocytopenia) with rescue against two different anticoagulants, implicate a BPC 157 modulatory and balancing role with rescued NO-hemostatic mechanisms. PMID:25897838

  9. Impact of L-NAME on the cardiopulmonary reflex in cardiac hypertrophy.

    PubMed

    Buckley, Maria M; Johns, Edward J

    2011-11-01

    There is evidence that in cardiac failure, there is defective baroreceptor reflex control of sympathetic nerve activity. Often, cardiac failure is preceded by a state of cardiac hypertrophy in which there may be enhanced performance of the heart. This study investigated whether in two different models of cardiac hypertrophy, there was an increased contribution of nitric oxide (NO) to the low-pressure baroreceptor regulation of renal sympathetic nerve activity (RSNA) and nerve-dependent excretory function. Administration of a volume load, 0.25* body wt/min saline for 30 min, in normal rats decreased RSNA by 40* and increased urine flow by some 9-fold. Following nitro-L-arginine methyl ester (L-NAME) administration, 10 μg·kg(-1)·min(-1) for 60 min, which had no effect on blood pressure, heart rate, or RSNA, the volume load-induced renal sympathoinhibitory and excretory responses were markedly enhanced. In cardiac hypertrophy states induced by 2 wk of isoprenaline/caffeine or 1 wk thyroxine administration, the volume challenge failed to suppress RSNA, and there were blunted increases in urine flow in the innervated kidneys, but following L-NAME infusion, the volume load decreased RSNA by 30-40* and increased urine flow by some 20-fold in the innervated kidneys, roughly to the same extent as observed in normal rats. These findings suggest that the blunted renal sympathoinhibition and nerve-dependent diuresis to the volume load in cardiac hypertrophy are related to a heightened production or activity of NO within either the afferent or central arms of the reflex. PMID:21865544

  10. Inhibition of arachidonate release from rat peritoneal macrophage by biflavonoids.

    PubMed

    Lee, S J; Son, K H; Chang, H W; Kang, S S; Kim, H P

    1997-12-01

    Biflavonoid is one of unique classes of naturally-occurring bioflavonoid. Previously, certain biflavonoids were found to possess the inhibitory effects on phospholipase A(2) activity and lymphocytes proliferation(1) suggesting their anti-inflammatory/immunoregulatory potential. In this study, effects of several biflavonoids on arachidonic acid release from rat peritoneal macrophages were investigated, because arachidonic acid released from the activated macrophages is one of the indices of inflammatory conditions. When resident peritoneal macrophages labeled with [(3)H]arachidonic acid were activated by phorbol 12-myristate 13-acetate (PMA) or calcium ionophore, A23187, radioactivity released in the medium was increased approximately 4.1 approximately 7.3 fold after 120 min incubation compared to the spontaneous release in the control incubation. In this condition, biflavonoids (10 uM) such as ochnaflavone, ginkgetin and isoginkgetin, showed inhibition of arachidonate release from macrophages activated by PMA (32.5 approximately 40.0% inhibition) or A23187 (21.7 approximately 41.7% inhibition). Amentoflavone showed protection only against PMA-induced arachidonate release, while apigenin, a monomer of these biflavonoids, did not show the significant inhibition up to 10 uM. Staurosporin (1 uM), a protein kinase C inhibitor, showed an inhibitory effect only against PMA-induced arachidonate release (96.8% inhibition). Inhibition of arachidonate release from the activated macrophages may contribute to an anti-inflammatory potential of biflavonoidsin vivo.

  11. Asiatic acid alleviates cardiovascular remodelling in rats with L-NAME-induced hypertension.

    PubMed

    Bunbupha, Sarawoot; Prachaney, Parichat; Kukongviriyapan, Upa; Kukongviriyapan, Veerapol; Welbat, Jariya Umka; Pakdeechote, Poungrat

    2015-11-01

    A previous study demonstrated the antihypertensive effect of asiatic acid. The current study investigates the effect of asiatic acid on cardiovascular remodelling and possible mechanisms involved in Nω -nitro-L-arginine methyl ester hydrochloride (L-NAME)-induced hypertensive rats. Male Sprague-Dawley rats were treated with L-NAME (40 mg/kg per day) for 3 weeks in order to induce hypertension. Hypertensive rats were administered asiatic acid (20 mg/kg per day) or vehicle for a further 2 weeks. It was found that hypertensive rats showed high systolic blood pressure, left ventricular (LV) hypertrophy, increases in LV fibrosis, aortic wall thickness and aortic collagen deposition (P < 0.05). Moreover, decreased plasma nitrate and nitrite (NOx) and increased plasma tumor necrosis factor alpha (TNF-α) were observed in hypertensive rats (P < 0.05). This was consistent with downregulation of endothelial nitric oxide synthase (eNOS) expression and upregulation of inducible nitric oxide synthase (iNOS) expression in heart and aortic tissues (P < 0.05). Levels of malondialdehyde (MDA) in plasma, aortic and heart tissues were significantly increased in hypertensive rats (P < 0.05). Asiatic acid markedly reduced blood pressure, alleviated cardiovascular remodelling, and restored plasma NOx and TNF-α as well as eNOS/iNOS expression in heart and aortic tissues (P < 0.05). Additionally, there was a significant reduction of MDA levels in the tissues of treated hypertensive rats. In conclusion, this study demonstrates the therapeutic effects of asiatic acid on blood pressure and cardiovascular remodelling, which is possibly related to the restoration of eNOS/iNOS expression, and the resulting anti-inflammatory and antioxidant activities. PMID:26234646

  12. The effects of sildenafil after chronic L-NAME administration in male rat sexual behavior.

    PubMed

    Ferraz, Marcia M D; Quintella, Suelen L; Parcial, André L N; Ferraz, Marcos R

    2016-01-01

    Ferraz MMD, Quintella SL, Parcial ALN, Ferraz MR. The effects of sildenafil citrate and L-NAME on male rat sexual behaviour. PHARMACOL BIOCHEM BEHAV. Erectile dysfunction (ED) affects up to 50% of men between 40 and 70years of age. Significant advances in the pharmacological treatment of ED occurred in recent years, most notably the introduction of the first oral selective phosphodiesterase type-5 inhibitor, sildenafil. This study investigated the effectiveness of chronic oral treatment with L-NAME in rats as an experimental model of erectile dysfunction to evaluate new pharmacological agents that affect the sexual response. The effects of chronic oral L-NAME treatment, separately or in combination with sildenafil, on the sexual behaviour of male rats were evaluated. Filtered water was used as a control. Acute administration of L-NAME did not alter the sexual response compared with control, but sildenafil administration facilitated sexual behaviour after acute and chronic administration. Chronic L-NAME treatment inhibited motivational and consummatory measures of male rat sexual behaviour. Sildenafil prevented the inhibitory effects of L-NAME. The present results confirm that chronic oral treatment with a nitric oxide synthase inhibitor may be a relevant peripheral ED model to evaluate the effects of drugs on erectile function of male rats. PMID:27132237

  13. Renoprotective effect of sitagliptin against hypertensive nephropathy induced by chronic administration of L-NAME in rats: role of GLP-1 and GLP-1 receptor.

    PubMed

    Abd El Motteleb, Dalia M; Elshazly, Shimaa M

    2013-11-15

    The present study was undertaken to assess the possible protective effects of sitagliptin, a dipeptidyl peptidase 4-inhibitor (DPP4), against Nω-nitro-L-arginine methyl ester (L-NAME) induced hypertensive nephropathy in rats. Hypertension was induced in adult rats by administration of L-NAME for 6 weeks. Rats were treated with sitagliptin (10mg/kg/day or 30 mg/kg/day) for six weeks. Chronic L-NAME administration resulted in depletion of serum nitric oxide (NO) associated with elevation in the mean arterial pressure. When compared with the control group; serum urea, serum creatinine, albuminuria, urinary N-acetyl-ß-d-glucosaminidase (NAG) level and renal tissue malondialdhyde (MDA) content were significantly elevated, while creatinine clearance, serum level of glucagon like peptide-1 (GLP-1) as well as renal tissue superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were signifcantly decreased in L-NAME treated group. Renal expression of mRNA for eNOS and GLP-1 receptors were reduced in the L-NAME treated group as compared with the control group. Treatment with sitagliptin (10mg/kg or 30 mg/kg) successfully ameliorated the deleterious effects of L-NAME on the all tested parameters. Our study indicates a novel protective effect of sitagliptin against L-NAME induced hypertensive nephropathy. An effect which is mediated through, increasing serum level of GLP-1, upregulation of GLP-1 receptors, which in turn, lead to induction of expression eNOS, increased serum NO level, tandem with decreased lipid perodixation and restore the antioxidant defense mechanisms. It is worth mentioning that the effects produced by sitaglipin (30 mg/kg) were superior to the effects obtained by the lower dose.

  14. Effect of aliskiren, telmisartan and torsemide on cardiac dysfunction in l-nitro arginine methyl ester (l-NAME) induced hypertension in rats

    PubMed Central

    Sadek, Sawsan A.; Rashed, Laila A.; Bassam, Amira M.; Said, Eman S.

    2014-01-01

    Comparative study of cardio protective effect of aliskiren, telmisartan, and torsemide was carried out on l-nitro arginine methyl ester (l-NAME) induced hypertension in rats. The three drugs were given daily for 8 weeks simultaneously with l-NAME, with a control group for each drug and l-NAME. The degree of protection was assessed by measurement of systolic blood pressure and heart rate of animals every two weeks. At the end of the experimental period blood sampling was carried out for estimation of the level of NO2−/NO3−. After which animals were sacrificed for heart dissection to detect collagen types I and III gene expression. Histopathological study was done to evaluate the extension of collagen deposits. The study revealed that the three drugs decreased blood pressure significantly compared to l-NAME. There was no significant difference between aliskiren and telmisartan in all measurements, but there was significant decrease in measurements of both aliskiren and telmisartan treated groups compared to torsemide starting from 4th week. There were insignificant changes in pulse rate values between the three l-NAME treated groups through the experiment. The three drugs significantly increased NO compared to l-NAME. Collagen I and III gene expression was significantly decreased by the three drugs but the highest percentage of inhibition was with telmisartan compared to l-NAME. Comparing the percentage inhibition of cardiac fibrosis, there was insignificant difference between telmisartan and torsemide treated groups while both were superior to aliskiren. In conclusion, further experimental studies are required to elucidate the potential cardioprotective mechanisms of aliskiren, telmisartan and torsemide, and assess their efficacy in treatment of heart failure. PMID:26644935

  15. Detrimental effects of N(omega) nitro-L-arginine methyl ester (L-NAME)in experimental Escherichia coli sepsis in the newborn piglet.

    PubMed

    Kim, Sung Shin; Hwang, Jong Hee; Choi, Chang Won; Shim, Jae Won; Chang, Yun Sil; Park, Won Soon; Oh, Chang Kyu

    2003-10-01

    The role of nitric oxide during neonatal sepsis is complex. We tested the hypothesis that nonselective inhibition of nitric oxide synthase with N(omega) -nitro-L-arginine methyl ester (L-NAME) is detrimental during the early phase of experimental sepsis in the newborn piglet. Newborn piglets were divided into four groups: 6 in the control group, 6 in the L-NAME control group, 12 in the sepsis group (SG), and 11 in the sepsis with L-NAME group (NS). Sepsis was induced by intravenous injection of 10(8) colony forming units of Escherichia coli. L-NAME 10 mg/kg was given intravenously 60 min before the induction of sepsis. The survival rate of piglets after 4 hr was 27% in NS, while it was 100% in other groups. Systemic hypotension, observed in both SG and NS, were more profound in NS. Leukopenia was observed in both SG and NS. Thrombocytopenia, prolongation of prothrombin time and activated partial thromboplastin time, and increase in thrombin-antithrombin complexes were observed only in NS. Decreased PaO2 /FiO2 ratio, arterial pH and base excess, and increased blood lactate levels observed in both SG and NS, but were more profound in NS. These findings suggest that nonselective inhibition of nitric oxide synthase with L-NAME is detrimental during the early phase of experimental neonatal sepsis.

  16. Proliferation-dependent changes in release of arachidonic acid from endothelial cells.

    PubMed Central

    Whatley, R E; Satoh, K; Zimmerman, G A; McIntyre, T M; Prescott, S M

    1994-01-01

    Stimulation of endothelial cells resulted in release of arachidonic acid from phospholipids. The magnitude of this response decreased as the cells became confluent and the change coincided with a decrease in the percentage of cells in growth phases (G2+M); this was not a consequence of time in culture or a factor in the growth medium. Preconfluent cells released approximately 30% of arachidonic acid; confluent cells released only 6%. The decreasing release of arachidonic acid was demonstrated using metabolic labeling, mass measurements of arachidonic acid, and measurement of PGI2. The decrease was not due to a changing pool of arachidonic acid, and mass measurements showed no depletion of arachidonic acid. Release from each phospholipid and from each phospholipid class decreased with confluence. Conversion of confluent cells to the proliferative phenotype by mechanical wounding of the monolayer caused increased release of arachidonic acid. Potential mechanisms for these changes were investigated using assays of phospholipase activity. Phospholipase A2 activity changed in concert with the alteration in release, a consequence of changes in phosphorylation of the enzyme. The increased release of arachidonic acid from preconfluent, actively dividing cells may have important physiologic implications and may help elucidate mechanisms regulating release of arachidonic acid. Images PMID:7962534

  17. Effect of L-NAME-induced hypertension on melatonin receptors and melatonin levels in the pineal gland and the peripheral organs of rats.

    PubMed

    Benova, Miroslava; Herichova, Iveta; Stebelova, Katarina; Paulis, Ludovit; Krajcirovicova, Kristina; Simko, Fedor; Zeman, Michal

    2009-04-01

    Melatonin plays a role in blood pressure (BP) control. The aim of this study was to determine whether melatonin concentrations and melatonin receptor levels are altered in L-NAME-treated, NO-deficient hypertensive rats. Two groups of male adult Wistar rats were investigated: rats (n=36) treated with NO-synthase inhibitor L-NAME (40 mg kg(-1)) and age-matched controls (n=36). BP was measured weekly by tail-cuff plethysmography. After 4 weeks, L-NAME administration increased BP (178+/-1 vs. control 118+/-1 mm Hg). At the end of treatment, rats were killed in regular 4 h intervals over a 24-h period. Melatonin concentrations in the plasma, pineal gland, heart and kidney and melatonin receptor (MT(1)) density in the aorta were determined. A significant daily rhythm of melatonin concentrations was found in the blood, pineal gland, kidney and heart of both control and hypertensive rats. Peak nighttime pineal melatonin concentrations were higher in L-NAME-treated rats than in controls (3.38+/-0.48 vs. 1.75+/-0.33 ng per pineal gland). No differences between both groups were found in melatonin concentrations in blood, kidney and heart or in the MT(1) receptor density in the aorta. Our results suggest that L-NAME treatment enhances melatonin production in the pineal gland, potentially by decreasing an inhibitory effect of NO on melatonin production in the pineal gland. However, the enhanced pineal melatonin formation was insufficient to increase melatonin concentrations in circulation, heart and kidney of L-NAME-treated rats, indicating an increased use of melatonin in hypertensive animals.

  18. Effects of magnesium supplementation on electrophysiological remodeling of cardiac myocytes in L-NAME induced hypertensive rats.

    PubMed

    Ozturk, Nihal; Olgar, Yusuf; Aslan, Mutay; Ozdemir, Semir

    2016-08-01

    Hypertension is one of the major risk factors of cardiac hypertrophy and magnesium deficiency is suggested to be a contributing factor in the progression of this complication. In this study, we aimed to investigate the relationship between intracellular free Mg(2+) levels and electrophysiological changes developed in the myocardium of L-NAME induced hypertensive rats. Hypertension was induced by administration of 40 mg/kg of L-NAME for 6 weeks, while magnesium treated rats fed with a diet supplemented with 1 g/kg of MgO for the same period. L-NAME administration for 6 weeks elicited a significant increase in blood pressure which was corrected with MgO treatment; thereby cardiac hypertrophy developing secondary to hypertension was prevented. Cytosolic free magnesium levels of ventricular myocytes were significantly decreased with hypertension and magnesium administration restored these changes. Hypertension significantly decreased the fractional shortening with slowing of shortening kinetics in left ventricular myocytes whereas magnesium treatment was capable of restoring hypertension-induced contractile dysfunction. Long-term magnesium treatment significantly restored the hypertension-induced prolongation in action potentials of ventricular myocytes and suppressed Ito and Iss currents. In contrast, hypertension dependent decrement in intracellular Mg(2+) level did not cause a significant change in L-type Ca(2+) currents, SR Ca(2+) content and NCX activity. Nevertheless, hypertension mediated increase in superoxide anion, hydrogen peroxide and protein oxidation mitigated with magnesium treatment. In conclusion, magnesium administration improves mechanical abnormalities observed in hypertensive rat ventricular myocytes due to reduced oxidative stress. It is likely that, changes in intracellular magnesium balance may contribute to the pathophysiology of chronic heart diseases.

  19. Effects of magnesium supplementation on electrophysiological remodeling of cardiac myocytes in L-NAME induced hypertensive rats.

    PubMed

    Ozturk, Nihal; Olgar, Yusuf; Aslan, Mutay; Ozdemir, Semir

    2016-08-01

    Hypertension is one of the major risk factors of cardiac hypertrophy and magnesium deficiency is suggested to be a contributing factor in the progression of this complication. In this study, we aimed to investigate the relationship between intracellular free Mg(2+) levels and electrophysiological changes developed in the myocardium of L-NAME induced hypertensive rats. Hypertension was induced by administration of 40 mg/kg of L-NAME for 6 weeks, while magnesium treated rats fed with a diet supplemented with 1 g/kg of MgO for the same period. L-NAME administration for 6 weeks elicited a significant increase in blood pressure which was corrected with MgO treatment; thereby cardiac hypertrophy developing secondary to hypertension was prevented. Cytosolic free magnesium levels of ventricular myocytes were significantly decreased with hypertension and magnesium administration restored these changes. Hypertension significantly decreased the fractional shortening with slowing of shortening kinetics in left ventricular myocytes whereas magnesium treatment was capable of restoring hypertension-induced contractile dysfunction. Long-term magnesium treatment significantly restored the hypertension-induced prolongation in action potentials of ventricular myocytes and suppressed Ito and Iss currents. In contrast, hypertension dependent decrement in intracellular Mg(2+) level did not cause a significant change in L-type Ca(2+) currents, SR Ca(2+) content and NCX activity. Nevertheless, hypertension mediated increase in superoxide anion, hydrogen peroxide and protein oxidation mitigated with magnesium treatment. In conclusion, magnesium administration improves mechanical abnormalities observed in hypertensive rat ventricular myocytes due to reduced oxidative stress. It is likely that, changes in intracellular magnesium balance may contribute to the pathophysiology of chronic heart diseases. PMID:27193439

  20. Angiotensin II blockade does not prevent renal effects of L-NAME in sodium-repleted humans.

    PubMed

    Montanari, A; Tateo, E; Fasoli, E; Giberti, D; Perinotto, P; Novarini, A; Dall'Aglio, P

    1997-09-01

    In seven healthy, young subjects on a 240 mmol sodium diet, mean arterial pressure (MAP), renal hemodynamics, and renal handling of Na and exogenous Li were measured at baseline and during short-term nitric oxide (NO) blockade with a 90-minute infusion of 3.0 microg x kg(-1) x min(-1) of N(G)-L-arginine methyl ester (L-NAME). The infusion was performed twice: after a 3-day pretreatment with either placebo or 50 mg losartan to block Ang II receptors. With placebo, L-NAME produced no change in MAP from 0 to 45 minutes (period 1) and only a 5% increase at 45 to 90 minutes (period 2) of infusion. Effective renal plasma flow (ERPF, PAH clearance) and glomerular filtration rate (GFR, inulin clearance) declined by 11.7% and 8.0%, respectively in period 1 and by 14.6% and 11.6%, respectively, in period 2. Calculated renal vascular resistance (RVR) increased by 13.0% to 20.6%. Fractional excretion of Na (FE(Na)) and Li (FE(Li)) fell by 30.0% and 21.0%, respectively, in period 1 and by 44.2% and 31.1% in period 2. All these variations were significant versus baseline. With losartan, the rise in MAP at 45 to 90 minutes was completely abolished, whereas all changes in ERPF, GFR, RVR, FE(Na), and FE(Li) in response to L-NAME were the same as those observed with placebo. The present data show that NO blockade with low-dose systemic infusion of L-NAME produces renal vasoconstriction, reduced GFR, and increased tubular Na reabsorption independent of changes in MAP. Reduced FE(Li) indicates an effect of NO on the proximal tubule. Since these changes are not prevented by losartan, we conclude that in Na-repleted humans, renal vasoconstriction and Na-retaining effects of inhibition of basal NO production are not due to the unopposed action of endogenous Ang II.

  1. Arachidonic acid enhances reproduction in Daphnia magna and mitigates changes in sex ratios induced by pyriproxyfen.

    PubMed

    Ginjupalli, Gautam K; Gerard, Patrick D; Baldwin, William S

    2015-03-01

    Arachidonic acid is 1 of only 2 unsaturated fatty acids retained in the ovaries of crustaceans and an inhibitor of HR97g, a nuclear receptor expressed in adult ovaries. The authors hypothesized that, as a key fatty acid, arachidonic acid may be associated with reproduction and potentially environmental sex determination in Daphnia. Reproduction assays with arachidonic acid indicate that it alters female:male sex ratios by increasing female production. This reproductive effect only occurred during a restricted Pseudokirchneriella subcapitata diet. Next, the authors tested whether enriching a poorer algal diet (Chlorella vulgaris) with arachidonic acid enhances overall reproduction and sex ratios. Arachidonic acid enrichment of a C. vulgaris diet also enhances fecundity at 1.0 µM and 4.0 µM by 30% to 40% in the presence and absence of pyriproxyfen. This indicates that arachidonic acid is crucial in reproduction regardless of environmental sex determination. Furthermore, the data indicate that P. subcapitata may provide a threshold concentration of arachidonic acid needed for reproduction. Diet-switch experiments from P. subcapitata to C. vulgaris mitigate some, but not all, of arachidonic acid's effects when compared with a C. vulgaris-only diet, suggesting that some arachidonic acid provided by P. subcapitata is retained. In summary, arachidonic acid supplementation increases reproduction and represses pyriproxyfen-induced environmental sex determination in D. magna in restricted diets. A diet rich in arachidonic acid may provide protection from some reproductive toxicants such as the juvenile hormone agonist pyriproxyfen. Environ Toxicol Chem 2015;34:527-535. © 2014 SETAC.

  2. Purinergic contraction of the rat vas deferens in L-NAME-induced hypertension: effect of sildenafil

    PubMed Central

    Gur, Serap; Sikka, Suresh C.; Knight, Gillian E.; Burnstock, Geoffrey; Hellstrom, Wayne J.G.

    2010-01-01

    Hypertension (HTN) is a risk factor for erectile dysfunction, but its effect on vas deferens (VD) contractility and the ejaculatory response has not been delineated. NG-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, was used for induction of nitric oxide (NO)-deficient HTN. Our aim was to evaluate the effects of L-NAME-induced HTN on rat VD contractility and to determine whether sildenafil affects VD contractility. A total of 36 male rats were divided into (1) control, (2) L-NAME–HTN, (3) sildenafil treated L-NAME–HTN groups. Group 2 was treated with L-NAME (40 mg kg-1 per day) in drinking water for 4 weeks. Group 3 received sildenafil (1.5 mg kg−1 per day, by oral gavage) concomitantly with L-NAME. The prostatic portion of the VD was subjected to electrical field stimulation (EFS, 1–20 Hz), and the P2X1 agonist α,β-methylene ATP (α,β-meATP, 100 μmol L−1–1 μmol L−1) and the α1-adrenoceptor agonist phenylephrine (Phe, 100 μmol L−1–1 mmol L−1) were used to construct concentration-response curves. These experiments were repeated in the presence of P2X receptor antagonist, pyridoxalphosphate-6-azophenyl-2′,4′-disulfonic acid (PPADS, 30 μmol L−1). VD contractions in response to EFS, α,β-meATP and Phe were significantly enhanced by L-NAME. Sildenafil treatment in the L-NAME group improved the contractile response of VD to EFS (20 Hz). In the presence of PPADS, the enhanced contractile response of VD to EFS and α,β-meATP in hypertensive rats was reversed. In the rat model of chronic NO depletion, the purinergic and adrenergic components and EFS affect VD contractility. The VD contractile response may be mediated more by the purinergic system than the adrenergic system, and sildenafil may alter the ejaculatory response in men with PE. PMID:20305675

  3. Arachidonic acid enhances turnover of the dermal skeleton: studies on zebrafish scales.

    PubMed

    de Vrieze, Erik; Moren, Mari; Metz, Juriaan R; Flik, Gert; Lie, Kai Kristoffer

    2014-01-01

    In fish nutrition, the ratio between omega-3 and omega-6 poly-unsaturated fatty acids influences skeletal development. Supplementation of fish oils with vegetable oils increases the content of omega-6 fatty acids, such as arachidonic acid in the diet. Arachidonic acid is metabolized by cyclooxygenases to prostaglandin E2, an eicosanoid with effects on bone formation and remodeling. To elucidate effects of poly-unsaturated fatty acids on developing and existing skeletal tissues, zebrafish (Danio rerio) were fed (micro-) diets low and high in arachidonic acid content. Elasmoid scales, dermal skeletal plates, are ideal to study skeletal metabolism in zebrafish and were exploited in the present study. The fatty acid profile resulting from a high arachidonic acid diet induced mild but significant increase in matrix resorption in ontogenetic scales of adult zebrafish. Arachidonic acid affected scale regeneration (following removal of ontogenetic scales): mineral deposition was altered and both gene expression and enzymatic matrix metalloproteinase activity changed towards enhanced osteoclastic activity. Arachidonic acid also clearly stimulates matrix metalloproteinase activity in vitro, which implies that resorptive effects of arachidonic acid are mediated by matrix metalloproteinases. The gene expression profile further suggests that arachidonic acid increases maturation rate of the regenerating scale; in other words, enhances turnover. The zebrafish scale is an excellent model to study how and which fatty acids affect skeletal formation.

  4. Different effects of 7-nitroindazole and L-NAME administered both individually and together on the cardiovascular system of the rat.

    PubMed

    Kristek, F; Drobna, M; Cacanyiova, S

    2015-01-01

    We evaluated the effects of N(G)-nitro-L-arginine methylester (L-NAME) (50 mg/kg/day) and 7-nitroindazole (7NI) (10 mg/kg/day) administered from 10th-16th week of age either individually or together on cardiovascular system of Wistar rats and SHR. Systolic blood pressure (sBP) was measured weekly by the plethysmographic method. For morphological studies, the animals (n=10) were perfused with a fixative (120 mm Hg), and thoracic aorta and carotid and coronary arteries were processed for electron microscopy. For functional investigation (n=10), aortic rings were used in an organ bath. In Wistar rats, L-NAME evoked an increase of sBP; hypertrophy of the heart and arterial walls; an increase in cross-sectional areas (CSA) of endothelial cells (EC), muscle cells (SMC), extracellular matrix (ECM), and a decrease in acetylcholine-induced endothelial-dependent relaxation (EDR). 7NI evoked sBP-independent hypotrophy of the heart and arterial walls, a decrease in CSA of EC and SMC without affecting the CSA of ECM, and a mild decrease in acetylcholine-induced EDR. 7NI and L-NAME administered together evoked lower effect on BP and trophicity of the heart and all arteries, and a similar decrease in acetylcholine-induced EDR compared to L-NAME alone. In SHR, 7NI did not evoke any effect on the studied parameters.

  5. Effects of a novel ACE inhibitor, 3-(3-thienyl)-l-alanyl-ornithyl-proline, on endothelial vasodilation and hepatotoxicity in l-NAME-induced hypertensive rats

    PubMed Central

    Seth, Mahesh Kumar; Hussain, M Ejaz; Pasha, Santosh; Fahim, Mohammad

    2016-01-01

    Nitric oxide (NO) is a widespread biological mediator involved in many physiological and pathological processes, eg, in the regulation of vascular tone and hypertension. Chronic inhibition of NO synthase by NG-nitro-l-arginine methyl ester (l-NAME) hydrochloride results in the development of hypertension accompanied by an increase in vascular responsiveness to adrenergic stimuli. Recently, we developed a novel sulfur-containing angiotensin-converting enzyme inhibitor: 3-(3-thienyl)-l-alanyl-ornithyl-proline (TOP). Our previous studies indicated a superior nature of the molecule as an antihypertensive agent in spontaneously hypertensive rats (showing the involvement of renin–angiotensin–aldosterone system) in comparison to captopril. The aim of the present study was to investigate the effect of TOP on NO pathway in l-NAME-induced hypertensive rats, and captopril was included as the standard treatment group. Treatment with both TOP (20 mg/kg) and captopril (40 mg/kg) prevented the development of hypertension in l-NAME model, but TOP showed better restoration of NO and normal levels of angiotensin-converting enzyme. In addition, in vitro vasorelaxation assay showed an improvement in endothelium-dependent vasodilation in both the cases. Further, the biochemical (malondialdehyde, alanine aminotransferase, and aspartate aminotransferase) and the histopathological effects of TOP on rat liver tissues revealed a protective nature of TOP in comparison to captopril in the l-NAME model. In conclusion, TOP at 50% lesser dose than captopril was found to be better in the l-NAME model. PMID:27143859

  6. Effects of midodrine and L-NAME on systemic and cerebral hemodynamics during cognitive activation in spinal cord injury and intact controls.

    PubMed

    Wecht, Jill M; Weir, Joseph P; Radulovic, Miroslav; Bauman, William A

    2016-02-01

    We previously showed that increases in mean arterial pressure (MAP) following administration of midodrine hydrochloride (MH) and nitro-L-arginine methyl ester (L-NAME) resulted in increased mean cerebral blood flow velocity (MFV) during head-up tilt in hypotensive individuals with spinal cord injury (SCI) and question if this same association was evident during cognitive activation. Herein, we report MAP and MFV during two serial subtraction tasks (SSt) given before (predrug) and after (postdrug) administration of MH; (10 mg), L-NAME (1 mg/kg) or no drug (ND) in 15 subjects with SCI compared to nine able-bodied (AB) controls. Three-way factorial analysis of variance (ANOVA) models were used to determine significant main and interaction effects for group (SCI, AB), visit (MH, L-NAME, ND), and time (predrug, postdrug) for MAP and MFV during the two SSt. The three-way interaction was significant for MAP (F = 4.262; P = 0.020); both MH (30 ± 26 mmHg; P < 0.05) and L-NAME (27 ± 22 mmHg; P < 0.01) significantly increased MAP in the SCI group, but not in the AB group. There was a significant visit by time interaction for MFV suggesting an increase from predrug to postdrug following L-NAME (6 ± 8 cm/sec; P < 0.05) and MH (4 ± 7 cm/sec; P < 0.05), regardless of study group, with little change following ND (3 ± 3 cm/sec). The relationship between change in MAP and MFV was significant in the SCI group following administration of MH (r(2) = 0.38; P < 0.05) and L-NAME (r(2) = 0.32; P < 0.05). These antihypotensive agents, at the doses tested, raised MAP, which was associated with an increase MFV during cognitive activation in hypotensive subjects with SCI. PMID:26869679

  7. Effects of midodrine and L-NAME on systemic and cerebral hemodynamics during cognitive activation in spinal cord injury and intact controls.

    PubMed

    Wecht, Jill M; Weir, Joseph P; Radulovic, Miroslav; Bauman, William A

    2016-02-01

    We previously showed that increases in mean arterial pressure (MAP) following administration of midodrine hydrochloride (MH) and nitro-L-arginine methyl ester (L-NAME) resulted in increased mean cerebral blood flow velocity (MFV) during head-up tilt in hypotensive individuals with spinal cord injury (SCI) and question if this same association was evident during cognitive activation. Herein, we report MAP and MFV during two serial subtraction tasks (SSt) given before (predrug) and after (postdrug) administration of MH; (10 mg), L-NAME (1 mg/kg) or no drug (ND) in 15 subjects with SCI compared to nine able-bodied (AB) controls. Three-way factorial analysis of variance (ANOVA) models were used to determine significant main and interaction effects for group (SCI, AB), visit (MH, L-NAME, ND), and time (predrug, postdrug) for MAP and MFV during the two SSt. The three-way interaction was significant for MAP (F = 4.262; P = 0.020); both MH (30 ± 26 mmHg; P < 0.05) and L-NAME (27 ± 22 mmHg; P < 0.01) significantly increased MAP in the SCI group, but not in the AB group. There was a significant visit by time interaction for MFV suggesting an increase from predrug to postdrug following L-NAME (6 ± 8 cm/sec; P < 0.05) and MH (4 ± 7 cm/sec; P < 0.05), regardless of study group, with little change following ND (3 ± 3 cm/sec). The relationship between change in MAP and MFV was significant in the SCI group following administration of MH (r(2) = 0.38; P < 0.05) and L-NAME (r(2) = 0.32; P < 0.05). These antihypotensive agents, at the doses tested, raised MAP, which was associated with an increase MFV during cognitive activation in hypotensive subjects with SCI.

  8. Arachidonic acid stimulates /sup 45/calcium efflux and HPL release in isolated trophoblast cells

    SciTech Connect

    Zeitler, P.; Murphy, E.; Handwerger, S.

    1986-01-13

    Previous investigations from this laboratory have indicated that arachidonic acid stimulates a rapid, dose-dependent and reversible increase in hPL release which is not dependent on cyclooxygenase or lipoxygenase metabolism. To investigate further the mechanism by which arachidonic acid stimulates the release of hPL, the effect of arachidonic acid on the release of /sup 45/Ca from perifused cells prelabelled with /sup 45/Ca was examined in an enriched cell culture population of term human syncytiotrophoblast. Arachidonic acid (10-100 ..mu..M) stimulated a dose-dependent, rapid, and reversible increase in the release of both /sup 45/Ca and hPL from the perifused placental cells. On the other hand, palmitic acid had little effect on either hPL release or /sup 45/Ca release even at concentrations as high as 100 ..mu..M. Ionophore A23187 (1-10..mu..M) also stimulated a dose-dependent and reversible increase in hPL release. Since arachidonic acid increases the mobilization of cellular calcium, as reflected by the increased /sup 45/calcium efflux, and since an increase in the intracellular calcium concentration appears to stimulate an increase in hPL release, these results suggest that the stimulation of hPL release by arachidonic acid may be due, at least in part, to the effects of the fatty acid on cellular calcium mobilization. 26 references, 5 figures.

  9. Activation and regulation of arachidonic acid release in rabbit peritoneal neutrophils

    SciTech Connect

    Tao, W.

    1988-01-01

    Arachidonic acid release in rabbit neutrophils can be enhanced by the addition of chemotactic fMet-Leu-Phe, platelet-activating factor, PAF, or the calcium ionophore A23187. Over 80% of the release ({sup 3}H)arachidonic acid comes from phosphatidylcholine and phosphatidylinositol. The release is dose-dependent and increases with increasing concentration of the stimulus. The A23187-induced release increases with increasing time of the stimulation. ({sup 3}H)arachidonic acid release, but not the rise in the concentration of intracellular calcium, is inhibited in pertussis toxin-treated neutrophils stimulated with PAF. The ({sup 3}H)arachidonic acid released by A23187 is potentiated while that release by fMET-Leu-Phe or PAF is inhibited in phorbol 12-myristate 13-acetate, PMA, treated rabbit neutrophils. The protein kinase C inhibitor 1-(5-isoquinoline sulfonyl)-2-methylpiperazine, H-7, has no effect on the potentiation by PMA of the A23187-induced release, it prevents the inhibition by PMA of the release produced by PAF or fMet-Leu-Phe. In addition, PMA increases arachidonic acid release in H-7-treated cells stimulated with fMet-Leu-Phe. The diacylglycerol kinase inhibitor R59022 increases the level of diacylglycerol in neutrophils stimulated with fMet-Leu-Phe. Furthermore, R59022 potentiates ({sup 3}H) arachidonic acid release produced by fMet-Leu-Phe. This potentiation is not inhibited by H-7, in fact, it is increased in H-7-treated neutrophils.

  10. Effect of L-arginine and L-NAME on Kidney Tissue Damage in Rats after 24 h of Bilateral Ureteral Obstruction

    PubMed Central

    Tirani, Shahnaz Amani; Pezeshki, Zahra; Nematbakhsh, Mehdi; Nasri, Hamid; Talebi, Ardeshir

    2015-01-01

    Background: Bilateral ureteral obstruction (BUO) affects renal function adversely. Previous investigations have implied that nitric oxide (NO) improves renal function in obstructive nephropathy. The aim of the current study was to investigate the role of NO precursor, L-arginine, and NO blocker agent, L-NAME on kidney tissue damage in rats after 24 h of BUO. Methods: Forty Wistar rats (18 male, 22 female) were divided into four groups as follows; group 1: Sham or negative control group that received saline 3 days prior to the sham operation, group 2: Vehicle or positive control group that received saline 3 days prior to BUO, and groups 3 and 4: L-arginine and L-NAME groups that were treated same as group 2 except L-arginine (300 mg/kg) and L-NAME (4 mg/kg) instead of saline, respectively. Twenty-four hours after obstruction, the serum levels of blood urea nitrogen (BUN), creatinine (Cr), nitrite, and malondialdehyde (MDA) as well as kidney tissue levels of nitrite and MDA were measured and histopathological studies were done on left kidney. Results: The serum levels of BUN and Cr and kidney and body weights increased and the tissue levels of MDA and nitrite decreased significantly in all BUO groups (P < 0.05). However, the tissue damage score was significantly lower in the L-arginine treated group in comparison to the vehicle and L-NAME groups (P < 0.05). As expected, the serum level of nitrite significantly increased in the L-arginine group (P < 0.05). Conclusions: Endogenous NO donor; L-arginine, may protect the kidney tissue against BUO. However, this renoprotective role of L-arginine did not attenuate the increased kidney function markers (BUN and Cr) induced by obstruction. PMID:26288704

  11. Synergistic Antihypertensive Effect of Carthamus tinctorius L. Extract and Captopril in L-NAME-Induced Hypertensive Rats via Restoration of eNOS and AT₁R Expression.

    PubMed

    Maneesai, Putcharawipa; Prasarttong, Patoomporn; Bunbupha, Sarawoot; Kukongviriyapan, Upa; Kukongviriyapan, Veerapol; Tangsucharit, Panot; Prachaney, Parichat; Pakdeechote, Poungrat

    2016-03-01

    This study examined the effect of Carthamus tinctorius (CT) extract plus captopril treatment on blood pressure, vascular function, nitric oxide (NO) bioavailability, oxidative stress and renin-angiotensin system (RAS) in N(ω)-Nitro-l-arginine methyl ester (l-NAME)-induced hypertension. Rats were treated with l-NAME (40 mg/kg/day) for five weeks and given CT extract (75 or 150 or 300 or 500 mg/kg/day): captopril (5 mg/kg/day) or CT extract (300 mg/kg/day) plus captopril (5 mg/kg/day) for two consecutive weeks. CT extract reduced blood pressure dose-dependently, and the most effective dose was 300 mg/kg/day. l-NAME-induced hypertensive rats showed abnormalities including high blood pressure, high vascular resistance, impairment of acetylcholine-induced vasorelaxation in isolated aortic rings and mesenteric vascular beds, increased vascular superoxide production and plasma malondialdehyde levels, downregulation of eNOS, low level of plasma nitric oxide metabolites, upregulation of angiotensin II type 1 receptor and increased plasma angiotensin II. These abnormalities were alleviated by treatment with either CT extract or captopril. Combination treatment of CT extract and captopril normalized all the abnormalities found in hypertensive rats except endothelial dysfunction. These data indicate that there are synergistic antihypertensive effects of CT extract and captopril. These effects are likely mediated by their anti-oxidative properties and their inhibition of RAS.

  12. Synergistic Antihypertensive Effect of Carthamus tinctorius L. Extract and Captopril in l-NAME-Induced Hypertensive Rats via Restoration of eNOS and AT1R Expression

    PubMed Central

    Maneesai, Putcharawipa; Prasarttong, Patoomporn; Bunbupha, Sarawoot; Kukongviriyapan, Upa; Kukongviriyapan, Veerapol; Tangsucharit, Panot; Prachaney, Parichat; Pakdeechote, Poungrat

    2016-01-01

    This study examined the effect of Carthamus tinctorius (CT) extract plus captopril treatment on blood pressure, vascular function, nitric oxide (NO) bioavailability, oxidative stress and renin-angiotensin system (RAS) in Nω-Nitro-l-arginine methyl ester (l-NAME)-induced hypertension. Rats were treated with l-NAME (40 mg/kg/day) for five weeks and given CT extract (75 or 150 or 300 or 500 mg/kg/day): captopril (5 mg/kg/day) or CT extract (300 mg/kg/day) plus captopril (5 mg/kg/day) for two consecutive weeks. CT extract reduced blood pressure dose-dependently, and the most effective dose was 300 mg/kg/day. l-NAME-induced hypertensive rats showed abnormalities including high blood pressure, high vascular resistance, impairment of acetylcholine-induced vasorelaxation in isolated aortic rings and mesenteric vascular beds, increased vascular superoxide production and plasma malondialdehyde levels, downregulation of eNOS, low level of plasma nitric oxide metabolites, upregulation of angiotensin II type 1 receptor and increased plasma angiotensin II. These abnormalities were alleviated by treatment with either CT extract or captopril. Combination treatment of CT extract and captopril normalized all the abnormalities found in hypertensive rats except endothelial dysfunction. These data indicate that there are synergistic antihypertensive effects of CT extract and captopril. These effects are likely mediated by their anti-oxidative properties and their inhibition of RAS. PMID:26938552

  13. Ellagic Acid Prevents L-NAME-Induced Hypertension via Restoration of eNOS and p47phox Expression in Rats.

    PubMed

    Berkban, Thewarid; Boonprom, Pattanapong; Bunbupha, Sarawoot; Welbat, Jariya Umka; Kukongviriyapan, Upa; Kukongviriyapan, Veerapol; Pakdeechote, Poungrat; Prachaney, Parichat

    2015-07-01

    The effect of ellagic acid on oxidative stress and hypertension induced by Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME) was investigated. Male Sprague-Dawley rats were administrated with L-NAME (40 mg/kg/day) for five weeks. L-NAME induced high systolic blood pressure (SBP) and increased heart rate (HR), hindlimb vascular resistance (HVR) and oxidative stress. Concurrent treatment with ellagic acid (7.5 or 15 mg/kg) prevented these alterations. Co-treatment with ellagic acid was associated with up-regulation of endothelial nitric oxide synthase (eNOS) protein production and alleviation of oxidative stress as indicated by decreased superoxide production in the vascular tissue, reduced plasma malondialdehyde levels, reduced NADPH oxidase subunit p47phox expression and increased plasma nitrate/nitrite levels. Our results indicate that ellagic acid attenuates hypertension by reducing NADPH oxidase subunit p47phox expression, which prevents oxidative stress and restores NO bioavailability. PMID:26133972

  14. Synergistic Antihypertensive Effect of Carthamus tinctorius L. Extract and Captopril in L-NAME-Induced Hypertensive Rats via Restoration of eNOS and AT₁R Expression.

    PubMed

    Maneesai, Putcharawipa; Prasarttong, Patoomporn; Bunbupha, Sarawoot; Kukongviriyapan, Upa; Kukongviriyapan, Veerapol; Tangsucharit, Panot; Prachaney, Parichat; Pakdeechote, Poungrat

    2016-03-01

    This study examined the effect of Carthamus tinctorius (CT) extract plus captopril treatment on blood pressure, vascular function, nitric oxide (NO) bioavailability, oxidative stress and renin-angiotensin system (RAS) in N(ω)-Nitro-l-arginine methyl ester (l-NAME)-induced hypertension. Rats were treated with l-NAME (40 mg/kg/day) for five weeks and given CT extract (75 or 150 or 300 or 500 mg/kg/day): captopril (5 mg/kg/day) or CT extract (300 mg/kg/day) plus captopril (5 mg/kg/day) for two consecutive weeks. CT extract reduced blood pressure dose-dependently, and the most effective dose was 300 mg/kg/day. l-NAME-induced hypertensive rats showed abnormalities including high blood pressure, high vascular resistance, impairment of acetylcholine-induced vasorelaxation in isolated aortic rings and mesenteric vascular beds, increased vascular superoxide production and plasma malondialdehyde levels, downregulation of eNOS, low level of plasma nitric oxide metabolites, upregulation of angiotensin II type 1 receptor and increased plasma angiotensin II. These abnormalities were alleviated by treatment with either CT extract or captopril. Combination treatment of CT extract and captopril normalized all the abnormalities found in hypertensive rats except endothelial dysfunction. These data indicate that there are synergistic antihypertensive effects of CT extract and captopril. These effects are likely mediated by their anti-oxidative properties and their inhibition of RAS. PMID:26938552

  15. Neuroprotective Role of L-NG-Nitroarginine Methyl Ester (L-NAME) against Chronic Hypobaric Hypoxia with Crowding Stress (CHC) Induced Depression-Like Behaviour.

    PubMed

    Deep, Satya Narayan; Baitharu, Iswar; Sharma, Apurva; Gurjar, Anoop Kishor Singh; Prasad, Dipti; Singh, Shashi Bala

    2016-01-01

    Improper neuroimmune responses following chronic stress exposure have been reported to cause neuronal dysfunctions leading to memory impairment, anxiety and depression like behaviours. Though several factors affecting microglial activation and consequent alteration in neuro-inflammatory responses have been well studied, role of NO and its association with microglia in stress induced depression model is yet to be explored. In the present study, we validated combination of chronic hypobaric hypoxia and crowding (CHC) as a stress model for depression and investigated the role of chronic stress induced elevated nitric oxide (NO) level in microglia activation and its effect on neuro-inflammatory responses in brain. Further, we evaluated the ameliorative effect of L-NG-Nitroarginine Methyl Ester (L-NAME) to reverse the stress induced depressive mood state. Four groups of male Sprague Dawley rat were taken and divided into control and CHC stress exposed group with and without treatment of L-NAME. Depression like behaviour and anhedonia in rats were assessed by Forced Swim Test (FST) and Sucrose Preference Test (SPT). Microglial activation was evaluated using Iba-1 immunohistochemistry and proinflammatory cytokines were assessed in the hippocampal region. Our result showed that exposure to CHC stress increased the number of active microglia with corresponding increase in inflammatory cytokines and altered behavioural responses. The inhibition of NO synthesis by L-NAME during CHC exposure decreased the number of active microglia in hippocampus as evident from decreased Iba-1 positive cells. Further, L-NAME administration decreased pro-inflammatory cytokines in hippocampus and improved behaviour of rats. Our study demonstrate that stress induced elevation of NO plays pivotal role in altered microglial activation and consequent neurodegenerative processes leading to depression like behaviour in rat.

  16. Neuroprotective Role of L-NG-Nitroarginine Methyl Ester (L-NAME) against Chronic Hypobaric Hypoxia with Crowding Stress (CHC) Induced Depression-Like Behaviour.

    PubMed

    Deep, Satya Narayan; Baitharu, Iswar; Sharma, Apurva; Gurjar, Anoop Kishor Singh; Prasad, Dipti; Singh, Shashi Bala

    2016-01-01

    Improper neuroimmune responses following chronic stress exposure have been reported to cause neuronal dysfunctions leading to memory impairment, anxiety and depression like behaviours. Though several factors affecting microglial activation and consequent alteration in neuro-inflammatory responses have been well studied, role of NO and its association with microglia in stress induced depression model is yet to be explored. In the present study, we validated combination of chronic hypobaric hypoxia and crowding (CHC) as a stress model for depression and investigated the role of chronic stress induced elevated nitric oxide (NO) level in microglia activation and its effect on neuro-inflammatory responses in brain. Further, we evaluated the ameliorative effect of L-NG-Nitroarginine Methyl Ester (L-NAME) to reverse the stress induced depressive mood state. Four groups of male Sprague Dawley rat were taken and divided into control and CHC stress exposed group with and without treatment of L-NAME. Depression like behaviour and anhedonia in rats were assessed by Forced Swim Test (FST) and Sucrose Preference Test (SPT). Microglial activation was evaluated using Iba-1 immunohistochemistry and proinflammatory cytokines were assessed in the hippocampal region. Our result showed that exposure to CHC stress increased the number of active microglia with corresponding increase in inflammatory cytokines and altered behavioural responses. The inhibition of NO synthesis by L-NAME during CHC exposure decreased the number of active microglia in hippocampus as evident from decreased Iba-1 positive cells. Further, L-NAME administration decreased pro-inflammatory cytokines in hippocampus and improved behaviour of rats. Our study demonstrate that stress induced elevation of NO plays pivotal role in altered microglial activation and consequent neurodegenerative processes leading to depression like behaviour in rat. PMID:27082990

  17. Neuroprotective Role of L-NG-Nitroarginine Methyl Ester (L-NAME) against Chronic Hypobaric Hypoxia with Crowding Stress (CHC) Induced Depression-Like Behaviour

    PubMed Central

    Deep, Satya Narayan; Baitharu, Iswar; Sharma, Apurva; Gurjar, Anoop Kishor Singh; Prasad, Dipti; Singh, Shashi Bala

    2016-01-01

    Improper neuroimmune responses following chronic stress exposure have been reported to cause neuronal dysfunctions leading to memory impairment, anxiety and depression like behaviours. Though several factors affecting microglial activation and consequent alteration in neuro-inflammatory responses have been well studied, role of NO and its association with microglia in stress induced depression model is yet to be explored. In the present study, we validated combination of chronic hypobaric hypoxia and crowding (CHC) as a stress model for depression and investigated the role of chronic stress induced elevated nitric oxide (NO) level in microglia activation and its effect on neuro-inflammatory responses in brain. Further, we evaluated the ameliorative effect of L-NG-Nitroarginine Methyl Ester (L-NAME) to reverse the stress induced depressive mood state. Four groups of male Sprague Dawley rat were taken and divided into control and CHC stress exposed group with and without treatment of L-NAME. Depression like behaviour and anhedonia in rats were assessed by Forced Swim Test (FST) and Sucrose Preference Test (SPT). Microglial activation was evaluated using Iba-1 immunohistochemistry and proinflammatory cytokines were assessed in the hippocampal region. Our result showed that exposure to CHC stress increased the number of active microglia with corresponding increase in inflammatory cytokines and altered behavioural responses. The inhibition of NO synthesis by L-NAME during CHC exposure decreased the number of active microglia in hippocampus as evident from decreased Iba-1 positive cells. Further, L-NAME administration decreased pro-inflammatory cytokines in hippocampus and improved behaviour of rats. Our study demonstrate that stress induced elevation of NO plays pivotal role in altered microglial activation and consequent neurodegenerative processes leading to depression like behaviour in rat. PMID:27082990

  18. (-)-Epicatechin prevents alterations in the metabolism of superoxide anion and nitric oxide in the hearts of L-NAME-treated rats.

    PubMed

    Piotrkowski, Barbara; Calabró, Valeria; Galleano, Mónica; Fraga, César G

    2015-01-01

    The aim of this work was to evaluate the effects of (-)-epicatechin administration in the heart of a rat model with reduced NO production that follows a short-term treatment with L-NAME. Sprague-Dawley rats were treated for 4 d with L-NAME in the absence or presence of (-)-epicatechin in the diet. The redox status in cardiac tissue was improved by (-)-epicatechin administration. L-NAME treatment induced a decrease in NO synthase activity (-62%, p<0.05) and an increase in NADPH-dependent superoxide anion production (+300%, p<0.05) that were totally prevented by (-)-epicatechin administration. These effects of (-)-epicatechin were associated with a higher endothelial NO synthase phosphorylation at an activation site and a reduced expression of the regulatory subunit, p47(phox), suggesting the involvement of posttranslational mechanisms in (-)-epicatechin action. Thus, the (-)-epicatechin treatment would restore NO steady state levels in vivo through effects on both, its synthesis and degradation via the reaction with superoxide anion. The fact that (-)-epicatechin is commonly present in human diet makes this compound a reasonable explanation for the positive cardiovascular effects of a high consumption of fruits and vegetables. PMID:25361437

  19. Correlation between arachidonic acid oxygenation and luminol-induced chemiluminescence in neutrophils: inhibition by diethyldithiocarbamate.

    PubMed

    Chabannes, B; Perraut, C; El Habib, R; Moliere, P; Pacheco, Y; Lagarde, M

    1997-04-01

    Neutrophils from allergic subjects were hypersensitive to stimulation by low calcium ionophore concentration (0.15 microM), resulting in an increased formation of leukotriene B4 (LTB4), 5S-hydroxy-6,8,11,14-(E,Z,Z,Z)-eicosatetraenoic acid (5-HETE), and other arachidonic acid metabolites through the 5-lipoxygenase pathway. In parallel, luminol-dependent chemiluminescence was also higher in neutrophils from allergic patients at the basal state and after stimulation by calcium ionophore, revealing an enhancement of radical oxygen species and peroxide production. The activity of glutathione peroxidase, the main enzyme responsible for hydroperoxide reduction, was lowered in these cells. Diethyl-dithiocarbamate (DTC) induced a concentration-dependent decrease in chemiluminescence and arachidonic acid metabolism after neutrophil stimulation. These data show that the elevation of arachidonic acid metabolism in neutrophils from allergic patients is strongly correlated with oxidative status. This elevation may be the consequence of an increased cellular hydroperoxide known to activate 5-lipoxygenase (5-LOX) activity and/or an increased arachidonic acid availability, due either to phospholipase A2 (PLA2) activation or inhibition of arachidonate reesterification into phospholipids. Lowering this oxidative status was associated with a concomitant decrease of this metabolism. Our results suggest that the effect of DTC may be the consequence of an inhibition of peroxyl radical and cellular lipid hydroperoxide production. Thus, DTC may modulate arachidonic acid metabolism in neutrophils by modulating the cellular hydroperoxide level.

  20. Vasopressin induces release of arachidonic acid from vascular smooth muscle cells

    SciTech Connect

    Grillone, L.R.; Clark, M.A.; Heckman, G.; Schmidt, D.; Stassen, F.L.; Crooke, S.T.

    1986-05-01

    Cultured smooth muscle cells (A-10), derived from rat thoracic aorta, have vascular (V/sub 1/) vasopressin receptors. They have previously shown that these receptors mediate phosphatidylinositol turnover, Ca/sup 2 +/ efflux, and inhibition of isoproterenol-induced increases in cAMP. Here they studied the effect of vasopressin on arachidonic acid metabolism of A-10 cells. Cells were incubated for 18-20 hr with (/sup 3/H)-arachidonic acid (80 Ci/mmol). Vasopressin stimulated release of arachidonic acid in a time- and dose-dependent manner. Significant release of arachidonic acid was observed after 4 min with 10/sup -9/ M vasopressin. Maximum release was reached 4 min after addition of 10/sup -7/ M vasopressin (1100 dpm/10/sup 6/ cells). About 800 dmp were released after 1 and 4 min with 10/sup -7/ M and 10/sup -8/ M vasopressin, respectively. The vasopressin-stimulated release of arachidonic acid was blocked by the specific V/sub 1//V/sub 2/ vasopressin antagonist d(CH2)5D-Tyr(Et)VAVP. These data indicate that vascular smooth muscle cells increase arachidonic acid release in response to vasopressin. This response is likely mediated by V/sub 1/ receptors.

  1. Vascular permeabilization by intravenous arachidonate in the rat peritoneal cavity: antagonism by antioxidants.

    PubMed

    Alvarez-Guerra, Miriam; Hannaert, Patrick; Hider, Hamida; Chiavaroli, Carlo; Garay, Ricardo P

    2003-04-11

    Arachidonic acid was investigated for its vascular permeabilizing potential in the rat peritoneal cavity and for its mechanism of action. The antagonistic potential of antioxidants (vitamin E, vitamin C and troxerutin) was also evaluated. Vascular permeability was equated to the rate of extravasation of Evans blue dye from plasma into the peritoneal cavity. Baseline permeability was linear up to 2 h, with a rate constant (k) of 0.0031+/-0.0007 h(-1). Intravenous arachidonate (from 30 microg/kg to 3 mg/kg) induced an immediate, dose-related and significant increase in permeability (ranging from 80% to 150%), which was comparable to the effect induced by similar doses of serotonin. Aspirin (10 mg/kg) reduced the arachidonate-induced permeability by 75%, but interestingly neither the stable thromboxane A(2) receptor agonist U46619 (prostaglandin H(2) endoperoxide epoxymethane) nor prostacyclin was able to increase peritoneal vascular permeability. In contrast, the permeabilizing action of arachidonic acid was very sensitive to antioxidant agents. Thus, vitamin C and the flavonoid compound troxerutin (100 mg/kg) fully abolished arachidonate-induced permeability, whereas vitamin E had only a partial effect (40-100% inhibition). In conclusion, intravenous administration of arachidonic acid strongly enhanced peritoneal vascular permeability in the rat, apparently via free radical generation. This rat peritoneal model can be used to evaluate the in vivo antinflammatory potential of antioxidant drugs.

  2. Dietary saffron reduced the blood pressure and prevented remodeling of the aorta in L-NAME-induced hypertensive rats

    PubMed Central

    Nasiri, Zohreh; Sameni, Hamid Reza; Vakili, Abedin; Jarrahi, Morteza; Khorasani, Mahdi Zahedi

    2015-01-01

    Objective(s): The aim of this study was to investigate the effects of nutritional saffron (Crocus sativus L.) stigma hydroalcoholic extract on blood pressure (BP) and histology of the aorta in normotensive and hypertensive rats. Materials and Methods: Saffron (200 mg/kg/day) was given orally for 5 weeks to normotensive and hypertensive rats. Hypertension was induced by NG-nitro-L-arginine methyl ester (L-NAME; 40 mg/kg/day) administration in drinking water, and BP was measured weekly. Histological examination of the thoracic aorta included staining with hematoxylin and eosin, orcein, and periodic acid Schiff methods. Results: Saffron had no effect on normotensive rats, but on hypertensive rats, prevented BP elevation form the third week of treatment (P<0.001). Furthermore, saffron reduced the cross-section area, media thickness, and elastic lamellae number of the aorta (P<0.05). Conclusion: Nutritional saffron prevented BP increases and remodeling of the aorta in hypertensive rats. It may be useful for preventing hypertension. PMID:26949504

  3. Arachidonate metabolism in bovine gallbladder muscle

    SciTech Connect

    Nakano, M.; Hidaka, T.; Ueta, T.; Ogura, R.

    1983-04-01

    Incubation of (1-/sup 14/C)arachidonic acid (AA) with homogenates of bovine gallbladder muscle generated a large amount of radioactive material having the chromatographic mobility of 6-keto-PGF1 alpha (stable product of PGI2) and smaller amounts of products that comigrated with PGF2 alpha PGE2. Formation of these products was inhibited by the cyclooxygenase inhibitor indomethacin. The major radioactive product identified by thin-layer chromatographic mobility and by gas chromatography - mass spectrometric analysis was found to be 6-keto-PGF1 alpha. The quantitative metabolic pattern of (1-/sup 14/C)PGH2 was virtually identical to that of (1-/sup 14/C)AA. Incubation of arachidonic acid with slices of bovine gallbladder muscle released labile anti-aggregatory material in the medium, which was inhibited by aspirin or 15-hydroperoxy-AA. These results indicate that bovine gallbladder muscle has a considerable enzymatic capacity to produce PGI2 from arachidonic acid.

  4. Transgenic production of arachidonic acid in oilseeds.

    PubMed

    Petrie, James R; Shrestha, Pushkar; Belide, Srinivas; Mansour, Maged P; Liu, Qing; Horne, James; Nichols, Peter D; Singh, Surinder P

    2012-02-01

    We describe a transgenic microalgal Δ9-elongase pathway transformed in both Brassica napus and Arabidopsis thaliana seed resulting in the production of arachidonic acid (ARA). This pathway is noteworthy for both the production of ARA in seed tissue and the low levels of intermediate C20 fatty acids that accumulate. We also demonstrate that the arachidonic acid is naturally enriched at the sn2 position in triacylglycerol. This is the first report of ARA production by the Δ9-elongase pathway in an oilseed.

  5. Involvement of K+ channel permeability changes in the L-NAME and indomethacin resistant part of adenosine-5′-O-(2-thiodiphosphate)-induced relaxation of pancreatic vascular bed

    PubMed Central

    Hillaire-Buys, D; Chapal, J; Linck, N; Blayac, J P; Petit, P; Loubatières-Mariani, M M

    1998-01-01

    We have previously demonstrated that adenosine-5′-O-(2-thiodiphosphate) (ADPβS), a potent P2Y-purinoceptor agonist, relaxed pancreatic vasculature not only through prostacyclin (PGI2) and nitric oxide (NO) release from the endothelium but also through other mechanism(s). In this study, we investigated the effects of an inhibitor of the Na+/K+ pump, of ATP-sensitive K+ (KATP) channels and of small (SKCa) or large (BKCa) conductance Ca2+-activated K+ channels. Experiments were performed at basal tone and during the inhibition of NO synthase and cyclo-oxygenase.In control conditions, ADPβS (15 μM) induced an initial transient vasoconstriction followed by a progressive and sustained vasodilatation. In the presence of Nω-nitro-L-arginine methyl ester (L-NAME, 200 μM) the transient vasoconstriction was reversed into a one minute vasodilator effect, which was then followed by a progressive and sustained vasodilatation similar to that observed with ADPβS alone. The addition of indomethacin (10 μM) did not significantly modify the profile of ADPβS-induced vasodilatation.Ouabain (100 μM) decreased basal pancreatic flow rate and did not modify ADPβS-induced relaxation. This inhibitor of the Na+/K+ pump increased the pancreatic vasoconstriction induced by L-NAME or by the co-administration of L-NAME and indomethacin. Ouabain did not modify either the L-NAME or the L-NAME/indomethacin resistant part of the ADPβS vasodilatation.The KATP inhibitor tolbutamide (185 μM) did not significantly modify basal pancreatic flow rate and ADPβS-induced relaxation. This inhibitor which did not change L-NAME-induced vasoconstriction, significantly diminished the L-NAME resistant part of ADPβS-induced vasodilatation. Tolbutamide intensified the vasoconstriction induced by the co-administration of L-NAME and indomethacin. In contrast, the L-NAME/indomethacin resistant part of ADPβS vasodilatation was not changed by the closure of KATP.The SKCa inhibitor apamin (0.1

  6. Effects of omega-3 fatty acids on vascular smooth muscle cells: reduction in arachidonic acid incorporation into inositol phospholipids.

    PubMed

    Yerram, N R; Spector, A A

    1989-07-01

    A rapid increase in arachidonic acid incorporation into phosphatidylinositol (PI) occurred following exposure of cultured porcine pulmonary artery smooth muscle cells to calcium ionophore A23187. This response was specific for PI and phosphatidic acid; none of the other phosphoglycerides showed any increase in arachidonic acid incorporation. The incorporation of [3H]inositol also was increased, indicating that complete synthesis of PI rather than only fatty acylation occurred in response to the ionophore. The presence of omega-3 fatty acids, especially eicosapentaenoic acid (EPA), reduced arachidonic acid but not inositol incorporation into PI. Stimulated incorporation of EPA also occurred under these conditions, suggesting that EPA replaces arachidonic acid in the newly synthesized pool of PI. Although much less arachidonic acid was incorporated into the polyphosphoinositides following exposure to the ionophore, arachidonic acid incorporation into these phosphorylated derivatives also decreased when EPA was present. These findings suggest that when omega-3 fatty acids are available, less arachidonic acid is channeled into the inositol phospholipids of activated smooth muscle cells because of replacement by EPA. This may represent a mechanism whereby omega-3 fatty acids, especially EPA, can accumulate in the metabolically active pools of inositol phospholipids and thereby possibly influence the properties or responsiveness of vascular smooth muscle.

  7. L-NAME, a nitric oxide synthase inhibitor, as a potential countermeasure to post-suspension hypotension in rats

    NASA Technical Reports Server (NTRS)

    Bayorh, M. A.; Socci, R. R.; Watts, S.; Wang, M.; Eatman, D.; Emmett, N.; Thierry-Palmer, M.

    2001-01-01

    A large number of astronauts returning from spaceflight experience orthostatic hypotension. This hypotension may be due to overproduction of vasodilatory mediators, such as nitric oxide (NO) and prostaglandins. To evaluate the role of the NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) as a countermeasure against the post-suspension reduction in mean arterial pressure (MAP), we assessed the cardiovascular responses and vascular reactivity to 7-day 30 degrees tail-suspension and a subsequent 6 hr post-suspension period in conscious rats. After a pre-suspension reading, direct MAP and heart rate (HR) were measured daily and every 2 hrs post-suspension. The NO synthase inhibitor L-NAME (20 mg/kg, i.v.), or saline, were administered after the 7th day reading prior to release from suspension and at 2 and 4 hrs post-suspension. At 6 hrs post-suspension, vascular reactivity was assessed. While MAP did not change during the suspension period, it was reduced post-suspension. Heart rate was not significantly altered. L-NAME administration reversed the post-suspension reduction in MAP. In addition, the baroreflex sensitivity for heart rate was modified by L-NAME. Thus, the post-suspension reduction in MAP may be due to overproduction of NO and altered baroreflex activity.

  8. Maitotoxin: Effects on calcium channels, phosphoinositide breakdown, and arachidonate release in pheochromocytoma PC12 cells

    SciTech Connect

    Choi, O.H.; Padgett, W.L.; Nishizawa, Y.; Gusovsky, F.; Yasumoto, T.; Daly, J.W. )

    1990-02-01

    Maitotoxin (MTX) increases formation of (3H)inositol phosphates from phosphoinositides and release of (3H)arachidonic acid from phospholipids in pheochromocytoma PC12 cells. Formation of (3H)inositol phosphates is detected within 1 min of incubation even with concentrations as low as 0.3 ng/ml (90 pm) MTX, whereas release of (3H)arachidonic acid is not detected until 20 min even with concentrations as high as 1 ng/ml (300 pm) MTX. Stimulation of arachidonic acid release can be detected at 0.03 ng/ml (9 pm) MTX, whereas 0.1 ng/ml (30 pm) MTX is the threshold for detection of phosphoinositide breakdown. Organic and inorganic calcium channel blockers, except Cd2+ and a high concentration of Mn2+, have no effect on MTX-elicited phosphoinositide breakdown, whereas inorganic blockers (e.g., Co2+, Mn2+, Cd2+), but not organic blockers (nifedipine, verapamil, diltiazem), inhibit MTX-stimulated arachidonic acid release. All calcium channel blockers, however, inhibited MTX-elicited influx of 45Ca2+ and the MTX-elicited increase in internal Ca2+ measured with fura-2 was markedly reduced by nifedipine. MTX-elicited phosphoinositide breakdown and arachidonic acid release are abolished or reduced, respectively, in the absence of extracellular calcium plus chelating agent. The calcium ionophore A23187 has little or no effect alone but, in combination with MTX, A23187 inhibits MTX-elicited phosphoinositide breakdown and enhances arachidonic acid release, the latter even in the absence of extracellular calcium. The results suggest that different sites and/or mechanisms are involved in stimulation of calcium influx, breakdown of phosphoinositides, and release of arachidonic acid by MTX.

  9. Effects of Diclofenac, L-NAME, L-Arginine, and Pentadecapeptide BPC 157 on Gastrointestinal, Liver, and Brain Lesions, Failed Anastomosis, and Intestinal Adaptation Deterioration in 24 Hour-Short-Bowel Rats.

    PubMed

    Lojo, Nermin; Rasic, Zarko; Zenko Sever, Anita; Kolenc, Danijela; Vukusic, Darko; Drmic, Domagoj; Zoricic, Ivan; Sever, Marko; Seiwerth, Sven; Sikiric, Predrag

    2016-01-01

    Stable gastric pentadecapeptide BPC 157 was previously used to ameliorate wound healing following major surgery and counteract diclofenac toxicity. To resolve the increasing early risks following major massive small bowel resectioning surgery, diclofenac combined with nitric oxide (NO) system blockade was used, suggesting therapy with BPC 157 and the nitric oxide synthase (NOS substrate) L-arginine, is efficacious. Immediately after anastomosis creation, short-bowel rats were untreated or administered intraperitoneal diclofenac (12 mg/kg), BPC 157 (10 μg/kg or 10 ng/kg), L-NG-nitroarginine methyl ester (L-NAME, 5 mg/kg), L-arginine (100 mg/kg) alone or combined, and assessed 24 h later. Short-bowel rats exhibited poor anastomosis healing, failed intestine adaptation, and gastrointestinal, liver, and brain lesions, which worsened with diclofenac. This was gradually ameliorated by immediate therapy with BPC 157 and L-arginine. Contrastingly, NOS-blocker L-NAME induced further aggravation and lesions gradually worsened. Specifically, rats with surgery alone exhibited mild stomach/duodenum lesions, considerable liver lesions, and severe cerebral/hippocampal lesions while those also administered diclofenac showed widespread severe lesions in the gastrointestinal tract, liver, cerebellar nuclear/Purkinje cells, and cerebrum/hippocampus. Rats subjected to surgery, diclofenac, and L-NAME exhibited the mentioned lesions, worsening anastomosis, and macro/microscopical necrosis. Thus, rats subjected to surgery alone showed evidence of deterioration. Furtheremore, rats subjected to surgery and administered diclofenac showed worse symptoms, than the rats subjected to surgery alone did. Rats subjected to surgery combined with diclofenac and L-NAME showed the worst deterioration. Rats subjected to surgery exhibited habitual adaptation of the remaining small intestine, which was markedly reversed in rats subjected to surgery and diclofenac, and those with surgery, diclofenac, and

  10. Effects of Diclofenac, L-NAME, L-Arginine, and Pentadecapeptide BPC 157 on Gastrointestinal, Liver, and Brain Lesions, Failed Anastomosis, and Intestinal Adaptation Deterioration in 24 Hour-Short-Bowel Rats

    PubMed Central

    Lojo, Nermin; Rasic, Zarko; Zenko Sever, Anita; Kolenc, Danijela; Vukusic, Darko; Drmic, Domagoj; Zoricic, Ivan; Sever, Marko; Seiwerth, Sven; Sikiric, Predrag

    2016-01-01

    Stable gastric pentadecapeptide BPC 157 was previously used to ameliorate wound healing following major surgery and counteract diclofenac toxicity. To resolve the increasing early risks following major massive small bowel resectioning surgery, diclofenac combined with nitric oxide (NO) system blockade was used, suggesting therapy with BPC 157 and the nitric oxide synthase (NOS substrate) L-arginine, is efficacious. Immediately after anastomosis creation, short-bowel rats were untreated or administered intraperitoneal diclofenac (12 mg/kg), BPC 157 (10 μg/kg or 10 ng/kg), L-NG-nitroarginine methyl ester (L-NAME, 5 mg/kg), L-arginine (100 mg/kg) alone or combined, and assessed 24 h later. Short-bowel rats exhibited poor anastomosis healing, failed intestine adaptation, and gastrointestinal, liver, and brain lesions, which worsened with diclofenac. This was gradually ameliorated by immediate therapy with BPC 157 and L-arginine. Contrastingly, NOS-blocker L-NAME induced further aggravation and lesions gradually worsened. Specifically, rats with surgery alone exhibited mild stomach/duodenum lesions, considerable liver lesions, and severe cerebral/hippocampal lesions while those also administered diclofenac showed widespread severe lesions in the gastrointestinal tract, liver, cerebellar nuclear/Purkinje cells, and cerebrum/hippocampus. Rats subjected to surgery, diclofenac, and L-NAME exhibited the mentioned lesions, worsening anastomosis, and macro/microscopical necrosis. Thus, rats subjected to surgery alone showed evidence of deterioration. Furtheremore, rats subjected to surgery and administered diclofenac showed worse symptoms, than the rats subjected to surgery alone did. Rats subjected to surgery combined with diclofenac and L-NAME showed the worst deterioration. Rats subjected to surgery exhibited habitual adaptation of the remaining small intestine, which was markedly reversed in rats subjected to surgery and diclofenac, and those with surgery, diclofenac, and

  11. Cannabinoids influence lipid-arachidonic acid pathways in schizophrenia.

    PubMed

    Smesny, Stefan; Rosburg, Timm; Baur, Kati; Rudolph, Nicole; Sauer, Heinrich

    2007-10-01

    Increasing evidence suggests modulating effects of cannabinoids on time of onset, severity, and outcome of schizophrenia. Efforts to discover the underlying pathomechanism have led to the assumption of gene x environment interactions, including premorbid genetical vulnerability and worsening effects of continuing cannabis use. The objective of this cross-sectional study is to investigate the relationship between delta-9-tetrahydrocannabinol intake and niacin sensitivity in schizophrenia patients and healthy controls. Intensity of niacin skin flushing, indicating disturbed prostaglandin-mediated processes, was used as peripheral marker of lipid-arachidonic acid pathways and investigated in cannabis-consuming and nonconsuming schizophrenia patients and in healthy controls. Methylnicotinate was applied in three concentrations onto the forearm skin. Flush response was assessed in 3-min intervals over 15 min using optical reflection spectroscopy. In controls, skin flushing was significantly decreased in cannabis-consuming as compared to nonconsuming individuals. When comparing the nonconsuming subgroups, patients showed significantly decreased flush response. The populations as a whole (patients and controls) showed an inverse association between skin flushing and sum scores of Symptom Check List 90-R. Results demonstrate an impact of long-term cannabis use on lipid-arachidonic acid pathways. Considering pre-existing vulnerability of lipid metabolism in schizophrenia, observed effects of cannabis use support the notion of a gene x environment interaction.

  12. Beneficial effects of Acer okamotoanum sap on L-NAME-induced hypertension-like symptoms in a rat model.

    PubMed

    Yang, Hyun; Hwang, Inho; Koo, Tae-Hyoung; Ahn, Hyo-Jin; Kim, Sun; Park, Mi-Jin; Choi, Won-Sil; Kang, Ha-Young; Choi, In-Gyu; Choi, Kyung-Chul; Jeung, Eui-Bae

    2012-02-01

    The sap of Acer okamotoanum has been termed 'bone-benefit-water' in Korea owing to its mineral and sugar content. In particular, the calcium (Ca) and potassium (K) concentrations of the sap of Acer okamotoanum are 40- and 20-times higher, respectively, than commercial spring water. In the present study, we examined whether Acer okamotoanum sap improves or prevents hypertension-like symptoms in a rat model. Male Sprague-Dawley rats (8-weeks-old) were provided commercial spring water supplemented with 25, 50 or 100% Acer okamotoanum sap, 3% potassium ions (K+) or captopril, and treated daily for 2 weeks with NG-nitro-L-arginine methyl ester (L-NAME; 100 mg/kg/day) by subcutaneous injection, in order to induce hypertensive symptoms. Rats were euthanized 6 h following the final injection. To assess the effect of the sap on hypertension-like symptoms, we examined the mean blood pressure (BP), protein levels and localization of endothelial nitric oxide synthase (eNOS) in the descending aorta of the rats. BP levels were significantly lower in hypertensive rats received 25, 50 and 100% sap compared with rats who were administered only commercial spring water. Protein levels of eNOS were repressed in L-NAME-only-treated rats, but were elevated in the descending aorta of rats administered captopril, K+ water and Acer okamotoanum sap (25, 50 and 100%) up to the level of the sham group provided commercial spring water, and then injected with dimethyl sulfoxide for the same period of time. Localized eNOS protein was abundantly expressed in the perivascular descending aorta adipose tissue of the rats. Taken together, these results demonstrated that the sap of Acer okamotoanum ameliorated high BP induced by L-NAME treatment in a rat model.

  13. Human monocyte differentiation stage affects response to arachidonic acid.

    PubMed

    Escobar-Alvarez, Elizabeth; Pelaez, Carlos A; García, Luis F; Rojas, Mauricio

    2010-01-01

    AA-induced cell death mechanisms acting on human monocytes and monocyte-derived macrophages (MDM), U937 promonocytes and PMA-differentiated U937 cells were studied. Arachidonic acid induced apoptosis and necrosis in monocytes and U937 cells but only apoptosis in MDM and U937D cells. AA increased both types of death in Mycobacterium tuberculosis-infected cells and increased the percentage of TNFalpha+ cells and reduced IL-10+ cells. Experiments blocking these cytokines indicated that AA-mediated death was TNFalpha- and IL-10-independent. The differences in AA-mediated cell death could be explained by high ROS, calpain and sPLA-2 production and activity in monocytes. Blocking sPLA-2 in monocytes and treatment with antioxidants favored M. tuberculosis control whereas AA enhanced M. tuberculosis growth in MDM. Such evidence suggested that AA-modulated effector mechanisms depend on mononuclear phagocytes' differentiation stage.

  14. Inhibiting the transient choroidal thickening response using the nitric oxide synthase inhibitor l-NAME prevents the ameliorative effects of visual experience on ocular growth in two different visual paradigms.

    PubMed

    Nickla, Debora L; Wilken, Erika; Lytle, Grace; Yom, Sung; Mertz, James

    2006-08-01

    It is generally accepted that the increase in choroidal thickness in response to myopic defocus in chicks acts to move the retina towards the image plane. It may also constitute part of the signal cascade in the visual regulation of eye growth. To test this, we used the nitric oxide synthase inhibitor l-NAME to inhibit the defocus induced choroidal thickening under two different visual conditions, and looked at the effects on ocular growth rate. Exp. 1: Deprivation/Vision: chicks were monocularly deprived of form vision with translucent diffusers from day 6 to day 9. In the middle of each day the diffusers were removed for 2 h. One group received an intravitreal injection of 30 microl l-NAME (16 micromole; n=12) prior to the vision, a second group received injections of physiological saline (n=11). Exp. 2: Recovery/Vision: chicks were made myopic by form deprivation from day 6 to day 10. On days 11 to 14 the diffusers were removed for 2 h per day for 4 days to allow eyes to "recover" from the myopia. One group received an injection of l-NAME prior to vision (n=8), the other saline (n=6). Refractive errors were measured with a refractometer at the start (days 6 and 11) and end (days 10 and 15, respectively) of both experiments. Ocular dimensions were measured with high frequency A-scan ultrasonography at the start and end, and on the third experimental day immediately before and after the period of vision. Choroidal retinoic acid synthesis was measured by HPLC. Finally, NO production and scleral proteoglycan synthesis were measured in eyes wearing positive lenses 6 and 24h after an injection of l-NAME. l-NAME prevented the transient vision-induced choroidal thickening in both experiments. Furthermore, l-NAME inhibited the protective effect of brief daily vision: eyes became significantly more myopic than saline controls (exp. 1: -9 D vs -2.7D; exp. 2: -0.9 D vs +4.3 D; p<0.005 for both) and grew faster (change in lens-sclera: exp. 1: 295 vs 158 microm; exp. 2: 147

  15. Ozone-induced alterations in arachidonic acid metabolism in cultured lung cell types

    SciTech Connect

    Madden, M.C.

    1986-01-01

    One of the most sensitive cells to ozone (O/sub 3/) damage is the pulmonary endothelial cell which may mediate the response of the lung to injury by productions of the autacoid prostacyclin (PGl/sub 2/), a metabolite of arachidonic acid. Exposure of endothelial cell cultures to ozone produced a concentration dependent decreases in the synthesis of PGl/sub 2/. Release of /sup 3/H-arachidonic acid from endothelial cells was increased after two hours of 0.3 and 1.0 ppm O/sub 3/ exposure while incubation of cells with 20 ..mu..M and arachidonate (4 min) after exposure resulted in a decreased PGl/sub 2/ synthesis. Cells exposed to 1.0 ppm O/sub 3/ did not have a decreased PGl/sub 2/ production when incubated with 5 ..mu..M PGH/sub 2/ immediately after exposure. These results are consistent with an O/sub 3/-induced inhibition of cyclooxygenase activity. O/sub 3/ exposure (1.0 ppm) produced a rapid decrease in endothelial PGl/sub 2/ synthesis. The data suggest that cyclooxygenase was not inactivated by increased autooxidation due to metabolism of increased free arachidonate. PGl/sub 2/ synthesis returned to control amounts within 12 hours after ozone exposure similar to the recovery time of irreversibly inhibited cyclooxygenase suggesting that recovery was due to de novo synthesis of enzyme. Lipid peroxides and/or hydrogen peroxide (H/sub 2/O/sub 2/) may have caused the inhibition of cyclooxygenase. Incubation of cells with catalase (5 U/ml) protected against the O/sub 3/-induced depression in PGl/sub 2/ synthesis. Exogenously added H/sub 2/O/sub 2/ (greater than or equal to 75 ..mu..M) caused a stimulation of basal PGl/sub 2/ production but depressed arachidonate-stimulated synthesis. O/sub 3/ exposure (2 hr, 1.0 ppm) produced altered metabolism of arachidonate in other important lung cell types, e.g., a decreased PGl/sub 2/ synthesis in smooth muscle cultures. Exposure of lung macrophages to O/sub 3/ caused an increase in almost all arachidonate metabolites produced.

  16. Dietary triacylglycerols with palmitic acid (16:0) in the 2-position increase 16:0 in the 2-position of plasma and chylomicron triacylglycerols, but reduce phospholipid arachidonic and docosahexaenoic acids, and alter cholesteryl ester metabolism in formula-Fed piglets.

    PubMed

    Innis, S M; Dyer, R

    1997-07-01

    Milk triacylglycerols have an unusual fatty acid distribution, with palmitic acid (16:0) esterified predominately at the center (sn-2) position. Other dietary triacylglycerols contain 16:0 predominantly at the sn-1,3 positions. This study was designed to evaluate the effect of formula triacylglycerol fatty acid distribution on the composition and distribution of plasma lipoprotein fatty acids in piglets fed formula containing synthesized triacylglycerols or palm olein oil with about 32 or 4.2% 16:0, respectively, in fatty acids at the sn-2 position, with comparison to piglets fed sow's milk. Feeding formula with 16:0 at the triglyceride sn-2 position or sow's milk resulted in higher chylomicron triacylglycerol sn-2 16:0 than when palm olein was fed. This suggests that dietary triacylglycerol sn-2 position fatty acids are conserved during digestion, absorption and reassembly to chylomicron triacylglycerols. The increased chylomicron triacylglycerol sn-2 position 16:0 in piglets fed synthesized triacylglycerols was accompanied by lower chylomicron triacylglycerol arachidonic and docosahexaenoic acid than in piglets fed formula with palm olein, suggesting an interaction between dietary triacylglycerol saturated fatty acid distribution and (n-6) and (n-3) fatty acid transport.

  17. The nitric oxide synthesis inhibitor L-NAME produces anxiogenic-like effects in the rat elevated plus-maze test, but not in the social interaction test.

    PubMed

    Vale, A L; Green, S; Montgomery, A M; Shafi, S

    1998-01-01

    The effects of the nitric oxide synthase inhibitor, Nw-nitro-L-arginine methyl ester (L-NAME) were investigated in two animal models of anxiety: the elevated plus-maze and the social interaction test. In the elevated plus-maze, L-NAME (12.5-50 mg/kg) had an anxiogenic-like profile as indicated by dose-dependent reductions in the time spent on the open arms, open arm entries, the percentage of open arm entries and head dips, but there was no significant effect on the number of stretch attend postures. In contrast, L-NAME (12.5-50 mg/kg) failed to modify time spent in social interaction but did reduce a measure of vertical activity. The differential effects of L-NAME in the two anxiety paradigms are discussed.

  18. A study of ozone-induced edema in the isolated rat lung in relation to arachidonic acid metabolism, mixed-function oxidases and angiotensin converting enzyme activities.

    PubMed

    Dutta, S; Chatterjee, M; Teknos, T N; Carlson, R W

    1990-01-01

    In order to elucidate the role of arachidonic acid in the pathogenesis of ozone-induced pulmonary edema, isolated rat lungs were exposed to 14C-arachidonic acid in the presence or absence of ozone and the incorporation of radiolabelled arachidonate into pulmonary cell lipids was studied. The perfusates from these studies were also subjected to differential extraction and thin layer chromatography (t.l.c.) to determine synthesis of both cyclo-oxygenase and lipoxygenase products. In the presence of an edemagenic concentration of ozone, isolated lungs incorporated significantly less exogenous arachidonic acid into phosphatidyl choline and phosphatidyl ethanolamine, whereas incorporation into phosphatidyl inositol or serine was not affected. The edemagenic concentration of ozone also increased production of a variety of arachidonic acid metabolites via cyclo-oxygenase and lipoxygenase pathways. In separate studies, a similar ozone exposure did not affect 14CO2 production, resulting from the metabolism of 14C-antipyrine by mixed function oxidases (MFO). Similarly, an edemagenic concentration of ozone did not affect pulmonary angiotensin converting enzyme activity (ACE) as determined by the rate of formation of 14C-hippuric acid from 14C-hippuryl-histidyl-leucine (14C-HHL). Thus, acute ozone exposure is specifically associated with a reduced incorporation of arachidonate into phospholipids and with an increased conversion of arachidonate into bio-active metabolites.

  19. Role of arachidonic acid cascade in Rhinella arenarum oocyte maturation.

    PubMed

    Ortiz, Maria Eugenia; Arias-Torres, Ana Josefina; Zelarayán, Liliana Isabel

    2015-08-01

    There are no studies that document the production of prostaglandins (PGs) or their role in Rhinella arenarum oocyte maturation. In this study, we analysed the effect of arachidonic acid (AA) and prostaglandins (PGs) on maturation, activation and pronuclear formation in R. arenarum oocytes. Our results demonstrated that AA was capable of inducing maturation in time-dependent and dose-dependent manner. Arachidonic acid-induced maturation was inhibited by indomethacin. PGs from AA hydrolysis, such as prostaglandin F2α (PGF2α) and, to a lesser extent, PGE2, induced meiosis resumption. Oocyte maturation in response to PGF2α was similar to that produced by progesterone (P4). Oocyte response to PGE1 was scarce. Rhinella arenarum oocyte PGF2α-induced maturation showed seasonal variation. From February to June, oocytes presented low sensitivity to PGF2α. In following periods, this response increased until a maximum was reached during October to January, a close temporal correlation with oocyte response to P4 being observed. The effect of PGF2α on maturation was verified by analysing the capacity of oocytes to activate and form pronuclei after being injected with homologous sperm. The cytological analysis of activated oocytes demonstrated the absence of cortical granules in oocytes, suggesting that PGF2α induces germinal vesicle breakdown (GVBD) and meiosis resumption up to metaphase II. In turn, oocytes matured by the action of PGF2α were able to form pronuclei after fertilization in a similar way to oocyte maturated by P4. In microinjection of mature cytoplasm experiments, the transformation of pre-maturation promoting factor (pre-MPF) to MPF was observed when oocytes were treated with PGF2α. In summary, our results illustrated the participation of the AA cascade and its metabolites in maturation, activation and pronuclei formation in R. arenarum. PMID:24964276

  20. Biochemical and subcellular distribution of arachidonic acid in rat myocardium

    SciTech Connect

    Miyazaki, Y.; Gross, R.W.; Sobel, B.E.; Saffitz, J.E. )

    1987-12-01

    Selective release of arachidonic acid from prelabeled phospholipid pools has been observed following exposure of neonatal rat cardiac myocytes to metabolic inhibitors in vitro and has been correlated temporally with the development of irreversible sarcolemmal damage. Hydrolysis of phospholipids with release of arachidonic acid may be an important mechanism in the pathogenesis of sarcolemmal damage induced by ischemia. To elucidate potential subcellular loci of arachidonic acid release in ischemic myocardium, the authors characterized the phospholipid composition of adult rat myocardial sarcolemma and delineated the biochemical and subcellular distribution of radiolabeled arachidonic acid in neonatal rat myocytes incubated with ({sup 3}H)-arachidonic acid for selected intervals. Radioactivity was located almost exclusively in mitochondria and internal cytoplasmic membranes (primarily sarcoplasmic reticulum), which collectively contained 90% of myocyte radioactivity. These results indicate that radiolabeled arachidonic acid released from prelabeled phospholipid pools on exposure of neonatal rat myocytes to oxidative inhibitors is derived from mitochondria and internal cell membranes. The diminutive labeling of the sarcolemma suggests that turnover of arachidonoyl phospholipids is slower in the sarcolemma than in other membranous organelles.

  1. Lipoxygenase-mediated pro-radical effect of melatonin via stimulation of arachidonic acid metabolism

    SciTech Connect

    Radogna, F.; Sestili, P.; Martinelli, C.; Paolillo, M.; Paternoster, L.; Albertini, M.C.; Accorsi, A.; Gualandi, G.; Ghibelli, L.

    2009-07-15

    We have shown that melatonin immediately and transiently stimulates intracellular free radical production on a set of leukocytes, possibly as a consequence of calmodulin binding. We show here that melatonin-induced ROS are produced by lipoxygenase (LOX), since they are prevented by a set of LOX inhibitors, and are accompanied by increase of the 5-LOX product 5-HETE. LOX activation is accompanied by strong liberation of AA; inhibition of Ca{sup 2+}-independent, but not Ca{sup 2+}-dependent, phospholipase A2 (PLA2), prevents both melatonin-induced arachidonic acid and ROS production, whereas LOX inhibition only prevents ROS, indicating that PLA2 is upstream with respect to LOX, as occurs in many signaling pathways. Chlorpromazine, an inhibitor of melatonin-calmodulin interaction, inhibits both ROS and arachidonic acid production, thus possibly placing calmodulin at the origin of a melatonin-induced pro-radical pathway. Interestingly, it is known that Ca{sup 2+}-independent PLA2 binds to calmodulin: our results are compatible with PLA2 being liberated by melatonin from a steady-state calmodulin sequestration, thus initiating an arachidonate signal transduction. These results delineate a novel molecular pathway through which melatonin may participate to the inflammatory response.

  2. Involvement of Nitric Oxide on Calcium Mobilization and Arachidonic Acid Pathway Activation during Platelet Aggregation with different aggregating agonists

    PubMed Central

    Banerjee, Debipriya; Mazumder, Sahana; Kumar Sinha, Asru

    2016-01-01

    Platelet aggregation by different aggregating agonists is essential in the normal blood coagulation process, the excess of which caused acute coronary syndrome (ACS). In all cases, the activation of arachidonic acid by cycloxygenase was needed for the synthesis of thromboxane A2 (TXA2) but the mechanism of arachidonic acid release in platelets remains obscure. Studies were conducted to determine the role of nitric oxide (NO), if any, on the release of arachidonic acid in platelets. The cytosolic Ca2+ was visualized and quantitated by fluorescent spectroscopy by using QUIN-2. NO was measured by methemoglobin method. Arachidonic acid was determined by HPLC. TXA2 was measured as ThromboxaneB2 (TXB2) by ELISA. Treatment of platelets in platelet-rich plasma (PRP) with different aggregating agents resulted in the inhibition of nitric oxide synthase (NOS) which inhibited the production of NO synthesis and increased TXA2 synthesis. Furthermore, the treatment of washed PRP with different platelet aggregating agents resulted in the increase of [Ca2+] in nM ranges. In contrast, the pre-treatment of washed PRP with aspirin increased platelet NO level and inhibited the Ca2+ mobilization and TXA2 synthesis. These results indicated that the aggregation of platelets by different aggregating agonists was caused by the cytosolic Ca2+ mobilization due to the inhibition of NOS. PMID:27127451

  3. Effect of selenium and vitamin E deficiencies on the fate of arachidonic acid in rat isolated lungs

    SciTech Connect

    Uotila, P.; Puustinen, T.

    1985-06-01

    The fate of exogenous /sup 14/C-arachidonic acid (/sup 14/C-AA) was investigated in the isolated lungs of rats fed selenium and vitamin E deficient diet or diets supplemented with selenium and/or vitamin E. When 80 nmol of /sup 14/C-AA was infused into the pulmonary circulation most of the infused /sup 14/C-AA was found in different phospholipid and neutral lipid fractions of the perfused lungs. Only less than ten percent of the infused radioactivity was recovered in the perfusion effluent. The amount of arachidonate metabolites in the perfusion effluent was negligible, and most of the radioactivity in the perfusion effluent consisted of unmetabolized arachidonate. Selenium deficiency had no significant effect on the distribution of /sup 14/C-AA in different lung lipid fractions. However, in the lungs of vitamin E deficient rats the amount of radioactivity was slightly increased in the neutral lipid fraction, which was due to the increased amount of /sup 14/C-AA in the diacylglycerols. The amount of radioactivity was increased especially in the 1,3-diacylglycerols. The amount of radioactivity was increased especially in the 1,3-diacylglycerols. The amount of /sup 14/C-AA in the triacylglycerols and in different phospholipids was not significantly changed. The present study might indicate that selenium deficiency has no significant effect on the fate of exogenous arachidonic acid in isolated rat lungs, and that vitamin E deficiency would slightly increase the amount of arachidonic acid in the diacylglycerols.

  4. Role of Arachidonic Acid in Promoting Hair Growth

    PubMed Central

    Munkhbayar, Semchin; Jang, Sunhyae; Cho, A-Ri; Choi, Soon-Jin; Shin, Chang Yup; Eun, Hee Chul; Kim, Kyu Han

    2016-01-01

    Background Arachidonic acid (AA) is an omega-6 polyunsaturated fatty acid present in all mammalian cell membranes, and involved in the regulation of many cellular processes, including cell survival, angiogenesis, and mitogenesis. The dermal papilla, composed of specialized fibroblasts located in the bulb of the hair follicle, contributes to the control of hair growth and the hair cycle. Objective This study investigated the effect of AA on hair growth by using in vivo and in vitro models. Methods The effect of AA on human dermal papilla cells (hDPCs) and hair shaft elongation was evaluated by MTT assay and hair follicle organ culture, respectively. The expression of various growth and survival factors in hDPCs were investigated by western blot or immunohistochemistry. The ability of AA to induce and prolong anagen phase in C57BL/6 mice was analyzed. Results AA was found to enhance the viability of hDPCs and promote the expression of several factors responsible for hair growth, including fibroblast growth factor-7 (FGF-7) and FGF-10. Western blotting identified the role of AA in the phosphorylation of various transcription factors (ERK, CREB, and AKT) and increased expression of Bcl-2 in hDPCs. In addition, AA significantly promoted hair shaft elongation, with increased proliferation of matrix keratinocytes, during ex vivo hair follicle culture. It was also found to promote hair growth by induction and prolongation of anagen phase in telogen-stage C57BL/6 mice. Conclusion This study concludes that AA plays a role in promoting hair growth by increasing the expression of growth factors in hDPCs and enhancing follicle proliferation and survival. PMID:26848219

  5. Effects of thyroid hormone status on metabolic pathways of arachidonic acid in mice and humans: A targeted metabolomic approach.

    PubMed

    Yao, Xuan; Sa, Rina; Ye, Cheng; Zhang, Duo; Zhang, Shengjie; Xia, Hongfeng; Wang, Yu-cheng; Jiang, Jingjing; Yin, Huiyong; Ying, Hao

    2015-01-01

    Symptoms of cardiovascular diseases are frequently found in patients with hypothyroidism and hyperthyroidism. However, it is unknown whether arachidonic acid metabolites, the potent mediators in cardiovascular system, are involved in cardiovascular disorders caused by hyperthyroidism and hypothyroidism. To answer this question, serum levels of arachidonic acid metabolites in human subjects with hypothyroidism, hyperthyroidism and mice with hypothyroidism or thyroid hormone treatment were determined by a mass spectrometry-based method. Over ten arachidonic acid metabolites belonging to three catalytic pathways: cyclooxygenases, lipoxygenases, and cytochrome P450, were quantified simultaneously and displayed characteristic profiles under different thyroid hormone status. The level of 20-hydroxyeicosatetraenoic acid, a cytochrome P450 metabolite, was positively correlated with thyroid hormone level and possibly contributed to the elevated blood pressured in hyperthyroidism. The increased prostanoid (PG) I2 and decreased PGE2 levels in hypothyroid patients might serve to alleviate atherosclerosis associated with dyslipidemia. The elevated level of thromboxane (TX) A2, as indicated by TXB2, in hyperthyroid patients and mice treated with thyroid hormone might bring about pulmonary hypertension frequently found in hyperthyroid patients. In conclusion, our prospective study revealed that arachidonic acid metabolites were differentially affected by thyroid hormone status. Certain metabolites may be involved in cardiovascular disorders associated with thyroid diseases. PMID:25841349

  6. Mechanism for release of arachidonic acid during guinea pig platelet aggregation: a role for the diacylglycerol lipase inhibitor RHC 80267

    SciTech Connect

    Amin, D.

    1986-01-01

    The mechanism of the release of arachidonic acid from phospholipids after the stimulation of guinea pig platelets with collagen, thrombin and platelet activating factor (PAF) was studied. RHC 80267, a diacylglycerol lipase inhibitor, and indomethacin, a cyclooxygenase inhibitor, were used. Various in vitro assays for enzymes involved in arachidonic acid release and metabolism were conducted. Platelet aggregation and simultaneous release of ADP from platelets were monitored using a Chrono-log Lumiaggregometer. Platelets were labeled with (/sup 14/C)arachidonic acid to facilitate sensitive determination of small changes in platelet phospholipids during platelet aggregation. In the present investigation it is shown that collagen, thrombin and PAF increased phospholipase C activity. It was also discovered that cyclooxygenase products were responsible for further stimulation (a positive feed-back) of phospholipase C activity, while diacylglycerol provided a negative feed-back control over receptor-stimulated phospholipase C activity and inhibited ADP release. The guinea pig platelet is an ideal model to study phospholipase C-diacylglycerol lipase pathway for the release of arachidonic acid from platelet phospholipids because it does not have any phospholipase A/sub 2/ activity. It was observed that cyclooxygenase products were responsible for collagen-induced guinea pig platelet aggregation. Indomethacin completely inhibited collagen-induced platelet aggregation, was less effective against thrombin, and had no effect on PAF-induced platelet aggregation. On the other hand, RHC 80267 was a powerful inhibitor of aggregation and ADP release induced by all three of these potent aggregating agents.

  7. Comparison of the amnestic effects of NMDA receptor antagonist MK-801 and nitric oxide synthase inhibitors: L-NAME and L-NOARG in goldfish.

    PubMed

    Xu, X; Boshoven, W; Lombardo, B; Spranger, J

    1998-08-01

    Investigations indicate that the induction of long-term potentiation (LTP) may be mediated by postsynaptic N-methyl-D-aspartate (NMDA) receptors and that the maintenance of LTP may be initiated by nitric oxide (NO), a retrograde messenger carrying signals backward from the postsynaptic to the presynaptic neuron. The present study compared amnestic effects of dizocilpine maleate (MK-801), an NMDA receptor antagonist, and nitro-L-arginine-methyl-ester (L-NAME) and N-nitro-L-arginine (L-NOARG), nitric oxide (NO) inhibitors, in goldfish, using active-avoidance conditioning as the learning paradigm. The results showed that MK-801 and NO inhibitors produced anterograde amnesia at doses that did not impair performance processes necessary for learning to occur. Furthermore, MK-801 did not produce retrograde amnesia, whereas L-NAME did, suggesting that MK-801 impaired learning whereas NO inhibitors impaired memory consolidation and possibly also learning.

  8. Arachidonic acid assimilation by thrombocytes from white carneau pigeons

    SciTech Connect

    Saxon, D.J.; Blankenship, T.

    1986-03-01

    The metabolism of arachidonic acid was investigated using thrombocyte-enriched-plasma from RBWC and WC-II white carneau pigeons, which differ genetically in their susceptibility to atherosclerosis. Thrombocytes were incubated at 42 C with (/sup 14/C) arachidonate in Puck's solution. After a 1 hour labeling period the WC-II cells had taken up 69% and RBWC 77% of the (/sup 14/C)arachidonate from the medium. When 8,11,14-eicosatrienoic acid or 5,8,11,14,17-eicosapentaenoic acid were added to incubation media the (/sup 14/C) uptake was reduced in each type cell, with WC-II exhibiting the greatest effect. Release of (/sup 14/C)molecules from cells labeled with (/sup 14/)Carachidonate was studied using calcium ionophore and indomethacin. Indomethacin inhibited (/sup 14/C) molecule release similarly in both RBWC and WC-II cells. Calcium ionophore was twice as effective in stimulating (/sup 14/C)molecule release from WC-II than RBWC cells. Therefore, the WE-II cells (from pigeons greater in susceptibility to atherosclerosis) are more sensitive to calcium ionophore than the REWC cells.

  9. NO system dependence of atropine-induced mydriasis and L-NAME- and L-arginine-induced miosis: Reversal by the pentadecapeptide BPC 157 in rats and guinea pigs.

    PubMed

    Kokot, Antonio; Zlatar, Mirna; Stupnisek, Mirjana; Drmic, Domagoj; Radic, Radivoje; Vcev, Aleksandar; Seiwerth, Sven; Sikiric, Predrag

    2016-01-15

    We revealed an immediate and hours-lasting particular NO-specific parallel miotic effect of L-NAME and L-arginine in rats and guinea pigs and a stable gastric pentadecapeptide BPC 157 157-particular effect vs. that of atropine-induced mydriasis while examining the NO system role in the normal pupils responses and pupils with atropine-induced mydriasis. We also assessed the responses to BPC 157 and its possible modulation of the changes caused by L-NAME/L-arginine and atropine. We administered locally (two drops/eye) or systemically (intraperitoneally/kg) [BPC 157 (0.4µg/eye; 10µg, 10ng, 10pg/kg), L-NAME (0.1mg/eye; 5mg/kg), and L-arginine (2mg/eye; 100mg/kg) alone and combined] at 3min prior to assessment (normal pupils) or alternatively at maximal 1% atropine-induced mydriasis (30min after two drops were administered to each eye). L-NAME/L-arginine. Normal pupil. L-NAME-miosis and L-arginine-miosis shortened and attenuated each other's responses when combined (L-NAME+L-arginine) (except with guinea pigs treated locally) and were thereby NO-specific. Atropine-pupil. Both L-NAME and L-arginine counteracted atropine-induced mydriasis. With few exceptions, the atropine+L-NAME+L-arginine-animals showed a consistent shift toward the left. BPC 157. Normal pupil. Always, BPC 157 alone (both species; locally; systemically; all regimens) did not affect normal pupils. Despite specific exceptions, BPC 157 distinctively affects L-arginine-miosis (prolongation) and L-NAME-miosis (shortening). When L-arginine and L-NAME were combined (L-NAME+L-arginine+BPC 157), the effect was less pronounced. Atropine-pupil. BPC 157 alone counteracted atropine-induced mydriasis. With few exceptions (when administered with L-NAME or L-arginine or L-NAME+L-arginine), BPC 157 augments their counteracting effects. Thus, along with its l-NAME/L-arginine effects, BPC 157 participates in ocular control, potentially via NO-mediated and cholinergic mechanisms.

  10. NO system dependence of atropine-induced mydriasis and L-NAME- and L-arginine-induced miosis: Reversal by the pentadecapeptide BPC 157 in rats and guinea pigs.

    PubMed

    Kokot, Antonio; Zlatar, Mirna; Stupnisek, Mirjana; Drmic, Domagoj; Radic, Radivoje; Vcev, Aleksandar; Seiwerth, Sven; Sikiric, Predrag

    2016-01-15

    We revealed an immediate and hours-lasting particular NO-specific parallel miotic effect of L-NAME and L-arginine in rats and guinea pigs and a stable gastric pentadecapeptide BPC 157 157-particular effect vs. that of atropine-induced mydriasis while examining the NO system role in the normal pupils responses and pupils with atropine-induced mydriasis. We also assessed the responses to BPC 157 and its possible modulation of the changes caused by L-NAME/L-arginine and atropine. We administered locally (two drops/eye) or systemically (intraperitoneally/kg) [BPC 157 (0.4µg/eye; 10µg, 10ng, 10pg/kg), L-NAME (0.1mg/eye; 5mg/kg), and L-arginine (2mg/eye; 100mg/kg) alone and combined] at 3min prior to assessment (normal pupils) or alternatively at maximal 1% atropine-induced mydriasis (30min after two drops were administered to each eye). L-NAME/L-arginine. Normal pupil. L-NAME-miosis and L-arginine-miosis shortened and attenuated each other's responses when combined (L-NAME+L-arginine) (except with guinea pigs treated locally) and were thereby NO-specific. Atropine-pupil. Both L-NAME and L-arginine counteracted atropine-induced mydriasis. With few exceptions, the atropine+L-NAME+L-arginine-animals showed a consistent shift toward the left. BPC 157. Normal pupil. Always, BPC 157 alone (both species; locally; systemically; all regimens) did not affect normal pupils. Despite specific exceptions, BPC 157 distinctively affects L-arginine-miosis (prolongation) and L-NAME-miosis (shortening). When L-arginine and L-NAME were combined (L-NAME+L-arginine+BPC 157), the effect was less pronounced. Atropine-pupil. BPC 157 alone counteracted atropine-induced mydriasis. With few exceptions (when administered with L-NAME or L-arginine or L-NAME+L-arginine), BPC 157 augments their counteracting effects. Thus, along with its l-NAME/L-arginine effects, BPC 157 participates in ocular control, potentially via NO-mediated and cholinergic mechanisms. PMID:26698393

  11. Cytosolic phospholipase A2 is coupled to hormonally regulated release of arachidonic acid.

    PubMed Central

    Lin, L L; Lin, A Y; Knopf, J L

    1992-01-01

    Cytosolic phospholipase A2 (cPLA2) binds to natural membrane vesicles in a Ca(2+)-dependent fashion, resulting in the selective release of arachidonic acid, thus implicating cPLA2 in the hormonally regulated production of eicosanoids. Here we report that the treatment of Chinese hamster ovary (CHO) cells overexpressing cPLA2 with ATP or thrombin resulted in an increased release of arachidonic acid as compared with parental CHO cells, demonstrating the hormonal coupling of cPLA2. In contrast, CHO cells overexpressing a secreted form of mammalian PLA2 (sPLA2-II) failed to show any increased hormonal responsiveness. Interestingly, we have noted that the activation of cPLA2 with a wide variety of agents stimulates the phosphorylation of cPLA2 on serine residues. Pretreatment of cells with staurosporin blocked the ATP-mediated phosphorylation of cPLA2 and strongly inhibited the activation of the enzyme. Increased cPLA2 activity was also observed in lysates prepared from ATP-treated cells and was sensitive to phosphatase treatment. These results suggest that in addition to Ca2+, the phosphorylation of cPLA2 plays an important role in the agonist-induced activation of cPLA2. Images PMID:1631101

  12. The effect of ozone exposure on rat alveolar macrophage arachidonic acid metabolism

    SciTech Connect

    Madden, M.C.; Eling, T.E.; Dailey, L.A.; Friedman, M. )

    1991-01-01

    Rat alveolar macrophages were prelabeled with {sup 3}H-arachidonic acid ({sup 3}H-AA) and exposed to air or O3 (0.1-1.0 ppm) in vitro for 2 h. Alveolar macrophages released 3.6-fold more tritium at the 1.0 ppm exposure concentration compared with air-exposed macrophages. A significantly increased production of several {sup 3}H-AA metabolites, including 6-keto-PGF1 alpha, thromboxane B2, 12-hydroxy-5,8,10-heptadecatrienoic acid, prostaglandins E2 and D2, leukotrienes B4 and D4, and 15-hydroxyeicosatetraenoic acid was formed by macrophages exposed to 1.0 ppm O3 compared with air-exposed macrophages as determined by high performance liquid chromatography (HPLC) analysis. O3 exposure did not alter macrophage {sup 3}H-AA metabolism in response to calcium ionophore A23187. The largest tritiated peak observed in the HPLC chromatograms of O{sub 3}-exposed cells was a polar complex of products that contained various phospholipids and neutral lipids (including diacylglycerol) and possibly degradation products of {sup 3}H-AA and some of its metabolites. These changes in macrophage arachidonic acid metabolism may play an important role in the lung response to O{sub 3} exposure in vivo.

  13. Modulation of arachidonic acid metabolism by Rous sarcoma virus

    SciTech Connect

    Barker, K.; Aderem, A.; Hanafusa, H. )

    1989-07-01

    Arachidonic acid (C{sub 20:4}) metabolites were released constitutively from wild-type Rous sarcoma virus-transformed chicken embryo fibroblasts (CEF). {sup 3}H-labeled C{sub 20:4} and its metabolites were released from unstimulated and uninfected CEF only in response to stimuli such as serum, phorbol ester, or the calcium ionophore A23187. High-pressure liquid chromatography analysis showed that the radioactivity released from ({sup 3}H)arachidonate-labeled transformed cells was contained in free arachidonate and in the cyclooxygenase products prostaglandin E{sub 2} and prostaglandin F{sub 2} alpha; no lipoxygenase products were identified. The release of C{sub 20:4} and its metabolites from CEF infected with pp60{sup src} deletion mutants was correlated with serum-independent DNA synthesis and with the expression of the mRNA for 9E3, a gene expressed in Rous sarcoma virus-transformed cells which has homology with several mitogenic and inflammatory peptides. {sup 3}H-labeled C{sub 20:4} release was not correlated with p36 phosphorylation, which argues against a role for this protein as a phospholipase A{sub 2} inhibitor. CEF infected with other oncogenic viruses encoding a tyrosine kinase also released C{sub 20:4}, as did CEF infected with viruses that contained mos and ras; however, infection with a crk-containing virus did not result in stimulation of {sup 3}H-labeled C{sub 20:4} release, suggesting that utilization of this signaling pathway is specific for particular transformation stimuli.

  14. Fungal arachidonic acid-rich oil: research, development and industrialization.

    PubMed

    Ji, Xiao-Jun; Ren, Lu-Jing; Nie, Zhi-Kui; Huang, He; Ouyang, Ping-Kai

    2014-09-01

    Fungal arachidonic acid (ARA)-rich oil is an important microbial oil that affects diverse physiological processes that impact normal health and chronic disease. In this article, the historic developments and technological achievements in fungal ARA-rich oil production in the past several years are reviewed. The biochemistry of ARA, ARA-rich oil synthesis and the accumulation mechanism are first introduced. Subsequently, the fermentation and downstream technologies are summarized. Furthermore, progress in the industrial production of ARA-rich oil is discussed. Finally, guidelines for future studies of fungal ARA-rich oil production are proposed in light of the current progress, challenges and trends in the field.

  15. Acute doxorubicin cardiotoxicity alters cardiac cytochrome P450 expression and arachidonic acid metabolism in rats

    SciTech Connect

    Zordoky, Beshay N.M.; Anwar-Mohamed, Anwar; Aboutabl, Mona E.

    2010-01-01

    Doxorubicin (DOX) is a potent anti-neoplastic antibiotic used to treat a variety of malignancies; however, its use is limited by dose-dependent cardiotoxicity. Moreover, there is a strong correlation between cytochrome P450 (CYP)-mediated arachidonic acid metabolites and the pathogenesis of many cardiovascular diseases. Therefore, in the current study, we have investigated the effect of acute DOX toxicity on the expression of several CYP enzymes and their associated arachidonic acid metabolites in the heart of male Sprague-Dawley rats. Acute DOX toxicity was induced by a single intraperitoneal injection of 15 mg/kg of the drug. Our results showed that DOX treatment for 24 h caused a significant induction of CYP1A1, CYP1B1, CYP2C11, CYP2J3, CYP4A1, CYP4A3, CYP4F1, CYP4F4, and EPHX2 gene expression in the heart of DOX-treated rats as compared to the control. Similarly, there was a significant induction of CYP1A1, CYP1B1, CYP2C11, CYP2J3, CYP4A, and sEH proteins after 24 h of DOX administration. In the heart microsomes, acute DOX toxicity significantly increased the formation of 20-HETE which is consistent with the induction of the major CYP omega-hydroxylases: CYP4A1, CYP4A3, CYP4F1, and CYP4F4. On the other hand, the formation of 5,6-, 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acids (EETs) was significantly reduced, whereas the formation of their corresponding dihydroxyeicosatrienoic acids was significantly increased. The decrease in the cardioprotective EETs can be attributed to the increase of sEH activity parallel to the induction of the EPHX2 gene expression in the heart of DOX-treated rats. In conclusion, acute DOX toxicity alters the expression of several CYP and sEH enzymes with a consequent alteration in arachidonic acid metabolism. These results may represent a novel mechanism by which this drug causes progressive cardiotoxicity.

  16. Measurement of the incorporation of orally administered arachidonic acid into tissue lipids

    SciTech Connect

    Kulmacz, R.J.; Sivarajan, M.; Lands, W.E.

    1986-01-01

    The applicability of a stable isotope method to monitor the mixing of dietary arachidonic acid with endogenous arachidonic acid in tissue lipids was evaluated. Rats were fed octadeuterated arachidonic acid during a 20-day period, and the entry of the dietary acid into lipid esters of various tissues was examined by gas chromatography-mass spectrometric (GC-MS) analysis of their fatty acids. The rats were maintained on a fat-free diet from weaning until 63 days old to enhance the ratio of the dietary acid to endogenous arachidonate. Three separate forms of eicosatetraenoic acid in the tissue lipids could be distinguished by GC-MS: octadeuterated arachidonic acid (recent dietary origin), unlabeled arachidonic acid (maternal origin) and unlabeled 4,7,10,13-eicosatetraenoic acid (originating from palmitoleic acid). The total eicosatetraenoic acid in the tissue lipids contained about 90% arachidonate from recent dietary origin in lung, kidney, heart and fat, 70% in muscle and liver and 27% in brain. The n-7 isomer of eicosatetraenoic acid was estimated to make up 6% or less of the total eicosatetraenoic acid in lung, kidney, brain, muscle and heart tissue lipids, but it comprised around 15% of the total eicosatetraenoic acid in liver. The unlabeled arachidonic acid of maternal origin thus comprised only about 10% of the eicosatetraenoic acid in all tissues examined except muscle and brain, where it was 24% and 70% of the eicosatetraenoic acid, respectively.

  17. Phosphate limitation promotes unsaturated fatty acids and arachidonic acid biosynthesis by microalgae Porphyridium purpureum.

    PubMed

    Su, Gaomin; Jiao, Kailin; Li, Zheng; Guo, Xiaoyi; Chang, Jingyu; Ndikubwimana, Theoneste; Sun, Yong; Zeng, Xianhai; Lu, Yinghua; Lin, Lu

    2016-07-01

    Polyunsaturated fatty acids (PUFAs) are highly appreciated on their nutritive value for human health and aquaculture. P. purpureum, one of the red microalgae acknowledged as a promising accumulator of ARA, was chosen as the target algae in the present research. Effects of sodium bicarbonate (0.04-1.2 g/L), temperature (25, 30 and 33 °C) and phosphate (0.00-0.14 g/L) on biomass yield, total fatty acids (TFA) and arachidonic acid (ARA) accumulation were investigated systemically. NaHCO3 dose of 0.8 g/L and moderate temperature of 30 °C were preferred. In addition, TFA and ARA production were significantly enhanced by an appropriate concentration of phosphate, and the highest TFA yield of 666.38 mg/L and ARA yield of 159.74 mg/L were obtained at a phosphate concentration of 0.035 g/L. Interestingly, with phosphate concentration continuing to fall, UFA/TFA and ARA/EPA ratios were increased accordingly, suggesting that phosphate limitation promoted unsaturated fatty acids and arachidonic acid biosynthesis. Low concentration of phosphate may be favored to increase the enzymatic activities of ∆6-desaturase, which played a key role in catalyzing the conversion of C16:0 to C18:2, and thus the selectivity of UFA increased. Meanwhile, the increase of ARA selectivity could be attributed to ω6 pathway promotion and ∆17-desaturase activity inhibition with phosphate limitation. Phosphate limitation strategy enhanced unsaturated fatty acids and ARA biosynthesis in P. purpureum, and can be applied in commercial scale manufacturing and commercialization of ARA. PMID:27004948

  18. Phosphate limitation promotes unsaturated fatty acids and arachidonic acid biosynthesis by microalgae Porphyridium purpureum.

    PubMed

    Su, Gaomin; Jiao, Kailin; Li, Zheng; Guo, Xiaoyi; Chang, Jingyu; Ndikubwimana, Theoneste; Sun, Yong; Zeng, Xianhai; Lu, Yinghua; Lin, Lu

    2016-07-01

    Polyunsaturated fatty acids (PUFAs) are highly appreciated on their nutritive value for human health and aquaculture. P. purpureum, one of the red microalgae acknowledged as a promising accumulator of ARA, was chosen as the target algae in the present research. Effects of sodium bicarbonate (0.04-1.2 g/L), temperature (25, 30 and 33 °C) and phosphate (0.00-0.14 g/L) on biomass yield, total fatty acids (TFA) and arachidonic acid (ARA) accumulation were investigated systemically. NaHCO3 dose of 0.8 g/L and moderate temperature of 30 °C were preferred. In addition, TFA and ARA production were significantly enhanced by an appropriate concentration of phosphate, and the highest TFA yield of 666.38 mg/L and ARA yield of 159.74 mg/L were obtained at a phosphate concentration of 0.035 g/L. Interestingly, with phosphate concentration continuing to fall, UFA/TFA and ARA/EPA ratios were increased accordingly, suggesting that phosphate limitation promoted unsaturated fatty acids and arachidonic acid biosynthesis. Low concentration of phosphate may be favored to increase the enzymatic activities of ∆6-desaturase, which played a key role in catalyzing the conversion of C16:0 to C18:2, and thus the selectivity of UFA increased. Meanwhile, the increase of ARA selectivity could be attributed to ω6 pathway promotion and ∆17-desaturase activity inhibition with phosphate limitation. Phosphate limitation strategy enhanced unsaturated fatty acids and ARA biosynthesis in P. purpureum, and can be applied in commercial scale manufacturing and commercialization of ARA.

  19. Altered Arachidonate Distribution in Macrophages from Caveolin-1 Null Mice Leading to Reduced Eicosanoid Synthesis*

    PubMed Central

    Astudillo, Alma M.; Pérez-Chacón, Gema; Meana, Clara; Balgoma, David; Pol, Albert; del Pozo, Miguel A.; Balboa, María A.; Balsinde, Jesús

    2011-01-01

    In this work we have studied the effect of caveolin-1 deficiency on the mechanisms that regulate free arachidonic acid (AA) availability. The results presented here demonstrate that macrophages from caveolin-1-deficient mice exhibit elevated fatty acid incorporation and remodeling and a constitutively increased CoA-independent transacylase activity. Mass spectrometry-based lipidomic analyses reveal stable alterations in the profile of AA distribution among phospholipids, manifested by reduced levels of AA in choline glycerophospholipids but elevated levels in ethanolamine glycerophospholipids and phosphatidylinositol. Furthermore, macrophages from caveolin-1 null mice show decreased AA mobilization and prostaglandin E2 and LTB4 production upon cell stimulation. Collectively, these results provide insight into the role of caveolin-1 in AA homeostasis and suggest an important role for this protein in the eicosanoid biosynthetic response. PMID:21852231

  20. Liquid human milk fortifier significantly improves docosahexaenoic and arachidonic acid status in preterm infants.

    PubMed

    Berseth, C L; Harris, C L; Wampler, J L; Hoffman, D R; Diersen-Schade, D A

    2014-09-01

    We report the fatty acid composition of mother׳s own human milk from one of the largest US cohorts of lactating mothers of preterm infants. Milk fatty acid data were used as a proxy for intake at enrollment in infants (n=150) who received human milk with a powder human milk fortifier (HMF; Control) or liquid HMF [LHMF; provided additional 12mg docosahexaenoic acid (DHA), 20mg arachidonic acid (ARA)/100mL human milk]. Mothers provided milk samples (n=129) and reported maternal DHA consumption (n=128). Infant blood samples were drawn at study completion (Study Day 28). Human milk and infant PPL fatty acids were analyzed using capillary column gas chromatography. DHA and ARA were within ranges previously published for US term and preterm human milk. Compared to Control HMF (providing no DHA or ARA), human milk fortified with LHMF significantly increased infant PPL DHA and ARA and improved preterm infant DHA and ARA status.

  1. Potential, pH, and arachidonate gate hydrogen ion currents in human neutrophils.

    PubMed Central

    DeCoursey, T E; Cherny, V V

    1993-01-01

    Indirect evidence indicates that a proton-selective conductance is activated during the respiratory burst in neutrophils. A voltage- and time-dependent H(+)-selective conductance, gH, in human neutrophils is demonstrated here directly by the whole-cell patch-clamp technique. The gH is extremely low at large negative potentials, increases slowly upon membrane depolarization, and does not inactivate. It is enhanced at high external pH or low internal pH and is inhibited by Cd2+ and Zn2+. Arachidonic acid, which plays a pivotal role in inflammatory reactions, amplifies the gH. The properties of the gH described here are compatible with its activation during the respiratory burst in stimulated neutrophils, in which it may facilitate sustained superoxide anion release by dissipating metabolically generated acid. PMID:7506066

  2. A nitric oxide synthase inhibitor (L-NAME) attenuates abstinence-induced withdrawal from both cocaine and a cannabinoid agonist (WIN 55212-2) in Planaria.

    PubMed

    Rawls, Scott M; Rodriguez, Tonatiu; Baron, David A; Raffa, Robert B

    2006-07-12

    We previously reported that planarians (Dugesia dorotocephala) that have been exposed to cocaine for 1 h undergo abstinence-induced withdrawal when placed into cocaine-free, but not cocaine-containing, water. We now report that planarians also display dose-related abstinence-induced withdrawal following exposure to the synthetic cannabinoid agonist WIN 55212-2, but not its inactive enantiomer (WIN 55212-3). The withdrawal from WIN 55212-2 was manifested as a significant (P < 0.05) decrease in the rate of planarian spontaneous locomotor activity over a 5-min observation period, using a recently designed metric (pLMV). We also report that withdrawal from cocaine (80 microM) or WIN 55212-2 (10 microM) was attenuated by the selective inhibitor of nitric oxide synthesis L-NAME (L-nitro-arginine methyl ester), which had no effect of its own on pLMV. These results suggest a common NO-dependent pathway of withdrawal from cocaine and WIN 55212-2 in Planaria.

  3. Effects of exogenous arachidonic, eicosapentaenoic, and docosahexaenoic acids on the generation of 5-lipoxygenase pathway products by ionophore-activated human neutrophils.

    PubMed Central

    Lee, T H; Mencia-Huerta, J M; Shih, C; Corey, E J; Lewis, R A; Austen, K F

    1984-01-01

    concentrations in the presence of EPA was not due to a change in the kinetic appearance of LTB4 or to an increase in conversion to its omega-oxidation metabolites. DCHA was metabolized to 7-hydroxy-DCHA, did not stimulate metabolism of membrane-derived arachidonic acid, did not appreciably inhibit LTB4 formation, and was not a substrate for leukotriene formation. Incremental doses of exogenous arachidonic acid resulted in increased production of 5-hydroxyeicosatetraenoic acid and 6-trans-LTB4 by ionophore-activated, [14C]arachidonic acid-labeled neutrophils without any change in LTB4 production. 5-hydroxyeicosapentaenoic acid and 7-hydroxy DCHA were inactive as chemotactic factors whereas 5-hydroxyeicosatetraenoic acid exhibited 2% of the potency of LBT4. Thus, exogenous DCHA does not appreciably interfere with the metabolism of membrane-derived arachidonic acid by ionophore-activated, [14C]arachidonic acid-labeled neutrophils and is converted only to a monohydroxy derivative. In contrast, exogenous EPA attenuates the generation of LTB4 and is converted to LTB5, which is a weak and partial agonist as compared with LTB4. Images PMID:6096400

  4. Inhibiting the neuronal isoform of nitric oxide synthase has similar effects on the compensatory choroidal and axial responses to myopic defocus in chicks as does the non-specific inhibitor L-NAME.

    PubMed

    Nickla, Debora L; Damyanova, Petya; Lytle, Grace

    2009-06-01

    In birds, the choroid plays a role in the visual regulation of eye growth, thickening in response to myopic defocus, and thinning in response to hyperopic defocus, in both cases moving the retina towards the image plane. This response is rapid, occurring within hours of the defocus stimulus. These changes are consistently associated with slower changes in the sclera, that result in the appropriate changes in axial elongation, decreasing growth in response to myopic defocus and increasing it in response to hyperopic defocus. The molecular mechanisms underlying the scleral response involve changes in the synthesis of extracellular matrix molecules, however, those underlying the changes in choroidal thickness are not known. However, evidence suggests that it may involve the gaseous signal molecule nitric oxide, as nitric oxide is a potent smooth muscle relaxant, and injections of the non-specific nitric oxide synthase inhibitor L-NAME transiently inhibits the thickening response. Interestingly, it also dis-inhibits ocular growth, in accordance with a mechanistic link between the two responses. If nitric oxide is part of the signal cascade underlying the visual regulation of eye growth, it would be important to ascertain the source of the molecule. As a first step towards doing so, we used various more specific NOS inhibitors and studied their effects on the choroidal and growth responses. Birds (7-12 days old) were fitted with +10 D lenses on one eye. On that day, single intravitreal injections (30 microl) of the following inhibitors were used: nNOS inhibitor N(omega)-propyl-L-arginine (n=12), iNOS inhibitor L-NIL (n=16), eNOS/iNOS inhibitor L-NIO (n=15), non-specific inhibitor L-NMMA (n=30) or physiological saline (n=18). Ocular dimensions were measured using high-frequency A-scan ultrasonography at the start of the experiment, and at 7, 24 and 48 h after. We found that the nNOS inhibitor N(omega)-propyl-L-arginine had the same inhibitory effects on the choroidal

  5. Arachidonic acid metabolites do not mediate toluene diisocyanate-induced airway hyperresponsiveness in guinea pigs

    SciTech Connect

    Gordon, T.; Thompson, J.E.; Sheppard, D.

    1988-05-01

    Arachidonic acid metabolites have previously been demonstrated to mediate the airway hyperresponsiveness observed in guinea pigs and dogs after exposure to ozone. Guinea pigs were treated with indomethacin (a cyclooxygenase inhibitor), U-60,257 (piriprost, a 5-lipoxygenase inhibitor), or BW775c (a lipoxygenase and cyclooxygenase inhibitor) and exposed to air or 3 ppm TDI. Airway responsiveness to acetylcholine aerosol was examined 2 h after exposure. In control animals, the provocative concentration of acetylcholine which caused a 200% increase in pulmonary resistance over baseline (PC200) was significantly less (p less than 0.05) after exposure to TDI (8.6 +/- 2.0 mg/ml, geometric mean + geometric SE, n = 10) than after exposure to air (23.9 + 2.5 mg/ml, n = 14). The airway responsiveness to acetylcholine in animals treated with indomethacin or piriprost and exposed to TDI was not different from that of control animals exposed to TDI. Treatment with BW755c enhanced the airway hyperresponsiveness observed in animals exposed to TDI without altering the PC200 of animals exposed to air. The PC200 of animals treated with BW755c and exposed to TDI (2.3 + 0.8 mg/ml, n = 8) was significantly lower than the PC200 of control animals exposed to TDI (p less than 0.025). These results suggest that products of arachidonic acid metabolism are not responsible for TDI-induced airway hyperresponsiveness in guinea pigs. BW755c, however, appears to potentiate the TDI-induced airway hyperresponsiveness to acetylcholine by an as yet unidentified mechanism.

  6. [Elicitor activity of chitosan and arachidonic acid: their similarity and distinction].

    PubMed

    Vasiukova, N I; Gerasimova, N G; Chalenko, G I; Ozeretskovskaia, O L

    2012-01-01

    Two elicitors-chitosan and arachidonic acid-induced the same defense responses in potatoes, stimulating the processes of wound reparation and inducing the formation of phytoalexins, inhibitors of proteinase, and active forms of oxygen. However, chitosan induced the defense potential of plant tissues at concentrations higher than those of arachidonic acid. The protective action of chitosan was defined by two parameters, i.e., the ability to induce the immune responses in plant tissues and to exhibit a toxic effect on the pathogen development, causing late blight and seedling blight, whereas the elicitor effect of arachidonic acid depended on its ability to induce the defense potential of plant tissues only.

  7. Astrocyte arachidonate and palmitate uptake and metabolism is differentially modulated by dibutyryl-cAMP treatment.

    PubMed

    Seeger, D R; Murphy, C C; Murphy, E J

    2016-07-01

    Astrocytes play a vital role in brain lipid metabolism; however the impact of the phenotypic shift in astrocytes to a reactive state on arachidonic acid metabolism is unknown. Therefore, we determined the impact of dibutyryl-cAMP (dBcAMP) treatment on radiolabeled arachidonic acid ([1-(14)C]20:4n-6) and palmitic acid ([1-(14)C]16:0) uptake and metabolism in primary cultured murine cortical astrocytes. In dBcAMP treated astrocytes, total [1-(14)C]20:4n-6 uptake was increased 1.9-fold compared to control, while total [1-(14)C]16:0 uptake was unaffected. Gene expression of long-chain acyl-CoA synthetases (Acsl), acyl-CoA hydrolase (Acot7), fatty acid binding protein(s) (Fabp) and alpha-synuclein (Snca) were determined using qRT-PCR. dBcAMP treatment increased expression of Acsl3 (4.8-fold) and Acsl4 (1.3-fold), which preferentially use [1-(14)C]20:4n-6 and are highly expressed in astrocytes, consistent with the increase in [1-(14)C]20:4n-6 uptake. However, expression of Fabp5 and Fabp7 were significantly reduced by 25% and 45%, respectively. Acot7 (20%) was also reduced, suggesting dBcAMP treatment favors acyl-CoA formation. dBcAMP treatment enhanced [1-(14)C]20:4n-6 (2.2-fold) and [1-(14)C]16:0 (1.6-fold) esterification into total phospholipids, but the greater esterification of [1-(14)C]20:4n-6 is consistent with the observed uptake through increased Acsl, but not Fabp expression. Although total [1-(14)C]16:0 uptake was not affected, there was a dramatic decrease in [1-(14)C]16:0 in the free fatty acid pool as esterification into the phospholipid pool was increased, which is consistent with the increase in Acsl3 and Acsl4 expression. In summary, our data demonstrates that dBcAMP treatment increases [1-(14)C]20:4n-6 uptake in astrocytes and this increase appears to be due to increased expression of Acsl3 and Acsl4 coupled with a reduction in Acot7 expression. PMID:27255639

  8. In vitro release of arachidonic acid metabolites, glutathione peroxidase, and oxygen-free radicals from platelets of asthmatic patients with and without aspirin intolerance.

    PubMed Central

    Plaza, V.; Prat, J.; Rosellò, J.; Ballester, E.; Ramis, I.; Mullol, J.; Gelpí, E.; Vives-Corrons, J. L.; Picado, C.

    1995-01-01

    BACKGROUND--An abnormal platelet release of oxygen-free radicals has been described in acetylsalicylic acid (aspirin)-induced asthma, a finding which might suggest the existence of an intrinsic, specific platelet abnormality of arachidonic acid metabolism in these patients. The objective of this study was to evaluate platelet arachidonic acid metabolism in asthmatic patients with or without intolerance to aspirin. METHODS--Thirty subjects distributed into three groups were studied: group 1, 10 healthy subjects; group 2, 10 asthmatic patients with aspirin tolerance; and group 3, 10 aspirin-intolerant asthmatics. Platelets were isolated from blood, preincubated with 3H-arachidonic acid for 30 minutes and then incubated for 10 minutes with platelet activating factor (PAF) and aspirin. Cyclo-oxygenase (thromboxane, PGE2, PGF2 alpha, and HHT) and lipoxygenase (12-HETE) arachidonic acid metabolites were measured by high pressure liquid chromatography. Release of oxygen free radicals after incubation with PAF and aspirin was measured by chemiluminescence. Platelet levels of glutathione peroxidase (GSH-Px) were also measured using spectrophotometry. RESULTS--Platelets from aspirin-intolerant asthmatic patients produced higher quantities of arachidonic acid metabolites than the control group at baseline conditions. This increase was significant only for lipoxygenase products. No differences were found amongst the three groups in the response of arachidonic acid metabolism to PAF and aspirin. Incubation with aspirin but not with PAF caused an increase in oxygen-free radical production in aspirin-intolerant patients whereas in aspirin-tolerant patients PAF, rather than aspirin, was the more potent stimulus for oxygen-free radical production. No differences in GSH-Px levels were found amongst the three groups. CONCLUSIONS--These results suggest that the platelet lipoxygenase pathway is activated in aspirin-intolerant patients and that the production of oxygen-free radicals may

  9. Ca/sup 2 +/-dependent and Ca/sup 2 +/-independent pathways for release of arachidonic acid from phosphatidylinositol in endothelial cells

    SciTech Connect

    Martin, T.W.; Wysolmerski, R.B.

    1987-09-25

    The pathways for degradation of phosphatidylinositol (PI) were investigated in sonicated suspensions prepared from confluent cultures of bovine pulmonary artery endothelial cells. The time courses of formation of /sup 3/H-labeled and /sup 14/C-labeled metabolites of phosphatidyl-(/sup 3/H)inositol ((/sup 3/H)Ins-PI) and 1-stearoyl-2-(/sup 14/C) arachidonoyl-PI were determined at 37/sup 0/C and pH 7.5 in the presence of 2 mM EDTA with or without a 2 mM excess of Ca/sup 2 +/. The rates of formation of lysophosphatidyl-(/sup 3/H)inositol ((/sup 3/H)Ins-lyso-PI) and 1-lyso-2-(/sup 14/C) arachidonoyl-PI were similar in the presence and absence of Ca/sup 2 +/, and the absolute amounts of the two radiolabeled lyso-PI products formed were nearly identical. This indicated that lyso-PI was formed by phospholipase A1, and phospholipase A2 was not measurable. In the presence of EDTA, (/sup 14/C)arachidonic acid release from 1-stearoyl-2-(/sup 14/C)arachidonoyl-PI paralleled release of glycerophospho-(/sup 3/H)inositol ((/sup 3/H)GPI) from (/sup 3/H)Ins-PI. Formation of (/sup 3/H)GPI was inhibited by treatment with the specific sulfhydryl reagent, 2,2'-dithiodipyridine, and this was accompanied by an increase in (/sup 3/H)Ins-lyso-PI. In the presence of Ca/sup 2 +/, (/sup 14/C) arachidonic acid release from 1-stearoyl-2-(/sup 14/C)arachidonoyl-PI was increased 2-fold and was associated with Ca/sup 2 +/-dependent phospholipase C activity. Under these conditions, (/sup 3/H)inositol monophosphate production exceeded formation of (/sup 14/C)arachidonic acid-labeled phospholipase C products, diacylglycerol plus monoacylglycerol, by an amount that was equal to the amount of (/sup 14/C)arachidonic acid formed in excess of (/sup 3/H)GPI. Low concentrations of phenylmethanesulfonyl fluoride (15-125 microM) inhibited Ca/sup 2 +/-dependent (/sup 14/C)arachidonic acid release, and the decrease in (/sup 14/C) arachidonic acid formed was matched by an equivalent increase in /sup 14/C label

  10. The Essentiality of Arachidonic Acid in Infant Development

    PubMed Central

    Hadley, Kevin B.; Ryan, Alan S.; Forsyth, Stewart; Gautier, Sheila; Salem, Norman

    2016-01-01

    Arachidonic acid (ARA, 20:4n-6) is an n-6 polyunsaturated 20-carbon fatty acid formed by the biosynthesis from linoleic acid (LA, 18:2n-6). This review considers the essential role that ARA plays in infant development. ARA is always present in human milk at a relatively fixed level and is accumulated in tissues throughout the body where it serves several important functions. Without the provision of preformed ARA in human milk or infant formula the growing infant cannot maintain ARA levels from synthetic pathways alone that are sufficient to meet metabolic demand. During late infancy and early childhood the amount of dietary ARA provided by solid foods is low. ARA serves as a precursor to leukotrienes, prostaglandins, and thromboxanes, collectively known as eicosanoids which are important for immunity and immune response. There is strong evidence based on animal and human studies that ARA is critical for infant growth, brain development, and health. These studies also demonstrate the importance of balancing the amounts of ARA and DHA as too much DHA may suppress the benefits provided by ARA. Both ARA and DHA have been added to infant formulas and follow-on formulas for more than two decades. The amounts and ratios of ARA and DHA needed in infant formula are discussed based on an in depth review of the available scientific evidence. PMID:27077882

  11. Dietary arachidonic acid in perinatal nutrition: a commentary.

    PubMed

    Lauritzen, Lotte; Fewtrell, Mary; Agostoni, Carlo

    2015-01-01

    Arachidonic acid (AA) is supplied together with docosahexaenoic acid (DHA) in infant formulas, but we have limited knowledge about the effects of supplementation with either of these long-chain polyunsaturated fatty acids (LCPUFA) on growth and developmental outcomes. AA is present in similar levels in breast milk throughout the world, whereas the level of DHA is highly diet dependent. Autopsy studies show similar diet-dependent variation in brain DHA, whereas AA is little affected by intake. Early intake of DHA has been shown to affect visual development, but the effect of LCPUFA on neurodevelopment remains to be established. Few studies have found any functional difference between infants supplemented with DHA alone compared to DHA+AA, but some studies show neurodevelopmental advantages in breast-fed infants of mothers supplemented with n-3 LCPUFA alone. It also remains to be established whether the AA/DHA balance could affect allergic and inflammatory outcomes later in life. Disentangling effects of genetic variability and dietary intake on AA and DHA-status and on functional outcomes may be an important step in the process of determining whether AA-intake is of any physiological or clinical importance. However, based on the current evidence we hypothesize that dietary AA plays a minor role on growth and development relative to the impact of dietary DHA.

  12. Ancestral genetic complexity of arachidonic acid metabolism in Metazoa.

    PubMed

    Yuan, Dongjuan; Zou, Qiuqiong; Yu, Ting; Song, Cuikai; Huang, Shengfeng; Chen, Shangwu; Ren, Zhenghua; Xu, Anlong

    2014-09-01

    Eicosanoids play an important role in inducing complex and crucial physiological processes in animals. Eicosanoid biosynthesis in animals is widely reported; however, eicosanoid production in invertebrate tissue is remarkably different to vertebrates and in certain respects remains elusive. We, for the first time, compared the orthologs involved in arachidonic acid (AA) metabolism in 14 species of invertebrates and 3 species of vertebrates. Based on parsimony, a complex AA-metabolic system may have existed in the common ancestor of the Metazoa, and then expanded and diversified through invertebrate lineages. A primary vertebrate-like AA-metabolic system via cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome P450 (CYP) pathways was further identified in the basal chordate, amphioxus. The expression profiling of AA-metabolic enzymes and lipidomic analysis of eicosanoid production in the tissues of amphioxus supported our supposition. Thus, we proposed that the ancestral complexity of AA-metabolic network diversified with the different lineages of invertebrates, adapting with the diversity of body plans and ecological opportunity, and arriving at the vertebrate-like pattern in the basal chordate, amphioxus.

  13. Arachidonic acid metabolism in fibroblasts derived from canine myocardium

    SciTech Connect

    Weber, D.R.; Prescott, S.M.

    1986-03-05

    Canine fibroblasts from normal or healing infarcted myocardium were grown in culture. The cells were morphologically indistinguishable, but the doubling time of cells from healing myocardium was 39.6 +/- 3.5 hr whereas that of normals was 24 +/- 3.7 (n=5, p < .025). Fibroblasts incorporated (/sup 3/H)arachidonate (AA) into phospholipids. Calcium ionophore A23187 (10 ..mu..M) caused release and metabolism of (/sup 3/H) AA. A23187 or AA (10..mu..M) induced production of 6-keto PGF1..cap alpha.., PGE2, and a hydroxy metabolite of AA. RIA of 6-keto PGF1..cap alpha.. showed that subconfluent cells from healing myocardium produced 1202 +/- 354 pg/mg protein whereas that of normals was 551 +/- 222 (n=7, p < .025). Histamine and bradykinin also induced AA metabolism but were less potent. They examined the effect of AA released from deteriorating myocytes on AA metabolism by cultured fibroblasts. They confirmed that isolated myocytes labelled with (/sup 3/H)AA released but did not metabolize (/sup 3/H)AA. In coincubations, fibroblasts incorporated myocyte-derived AA. Subsequent stimulation of the fibroblasts with A23187 induced the synthesis of 6-keto PGF1..cap alpha.., PGE2 and a hydroxy metabolite. The fibroblast content of healing myocardium was 35-1000 times that of normal tissue (n=7). Thus even a moderate change in AA metabolism, amplified by the AA released from deteriorating myocytes, may be a significant physiologic or pathologic event.

  14. Arachidonate 12-lipoxygenases with reference to their selective inhibitors

    SciTech Connect

    Yamamoto, Shozo . E-mail: yamamosh@kyoto-wu.ac.jp; Katsukawa, Michiko; Nakano, Ayumi; Hiraki, Emi; Nishimura, Kohji; Jisaka, Mitsuo; Yokota, Kazushige; Ueda, Natsuo

    2005-12-09

    Lipoxygenase is a dioxygenase recognizing a 1-cis,4-cis-pentadiene of polyunsaturated fatty acids. The enzyme oxygenates various carbon atoms of arachidonic acid as a substrate and produces 5-, 8-, 12- or 15-hydroperoxy eicosatetraenoic acid with a conjugated diene chromophore. The enzyme is referred to as 5-, 8-, 12- or 15-lipoxygenase, respectively. Earlier we found two isoforms of 12-lipoxygenase, leukocyte- and platelet-type enzymes, which were distinguished by substrate specificity, catalytic activity, primary structure, gene intron size, and antigenicity. Recently, the epidermis-type enzyme was found as the third isoform. Attempts have been made to find isozyme-specific inhibitors of 12-lipoxygenase, and earlier we found hinokitol, a tropolone, as a potent inhibitor selective for the platelet-type 12-lipoxygenase. More recently, we tested various catechins of tea leaves and found that (-)-geotechnical gallate was a potent and selective inhibitor of human platelet 12-lipoxygenase with an IC{sub 5} of 0.14 {mu}M. The compound was much less active with 12-lipoxygenase of leukocyte-type, 15-, 8-, and 5-lipoxygenases, and cyclo oxygenases-1 and -2.

  15. Ancestral genetic complexity of arachidonic acid metabolism in Metazoa.

    PubMed

    Yuan, Dongjuan; Zou, Qiuqiong; Yu, Ting; Song, Cuikai; Huang, Shengfeng; Chen, Shangwu; Ren, Zhenghua; Xu, Anlong

    2014-09-01

    Eicosanoids play an important role in inducing complex and crucial physiological processes in animals. Eicosanoid biosynthesis in animals is widely reported; however, eicosanoid production in invertebrate tissue is remarkably different to vertebrates and in certain respects remains elusive. We, for the first time, compared the orthologs involved in arachidonic acid (AA) metabolism in 14 species of invertebrates and 3 species of vertebrates. Based on parsimony, a complex AA-metabolic system may have existed in the common ancestor of the Metazoa, and then expanded and diversified through invertebrate lineages. A primary vertebrate-like AA-metabolic system via cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome P450 (CYP) pathways was further identified in the basal chordate, amphioxus. The expression profiling of AA-metabolic enzymes and lipidomic analysis of eicosanoid production in the tissues of amphioxus supported our supposition. Thus, we proposed that the ancestral complexity of AA-metabolic network diversified with the different lineages of invertebrates, adapting with the diversity of body plans and ecological opportunity, and arriving at the vertebrate-like pattern in the basal chordate, amphioxus. PMID:24801744

  16. DOCOSAHEXAENOIC ACID AND ARACHIDONIC ACID PREVENT ESSENTIAL FATTY ACID DEFICIENCY AND HEPATIC STEATOSIS

    PubMed Central

    Le, Hau D.; Meisel, Jonathan A.; de Meijer, Vincent E.; Fallon, Erica M.; Gura, Kathleen M.; Nose, Vania; Bistrian, Bruce R.; Puder, Mark

    2012-01-01

    Objectives Essential fatty acids are important for growth, development, and physiologic function. Alpha-linolenic acid and linoleic acid are the precursors of docosahexaenoic and arachidonic acid, respectively, and have traditionally been considered the essential fatty acids. However, we hypothesized that docosahexaenoic acid and arachidonic acid can function as the essential fatty acids. Methods Using a murine model of essential fatty acid deficiency and consequent hepatic steatosis, we provided mice with varying amounts of docosahexaenoic and arachidonic acids to determine whether exclusive supplementation of docosahexaenoic and arachidonic acids could prevent essential fatty acid deficiency and inhibit or attenuate hepatic steatosis. Results Mice supplemented with docosahexaenoic and arachidonic acids at 2.1% or 4.2% of their calories for 19 days had normal liver histology and no biochemical evidence of essential fatty acid deficiency, which persisted when observed after 9 weeks. Conclusion Supplementation of sufficient amounts of docosahexaenoic and arachidonic acids alone without alpha-linolenic and linoleic acids meets essential fatty acid requirements and prevents hepatic steatosis in a murine model. PMID:22038210

  17. In vitro release of arachidonic acid and in vivo responses to respirable fractions of cotton dust

    SciTech Connect

    Thomson, T.A.; Edwards, J.H.; Al-Zubaidy, T.S.; Brown, R.C.; Poole, A.; Nicholls, P.J.

    1986-04-01

    It was considered that the fall in lung function seen after exposure to cotton dust may be attributable in part to the activity of arachidonic acid metabolites, such as leucotrienes as well as to the more established release of histamine by cotton dust. However, we found that cotton and barley dusts elicited poor release of arachidonic acid from an established macrophage like cell line compared with that observed with other organic dusts. In the experimental animal, pulmonary cellular responses to both cotton and barley dust were similar to those evoked by moldy hay and pigeon dropping dusts, although after multiple doses a more severe response was seen to cotton and barley. Since both moldy hay and pigeon droppings elicit a greater arachidonic acid release than cotton or barley, a role for arachidonic acid in inducing the cellular response is less likely than other factors. There are limitations to our conclusions using this system, i.e., the arachidonic acid may be released in a nonmetabolized form, although it is noted that the two dusts with the greatest arachidonic acid release produce their clinical responses in humans largely by hypersensitivity mechanisms.

  18. Arachidonic acid-induced oxidative injury to cultured spinal cord neurons.

    PubMed

    Toborek, M; Malecki, A; Garrido, R; Mattson, M P; Hennig, B; Young, B

    1999-08-01

    Spinal cord trauma can cause a marked release of free fatty acids, in particular, arachidonic acid (AA), from cell membranes. Free fatty acids, and AA by itself, may lead to secondary damage to spinal cord neurons. To study this hypothesis, cultured spinal cord neurons were exposed to increasing concentrations of AA (0.01-10 microM). AA-induced injury to spinal cord neurons was assessed by measurements of cellular oxidative stress, intracellular calcium levels, activation of nuclear factor-KB (NF-kappaB), and cell viability. AA treatment increased intracellular calcium concentrations and decreased cell viability. Oxidative stress increased significantly in neurons exposed to 1 and 10 microM AA. In addition, AA treatment activated NF-kappaB and decreased levels of the inhibitory subunit, IKB. It is interesting that manganese superoxide dismutase protein levels and levels of intracellular total glutathione increased in neurons exposed to this fatty acid for 24 h, consistent with a compensatory response to increased oxidative stress. These results strongly support the hypothesis that free fatty acids contribute to the tissue injury observed following spinal cord trauma. PMID:10428065

  19. The Polyunsaturated Fatty Acids Arachidonic Acid and Docosahexaenoic Acid Induce Mouse Dendritic Cells Maturation but Reduce T-Cell Responses In Vitro

    PubMed Central

    Carlsson, Johan A.; Wold, Agnes E.; Sandberg, Ann-Sofie; Östman, Sofia M.

    2015-01-01

    Long-chain polyunsaturated fatty acids (PUFAs) might regulate T-cell activation and lineage commitment. Here, we measured the effects of omega-3 (n-3), n-6 and n-9 fatty acids on the interaction between dendritic cells (DCs) and naïve T cells. Spleen DCs from BALB/c mice were cultured in vitro with ovalbumin (OVA) with 50 μM fatty acids; α-linolenic acid, arachidonic acid (AA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), linoleic acid or oleic acid and thereafter OVA-specific DO11.10 T cells were added to the cultures. Fatty acids were taken up by the DCs, as shown by gas chromatography analysis. After culture with arachidonic acid or DHA CD11c+ CD11b+ and CD11c+ CD11bneg DCs expressed more CD40, CD80, CD83, CD86 and PDL-1, while IAd remained unchanged. However, fewer T cells co-cultured with these DCs proliferated (CellTrace Violetlow) and expressed CD69 or CD25, while more were necrotic (7AAD+). We noted an increased proportion of T cells with a regulatory T cell (Treg) phenotype, i.e., when gating on CD4+ FoxP3+ CTLA-4+, CD4+ FoxP3+ Helios+ or CD4+ FoxP3+ PD-1+, in co-cultures with arachidonic acid- or DHA-primed DCs relative to control cultures. The proportion of putative Tregs was inversely correlated to T-cell proliferation, indicating a suppressive function of these cells. With arachidonic acid DCs produced higher levels of prostaglandin E2 while T cells produced lower amounts of IL-10 and IFNγ. In conclusion arachidonic acid and DHA induced up-regulation of activation markers on DCs. However arachidonic acid- and DHA-primed DCs reduced T-cell proliferation and increased the proportion of T cells expressing FoxP3, indicating that these fatty acids can promote induction of regulatory T cells. PMID:26619195

  20. Fish oil supplementation maintains adequate plasma arachidonate in cats, but similar amounts of vegetable oils lead to dietary arachidonate deficiency from nutrient dilution.

    PubMed

    Angell, Rebecca J; McClure, Melena K; Bigley, Karen E; Bauer, John E

    2012-05-01

    Because fatty acid (FA) metabolism of cats is unique, effects of dietary fish and vegetable oil supplementation on plasma lipids, lipoproteins, lecithin/cholesterol acyl transferase activities, and plasma phospholipid and esterified cholesterol (EC) FAs were investigated. Cats were fed a commercial diet supplemented with 8 g oil/100 g diet for 4 weeks using either high-oleic-acid sunflower oil (diet H), Menhaden fish oil (diet M), or safflower oil (diet S). When supplemented, diet M contained sufficient arachidonate (AA), but diets H and S were deficient. We hypothesized that diet M would modify plasma lipid metabolism, increase FA long-chain n-3 (LCn-3) FA content but not deplete AA levels. Also, diet S would show linoleic acid (LA) accumulation without conversion to AA, and both vegetable oil supplements would dilute dietary AA content when fed to meet cats' energy needs. Plasma samples on weeks 0, 2, and 4 showed no alterations in total cholesterol or nonesterified FA concentrations. Unesterified cholesterol decreased and EC increased in all groups, whereas lecithin/cholesterol acyl transferase activities were unchanged. Diet M showed significant triacylglycerol lowering and decreased pre-β-lipoprotein cholesterol. Plasma phospholipid FA profiles revealed significant enrichment of 18:1n-9 with diet H, LA and 20:2n-6 with diet S, and FA LCn-3FA with diet M. Depletion of AA was observed with diets H and S but not with diet M. Diet M EC FA profiles revealed specificities for LA and 20:5n-3 but not 22:5n-3 or 22:6n-3. Oversupplementation of some commercial diets with vegetable oils causes AA depletion in young cats due to dietary dilution. Findings are consistent with the current recommendations for at least 0.2 g AA/kg diet and that fish oil supplements provide both preformed LCn-3 polyunsaturated FA and AA.

  1. Light-evoked arachidonic acid release in the retina: illuminance/duration dependence and the effects of quinacrine, mellitin and lithium. Light-evoked arachidonic acid release.

    PubMed

    Jung, H; Remé, C

    1994-03-01

    Arachidonic acid (AA) is the precursor molecule of a variety of cellular lipid mediators that interact with retinal physiology. In this study, we investigated the time- and illuminance-dependence of the release of AA in the rat retina in vitro in control and lithium-pretreated rats. We also studied the effects of the specific phospholipase A2 (PLA2) inhibitor quinacrine and the specific PLA2 stimulator mellitin on the release of AA. Isolated rat retinas were labelled with 3H-AA for 90 min in vitro in darkness and the incorporation of AA into retinal phospholipids was monitored by thin-layer chromatography. The release of 3H-AA in the incubation medium was determined under different illuminance and timing conditions, with the addition of quinacrine and mellitin, and after pretreatment of the animals with lithium. Light exposure of the prelabelled isolated retinas evoked up to a two-fold increase in AA release compared with retinas incubated for the same time in darkness. The AA release was dependent on illuminance time (10,000 1x white fluorescent light for 0.25, 2, 5 and 10 min) and illuminance level (0, 100, 1000, 5000, and 10,000 1x for 10 min). Complete rhodopsin bleaching occurred after 2 min at 10,000 1x. Quinacrine significantly suppressed the light-elicited AA release whereas mellitin increased the release of AA in dark-adapted and light-exposed retinas. Lithium pretreatment, which is known to potentiate light-evoked rod outer segment disruptions, significantly augmented the light-evoked AA release. Our results confirm a light-stimulated release of AA in the retina.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Arachidonate 5-lipoxygenase (ALOX5) gene polymorphism is associated with Alzheimer's disease and body mass index.

    PubMed

    Šerý, Omar; Hlinecká, Lýdia; Povová, Jana; Bonczek, Ondřej; Zeman, Tomáš; Janout, Vladimír; Ambroz, Petr; Khan, Naim A; Balcar, Vladimir J

    2016-03-15

    Dementias of old age, in particular Alzheimer's disease (AD), pose a growing threat to the longevity and quality of life of individuals as well as whole societies world-wide. The risk factors are both genetic and environmental (life-style) and there is an overlap with similar factors predisposing to cardiovascular diseases (CVD). Using a case-control genetic approach, we have identified a SNP (rs10507391) in ALOX5 gene, previously associated with an increased risk of stroke, as a novel genetic risk factor for AD. ALOX5 gene encodes a 5'-lipoxygenase (5'-LO) activating protein (FLAP), a crucial component of the arachidonic acid/leukotriene inflammatory cascade. A-allele of rs4769874 polymorphism increases the risk of AD 1.41-fold (p<0.0001), while AA genotype does so 1.79-fold (p<0.0001). In addition, GG genotype of rs4769874 polymorphism is associated with a modest increase in body mass index (BMI). We discuss potential biochemical mechanisms linking the SNP to AD and suggest possible preventive pharmacotherapies some of which are based on commonly available natural products. Finally, we set the newly identified AD risk factors into a broader context of similar CVD risk factors to generate a more comprehensive picture of interacting genetics and life-style habits potentially leading to the deteriorating mental health in the old age. PMID:26944113

  3. Pharmacological manipulation of arachidonic acid-epoxygenase results in divergent effects on renal damage.

    PubMed

    Li, Jing; Stier, Charles T; Chander, Praveen N; Manthati, Vijay L; Falck, John R; Carroll, Mairéad A

    2014-01-01

    Kidney damage is markedly accelerated by high-salt (HS) intake in stroke-prone spontaneously hypertensive rats (SHRSP). Epoxyeicosatrienoic acids (EETs) are epoxygenase products of arachidonic acid which possess vasodepressor, natriuretic, and anti-inflammatory activities. We examined whether up-regulation (clofibrate) or inhibition [N-methylsulfonyl-6-(2-propargyloxyphenyl)hexanamide (MS-PPOH)] of epoxygenase would alter systolic blood pressure (SBP) and/or renal pathology in SHRSP on HS intake (1% NaCl drinking solution). Three weeks of treatment with clofibrate induced renal cortical protein expression of CYP2C23 and increased urinary excretion of EETs compared with vehicle-treated SHRSP. SBP and urinary protein excretion (UPE) were significantly lowered with clofibrate treatment. Kidneys from vehicle-treated SHRSP, which were on HS intake for 3 weeks, demonstrated focal lesions of vascular fibrinoid degeneration, which were markedly attenuated with clofibrate treatment. In contrast, 2 weeks of treatment with the selective epoxygenase inhibitor, MS-PPOH, increased UPE without significantly altering neither urinary EET levels nor SBP. Kidneys from vehicle-treated SHRSP, which were on HS intake for 11 days, demonstrated occasional mild damage whereas kidneys from MS-PPOH-treated rats exhibited widespread malignant nephrosclerosis. These results suggest that pharmacological manipulation of epoxygenase results in divergent effects on renal damage and that interventions to increase EET levels may provide therapeutic strategies for treating salt-sensitive hypertension and renal damage.

  4. Anti-inflammatory effects of chronic aspirin on brain arachidonic acid metabolites.

    PubMed

    Basselin, Mireille; Ramadan, Epolia; Chen, Mei; Rapoport, Stanley I

    2011-01-01

    Pro-inflammatory and anti-inflammatory mediators derived from arachidonic acid (AA) modulate peripheral inflammation and its resolution. Aspirin (ASA) is a unique non-steroidal anti-inflammatory drug, which switches AA metabolism from prostaglandin E₂ (PGE₂) and thromboxane B₂ (TXB₂) to lipoxin A₄ (LXA₄) and 15-epi-LXA₄. However, it is unknown whether chronic therapeutic doses of ASA are anti-inflammatory in the brain. We hypothesized that ASA would dampen increases in brain concentrations of AA metabolites in a rat model of neuroinflammation, produced by a 6-day intracerebroventricular infusion of bacterial lipopolysaccharide (LPS). In rats infused with LPS (0.5 ng/h) and given ASA-free water to drink, concentrations in high-energy microwaved brain of PGE₂, TXB₂ and leukotriene B₄ (LTB₄) were elevated. In rats infused with artificial cerebrospinal fluid, 6 weeks of treatment with a low (10 mg/kg/day) or high (100 mg/kg/day) ASA dose in drinking water decreased brain PGE₂, but increased LTB₄, LXA₄ and 15-epi-LXA₄ concentrations. Both doses attenuated the LPS effects on PGE₂, and TXB₂. The increments in LXA₄ and 15-epi-LXA₄ caused by high-dose ASA were significantly greater in LPS-infused rats. The ability of ASA to increase anti-inflammatory LXA₄ and 15-epi-LXA₄ and reduce pro-inflammatory PGE₂ and TXB₂ suggests considering aspirin further for treating clinical neuroinflammation. PMID:20981485

  5. Activation of the central histaminergic system mediates arachidonic-acid-induced cardiovascular effects.

    PubMed

    Altinbas, Burcin; Topuz, Bora Burak; İlhan, Tuncay; Yilmaz, Mustafa Sertac; Erdost, Hatice; Yalcin, Murat

    2014-08-01

    The aim of this study was to explain the involvement of the central histaminergic system in arachidonic acid (AA)-induced cardiovascular effects in normotensive rats using hemodynamic, immunohistochemistry, and microdialysis studies. Intracerebroventricularly (i.c.v.) administered AA (0.25, 0.5, and 1.0 μmol) induced dose- and time-dependent increases in mean arterial pressure and decreased heart rate in conscious normotensive Sprague-Dawley rats. Central injection of AA (0.5 μmol) also increased posterior hypothalamic extracellular histamine levels and produced strong COX-1 but not COX-2 immunoreactivity in the posterior hypothalamus of rats. Moreover, the cardiovascular effects and COX-1 immunoreactivity in the posterior hypothalamus induced by AA (0.5 μmol; i.c.v.) were almost completely blocked by the H2 receptor antagonist ranitidine (50 and 100 nmol; i.c.v.) and partially blocked by the H1 receptor blocker chlorpheniramine (100 nmol; i.c.v.) and the H3-H4 receptor antagonist thioperamide (50 and 100 nmol; i.c.v.). In conclusion, these results indicate that centrally administered AA induces pressor and bradycardic responses in conscious rats. Moreover, we suggest that AA may activate histaminergic neurons and increase extracellular histamine levels, particularly in the posterior hypothalamus. Acting as a neurotransmitter, histamine is potentially involved in AA-induced cardiovascular effects under normotensive conditions.

  6. Kinetic investigation of human 5-lipoxygenase with arachidonic acid.

    PubMed

    Mittal, Monica; Kumar, Ramakrishnan B; Balagunaseelan, Navisraj; Hamberg, Mats; Jegerschöld, Caroline; Rådmark, Olof; Haeggström, Jesper Z; Rinaldo-Matthis, Agnes

    2016-08-01

    Human 5-lipoxygenase (5-LOX) is responsible for the formation of leukotriene (LT)A4, a pivotal intermediate in the biosynthesis of the leukotrienes, a family of proinflammatory lipid mediators. 5-LOX has thus gained attention as a potential drug target. However, details of the kinetic mechanism of 5-LOX are still obscure. In this Letter, we investigated the kinetic isotope effect (KIE) of 5-LOX with its physiological substrate, arachidonic acid (AA). The observed KIE is 20±4 on kcat and 17±2 on kcat/KM at 25°C indicating a non-classical reaction mechanism. The observed rates show slight temperature dependence at ambient temperatures ranging from 4 to 35°C. Also, we observed low Arrhenius prefactor ratio (AH/AD=0.21) and a small change in activation energy (Ea(D)-Ea(H)=3.6J/mol) which suggests that 5-LOX catalysis involves tunneling as a mechanism of H-transfer. The measured KIE for 5-LOX involves a change in regioselectivity in response to deuteration at position C7, resulting in H-abstraction form C10 and formation of 8-HETE. The viscosity experiments influence the (H)kcat, but not (D)kcat. However the overall kcat/KM is not affected for labeled or unlabeled AA, suggesting that either the product release or conformational rearrangement might be involved in dictating kinetics of 5-LOX at saturating conditions. Investigation of available crystal structures suggests the role of active site residues (F421, Q363 and L368) in regulating the donor-acceptor distances, thus affecting H-transfer as well as regiospecificity. In summary, our study shows that that the H-abstraction is the rate limiting step for 5-LOX and that the observed KIE of 5-LOX is masked by a change in regioselectivity. PMID:27363940

  7. Expression of NO-synthase in cells of foreign-body and BCG-induced granulomata in mice: influence of L-NAME on the evolution of the lesion.

    PubMed Central

    Kreuger, M R; Tames, D R; Mariano, M

    1998-01-01

    The microbicidal activity of macrophages in an inflammatory milieu has been related to the production of a large number of cytokins and intermediary metabolites of oxygen and nitrogen among them, nitric oxide (NO). Considering that granulomatous inflammation is predominantly composed of macrophages and epithelioid cells, we decided to investigate the participation of NO in this peculiar type of inflammation. Two models were used: glass cover slip implantation into the subcutaneous tissue of mice and, the inoculation of live bacillus Calmette-Guérin (BCG) into the footpad of the animals. Using a histochemical method for the detection of NO synthase and of the concentration of citrulin metabolized by cells obtained from cover slips implanted on different time intervals or BCG-activated peritoneal cells, it was possible to demonstrate that epithelioid cells do not produce NO. Cells from granuloma induced by BCG inoculation express NO synthase, with different degrees of reactivity with a higher intensity in the cytoplasm of cells located in the edge of the lesions. The expression of NO synthase in the cytoplasm of these cells decreases with the age of the lesions. It could also be demonstrated that in mice treated with l-name, an inhibitor of NO metabolism, the lesions induced by BCG lost the granulomatous architecture, were necrotic, and had a significant increase in the bacillary load of the lesion. These data allow us to conclude that NO production by macrophages is a determining factor in the organization of the granulomatous lesion and that it also controls the bacterial load in BCG-induced lesions in mice. Images Figure 1 Figure 2 Figure 4 Figure 6 PMID:9824487

  8. Lung, aorta, and platelet metabolism of /sup 14/C-arachidonic acid in vitamin E deficient rats

    SciTech Connect

    Valentovic, M.A.; Gairola, C.; Lubawy, W.C.

    1982-08-01

    /sup 14/C-arachidonic acid metabolism was determined in aortas, platelets, and perfused lungs from rats pair fed a basal diet supplemented with 0 or 100 ppm vitamin E for 11 weeks. Spontaneous erythrocyte hemolysis tests showed 92% and 8% hemolysis for the 0 and 100 ppm vitamin E groups, respectively. Elevated lung homogenate levels of malonaldehyde in the 0 ppm group confirmed its deficient vitamin E status. Aortas from the vitamin E deficient group synthesized 54% less prostacyclin than aortas from the supplemented group (p less than 0.05). Although thromboxane generation by platelets from the vitamin E deficient group exhibited a 37% increase, this difference was not statistically significant compared to the supplemented animals. Greater amounts of PGE2, PGF2 alpha, TXB2, and 6-keto-PGF1 alpha were obtained in albumin buffer perfusates from lungs of vitamin E deficient rats than in those from supplemented rats. Significant differences (p less than 0.05) were noticed, however, only for PGE2 and PGF2 alpha. These studies indicate that vitamin E quantitatively alters arachidonic acid metabolism in aortic and lung tissue but its effect on thromboxane synthesis by platelets is less marked.

  9. Arachidonic Acid Enhances Reproduction in Daphnia magna and Mitigates Changes in Sex Ratios Induced by Pyriproxyfen

    PubMed Central

    Ginjupalli, Gautam K.; Gerard, Patrick D.; Baldwin, William S.

    2016-01-01

    Arachidonic acid (AA) is one of only two unsaturated fatty acids retained in the ovaries of crustaceans, and an inhibitor of HR97g, a nuclear receptor expressed in adult ovaries. We hypothesized that as a key fatty acid, AA may be associated with reproduction and potentially environmental sex determination in Daphnia. Reproduction assays with AA indicate that it alters female/male sex ratios by increasing female production. This reproductive effect only occurred during a restricted P. subcapitata diet. Next, we tested whether enriching a poorer algal diet (C. vulgaris) with AA enhances overall reproduction and sex ratios. AA enrichment of a C. vulgaris diet also enhances fecundity at 1.0 and 4.0μM by 30–40% in the presence and absence of pyriproxyfen. This indicates that AA is crucial in reproduction regardless of environmental sex determination. Furthermore, our data indicates that P. subcapitata may provide a threshold concentration of AA needed for reproduction. Diet switch experiments from P. subcapitata to C. vulgaris mitigate some but not all of AA’s effects when compared to a C. vulgaris only diet, suggesting that some AA provided by P. subcapitata is retained. In summary, AA supplementation increases reproduction and represses pyriproxyfen-induced environmental sex determination in D. magna in restricted diets. A diet rich in AA may provide protection from some reproductive toxicants such as the juvenile hormone agonist, pyriproxyfen. PMID:25393616

  10. Improving arachidonic acid fermentation by Mortierella alpina through multistage temperature and aeration rate control in bioreactor.

    PubMed

    Gao, Min-Jie; Wang, Cheng; Zheng, Zhi-Yong; Zhu, Li; Zhan, Xiao-Bei; Lin, Chi-Chung

    2016-05-18

    Effective production of arachidonic acid (ARA) using Mortierella alpina was conducted in a 30-L airlift bioreactor. Varying the aeration rate and temperature significantly influenced cell morphology, cell growth, and ARA production, while the optimal aeration rate and temperature for cell growth and product formation were quite different. As a result, a two-stage aeration rate control strategy was constructed based on monitoring of cell morphology and ARA production under various aeration rate control levels (0.6-1.8 vvm). Using this strategy, ARA yield reached 4.7 g/L, an increase of 38.2% compared with the control (constant aeration rate control at 1.0 vvm). Dynamic temperature-control strategy was implemented based on the fermentation performance at various temperatures (13-28°C), with ARA level in total cellular lipid increased by 37.1% comparing to a constant-temperature control (25°C). On that basis, the combinatorial fermentation strategy of two-stage aeration rate control and dynamic temperature control was applied and ARA production achieved the highest level of 5.8 g/L.

  11. Arachidonate 5 Lipoxygenase Expression in Papillary Thyroid Carcinoma Promotes Invasion via MMP-9 Induction

    PubMed Central

    Kummer, Nicolas T.; Nowicki, Theodore S; Azzi, Jean Paul; Reyes, Ismael; Iacob, Codrin; Xie, Suqing; Swati, Ismatun; Suslina, Nina; Schantz, Stimson; Tiwari, Raj K.; Geliebter, Jan

    2012-01-01

    Arachidonate 5-lipoxygenase (ALOX5) expression and activity has been implicated in tumor pathogenesis, yet its role in papillary thyroid carcinoma (PTC) has not been characterized. ALOX5 protein and mRNA were upregulated in PTC compared to matched, normal thyroid tissue, and ALOX5 expression correlated with invasive tumor histopathology. Evidence suggests that PTC invasion is mediated through the induction of matrix metalloproteinases (MMPs) that can degrade and remodel the extracellular matrix (ECM). A correlation between MMP-9 and ALOX5 protein expression was established by immunohistochemical analysis of PTC and normal thyroid tissues using a tissue array. Transfection of ALOX5 into a PTC cell line (BCPAP) increased MMP-9 secretion and cell invasion across an ECM barrier. The ALOX5 product, 5(S)-hydroxyeicosatetraenoic acid also increased MMP-9 protein expression by BCPAP in a dose-dependent manner. Inhibitors of MMP-9 and ALOX5 reversed ALOX5-enhanced invasion. Here we describe a new role for ALOX5 as a mediator of invasion via MMP-9 induction; this ALOX5/MMP9 pathway represents a new avenue in the search for functional biomarkers and/or potential therapeutic targets for aggressive PTC. PMID:22253131

  12. Impact of Arachidonic Acid and the Leukotriene Signaling Pathway on Vasculogenesis of Mouse Embryonic Stem Cells.

    PubMed

    Huang, Yu-Han; Sharifpanah, Fatemeh; Becker, Sven; Wartenberg, Maria; Sauer, Heinrich

    2016-01-01

    Embryonic stem (ES) cells can differentiate into various kinds of cells, such as endothelial and hematopoietic cells. In addition, some evidence suggests that inflammatory mediators such as leukotrienes (LTs), which include the 5-lipoxygenase (LOX) family, can regulate endothelial cell differentiation. In the present study, the eicosanoid precursor arachidonic acid (AA) stimulated vasculogenesis of ES cells by increasing the number of fetal liver kinase-1+ vascular progenitor cells as well as vascular structures positive for platelet endothelial cell adhesion protein-1 and vascular endothelial cadherin. The stimulation of vasculogenesis and expression of the rate-limiting enzyme in the LT signaling pathway, 5-LOX-activating protein (FLAP), was blunted upon treatment with the FLAP inhibitors AM643 and REV5901. Vasculogenesis was significantly restored upon exogenous addition of LTs. Downstream of FLAP, the LTB4 receptor (BLT1) blocker U75302, the BLT2 receptor blocker LY255283 as well as the cysteinyl LT blocker BAY-u9773 inhibited vasculogenesis of ES cells. AA treatment of differentiating ES cells increased reactive oxygen species (ROS) generation, which was not affected upon either FLAP or cyclooxygenase-2 inhibition. Prevention of ROS generation by either the free radical scavengers vitamin E and N-(2-mercaptopropionyl)glycine or the NADPH oxidase inhibitor VAS2870 downregulated vasculogenesis of ES cells and blunted the provasculogenic effect of AA. In summary, our data demonstrate that proinflammatory AA stimulates vasculogenesis of ES cells via the LT pathway by mechanisms involving ROS generation. PMID:27198524

  13. Arachidonic acid supply and metabolism in human infants born at full term.

    PubMed

    Koletzko, B; Decsi, T; Demmelmair, H

    1996-01-01

    Infants need arachidonic acid (AA; C20:4n-6) for eicosanoid synthesis and deposition in growing tissues, including brain. Human milk supplies preformed AA in amounts considered to meet accretion in membrane-rich tissues, but vegetable oil-based infant formulas do not contain AA. We studied two groups of ten healthy infants, each fed human milk or formula, and analyzed plasma lipid composition. Percentage contributions of AA to plasma phospholipids were stable over two months after birth in breast-fed infants, but infants fed formula developed significantly (P < 0.05) lower levels at the ages of two weeks (formula 6.9% vs. breast 9.4%, w/w), one month (6.2 vs. 9.1%), and two months (5.7 vs. 8.4%). In a second trial, we randomized infants to receive (from birth to age four months) formula without or with both AA and docosahexaenoic acid (DHA; C22:6n-3) at levels typical for mature human milk. Infants fed conventional formula showed a continuous decrease of phospholipid AA over time, whereas feeding of formula supplemented with AA and DHA led to significantly higher AA levels, similar to those in breast-fed infants (two months: supplemented 9.6% vs. unsupplemented 7.1%; four months: 8.7 vs. 6.6%). In order to estimate infantile capacity for endogenous synthesis of AA, we fed four term neonates with newly diagnosed phenylketonuria (mean age 18 d) a formula with all fat contributed by corn oil, which has a higher natural 13C-enrichment than European human milk or formula. Analysis of 13C-enrichment in plasma fatty acids over four days allowed us to estimate infantile AA synthesis. We found an increased 13C-value in plasma AA of all infants, which indicates that term neonates can synthesize AA. However, with a simplified isotope balance equation, we estimate that endogenous synthesis contributed only about 23% of total plasma arachidonic acid by day four. We conclude that full-term infants fed formula may require a dietary supply of some preformed AA if the biochemical

  14. RAS is required for epidermal growth factor-stimulated arachidonic acid release in rat-1 fibroblasts.

    PubMed

    Warner, L C; Hack, N; Egan, S E; Goldberg, H J; Weinberg, R A; Skorecki, K L

    1993-12-01

    Previous studies have provided suggestive evidence for an interaction between ras activation and signalling pathways involved in agonist-stimulated arachidonic acid release in a variety of cell systems. In order to clarify this interaction, we have measured epidermal growth factor (EGF)-stimulated arachidonic acid release in rat-1 fibroblasts transfected with the N-17 dominant negative mutation of ras. Cells transfected with the N-17 ras mutant, display a markedly attenuated arachidonic acid-release response to EGF, compared to sham-transfected and non-transfected cells. In contrast, the response to phorbol myristate acetate (PMA) was not attenuated in the N-17-mutant expressing cells. No differences were detected between sham-transfected and N-17 mutant expressing cells in levels of immunodetectable EGF receptor, cytosolic phospholipase A2 or mitogen-activated protein (MAP) kinase. Attenuation of EGF-stimulated arachidonic acid release in the N-17 mutant expressing cells, was accompanied by a marked diminution in EGF-stimulated tyrosine phosphorylation of MAP kinase. We conclude that the signalling pathway involved in epidermal growth factor-stimulated arachidonic acid release is similar to the signalling pathway for mitogenic responses to epidermal growth factor and requires ras activation, likely followed by a downstream cascade of kinases eventuating in MAP kinase activation.

  15. Effects of garlic extract and of three pure components isolated from it on human platelet aggregation, arachidonate metabolism, release reaction and platelet ultrastructure.

    PubMed

    Apitz-Castro, R; Cabrera, S; Cruz, M R; Ledezma, E; Jain, M K

    1983-10-15

    We studied the effect of the methanol extract of garlic bulbs (EOG) and of three pure components isolated from it (F1, F2, F3), on human platelet aggregation induced by ADP, epinephrine, collagen, thrombin, arachidonate, PAF, and the ionophore A-23187. Incubation of PRP with EOG, either in methanol or in homologous PPP, inhibits platelet aggregation induced by all of the above mentioned agonists. F1, F2, and F3 also inhibit platelet aggregation, however, F3 was about four times more potent. Addition of EOG or F3 to platelets that have already been irreversibly aggregated by 10 microM ADP, induces rapid deaggregation. Inhibition of aggregation was still present after three hours. The inhibitory effect persisted even after the treated platelets were Gel-Filtered (GFP) or separated from plasma through a metrizamide gradient and resuspended in new homologous PPP. Thrombin-induced release of ATP from GFP was inhibited by 75-80% after EOG or F3 treatment. Incorporation of [3-H]-arachidonate by intact platelets was decreased by 50-60% in treated platelets. However, platelets incubated with the inhibitors after incorporation of radiolabeled arachidonate, although did not aggregate, produced, after thrombin activation similar amounts of radiolabeled TXB2 and lipoxygenase products as the controls. Electron microscopy of inhibited platelets, in the presence of thrombin, showed no degranulation but an increase of spherical forms. Our results suggest that the effects described might be mediate by a perturbation of the physicochemical properties of the plasma membrane rather than by affecting arachidonate or calcium metabolism in the cells. Chemical structures of F1, F2 and F3 have been provisionally assigned: F1 is diallytrisulfide, F2 is 2-vinyl-1,3-dithiene, and F3 is most probably allyl 1,5-hexadienyltrisulfide. PMID:6419374

  16. The effect of the menstrual cycle and of decompression stress on arachidonic acid-induced platelet aggregation and on intrinsic platelet thromboxane production in women compared with men.

    PubMed

    Markham, S M; Dubin, N H; Rock, J A

    1991-12-01

    Menstrual cycle variations in platelet aggregation and thromboxane production in association with sex steroids have been reported. External stimuli such as decompression sickness have been associated with clotting activity changes, specifically, increased platelet aggregation. Differences in response of platelets from women and men, when subjected to such a stress, have been observed. This study evaluated the ability of washed platelets from women in the proliferative and secretory phases of the menstrual cycle to aggregate in response to arachidonic acid and the aggregation difference between washed platelets from women and men in response to decompression stress and arachidonic acid. Additionally, platelet thromboxane production differences between the assessed platelet populations were compared. Our results indicate no difference in platelet aggregability between phases of the menstrual cycle. A significant aggregation difference between platelets from women and men was noted. Platelets from women were more sensitive to arachidonic acid aggregation. These differences were not affected by decompression stress. No difference in thromboxane B2 production was noted between the platelet populations evaluated.

  17. Metabolic fate of arachidonic acid in hepatocytes of continuously endotoxemic rats.

    PubMed Central

    Rodriguez de Turco, E B; Spitzer, J A

    1988-01-01

    The present experiments were designed to characterize the kinetics of [1-14C]arachidonic acid (AA) metabolism as a function of time in hepatocytes obtained from rats infused continuously for 30 h with a nonlethal dose of Escherichia coli endotoxin (ET). Chronic endotoxemia greatly reduces the ability of hepatocytes to utilize [1-14C]AA, which is reflected from the earliest times of incubation in very low labeling of intermediates in the biosynthetic pathways of glycerolipids (phosphatidic acid and diacylglycerol) and slower removal of [1-14C]AA from the free fatty acid pool as compared with saline-infused rats. At later times of incubation, the labeling of phospholipids (especially phosphatidylethanolamine and phosphatidylinositol [PI]), but not of triacylglycerides is decreased. Analysis of fatty acid composition of individual phospholipids from cells of ET-infused rats reveals that the content of AA is significantly reduced only in PI. Hence an impairment in activation/acylation enzymatic mechanisms could affect the turnover of metabolically active phospholipid pools, i.e., PI, involved in signal transmission processes, and result in increased availability of 20:4 for eicosanoid synthesis, contributing to cellular metabolic perturbations in endotoxicosis. PMID:3125225

  18. Arachidonic Acid Monooxygenase: Genetic and Biochemical Approaches to Physiological/Pathophysiological Relevance

    PubMed Central

    Capdevila, Jorge H.; Wang, Wenhui; Falck, John R.

    2015-01-01

    Studies with rat genetic models of hypertension pointed to roles for the CYP2C and CYP4A arachidonic acid epoxygenases and ω-hydroxylases in tubular transport, hemodynamics, and blood pressure control. Further progress in defining their physiological functions and significance to human hypertension requires conclusive identifications of the relevant genes and proteins. Here we discuss unequivocal evidence of roles for the murine Cyp4a14, Cyp4a10, and Cyp2c44 genes in the pathophysiology of hypertension by showing that: a) Cyp4a14(-/-) mice develop sexually dimorphic hypertension associated with renal vasoconstriction, and up-regulated expression of Cyp4a12a and pro-hypertensive 20-hydroxyeicosatetraenoic acid (20-HETE) levels, and b) Cyp4a10(-/-) and Cyp2c44(-/-) mice develop salt sensitive hypertension linked to downregulation or lack of the Cyp2c44 epoxygenase, reductions in anti-hypertensive epoxyeicosatrienoic acids (EETs), and increases in distal sodium reabsorption. Based on these studies, the human CYP4A11 and CYPs 2C8 and 2C9 genes and their products are identified as potential candidates for studies of the molecular basis of human hypertension. PMID:25986599

  19. Arachidonic Acid Randomizes Endothelial Cell Motion and Regulates Adhesion and Migration

    PubMed Central

    Rossen, Ninna Struck; Hansen, Anker Jon; Selhuber-Unkel, Christine; Oddershede, Lene Broeng

    2011-01-01

    Cell adhesion and migration are essential for the evolution, organization, and repair of living organisms. An example of a combination of these processes is the formation of new blood vessels (angiogenesis), which is mediated by a directed migration and adhesion of endothelial cells (ECs). Angiogenesis is an essential part of wound healing and a prerequisite of cancerous tumor growth. We investigated the effect of the amphiphilic compound arachidonic acid (AA) on EC adhesion and migration by combining live cell imaging with biophysical analysis methods. AA significantly influenced both EC adhesion and migration, in either a stimulating or inhibiting fashion depending on AA concentration. The temporal evolution of cell adhesion area was well described by a two-phase model. In the first phase, the spreading dynamics were independent of AA concentration. In the latter phase, the spreading dynamics increased at low AA concentrations and decreased at high AA concentrations. AA also affected EC migration; though the instantaneous speed of individual cells remained independent of AA concentration, the individual cells lost their sense of direction upon addition of AA, thus giving rise to an overall decrease in the collective motion of a confluent EC monolayer into vacant space. Addition of AA also caused ECs to become more elongated, this possibly being related to incorporation of AA in the EC membrane thus mediating a change in the viscosity of the membrane. Hence, AA is a promising non-receptor specific regulator of wound healing and angiogenesis. PMID:21966453

  20. Arachidonic acid impairs hypothalamic leptin signaling and hepatic energy homeostasis in mice.

    PubMed

    Cheng, Licai; Yu, Yinghua; Zhang, Qingsheng; Szabo, Alexander; Wang, Hongqin; Huang, Xu-Feng

    2015-09-01

    Epidemiological evidence suggests that the consumption of a diet high in n-6 polyunsaturated fatty acids (PUFA) is associated with the development of leptin resistance and obesity. We aim to examine the central effect of n-6 PUFA, arachidonic acid (ARA) on leptin sensitivity and leptin-regulated hepatic glucose and lipid metabolism. We found that intracerebroventricular injection of ARA (25 nmol/day) for 2.5 days reversed the effect of central leptin on hypothalamic JAK2, pSTAT3, pAkt, and pFOXO1 protein levels, which was concomitant with a pro-inflammatory response in the hypothalamus. ARA also attenuated the effect of central leptin on hepatic glucose and lipid metabolism by reversing the mRNA expression of the genes involved in gluconeogenesis (G6Pase, PEPCK), glucose transportation (GLUT2), lipogenesis (FAS, SCD1), and cholesterol synthesis (HMG-CoA reductase). These results indicate that an increased exposure to central n-6 PUFA induces central cellular leptin resistance with concomitant defective JAK2-STAT3 and PI3K-Akt signaling.

  1. Effects of Angiotensin II Receptor Blockers on Metabolism of Arachidonic Acid via CYP2C8.

    PubMed

    Senda, Asuna; Mukai, Yuji; Toda, Takaki; Hayakawa, Toru; Yamashita, Miki; Eliasson, Erik; Rane, Anders; Inotsume, Nobuo

    2015-01-01

    Arachidonic acid (AA) is metabolized to epoxyeicosatrienoic acids (EETs) via cytochrome enzymes such as CYP 2C9, 2C8 and 2J2. EETs play a role in cardioprotection and regulation of blood pressure. Recently, adverse reactions such as sudden heart attack and fatal myocardial infarction were reported among patients taking angiotensin II receptor blockers (ARBs). As some ARBs have affinity for these CYP enzymes, metabolic inhibition of AA by ARBs is a possible cause for the increase in cardiovascular events. In this study, we quantitatively investigated the inhibitory effects of ARBs on the formation of EETs and further metabolites, dihydroxyeicosatrienoic acids (DHETs), from AA via CYP2C8. In incubations with recombinant CYP2C8 in vitro, the inhibitory effects were compared by measuring EETs and DHETs by HPLC-MS/MS. Inhibition of AA metabolism by ARBs was detected in a concentration-dependent manner with IC50 values of losartan (42.7 µM), telmisartan (49.5 µM), irbesartan (55.6 µM), olmesartan (66.2 µM), candesartan (108 µM), and valsartan (279 µM). Losartan, telmisartan and irbesartan, which reportedly accumulate in the liver and kidneys, have stronger inhibitory effects than other ARBs. The lower concentration of EETs leads to less protective action on the cardiovascular system and a higher incidence of adverse effects such as sudden heart attack and myocardial infarction in patients taking ARBs. PMID:26632190

  2. Inhibition of arachidonic acid metabolism and its implication on cell proliferation and tumour-angiogenesis.

    PubMed

    Hyde, C A C; Missailidis, S

    2009-06-01

    Arachidonic acid (AA) and its metabolites have recently generated a heightened interest due to growing evidence of their significant role in cancer biology. Thus, inhibitors of the AA cascade, first and foremost COX inhibitors, which have originally been of interest in the treatment of inflammatory conditions and certain types of cardiovascular disease, are now attracting attention as an arsenal against cancer. An increasing number of investigations support their role in cancer chemoprevention, although the precise molecular mechanisms that link levels of AA, and its metabolites, with cancer progression have still to be elucidated. This article provides an overview of the AA cascade and focuses on the roles of its inhibitors and their implication in cancer treatment. In particular, emphasis is placed on the inhibition of cell proliferation and neo-angiogenesis through inhibition of the enzymes COX-2, 5-LOX and CYP450. Downstream effects of inhibition of AA metabolites are analysed and the molecular mechanisms of action of a selected number of inhibitors of catalytic pathways reviewed. Lastly, the benefits of dietary omega-3 fatty acids and their mechanisms of action leading to reduced cancer risk and impeded cancer cell growth are mentioned. Finally, a proposal is put forward, suggesting a novel and integrated approach in viewing the molecular mechanisms and complex interactions responsible for the involvement of AA metabolites in carcinogenesis and the protective effects of omega-3 fatty acids in inflammation and tumour prevention. PMID:19239926

  3. What is the relationship between gestational age and docosahexaenoic acid (DHA) and arachidonic acid (ARA) levels?

    PubMed

    Baack, Michelle L; Puumala, Susan E; Messier, Stephen E; Pritchett, Deborah K; Harris, William S

    2015-09-01

    Long chain polyunsaturated fatty acids (LCPUFA) including docosahexaenoic acid (DHA) and arachidonic acid (ARA) are increasingly transferred from mother to fetus late in pregnancy. Infants born before this transfer is complete are at risk for deficiency. This study determines the relationship between gestational age (GA) and circulating LCPUFA levels to better understand the unique needs of premature infants born at various GAs. Whole blood was collected within the first 7 days of life from 60 preterm (≤34 weeks GA) and 30 term infants (≥38 weeks GA) and FA levels were analyzed. Since concurrent intravenous lipid emulsion can skew composition data, blood LCPUFA concentrations were also measured. Levels were compared among groups, and linear regression models were used to examine the association between FA composition and GA. Preterm infants had significantly lower DHA and ARA levels than term peers, and whether assessed as concentrations or compositions, both directly correlated with GA (p<0.0001). Moreover, FA comparisons suggest that premature infants have impaired synthesis of LCPUFAs from precursors and may require preformed DHA and ARA. This study confirms that essential FA status is strongly related to GA, and that those babies born the earliest are at the greatest risk of LCPUFA deficiency.

  4. Arachidonic acid impairs hypothalamic leptin signaling and hepatic energy homeostasis in mice.

    PubMed

    Cheng, Licai; Yu, Yinghua; Zhang, Qingsheng; Szabo, Alexander; Wang, Hongqin; Huang, Xu-Feng

    2015-09-01

    Epidemiological evidence suggests that the consumption of a diet high in n-6 polyunsaturated fatty acids (PUFA) is associated with the development of leptin resistance and obesity. We aim to examine the central effect of n-6 PUFA, arachidonic acid (ARA) on leptin sensitivity and leptin-regulated hepatic glucose and lipid metabolism. We found that intracerebroventricular injection of ARA (25 nmol/day) for 2.5 days reversed the effect of central leptin on hypothalamic JAK2, pSTAT3, pAkt, and pFOXO1 protein levels, which was concomitant with a pro-inflammatory response in the hypothalamus. ARA also attenuated the effect of central leptin on hepatic glucose and lipid metabolism by reversing the mRNA expression of the genes involved in gluconeogenesis (G6Pase, PEPCK), glucose transportation (GLUT2), lipogenesis (FAS, SCD1), and cholesterol synthesis (HMG-CoA reductase). These results indicate that an increased exposure to central n-6 PUFA induces central cellular leptin resistance with concomitant defective JAK2-STAT3 and PI3K-Akt signaling. PMID:25986657

  5. What is the Relationship between Gestational Age and Docosahexaenoic Acid (DHA) and Arachidonic Acid (ARA) Levels?

    PubMed Central

    Baack, Michelle L; Puumala, Susan E; Messier, Stephen E; Pritchett, Deborah K; Harris, William S

    2015-01-01

    Long chain polyunsaturated fatty acids (LCPUFA) including docosahexaenoic acid (DHA) and arachidonic acid (ARA) are increasingly transferred from mother to fetus late in pregnancy. Infants born before this transfer is complete are at risk for deficiency. This study determines the relationship between gestational age (GA) and circulating LCPUFA levels to better understand the unique needs of premature infants born at various GAs. Whole blood was collected within the first 7 days of life from 60 preterm (≤34 weeks GA) and 30 term infants (≥38 weeks GA) and FA levels were analyzed. Since concurrent intravenous lipid emulsion can skew composition data, blood LCPUFA concentrations were also measured. Levels were compared among groups, and linear regression models were used to examine the association between FA composition and GA. Preterm infants had significantly lower DHA and ARA levels than term peers, and whether assessed as concentrations or compositions, both directly correlated with GA (p<0.0001). Moreover, FA comparisons suggest that premature infants have impaired synthesis of LCPUFAs from precursors and may require preformed DHA and ARA. This study confirms that essential FA status is strongly related to GA, and that those babies born the earliest are at the greatest risk of LCPUFA deficiency. PMID:26205427

  6. Fatty acid remodeling by LPCAT3 enriches arachidonate in phospholipid membranes and regulates triglyceride transport

    PubMed Central

    Hashidate-Yoshida, Tomomi; Harayama, Takeshi; Hishikawa, Daisuke; Morimoto, Ryo; Hamano, Fumie; Tokuoka, Suzumi M; Eto, Miki; Tamura-Nakano, Miwa; Yanobu-Takanashi, Rieko; Mukumoto, Yoshiko; Kiyonari, Hiroshi; Okamura, Tadashi; Kita, Yoshihiro; Shindou, Hideo; Shimizu, Takao

    2015-01-01

    Polyunsaturated fatty acids (PUFAs) in phospholipids affect the physical properties of membranes, but it is unclear which biological processes are influenced by their regulation. For example, the functions of membrane arachidonate that are independent of a precursor role for eicosanoid synthesis remain largely unknown. Here, we show that the lack of lysophosphatidylcholine acyltransferase 3 (LPCAT3) leads to drastic reductions in membrane arachidonate levels, and that LPCAT3-deficient mice are neonatally lethal due to an extensive triacylglycerol (TG) accumulation and dysfunction in enterocytes. We found that high levels of PUFAs in membranes enable TGs to locally cluster in high density, and that this clustering promotes efficient TG transfer. We propose a model of local arachidonate enrichment by LPCAT3 to generate a distinct pool of TG in membranes, which is required for normal directionality of TG transfer and lipoprotein assembly in the liver and enterocytes. DOI: http://dx.doi.org/10.7554/eLife.06328.001 PMID:25898003

  7. Actions of gallic esters on the arachidonic acid metabolism of human polymorphonuclear leukocytes.

    PubMed

    Christow, S; Luther, H; Ludwig, P; Gruner, S; Schewe, T

    1991-04-01

    Gallic esters with a varying chain length of its alcohol moiety produced strong inhibition of the conversion of [1-14C]-arachidonic acid to 5S-hydroxy-6E,8Z,11Z,14Z-eicosatetraenoic acid (5-HETE) by isolated human polymorphonuclear leukocytes. Octyl gallate and decyl gallate were the most powerful inhibitors with a concentration of half-inhibition of about 1 mumol . 1-1. Additionally these compounds caused however at 10 mumol . 1-1 a complete inhibition of the incorporation of arachidonic acid in triacylglycerols and phospholipids which is assumed to be a consequence of the damage to the energy metabolism of the cells. In contrast, the other gallic esters enhance the incorporation of arachidonic acid in the ester lipids in addition to moderate inhibition of the 5-lipoxygenase pathway.

  8. Protein kinase C, arachidonate metabolism, and tracheal smooth muscle - effects of temperature

    SciTech Connect

    Huang, C.; Baraban, J.; Menkes, H.

    1986-03-01

    Cooling causes airway obstruction in asthma. Contractions of airway smooth muscle may be produced through the phosphatidylinositol cycle and the activation of protein kinase C. Protein kinase C can be activated directly with phorbol esters. The authors studied the effects of temperature on responses to phorbol 12,13-diacetate (PDA) in guinea pig tracheal rings bathed in Krebs-Henseleit solution. At 37/sup 0/C, 1 ..mu..M PDA relaxed the tissue (tension fell 0.60 +/- S.E. 0.04 g). At 27/sub 0/C, 1 ..mu..M PDA contracted the tissue (tension rose 0.050 +/- 0.05 g). In comparison, near maximum contractions produced by 4 ..mu..M carbachol were 2.00 +/- 0.09 g at 37/sub 0/C and 1.90 +/- 0.09 g at 27/sup 0/C. Butler-Gralla et al. showed that phorbol esters may stimulate the release of arachidonic acid from cultured cells. In order to determine whether arachidonate metabolites play a role in responses observed in guinea pig trachea, the authors used indomethacin (a cyclooxygenase inhibitor), FPL 55712 (a leukotriene receptor antagonist) and Na arachidonate. At 37/sup 0/C, 3 ..mu..M indomethacin pretreatment abolished relaxationby 1 uM PDA. At 27/sup 0/C, 10 uM FPL 55712 pretreatment abolished contractions by 1 ..mu..M PDA. Like PDA, 1 ..mu..M Na arachidonate produced relaxation at 37/sup 0/C and contraction at 27/sup 0/C. The authors conclude that the effects of PDA at different temperatures parallel the effects of Na arachidonate. These results suggest that the effects of PDA in the guinea pig trachea are related to the release of endogenous arachidonic acid and that the cyclooxygenase pathway predominates at high temperature and the lipoxygenase pathway predominates at low temperature.

  9. Effects of compounds in leaves of Salix matsudana on arachidonic acid metabolism.

    PubMed

    Zheng, Yi-Nan; Zhang, Jing; Han, Li-Kun; Sekiya, Keizo; Kimura, Yoshiyuki; Okuda, Hiromichi

    2005-12-01

    Apigenin 7-O-beta-D-glucopyranuronide (1), luteolin 7-O-beta-D-glucopyranuronide (2), m-hydroxybenzyl beta-D-glucoside (3), and chrysoeriol 7-O-beta-D-glucopyranuronide (4) were isolated for the first time from the leaves of Salix matsudana. Furthermore, the effects of compounds 1, 2 and 3 on arachidonic acid metabolism were studied. These compounds inhibited significantly the production of 12-hydroxy-5, 8, 10, 14-eicosatetraenoic acid (12-HETE). In addition, the aglycon apigenin inhibited not only 12-HETE but also thromboxane B(2) (TXB(2)). The effect of compound (4) on arachidonic acid metabolism is now under investigation. PMID:16327246

  10. Lithium modifies brain arachidonic and docosahexaenoic metabolism in rat lipopolysaccharide model of neuroinflammation.

    PubMed

    Basselin, Mireille; Kim, Hyung-Wook; Chen, Mei; Ma, Kaizong; Rapoport, Stanley I; Murphy, Robert C; Farias, Santiago E

    2010-05-01

    Neuroinflammation, caused by 6 days of intracerebroventricular infusion of a low dose of lipopolysaccharide (LPS; 0.5 ng/h), stimulates brain arachidonic acid (AA) metabolism in rats, but 6 weeks of lithium pretreatment reduces this effect. To further understand this action of lithium, we measured concentrations of eicosanoids and docosanoids generated from AA and docosahexaenoic acid (DHA), respectively, in high-energy microwaved rat brain using LC/MS/MS and two doses of LPS. In rats fed a lithium-free diet, low (0.5 ng/h)- or high (250 ng/h)-dose LPS compared with artificial cerebrospinal fluid increased brain unesterified AA and prostaglandin E(2) concentrations and activities of AA-selective Ca(2+)-dependent cytosolic phospholipase A(2) (cPLA(2))-IV and Ca(2+)-dependent secretory sPLA(2). LiCl feeding prevented these increments. Lithium had a significant main effect by increasing brain concentrations of lipoxygenase-derived AA metabolites, 5- hydroxyeicosatetraenoic acid (HETE), 5-oxo-eicosatetranoic acid, and 17-hydroxy-DHA by 1.8-, 4.3- and 1.9-fold compared with control diet. Lithium also increased 15-HETE in high-dose LPS-infused rats. Ca(2+)-independent iPLA(2)-VI activity and unesterified DHA and docosapentaenoic acid (22:5n-3) concentrations were unaffected by LPS or lithium. This study demonstrates, for the first time, that lithium can increase brain 17-hydroxy-DHA formation, indicating a new and potentially important therapeutic action of lithium.

  11. Induction of renal cytochrome P450 arachidonic acid epoxygenase activity by dietary gamma-linolenic acid.

    PubMed

    Yu, Zhigang; Ng, Valerie Y; Su, Ping; Engler, Marguerite M; Engler, Mary B; Huang, Yong; Lin, Emil; Kroetz, Deanna L

    2006-05-01

    Dietary gamma-linolenic acid (GLA), a omega-6 polyunsaturated fatty acid found in borage oil (BOR), lowers systolic blood pressure in spontaneously hypertensive rats (SHRs). GLA is converted into arachidonic acid (AA) by elongation and desaturation steps. Epoxyeicosatrienoic acids (EETs) and 20-hydroxyeicosatetraenoic acid (20-HETE) are cytochrome P450 (P450)-derived AA eicosanoids with important roles in regulating blood pressure. This study tested the hypothesis that the blood pressure-lowering effect of a GLA-enriched diet involves alteration of P450-catalyzed AA metabolism. Microsomes and RNA were isolated from the renal cortex of male SHRs fed a basal fat-free diet for 5 weeks to which 11% by weight of sesame oil (SES) or BOR was added. There was a 2.6- to 3.5-fold increase in P450 epoxygenase activity in renal microsomes isolated from the BOR-fed SHRs compared with the SES-fed rats. Epoxygenase activity accounted for 58% of the total AA metabolism in the BOR-treated kidney microsomes compared with 33% in the SES-treated rats. More importantly, renal 14,15- and 8,9-EET levels increased 1.6- to 2.5-fold after dietary BOR treatment. The increase in EET formation is consistent with increases in CYP2C23, CYP2C11, and CYP2J protein levels. There were no differences in the level of renal P450 epoxygenase mRNA between the SES- and BOR-treated rats. Enhanced synthesis of the vasodilatory EETs and decreased formation of the vasoconstrictive 20-HETE suggests that changes in P450-mediated AA metabolism may contribute, at least in part, to the blood pressure-lowering effect of a BOR-enriched diet. PMID:16421287

  12. Arachidonic acid-derived signaling lipids and functions in impaired healing

    PubMed Central

    Dhall, Sandeep; Wijesinghe, Dayanjan Shanaka; Karim, Zubair A.; Castro, Anthony; Vemana, Hari Priya; Khasawneh, Fadi T.; Chalfant, Charles E.; Martins-Green, Manuela

    2016-01-01

    Very little is known about lipid function during wound healing, and much less during impaired healing. Such understanding will help identify what roles lipid signaling plays in the development of impaired/chronic wounds. We took a lipidomics approach to study the alterations in lipid profile in the LIGHT−/− mouse model of impaired healing which has characteristics that resemble those of impaired/chronic wounds in humans, including high levels of oxidative stress, excess inflammation, increased extracellular matrix degradation and blood vessels with fibrin cuffs. The latter suggests excess coagulation and potentially increased platelet aggregation. We show here that in these impaired wounds there is an imbalance in the arachidonic acid (AA) derived eicosonoids that mediate or modulate inflammatory reactions and platelet aggregation. In the LIGHT−/− impaired wounds there is a significant increase in enzymatically derived breakdown products of AA. We found that early after injury there was a significant increase in the eicosanoids 11-, 12-, and 15-hydroxyeicosa-tetranoic acid, and the proinflammatory leukotrienes (LTD4 and LTE) and prostaglandins (PGE2 and PGF2α). Some of these eicosanoids also promote platelet aggregation. This led us to examine the levels of other eicosanoids known to be involved in the latter process. We found that thromboxane (TXA2/B2), and prostacyclins 6kPGF1α are elevated shortly after wounding and in some cases during healing. To determine whether they have an impact in platelet aggregation and hemostasis, we tested LIGHT−/− mouse wounds for these two parameters and found that, indeed, platelet aggregation and hemostasis are enhanced in these mice when compared with the control C57BL/6 mice. Understanding lipid signaling in impaired wounds can potentially lead to development of new therapeutics or in using existing nonsteroidal anti-inflammatory agents to help correct the course of healing. PMID:26135854

  13. Role of endoperoxides in arachidonic acid-induced vasoconstriction in the isolated perfused kidney of the rat.

    PubMed Central

    Quilley, J.; McGiff, J. C.; Nasjletti, A.

    1989-01-01

    1. Administration of arachidonic acid caused dose-dependent vasoconstriction in the isolated rat kidney perfused in situ with Krebs-Henseleit solution. 2. Inhibition of cyclo-oxygenase with indomethacin or meclofenamate reduced the renal vasoconstrictor effect of arachidonic acid. 3. The renal vasoconstrictor effect of arachidonic acid was unaffected by CGS-13080 at concentrations that effectively reduced thromboxane A2 (TxA2) synthesis by platelets and the kidney. 4. The endoperoxide/TxA2 receptor antagonist, SQ 29,548, abolished the renal vasoconstrictor effect of arachidonic acid and of U46619, an endoperoxide analogue. In contrast, SQ 29,548 did not affect the renal vasoconstrictor response to angiotensin II, prostaglandin E2 or F2 alpha. 5. These data suggest that the vasoconstrictor effect of arachidonic acid in the isolated kidney of the rat is mediated by its metabolites, including the prostaglandin endoperoxides. PMID:2522332

  14. Lipid Body Organelles within the Parasite Trypanosoma cruzi: A Role for Intracellular Arachidonic Acid Metabolism.

    PubMed

    Toledo, Daniel A M; Roque, Natália R; Teixeira, Lívia; Milán-Garcés, Erix A; Carneiro, Alan B; Almeida, Mariana R; Andrade, Gustavo F S; Martins, Jefferson S; Pinho, Roberto R; Freire-de-Lima, Célio G; Bozza, Patrícia T; D'Avila, Heloisa; Melo, Rossana C N

    2016-01-01

    Most eukaryotic cells contain varying amounts of cytosolic lipidic inclusions termed lipid bodies (LBs) or lipid droplets (LDs). In mammalian cells, such as macrophages, these lipid-rich organelles are formed in response to host-pathogen interaction during infectious diseases and are sites for biosynthesis of arachidonic acid (AA)-derived inflammatory mediators (eicosanoids). Less clear are the functions of LBs in pathogenic lower eukaryotes. In this study, we demonstrated that LBs, visualized by light microscopy with different probes and transmission electron microscopy (TEM), are produced in trypomastigote forms of the parasite Trypanosoma cruzi, the causal agent of Chagas' disease, after both host interaction and exogenous AA stimulation. Quantitative TEM revealed that LBs from amastigotes, the intracellular forms of the parasite, growing in vivo have increased size and electron-density compared to LBs from amastigotes living in vitro. AA-stimulated trypomastigotes released high amounts of prostaglandin E2 (PGE2) and showed PGE2 synthase expression. Raman spectroscopy demonstrated increased unsaturated lipid content and AA incorporation in stimulated parasites. Moreover, both Raman and MALDI mass spectroscopy revealed increased AA content in LBs purified from AA-stimulated parasites compared to LBs from unstimulated group. By using a specific technique for eicosanoid detection, we immunolocalized PGE2 within LBs from AA-stimulated trypomastigotes. Altogether, our findings demonstrate that LBs from the parasite Trypanosoma cruzi are not just lipid storage inclusions but dynamic organelles, able to respond to host interaction and inflammatory events and involved in the AA metabolism. Acting as sources of PGE2, a potent immunomodulatory lipid mediator that inhibits many aspects of innate and adaptive immunity, newly-formed parasite LBs may be implicated with the pathogen survival in its host. PMID:27490663

  15. Lipid Body Organelles within the Parasite Trypanosoma cruzi: A Role for Intracellular Arachidonic Acid Metabolism

    PubMed Central

    Toledo, Daniel A. M.; Roque, Natália R.; Teixeira, Lívia; Milán-Garcés, Erix A.; Carneiro, Alan B.; Almeida, Mariana R.; Andrade, Gustavo F. S.; Martins, Jefferson S.; Pinho, Roberto R.; Freire-de-Lima, Célio G.; Bozza, Patrícia T.; D’Avila, Heloisa

    2016-01-01

    Most eukaryotic cells contain varying amounts of cytosolic lipidic inclusions termed lipid bodies (LBs) or lipid droplets (LDs). In mammalian cells, such as macrophages, these lipid-rich organelles are formed in response to host-pathogen interaction during infectious diseases and are sites for biosynthesis of arachidonic acid (AA)-derived inflammatory mediators (eicosanoids). Less clear are the functions of LBs in pathogenic lower eukaryotes. In this study, we demonstrated that LBs, visualized by light microscopy with different probes and transmission electron microscopy (TEM), are produced in trypomastigote forms of the parasite Trypanosoma cruzi, the causal agent of Chagas’ disease, after both host interaction and exogenous AA stimulation. Quantitative TEM revealed that LBs from amastigotes, the intracellular forms of the parasite, growing in vivo have increased size and electron-density compared to LBs from amastigotes living in vitro. AA-stimulated trypomastigotes released high amounts of prostaglandin E2 (PGE2) and showed PGE2 synthase expression. Raman spectroscopy demonstrated increased unsaturated lipid content and AA incorporation in stimulated parasites. Moreover, both Raman and MALDI mass spectroscopy revealed increased AA content in LBs purified from AA-stimulated parasites compared to LBs from unstimulated group. By using a specific technique for eicosanoid detection, we immunolocalized PGE2 within LBs from AA-stimulated trypomastigotes. Altogether, our findings demonstrate that LBs from the parasite Trypanosoma cruzi are not just lipid storage inclusions but dynamic organelles, able to respond to host interaction and inflammatory events and involved in the AA metabolism. Acting as sources of PGE2, a potent immunomodulatory lipid mediator that inhibits many aspects of innate and adaptive immunity, newly-formed parasite LBs may be implicated with the pathogen survival in its host. PMID:27490663

  16. Identification of an Arachidonic Acid-Producing Bacterium and Description of Kineococcus arachidonicus sp. nov.

    SciTech Connect

    Fliermans, C.B.

    2001-05-15

    The identification of bacterial with the ability to produce polyunsaturated fatty acids as been limited almost exclusively to gram-negative, psychrophilic, marine microorganisms. Here we describe a new gram-type-positive bactgerium, strain SRS30216T, that produces the polyunsaturated fatty acid, arachidonic acid, and is neither psychrophilic nor a marine isolate.

  17. Arachidonic acid-mediated inhibition of a potassium current in the giant neurons of Aplysia

    SciTech Connect

    Carlson, R.O.

    1990-01-01

    Biochemical and electrophysiological approaches were used to investigate the role of arachidonic acid (AA) in the modulation of an inwardly rectifying potassium current (I{sub R}) in the giant neurons of the marine snail, Aplysia californica. Using ({sup 3}H)AA as tracer, the intracellular free AA pool in Aplysia ganglia was found to be in a state of constant and rapid turnover through deacylation and reacylation of phospholipid, primarily phosphatidyl-inositol. This constant turnover was accompanied by a constant release of free AA and eicosanoids into the extracellular medium. The effects of three pharmacological agents were characterized with regard to AA metabolism in Aplysia ganglia. 4-O-tetra-decanoylphorbol 13-acetate (TPA), an activator of protein kinase C, stimulated liberation of AA from phospholipid, and 4-bromophenacylbromide (BPB), an inhibitor of phospholipate A{sub 2}, inhibited this liberation. Indomethacin at 250 {mu}M was found to inhibit uptake of AA, likely through inhibition of acyl-CoA synthetase. These agents were also found to modulate I{sub R} in ways which were consistent with their biological effects: TPA inhibited I{sub R}, and both BPB and indomethacin stimulated I{sub R} . Modulation of I{sub R} by these substances was found not to involve cAMP metabolism. Acute application of exogenous AA did not affect I{sub R}; however, I{sub R} in giant neurons was found to be inhibited after dialysis with AA or other unsaturated fatty acids. Also, after perfusion with BSA overnight, a treatment which strips the giant neurons of AA in lipid storage, I{sub R} was found to have increased over 2-fold. This perfusion-induced increase was inhibited by the presence of AA or by pretreatment of the giant neurons with BPB. These results suggest AA, provided through constant turnover from phospholipid, mediates constitutive inhibition of I{sub R}.

  18. Acid rain: effects on arachidonic acid metabolism in perfused and ventilated guinea-pig lung.

    PubMed

    Preziosi, P; Ciabattoni, G

    1987-11-01

    Isolated, perfused and ventilated guinea-pig lungs were exposed for 10 min to acid (sulphuric + nitric acid) aerosol mimicking acid rain at pH 4.5 or 2.5, as well as to a control distilled water aerosol (pH 6.0-6.5). Lung perfusing solution was recovered and thromboxane (TX) B2 and leukotriene (LT) B4 were measured by radioimmunoassay (RIA) techniques. In a series of experiments TXB2 release averaged 0.43 +/- 0.18 (+/- SD) ng/min during exposure to distilled water aerosol and increased to 0.70 +/- 0.30 ng/min during exposure to acid aerosol at pH 4.5 (P less than 0.05). In a second series of experiments TXB2 release was 0.46 +/- 0.18 ng/min and increased to 1.07 +/- 0.51 ng/min (P less than 0.01) after acid aerosol at pH 2.5. In both cases LTB4 release, reflecting lipoxygenase activity, was unchanged. LTC4 levels were not measurable under basal conditions as well as after exposure to acid aerosol. A pneumoconstriction was also observed, being more pronounced after acid aerosol at pH 2.5. Individual sulphuric and nitric acid aerosol component solutions at pH 2.5 evoked TXB2 and airway resistance changes corresponding to those observed with the mixed acid aerosol. LTB4 was not modified. Acid rain inhalation may directly stimulate pathways leading to the bronchoconstrictor and pro-aggregating TXA2 synthesis in isolated guinea-pig lung, without affecting the lipoxygenase pathway of arachidonic acid metabolism.

  19. Effect of Arachidonic Acid-enriched Oil Diet Supplementation on the Taste of Broiler Meat

    PubMed Central

    Takahashi, H.; Rikimaru, K.; Kiyohara, R.; Yamaguchi, S.

    2012-01-01

    To elucidate the relationship between the arachidonic acid (AA) content and the taste of broiler meat, the effects of AA-enriched oil (AAO) supplements on the fatty acid content and sensory perceptions of thigh meat were evaluated. Four types of oil, including corn oil (CO), a 1:1 mixture of AAO and palm oil (PO) (1/2 AAO), a 1:3 mixture of AAO and PO (1/4 AAO), and a 1:7 mixture of AAO and PO (1/8 AAO) were prepared. Each type of oil was mixed with silicate at a ratio of 7:3, and added to the diet at a final proportion of 5% of fresh matter. Broiler chickens were fed these diets for 1 wk before slaughter. In thigh meat, the AA content of the 1/2 and 1/4 AAO groups was significantly higher than that of the CO group. The AA content in thigh meat (y, mg/g) increased linearly with increasing dietary AAO content (x, g/100 g of diet), according to the equation y = 0.5674+0.4596× (r2 = 0.8454). The content of other fatty acids was not significantly different among the 4 diet groups. Sensory evaluation showed that the flavor intensity, umami (L-glutamate taste), kokumi (continuity, mouthfulness, and thickness), and aftertaste of the 1/2 and 1/4 AAO groups were significantly higher than that of the CO group. There were significant positive correlations between AA content in thigh meat and the flavor intensity, total taste intensity, umami, and aftertaste. These data suggest that the taste of broiler meat can be improved by the amount of dietary AA supplementation. PMID:25049636

  20. A New Model to Study the Role of Arachidonic Acid in Colon Cancer Pathophysiology.

    PubMed

    Fan, Yang-Yi; Callaway, Evelyn; M Monk, Jennifer; S Goldsby, Jennifer; Yang, Peiying; Vincent, Logan; S Chapkin, Robert

    2016-09-01

    A significant increase in cyclooxygenase 2 (COX2) gene expression has been shown to promote cylcooxygenase-dependent colon cancer development. Controversy associated with the role of COX2 inhibitors indicates that additional work is needed to elucidate the effects of arachidonic acid (AA)-derived (cyclooxygenase and lipoxygenase) eicosanoids in cancer initiation, progression, and metastasis. We have recently developed a novel Fads1 knockout mouse model that allows for the investigation of AA-dependent eicosanoid deficiency without the complication of essential fatty acid deficiency. Interestingly, the survival rate of Fads1-null mice is severely compromised after 2 months on a semi-purified AA-free diet, which precludes long-term chemoprevention studies. Therefore, in this study, dietary AA levels were titrated to determine the minimal level required for survival, while maintaining a distinct AA-deficient phenotype. Null mice supplemented with AA (0.1%, 0.4%, 0.6%, 2.0%, w/w) in the diet exhibited a dose-dependent increase (P < 0.05) in AA, PGE2, 6-keto PGF1α, TXB2, and EdU-positive proliferative cells in the colon. In subsequent experiments, null mice supplemented with 0.6% AA diet were injected with a colon-specific carcinogen (azoxymethane) in order to assess cancer susceptibility. Null mice exhibited significantly (P < 0.05) reduced levels/multiplicity of aberrant crypt foci (ACF) as compared with wild-type sibling littermate control mice. These data indicate that (i) basal/minimal dietary AA supplementation (0.6%) expands the utility of the Fads1-null mouse model for long-term cancer prevention studies and (ii) that AA content in the colonic epithelium modulates colon cancer risk. Cancer Prev Res; 9(9); 750-7. ©2016 AACR. PMID:27339171

  1. Vascular permeabilization by intravenous arachidonate in the rat peritoneal cavity: antagonism by ethamsylate.

    PubMed

    Hannaert, Patrick; Alvarez-Guerra, Miriam; Hider, Hamida; Chiavaroli, Carlo; Garay, Ricardo P

    2003-04-11

    The hemostatic agent, ethamsylate, inhibits arachidonic acid metabolism by a mechanism independent of cyclooxygenase activity and blocks carrageenan-induced rat paw edema. Here, ethamsylate was investigated for (i) in vivo actions on the free radical-dependent, permeabilizing responses to arachidonic acid and (ii) its antioxidant potential in vitro. Vascular permeability was equated to the extravasation rate of Evans blue from plasma into the rat peritoneal cavity. Antioxidant potential was investigated by classical in vitro tests for superoxide radicals, hydroxyl radicals (OH(.)), and nitric oxide. Intravenous ethamsylate induced a very important and significant reduction of permeability responses to arachidonate, both when given preventively and cumulatively. Thus, (i) ethamsylate significantly reversed arachidonate-induced permeabilization, even at the lowest dose tested (44+/-5% at 10 mg/kg) and (ii) a maximal reversal (about 70%) was reached between 50 and 200 mg/kg ethamsylate. In contrast, ethamsylate (100 mg/kg) was unable to antagonize the vascular permeabilization induced by serotonin (5-HT). In antioxidant assays, ethamsylate showed scavenging properties against hydroxyl radicals generated by the Fenton reaction (H(2)O(2)/Fe(2+)) even at 0.1 microM (-20+/-3%). OH(.) scavenging by ethamsylate reached 42+/-8% at 10 microM and 57+/-7% at 1 mM and was comparable to that of reference compounds (vitamin E, troxerutin, and mannitol). Conversely, ethamsylate was a poor scavenger of superoxide and nitric oxide radicals. In conclusion, intravenous ethamsylate potently antagonized the peritoneal vascular permeabilization induced by arachidonate, an action likely due to its antioxidant properties, particularly against hydroxyl radical. Such a mechanism can explain previous observations that ethamsylate inhibits carrageenan-induced rat paw edema. Whether it also participates in the hemostatic action of ethamsylate deserves further investigation.

  2. High expression of arachidonate 15-lipoxygenase and proinflammatory markers in human ischemic heart tissue

    SciTech Connect

    Magnusson, Lisa U.; Lundqvist, Annika; Asp, Julia; Synnergren, Jane; Johansson, Cecilia Thalen; Palmqvist, Lars; Jeppsson, Anders; Hulten, Lillemor Mattsson

    2012-07-27

    Highlights: Black-Right-Pointing-Pointer We found a 17-fold upregulation of ALOX15 in the ischemic heart. Black-Right-Pointing-Pointer Incubation of human muscle cells in hypoxia showed a 22-fold upregulation of ALOX15. Black-Right-Pointing-Pointer We observed increased levels of proinflammatory markers in ischemic heart tissue. Black-Right-Pointing-Pointer Suggesting a link between ischemia and inflammation in ischemic heart biopsies. -- Abstract: A common feature of the ischemic heart and atherosclerotic plaques is the presence of hypoxia (insufficient levels of oxygen in the tissue). Hypoxia has pronounced effects on almost every aspect of cell physiology, and the nuclear transcription factor hypoxia inducible factor-1{alpha} (HIF-1{alpha}) regulates adaptive responses to low concentrations of oxygen in mammalian cells. In our recent work, we observed that hypoxia increases the proinflammatory enzyme arachidonate 15-lipoxygenase (ALOX15B) in human carotid plaques. ALOX15 has recently been shown to be present in the human myocardium, but the effect of ischemia on its expression has not been investigated. Here we test the hypothesis that ischemia of the heart leads to increased expression of ALOX15, and found an almost 2-fold increase in HIF-1{alpha} mRNA expression and a 17-fold upregulation of ALOX15 mRNA expression in the ischemic heart biopsies from patients undergoing coronary bypass surgery compared with non ischemic heart tissue. To investigate the effect of low oxygen concentration on ALOX15 we incubated human vascular muscle cells in hypoxia and showed that expression of ALOX15 increased 22-fold compared with cells incubated in normoxic conditions. We also observed increased mRNA levels of proinflammatory markers in ischemic heart tissue compared with non-ischemic controls. In summary, we demonstrate increased ALOX15 in human ischemic heart biopsies. Furthermore we demonstrate that hypoxia increases ALOX15 in human muscle cells. Our results yield

  3. Intrauterine, postpartum and adult relationships between arachidonic acid (AA) and docosahexaenoic acid (DHA).

    PubMed

    Kuipers, Remko S; Luxwolda, Martine F; Janneke Dijck-Brouwer, D A; Muskiet, Frits A J

    2011-11-01

    Erythrocyte (RBC) fatty acid compositions from populations with stable dietary habits but large variations in RBC-arachidonic (AA) and RBC-docosahexaenoic acid (DHA) provided us with insight into relationships between DHA and AA. It also enabled us to estimate the maternal RBC-DHA (mRBC-DHA) status that corresponded with no decrease in mRBC-DHA during pregnancy, or in infant (i) RBC-DHA or mRBC-DHA during the first 3 months postpartum (DHA-equilibrium) while exclusively breastfeeding. At delivery, iRBC-AA is uniformly high and independent of mRBC-AA. Infants born to mothers with low RBC-DHA exhibit higher, but infants born to mothers with high RBC-DHA exhibit lower RBC-DHA than their mothers. This switch from 'biomagnification' into 'bioattenuation' occurs at 6g% mRBC-DHA. At 6g%, mRBC-DHA is stable throughout pregnancy, corresponds with postpartum infant DHA-equilibrium of 6 and 0.4g% DHA in mature milk, but results in postpartum depletion of mRBC-DHA to 5g%. Postpartum maternal DHA-equilibrium is reached at 8g% mRBC-DHA, corresponding with 1g% DHA in mature milk and 7g% iRBC-DHA at delivery that increases to 8g% during lactation. This 8g% RBC-DHA concurs with the lowest risks of cardiovascular and psychiatric diseases in adults. RBC-data from 1866 infants, males and (non-)pregnant females indicated AA vs. DHA synergism at low RBC-DHA, but antagonism at high RBC-DHA. These data, together with high intakes of AA and DHA from our Paleolithic diet, suggest that bioattenuation of DHA during pregnancy and postnatal antagonism between AA and DHA are the physiological standard for humans across the life cycle. PMID:21561751

  4. Enhancement of arachidonic acid signaling pathway by nicotinic acid receptor HM74A

    SciTech Connect

    Tang, Yuting . E-mail: ytang@prdus.jnj.com; Zhou, Lubing; Gunnet, Joseph W.; Wines, Pamela G.; Cryan, Ellen V.; Demarest, Keith T.

    2006-06-23

    HM74A is a G protein-coupled receptor for nicotinic acid (niacin), which has been used clinically to treat dyslipidemia for decades. The molecular mechanisms whereby niacin exerts its pleiotropic effects on lipid metabolism remain largely unknown. In addition, the most common side effect in niacin therapy is skin flushing that is caused by prostaglandin release, suggesting that the phospholipase A{sub 2} (PLA{sub 2})/arachidonic acid (AA) pathway is involved. Various eicosanoids have been shown to activate peroxisome-proliferator activated receptors (PPAR) that play a diverse array of roles in lipid metabolism. To further elucidate the potential roles of HM74A in mediating the therapeutic effects and/or side effects of niacin, we sought to explore the signaling events upon HM74A activation. Here we demonstrated that HM74A synergistically enhanced UTP- and bradykinin-mediated AA release in a pertussis toxin-sensitive manner in A431 cells. Activation of HM74A also led to Ca{sup 2+}-mobilization and enhanced bradykinin-promoted Ca{sup 2+}-mobilization through Gi protein. While HM74A increased ERK1/2 activation by the bradykinin receptor, it had no effects on UTP-promoted ERK1/2 activation.Furthermore, UTP- and bradykinin-mediated AA release was significantly decreased in the presence of both MAPK kinase inhibitor PD 098059 and PKC inhibitor GF 109203X. However, the synergistic effects of HM74A were not dramatically affected by co-treatment with both inhibitors, indicating the cross-talk occurred at the receptor level. Finally, stimulation of A431 cells transiently transfected with PPRE-luciferase with AA significantly induced luciferase activity, mimicking the effects of PPAR{gamma} agonist rosiglitazone, suggesting that alteration of AA signaling pathway can regulate gene expression via endogenous PPARs.

  5. Media optimization of Parietochloris incisa for arachidonic acid accumulation in an outdoor vertical tubular photobioreactor.

    PubMed

    Tababa, Hazel Guevarra; Hirabayashi, Seishiro; Inubushi, Kazuyuki

    2012-08-01

    The green alga Parietochloris incisa contains a significant amount of the nutritionally valuable polyunsaturated fatty acid and arachidonic acid (AA) and is being considered for mass cultivation for commercial AA production. This study was primarily aimed to define a practical medium formulation that can be used in commercial mass cultivation that will contribute to a substantial increase in the AA productivity of P. incisa with concomitant reduction of nutritional cost. The effect of nutrient limitation on growth and AA content of this microalga was explored in a batch culture in outdoor conditions using a vertical tubular photobioreactor. The study was conducted in two parts: the first was primarily focused on the effect of different nitrogen concentration on growth and AA content and the second part compares nitrogen deprivation, combination of nitrogen and phosphorus deprivation, and combined overall nutrient limitations at different levels of deprivation under low and high population densities. Since complete nitrogen deprivation hampers lipid and AA accumulation of P. incisa, thus, a critical value of nitrogen supply that will activate AA accumulation must be elucidated under specific growth conditions. Under the present experimental conditions, 0.5 g(-1) sodium nitrate obtained a higher AA productivity and volumetric yield relative to the nitrogen-deprived culture corresponding to 36.32 mg L(-1) day(-1) and 523.19 mg L(-1). The combined nitrogen and phosphorus limitation seemed to enhance AA productivity better than nitrogen deprivation alone. The effect of overall nutrient limitation indicates that acute nutrient deficiency can trigger rapid lipid and AA syntheses. The effect of light as a consequence of culture cell density was also discussed. This study therefore shows that the nutrient cost can be greatly reduced by adjusting the nutrient levels and culture density to induce AA accumulation in P. incisa. PMID:22798718

  6. The contribution of arachidonate 15-lipoxygenase in tissue macrophages to adipose tissue remodeling.

    PubMed

    Kwon, H-J; Kim, S-N; Kim, Y-A; Lee, Y-H

    2016-01-01

    Cellular plasticity in adipose tissue involves adipocyte death, its clearance, and de novo adipogenesis, enabling homeostatic turnover and adaptation to metabolic challenges; however, mechanisms regulating these serial events are not fully understood. The present study investigated the roles of arachidonate 15-lipoxygenase (Alox15) in the clearance of dying adipocytes by adipose tissue macrophages. First, upregulation of Alox15 expression and apoptotic adipocyte death in gonadal white adipose tissue (gWAT) were characterized during adipose tissue remodeling induced by β3-adrenergic receptor stimulation. Next, an in vitro reconstruction of adipose tissue macrophages and apoptotic adipocytes recapitulated adipocyte clearance by macrophages and demonstrated that macrophages co-cultured with apoptotic adipocytes increased the expression of efferocytosis-related genes. Genetic deletion and pharmacological inhibition of Alox15 diminished the levels of adipocyte clearance by macrophages in a co-culture system. Gene expression profiling of macrophages isolated from gWAT of Alox15 knockout (KO) mice demonstrated distinct phenotypes, especially downregulation of genes involved in lipid uptake and metabolism compared to wild-type mice. Finally, in vivo β3-adrenergic stimulation in Alox15 KO mice failed to recruit crown-like structures, a macrophage network clearing dying adipocytes in gWAT. Consequently, in Alox15 KO mice, proliferation/differentiation of adipocyte progenitors and β3-adrenergic remodeling of gWAT were impaired compared to wild-type control mice. Collectively, our data established a pivotal role of Alox15 in the resolution of adipocyte death and in adipose tissue remodeling. PMID:27362803

  7. Absorption and metabolism of orally fed arachidonic and linoleic acid in the rat

    SciTech Connect

    Nilsson, A.; Melin, T. )

    1988-11-01

    ({sup 3}H)arachidonic (({sup 3}H)20:4) and ({sup 14}C)linoleic acid ({sup 14}C)18:2 were fed to rats in Intralipid or cream. Later (30-240 min) the stomach, small intestine, plasma, and liver were analyzed for radioactivity in different lipid classes. ({sup 3}H)20:4 and ({sup 14}C)18:2 were emptied from the stomach and absorbed by the intestine at similar rates. The ({sup 3}H)20:4:({sup 14}C)18:2 ratio of the lipids in the small intestinal wall increased, however, with time. This was due to a higher retention of ({sup 3}H)20:4 than ({sup 14}C)18:2 in intestinal phospholipids. In contrast, more of the ({sup 14}C)18:2 was in triacylglycerol of the small intestine and plasma. The highest {sup 3}H:{sup 14}C ratios were found in phosphatidylethanolamine and phosphatidylinositol. The {sup 3}H:{sup 14}C ratio of intestinal phosphatidylcholine varied with the type of fat vehicle used, being highest in the Intralipid experiments. After feeding Intralipid (30-60 min), significantly more of the plasma ({sup 3}H)20:4 than plasma ({sup 14}C)18:2 was in diacylglycerol, the {sup 3}H:{sup 14}C ratio of which was much higher than that of plasma free fatty acids. ({sup 3}H)20:4 and ({sup 14}C)18:2 of chyle triacylglycerol are thus metabolized differently.

  8. Stimulation of arachidonic acid metabolism in primary cultures of osteoblast-like cells by hormones and drugs

    SciTech Connect

    Feyen, J.H.; van der Wilt, G.; Moonen, P.; Di Bon, A.; Nijweide, P.J.

    1984-12-01

    The effects of parathyroid hormone (PTH), dihydroxycholecalciferol (1,25-(OH)2 D3), thrombin, epidermal growth factor (EGF) and 12-o-tetradecanoylphorbol-13-acetate (PMA) on the biosynthesis and release of arachidonic acid metabolites were studied in primary cultures of osteoblast-like cells isolated from 18-day-old chick embryo calvaria. Cells were labelled with (/sup 14/C)-arachidonic acid for 30 h. The radioactive eicosanoids were extracted from the cell culture media after a further 30 h stimulation period and analysed on a PRP-1 column by HPLC. The radioactive products were characterized by co-elution of (/sup 3/H) standard prostanoids. Osteoblasts showed a basal release of the prostanoids 6-keto-PGF1 alpha, TXB2, PGF2 alpha, PGE2, PGD2 and PGB2, the latter being the most abundant one. Indomethacin (10(-5) M) effectively inhibited the basal release, but not that of an as yet unidentified compound. The release of prostanoids was stimulated by PTH (2 U/ml), thrombin (0.4 NIH/ml), EGF (50 ng/ml) and PMA (25 ng/ml), the latter being by far the most potent one. 1,25-(OH)2D3 was found to slightly inhibit the prostanoid release. These results indicate: (1) primary cultures of osteoblasts synthesize several prostaglandins, thromboxane B2 and one unidentified product. (2) the action on bone of PTH and the various drugs tested may be, at least partly, mediated by an increased prostaglandin production by osteoblasts. Clearly this does not apply to 1,25-(OH)2D3.

  9. Arachidonate and docosahexaenoate added to infant formula influence fatty acid composition and subsequent eicosanoid production in neonatal pigs.

    PubMed

    Huang, M C; Craig-Schmidt, M C

    1996-09-01

    As natural components of human milk, arachdonic and docosahexaenoic acids play important roles in neonatal development; thus, addition of these fatty acids to infant formula has been suggested. This study examined the effects of supplementation of infant formula with microbial sources of either arachidonate or docosahexaenoate or both on accretion of these fatty acids in phospholipids and subsequent modulation of eicosanoid production in neonatal pig lung. One-day-old piglets received for 25 d one of four diets (n = 5): 1) standard diet containing a fat blend similar to that of conventional infant formula, 2) diet containing 0.9 g/100 g of total fatty acids as arachidonate, 3) diet containing 0.7 g/100 g as docosahexaenoate, or 4) a diet containing both 1.0 g/100 g as arachidonate and 0.8 g/100 g as docosahexaenoate. Arachidonate supplementation resulted in 30-60% significantly greater arachidonate in lung phosphatidylethanolamine and phosphatidylcholine. In phosphatidylinositol, however, arachidonate was resistant to dietary manipulation. Accretion of docosahexaenoate in all three phospholipid classes was 2.6- to 4.7-fold greater in docosahexaenoate-supplemented groups than in the standard group. Inclusion of arachidonate in the diet augmented both prostacyclin and thromboxane production by 25 to 35%. Docosahexaenoate supplementation resulted in the least eicosanoid production among the treatments, and significant suppression was observed for thromboxane when supplementation with both fatty acids was compared with supplementation with arachidonate alone. Thus, dietary arachidonic acid and docosahexaenoic acid at concentrations only slightly greater than those found in human milk tended to exercise opposing effects on lung eicosanoid production.

  10. Mitochondrial nitric oxide metabolism during rat heart adaptation to high altitude: effect of sildenafil, L-NAME, and L-arginine treatments.

    PubMed

    Zaobornyj, Tamara; Valdez, Laura B; Iglesias, Darío E; Gasco, Manuel; Gonzales, Gustavo F; Boveris, Alberto

    2009-06-01

    Rats submitted to high altitude (Cerro de Pasco, Perú, 4,340 m, Po(2) = 12.2 kPa) for up to 84 days showed a physiological adaptive response with decreased body weight gain (15%), increased right ventricle weight (100%), and increased hematocrit (40%) compared with sea level animals. These classical parameters of adaptation to high altitude were accompanied by an increase in heart mitochondrial enzymes: complexes I-III activity by 34% and mitochondrial nitric oxide synthase (mtNOS) activity and expression by >75%. The hyperbolic increase for mtNOS activity during adaptation to high altitude was similar to the observed pattern for hematocrit. Hematocrit and mtNOS activity mean values correlated linearly (r(2) = 0.75, P increased such response by 40%, whereas l-arginine treatment (106 mg*kg(-1)*day(-1)) had no effect. Nitric oxide (NO) production by mtNOS accounts for approximately 49% of total cellular NO production in sea level rats and for approximately 54% in rats exposed to high altitude for 84 days. It is concluded that mtNOS is a substantial source of cardiac NO, a factor in the adaptive response to sustained heart hypoxia that is susceptible to be modified by pharmacological treatments.

  11. The Arachidonate 15-Lipoxygenase Enzyme Product 15-HETE Is Present in Heart Tissue from Patients with Ischemic Heart Disease and Enhances Clot Formation

    PubMed Central

    Lundqvist, Annika; Sandstedt, Mikael; Sandstedt, Joakim; Wickelgren, Ruth; Hansson, Göran I.; Jeppsson, Anders; Hultén, Lillemor Mattsson

    2016-01-01

    Ischemic heart disease is a major cause of death and morbidity and the search for novel therapeutic targets is still required. We have previously shown that the enzyme arachidonate 15 lipoxygenase (ALOX15), which catalyzes the conversion of arachidonic acid to 15-hydroxy eicosatetraenoic acid (15-HETE), is highly expressed in ischemic heart tissue, but its role in the pathogenesis of ischemic heart disease is unclear. Here we showed that expression of ALOX15, but not ALOX12 or ALOX15B, was increased in ischemic versus non-ischemic human heart biopsy samples. A similar ALOX expression pattern was found in hypoxic human cardiomyocytes and cardiac endothelial cells. We also showed that levels of 15-HETE were significantly higher in ischemic versus non-ischemic human heart biopsy samples and showed a tendency to increase in serum from the patients with ischemic heart disease. Moreover, hypoxia increased the production of 15-HETE levels from human cardiomyocytes and cardiac endothelial cells. The hypoxia-induced increase in 15-HETE levels from human cardiomyocytes was inhibited by the ALOX15 inhibitor baicalein. Finally, by using intrinsic rotational thromboelastometry, we showed that human whole blood clotted faster in the presence of 15-HETE. In summary, we propose that increased ALOX15 expression in heart tissue under ischemic conditions may lead to increased production of 15-HETE, potentially contributing to thrombosis. PMID:27552229

  12. The Arachidonate 15-Lipoxygenase Enzyme Product 15-HETE Is Present in Heart Tissue from Patients with Ischemic Heart Disease and Enhances Clot Formation.

    PubMed

    Lundqvist, Annika; Sandstedt, Mikael; Sandstedt, Joakim; Wickelgren, Ruth; Hansson, Göran I; Jeppsson, Anders; Hultén, Lillemor Mattsson

    2016-01-01

    Ischemic heart disease is a major cause of death and morbidity and the search for novel therapeutic targets is still required. We have previously shown that the enzyme arachidonate 15 lipoxygenase (ALOX15), which catalyzes the conversion of arachidonic acid to 15-hydroxy eicosatetraenoic acid (15-HETE), is highly expressed in ischemic heart tissue, but its role in the pathogenesis of ischemic heart disease is unclear. Here we showed that expression of ALOX15, but not ALOX12 or ALOX15B, was increased in ischemic versus non-ischemic human heart biopsy samples. A similar ALOX expression pattern was found in hypoxic human cardiomyocytes and cardiac endothelial cells. We also showed that levels of 15-HETE were significantly higher in ischemic versus non-ischemic human heart biopsy samples and showed a tendency to increase in serum from the patients with ischemic heart disease. Moreover, hypoxia increased the production of 15-HETE levels from human cardiomyocytes and cardiac endothelial cells. The hypoxia-induced increase in 15-HETE levels from human cardiomyocytes was inhibited by the ALOX15 inhibitor baicalein. Finally, by using intrinsic rotational thromboelastometry, we showed that human whole blood clotted faster in the presence of 15-HETE. In summary, we propose that increased ALOX15 expression in heart tissue under ischemic conditions may lead to increased production of 15-HETE, potentially contributing to thrombosis.

  13. Fucoidan from Undaria pinnatifida prevents vascular dysfunction through PI3K/Akt/eNOS-dependent mechanisms in the l-NAME-induced hypertensive rat model.

    PubMed

    Li, Xiaofei; Li, Jian; Li, Zhike; Sang, Ying; Niu, Yunhui; Zhang, Qianying; Ding, Hong; Yin, Shanye

    2016-05-18

    Despite major scientific advances in its prevention, treatment and care, hypertension remains a serious condition that might lead to long-term complications such as heart disease and stroke. The great majority of forms of hypertension eventually result from an increased vasomotor tone activity that is regulated by endothelial NOS (eNOS) in vascular endothelium. Here, we examined the effect of fucoidan on eNOS activation in human umbilical vein endothelial cells (HUVECs). We also examined the effects of functional components of Undaria pinnatifida fucoidan on blood pressure and vascular function in eNOS inhibition-induced hypertensive rats in vivo. Our results suggest that fucoidan increased nitric oxide production by activating eNOS and Akt phosphorylation, which could be impaired by Akt or eNOS inhibitors. In the hypertensive rat model, treatment of fucoidan resulted in potent and persistent reduction of high blood pressure (BP) even after drug withdrawal. Our results showed that the mechanisms might involve protection against vascular structure damage, enhanced endothelium-independent vascular function and inhibition of abnormal proliferation of smooth muscle cells, which are mediated by the Akt-eNOS signaling pathway. Moreover, fucoidan treatment reduced the vascular inflammation and oxidative stress control caused by iNOS expression. Together, these results support a putative role of fucoidan in hypertension prevention and treatment.

  14. Arachidonic acid release and prostaglandin synthesis in a macrophage-like cell line exposed to asbestos.

    PubMed

    Brown, R C; Poole, A

    1984-10-01

    A macrophage-like cell line (P388D1) has been treated with asbestos and the release of arachidonic acid and its metabolites has been studied using two methods. In the first monolayer cultures of the cells were labelled with tritiated arachidonic acid and the release of label into the medium was quantified: secondly the synthesis and release of prostaglandins E2 and F2 alpha were followed using radioimmune assay. Crocidolite asbestos caused the greatest release of tritium while the medium from chrysotile-treated cultures contained more of both prostaglandins. Both of the fibrous dusts were significantly more active in both test systems than were the two 'inert' materials--titanium dioxide and milled sample of crocidolite. It is suggested that these phenomena are due to the effect of mineral dusts on phospholipase activity and that differences in this activity are associated with differences in the pathogenicity of various mineral dusts. PMID:6098173

  15. The skeletal muscle arachidonic acid cascade in health and inflammatory disease.

    PubMed

    Korotkova, Marina; Lundberg, Ingrid E

    2014-05-01

    Muscle atrophy and weakness are often observed in patients with chronic inflammatory diseases, and are the major clinical features of the autoimmune myopathies, polymyositis and dermatomyositis. A general understanding of the pathogenesis of muscle atrophy and the impaired muscle function associated with chronic inflammatory diseases has not been clarified. In this context, arachidonic acid metabolites, such as the prostaglandin and leukotriene subfamilies, are of interest because they contribute to immune and nonimmune processes. Accumulating evidence suggests that prostaglandins and leukotrienes are involved in causing muscular pain and inflammation, and also in myogenesis and the repair of muscles. In this Review, we summarize novel findings that implicate prostaglandins and leukotrienes in the muscle atrophy and weakness that occur in inflammatory diseases of the muscles, with a focus on inflammatory myopathies. We discuss the role of the arachidonic acid cascade in skeletal muscle growth and function, and individual metabolites as potential therapeutic targets for the treatment of inflammatory muscle diseases.

  16. Regulation of the arachidonic acid mobilization in macrophages by combustion-derived particles

    PubMed Central

    2011-01-01

    Background Acute exposure to elevated levels of environmental particulate matter (PM) is associated with increasing morbidity and mortality rates. These adverse health effects, e.g. culminating in respiratory and cardiovascular diseases, have been demonstrated by a multitude of epidemiological studies. However, the underlying mechanisms relevant for toxicity are not completely understood. Especially the role of particle-induced reactive oxygen species (ROS), oxidative stress and inflammatory responses is of particular interest. In this in vitro study we examined the influence of particle-generated ROS on signalling pathways leading to activation of the arachidonic acid (AA) cascade. Incinerator fly ash particles (MAF02) were used as a model for real-life combustion-derived particulate matter. As macrophages, besides epithelial cells, are the major targets of particle actions in the lung murine RAW264.7 macrophages and primary human macrophages were investigated. Results The interaction of fly ash particles with macrophages induced both the generation of ROS and as part of the cellular inflammatory responses a dose- and time-dependent increase of free AA, prostaglandin E2/thromboxane B2 (PGE2/TXB2), and 8-isoprostane, a non-enzymatically formed oxidation product of AA. Additionally, increased phosphorylation of the mitogen-activated protein kinases (MAPK) JNK1/2, p38 and ERK1/2 was observed, the latter of which was shown to be involved in MAF02-generated AA mobilization and phosphorylation of the cytosolic phospolipase A2. Using specific inhibitors for the different phospolipase A2 isoforms the MAF02-induced AA liberation was shown to be dependent on the cytosolic phospholipase A2, but not on the secretory and calcium-independent phospholipase A2. The initiation of the AA pathway due to MAF02 particle exposure was demonstrated to depend on the formation of ROS since the presence of the antioxidant N-acetyl-cysteine (NAC) prevented the MAF02-mediated enhancement of

  17. Differential stimulation of luminol-enhanced chemiluminescence (CL) and arachidonic acid metabolism in rat peritoneal neutrophils

    SciTech Connect

    Sturm, R.J.; Adams, L.M.; Cullinan, C.A.; Berkenkopf, J.W.; Weichman, B.M.

    1986-03-05

    Phorbol 12-myristate, 13-acetate (PMA) induced the production of radical oxygen species (ROS) from rat peritoneal neutrophils as assessed by CL. ROS generation occurred in a time- (maximum at 13.5 min) and dose- (concentration range of 1.7-498 nM) related fashion. However, 166 nM PMA did not induce either cyclooxygenase (CO) or lipoxygenase (LPO) product formation by 20 min post-stimulation. Conversely, A23187, at concentrations between 0.1 and 10 ..mu..M, stimulated both pathways of arachidonic acid metabolism, but had little or no effect upon ROS production. When suboptimal concentrations of PMA (5.5 nM) and A23187 (0.1-1 ..mu..M) were coincubated with the neutrophils, a synergistic ROS response was elicited. However, arachidonic acid metabolism in the presence of PMA was unchanged relative to A12187 alone. Nordihydroguaiaretic acid (NDGA) inhibited both PMA-induced CL (IC/sub 50/ = 0.9 ..mu..M) and A23187-induced arachidonic acid metabolism (IC/sub 50/ = 1.7 ..mu..M and 6.0 ..mu..M for LPO and CO, respectively). The mixed LPO-CO inhibitor, BW755C, behaved in a qualitatively similar manner to NDGA, whereas the CO inhibitors, indomethacin, piroxicam and naproxen had no inhibitory effect on ROS generation at concentrations as high as 100 ..mu..M. These results suggest that NDGA and BW755C may inhibit CL and arachidonic acid metabolism by distinct mechanisms in rat neutrophils.

  18. Kinetic isotope effects in the oxidation of arachidonic acid by soybean lipoxygenase-1.

    PubMed

    Jacquot, Cyril; Peng, Sheng; van der Donk, Wilfred A

    2008-11-15

    The reaction of soybean lipoxygenase-1 with linoleic acid has been extensively studied and displays very large kinetic isotope effects. In this work, substrate and solvent kinetic isotope effects as well as the viscosity dependence of the oxidation of arachidonic acid were investigated. The hydrogen atom abstraction step was rate-determining at all temperatures, but was partially masked by a viscosity-dependent step at ambient temperatures. The observed KIEs on k(cat) were large ( approximately 100 at 25 degrees C).

  19. Reduced phospholipase A2 activity is not accompanied by reduced arachidonic acid release.

    PubMed

    Goldberg, H; Maxwell, P; Hack, N; Skorecki, K

    1994-01-14

    Arachidonic acid release in cells highly over expressing cytosolic phospholipase A2 has been attributed to mitogen-activated protein kinase phosphorylation of cytosolic phospholipase A2 on serine-505. To investigate the role of cytosolic phospholipase A2 in cellular physiology, we attempted to inhibit cytosolic phospholipase A2 in the intact cell employing an antisense RNA strategy. Swiss 3T3 cells were stably transfected with an antisense cytosolic phospholipase A2 expression vector. A clone of cells with reduced immunodetectable cytosolic phospholipase A2, compared to a vector transfected cell line, was identified by Western blotting and a corresponding decrease in phospholipase A2 activity was confirmed by enzymatic assay in cell free extracts. However, arachidonic acid release from intact cells in response to agonists was not different between antisense and control cell lines. Thus, arachidonic acid release in intact cells with decreased cytosolic phospholipase A2 activity is likely to be modulated by rate limiting factors that are extrinsic to cytosolic phospholipase A2.

  20. Stimulated arachidonate metabolism during foam cell transformation of mouse peritoneal macrophages with oxidized low density lipoprotein.

    PubMed Central

    Yokode, M; Kita, T; Kikawa, Y; Ogorochi, T; Narumiya, S; Kawai, C

    1988-01-01

    Changes in arachidonate metabolism were examined in mouse peritoneal macrophages incubated with various types of lipoproteins. Oxidized low density lipoprotein (LDL) was incorporated by macrophages and stimulated macrophage prostaglandin E2 (PGE2) and leukotriene C4 syntheses, respectively, 10.8- and 10.7-fold higher than by the control. Production of 6-keto-PGF1 alpha, a stable metabolite of prostacyclin, was also stimulated. No stimulation was found with native LDL, which was minimally incorporated by the cells. Acetylated LDL and beta-migrating very low density lipoprotein (beta-VLDL), though incorporated more efficiently than oxidized LDL, also had no stimulatory effect. When oxidized LDL was separated into the lipoprotein-lipid peroxide complex and free lipid peroxides, most of the stimulatory activity was found in the former fraction, indicating that stimulation of arachidonate metabolism in the cell is associated with uptake of the lipoprotein-lipid peroxide complex. These results suggest that peroxidative modification of LDL could contribute to the progression of atheroma by stimulating arachidonate metabolism during incorporation into macrophages. Images PMID:3125226

  1. Inhibition of arachidonic acid metabolism decreases tumor cell invasion and matrix metalloproteinase expression.

    PubMed

    Koontongkaew, Sittichai; Monthanapisut, Paopanga; Saensuk, Theeranuch

    2010-11-01

    Head and neck cancers are known to synthesize arachidonic acid metabolites. Interfering with arachidonic acid metabolism may inhibit growth and invasiveness of cancer cells. In this study we investigate effects of sulindac (the non-selective COX inhibitor), aspirin (the irreversible, preferential COX-1 inhibitor), NS-398 (the selective COX-2 inhibitor), NDGA (nordihydroguaiaretic acid, the selective LOX inhibitor) and ETYA (5,8,11,14-eicosatetraynoic acid, the COX and LOX inhibitor) on cell viability, MMP-2 and MMP-9 activities, and in vitro invasion of cancer cells derived from primary and metastatic head and neck, and colon cancers. The inhibitors of COX and/or LOX could inhibit cell proliferation, MMP activity and invasion in head and neck and colon cancer cells. However, the inhibitory effect was obviously observed in colon cancer cells. Inhibition of arachidonic acid metabolism caused a decrease in cancer cell motility, which partially explained by the inhibition of MMPs. Therefore, COX and LOX pathways play important roles in head and neck cancer cell growth. PMID:20654727

  2. Factors Affecting the Elicitation of Sesquiterpenoid Phytoalexin Accumulation by Eicosapentaenoic and Arachidonic Acids in Potato 1

    PubMed Central

    Bostock, Richard M.; Laine, Roger A.; Kuć, Joseph A.

    1982-01-01

    Eicosapentaenoic and arachidonic acids in extracts of Phytophthora infestans mycelium were identified as the most active elicitors of sesquiterpenoid phytoalexin accumulation in potato tuber slices. These fatty acids were found free or esterified in all fractions with elicitor activity including cell wall preparations. Yeast lipase released a major portion of eicosapentaenoic and arachidonic acids from lyophilized mycelium. Concentration response curves comparing the elicitor activity of the polyunsaturated fatty acids to a cell-free sonicate of P. infestans mycelium indicated that the elicitor activity of the sonicated mycelium exceeded that which would be obtained by the amount of eicosapentaenoic and arachidonic acids (free and esterified) present in the mycelium. Upon acid hydrolysis of lyophilized mycelium, elicitor activity was obtained only from the fatty acid fraction. However, the fatty acids accounted for only 21% of the activity of the unhydrolyzed mycelium and the residue did not enhance their activity. Centrifugation of the hydrolysate, obtained from lyophilized mycelium treated with 2n NaOH, 1 molarity NaBH4 at 100°C, yielded a supernatant fraction with little or no elicitor activity. Addition of this material to the fatty acids restored the activity to that which was present in the unhydrolyzed mycelium. The results indicate that the elicitor activity of the unsaturated fatty acids is enhanced by heat and base-stable factors in the mycelium. PMID:16662691

  3. Effect of inhibitors of arachidonic acid metabolism on alpha-aminoisobutyric acid transport in human lymphocytes.

    PubMed

    Udey, M C; Parker, C W

    1982-02-01

    The role of arachidonic acid metabolism (or metabolites) in the modulation of alpha-aminoisobutyric acid transport in resting and concanavalin A-stimulated human peripheral blood lymphocytes was evaluated using previously characterized inhibitors of arachidonic acid metabolism. Nordihydroguairetic acid (a nonselective antioxidant), 5,8,11,14-eicosatetraynoic acid (an inhibitor of lipoxygenase and cyclooxygenase activities), indomethacin and acetylsalicylic acid (selective cyclooxygenase inhibitors), and 1-benzylimidazole, Ro-22-3581 and Ro-22-3582 (thromboxane synthetase inhibitors) proved to be potent inhibitors of amino acid transport activity in normal resting and lectin-activated lymphocytes at concentrations known to decrease thromboxane A2 production. The rank order of effectiveness of these various inhibitors compared favorably with their relative potencies as inhibitors of thromboxane B2 synthesis under the same conditions, as determined by radioimmunoassay. Inhibitory effects noted were not due to overt cytotoxicity and seemed to involve changes primarily in the Vmax and not the Km of the transport process. Drug-induced alterations in the magnitude of concanavalin A binding were not observed. These results suggest that the activity of amino acid transport systems can be influenced by certain arachidonic acid metabolites, probably thromboxanes, in both stimulated and unstimulated lymphocytes. In addition, these findings may provide a partial explanation for the observation that inhibitors of thromboxane formation prevent lymphocyte mitogenesis.

  4. Brain thromboxane A2 via arachidonic acid cascade induces the hypothalamic-pituitary-gonadal axis activation in rats.

    PubMed

    Erkan, Leman G; Altinbas, Burcin; Guvenc, Gokcen; Alcay, Selim; Toker, Mehmed Berk; Ustuner, Burcu; Udum Kucuksen, Duygu; Yalcin, Murat

    2015-05-01

    The current study was designed to determine the effect of centrally administrated arachidonic acid (AA) on plasma gonadotropin hormone-releasing hormone (GnRH), follicle stimulating hormone (FSH), luteinizing hormone (LH) and testosterone level, and sperm parameters, and to show the mediation of the central cyclooxygenase (COX) to thromboxane A2 (TXA2) signaling pathway in AA-induced hormonal and sperm parameter effects. Studies were performed in male Sprague-Dawley rats. A total of 150 or 300 μl/5 μl doses of AA were injected intracerebroventricularly (icv). AA significantly caused dose- and time-dependent increases in plasma FSH, LH and testosterone levels of animals, but not plasma GnRH level. AA also significantly increased sperm motility of the rats without change sperm number. Pretreated with ibuprofen, a nonselective COX inhibitor (250 μg/5 μl; icv), and furegrelate, a TXA2 synthesis inhibitor (250 μg/5 μl; icv), prevented AA-evoked increase in plasma FSH, LH and testosterone levels, and sperm motility. In conclusion, our findings show that centrally administered AA increases plasma FSH, LH and testosterone levels and sperm motility of conscious male rats. Moreover, according to our findings, central COX-TXA2 signaling pathway mediates these AA-induced effects.

  5. Ultraviolet B irradiation induces changes in the distribution and release of arachidonic acid, dihomo-gamma-linolenic acid, and eicosapentaenoic acid in human keratinocytes in culture

    SciTech Connect

    Punnonen, K.; Puustinen, T.; Jansen, C.T.

    1987-05-01

    There is increasing evidence that derivatives of 20-carbon polyunsaturated fatty acids, the eicosanoids, play an important role in the inflammatory responses of the human skin. To better understand the metabolic fate of fatty acids in the skin, the effect of ultraviolet B (UVB) irradiation (280-320 nm) on the distribution and release of /sup 14/C-labeled arachidonic acid, dihomo-gamma-linolenic acid, and eicosapentaenoic acid in human keratinocytes in culture was investigated. Ultraviolet B irradiation induced the release of all three /sup 14/C-labeled fatty acids from the phospholipids, especially from phosphatidylethanolamine, and this was accompanied by increased labeling of the nonphosphorus lipids. This finding suggests that UVB induces a significant liberation of eicosanoid precursor fatty acids from cellular phospholipids, but the liberated fatty acids are largely reincorporated into the nonphosphorus lipids. In conclusion, the present study suggests that not only arachidonic acid but also dihomo-gamma-linolenic acid, and eicosapentaenoic acid might be involved in the UVB irradiation-induced inflammatory reactions of human skin.

  6. The effects of centrally injected arachidonic acid on respiratory system: Involvement of cyclooxygenase to thromboxane signaling pathway.

    PubMed

    Erkan, Leman Gizem; Guvenc, Gokcen; Altinbas, Burcin; Niaz, Nasir; Yalcin, Murat

    2016-05-01

    Arachidonic acid (AA) is a polyunsaturated fatty acid that is present in the phospholipids of the cell membranes of the body and is abundant in the brain. Exogenously administered AA has been shown to affect brain metabolism and to exhibit cardiovascular and neuroendocrine actions. However, little is known regarding its respiratory actions and/or central mechanism of its respiratory effects. Therefore, the present study was designed to investigate the possible effects of centrally injected AA on respiratory system and the mediation of the central cyclooxygenase (COX) to thromboxane A2 (TXA2) signaling pathway on AA-induced respiratory effects in anaesthetized rats. Intracerebroventricular (i.c.v.) administration of AA induced dose- and time-dependent increase in tidal volume, respiratory rates and respiratory minute ventilation and also caused an increase in partial oxygen pressure (pO2) and decrease in partial carbon dioxide pressure (pCO2) in male anaesthetized Spraque Dawley rats. I.c.v. pretreatment with ibuprofen, a non-selective COX inhibitor, completely blocked the hyperventilation and blood gases changes induced by AA. In addition, central pretreatment with different doses of furegrelate, a TXA2 synthesis inhibitor, also partially prevented AA-evoked hyperventilation and blood gases effects. These data explicitly show that centrally administered AA induces hyperventilation with increasing pO2 and decreasing pCO2 levels which are mediated by the activation of central COX to TXA2 signaling pathway.

  7. Diffusion of intracerebrally injected (1-/sup 14/C)arachidonic acid and (2-/sup 3/H)glycerol in the mouse brain. Effects of ischemia and electroconvulsive shock

    SciTech Connect

    Pediconi, M.F.; Rodriguez de Turco, E.B.; Bazan, N.G.

    1982-12-01

    (2-/sup 3/H)Glycerol and (1-/sup 14/C)arachidonic acid were injected into the region of the frontal horn of the left ventricle of mice and were distributed rapidly throughout the brain. After 10 sec, most of the radioactive fatty acid was found in the hemisphere near the injection site; after 10 min, it was recovered in similar proportions in the cerebellum and brain stem. (2-/sup 3/H)Glycerol showed a heterogeneous distribution, with most of the label remaining in the left hemisphere even after 10 min. On a fresh weight basis, cerebrum, cerebellum, and brain stem were found to contain similar amounts of labeled glycerol. However, the amount of (1-/sup 14/C)arachidonate in cerebrum was only 50% of that recovered from cerebellum or brain stem. Brain ischemia or a single electroconvulsive shock reduced the spread of the label, producing an accumulation of radioactivity in the injected hemisphere, except for an increase in (2-/sup 3/H)glycerol in the brain stem during ischemia. Despite the significant decrease in available precursor in the cerebellum and brain stem after electroshock, the amount of label incorporated into lipids was not altered in these areas and only slightly diminished in the cerebrum.

  8. Arachidonic Acid and Eicosapentaenoic Acid Metabolism in Juvenile Atlantic Salmon as Affected by Water Temperature.

    PubMed

    Norambuena, Fernando; Morais, Sofia; Emery, James A; Turchini, Giovanni M

    2015-01-01

    Salmons raised in aquaculture farms around the world are increasingly subjected to sub-optimal environmental conditions, such as high water temperatures during summer seasons. Aerobic scope increases and lipid metabolism changes are known plasticity responses of fish for a better acclimation to high water temperature. The present study aimed at investigating the effect of high water temperature on the regulation of fatty acid metabolism in juvenile Atlantic salmon fed different dietary ARA/EPA ratios (arachidonic acid, 20:4n-6/ eicosapentaenoic acid, 20:5n-3), with particular focus on apparent in vivo enzyme activities and gene expression of lipid metabolism pathways. Three experimental diets were formulated to be identical, except for the ratio EPA/ARA, and fed to triplicate groups of Atlantic salmon (Salmo salar) kept either at 10°C or 20°C. Results showed that fatty acid metabolic utilisation, and likely also their dietary requirements for optimal performance, can be affected by changes in their relative levels and by environmental temperature in Atlantic salmon. Thus, the increase in temperature, independently from dietary treatment, had a significant effect on the β-oxidation of a fatty acid including EPA, as observed by the apparent in vivo enzyme activity and mRNA expression of pparα -transcription factor in lipid metabolism, including β-oxidation genes- and cpt1 -key enzyme responsible for the movement of LC-PUFA from the cytosol into the mitochondria for β-oxidation-, were both increased at the higher water temperature. An interesting interaction was observed in the transcription and in vivo enzyme activity of Δ5fad-time-limiting enzyme in the biosynthesis pathway of EPA and ARA. Such, at lower temperature, the highest mRNA expression and enzyme activity was recorded in fish with limited supply of dietary EPA, whereas at higher temperature these were recorded in fish with limited ARA supply. In consideration that fish at higher water temperature

  9. Arachidonic Acid and Eicosapentaenoic Acid Metabolism in Juvenile Atlantic Salmon as Affected by Water Temperature

    PubMed Central

    Norambuena, Fernando; Morais, Sofia; Emery, James A.; Turchini, Giovanni M.

    2015-01-01

    Salmons raised in aquaculture farms around the world are increasingly subjected to sub-optimal environmental conditions, such as high water temperatures during summer seasons. Aerobic scope increases and lipid metabolism changes are known plasticity responses of fish for a better acclimation to high water temperature. The present study aimed at investigating the effect of high water temperature on the regulation of fatty acid metabolism in juvenile Atlantic salmon fed different dietary ARA/EPA ratios (arachidonic acid, 20:4n-6/ eicosapentaenoic acid, 20:5n-3), with particular focus on apparent in vivo enzyme activities and gene expression of lipid metabolism pathways. Three experimental diets were formulated to be identical, except for the ratio EPA/ARA, and fed to triplicate groups of Atlantic salmon (Salmo salar) kept either at 10°C or 20°C. Results showed that fatty acid metabolic utilisation, and likely also their dietary requirements for optimal performance, can be affected by changes in their relative levels and by environmental temperature in Atlantic salmon. Thus, the increase in temperature, independently from dietary treatment, had a significant effect on the β-oxidation of a fatty acid including EPA, as observed by the apparent in vivo enzyme activity and mRNA expression of pparα -transcription factor in lipid metabolism, including β-oxidation genes- and cpt1 -key enzyme responsible for the movement of LC-PUFA from the cytosol into the mitochondria for β-oxidation-, were both increased at the higher water temperature. An interesting interaction was observed in the transcription and in vivo enzyme activity of Δ5fad–time-limiting enzyme in the biosynthesis pathway of EPA and ARA. Such, at lower temperature, the highest mRNA expression and enzyme activity was recorded in fish with limited supply of dietary EPA, whereas at higher temperature these were recorded in fish with limited ARA supply. In consideration that fish at higher water temperature

  10. Nitro-Arachidonic Acid Prevents Angiotensin II-Induced Mitochondrial Dysfunction in a Cell Line of Kidney Proximal Tubular Cells.

    PubMed

    Sánchez-Calvo, Beatriz; Cassina, Adriana; Rios, Natalia; Peluffo, Gonzalo; Boggia, José; Radi, Rafael; Rubbo, Homero; Trostchansky, Andres

    2016-01-01

    Nitro-arachidonic acid (NO2-AA) is a cell signaling nitroalkene that exerts anti-inflammatory activities during macrophage activation. While angiotensin II (ANG II) produces an increase in reactive oxygen species (ROS) production and mitochondrial dysfunction in renal tubular cells, little is known regarding the potential protective effects of NO2-AA in ANG II-mediated kidney injury. As such, this study examines the impact of NO2-AA on ANG II-induced mitochondrial dysfunction in an immortalized renal proximal tubule cell line (HK-2 cells). Treatment of HK-2 cells with ANG II increases the production of superoxide (O2●-), nitric oxide (●NO), inducible nitric oxide synthase (NOS2) expression, peroxynitrite (ONOO-) and mitochondrial dysfunction. Using high-resolution respirometry, it was observed that the presence of NO2-AA prevented ANG II-mediated mitochondrial dysfunction. Attempting to address mechanism, we treated isolated rat kidney mitochondria with ONOO-, a key mediator of ANG II-induced mitochondrial damage, in the presence or absence of NO2-AA. Whereas the activity of succinate dehydrogenase (SDH) and ATP synthase (ATPase) were diminished upon exposure to ONOO-, they were restored by pre-incubating the mitochondria with NO2-AA. Moreover, NO2-AA prevents oxidation and nitration of mitochondrial proteins. Combined, these data demonstrate that ANG II-mediated oxidative damage and mitochondrial dysfunction is abrogated by NO2-AA, identifying this compound as a promising pharmacological tool to prevent ANG II-induced renal disease. PMID:26943326

  11. The effect of antibiotic exposure on eicosanoid generation from arachidonic acid and gene expression in a primitive chordate, Branchiostoma belcheri

    PubMed Central

    Yuan, Dongjuan; Pan, Minming; Zou, Qiuqiong; Chen, Chengyong; Chen, Shangwu; Xu, Anlong

    2015-01-01

    Chloramphenicol (Chl) is an effective antimicrobial agent widely used in veterinary medicine and commonly used in fish. Its use is restricted in the clinic because of adverse effects on the immune system and oxidative stress in mammals. However, the effects of Chl treatment on invertebrates remain unclear. Amphioxus, a basal chordate, is an ideal model to study the origin and evolution of the vertebrate immune system as it has a primary vertebrate-like arachidonic acid (AA) metabolic system. Here, we combined transcriptomic and lipidomic approaches to investigate the immune system and observe the oxygenated metabolites of AA to address the antibiotic effects on amphioxus. Tissue necrosis of the gill slits occurred in the Chl-treated amphioxus, but fewer epithelial cells were lost when treated with both Chl and ampicillin (Amp). The immune related pathways were dysregulated in both of the antibiotic treatment groups. The Chl alone treatment resulted in immunosuppression with down-regulation of the innate immune genes. In contrast, the Chl + Amp treatment resulted in immunostimulation to some extent, as shown by KEGG clustering. Furthermore, Chl induced a 3-fold reduction in the level of the eicosanoids, while the Chl + Amp treatment resulted in 1.7-fold increase of eicosanoid level. Thus in amphioxus, Amp might relieve the effects of the Chl-induced immune suppression and increase the level of eicosanoids from AA. Finally, the oxygenated metabolites from AA might be crucial to evaluate the effects of Chl treatment in animals. PMID:26288743

  12. Nitro-Arachidonic Acid Prevents Angiotensin II-Induced Mitochondrial Dysfunction in a Cell Line of Kidney Proximal Tubular Cells

    PubMed Central

    Sánchez-Calvo, Beatriz; Cassina, Adriana; Rios, Natalia; Boggia, José; Radi, Rafael; Rubbo, Homero; Trostchansky, Andres

    2016-01-01

    Nitro-arachidonic acid (NO2-AA) is a cell signaling nitroalkene that exerts anti-inflammatory activities during macrophage activation. While angiotensin II (ANG II) produces an increase in reactive oxygen species (ROS) production and mitochondrial dysfunction in renal tubular cells, little is known regarding the potential protective effects of NO2-AA in ANG II-mediated kidney injury. As such, this study examines the impact of NO2-AA on ANG II-induced mitochondrial dysfunction in an immortalized renal proximal tubule cell line (HK-2 cells). Treatment of HK-2 cells with ANG II increases the production of superoxide (O2●-), nitric oxide (●NO), inducible nitric oxide synthase (NOS2) expression, peroxynitrite (ONOO-) and mitochondrial dysfunction. Using high-resolution respirometry, it was observed that the presence of NO2-AA prevented ANG II-mediated mitochondrial dysfunction. Attempting to address mechanism, we treated isolated rat kidney mitochondria with ONOO-, a key mediator of ANG II-induced mitochondrial damage, in the presence or absence of NO2-AA. Whereas the activity of succinate dehydrogenase (SDH) and ATP synthase (ATPase) were diminished upon exposure to ONOO-, they were restored by pre-incubating the mitochondria with NO2-AA. Moreover, NO2-AA prevents oxidation and nitration of mitochondrial proteins. Combined, these data demonstrate that ANG II-mediated oxidative damage and mitochondrial dysfunction is abrogated by NO2-AA, identifying this compound as a promising pharmacological tool to prevent ANG II–induced renal disease. PMID:26943326

  13. Heating of vegetable oils influences the activity of enzymes participating in arachidonic acid formation in Wistar rats.

    PubMed

    Stawarska, Agnieszka; Białek, Agnieszka; Tokarz, Andrzej

    2015-10-01

    Dietary intake of lipids and their fatty acids profile influence many aspects of health. Thermal processing changes the properties of edible oils and can also modify their metabolism, for example, eicosanoids formation. The aim of our study was to verify whether the activity of desaturases can be modified by lipids intake, especially by the fatty acids content. The experimental diets contained rapeseed oil, sunflower oil, and olive oil, both unheated and heated (for 10 minutes at 200 °C each time before administration), and influenced the fatty acids composition in serum and the activity of enzymes participating in arachidonic acid (AA) formation. The activity of desaturases was determined by measuring the amounts of AA formed in vitro derived from linoleic acid as determined in liver microsomes of Wistar rats. In addition, the indices of ∆(6)-desaturase (D6D) and ∆(5)-desaturase (D5D) have been determined. To realize this aim, the method of high-performance liquid chromatography has been used with ultraviolet-visible spectrophotometry detection. Diet supplementation with the oils rich in polyunsaturated fatty acids affects the fatty acids profile in blood serum and the activity of D6D and ∆(5)-desaturase in rat liver microsomes, the above activities being dependent on the kind of oil applied. Diet supplementation with heated oils has been found to increase the amount of AA produced in hepatic microsomes; and in the case of rapeseed oil and sunflower oil, it has also increased D6D activity.

  14. Fatty acid transfer in the food web of a coastal Mediterranean lagoon: Evidence for high arachidonic acid retention in fish

    NASA Astrophysics Data System (ADS)

    Koussoroplis, Apostolos-Manuel; Bec, Alexandre; Perga, Marie-Elodie; Koutrakis, Emmanuil; Bourdier, Gilles; Desvilettes, Christian

    2011-02-01

    The transfer of fatty acids (FAs) in the food web of a Mediterranean lagoon was studied using FA compositional patterns across several trophic levels. The structure of the food web was inferred from C and N stable isotopes values and an isotope mixing model was used in order to estimate the relative contribution of the different potential food sources to the biomass of consumers. Bidimensional plots of FA composition of food web components against their δ 15N values indicated a general trend of increasing proportions of highly unsaturated fatty acids (HUFAs) with increasing trophic levels while the proportions of saturated fatty acids (SAFAs) and 18-carbon polyunsaturated fatty acids (PUFAs) decreased. Using the relative contributions of food sources to consumers and their FA compositions, a model was built in order to estimate the PUFA composition of consumer mixed diets which was compared to consumer PUFA profiles. The latter allowed the identification of the PUFAs which were mostly enriched/retained in consumer lipids. There was a surprisingly high retention of arachidonic acid (ARA), a trend which challenges the idea of low ARA needs in marine fish and suggests the important physiological role of this essential FA for fish in estuarine environments.

  15. The effect of antibiotic exposure on eicosanoid generation from arachidonic acid and gene expression in a primitive chordate, Branchiostoma belcheri.

    PubMed

    Yuan, Dongjuan; Pan, Minming; Zou, Qiuqiong; Chen, Chengyong; Chen, Shangwu; Xu, Anlong

    2015-01-01

    Chloramphenicol (Chl) is an effective antimicrobial agent widely used in veterinary medicine and commonly used in fish. Its use is restricted in the clinic because of adverse effects on the immune system and oxidative stress in mammals. However, the effects of Chl treatment on invertebrates remain unclear. Amphioxus, a basal chordate, is an ideal model to study the origin and evolution of the vertebrate immune system as it has a primary vertebrate-like arachidonic acid (AA) metabolic system. Here, we combined transcriptomic and lipidomic approaches to investigate the immune system and observe the oxygenated metabolites of AA to address the antibiotic effects on amphioxus. Tissue necrosis of the gill slits occurred in the Chl-treated amphioxus, but fewer epithelial cells were lost when treated with both Chl and ampicillin (Amp). The immune related pathways were dysregulated in both of the antibiotic treatment groups. The Chl alone treatment resulted in immunosuppression with down-regulation of the innate immune genes. In contrast, the Chl + Amp treatment resulted in immunostimulation to some extent, as shown by KEGG clustering. Furthermore, Chl induced a 3-fold reduction in the level of the eicosanoids, while the Chl + Amp treatment resulted in 1.7-fold increase of eicosanoid level. Thus in amphioxus, Amp might relieve the effects of the Chl-induced immune suppression and increase the level of eicosanoids from AA. Finally, the oxygenated metabolites from AA might be crucial to evaluate the effects of Chl treatment in animals.

  16. Arachidonic acid-dependent carbon-eight volatile synthesis from wounded liverwort (Marchantia polymorpha).

    PubMed

    Kihara, Hirotomo; Tanaka, Maya; Yamato, Katsuyuki T; Horibata, Akira; Yamada, Atsushi; Kita, Sayaka; Ishizaki, Kimitsune; Kajikawa, Masataka; Fukuzawa, Hideya; Kohchi, Takayuki; Akakabe, Yoshihiko; Matsui, Kenji

    2014-11-01

    Eight-carbon (C8) volatiles, such as 1-octen-3-ol, octan-3-one, and octan-3-ol, are ubiquitously found among fungi and bryophytes. In this study, it was found that the thalli of the common liverwort Marchantia polymorpha, a model plant species, emitted high amounts of C8 volatiles mainly consisting of (R)-1-octen-3-ol and octan-3-one upon mechanical wounding. The induction of emission took place within 40min. In intact thalli, 1-octen-3-yl acetate was the predominant C8 volatile while tissue disruption resulted in conversion of the acetate to 1-octen-3-ol. This conversion was carried out by an esterase showing stereospecificity to (R)-1-octen-3-yl acetate. From the transgenic line of M. polymorpha (des6(KO)) lacking arachidonic acid and eicosapentaenoic acid, formation of C8 volatiles was only minimally observed, which indicated that arachidonic and/or eicosapentaenoic acids were essential to form C8 volatiles in M. polymorpha. When des6(KO) thalli were exposed to the vapor of 1-octen-3-ol, they absorbed the alcohol and converted it into 1-octen-3-yl acetate and octan-3-one. Therefore, this implied that 1-octen-3-ol was the primary C8 product formed from arachidonic acid, and further metabolism involving acetylation and oxidoreduction occurred to diversify the C8 products. Octan-3-one was only minimally formed from completely disrupted thalli, while it was formed as the most abundant product in partially disrupted thalli. Therefore, it is assumed that the remaining intact tissues were involved in the conversion of 1-octen-3-ol to octan-3-one in the partially disrupted thalli. The conversion was partly promoted by addition of NAD(P)H into the completely disrupted tissues, suggesting an NAD(P)H-dependent oxidoreductase was involved in the conversion. PMID:25174554

  17. UVB irradiation and distribution of arachidonic acid (20:4) and stearic acid (18:0) in human keratinocytes.

    PubMed

    Punnonen, K; Jansén, C T

    1989-04-01

    Human keratinocytes (NCTC 2544) in culture were labeled with either 14C-arachidonic acid or 14C-stearic acid and then exposed to UVB irradiation (9 or 90 mJ/cm2). Exposure of the keratinocytes to UVB irradiation resulted in considerable rearrangement of the membrane fatty acids. Following UVB irradiation the percentage amounts of 14C-arachidonic acid and 14C-stearic acid were significantly decreased in phospholipids, in phosphatidylethanolamine and in phosphatidylcholine. The liberation of stearic acid from phospholipids was accompanied by accumulation of radiolabel into the culture medium, but in 14C-arachidonic acid-labeled cells the amount of radiolabel in the culture medium was not changed following UVB irradiation despite liberation of arachidonic acid from phospholipids. It seems evident that, following UVB irradiation, the rate of reincorporation of liberated 14C-arachidonic acid, a polyunsaturated fatty acid, is higher and thus different from that of a saturated fatty acid, 14C-stearic acid. The present study suggests that exposure of keratinocytes to UVB irradiation is followed by liberation of both saturated and unsaturated fatty acids and also considerable reacylation of the unsaturated fatty acids.

  18. Vibrational structure of the polyunsaturated fatty acids eicosapentaenoic acid and arachidonic acid studied by infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Kiefer, Johannes; Noack, Kristina; Bartelmess, Juergen; Walter, Christian; Dörnenburg, Heike; Leipertz, Alfred

    2010-02-01

    The spectroscopic discrimination of the two structurally similar polyunsaturated C 20 fatty acids (PUFAs) 5,8,11,14,17-eicosapentaenoic acid and 5,8,11,14-eicosatetraenoic acid (arachidonic acid) is shown. For this purpose their vibrational structures are studied by means of attenuated total reflection (ATR) Fourier-transform infrared (FT-IR) spectroscopy. The fingerprint regions of the recorded spectra are found to be almost identical, while the C-H stretching mode regions around 3000 cm -1 show such significant differences as results of electronic and molecular structure alterations based on the different degree of saturation that both fatty acids can be clearly distinguished from each other.

  19. Production of arachidonic and linoleic acid metabolites by guinea pig tracheal epithelial cells

    SciTech Connect

    Oosthuizen, M.J.; Engels, F.; Van Esch, B.; Henricks, P.A.; Nijkamp, F.P. )

    1990-08-01

    Pulmonary epithelial cells may be responsible for regulating airway smooth muscle function, in part by release of fatty acid-derived mediators. Incubation of isolated guinea pig tracheal epithelial cells with radiolabeled arachidonic acid (AA) leads to the production of 5- and 15-hydroxyeicosatetraenoic acid (5- and 15-HETE) and smaller amounts of leukotriene (LT) B4 and C4 and 12-hydroxyheptadecatrienoic acid (HHT). Epithelial cells also are able to release linoleic acid (LA) metabolites. Incubation with radiolabeled linoleic acid leads to the formation of 9- and 13-hydroxyoctadecadienoic acid (9- and 13-HODE). The biological significance of these mediators produced by epithelial cells is discussed.

  20. The effects of the oral administration of fish oil concentrate on the release and the metabolism of (/sup 14/C)arachidonic acid and (/sup 14/C)eicosapentaenoic acid by human platelets

    SciTech Connect

    Hirai, A.; Terano, T.; Hamazaki, T.; Sajiki, J.; Kondo, S.; Ozawa, A.; Fujita, T.; Miyamoto, T.; Tamura, Y.; Kumagai, A.

    1982-11-01

    It has been suggested by several investigators that eicosapentaenoic acid (C20:5 omega 3, EPA) might have anti-thrombotic effects. In this experiment, the effect of the oral administration of EPA rich fish oil concentrate on platelet aggregation and the release and the metabolism of (/sup 1 -14/C)arachidonic acid and ((U)-/sup 14/C)eicosapentaenoic acid by human platelets was studied. Eight healthy male subjects ingested 18 capsules of fish oil concentrate (EPA 1.4 g) per day for 4 weeks. Plasma and platelet concentrations of EPA markedly increased, while those of arachidonic acid (C20:4 omega 6, AA) and docosahexaenoic acid (C22:6 omega 3, DHA) did not change. Platelet aggregation induced by collagen and ADP was reduced. Collagen induced (/sup 14/C)thromboxane B2 (TXB2) formation from (/sup 14/C)AA prelabeled platelets decreased. There was no detectable formation of (/sup 14/C)TXB3 from (/sup 14/C)EPA prelabeled platelets, and the conversion of exogenous (/sup 14/C)EPA to (/sup 14/C)TXB3 was lower than that of (/sup 14/C)AA to (/sup 14/C)TXB2. The release of (/sup 14/C)AA from (/sup 14/C)AA prelabeled platelets by collagen was significantly decreased. These observations raise the possibility that the release of arachidonic acid from platelet lipids might be affected by the alteration of EPA content in platelets.

  1. Relative turnover of (/sup 3/H)arachidonic acid and (/sup 14/C)eicosapentaenoic acid in stimulated human platelets

    SciTech Connect

    Weaver, B.J.; Holub, B.J.

    1986-03-05

    The relative release of arachidonic acid (AA) versus eicosapentaenoic acid (EPA) from platelet phospholipids may be important in accounting for the potential of dietary fish oil containing EPA to alter platelet reactivity. Human platelets enriched in EPA and prelabelled with (/sup 3/H)AA and (/sup 14/C)EPA were used to examine the relative losses of these fatty acids from platelet phospholipids upon stimulation. Washed dual-labelled platelets were incubated with and without thrombin in the presence of BW755C and in the presence and absence of trifluoperazine. The platelet lipids were extracted and the individual phospholipids as well as diacylglycerol (DG), phosphatidic acid (PA), etc. were separated by thin-layer chromatography and the radioactivity in each fraction determined. The (/sup 3/H)AA/(/sup 14/C)EPA dpm ratio for the loss in radioactivity from PC upon thrombin stimulation was similar to that for the PC in resting platelets. This suggests no marked selectivity in the degradation of AA versus EPA species of PC during platelet activation. The (/sup 3/H)/(/sup 14/C) ratios for the increased radioactivity in DG and PA upon thrombin stimulation were slightly higher than the ratio in PI from resting platelets suggesting only a minor preference for 1-acyl 2-arachidonoyl PI over 1-acyl 2-eicosapentaenoyl PI in the pathway from PI to DG to PA.

  2. Purification and characterization of two forms of cytochrome b5 from an arachidonic acid-producing fungus, Mortierella hygrophila.

    PubMed

    Kouzaki, N; Kawashima, H; Chung, M C; Shimizu, S

    1995-06-01

    Two forms of cytochrome b5 have been purified from the microsomes of an arachidonic acid-producing fungus, Mortierella hygrophila IFO 5941, after detergent solubilization. They have monomeric molecular masses of about 16 kDa and 19 kDa. Their absorption spectra are similar to those of mammalian cytochrome b5s. Their amino acid compositions show some similarity to those of mammalian cytochrome b5s, but the contents of some amino acids (glycine, alanine, aspartic acid + asparagine, glutamic acid + glutamine, arginine, proline, histidine, leucine and lysine) are unique to the cytochrome b5s of M. hygrophila. Some of their internal peptide sequences also show close homology with those of some mammals (approx. 65 to 67%), while some others show no or little homology. The addition of various acyl-CoAs to NADH-reduced microsomes caused an abrupt shiftdown of the steady state reduction level of cytochrome b5. This indicates the increased utilization of electrons for the desaturation process and may suggest that the cytochrome b5s of this fungus actually take part in its microsomal desaturation system for polyunsaturated fatty acid biosynthesis as electron carriers. PMID:7786894

  3. Involvement of the arachidonic acid cytochrome P450 epoxygenase pathway in the proliferation and invasion of human multiple myeloma cells

    PubMed Central

    Shao, Jing; Wang, Hongxiang; Yuan, Guolin; Chen, Zhichao

    2016-01-01

    Cytochrome P450 (CYP) epoxygenases and the metabolites epoxyeicosatrienoic acids (EETs) exert multiple biological effects in various malignancies. We have previously found EETs to be secreted by multiple myeloma (MM) cells and to be involved in MM angiogenesis, but the role of the arachidonic acid cytochrome P450 epoxygenase pathway in the proliferation and mobility of MM cells remains unknown. In the present study, we found that MM cell lines generated detectable levels of 11,12-EET/14,15-EET and that increased levels of EETs were found in the serum of MM patients compared to healthy donors. The addition of exogenous EETs induced significantly enhanced proliferation of MM cells, whereas 17-octadecynoic acid (17-ODYA), an inhibitor of the CYP epoxygenase pathway, inhibited the viability and proliferation of MM cells. Moreover, this inhibitory effect could be successfully reversed by exogenous EETs. 17-ODYA also inhibited the motility of MM cells in a time-dependent manner, with a reduction of the gelatinolytic activity and protein expression of the matrix metalloproteinases (MMP)-2 and MMP-9. These results suggest the CYP epoxygenase pathway to be involved in the proliferation and invasion of MM cells, for which 17-ODYA could be a promising therapeutic drug. PMID:27077015

  4. Exogenous arachidonic acid mediates permeability of human brain microvessel endothelial cells through prostaglandin E2 activation of EP3 and EP4 receptors.

    PubMed

    Dalvi, Siddhartha; Nguyen, Hieu H; On, Ngoc; Mitchell, Ryan W; Aukema, Harold M; Miller, Donald W; Hatch, Grant M

    2015-12-01

    The blood-brain barrier, formed by microvessel endothelial cells, is the restrictive barrier between the brain parenchyma and the circulating blood. Arachidonic acid (ARA; 5,8,11,14-cis-eicosatetraenoic acid) is a conditionally essential polyunsaturated fatty acid [20:4(n-6)] and is a major constituent of brain lipids. The current study examined the transport processes for ARA in confluent monolayers of human brain microvascular endothelial cells (HBMEC). Addition of radioactive ARA to the apical compartment of HBMEC cultured on Transwell(®) inserts resulted in rapid incorporation of radioactivity into the basolateral medium. Knock down of fatty acid transport proteins did not alter ARA passage into the basolateral medium as a result of the rapid generation of prostaglandin E2 (PGE2 ), an eicosanoid known to facilitate opening of the blood-brain barrier. Permeability following ARA or PGE2 exposure was confirmed by an increased movement of fluorescein-labeled dextran from apical to basolateral medium. ARA-mediated permeability was attenuated by specific cyclooxygenase-2 inhibitors. EP3 and EP4 receptor antagonists attenuated the ARA-mediated permeability of HBMEC. The results indicate that ARA increases permeability of HBMEC monolayers likely via increased production of PGE2 which acts upon EP3 and EP4 receptors to mediate permeability. These observations may explain the rapid influx of ARA into the brain previously observed upon plasma infusion with ARA. The blood-brain barrier, formed by microvessel endothelial cells, is a restrictive barrier between the brain parenchyma and the circulating blood. Radiolabeled arachidonic acid (ARA) movement across, and monolayer permeability in the presence of ARA, was examined in confluent monolayers of primary human brain microvessel endothelial cells (HBMECs) cultured on Transwell(®) plates. Incubation of HBMECs with ARA resulted in a rapid increase in HBMEC monolayer permeability. The mechanism was mediated, in part

  5. Arachidonic acid and prostaglandin E2 influence human osteoblast (MG63) response to titanium surface roughness.

    PubMed

    Dean, David D; Campbell, Casey M; Gruwell, Scott F; Tindall, John W M; Chuang, Hui-Hsiu; Zhong, Weinan; Schmitz, John P; Sylvia, Victor L

    2008-01-01

    Prior studies have shown that implant surface roughness affects osteoblast proliferation, differentiation, matrix synthesis, and local factor production. Further, cell response is modulated by systemic factors, such as 1,25(OH)2D3 and estrogen as well as mechanical forces. Based on the fact that peri-implant bone healing occurs in a site containing elevated amounts of prostaglandin E2 (PGE2), the hypothesis of the current study is that PGE2 and arachidonic acid (AA), the substrate used by cyclooxygenase to form PGE2, influence osteoblast response to implant surface roughness. To test this hypothesis, 4 different types of commercially pure titanium (cpTi) disks with surfaces of varying roughness (smooth Ti, R(a) 0.30 microm; smooth and acid etched Ti [SAE Ti], R(a) 0.40 microm; rough Ti, R(a) 4.3 microm; rough and acid etched Ti [RAE Ti], R(a) 4.15 (microm) were prepared. MG63 osteoblasts were seeded onto the surfaces, cultured to confluence, and then treated for the last 24 hours of culture with AA (0, 0.1, 1, and 10 nM), PGE2 (0, 1, 10, 25, and 100 nM), or the general cyclooxygenase inhibitor indomethacin (0 or 100 nM). At harvest, the effect of treatment on cell proliferation was assessed by measuring cell number and [3H]-thymidine incorporation, and the effect on cell differentiation was determined by measuring alkaline phosphatase (ALP) specific activity. The effect of AA and PGE2 on cell number was somewhat variable but showed a general decrease on plastic and smooth surfaces and an increase on rough surfaces. In contrast, [3H]-thymidine incorporation was uniformly decreased with treatment on all surfaces. ALP demonstrated the most prominent effect of treatment. On smooth surfaces, AA and PGE2 dose-dependently increased ALP, while on rough surfaces, treatment dose-dependently decreased enzyme specific activity. Indomethacin treatment had either no effect or a slightly inhibitory effect on [3H]-thymidine incorporation on all surfaces. In contrast, indomethacin

  6. Diverse ways of perturbing the human arachidonic acid metabolic network to control inflammation.

    PubMed

    Meng, Hu; Liu, Ying; Lai, Luhua

    2015-08-18

    Inflammation and other common disorders including diabetes, cardiovascular disease, and cancer are often the result of several molecular abnormalities and are not likely to be resolved by a traditional single-target drug discovery approach. Though inflammation is a normal bodily reaction, uncontrolled and misdirected inflammation can cause inflammatory diseases such as rheumatoid arthritis and asthma. Nonsteroidal anti-inflammatory drugs including aspirin, ibuprofen, naproxen, or celecoxib are commonly used to relieve aches and pains, but often these drugs have undesirable and sometimes even fatal side effects. To facilitate safer and more effective anti-inflammatory drug discovery, a balanced treatment strategy should be developed at the biological network level. In this Account, we focus on our recent progress in modeling the inflammation-related arachidonic acid (AA) metabolic network and subsequent multiple drug design. We first constructed a mathematical model of inflammation based on experimental data and then applied the model to simulate the effects of commonly used anti-inflammatory drugs. Our results indicated that the model correctly reproduced the established bleeding and cardiovascular side effects. Multitarget optimal intervention (MTOI), a Monte Carlo simulated annealing based computational scheme, was then developed to identify key targets and optimal solutions for controlling inflammation. A number of optimal multitarget strategies were discovered that were both effective and safe and had minimal associated side effects. Experimental studies were performed to evaluate these multitarget control solutions further using different combinations of inhibitors to perturb the network. Consequently, simultaneous control of cyclooxygenase-1 and -2 and leukotriene A4 hydrolase, as well as 5-lipoxygenase and prostaglandin E2 synthase were found to be among the best solutions. A single compound that can bind multiple targets presents advantages including low

  7. Diverse ways of perturbing the human arachidonic acid metabolic network to control inflammation.

    PubMed

    Meng, Hu; Liu, Ying; Lai, Luhua

    2015-08-18

    Inflammation and other common disorders including diabetes, cardiovascular disease, and cancer are often the result of several molecular abnormalities and are not likely to be resolved by a traditional single-target drug discovery approach. Though inflammation is a normal bodily reaction, uncontrolled and misdirected inflammation can cause inflammatory diseases such as rheumatoid arthritis and asthma. Nonsteroidal anti-inflammatory drugs including aspirin, ibuprofen, naproxen, or celecoxib are commonly used to relieve aches and pains, but often these drugs have undesirable and sometimes even fatal side effects. To facilitate safer and more effective anti-inflammatory drug discovery, a balanced treatment strategy should be developed at the biological network level. In this Account, we focus on our recent progress in modeling the inflammation-related arachidonic acid (AA) metabolic network and subsequent multiple drug design. We first constructed a mathematical model of inflammation based on experimental data and then applied the model to simulate the effects of commonly used anti-inflammatory drugs. Our results indicated that the model correctly reproduced the established bleeding and cardiovascular side effects. Multitarget optimal intervention (MTOI), a Monte Carlo simulated annealing based computational scheme, was then developed to identify key targets and optimal solutions for controlling inflammation. A number of optimal multitarget strategies were discovered that were both effective and safe and had minimal associated side effects. Experimental studies were performed to evaluate these multitarget control solutions further using different combinations of inhibitors to perturb the network. Consequently, simultaneous control of cyclooxygenase-1 and -2 and leukotriene A4 hydrolase, as well as 5-lipoxygenase and prostaglandin E2 synthase were found to be among the best solutions. A single compound that can bind multiple targets presents advantages including low

  8. Evaluation of Bioequivalency and Toxicological Effects of Three Sources of Arachidonic Acid (ARA) in Domestic Piglets

    PubMed Central

    Tyburczy, Cynthia; Brenna, Margaret E.; DeMari, Joseph A.; Kothapalli, Kumar S. D.; Blank, Bryant S.; Valentine, Helen; McDonough, Sean P.; Banavara, Dattatreya; Diersen-Schade, Deborah A.; Brenna, J. Thomas

    2011-01-01

    Arachidonic acid (ARA) and docosahexaenoic acid (DHA) are routinely added to infant formula to support growth and development. We evaluated the bioequivalence and safety of three ARA-rich oils for potential use in infant formula using the neonatal pig model. The primary outcome for bioequivalence was brain accretion of ARA and DHA. Days 3 to 22 of age, domestic pigs fed one of three formulas, each containing ARA at ~0.64% and DHA at ~0.34% total fatty acids (FA). Control diet ARA was provided by ARASCO® and all diets had DHA from DHASCO® (Martek Biosciences Corp., Columbia, MD). The experimental diets a1 and a2 provided ARA from Refined Arachidonic acid-rich Oil (RAO; Cargill, Inc., Wuhan, China) and SUNTGA40S (Nissui, Nippon Suisan Kaisha, Ltd., Tokyo, Japan), respectively. Formula intake and growth were similar across all diets, and ARA was bioequivalent across treatments in the brain, retina, heart, liver and day 21 RBC. DHA levels in the brain, retina and heart were unaffected by diet. Liver sections, clinical chemistry, and hematological parameters were normal. We conclude that RAO and SUNTGA40S, when added to formula to supply ~0.64% ARA are safe and nutritionally bioequivalent to ARASCO in domestic piglets. PMID:21722692

  9. The role of iron in prostaglandin synthesis: ferrous iron mediated oxidation of arachidonic acid.

    PubMed

    Rao, G H; Gerrard, J M; Eaton, J W; White, J G

    1978-07-01

    Arachidonic acid (AA) is the essential substrate for production of platelet endoperoxides and thromboxanes. Iron or heme is an essential cofactor for the peroxidase, lipoxygenase and cyclo-oxygenase enzymes involved in formation of these products. The present study has examined the direct interactions between iron and arachidonic acid. Iron caused the oxidation of AA into more polar products which could be detected by UV absorbtion at 232 nM or the thiobarbituric acid (TBA) reaction. High pressure liquid chromatography, chem-ionization and electron-impact mass spectrometry and nuclear magnetic resonance spectroscopy suggest that the major product was a hydroperoxide of AA. Ferrous iron (Fe++) and oxygen were absolute requirements. Fe++ was converted to the ferric iron (Fe+++) state during oxidation of AA, but Fe+++ could not substitute for Fe++. No other enzymes, cofactors or ions were involved. Conversion of AA to a hydroperoxide by Fe++ was inhibited by the antioxidant, 2, (3)-Tert-butyl-4-hydroxyanisole, the radical scavenger, nitroblue tetrazolium, and iron chelating agents, including EDTA, imidazole and dihydroxybenzoic acid. The reaction was not affected by superoxide dismutase, catalase or aspirin. These findings and preliminary studies of the Fe++ induced oxidation product of AA as a substrate for prostaglandin synthesis and inhibitor of prostacyclin production indicate the critical role of Fe++ in AA activation.

  10. Omega-3 PUFAs Lower the Propensity for Arachidonic Acid Cascade Overreactions.

    PubMed

    Lands, Bill

    2015-01-01

    A productive view of the benefits from omega-3 (n-3) nutrients is that the dietary essential omega-6 (n-6) linoleic acid has a very narrow therapeutic window which is widened by n-3 nutrients. The benefit from moderate physiological actions of the arachidonic acid cascade can easily shift to harm from excessive pathophysiological actions. Recognizing the factors that predispose the cascade to an unwanted overactivity gives a rational approach for arranging beneficial interactions between the n-3 and n-6 essential nutrients that are initial components of the cascade. Much detailed evidence for harmful cascade actions was collected by pharmaceutical companies as they developed drugs to decrease those actions. A remaining challenge is to understand the factors that predispose the cascade toward unwanted outcomes and create the need for therapeutic interventions. Such understanding involves recognizing the similar dynamics for dietary n-3 and n-6 nutrients in forming the immediate precursors of the cascade plus the more vigorous actions of the n-6 precursor, arachidonic acid, in forming potent mediators that amplify unwanted cascade outcomes. Tools have been developed to aid deliberate day-to-day quantitative management of the propensity for cascade overactivity in ways that can decrease the need for drug treatments.

  11. Arachidonic and eicosapentaenoic acid metabolism in bovine neutrophils and platelets: effect of calcium ionophore

    SciTech Connect

    Taylor, S.M.; Laegreid, W.W.; Heidel, J.R.; Straub, K.M.; Liggitt, H.D.; Silflow, R.M.; Breeze, R.G.; Leid, R.W.

    1987-09-01

    Substitution of dietary fatty acids has potential for altering the inflammatory response. The purpose of the present study was to define the metabolites of arachidonic acid (AA) and eicosapentaenoic acid (EPA) secreted by bovine peripheral blood neutrophils and platelets. High performance liquid chromatography was used to characterize cyclooxygenase and lipoxygenase metabolites secreted in response to the calcium ionophore A23187. Cells were prelabelled with /sup 3/H-AA or /sup 3/H-EPA prior to challenge with the calcium ionophore. Bovine neutrophils secreted leukotriene B4 (LTB4) and 5-hydroxyeicosatetraenoic acid (5-HETE) as the major metabolites of AA, as well as the corresponding leukotriene B5 (LTB5) and 5-hydroxyeicosapentaenoic acid (5-HEPE) metabolites of EPA. Peptidoleukotrienes derived from /sup 3/H-AA or /sup 3/H-EPA were not detected under these conditions. The major tritiated metabolites secreted from bovine platelets were: thromboxane A2, measured as the stable metabolite thromboxane B2 (TXB2); hydroxyheptadecatrienoic acid (HHT) and 12-HETE derived from /sup 3/H-AA; and the omega-3 analogs TXB3 and 12-HEPE, derived from /sup 3/H-EPA. Preferred substrate specificities existed amongst the AA- and EPA-derived metabolites for the intermediary enzymes involved in the arachidonic acid cascade. These findings support the hypothesis that substitution of membrane-bound AA by EPA has potential for modulation of the host inflammatory response following cellular phospholipid mobilization.

  12. Equine tracheal epithelial membrane strips - An alternate method for examining epithelial cell arachidonic acid metabolism

    SciTech Connect

    Gray, P.R.; Derksen, F.J.; Robinson, N.E.; Peter-Golden, M.L. Univ. of Michigan, Ann Arbor )

    1990-02-26

    Arachidonic acid metabolism by tracheal epithelium can be studied using enzymatically dispersed cell suspensions or cell cultures. Both techniques require considerable tissue disruption and manipulation and may not accurately represent in vivo activity. The authors have developed an alternate method for obtaining strips of equine tracheal epithelium without enzymatic digestion. In the horse, a prominent elastic lamina supports the tracheal epithelium. By physical splitting this lamina, they obtained strips ({le}12 x 1.5 cm) of pseudostratified columnar epithelium attached to a layer of elastic tissue 30-100 {mu}m thick. Epithelial strips (1.2 x 0.5 cm) were attached to plexiglass rods and incubated with ({sup 3}H)arachidonic acid in M199 medium (0.5 {mu}Ci/ml) for 24 hours at 37C. The strips incorporated 36{+-}4% (mean {+-} SEM) of the total radioactivity and released 8.0{+-}1.2% of incorporated radioactivity when stimulated by 5.0 {mu}M calcium ionophore A23187. The extracted supernatant was processed using HPLC, resulting in peaks of radioactivity that co-eluted with authentic PGE{sub 2}, PGF{sub 2}{alpha}, and 12-HETE standards. The greatest activity corresponded to the PGE{sub 2} and PGF{sub 2}{alpha} standards, which is a similar pattern to that reported for cultured human tracheal epithelium.

  13. Effect of ethanol amine plasmalogens on Fe-induced peroxidation of arachidonic acid in dipalmitoylphosphatidylcholine vesicles.

    PubMed

    Omodeo Salè, M F; Rizzo, A M; Masserini, M

    2000-12-01

    We have investigated the influence of ethanolamine plasmalogens on iron-induced oxidation of arachidonic acid in dipalmitoylphosphatidylcholine (DPPC) vesicles. Lipoperoxidation was induced by the addition of 50 microM FeSO4 and studied above (50 degrees C) and below (15 degrees C) the gel-to liquid transition temperature of the vesicles, at two different pH values (7.4 or 6.4). The extent of peroxidation was measured as thiobarbituric reactive product formed and the influence exerted by ethanolamine plasmalogens (PEPL) in this process was compared to that of dipalmitoylphosphatidylethanolamine (DPPE) and diacylphosphatidylethanolamines (DAPE). The extent of peroxidation of arachidonic acid embedded in DPPC vesicles was similar at the two temperatures and greater at 50 degrees C under acidic conditions. However, the peroxidative process was significantly decreased at 50 degrees C in the presence of PEPL, but not of DPPE or DAPE and the inhibitory effect was enhanced at pH 6.4. The possibility that a different phase distribution of the phospholipids, namely a transition from a lamellar to a hexagonal phase, may play a role in the scavenger effect of ethanolamine plasmalogens is discussed. PMID:11145167

  14. Plasma phospholipid arachidonic acid and lignoceric acid are associated with the risk of cardioembolic stroke.

    PubMed

    Chung, Hye-Kyung; Cho, Yoonsu; Do, Hyun Ju; Oh, Kyungmi; Seo, Woo-Keun; Shin, Min-Jeong

    2015-11-01

    Cardioembolic (CE) stroke is the most severe subtype of ischemic stroke with high recurrence and mortality. However, there is still little information on the association of plasma fatty acid (FA) with CE stroke. The objective of this study was to test the hypothesis whether the composition of plasma phospholipid FA is associated with the risk of CE stroke. The study subjects were collected from the Korea University Stroke Registry. Twenty-one subjects were selected as CE stroke group, and 39 age- and sex-matched subjects with non-CE stroke were selected as controls. Sociodemographic factors, clinical measurements, and plasma phospholipid FA compositions were compared between the groups. Logistic regression was used to obtain estimates of the associations between the relevant FAs and CE stroke. The result showed that the CE stroke group had higher levels of free FA and lower levels of triglycerides before and after adjustment (all P < .05). In the regression analysis, elaidic acid (18:1Tn9) and arachidonic acid (20:4n6) were positively related, but lignoceric acid (24:0) was negatively related to CE stroke in all constructed models (all P < .05). In conclusion, plasma phospholipid FA composition was associated with CE stroke risk in Korean population, with higher proportions of elaidic acid and arachidonic acid and lower proportion of lignoceric acid in CE stroke. PMID:26452419

  15. Omega-3 PUFAs Lower the Propensity for Arachidonic Acid Cascade Overreactions

    PubMed Central

    Lands, Bill

    2015-01-01

    A productive view of the benefits from omega-3 (n-3) nutrients is that the dietary essential omega-6 (n-6) linoleic acid has a very narrow therapeutic window which is widened by n-3 nutrients. The benefit from moderate physiological actions of the arachidonic acid cascade can easily shift to harm from excessive pathophysiological actions. Recognizing the factors that predispose the cascade to an unwanted overactivity gives a rational approach for arranging beneficial interactions between the n-3 and n-6 essential nutrients that are initial components of the cascade. Much detailed evidence for harmful cascade actions was collected by pharmaceutical companies as they developed drugs to decrease those actions. A remaining challenge is to understand the factors that predispose the cascade toward unwanted outcomes and create the need for therapeutic interventions. Such understanding involves recognizing the similar dynamics for dietary n-3 and n-6 nutrients in forming the immediate precursors of the cascade plus the more vigorous actions of the n-6 precursor, arachidonic acid, in forming potent mediators that amplify unwanted cascade outcomes. Tools have been developed to aid deliberate day-to-day quantitative management of the propensity for cascade overactivity in ways that can decrease the need for drug treatments. PMID:26301244

  16. Influence of phenolic constituents from Yucca schidigera bark on arachidonate metabolism in vitro.

    PubMed

    Wenzig, Eva M; Oleszek, Wieslaw; Stochmal, Anna; Kunert, Olaf; Bauer, Rudolf

    2008-10-01

    Yucca schidigera Roezl. (Agavaceae) has been traditionally used to treat a variety of diseases including arthritis and rheumatism. Phenolic constituents isolated from yucca bark, such as resveratrol, trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene, and the yuccaols, have been shown to possess various activities in vitro, such as antioxidant, radical scavenging, iNOS expression inhibitory, and platelet aggregation inhibitory effects. In the present study, the influence of a phenolic-rich fraction from yucca bark and of its main phenolic constituents on key enzymes of arachidonate metabolism was investigated. The fraction and the pure phenolics were shown to inhibit COX-1, COX-2, and LTB 4 formation by 5-LOX in vitro to different extents. The degree of COX-1 inhibition was found to be strongly dependent on the substitution pattern of ring B of the stilbenic moiety. The same trend was observed for the COX-2 inhibitory potential, which was, however, in general much lower for the yuccaols as compared with resveratrol. Resveratrol was also the only compound possessing an LTB 4 formation inhibitory activity. The inhibitory activity on key enzymes of arachidonate metabolism observed in this study might contribute to the explanation of the anti-inflammatory and antiplatelet effects observed for Y. schidigera and its phenolic constituents.

  17. Arachidonic acid-induced mobilization of calcium in human neutrophils: evidence for a multicomponent mechanism of action.

    PubMed Central

    Naccache, P. H.; McColl, S. R.; Caon, A. C.; Borgeat, P.

    1989-01-01

    1. The mechanism(s) involved in the mobilization of calcium induced by arachidonic acid in human neutrophils was investigated. 2. The addition of arachidonic acid to a suspension of human neutrophils led to a time- and concentration-dependent mobilization of calcium which was the result of two separate and experimentally differentiable processes. The latter consisted of a rapid and transient phase followed by a slower and more sustained response. 3. The initial phase of calcium mobilization elicited by arachidonic acid was decreased in the presence of EGTA, inhibited by pertussis toxin as well as by nordihydroguaiaretic acid (NDGA), and diminished following a pre-incubation with leukotriene B4, but not platelet-activating factor. 4. The characteristics of the first phase of the mobilization of calcium were consistent with an interaction of the fatty acid with the leukotriene B4 receptors, either directly or indirectly following the synthesis of leukotriene B4, as well as with a release of internal calcium. 5. The second, slower and more sustained phase of calcium mobilization was more apparent at high concentrations (greater than or equal to 8-16 microM) of arachidonic acid, and was relatively insensitive to pertussis toxin, EGTA or NDGA. 6. The characteristics of the 'slow' phase of calcium mobilization by arachidonic acid are consistent with its being associated primarily with a release of calcium from internal storage pools. 7. The data presented indicate that the mechanism of mobilization of calcium by arachidonic acid in human neutrophils is complex and involves specific activation pathways employed, in part at least, by other neutrophil agonists.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2547474

  18. Anger induced by interferon-alpha is moderated by ratio of arachidonic acid to omega-3 fatty acids

    PubMed Central

    Lotrich, Francis E.; Sears, Barry; McNamara, Robert K.

    2013-01-01

    Objective Anger worsens in some patients during interferon-alpha (IFN-α) therapy. Elevated anger has also been associated with lower long-chain omega-3 (LCn-3) fatty acid levels. We examined whether fatty acids could influence vulnerability to anger during IFN-α exposure. Methods Plasma arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) levels were determined prior to IFN-α therapy by mass spectroscopy. Repeated-measure analyses examined the relationship between AA/EPA+DHA and the subsequent development of labile anger and irritability in 82 subjects who prospectively completed the Anger, Irritability, and Assault Questionnaire (AIAQ) during the first eight weeks of IFN-α therapy. Results Prior to IFN-α therapy, AA/EPA+DHA did not correlate with either labile anger or irritability. Pre-treatment AA/EPA+DHA did correlate with the subsequent maximal increase in labile anger during IFN-α therapy (r=0.33; p=0.005). Over time, labile anger increased more in subjects with above median AA/EPA+DHA ratios (p<0.05). Of the 17 subjects ultimately requiring psychiatric intervention for anger, 14/17 had above-median AA/EPA+DHA ratios (p=0.009). There was also an interaction with the tumor necrosis factor-alpha (TNF-α) promoter polymorphism (A-308G), such that only those with both elevated AA/EPA+DHA and the A allele had increased labile anger (p=0.001). In an additional 18 subjects, we conversely observed that selective serotonin reuptake inhibitor treatment was associated with increased irritability during IFN-α therapy. Conclusion LCn-3 fatty acid status may influence anger development during exposure to elevated inflammatory cytokines, and may interact with genetic risk for increased brain TNF-α. LCn-3 supplements may be one strategy for minimizing this adverse side effect of IFN-α. PMID:24182638

  19. Protein tyrosine phosphatases regulate arachidonic acid release, StAR induction and steroidogenesis acting on a hormone-dependent arachidonic acid-preferring acyl-CoA synthetase.

    PubMed

    Cano, Florencia; Poderoso, Cecilia; Cornejo Maciel, Fabiana; Castilla, Rocío; Maloberti, Paula; Castillo, Fernanda; Neuman, Isabel; Paz, Cristina; Podestá, Ernesto J

    2006-06-01

    The activation of the rate-limiting step in steroid biosynthesis, that is the transport of cholesterol into the mitochondria, is dependent on PKA-mediated events triggered by hormones like ACTH and LH. Two of such events are the protein tyrosine dephosphorylation mediated by protein tyrosine phosphatases (PTPs) and the release of arachidonic acid (AA) mediated by two enzymes, ACS4 (acyl-CoA synthetase 4) and Acot2 (mitochondrial thioesterase). ACTH and LH regulate the activity of PTPs and Acot2 and promote the induction of ACS4. Here we analyzed the involvement of PTPs on the expression of ACS4. We found that two PTP inhibitors, acting through different mechanisms, are both able to abrogate the hormonal effect on ACS4 induction. PTP inhibitors also reduce the effect of cAMP on steroidogenesis and on the level of StAR protein, which facilitates the access of cholesterol into the mitochondria. Moreover, our results indicate that exogenous AA is able to overcome the inhibition produced by PTP inhibitors on StAR protein level and steroidogenesis. Then, here we describe a link between PTP activity and AA release, since ACS4 induction is under the control of PTP activity, being a key event for AA release, StAR induction and steroidogenesis.

  20. Oleanolic Acid Prevents Increase in Blood Pressure and Nephrotoxicity in Nitric Oxide Dependent Type of Hypertension in Rats

    PubMed Central

    Bachhav, Sagar S.; Bhutada, Mukesh S.; Patil, Sachin P.; Sharma, Kinjal S.; Patil, Savita D.

    2015-01-01

    Background: Recently, we have reported antihypertensive activity of oleanolic acid (OA) in glucocorticoid-induced hypertension with restoration of nitric oxide (NO) level. However, the involvement of NO-releasing action of OA was unclear. Objective: To explore antihypertensive activity of OA in Nω-nitro-L-arginine methyl ester (L-NAME) hypertensive rats wherein NO is completely blocked, which would allow exploring the possibility of involvement of NO-releasing action of OA. Materials and Methods: Five groups of rats were investigated as normal control, L-NAME (40 mg/kg/day), L-NAME + enalapril (15 mg/kg/day), L-NAME + l-arginine (100 mg/kg/day), and L-NAME + OA (60 mg/kg/day) for 4 weeks. The systolic blood pressure, body weight, and heart rate were measured weekly for 4 weeks. Serum nitrate/nitrite (NOx) level, urine electrolytes concentration, cardiac mass index, and serum creatinine level were determined followed by organ histopathology. Results: OA and enalapril delayed the rise in blood pleasure following L-NAME administration. Decreased serum NOx level was not significantly increased with any of the treatment. OA produced a small, though nonsignificant, increase in the NOx level. L-NAME administration did not affect cardiac mass index. There was an increase in serum creatinine upon L-NAME administration which was prevented by OA. Decreased urine volume, urine sodium and potassium were reversed by OA. Conclusion: These results suggest that the antihypertensive effect of OA in L-NAME hypertension is due to diuresis and nephroprotection. However, OA has nonsignificantly affected the NO levels. PMID:26692754

  1. Adenoviral expression of 15-lipoxygenase-1 in rabbit aortic endothelium: role in arachidonic acid-induced relaxation.

    PubMed

    Aggarwal, Nitin T; Holmes, Blythe B; Cui, Lijie; Viita, Helena; Yla-Herttuala, Seppo; Campbell, William B

    2007-02-01

    Endothelium-dependent vasorelaxation of the rabbit aorta is mediated by either nitric oxide (NO) or arachidonic acid (AA) metabolites from cyclooxygenase (COX) and 15-lipoxygenase (15-LO) pathways. 15-LO-1 metabolites of AA, 11,12,15-trihydroxyeicosatrienoic acid (THETA), and 15-hydroxy-11,12-epoxyeicosatrienoic acid (HEETA) cause concentration-dependent relaxation. We tested the hypothesis that in the 15-LO pathway of AA metabolism, 15-LO-1 is sufficient and is the rate-limiting step in inducing relaxations in rabbit aorta. Aorta and rabbit aortic endothelial cells were treated with adenoviruses containing human 15-LO-1 cDNA (Ad-15-LO-1) or beta-galactosidase (Ad-beta-Gal). Ad-15-LO-1-transduction increased the expression of a 75-kDa protein corresponding to 15-LO-1, detected by immunoblotting with an anti-human15-LO-1 antibody, and increased the production of HEETA and THETA from [(14)C]AA. Immunohistochemical studies on Ad-15-LO-1-transduced rabbit aorta showed the presence of 15-LO-1 in endothelial cells. Ad-15-LO-1-treated aortic rings showed enhanced relaxation to AA (max 31.7 +/- 3.2%) compared with Ad-beta-Gal-treated (max 12.7 +/- 3.2%) or control nontreated rings (max 13.1 +/- 1.6%) (P < 0.01). The relaxations in Ad-15-LO-1-treated aorta were blocked by the 15-LO inhibitor cinnamyl-3,4-dihydroxy-a-cyanocinnamate. Overexpression of 15-LO-1 in the rabbit aortic endothelium is sufficient to increase the production of the vasodilatory HEETA and THETA and enhance the relaxations to AA. This confirms the role of HEETA and THETA as endothelium-derived relaxing factors.

  2. IMAGING SIGNAL TRANSDUCTION VIA ARACHIDONIC ACID IN THE HUMAN BRAIN DURING VISUAL STIMULATION, BY MEANS OF POSITRON EMISSION TOMOGRAPHY

    PubMed Central

    Esposito, Giuseppe; Giovacchini, Giampiero; Der, Margaret; Liow, Jeih-San; Bhattacharjee, Abesh K.; Ma, Kaizong; Herscovitch, Peter; Channing, Michael; Eckelman, William C.; Hallett, Mark; Carson, Richard E.; Rapoport, Stanley I.

    2007-01-01

    Background Arachidonic acid (AA, 20:4n-6), an important second messenger, is released from membrane phospholipid following receptor mediated activation of phospholipase A2 (PLA2). This signaling process can be imaged in brain as a regional brain AA incorporation coefficient K*. Hypothesis K* will be increased in brain visual areas of subjects submitted to visual stimulation. Subjects and methods Regional values of K* were measured with positron emission tomography (PET), following the intravenous injection of [1-11C]AA, in 16 healthy volunteers subjected to visual stimulation at flash frequencies 2.9 Hz (8 subjects) or 7.8 Hz (8 subjects), compared with the dark (0 Hz) condition. Regional cerebral blood flow (rCBF) was measured with intravenous [15O]water under comparable conditions. Results During flash stimulation at 2.9 Hz or 7.8 Hz vs. 0 Hz, K* was increased significantly by 2.3–8.9% in Brodmann areas 17, 18 and 19, and in additional frontal, parietal and temporal cortical regions. rCBF was increased significantly by 3.1% – 22%, often in comparable regions. Increments at 7.8 Hz often exceeded those at 2.9 Hz for both K* and rCBF. Decrements in both parameters also were produced, particularly in frontal brain regions. Conclusions AA plays a role in signaling processes provoked by visual stimulation, since visual stimulation at flash frequencies of 2.9 and 7.8 Hz compared to 0 Hz modifies both K* for AA and rCBF in visual and related areas of the human brain. The two-stimulus condition paradigm of this study might be used with PET to image effects of other functional activations and of drugs on brain signaling via AA. PMID:17196833

  3. Phenylethanoids in the herb of Plantago lanceolata and inhibitory effect on arachidonic acid-induced mouse ear edema.

    PubMed

    Murai, M; Tamayama, Y; Nishibe, S

    1995-10-01

    The five phenylethanoids, acteoside (1), cistanoside F (2), lavandulifolioside (3), plantamajoside (4) and isoacteoside (5) were isolated from the herb of Plantago lanceolata L. (Plantaginaceae). Compounds 1, the major phenylethanoid in the herb of P. lanceolata L., and 4, the major phenylethanoid in the herb of P. asiatica L., showed inhibitory effects on arachidonic acid-induced mouse ear edema. PMID:7480214

  4. Phenylethanoids in the herb of Plantago lanceolata and inhibitory effect on arachidonic acid-induced mouse ear edema.

    PubMed

    Murai, M; Tamayama, Y; Nishibe, S

    1995-10-01

    The five phenylethanoids, acteoside (1), cistanoside F (2), lavandulifolioside (3), plantamajoside (4) and isoacteoside (5) were isolated from the herb of Plantago lanceolata L. (Plantaginaceae). Compounds 1, the major phenylethanoid in the herb of P. lanceolata L., and 4, the major phenylethanoid in the herb of P. asiatica L., showed inhibitory effects on arachidonic acid-induced mouse ear edema.

  5. Retroconversion of docosapentaenoic acid (n-6): an alternative pathway for biosynthesis of arachidonic acid in Daphnia magna.

    PubMed

    Strandberg, Ursula; Taipale, Sami J; Kainz, Martin J; Brett, Michael T

    2014-06-01

    The aim of this study was to assess metabolic pathways for arachidonic acid (20:4n-6) biosynthesis in Daphnia magna. Neonates of D. magna were maintained on [(13)C] enriched Scenedesmus obliquus and supplemented with liposomes that contained separate treatments of unlabeled docosapentaenoic acid (22:5n-6), 20:4n-6, linoleic acid (18:2n-6) or oleic acid (18:1n-9). Daphnia in the control treatment, without any supplementary fatty acids (FA) containing only trace amounts of 20:4n-6 (~0.3% of all FA). As expected, the highest proportion of 20:4n-6 (~6.3%) was detected in Daphnia that received liposomes supplemented with this FA. Higher availability of 18:2n-6 in the diet increased the proportion of 18:2n-6 in Daphnia, but the proportion of 20:4n-6 was not affected. Daphnia supplemented with 22:5n-6 contained ~3.5% 20:4n-6 in the lipids and FA specific stable isotope analyses validated that the increase in the proportion of 20:4n-6 was due to retroconversion of unlabeled 22:5n-6. These results suggest that chain shortening of 22:5n-6 is a more efficient pathway to synthesize 20:4n-6 in D. magna than elongation and desaturation of 18:2n-6. These results may at least partially explain the discrepancies noticed between phytoplankton FA composition and the expected FA composition in freshwater cladocerans. Finally, retroconversion of dietary 22:5n-6 to 20:4n-6 indicates Daphnia efficiently retain long chain n-6 FA in lake food webs, which might be important for the nutritional ecology of fish.

  6. Ethanol Promotes Chemically Induced Oral Cancer in Mice through Activation of the 5-Lipoxygenase Pathway of Arachidonic Acid Metabolism

    PubMed Central

    Guo, Yizhu; Wang, Xin; Zhang, Xinyan; Sun, Zheng; Chen, Xiaoxin

    2011-01-01

    Alcohol drinking is a known risk factor for oral cancer in humans. However, previous animal studies on the promoting effect of ethanol on oral carcinogenesis were inconclusive. It is necessary to develop an animal model with which the molecular mechanism of ethanol-related oral carcinogenesis may be elucidated in order to develop effective prevention strategies. In this study, mice were first treated with 4-nitroquinoline-1-oxide (4NQO, 100μg/ml in drinking water) for 8 weeks, and then given water or ethanol (8%) as the sole drink for another 16 weeks. During the experiment, 8% ethanol was well tolerated by mice. The incidence of squamous cell carcinoma (SCC) increased from 20% (8/41) to 43% (17/40; p<0.05). Expression of 5-lipoxygenase (5-Lox) and cyclooxygenase 2 (Cox-2) was increased in dysplasia and SCC of 4NQO-treated tongues, and further enhanced by ethanol. Using this mouse model, we further demonstrated that fewer cancers were induced in Alox5−/− mice, as were cell proliferation, inflammation, and angiogenesis in the tongue, as compared with Alox5+/+ mice. Interestingly, Cox-2 expression was induced by ethanol in knockout mice, while 5-Lox and leukotriene A4 hydrolase (LTA4H) expression and leukotriene B4 (LTB4) biosynthesis were dramatically reduced. Moreover, ethanol enhanced expression and nuclear localization of 5-Lox and stimulated LTB4 biosynthesis in human tongue SCC cells (SCC-15 and SCC-4) in vitro. In conclusion, this study clearly demonstrated that ethanol promoted 4NQO-induced oral carcinogenesis, at least in part, through further activation of the 5-Lox pathway of arachidonic acid metabolism. PMID:21881027

  7. Rapid extraction of oxygenated metabolites of arachidonic acid from biological samples using octadecylsilyl silica.

    PubMed

    Powell, W S

    1980-11-01

    A rapid procedure for the efficient extraction of prostaglandins, thromboxanes and hydroxy fatty acids from urine, plasma and tissue homogenates has been developed. Fractions containing these substances are acidified and passed through a column of octadecylsilyl silica, which retains oxygenated metabolites of arachidonic acid. Phospholipids, proteins and very polar materials either are not retained or can be eluted with dilute aqueous ethanol. Nonpolar lipids and monohydroxy fatty acids are then eluted with petroleum ether or benzene. Subsequent elution of the column with methyl formate gives a fraction containing prostaglandins and thromboxanes which is much less contaminated with extraneous material than that obtained by conventional extraction of aqueous media with organic solvents. The methyl formate can be removed rapidly under a stream of nitrogen and the components of the sample purified directly by high pressure liquid chromatography (HPLC). An improved method for the purification of prostaglandins and TXB2 by HPLC on silica columns is reported.

  8. Neutrophil chemotaxis and arachidonic acid metabolism are not linked: evidence from metal ion probe studies

    SciTech Connect

    Turner, S.R.; Turner, R.A.; Smith, D.M.; Johnson, J.A.

    1986-03-05

    Heavy metal ions can inhibit arachidonic acid (AA) metabolism protect against ionophore cytotoxicity (ibid) and inhibit neutrophil chemotaxis. In this study they used Au/sup 3 +/, Zn/sup 2 +/, Cr/sup 3 +/, Mn/sup 2 +/ and Cu/sup 2 +/ as probes of the interrelationships among AA metabolism, ionophore-mediated cytotoxicity, and chemotaxis. Phospholipid deacylation was measured in ionophore-treated cells prelabeled with /sup 3/H-AA. Eicosanoid release from ionophore-treated cells was monitored by radioimmunoassay. Cytoprotection was quantitated as ability to exclude trypan blue. Chemotaxis toward f-met-leu-phe was measured by leading front analysis. The results imply that metal ions attenuate ionophore cytotoxicity by blocking phospholipid deacylation and eicosanoid release. In contrast to previous reports, no correlation between AA metabolism and chemotaxis was demonstrated, suggesting that these 2 processes are not linked.

  9. Eicosanoids Derived From Arachidonic Acid and Their Family Prostaglandins and Cyclooxygenase in Psychiatric Disorders

    PubMed Central

    Yui, Kunio; Imataka, George; Nakamura, Hiroyuki; Ohara, Naoki; Naito, Yukiko

    2015-01-01

    Arachidonic acid (AA)-derived lipid mediators are called eicosanoids. Eicosanoids have emerged as key regulators of a wide variety of physiological responses and pathological processes, and control important cellular processes. AA can be converted into biologically active compounds by metabolism by cyclooxygenases (COX). Beneficial effect of COX-2 inhibitor celecoxib add-on therapy has been reported in early stage of schizophrenia. Moreover, add-on treatment of celecoxib attenuated refractory depression and bipolar depression. Further, the COX/prostaglandin E pathway play an important role in synaptic plasticity and may be included in pathophysiology in autism spectrum disorders (ASD). In this regard, plasma transferrin, which is an iron mediator related to eicosanoid signaling, may be related to social impairment of ASD. COX-2 is typically induced by inflammatory stimuli in the majority of tissues, and the only isoform responsible for propagating the inflammatory response. Thus, COX-2 inhibitors considered as the best target for Alzheimer’s disease. PMID:26521945

  10. Arachidonic Acid Derivatives and Their Role in Peripheral Nerve Degeneration and Regeneration

    PubMed Central

    Camara-Lemarroy, Carlos Rodrigo; Gonzalez-Moreno, Emmanuel Irineo; Guzman-de la Garza, Francisco Javier; Fernandez-Garza, Nancy Esthela

    2012-01-01

    After peripheral nerve injury, a process of axonal degradation, debris clearance, and subsequent regeneration is initiated by complex local signaling, called Wallerian degeneration (WD). This process is in part mediated by neuroglia as well as infiltrating inflammatory cells and regulated by inflammatory mediators such as cytokines, chemokines, and the activation of transcription factors also related to the inflammatory response. Part of this neuroimmune signaling is mediated by the innate immune system, including arachidonic acid (AA) derivatives such as prostaglandins and leukotrienes. The enzymes responsible for their production, cyclooxygenases and lipooxygenases, also participate in nerve degeneration and regeneration. The interactions between signals for nerve regeneration and neuroinflammation go all the way down to the molecular level. In this paper, we discuss the role that AA derivatives might play during WD and nerve regeneration, and the therapeutic possibilities that arise. PMID:22997489

  11. Eicosapentaenoic and arachidonic acids purification from the red microalga Porphyridium cruentum.

    PubMed

    Guil-Guerrero, J L; Belarbi, E H; Rebolloso-Fuentes, M M

    2000-01-01

    The polyunsaturated fatty acids (PUFA) eicosapentaenoic and arachidonic acids (EPA and AA), which have several pharmaceutical properties, have been purified from the red microalga Porphyridium cruentum. The process consists of only four main steps: (i) simultaneous extraction and saponification of the microalgal biomass; (ii) urea inclusion method (iii) PUFA esterification (iv) argentated silica gel column chromatography of the urea concentrate. Total AA and EPA recoveries reached 39.5% and 50.8% respectively for a purity approximately 97% for both fatty acids. Therefore, recovery of highly pure PUFA could be improved in organisms that are rich in two or more fatty acids of interest. The results of several procedures for AA and EPA recovery from several authors by using this microalga were compared.

  12. Arachidonic acid diet attenuates brain Aβ deposition in Tg2576 mice.

    PubMed

    Hosono, Takashi; Nishitsuji, Kazuchika; Nakamura, Toshiyuki; Jung, Cha-Gyun; Kontani, Masanori; Tokuda, Hisanori; Kawashima, Hiroshi; Kiso, Yoshinobu; Suzuki, Toshiharu; Michikawa, Makoto

    2015-07-10

    The amyloid β-protein (Aβ) is believed to play a causative role in the development of Alzheimer's disease (AD). Because the amyloid precursor protein (APP), a substrate of Aβ, and β-secretase and γ-secretase complex proteins, which process APP to generate Aβ, are all membrane proteins, it is possible to assume that alterations in brain lipid metabolism modulate APP and/or Aβ metabolism. However, the role of polyunsaturated fatty acids in Aβ metabolism remains unknown. We report here that 9 months-treatment of Tg2576 mice with arachidonic acid (ARA)-containing (ARA+) diet prevented brain Aβ deposition in 17-month-old Tg2576 mice. APP processing to generate soluble APPα, CTF-β, and Aβ synthesis was attenuated in Tg2576 mice fed with the ARA+ diet. These findings suggest that ARA+ diet could prevent Aβ deposition through the alteration of APP processing in Tg2576 mice.

  13. The Synthesis and In Vivo Pharmacokinetics of Fluorinated Arachidonic Acid: Implications for Imaging Neuroinflammation

    PubMed Central

    Pichika, Rama; Taha, Ameer Y.; Gao, Fei; Kotta, Kishore; Cheon, Yewon; Chang, Lisa; Kiesewetter, Dale; Rapoport, Stanley I.; Eckelman, William C.

    2012-01-01

    Arachidonic acid (AA) is found in high concentrations in brain phospholipids and is released as a second messenger during neurotransmission and much more so during neuroinflammation and excitotoxicity. Upregulated brain AA metabolism associated with neuroinflammation has been imaged in rodents using [1-14C]AA and with PET in Alzheimer disease patients using [1-11C]AA. Radiotracer brain AA uptake is independent of cerebral blood flow, making it an ideal tracer despite altered brain functional activity. However, the 20.4-min radioactive half-life of 11C-AA and challenges of routinely synthesizing 11C fatty acids limit their translational utility as PET biomarkers. Methods As a first step to develop a clinically useful 18F-fluoroarachidonic acid (18F-FAA) with a long radioactive half-life of 109.8 min, we report here a high-yield stereoselective synthetic method of non-radioactive 20-19F-FAA. We tested its in vivo pharmacokinetics by infusing purified nonradioactive 19F-FAA intravenously for 5 min at 2 doses in unanesthetized mice and measured its plasma and brain distribution using gas chromatography–mass spectrometry. Results Incorporation coefficients of injected 19F-FAA into brain phospholipids (ratio of brain 19F-FAA concentration to plasma input function) were 3- to 29-fold higher for choline glycerophospholipid and phosphatidylinositol than for ethanolamine glycerophospholipid and phosphatidylserine at each of the 2 tested doses. The selectivities and values of incorporation coefficients were comparable to those reported after [1-14C]AA (the natural arachidonate) infusion in mice. Conclusion These results suggest that it would be worthwhile to translate our stereoselective synthetic method for 19F-FAA to synthesize positron-emitting 18F-FAA for human brain AA metabolism in neuroinflammatory disorders such as Alzheimer disease. PMID:22851635

  14. In Vitro and In Vivo Activities of Arachidonic Acid against Schistosoma mansoni and Schistosoma haematobium▿

    PubMed Central

    El Ridi, Rashika; Aboueldahab, Marwa; Tallima, Hatem; Salah, Mohamed; Mahana, Noha; Fawzi, Samia; Mohamed, Shadia H.; Fahmy, Omar M.

    2010-01-01

    The development of arachidonic acid (ARA) for treatment of schistosomiasis is an entirely novel approach based on a breakthrough discovery in schistosome biology revealing that activation of parasite tegument-bound neutral sphingomyelinase (nSMase) by unsaturated fatty acids, such as ARA, induces exposure of parasite surface membrane antigens to antibody binding and eventual attrition of developing schistosomula and adult worms. Here, we demonstrate that 5 mM ARA leads to irreversible killing of ex vivo 1-, 3-, 4-, 5-, and 6-week-old Schistosoma mansoni and 9-, 10-, and 12-week-old Schistosoma haematobium worms within 3 to 4 h, depending on the parasite age, even when the worms were maintained in up to 50% fetal calf serum. ARA-mediated worm attrition was prevented by nSMase inhibitors, such as CaCl2 and GW4869. Scanning and transmission electron microscopy revealed that ARA-mediated worm killing was associated with spine destruction, membrane blebbing, and disorganization of the apical membrane structure. ARA-mediated S. mansoni and S. haematobium worm attrition was reproduced in vivo in a series of 6 independent experiments using BALB/c or C57BL/6 mice, indicating that ARA in a pure form (Sigma) or included in infant formula (Nestle) consistently led to 40 to 80% decrease in the total worm burden. Arachidonic acid is already marketed for human use in the United States and Canada for proper development of newborns and muscle growth of athletes; thus, ARA has potential as a safe and cost-effective addition to antischistosomal therapy. PMID:20479203

  15. In vitro and in vivo activities of arachidonic acid against Schistosoma mansoni and Schistosoma haematobium.

    PubMed

    El Ridi, Rashika; Aboueldahab, Marwa; Tallima, Hatem; Salah, Mohamed; Mahana, Noha; Fawzi, Samia; Mohamed, Shadia H; Fahmy, Omar M

    2010-08-01

    The development of arachidonic acid (ARA) for treatment of schistosomiasis is an entirely novel approach based on a breakthrough discovery in schistosome biology revealing that activation of parasite tegument-bound neutral sphingomyelinase (nSMase) by unsaturated fatty acids, such as ARA, induces exposure of parasite surface membrane antigens to antibody binding and eventual attrition of developing schistosomula and adult worms. Here, we demonstrate that 5 mM ARA leads to irreversible killing of ex vivo 1-, 3-, 4-, 5-, and 6-week-old Schistosoma mansoni and 9-, 10-, and 12-week-old Schistosoma haematobium worms within 3 to 4 h, depending on the parasite age, even when the worms were maintained in up to 50% fetal calf serum. ARA-mediated worm attrition was prevented by nSMase inhibitors, such as CaCl(2) and GW4869. Scanning and transmission electron microscopy revealed that ARA-mediated worm killing was associated with spine destruction, membrane blebbing, and disorganization of the apical membrane structure. ARA-mediated S. mansoni and S. haematobium worm attrition was reproduced in vivo in a series of 6 independent experiments using BALB/c or C57BL/6 mice, indicating that ARA in a pure form (Sigma) or included in infant formula (Nestle) consistently led to 40 to 80% decrease in the total worm burden. Arachidonic acid is already marketed for human use in the United States and Canada for proper development of newborns and muscle growth of athletes; thus, ARA has potential as a safe and cost-effective addition to antischistosomal therapy. PMID:20479203

  16. Surfactant-induced alteration of arachidonic acid metabolism of mammalian cells in culture.

    PubMed

    De Leo, V A; Harber, L C; Kong, B M; De Salva, S J

    1987-04-01

    Primary irritancy in human and animal skin is characterized by an inflammatory reaction mediated, in part, by membrane-derived arachidonate metabolites. One of the mechanisms of this reaction was investigated in cultured mammalian cells using three surfactants: linear alkyl benzene sulfonate (LAS), alkyl ethoxylate sulfate (AEOS), and TWEEN 20. These compounds listed in order in vivo irritancy are LAS greater than AEOS greater than TWEEN 20. Each of these compounds was studied in C3H-10T1/2 cells and human keratinocytes which had been prelabeled with 3H-labeled arachidonic acid (AA). After labeling, media were removed, cells were washed, and fresh media with or without surfactant were added. Cells were then incubated for 2 hr, media were removed and centrifuged, and an aliquot was assayed by liquid scintillation for release of label. In C3H-10T1/2 cells LAS and AEOS in 5-50 microM concentration stimulated 2 to 10 times the release of [3H]AA as compared to controls. In contrast, concentrations of 50-100 microM of TWEEN were required to release [3H]AA. With keratinocytes the same rank order of surfactant concentrations necessary for release was obtained as found with C3H-10T1/2 cells. High-performance liquid chromatography of media extracts of both cell systems revealed surfactant stimulation of the production of cyclooxygenase AA metabolites. These results confirm the induction of release by primary irritants of fatty acid groups from membrane phospholipids. Subsequent metabolism of these fatty acid groups are an integral part of the primary irritant response. Data presented with three known irritants in this in vitro model show a direct correlation with in vivo studies.

  17. Products of ozonized arachidonic acid potentiate the formation of DNA single strand breaks in cultured human lung cells

    SciTech Connect

    Kozumbo, W.J.; Hanley, N.M.; Agarwal, S.

    1996-12-31

    In this study we examined the potential for environmental levels of ozone (O{sub 3}) to degrade arachidonic acid (AA), a polyunsaturated fatty acid abundantly present in the lung, into products that can produce DNA single strand breaks (ssb) in cultured human lung cells. Human lung fibroblasts were incubated with 60 {mu}M AA that had been previously exposed to an degraded by 0.4 ppm O{sub 3} (1 hr). Incubation of the cells with O{sub 3}-exposed AA (but not with vehicle alone) for 1 hr at 4{degrees}C and 37{degrees}C produced 555 and 245 rad-equivalents of DNA ssb, respectively, as determined by the DNA alkaline elution technique. These breaks were completely eliminated when the ozonized AA solution was incubated with catalase prior to cell treatment, indicating that H{sub 2}O{sub 2} was solely responsible for damaging DNA. Superoxide dismutase, bovine serum albumin, or heat-inactivated catalase showed little, if any, inhibitory activity. The H{sub 2}O{sub 2} content for only about 40% of the observed breaks. Potentiation of the H{sub 2}O{sub 2}-induced DNA ssb persisted after removal of the carbonyl substances by chromatographic procedures, suggesting that the non-carbonyl component of ozonized AA was the responsible component for inducing augmentation of the observed increases in DNA ssb. Ozonized AA also induced DNA ssb in cultures of the human bronchial epithelial cell line BEAS-2B. Again, these breaks were shown to exceed levels that could be attributed to the presence of H{sub 2}O{sub 2} alone. These results indicate that products of ozonized AA can interact to potentiate DNA ssb in human lung cells. 42 refs., 6 figs., 3 tabs.

  18. Lyso(bis)phosphatidic acid: a preferred donor of arachidonic acid for macrophage-synthesis of eicosanoids

    SciTech Connect

    Cochran, F.; Roddick, V.; Connor, J.; Waite, M.

    1986-05-01

    In order to dissect mechanisms of arachidonic acid (20:4) metabolism, two cell populations were investigated, resident (AM) and Bacillus Calmette-Guerin-activated (BCG-AM) rabbit alveolar macrophages. After purified AM were labeled overnight with (/sup 3/H)20:4, radioactivity was localized primarily within lyso(bis)phosphatidic acid (L(bis)PA) (13.1%), phosphatidylethanolamine (PE) (22.8%) and phosphatidylcholine (PC) (26.7%), with lesser amounts recovered in phosphatidyl-serine (PS) plus phosphatidylinositol (PI) (9.2%). By contrast, analysis of the phospholipid classes from prelabeled BCG-AM revealed that the mass of L(bis)PA as well as its (/sup 3/H)20:4 content was profoundly decreased while other BCG-AM phospholipids remained unchanged. When (/sup 3/H)20:4-labeled AM were stimulated with 1 ..mu..M 12-0-tetradecanoyl-phorbol-13-acetate (TPA), a loss of (/sup 3/H)20:4 was observed from L(bis)PA, PE, PC, and PS/PI with a corresponding increase in eicosanoid synthesis. BCG-AM exposed to either TPA or 3.8 ..mu..M Ca/sup +2/ ionophore A23187 liberated (/sup 3/H)20:4 solely from Pe and PC. BCG-AM, which exhibited depressed eicosanoid formation, consistently failed to deacylate (/sup 3/H)20:4 from L(bis)PA or PI. Their evidence suggests that the diminution of eicosanoid synthesis by BCG-AM may be due to the reduction of 20:4 contained within specific phospholipid pools, namely L(bis)PA.

  19. Influence of formulas with borage oil or borage oil plus fish oil on the arachidonic acid status in premature infants.

    PubMed

    Demmelmair, H; Feldl, F; Horváth, I; Niederland, T; Ruszinkó, V; Raederstorff, D; De Min, C; Muggli, R; Koletzko, B

    2001-06-01

    Several studies have reported that feeding gamma-linolenic acid (GLA) has resulted in no increase in arachidonic acid (AA) in newborns. This result was ascribed to the eicosapentaenoic acid (EPA)-rich fish oil used in these formulas. Docosahexaenoic acid (DHA) sources with only minor amounts of EPA are now available, thus the addition of GLA to infant formulas might be considered an alternative to AA supplementation. Sixty-six premature infants were randomized to feeding one of four formulas [ST: no GLA, no long-chain polyunsaturated fatty acids; BO: 0.6% GLA (borage oil); BO + FOLOW: 0.6% GLA, 0.3% DHA, 0.06% EPA; BO + FOHIGH: 0.6% GLA, 0.3% DHA, 0.2% EPA] or human milk (HM, nonrandomized) for 4 wk. Anthropometric measures and blood samples were obtained at study entry and after 14 and 28 d. There were no significant differences between groups in anthropometric measures, tocopherol, and retinol status at any of the studied time points. The AA content of plasma phospholipids was similar between groups at study start and decreased significantly until day 28 in all formulafed groups, but not in the breast-fed infants [ST: 6.6 +/- 0.2%, BO: 6.9 +/- 0.3%, BO + FOLOW: 6.9 +/- 0.4%, BO + FOHIGH: 6.7 +/- 0.2%, HM: 8.6 +/- 0.5%, where values are reported as mean +/- standard error; all formulas significantly different (P< 0.05) from HM]. There was no significant influence of GLA or fish oil addition to the diet. GLA had only a very limited effect on AA status which was too small to obtain satisfactory concentrations (concentrations similar to breast-fed babies) under the circumstances tested. The effect of GLA on AA is independent of the EPA and DHA content in the diet within the dose ranges studied. PMID:11485158

  20. Effects of Arachidonic Acid Supplementation on Acute Anabolic Signaling and Chronic Functional Performance and Body Composition Adaptations

    PubMed Central

    De Souza, Eduardo O.; Lowery, Ryan P.; Wilson, Jacob M.; Sharp, Matthew H.; Mobley, Christopher Brooks; Fox, Carlton D.; Lopez, Hector L.; Shields, Kevin A.; Rauch, Jacob T.; Healy, James C.; Thompson, Richard M.; Ormes, Jacob A.; Joy, Jordan M.; Roberts, Michael D.

    2016-01-01

    Background The primary purpose of this investigation was to examine the effects of arachidonic acid (ARA) supplementation on functional performance and body composition in trained males. In addition, we performed a secondary study looking at molecular responses of ARA supplementation following an acute exercise bout in rodents. Methods Thirty strength-trained males (age: 20.4 ± 2.1 yrs) were randomly divided into two groups: ARA or placebo (i.e. CTL). Then, both groups underwent an 8-week, 3-day per week, non-periodized training protocol. Quadriceps muscle thickness, whole-body composition scan (DEXA), muscle strength, and power were assessed at baseline and post-test. In the rodent model, male Wistar rats (~250 g, ~8 weeks old) were pre-fed with either ARA or water (CTL) for 8 days and were fed the final dose of ARA prior to being acutely strength trained via electrical stimulation on unilateral plantar flexions. A mixed muscle sample was removed from the exercised and non-exercised leg 3 hours post-exercise. Results Lean body mass (2.9%, p<0.0005), upper-body strength (8.7%, p<0.0001), and peak power (12.7%, p<0.0001) increased only in the ARA group. For the animal trial, GSK-β (Ser9) phosphorylation (p<0.001) independent of exercise and AMPK phosphorylation after exercise (p-AMPK less in ARA, p = 0.041) were different in ARA-fed versus CTL rats. Conclusions Our findings suggest that ARA supplementation can positively augment strength-training induced adaptations in resistance-trained males. However, chronic studies at the molecular level are required to further elucidate how ARA combined with strength training affect muscle adaptation. PMID:27182886

  1. Influence of formulas with borage oil or borage oil plus fish oil on the arachidonic acid status in premature infants.

    PubMed

    Demmelmair, H; Feldl, F; Horváth, I; Niederland, T; Ruszinkó, V; Raederstorff, D; De Min, C; Muggli, R; Koletzko, B

    2001-06-01

    Several studies have reported that feeding gamma-linolenic acid (GLA) has resulted in no increase in arachidonic acid (AA) in newborns. This result was ascribed to the eicosapentaenoic acid (EPA)-rich fish oil used in these formulas. Docosahexaenoic acid (DHA) sources with only minor amounts of EPA are now available, thus the addition of GLA to infant formulas might be considered an alternative to AA supplementation. Sixty-six premature infants were randomized to feeding one of four formulas [ST: no GLA, no long-chain polyunsaturated fatty acids; BO: 0.6% GLA (borage oil); BO + FOLOW: 0.6% GLA, 0.3% DHA, 0.06% EPA; BO + FOHIGH: 0.6% GLA, 0.3% DHA, 0.2% EPA] or human milk (HM, nonrandomized) for 4 wk. Anthropometric measures and blood samples were obtained at study entry and after 14 and 28 d. There were no significant differences between groups in anthropometric measures, tocopherol, and retinol status at any of the studied time points. The AA content of plasma phospholipids was similar between groups at study start and decreased significantly until day 28 in all formulafed groups, but not in the breast-fed infants [ST: 6.6 +/- 0.2%, BO: 6.9 +/- 0.3%, BO + FOLOW: 6.9 +/- 0.4%, BO + FOHIGH: 6.7 +/- 0.2%, HM: 8.6 +/- 0.5%, where values are reported as mean +/- standard error; all formulas significantly different (P< 0.05) from HM]. There was no significant influence of GLA or fish oil addition to the diet. GLA had only a very limited effect on AA status which was too small to obtain satisfactory concentrations (concentrations similar to breast-fed babies) under the circumstances tested. The effect of GLA on AA is independent of the EPA and DHA content in the diet within the dose ranges studied.

  2. [ANALYSIS OF ARACHIDONIC ACID RELATIVE CONTENT CHANGES IN ERYTHROCYTES AND PLATELETS PHOSPHOLIPIDS MEMBRANES FEATURES IN CORONARY HEART DISEASE WITH ATRIAL FIBRILLATION PATIENTS].

    PubMed

    Lizogub, V G; Zavalska, T V; Merkulova, I O; Bryuzgina, T S

    2015-01-01

    Erythrocytes and platelets phospholipid membranes fatty acid spectrum was detected in coronary heart disease and atrial fibrillation patients and in patients with coronary heart disease without atrial fibrillation. 87 patients were investigated. Significant decrease in the arachidonic acid relative content in coronary heart disease patients compared with healthy individuals was related. As well as a significant decrease in the arachidonic acid relative content in coronary heart disease and atrial fibrillation patients compared with coronary heart disease patients without atrial fibrillation was related too. These dates may indicate that decreasing relative content arachidonic acid can be possible pathogenetic link in the development of arrhythmias.

  3. Effect of Arachidonic Acid on the Rate of Oxygen Consumption in Isolated Cardiomyocytes from Intact Rats and Animals with Ischemic or Diabetic Injury to the Heart.

    PubMed

    Egorova, M V; Kutsykova, T V; Afanas'ev, S A; Popov, S V

    2015-12-01

    We studied the rate of oxygen consumption by isolated cardiomyocytes from intact rats and animals with experimental myocardial infarction or streptozotocin-induced diabetes mellitus. The measurements were performed in standard incubation medium under various conditions of oxygenation and after addition of arachidonic acid (20 μmol/liter). Under normoxic conditions, arachidonic acid improves respiration of cardiomyocytes from intact animals, but reduces this parameter in cells isolated from animals with pathologies. The intensity of O2 consumption by cardiomyocytes from intact rats and animals with pathologies was shown to decrease during hypoxia. Addition of arachidonic acid aggravated inhibition of respiration for cardiomyocytes from intact rats and specimens with myocardial infarction, but had no effect in diabetes mellitus. The effect of arachidonic acid on oxygen consumption rate is probably mediated by a nonspecific mechanism realized at the mitochondrial level.

  4. Chitosan-induced phospholipase A2 activation and arachidonic acid mobilization in P388D1 macrophages.

    PubMed

    Bianco, I D; Balsinde, J; Beltramo, D M; Castagna, L F; Landa, C A; Dennis, E A

    2000-01-28

    We have found that chitosan, a polysaccharide present in fungal cell walls, is able to activate macrophages for enhanced mobilization of arachidonic acid in a dose- and time-dependent manner. Studies aimed at identifying the intracellular effector(s) implicated in chitosan-induced arachidonate release revealed the involvement of the cytosolic Group IV phospholipase A2 (PLA2), as judged by the inhibitory effect of methyl arachidonoyl fluorophosphonate but not of bromoenol lactone. Interestingly, priming of the macrophages with lipopolysaccharide renders the cells more sensitive to a subsequent stimulation with chitosan, and this enhancement is totally blocked by the secretory PLA2 inhibitor 3-(3-acetamide)-1-benzyl-2-ethylindolyl-5-oxy-propanesulfonic acid (LY311727). Collectively, the results of this work establish chitosan as a novel macrophage-activating factor that elicits AA mobilization in P388D1 macrophages by a mechanism involving the participation of two distinct phospholipases A2. PMID:10682846

  5. Absorption and metabolism of ( sup 3 H)arachidonic and ( sup 14 C)linoleic acid in essential fatty acid-deficient rats

    SciTech Connect

    Hjelte, L.; Melin, T.; Nilsson, A.; Strandvik, B. )

    1990-07-01

    ({sup 3}H)arachidonic acid (20:4) and ({sup 14}C)linoleic acid (18:2) were fed in a triolein emulsion to essential fatty acid-deficient (EFAD) rats and to age-matched controls. Tissues were analyzed for radioactivity of different lipid classes after 1, 2, and 4 h. As in earlier studies, control rats retained more ({sup 3}H)20:4 than ({sup 14}C)18:2 in all organs except adipose tissue. In EFAD rats, recovery of ({sup 14}C)18:2 was increased in small intestine, liver, heart, and kidneys. In comparison to controls, EFAD rats retained much more ({sup 14}C)18:2 in phospholipids of these organs. The increase in the incorporation of both {sup 3}H and {sup 14}C into phosphatidylethanolamine was particularly pronounced. Another striking feature was the drastic increase in the retention after 4 h of {sup 14}C in cardiolipin, which is specifically located in the inner mitochondrial membrane. In contrast, incorporation of both {sup 3}H and {sup 14}C into phosphatidylinositol was decreased or unchanged in EFAD rats. Although fecal fat excretion was increased there was no evidence for a malabsorption or an increased retention in intestinal triacyglycerol of the radioactive fatty acids in EFAD rats. The proportion of ({sup 14}C)18:2 that had been converted to ({sup 14}C)20:4 was generally low but increased significantly with time in the liver and intestine of EFAD rats.

  6. Low Na intake suppresses expression of CYP2C23 and arachidonic acid-induced inhibition of ENaC.

    PubMed

    Sun, Peng; Lin, Dao-Hong; Wang, Tong; Babilonia, Elisa; Wang, Zhijian; Jin, Yan; Kemp, Rowena; Nasjletti, Alberto; Wang, Wen-Hui

    2006-12-01

    We previously demonstrated that arachidonic acid (AA) inhibits epithelial Na channels (ENaC) through the cytochrome P-450 (CYP) epoxygenase-dependent pathway (34). In the present study, we tested the hypothesis that low Na intake suppresses the expression of CYP2C23, which is mainly responsible for converting AA to epoxyeicosatrienoic acid (EET) in the kidney (11) and attenuates the AA-induced inhibition of ENaC. Immunostaining showed that CYP2C23 is expressed in the Tamm-Horsfall protein (THP)-positive and aquaporin 2 (AQP2)-positive tubules. This suggests that CYP2C23 is expressed in the thick ascending limb (TAL) and collecting duct (CD). Na restriction significantly suppressed the expression of CYP2C23 in the TAL and CD. Western blot also demonstrated that the expression of CYP2C23 in renal cortex and outer medulla diminished in rats on Na-deficient diet (Na-D) but increased in those on high-Na diet (4%). Moreover, the content of 11,12-epoxyeicosatrienoic acid (EET) decreased in the isolated cortical CD from rats on Na-D compared with those on a normal-Na diet (0.5%). Patch-clamp study showed that application of 15 microM AA inhibited the activity of ENaC by 77% in the CCD of rats on a Na-D for 3 days. However, the inhibitory effect of AA on ENaC was significantly attenuated in rats on Na-D for 14 days. Furthermore, inhibition of CYP epoxygenase with MS-PPOH increased the ENaC activity in the CCD of rats on a control Na diet. We also used microperfusion technique to examine the effect of MS-PPOH on Na transport in the distal nephron. Application of MS-PPOH significantly increased Na absorption in the distal nephron of control rats but had no significant effect on Na absorption in rats on Na-D for 14 days. We conclude that low Na intake downregulates the activity and expression of CYP2C23 and attenuates the inhibitory effect of AA on Na transport. PMID:16849695

  7. Exogenous arachidonic acid mediates permeability of human brain microvessel endothelial cells through prostaglandin E2 activation of EP3 and EP4 receptors.

    PubMed

    Dalvi, Siddhartha; Nguyen, Hieu H; On, Ngoc; Mitchell, Ryan W; Aukema, Harold M; Miller, Donald W; Hatch, Grant M

    2015-12-01

    The blood-brain barrier, formed by microvessel endothelial cells, is the restrictive barrier between the brain parenchyma and the circulating blood. Arachidonic acid (ARA; 5,8,11,14-cis-eicosatetraenoic acid) is a conditionally essential polyunsaturated fatty acid [20:4(n-6)] and is a major constituent of brain lipids. The current study examined the transport processes for ARA in confluent monolayers of human brain microvascular endothelial cells (HBMEC). Addition of radioactive ARA to the apical compartment of HBMEC cultured on Transwell(®) inserts resulted in rapid incorporation of radioactivity into the basolateral medium. Knock down of fatty acid transport proteins did not alter ARA passage into the basolateral medium as a result of the rapid generation of prostaglandin E2 (PGE2 ), an eicosanoid known to facilitate opening of the blood-brain barrier. Permeability following ARA or PGE2 exposure was confirmed by an increased movement of fluorescein-labeled dextran from apical to basolateral medium. ARA-mediated permeability was attenuated by specific cyclooxygenase-2 inhibitors. EP3 and EP4 receptor antagonists attenuated the ARA-mediated permeability of HBMEC. The results indicate that ARA increases permeability of HBMEC monolayers likely via increased production of PGE2 which acts upon EP3 and EP4 receptors to mediate permeability. These observations may explain the rapid influx of ARA into the brain previously observed upon plasma infusion with ARA. The blood-brain barrier, formed by microvessel endothelial cells, is a restrictive barrier between the brain parenchyma and the circulating blood. Radiolabeled arachidonic acid (ARA) movement across, and monolayer permeability in the presence of ARA, was examined in confluent monolayers of primary human brain microvessel endothelial cells (HBMECs) cultured on Transwell(®) plates. Incubation of HBMECs with ARA resulted in a rapid increase in HBMEC monolayer permeability. The mechanism was mediated, in part

  8. Systemic elevations of free radical oxidation products of arachidonic acid are associated with angiographic evidence of coronary artery disease.

    PubMed

    Shishehbor, Mehdi H; Zhang, Renliang; Medina, Hector; Brennan, Marie-Luise; Brennan, Danielle M; Ellis, Stephen G; Topol, Eric J; Hazen, Stanley L

    2006-12-01

    Oxidant stress is widely believed to participate in cardiovascular disease pathogenesis. However, progress in defining appropriate systemic antioxidant targeted therapies has been hindered by uncertainty in defining clinically relevant systemic oxidant stress measures. In a case control study, 50 subjects with CAD (>50% stenosis in one or more major coronary vessels) and 54 without CAD (<30% stenosis in all major coronary vessels) were tested. Plasma was isolated and stored under conditions designed to prevent artificial lipid peroxidation. Systemic levels of multiple (n=9) specific fatty acid oxidation products including individual hydroxyoctadecadienoic acids (HODEs), hydroxyeicosatetraenoic acids (HETEs), and F(2)-isoprostanes were simultaneously measured by high-performance liquid chromatography (HPLC) with on-line tandem mass spectrometry, along with traditional risk factors and C-reactive protein (CRP) levels. Of the markers monitored, only 9-HETE and F(2)-isoprostanes, both products of free radical-mediated arachidonic acid oxidation, were significantly elevated in patients with angiographically defined CAD (9-HETE, 8.7 +/- 4 vs 6.8 +/- 4 micromol/mol arachidonate, P = 0.011; and F(2)-isoprostanes, 9.4 +/- 5 vs 6.2 +/- 3 micromol/mol arachidonate, P < 0.001). In multivariable analyses with simultaneous adjustment for Framingham risk score and C-reactive protein, 9-HETE (4th quartile OR = 4.8, 95% CI=1.3 to 17.1; P = 0.016) and F(2)-isoprostanes (4th quartile OR=9.7, 95% CI=2.56 to 36.9; P < 0.001) remained strong and independent predictors of CAD risk. Systemic levels of 9-HETE and F(2)-isoprostanes are independently associated with angiographic evidence of CAD and appear superior to other specific oxidation products of arachidonic and linoleic acids as predictors of the presence of angiographically evident coronary artery disease.

  9. The effects of xanthoangelol E on arachidonic acid metabolism in the gastric antral mucosa and platelet of the rabbit.

    PubMed

    Fujita, T; Sakuma, S; Sumiya, T; Nishida, H; Fujimoto, Y; Baba, K; Kozawa, M

    1992-08-01

    The effects of a new chalcone derivative, xanthoangelol E, isolated from Angelica keiskei Koidzumi, on arachidonic acid metabolism in the gastric antral mucosa and platelet of the rabbit were examined. When gastric antral mucosal slices were incubated with xanthoangelol E (0.05-1.0 mM), there was no significant effect on the production of prostaglandin (PG) E2, PGF2 alpha and their metabolites. On the other hand, this compound inhibited effectively the production of thromboxane B2 and 12-hydroxy-5,8,10-heptadecatrienoic acid from exogenous arachidonic acid in platelets, and the concentration required for 50% inhibition (IC50) was approximately 5 microM. The formation of 12-hydroxy-5,8,10,14-eicosatetraenoic acid was also reduced by this drug (IC50, 50 microM). These results suggest that xanthoangelol E has the potential to modulate arachidonic acid metabolism in platelets and that this action may participate in some pharmacological effect of the plant.

  10. The biosynthesis of N-arachidonoyl dopamine (NADA), a putative endocannabinoid and endovanilloid, via conjugation of arachidonic acid with dopamine.

    PubMed

    Hu, Sherry Shu-Jung; Bradshaw, Heather B; Benton, Valery M; Chen, Jay Shih-Chieh; Huang, Susan M; Minassi, Alberto; Bisogno, Tiziana; Masuda, Kim; Tan, Bo; Roskoski, Robert; Cravatt, Benjamin F; Di Marzo, Vincenzo; Walker, J Michael

    2009-10-01

    N-arachidonoyl dopamine (NADA) is an endogenous ligand that activates the cannabinoid type 1 receptor and the transient receptor potential vanilloid type 1 channel. Two potential biosynthetic pathways for NADA have been proposed, though no conclusive evidence exists for either. The first is the direct conjugation of arachidonic acid with dopamine and the other is via metabolism of a putative N-arachidonoyl tyrosine (NA-tyrosine). In the present study we investigated these biosynthetic mechanisms and report that NADA synthesis requires TH in dopaminergic terminals; however, NA-tyrosine, which we identify here as an endogenous lipid, is not an intermediate. We show that NADA biosynthesis primarily occurs through an enzyme-mediated conjugation of arachidonic acid with dopamine. While this conjugation likely involves a complex of enzymes, our data suggest a direct involvement of fatty acid amide hydrolase in NADA biosynthesis either as a rate-limiting enzyme that liberates arachidonic acid from AEA, or as a conjugation enzyme, or both.

  11. Effect of heavy metal ions on neutrophil arachidonic acid metabolism and chemotaxis

    SciTech Connect

    Smith, D.M.; Turner, S.R.; Johnson, J.A.; Turner, R.A.

    1986-05-01

    Heavy metal ions can inhibit arachidonic acid (AA) metabolism, protect against ionophore cytotoxicity (ibid) and inhibit neutrophil chemotaxis. In this study they used Au/sup +3/, Zn/sup +2/, Cr/sup +3/, Mn/sup +2/, and Cu/sup +2/ as probes of the interrelationships among AA metabolism, ionophore-mediated cytotoxicity, and chemotaxis. Phospholipid deacylation was measured in ionophore-treated cells prelabeled with /sup 3/H-AA. Eicosanoid release from ionophore-treated cells was monitored both qualitatively by thin-layer chromatography of /sup 3/H-AA metabolities and quantitatively by radioimmunoassay. Cytoprotection was quantitated as ability to exclude trypan blue. Chemotaxis toward f-Met-Leu-Phe was measured by leading front analysis. The results imply that metal ions attenuate ionophore cytotoxicity by blocking phospholipid deacylation and eicosanoid production. In contrast to previous reports, the data obtained using Au/sup +3/ and Cu/sup +2/ demonstrates no correlation between AA metabolism and chemotaxis, suggesting that these 2 processes are not linked.

  12. Systematic Analysis Reveals that Cancer Mutations Converge on Deregulated Metabolism of Arachidonate and Xenobiotics.

    PubMed

    Gatto, Francesco; Schulze, Almut; Nielsen, Jens

    2016-07-19

    Mutations are the basis of the clonal evolution of most cancers. Nevertheless, a systematic analysis of whether mutations are selected in cancer because they lead to the deregulation of specific biological processes independent of the type of cancer is still lacking. In this study, we correlated the genome and transcriptome of 1,082 tumors. We found that nine commonly mutated genes correlated with substantial changes in gene expression, which primarily converged on metabolism. Further network analyses circumscribed the convergence to a network of reactions, termed AraX, that involves the glutathione- and oxygen-mediated metabolism of arachidonic acid and xenobiotics. In an independent cohort of 4,462 samples, all nine mutated genes were consistently correlated with the deregulation of AraX. Among all of the metabolic pathways, AraX deregulation represented the strongest predictor of patient survival. These findings suggest that oncogenic mutations drive a selection process that converges on the deregulation of the AraX network. PMID:27396332

  13. Relative incorporation of arachidonic and eicosapentaenoic acids into human platelet phospholipids

    SciTech Connect

    Weaver, B.J.; Holub, B.J.

    1985-11-01

    The incorporation of arachidonic acid (AA) as compared to eicosapentaenoic acid (EPA) into human platelet phospholipids was tested by incubating washed platelets with a known mixture of (3H)AA and (14C)EPA. Following incubation, the platelet lipids were extracted, the individual phospholipids--phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylinositol (PI) and phosphatidylethanolamine (PE)- were separated by thin layer chromatography, and their corresponding (3H)/(14C) ratios were determined. Based on a (3H)/(14C) ratio of unity for the substrate mixture, the PC, PS, PI and PE exhibited ratios of 0.55, 0.93, 1.12 and 0.74, respectively, which were significantly different from 1.00 in all instances except in the case of PS. These results indicate that PC and PE selectively incorporated EPA, while PI showed preference toward AA. These selectivities may account partly for the differing AA/EPA mass ratios that have been observed among the individual phospholipids of human subjects consuming fish oils.

  14. Prenatal arachidonic acid exposure and selected immune-related variables in childhood.

    PubMed

    Dirix, Chantal E H; Hogervorst, Janneke G F; Rump, Patrick; Hendriks, Johannes J E; Bruins, Maaike; Hornstra, Gerard

    2009-08-01

    Arachidonic acid (AA) is considered essential in fetal development and some of its metabolites are thought to be important mediators of the immune responses. Therefore, we studied whether prenatal exposure to AA is associated with some immune-related clinical conditions and plasma markers in childhood. In 280 children aged 7 years, atopy, lung function and plasma inflammation markers were measured and their relationships with early AA exposure were studied by linear and logistic regression analyses. AA exposure was deduced from AA concentrations in plasma phospholipids of the mothers collected at several time points during pregnancy and at delivery, and in umbilical cord plasma and arterial and venous wall phospholipids. In unadjusted regression analyses, significant positive associations were observed between maternal AA concentrations at 16 and 32 weeks of pregnancy (proxies for fetal AA exposure) and peak expiratory flow decline after maximal physical exercise and plasma fibrinogen concentrations of their children, respectively. However, after correction for relevant covariables, only trends remained. A significant negative relationship was observed between AA concentrations in cord plasma (reflecting prenatal AA exposure) and the average daily amplitude of peak expiratory flow at rest, which lost significance after appropriate adjustment. Because of these few, weak and inconsistent relationships, a major impact of early-life exposure to AA on atopy, lung function and selected plasma inflammation markers of children at 7 years of age seems unlikely.

  15. Prenatal arachidonic acid exposure and selected immune-related variables in childhood.

    PubMed

    Dirix, Chantal E H; Hogervorst, Janneke G F; Rump, Patrick; Hendriks, Johannes J E; Bruins, Maaike; Hornstra, Gerard

    2009-08-01

    Arachidonic acid (AA) is considered essential in fetal development and some of its metabolites are thought to be important mediators of the immune responses. Therefore, we studied whether prenatal exposure to AA is associated with some immune-related clinical conditions and plasma markers in childhood. In 280 children aged 7 years, atopy, lung function and plasma inflammation markers were measured and their relationships with early AA exposure were studied by linear and logistic regression analyses. AA exposure was deduced from AA concentrations in plasma phospholipids of the mothers collected at several time points during pregnancy and at delivery, and in umbilical cord plasma and arterial and venous wall phospholipids. In unadjusted regression analyses, significant positive associations were observed between maternal AA concentrations at 16 and 32 weeks of pregnancy (proxies for fetal AA exposure) and peak expiratory flow decline after maximal physical exercise and plasma fibrinogen concentrations of their children, respectively. However, after correction for relevant covariables, only trends remained. A significant negative relationship was observed between AA concentrations in cord plasma (reflecting prenatal AA exposure) and the average daily amplitude of peak expiratory flow at rest, which lost significance after appropriate adjustment. Because of these few, weak and inconsistent relationships, a major impact of early-life exposure to AA on atopy, lung function and selected plasma inflammation markers of children at 7 years of age seems unlikely. PMID:19173768

  16. Arachidonic acid mediates the formation of abundant alpha-helical multimers of alpha-synuclein

    NASA Astrophysics Data System (ADS)

    Iljina, Marija; Tosatto, Laura; Choi, Minee L.; Sang, Jason C.; Ye, Yu; Hughes, Craig D.; Bryant, Clare E.; Gandhi, Sonia; Klenerman, David

    2016-09-01

    The protein alpha-synuclein (αS) self-assembles into toxic beta-sheet aggregates in Parkinson’s disease, while it is proposed that αS forms soluble alpha-helical multimers in healthy neurons. Here, we have made αS multimers in vitro using arachidonic acid (ARA), one of the most abundant fatty acids in the brain, and characterized them by a combination of bulk experiments and single-molecule Fӧrster resonance energy transfer (sm-FRET) measurements. The data suggest that ARA-induced oligomers are alpha-helical, resistant to fibril formation, more prone to disaggregation, enzymatic digestion and degradation by the 26S proteasome, and lead to lower neuronal damage and reduced activation of microglia compared to the oligomers formed in the absence of ARA. These multimers can be formed at physiologically-relevant concentrations, and pathological mutants of αS form less multimers than wild-type αS. Our work provides strong biophysical evidence for the formation of alpha-helical multimers of αS in the presence of a biologically relevant fatty acid, which may have a protective role with respect to the generation of beta-sheet toxic structures during αS fibrillation.

  17. Unraveling the Genetic Basis of Aspirin Hypersensitivity in Asthma Beyond Arachidonate Pathways

    PubMed Central

    Park, Se-Min; Park, Jong Sook; Park, Hae-Sim

    2013-01-01

    Although aspirin-exacerbated respiratory disease (AERD) has attracted a great deal of attention because of its association with severe asthma, it remains widely under-diagnosed in the asthmatic population. Oral aspirin challenge is the best method of diagnosing AERD, but this is a time-consuming procedure with serious complications in some cases. Thus, development of non-invasive methods for easy diagnosis is necessary to prevent unexpected complications of aspirin use in susceptible patients. For the past decade, many studies have attempted to elucidate the genetic variants responsible for risk of AERD. Several approaches have been applied in these genetic studies. To date, a limited number of biologically plausible candidate genes in the arachidonate and immune and inflammatory pathways have been studied. Recently, a genome-wide association study was performed. In this review, the results of these studies are summarized, and their limitations discussed. In addition to the genetic variants, changes in methylation patterns on CpG sites have recently been identified in a target tissue of aspirin hypersensitivity. Finally, perspectives on application of new genomic technologies are introduced; these will aid our understanding of the genetic pathogenesis of aspirin hypersensitivity in asthma. PMID:24003382

  18. Arachidonic acid mediates the formation of abundant alpha-helical multimers of alpha-synuclein

    PubMed Central

    Iljina, Marija; Tosatto, Laura; Choi, Minee L.; Sang, Jason C.; Ye, Yu; Hughes, Craig D.; Bryant, Clare E.; Gandhi, Sonia; Klenerman, David

    2016-01-01

    The protein alpha-synuclein (αS) self-assembles into toxic beta-sheet aggregates in Parkinson’s disease, while it is proposed that αS forms soluble alpha-helical multimers in healthy neurons. Here, we have made αS multimers in vitro using arachidonic acid (ARA), one of the most abundant fatty acids in the brain, and characterized them by a combination of bulk experiments and single-molecule Fӧrster resonance energy transfer (sm-FRET) measurements. The data suggest that ARA-induced oligomers are alpha-helical, resistant to fibril formation, more prone to disaggregation, enzymatic digestion and degradation by the 26S proteasome, and lead to lower neuronal damage and reduced activation of microglia compared to the oligomers formed in the absence of ARA. These multimers can be formed at physiologically-relevant concentrations, and pathological mutants of αS form less multimers than wild-type αS. Our work provides strong biophysical evidence for the formation of alpha-helical multimers of αS in the presence of a biologically relevant fatty acid, which may have a protective role with respect to the generation of beta-sheet toxic structures during αS fibrillation. PMID:27671749

  19. Shuffling the cards in signal transduction: Calcium, arachidonic acid and mechanosensitivity

    PubMed Central

    Munaron, Luca

    2011-01-01

    Cell signaling is a very complex network of biochemical reactions triggered by a huge number of stimuli coming from the external medium. The function of any single signaling component depends not only on its own structure but also on its connections with other biomolecules. During prokaryotic-eukaryotic transition, the rearrangement of cell organization in terms of diffusional compartmentalization exerts a deep change in cell signaling functional potentiality. In this review I briefly introduce an intriguing ancient relationship between pathways involved in cell responses to chemical agonists (growth factors, nutrients, hormones) as well as to mechanical forces (stretch, osmotic changes). Some biomolecules (ion channels and enzymes) act as “hubs”, thanks to their ability to be directly or indirectly chemically/mechanically co-regulated. In particular calcium signaling machinery and arachidonic acid metabolism are very ancient networks, already present before eukaryotic appearance. A number of molecular “hubs”, including phospholipase A2 and some calcium channels, appear tightly interconnected in a cross regulation leading to the cellular response to chemical and mechanical stimulations. PMID:21537474

  20. Altered macrophage arachidonic acid metabolism induced by endotoxin tolerance: characterization and mechanisms

    SciTech Connect

    Rogers, T.S.

    1986-01-01

    Altered macrophage arachidonic acid (AA) metabolism may play a role in endotoxic shock and the phenomenon of endotoxin tolerance induced by repeated injections of endotoxin. Studies were initiated to characterize both lipoxygenase and cyclooxygenase metabolite formation by endotoxin tolerant and non-tolerant macrophages in response to 4 different stimuli, i.e., endotoxin, glucan, zymosan, and the calcium ionophore A23187. In contrast to previous reports of decreased prostaglandin synthesis by tolerant macrophages, A23187-stimulated immunoreactive (i) leukotriene (LT) C/sub 4/D/sub 4/ and prostaglandin (PG) E/sub 2/ production by tolerant cells was greater than that by non-tolerant controls (p <0.001). However, A23187-stimulated i6-keto PGF/sub 1a/ levels were lower in tolerant macrophages compared to controls (P < 0.05). iL TC/sub 4/D/sub 4/ production was not significantly stimulated by endotoxin or glucan, but was stimulated by zymosan in non-tolerant cells. Synthesis of iLTB/sub 4/ by control macrophages was stimulated by endotoxin (p <0.01). The effect of tolerance on factors that affect AA release was investigated by measuring /sup 14/C-AA incorporation and release and phospholipase A/sub 2/ activity

  1. Epoxygenase metabolites of arachidonic acid inhibit vasopressin response in toad bladder

    SciTech Connect

    Schlondorff, D.; Petty, E.; Oates, J.A.; Jacoby, M.; Levine, S.D. Vanderbilt Univ., Nashville, TN )

    1987-09-01

    In addition to cyclooxygenase and lipoxygenase pathways, the kidney can also metabolize arachidonic acid by a NADPH-dependent cytochrome P-450 enzyme to epoxyeicosatrienoic acids (EETs); furthermore, 5,6-EET has been shown to alter electrolyte transport across isolated renal tubules. The authors examined the effects of three ({sup 14}C-labeled)-EETs (5,6-, 11,12-, and 14,15-EET) on osmotic water flow across toad urinary bladder. All three EETs reversibly inhibited vasopressin-stimulated osmotic water flow with 5,6- and 11,12-EET being the most potent. The effects appeared to be independent of prostaglandins EETs inhibited the water flow response to forskolin but not the response to adenosine 3{prime},5{prime}-cyclic monophosphate (cAMP) or 8-BrcAMP, consistent with an effect on cAMP generation. To determine whether these effects were due to the EETs or to products of their metabolism, they examined the effects of their vicinal diol hydrolysis products, the dihydroxyeicosatrienoic acids. Nonenzymatic conversion of labeled 5,6-EET to its vicinal diol occurred rapidly in the buffer, whereas 11,12-EET was hydrolyzed in a saturable manner only when incubated in the presence of bladder tissue. The dihydroxyeicosatrienoic acids formed inhibited water flow in a manner paralleling that of the EETs. The data support the hypothesis that EETs and their physiologically active dihydroxyeicosatrienoic acid metabolites inhibit vasopressin-stimulated water flow predominantly via inhibition of adenylate cyclase.

  2. Accumulation of arachidonic acid-containing phosphatidylinositol at the outer edge of colorectal cancer

    PubMed Central

    Hiraide, Takanori; Ikegami, Koji; Sakaguchi, Takanori; Morita, Yoshifumi; Hayasaka, Takahiro; Masaki, Noritaka; Waki, Michihiko; Sugiyama, Eiji; Shinriki, Satoru; Takeda, Makoto; Shibasaki, Yasushi; Miyazaki, Shinichiro; Kikuchi, Hirotoshi; Okuyama, Hiroaki; Inoue, Masahiro; Setou, Mitsutoshi; Konno, Hiroyuki

    2016-01-01

    Accumulating evidence indicates that cancer cells show specific alterations in phospholipid metabolism that contribute to tumour progression in several types of cancer, including colorectal cancer. Questions still remain as to what lipids characterize the outer edge of cancer tissues and whether those cancer outer edge-specific lipid compositions emerge autonomously in cancer cells. Cancer tissue-originated spheroids (CTOSs) that are composed of pure primary cancer cells have been developed. In this study, we aimed to seek out the cancer cell-autonomous acquisition of cancer outer edge-characterizing lipids in colorectal cancer by analysing phospholipids in CTOSs derived from colorectal cancer patients with matrix-assisted laser desorption/ionization (MALDI)-imaging mass spectrometry (IMS). A signal at m/z 885.5 in negative ion mode was detected specifically at the surface regions. The signal was identified as an arachidonic acid (AA)-containing phosphatidylinositol (PI), PI(18:0/20:4), by tandem mass spectrometry analysis. Quantitative analysis revealed that the amount of PI(18:0/20:4) in the surface region of CTOSs was two-fold higher than that in the medial region. Finally, PI(18:0/20:4) was enriched at the cancer cells/stromal interface in colorectal cancer patients. These data imply a possible importance of AA-containing PI for colorectal cancer progression, and suggest cells expressing AA-containing PI as potential targets for anti-cancer therapy. PMID:27435310

  3. LPIAT1 regulates arachidonic acid content in phosphatidylinositol and is required for cortical lamination in mice

    PubMed Central

    Lee, Hyeon-Cheol; Inoue, Takao; Sasaki, Junko; Kubo, Takuya; Matsuda, Shinji; Nakasaki, Yasuko; Hattori, Mitsuharu; Tanaka, Fumiharu; Udagawa, Osamu; Kono, Nozomu; Itoh, Toshiki; Ogiso, Hideo; Taguchi, Ryo; Arita, Makoto; Sasaki, Takehiko; Arai, Hiroyuki

    2012-01-01

    Dietary arachidonic acid (AA) has roles in growth, neuronal development, and cognitive function in infants. AA is remarkably enriched in phosphatidylinositol (PI), an important constituent of biological membranes in mammals; however, the physiological significance of AA-containing PI remains unknown. In an RNA interference–based genetic screen using Caenorhabditis elegans, we recently cloned mboa-7 as an acyltransferase that selectively incorporates AA into PI. Here we show that lysophosphatidylinositol acyltransferase 1 (LPIAT1, also known as MBOAT7), the closest mammalian homologue, plays a crucial role in brain development in mice. Lpiat1−/− mice show almost no LPIAT activity with arachidonoyl-CoA as an acyl donor and show reduced AA contents in PI and PI phosphates. Lpiat1−/− mice die within a month and show atrophy of the cerebral cortex and hippocampus. Immunohistochemical analysis reveals disordered cortical lamination and delayed neuronal migration in the cortex of E18.5 Lpiat1−/− mice. LPIAT1 deficiency also causes disordered neuronal processes in the cortex and reduced neurite outgrowth in vitro. Taken together, these results demonstrate that AA-containing PI/PI phosphates play an important role in normal cortical lamination during brain development in mice. PMID:23097495

  4. Myogenic and metabolic feedback in cerebral autoregulation: Putative involvement of arachidonic acid-dependent pathways.

    PubMed

    Berg, Ronan M G

    2016-07-01

    The present paper presents a mechanistic model of cerebral autoregulation, in which the dual effects of the arachidonic acid metabolites 20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatrienoic acids (EETs) on vascular smooth muscle mediate the cerebrovascular adjustments to a change in cerebral perfusion pressure (CPP). 20-HETE signalling in vascular smooth muscle mediates myogenic feedback to changes in vessel wall stretch, which may be modulated by metabolic feedback through EETs released from astrocytes and endothelial cells in response to changes in brain tissue oxygen tension. The metabolic feedback pathway is much faster than 20-HETE-dependent myogenic feedback, and the former thus initiates the cerebral autoregulatory response, while myogenic feedback comprises a relatively slower mechanism that functions to set the basal cerebrovascular tone. Therefore, assessments of dynamic cerebral autoregulation, which may provide information on the response time of the cerebrovasculature, may specifically be used to yield information on metabolic feedback mechanisms, while data based on assessments of static cerebral autoregulation represent the integrated functionality of myogenic and metabolic feedback. PMID:27241246

  5. Arachidonic acid accumulates in the stromal macrophages during thymus involution in diabetes.

    PubMed

    Gruia, Alexandra T; Barbu-Tudoran, Lucian; Mic, Ani A; Ordodi, Valentin L; Paunescu, Virgil; Mic, Felix A

    2011-07-01

    Diabetes is a debilitating disease with chronic evolution that affects many tissues and organs over its course. Thymus is an organ that is affected early after the onset of diabetes, gradually involuting until it loses most of its thymocyte populations. We show evidence of accumulating free fatty acids with generation of eicosanoids in the diabetic thymus and we present a possible mechanism for the involution of the organ during the disease. Young rats were injected with streptozotocin and their thymuses examined for cell death by flow cytometry and TUNEL reaction. Accumulation of lipids in the diabetic thymus was investigated by histology and electron microscopy. The identity and quantitation of accumulating lipids was done with gas chromatography-mass spectrometry and liquid chromatography. The expression and dynamics of the enzymes were monitored via immunohistochemistry. Diabetes causes thymus involution by elevating the thymocyte apoptosis. Exposure of thymocytes to elevated concentration of glucose causes apoptosis. After the onset of diabetes, there is a gradual accumulation of free fatty acids in the stromal macrophages including arachidonic acid, the substrate for eicosanoids. The eicosanoids do not cause thymocyte apoptosis but administration of a cyclooxygenase inhibitor reduces the staining for ED1, a macrophage marker whose intensity correlates with phagocytic activity. Diabetes causes thymus involution that is accompanied by accumulation of free fatty acids in the thymic macrophages. Excess glucose is able to induce thymocyte apoptosis but eicosanoids are involved in the chemoattraction of macrophage to remove the dead thymocytes.

  6. Extracts from Tribulus species may modulate platelet adhesion by interfering with arachidonic acid metabolism.

    PubMed

    Olas, Beata; Hamed, Arafa I; Oleszek, Wieslaw; Stochmal, Anna

    2015-01-01

    The present work was designed to study the effects of crude extracts from Tribulus pterocarpus, T. pentandrus and T. parvispinus on selected biological functions of human blood platelets in vitro. Platelet suspensions were pre-incubated with extracts from aerial parts of T. pterocarpus, T. pentandrus and T. parvispinus, at the final concentrations of 0.5, 5 and 50 µg/ml. Then, for platelet activation thrombin, was used. The effects of crude extracts from T. pterocarpus, T. pentandrus and T. parvispinus on adhesion of blood platelets to collagen were determined by method according to Tuszynski and Murphy. Arachidonic acid metabolism was measured by the level of thiobarbituric acid reactive substances (TBARS). In these studies we also compared the action of tested crude plant extracts with the effects of the polyphenolic fraction isolated from aerial parts of T. pterocarpus, which has antiplatelet and antioxidative properties. The performed assays demonstrated that the tested crude extract from T. pterocarpus and the phenolic fraction from T. pterocarpus might influence the platelet functions in vitro. The inhibitory, concentration-dependent effects of this tested extract and its phenolic fraction on adhesion of resting platelets and thrombin - stimulated platelets to collagen was found. We also observed that the crude extract from T. pterocarpus, like the polyphenolic fraction from T. pterocarpus reduced TBARS production in blood platelets. In the comparative studies, the tested crude extract from T. pterocarpus was not found to be more effective antiplatelet factor, than the polyphenolic fraction from this plant. The results obtained suggest that T. pterocarpus may be a promising source of natural compounds, valuable in the prevention of the enhanced activity of blood platelets in numerous cardiovascular diseases.

  7. Culture media optimization of Porphyridium purpureum: production potential of biomass, total lipids, arachidonic and eicosapentaenoic acid.

    PubMed

    Kavitha, Mysore Doddaiah; Kathiresan, Shanmugam; Bhattacharya, Sila; Sarada, Ravi

    2016-05-01

    Porphyridium purpureum a red marine microalga is known for phycobiliproteins (PB), polyunsaturated fatty acids and sulphated exopolysaccharides. In the present study, effects of media constituents for the production of different polyunsaturated fatty acids from P. purpureum were considered using a response surface methodology (RSM). A second order polynomial was used to predict the response functions in terms of the independent variables such as the concentrations of sodium chloride, magnesium sulphate, sodium nitrate and potassium dihydrogen phosphate. The response functions were production of biomass yield, total lipid and polyunsaturated fatty acids like arachidonic acid (AA 20:4) and eicosapentaenoic acid (EPA 20:5). Results corroborated that maximum Biomass (0.95 gL(-1)) yield was at the concentrations of sodium chloride (14.89 gL(-1)), magnesium sulfate (3.93 gL(-1)) and sodium nitrate (0.96 gL(-1)) and potassium dihydrogen phosphate (0.09 gL(-1)). Optimum total lipid (17.9 % w/w) and EPA (34.6 % w/w) content was at the concentrations of sodium chloride (29.98 gL(-1)), magnesium sulfate (9.34 gL(-1)) and sodium nitrate (1.86 gL(-1)). Variation in concentration of potassium dihydrogen phosphate for both lipid (0.01gL(-1)) and EPA content (0.20 gL(-1)) was observed. The optimum conditions for biomass, total lipid, AA and EPA varied indicating their batch mode of growth and interaction effect of the salt.

  8. [Cyclooxygenase inhibitors in some dietary vegetables inhibit platelet aggregation function induced by arachidonic acid].

    PubMed

    Wang, Xin-Hua; Shao, Dong-Hua; Liang, Guo-Wei; Zhang, Ru; Xin, Qin; Zhang, Tao; Cao, Qing-Yun

    2011-10-01

    The study was purposed to investigate whether the cyclooxygenase inhibitors from some dietary vegetables can inhibit platelet aggregation function by the arachidonic acid (AA). The vegetable juice was mixed with platelet rich plasma (PRP), and asprin was used as positive control. The maximum ratio of platelet aggregation induced by AA was measured on the aggregometer; heme and cyclooxygenase-1 (COX(1)) or cyclooxygenase-2 (COX(2)) were added to test tubes containing COX reaction buffer, the mixture was vortex-mixed and exposed to aspirin or vegetable juice, followed by addition of AA and then hydrochloric acid (1 mol/L) was added to stop the COX reaction, followed by chemical reduction with stannous chloride solution. The concentration of COX inhibitors was detected by the enzyme immunoassay kit; vegetable juice (aspirin as positive control) was mixed with whole blood, which was followed by the addition of AA, and then the reaction was stopped by adding indomethacin, centrifuged, then the supernatant was collected, and the plasma thromboxane B(2) (TXB(2)) was measured by radioimmunoassay. The results showed that spinach juice, garlic bolt juice, blanched garlic leave juice and Chinese leek juice could inhibit by 80% human platelet aggregation induced by AA. 4 kinds of vegetables were all found a certain amount of cyclooxygenase inhibitors, which COX(1) and COX(2) inhibitor concentrations of spinach were higher than that of aspirin; 4 vegetable juice could significantly reduce the human plasma concentrations of TXB(2) induced by AA (p < 0.05). It is concluded that 4 kinds of raw vegetables containing cyclooxygenase inhibitors inhibit the production of TXA(2) and thus hinder platelet aggregation. Raw spinach, garlic bolt, blanched garlic and chinese leek inhibit significantly AA-induced human platelet aggregation in vitro. 4 kinds of vegetables may have a good potential perspective of anti-platelet aggregation therapy or prevention of thrombosis.

  9. Effects of a low birthweight infant formula containing human milk levels of docosahexaenoic and arachidonic acids.

    PubMed

    Koletzko, B; Edenhofer, S; Lipowsky, G; Reinhardt, D

    1995-08-01

    Long-chain (LC) polyunsaturated fatty acids (PUFA) (LCP) are considered conditionally essential nutrients for low birth weight infants (LBWI). Therefore, enrichment of LBWI formulae with metabolites both linoleic (omega-6) and alpha-linolenic (omega-3) acids at levels typical for human milk has been recommended. However, previous feeding trials with LCP-enriched formulae evaluated only a dietary supplementation with omega-3 LCP from fish oils alone or with both omega-3 and omega-6 LCP at levels considerably lower than usual human milk contents. We studied the effects of an LBWI formula providing the major omega-3 and omega-6 LCP, docosahexaenoic and arachidonic acids, in amounts similar to those in average human milk. Twenty-seven LBWIs were enrolled in this study when they tolerated full enteral feeding (> or = 130 ml milk/kg/day). Infants either received their own mother's milk (n = 8, birthweight 1218 +/- 146 g, gestational age 30.2 +/- 1.5 weeks, mean +/- SD) fortified with protein and minerals (FM-85, Nestle Ag, Munchen, Germany; dosage 5 g/100 ml milk) or were randomly assigned to blinded batches of an LBWI formula (Prematil, Milupa AG, Friedrichsdorf, Germany) without LCP (n = 10, 1280 +/- 229 g, 31.1 +/- 3.1 weeks) or with LCP (n = 9, 1253 +/- 334 g, 30.4 +/- 3.3 wks.). During the study period of 21 days, the three feeding groups did not differ in growth and feeding tolerances as assessed by occurrence of gastric residuals, spitting, or abdominal distention; however, firms stools were noted more frequently in the two formula groups.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Eugenol: a dual inhibitor of platelet-activating factor and arachidonic acid metabolism.

    PubMed

    Saeed, S A; Simjee, R U; Shamim, G; Gilani, A H

    1995-07-01

    Eugenol is an active principal and responsible for several pharmacological activities of clove oil. We studied the effects of eugenol on human platelet aggregation, arachidonic acid (AA) and platelet-activating factor (PAF) metabolism and in vivo effects on AA and PAF-induced shock in rabbits. Eugenol strongly inhibited PAF-induced platelet aggregation with lesser effect against AA and collegen. The IC(50) values were against AA: 31 ± 0.5; collagen: 64 ± 0.7 and PAF 7 ± 0.2 μM (n=9) respectively. In addition, eugenol stimulated PAF-acetylhydrolase activity suggesting that inhibition of PAF could be due to its inactivation to lyso-PAF. Pretreatment of rabbits with eugenol (50-100 mg/kg) prevented the lethal effects of intravenous PAF (11 μgg/kg) or AA (2 mg/kg) in a dose-dependent fashion. The protective effects of eugenol in the rabbits, however, were more pronounced against PAF-induced mortality (100% protection). In addition, eugenol also inhibited AA metabolism via cyclooxygenase and lipoxygenase pathways in human platelets. Both the production of thromboxane-A(2) and 12-hydroxy-eicosatetraenoic acid was inhibited by eugenol in a concentration-related manner (30-120 μM). In vivo, eugenol (50-100 mg/kg; i.p.) inhibited carrageenan-induced rat paw oedema (P < 0.001). In this test, eugenol was 5 times more potent than aspirin. These results provide evidence that eugenol acts as a dual antagonist of AA and PAF. PMID:23196096

  11. Culture media optimization of Porphyridium purpureum: production potential of biomass, total lipids, arachidonic and eicosapentaenoic acid.

    PubMed

    Kavitha, Mysore Doddaiah; Kathiresan, Shanmugam; Bhattacharya, Sila; Sarada, Ravi

    2016-05-01

    Porphyridium purpureum a red marine microalga is known for phycobiliproteins (PB), polyunsaturated fatty acids and sulphated exopolysaccharides. In the present study, effects of media constituents for the production of different polyunsaturated fatty acids from P. purpureum were considered using a response surface methodology (RSM). A second order polynomial was used to predict the response functions in terms of the independent variables such as the concentrations of sodium chloride, magnesium sulphate, sodium nitrate and potassium dihydrogen phosphate. The response functions were production of biomass yield, total lipid and polyunsaturated fatty acids like arachidonic acid (AA 20:4) and eicosapentaenoic acid (EPA 20:5). Results corroborated that maximum Biomass (0.95 gL(-1)) yield was at the concentrations of sodium chloride (14.89 gL(-1)), magnesium sulfate (3.93 gL(-1)) and sodium nitrate (0.96 gL(-1)) and potassium dihydrogen phosphate (0.09 gL(-1)). Optimum total lipid (17.9 % w/w) and EPA (34.6 % w/w) content was at the concentrations of sodium chloride (29.98 gL(-1)), magnesium sulfate (9.34 gL(-1)) and sodium nitrate (1.86 gL(-1)). Variation in concentration of potassium dihydrogen phosphate for both lipid (0.01gL(-1)) and EPA content (0.20 gL(-1)) was observed. The optimum conditions for biomass, total lipid, AA and EPA varied indicating their batch mode of growth and interaction effect of the salt. PMID:27407193

  12. Prostaglandin E2 and the protein kinase A pathway mediate arachidonic acid induction of c-fos in human prostate cancer cells

    NASA Technical Reports Server (NTRS)

    Chen, Y.; Hughes-Fulford, M.

    2000-01-01

    Arachidonic acid (AA) is the precursor for prostaglandin E2 (PGE2) synthesis and increases growth of prostate cancer cells. To further elucidate the mechanisms involved in AA-induced prostate cell growth, induction of c-fos expression by AA was investigated in a human prostate cancer cell line, PC-3. c-fos mRNA was induced shortly after addition of AA, along with a remarkable increase in PGE2 production. c-fos expression and PGE2 production induced by AA was blocked by a cyclo-oxygenase inhibitor, flurbiprofen, suggesting that PGE2 mediated c-fos induction. Protein kinase A (PKA) inhibitor H-89 abolished induction of c-fos expression by AA, and partially inhibited PGE2 production. Protein kinase C (PKC) inhibitor GF109203X had no significant effect on c-fos expression or PGE2 production. Expression of prostaglandin (EP) receptors, which mediate signal transduction from PGE2 to the cells, was examined by reverse transcription polymerase chain reaction in several human prostate cell lines. EP4 and EP2, which are coupled to the PKA signalling pathway, were expressed in all cells tested. Expression of EP1, which activates the PKC pathway, was not detected. The current study showed that induction of the immediate early gene c-fos by AA is mediated by PGE2, which activates the PKA pathway via the EP2/4 receptor in the PC-3 cells.

  13. Organochlorine insecticides induce NADPH oxidase-dependent reactive oxygen species in human monocytic cells via phospholipase A2/arachidonic acid.

    PubMed

    Mangum, Lee C; Borazjani, Abdolsamad; Stokes, John V; Matthews, Anberitha T; Lee, Jung Hwa; Chambers, Janice E; Ross, Matthew K

    2015-04-20

    ) levels and enhanced p47(phox) membrane localization compared to that in vehicle-treated cells. p47(phox) is a cytosolic regulatory subunit of Nox, and its phosphorylation and translocation to the NOX2 catalytic subunit in membranes is a requisite step for Nox assembly and activation. Dieldrin and trans-nonachlor treatments of monocytes also resulted in marked increases in arachidonic acid (AA) and eicosanoid production, which could be abrogated by the phospholipase A2 (PLA2) inhibitor arachidonoyltrifluoromethyl ketone (ATK) but not by calcium-independent PLA2 inhibitor bromoenol lactone. This suggested that cytosolic PLA2 plays a crucial role in the induction of Nox activity by increasing the intracellular pool of AA that activates protein kinase C, which phosphorylates p47(phox). In addition, ATK also blocked OC-induced p47(phox) serine phosphorylation and attenuated ROS levels, which further supports the notion that the AA pool liberated by cytosolic PLA2 is responsible for Nox activation. Together, the results suggest that trans-nonachlor and dieldrin are capable of increasing intracellular superoxide levels via a Nox-dependent mechanism that relies on elevated intracellular AA levels. These findings are significant because chronic activation of monocytes by environmental toxicants might contribute to pathogenic oxidative stress and inflammation. PMID:25633958

  14. Anti-Inflammation Effects and Potential Mechanism of Saikosaponins by Regulating Nicotinate and Nicotinamide Metabolism and Arachidonic Acid Metabolism.

    PubMed

    Ma, Yu; Bao, Yongrui; Wang, Shuai; Li, Tianjiao; Chang, Xin; Yang, Guanlin; Meng, Xiansheng

    2016-08-01

    Inflammation is an important immune response; however, excessive inflammation causes severe tissue damages and secondary inflammatory injuries. The long-term and ongoing uses of routinely used drugs such as non-steroidal anti-inflammatory drugs (NSAIDS) are associated with serious adverse reactions, and not all patients have a well response to them. Consequently, therapeutic products with more safer and less adverse reaction are constantly being sought. Radix Bupleuri, a well-known traditional Chinese medicine (TCM), has been reported to have anti-inflammatory effects. However, saikosaponins (SS) as the main pharmacodynamic active ingredient, their pharmacological effects and action mechanism in anti-inflammation have not been reported frequently. This study aimed to explore the anti-inflammatory activity of SS and clarify the potential mechanism in acute inflammatory mice induced by subcutaneous injection of formalin in hind paws. Paw edema was detected as an index to evaluate the anti-inflammatory efficacy of SS. Then, a metabolomic method was used to investigate the changed metabolites and potential mechanism of SS. Metabolite profiling was performed by high-performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF-MS). The detection and identification of the changed metabolites were systematically analyzed by multivariate data and pathway analysis. As a result, 12 different potential biomarkers associated with SS in anti-inflammation were identified, including nicotinate, niacinamide, arachidonic acid (AA), and 20-carboxy-leukotriene B4, which are associated with nicotinate and nicotinamide metabolism and arachidonic acid metabolism. The expression levels of biomarkers were effectively modulated towards the normal range by SS. It indicated that SS show their effective anti-inflammatory effects through regulating nicotinate and nicotinamide metabolism and arachidonic acid metabolism. PMID:27251379

  15. Deficits in docosahexaenoic acid and associated elevations in the metabolism of arachidonic acid and saturated fatty acids in the postmortem orbitofrontal cortex of patients with bipolar disorder

    PubMed Central

    McNamara, Robert K.; Jandacek, Ronald; Rider, Therese; Tso, Patrick; Stanford, Kevin E.; Hahn, Chang-Gyu; Richtand, Neil M.

    2008-01-01

    Previous antemortem and postmortem tissue fatty acid composition studies have observed significant deficits in the omega-3 fatty acid docosahexaenoic acid (DHA, 22:6n-3) in red blood cell (RBC) and postmortem cortical membranes of patients with unipolar depression. In the present we determined the fatty acid composition of postmortem orbitofrontal cortex (OFC, Brodmann area 10) of patients with bipolar disorder (n=18) and age-matched normal controls (n=19) by gas chromatography. After correction for multiple comparisons, DHA (-24%), arachidonic acid (-14%), and stearic acid (C18:0)(-4.5%) compositions were significantly lower, and cis-vaccenic acid (18:1n-7)(+12.5%) composition significantly higher, in the OFC of bipolar patients relative to normal controls. Based on metabolite:precursor ratios, significant elevations in arachidonic acid, stearic acid, and palmitic acid conversion/metabolism were observed in the OFC of bipolar patients, and were inversely correlated with DHA composition. Deficits in OFC DHA and arachidonic acid composition, and elevations in arachidonic acid metabolism, were numerically (but not significantly) greater in drug-free bipolar patients relative to patients treated with mood-stabilizer or antipsychotic medications. OFC DHA and arachidonic acid deficits were greater in patients plus normal controls with high versus low alcohol abuse severity. These results add to a growing body of evidence implicating omega-3 fatty acid deficiency as well as the OFC in the pathoaetiology of bipolar disorder. PMID:18715653

  16. Levels of linoleate and arachidonate in red blood cells of healthy individuals and patients with multiple sclerosis.

    PubMed Central

    Homa, S T; Belin, J; Smith, A D; Monro, J A; Zilkha, K J

    1980-01-01

    The major fatty acids were measured in total lipid extracts of red blood cells from 23 control subjects and 31 patients with multiple sclerosis. In the healthy control subjects an inverse correlation (r = -0.83) was found between the percentages of linoleate and arachidonate. In the patients such an inverse correlation was not found. The results suggest an abnormality in the red blood cells of patients with multiple sclerosis specifically with regard to the regulation of the relative amounts of unsaturated fatty acids, and this has implications for the possible treatment of multiple sclerosis with dietary supplements. PMID:7359147

  17. Oxymetazoline inhibits proinflammatory reactions: effect on arachidonic acid-derived metabolites.

    PubMed

    Beck-Speier, Ingrid; Dayal, Niru; Karg, Erwin; Maier, Konrad L; Schumann, Gabriele; Semmler, Manuela; Koelsch, Stephan M

    2006-02-01

    The nasal decongestant oxymetazoline effectively reduces rhinitis symptoms. We hypothesized that oxymetazoline affects arachidonic acid-derived metabolites concerning inflammatory and oxidative stress-dependent reactions. The ability of oxymetazoline to model pro- and anti-inflammatory and oxidative stress responses was evaluated in cell-free systems, including 5-lipoxygenase (5-LO) as proinflammatory, 15-lipoxygenase (15-LO) as anti-inflammatory enzymes, and oxidation of methionine by agglomerates of ultrafine carbon particles (UCPs), indicating oxidative stress. In a cellular approach using canine alveolar macrophages (AMs), the impact of oxymetazoline on phospholipase A(2) (PLA(2)) activity, respiratory burst and synthesis of prostaglandin E(2) (PGE(2)), 15(S)-hydroxy-eicosatetraenoic acid (15-HETE), leukotriene B(4) (LTB(4)), and 8-isoprostane was measured in the absence and presence of UCP or opsonized zymosan as particulate stimulants. In cell-free systems, oxymetazoline (0.4-1 mM) inhibited 5-LO but not 15-LO activity and did not alter UCP-induced oxidation of methionine. In AMs, oxymetazoline induced PLA(2) activity and 15-HETE at 1 mM, enhanced PGE(2) at 0.1 mM, strongly inhibited LTB(4) and respiratory burst at 0.4/0.1 mM (p < 0.05), but did not affect 8-isoprostane formation. In contrast, oxymetazoline did not alter UCP-induced PLA(2) activity and PGE(2) and 15-HETE formation in AMs but inhibited UCP-induced LTB(4) formation and respiratory burst at 0.1 mM and 8-isoprostane formation at 0.001 mM (p < 0.05). In opsonized zymosan-stimulated AMs, oxymetazoline inhibited LTB(4) formation and respiratory burst at 0.1 mM (p < 0.05). In conclusion, in canine AMs, oxymetazoline suppressed proinflammatory reactions including 5-LO activity, LTB(4) formation, and respiratory burst and prevented particle-induced oxidative stress, whereas PLA(2) activity and synthesis of immune-modulating PGE(2) and 15-HETE were not affected.

  18. Individual variation and intraclass correlation in arachidonic acid and eicosapentaenoic acid in chicken muscle

    PubMed Central

    2010-01-01

    Chicken meat with reduced concentration of arachidonic acid (AA) and reduced ratio between omega-6 and omega-3 fatty acids has potential health benefits because a reduction in AA intake dampens prostanoid signaling, and the proportion between omega-6 and omega-3 fatty acids is too high in our diet. Analyses for fatty acid determination are expensive, and finding the optimal number of analyses to give reliable results is a challenge. The objective of the present study was i) to analyse the intraclass correlation of different fatty acids in five meat samples, of one gram each, within the same chicken thigh, and ii) to study individual variations in the concentrations of a range of fatty acids and the ratio between omega-6 and omega-3 fatty acid concentrations among fifteen chickens. Fifteen newly hatched broilers were fed a wheat-based diet containing 4% rapeseed oil and 1% linseed oil for three weeks. Five muscle samples from the mid location of the thigh of each chicken were analysed for fatty acid composition. The intraclass correlation (sample correlation within the same animal) was 0.85-0.98 for the ratios of total omega-6 to total omega-3 fatty acids and of AA to eicosapentaenoic acid (EPA). This indicates that when studying these fatty acid ratios, one sample of one gram per animal is sufficient. However, due to the high individual variation between chicken for these ratios, a relatively high number of animals (minimum 15) are required to obtain a sufficiently high power to reveal significant effects of experimental factors (e.g. feeding regimes). The present experiment resulted in meat with a favorable concentration ratio between omega-6 and omega-3 fatty acids. The AA concentration varied from 1.5 to 2.8 g/100 g total fatty acids in thigh muscle in the fifteen broilers, and the ratio between AA and EPA concentrations ranged from 2.3 to 3.9. These differences among the birds may be due to genetic variance that can be exploited by breeding for lower AA

  19. Acetyl eugenol, a component of oil of cloves (Syzygium aromaticum L.) inhibits aggregation and alters arachidonic acid metabolism in human blood platelets.

    PubMed

    Srivastava, K C; Malhotra, N

    1991-01-01

    In continuation of our studies with the oil of cloves--a common kitchen spice and a crude drug for home medicine--we have isolated yet another active component identified as acetyl eugenol (AE); the earlier reported active component being eugenol. The isolated material (IM) was found to be a potent platelet inhibitor; IM abolished arachidonate (AA)-induced aggregation at ca. 12 microM, a concentration needed to abolish the second phase of adrenaline-induced aggregation. Chemically synthesized acetyl eugenol showed similar effects on AA- and adrenaline-induced aggregation. A dose-dependent inhibition of collagen-induced aggregation was also observed. AE did not inhibit either calcium ionophore A23187- or thrombin-induced aggregation. Studies on aggregation and ATP release were done using whole blood (WB). AA-induced aggregation in WB was abolished at 3 micrograms/ml (14.6 microM) which persisted even after doubling the concentration of AA. ATP release was inhibited. Inhibition of aggregation appeared to be mediated by a combination of two effects: reduced formation of thromboxane and increased generation of 12-lipoxygenase product (12-HPETE). These effects were observed by exposing washed platelets to (14C)AA or by stimulating AA-labelled platelets with ionophore A23187. Acetyl eugenol inhibited (14C)TxB2 formation in AA-labelled platelets on stimulation with thrombin. AE showed no effect on the incorporation of AA into platelet phospholipids. PMID:2011614

  20. Brain phospholipid arachidonic acid half-lives are not altered following 15 weeks of N-3 polyunsaturated fatty acid adequate or deprived diet

    PubMed Central

    Green, Joshua T.; Liu, Zhen; Bazinet, Richard P.

    2010-01-01

    Previous studies have infused radiolabeled arachidonic acid (AA) into rat brains and followed AA esterification into phospholipids for up to 24 h; however, the half-life of AA in rat brain phospholipids is unknown. Eighteen day old rats were fed either an n-3 PUFA adequate or deprived diet for 15 weeks. Following the 15 weeks, 40 µCi of [3H] AA was injected intracerebroventricularly into the right lateral ventricle using stereotaxic surgery and returned to their dietary treatment. From 4–120 days after [3H] AA administration, brains were collected for chemical analyses. The half-life of AA in rat brain phospholipids was 44 ± 4 days for the n-3 PUFA adequate group and 46 ± 4 days for the n-3 PUFA deprived group, which closely approximates the predicted half-life previously reported, based on the rate of entry from the plasma unesterified pool, suggesting the plasma unesterified pool is a major contributor to brain uptake of AA. Furthermore, unlike a previous report in which the half-life of brain phospholipid docosahexaenoic acid (DHA) was increased in n-3 PUFA deprived rats, n-3 PUFA deprivation did not significantly alter the AA half-life, suggesting different mechanisms exist to maintain brain concentrations of AA and DHA. PMID:19661256

  1. Roles of arachidonic acid, lipoxygenases and phosphatases in calcium-dependent modulation of M-current in bullfrog sympathetic neurons.

    PubMed Central

    Yu, S P

    1995-01-01

    1. M-current (IM) is regulated by intracellular free Ca2+ ([Ca2+]i). Suppression and overrecovery of IM induced by muscarine and luteinizing-hormone releasing hormone (LHRH) are also regulated by [Ca2+]i. The role of the arachidonic acid (AA) pathway in the Ca(2+)-dependent modulation of IM was investigated using whole-cell voltage clamp and intracellular perfusion in dissociated bullfrog sympathetic B neurons. 2. Quinacrine (10-20 microM) and 4-bromophenacyl bromide (4-BPB; 4-10 microM), the inhibitors of phospholipase A2, blocked the enhancement of IM evoked by raising [Ca2+]i. 3. AA (6-120 microM) increased IM by about 50% of the control current in a Ca(2+)-dependent manner. 4. Enhancements of IM by Ca2+ and AA were blocked by the lipoxygenase (LO) inhibitors nordihydroguaiaretic acid (NDGA; 1-5 microM) and 5,8,11-eicosatrynoic acid (ETI; 10 microM). The cyclo-oxygenase inhibitor indomethacin (10 microM) had no effect. 5. Enhancement of IM by Ca2+ was abolished by the selective 12-LO inhibitors baicalein (1-2 microM) and 15(S)-hydroxy-5-cis-8-cis-11-cis-13-trans-eicosatetraenoic acid (15-HETE; 6.5 microM). A 12-LO product, 2(S)-hydroxy-5-cis-8-cis-10-trans-14-cis- eicosatetraenoic acid (12-HETE; 13-20 microM), increased IM without Ca2+ requirement. 6. Enhancement of IM by Ca2+ was not affected by the selective 5-LO inhibitors AA-861 (10 microM), 5,6-dehydroarachidonic acid (5,6-DAA, 10 microM) and L-651,896 (10 microM). The 5-LO metabolites leukotriene C4 (1.5-8 microM) and leukotriene B4 (1.5-5 microM) showed no obvious effect on IM. 7. NDGA alone inhibited IM with an IC50 of 0.73 microM at 120 nM Cai(2+). 8. NDGA did not affect suppression of IM by muscarine or LHRH; however, overrecovery of IM upon removing these agonists was totally eliminated by 1 microM NDGA. 9. Inhibitors of phosphatases, calyculin A (0.1 microM) and okadaic acid (1 microM), completely abolished overrecovery of IM. Calyculin A also blocked the Ca(2+)-induced IM enhancement. 10. It is

  2. Endothelial-dependent vasodilators preferentially increase subendocardial blood flow

    SciTech Connect

    Pelc, L.R.; Gross, G.J.; Warltier, D.C.

    1986-03-05

    Interference with arachidonic acid metabolism on the effect of acetylcholine (Ach) or arachidonic acid (AA) to preferentially increase subendocardial perfusion was investigated in anesthetized dogs. Hemodynamics, regional myocardial blood flow (MBF (ml/min/g):radioactive microspheres) and the left ventricular transmural distribution of flow (endo/epi) were measured. Intracoronary infusion of Ach (10 ..mu..g/min) and AA (585 ..mu..g/min) significantly (P < .05*) increased myocardial perfusion and selectively redistributed flow to the subendocardium (increased endo/epi) without changes in systemic hemodynamics. Inhibition of phospholipase A/sub 2/ by quinacrine (Q; 600 ..mu..g/min, ic) attenuated the increase in myocardial perfusion produced by Ach but not by AA and inhibited the redistribution of flow to the subendocardium. The present results suggest that endothelium-dependent vasodilators produce a preferential increase in subendocardial perfusion via a product of AA metabolism.

  3. Incorporation and distribution of dihomo-gamma-linolenic acid, arachidonic acid, and eicosapentaenoic acid in cultured human keratinocytes

    SciTech Connect

    Punnonen, K.; Puustinen, T.; Jansen, C.T.

    1986-02-01

    Human keratinocytes in culture were labelled with /sup 14/C-dihomo-gamma-linolenic acid, /sup 14/C-arachidonic acid or /sup 14/C-eicosapentaenoic acid. All three eicosanoid precursor fatty acids were effectively incorporated into the cells. In phospholipids most of the radioactivity was recovered, in neutral lipids a substantial amount, and as free unesterified fatty acids only a minor amount. Most of the radioactivity was found in phosphatidylethanolamine which was also the major phospholipid as measured by phosphorous assay. The incorporation of dihomo-gamma-linolenic acid and arachidonic acid into lipid subfractions was essentially similar. Eicosapentaenoic acid was, however, much less effectively incorporated into phosphatidylinositol + phosphatidylserine and, correspondingly, more effectively into triacylglycerols as compared to the two other precursor fatty acids. Once incorporated, the distribution of all three precursor fatty acids was relatively stable, and only minor amounts of fatty acids were released into the culture medium during short term culture (two days). Our study demonstrates that eicosanoid precursor fatty acids are avidly taken up by human keratinocytes and esterified into membrane lipids. The clinical implication of this finding is that dietary manipulations might be employed to cause changes in the fatty acid composition of keratinocytes.

  4. Effects of a garlic-derived principle (ajoene) on aggregation and arachidonic acid metabolism in human blood platelets.

    PubMed

    Srivastava, K C; Tyagi, O D

    1993-08-01

    When garlic cloves are chopped or crushed several dialkyl thiosulfinates are rapidly formed by the action of the enzyme alliin lyase or alliinase (EC 4.4.1.4) on S(+)-alkyl-L-cysteine sulfoxides. Allicin (diallyl thiosulfinate or allyl 2-propene thiosulfinate) is the dominant thiosulfinate released. A variety of sulfur containing compounds are formed from allicin and other thiosulfinates depending on the way in which garlic is handled. One such compound identified recently is ajoene which has been reported to possess antithrombotic properties. We present here data on the antiplatelet properties of ajoene together with its effects on the metabolism of arachidonic acid (AA) in intact platelets. Thus, ajoene was found to inhibit platelet aggregation induced by AA, adrenaline, collagen, adenosine diphosphate (ADP) and calcium ionophore A23187; the nature of the inhibition was irreversible. In washed platelets stimulated by labelled arachidonate, ajoene inhibited the formation of thromboxane A2; 12-lipoxygenase product(s) were reduced at higher ajoene concentrations. This garlic-derived substance inhibited the incorporation of labelled AA into platelet phospholipids at higher concentration. In labelled platelets, on stimulation with either calcium ionophore A23187 or collagen, reduced amounts of thromboxane and 12-HETE (12-hydroxyeicosatetraenoic acid) were produced in ajoene-treated platelets compared to control platelets. This substance had no effect on the deacylation of platelet phospholipids. The results suggest that at least one of the mechanisms by which ajoene shows antiplatelet effects could be related to altered metabolism of AA.

  5. Lipoxin A4 and lipoxin B4 stimulate the release but not the oxygenation of arachidonic acid in human neutrophils: dissociation between lipid remodeling and adhesion.

    PubMed

    Nigam, S; Fiore, S; Luscinskas, F W; Serhan, C N

    1990-06-01

    The profiles of actions of lipoxin A4 (LXA4) and lipoxin B4 (LXB4), two lipoxygenase-derived eicosanoids, were examined with human neutrophils. At nanomolar concentrations, LXA4 and LXB4 each stimulated the release of [1-14C]arachidonic acid from esterified sources in neutrophils. Lipoxin-induced release of [1-14C]arachidonic acid was both dose- and time-dependent and was comparable to that induced by the chemotactic peptide f-met-leu-phe. Time-course studies revealed that lipoxin A4 and lipoxin B4 each induced a biphasic release of [1-14C]arachidonic acid, which was evident within seconds (5-15 sec) in its initial phase and minutes (greater than 30 sec) in the second phase. In contrast, the all-trans isomers of LXA4 and LXB4 did not provoke [1-14C]AA release. Lipoxin-induced release of arachidonic acid was inhibited by prior treatment of the cells with pertussis toxin but not by its beta-oligomers, suggesting the involvement of guaninine nucleotide-binding regulatory proteins in this event. Dual radiolabeling of neutrophil phospholipid classes with [1-14C]arachidonic acid and [3H]palmitic acid showed that phosphatidylcholine was a major source of lipoxin-induced release of [1-14C]arachidonic acid. They also demonstrated that lipoxins rapidly stimulate both formation of phosphatidic acid as well as phospholipid remodeling. Although both LXA4 and LXB4 (10(-8)-10(-6) M) stimulated the release of [1-14C]arachidonic acid, neither compound evoked its oxygenation by either the 5- or 15-lipoxygenase pathways (including the formation of LTB4, 20-COOH-LTB4, 5-HETE, or 15-HETE). LXA4 and LXB4 (10(-7) M) each stimulated the elevation of cytosolic Ca2+ as monitored with Fura 2-loaded cells, albeit to a lesser extent than equimolar concentrations of FMLP. Neither lipoxin altered the binding of [3H]LTB4 to its receptor on neutrophils. In addition, they did not stimulate aggregation or induce adhesion of neutrophils to human endothelial cells. Results indicate that both LXA4 and

  6. Effect of pentoxifylline on arachidonic acid metabolism, neutral lipid synthesis and accumulation during induction of the lipocyte phenotype by retinol in murine hepatic stellate cell.

    PubMed

    Cardoso, Carla C A; Paviani, Ernani R; Cruz, Lavínia A; Guma, Fátima C R; Borojevic, Radovan; Guaragna, Regina M

    2003-12-01

    In liver fibrosis, the quiescent hepatic stellate cells (HSC) are activated to proliferate and express the activated myofibroblast phenotype, losing fat droplets and the stored vitamin A, and depositing more extracellular matrix. Therapeutic strategies for liver fibrosis are focused on HSC. Pentoxifylline (PTF), an analog of the methylxanthine, prevents the biochemical and histological changes associated with animal liver fibrosis. The aim of the present study was to investigate the phenotypic change of myofibroblasts into quiescent lipocytes by PTF and/or retinol, using a permanent cell line GRX that represents murine HSC. We studied the action of both drugs on the synthesis of neutral lipids, activity of phospholipase A2 (PLA2), release of arachidonic acid (AA) and prostaglandins synthesis. Accumulation and synthesis of neutral lipids was dependent upon association of retinol with PTF. PTF (0.5 mg/mL) alone did not induce lipid accumulation and synthesis, but in cells induced by physiologic concentration of retinol (1-2.5 microM), it increased the quantity of stored lipids. Retinol and PTF (5 microM and 0.1 mg/mL, respectively) had a synergistic effect on neutral lipid synthesis and accumulation. In higher PTF concentrations (0.5 and 0.7 mg/ml), the synthesis was stimulated but accumulation decreased. Membrane-associated PLA2 activity decreased after PTF treatment, which increased the AA release 8 fold, and significantly increased the production of PGE2, but not of PGF2. However, when in presence of retinol, we observed a slightly higher increase in PGE2 and PGF2a production. In conclusion, PTF treatment generated an excess of free AA. We propose that retinol counteracts the action of PTF on the AA release and PGs production, even though both drugs stimulated the lipocyte induction in the HSC. PMID:14674680

  7. Differences in responsiveness of intrapulmonary artery and vein to arachidonic acid: mechanism of arterial relaxation involves cyclic guanosine 3':5'-monophosphate and cyclic adenosine 3':5'-monophosphate

    SciTech Connect

    Ignarro, L.J.; Harbison, R.G.; Wood, K.S.; Wolin, M.S.; McNamara, D.B.; Hyman, A.L.; Kadowitz, P.J.

    1985-06-01

    The objective of this study was to examine the relationship between responses of bovine intrapulmonary artery and vein to arachidonic acid and cyclic nucleotide levels in order to better understand the mechanism of relaxation elicited by arachidonic acid and acetylcholine. Arachidonic acid relaxed phenylephrine-precontracted arterial rings and elevated both cyclic GMP and cyclic AMP levels in arteries with intact endothelium. In contrast, endothelium-damaged arterial rings contracted to arachidonic acid without demonstrating significant changes in cyclic nucleotide levels. Indomethacin partially inhibited endothelium-dependent relaxation and abolished cyclic AMP accumulation whereas methylene blue, a guanylate cyclase inhibitor, partially inhibited relaxation and abolished cyclic GMP accumulation in response to arachidonic acid. All vessel responses were blocked by a combination of the two inhibitors. Prostaglandin (PG) I2 relaxed arterial rings and elevated cyclic AMP levels whereas PGE2 and PGF2 alpha caused contraction, suggesting that the indomethacin-sensitive component of arachidonic acid-elicited relaxation is due to PGI2 formation and cyclic AMP accumulation. The methylene blue-sensitive component is attributed to an endothelium-dependent but cyclooxygenase-independent generation of a substance causing cyclic GMP accumulation. Intrapulmonary veins contracted to arachidonic acid with no changes in cyclic nucleotide levels and PGI2 was without effect. Homogenates of intrapulmonary artery and vein formed 6-keto-PGF1 alpha, PGF2 alpha and PGE2 from (/sup 14/C)arachidonic acid, which was inhibited by indomethacin. Thus, bovine intrapulmonary vein may not possess receptors for PGI2.

  8. Molecular cloning and functional characterization of arachidonate 5-lipoxygenase (Alox5), and its expression in response to the ratio of linolenic acid to linoleic acid in diets of large yellow croaker (Larmichthys crocea).

    PubMed

    Wang, Tianjiao; Zuo, Rantao; Mai, Kangsen; Xu, Wei; Ai, Qinghui

    2016-11-01

    This study was conducted to clone and functionally characterize a full-length cDNA encoding arachidonate 5-lipoxygenase (Alox5) from large yellow croaker (Larmichthys crocea) and investigate its gene expression in response to graded dietary ratio of linolenic acid (ALA) to linoleic acid (LNA) (0.03, 0.06, 0.45, 0.90 and 1.51). An isolated 2372bp cDNA clone of Alox5 contained an open reading frame spanning 2025bp encoding a protein with the ability to modify arachidonate acid (AA) to 5-hydroxyeicosatetraenoic (5-HETE). In the liver, the Alox5 mRNA expression levels significantly increased to the maximum when the dietary ALA/LNA increased from 0.03 to 0.06, and then significantly decreased with dietary ALA/LNA increased to 1.51 (P<0.05). In the kidney, the expression levels of Alox5 of fish fed diets with low dietary ALA/LNA (0.03-0.06) were significantly higher than those of fish fed diets with high dietary ALA/LNA (0.45-1.51) (P<0.05). The dual-luciferase reporter assays showed that the nuclear factor kappa B (NF-κB) could act on cognate cis-acting elements in the promoter of Alox5 and increased the transcription of Alox5. Results of the present study suggested that the expression of Alox5 is higher in croakers fed high concentrations of LNA compared to those fed high concentrations of ALA, which might be regulated by NF-κB and contribute to the inflammation process by catalyzing the dioxygenation of AA. PMID:27378407

  9. Molecular cloning and functional characterization of arachidonate 5-lipoxygenase (Alox5), and its expression in response to the ratio of linolenic acid to linoleic acid in diets of large yellow croaker (Larmichthys crocea).

    PubMed

    Wang, Tianjiao; Zuo, Rantao; Mai, Kangsen; Xu, Wei; Ai, Qinghui

    2016-11-01

    This study was conducted to clone and functionally characterize a full-length cDNA encoding arachidonate 5-lipoxygenase (Alox5) from large yellow croaker (Larmichthys crocea) and investigate its gene expression in response to graded dietary ratio of linolenic acid (ALA) to linoleic acid (LNA) (0.03, 0.06, 0.45, 0.90 and 1.51). An isolated 2372bp cDNA clone of Alox5 contained an open reading frame spanning 2025bp encoding a protein with the ability to modify arachidonate acid (AA) to 5-hydroxyeicosatetraenoic (5-HETE). In the liver, the Alox5 mRNA expression levels significantly increased to the maximum when the dietary ALA/LNA increased from 0.03 to 0.06, and then significantly decreased with dietary ALA/LNA increased to 1.51 (P<0.05). In the kidney, the expression levels of Alox5 of fish fed diets with low dietary ALA/LNA (0.03-0.06) were significantly higher than those of fish fed diets with high dietary ALA/LNA (0.45-1.51) (P<0.05). The dual-luciferase reporter assays showed that the nuclear factor kappa B (NF-κB) could act on cognate cis-acting elements in the promoter of Alox5 and increased the transcription of Alox5. Results of the present study suggested that the expression of Alox5 is higher in croakers fed high concentrations of LNA compared to those fed high concentrations of ALA, which might be regulated by NF-κB and contribute to the inflammation process by catalyzing the dioxygenation of AA.

  10. Decreased arachidonic acid content and metabolism in tissues of NZB/W F1 females fed a diet containing 0. 45% dehydroisoandrosterone (DHA)

    SciTech Connect

    Matsunaga, A.; Cottam, G.L.

    1987-05-01

    A diet containing 0.45% DHA fed to NZB/W mice, a model of systemic lupus erythematosus, delays the time of onset, improves survival and decreases the formation of antibodies to ds-DNA. Essential fatty acid-deficient diets or inclusion of eicosapentaenoic acid have similar beneficial effects and led them to investigate arachidonic acid metabolism in response to feeding DHA. The arachidonic acid content of plasma cholesteryl ester decreased from 37.4 +/- 2.2 to 28.2 +/- 1.3 mg%. In total liver phospholipid the value decreased from 18.1 +/- 0.52 to 13.7 +/- 1.3 mg%, in total kidney phospholipid the value decreased from 24.10 +/- 0.87 to 20.7 +/- 0.32 mg% and in resident peritoneal macrophages the value decreased from 15.4 +/- 4.6 to 3.6 +/- 1.4 mg%. The metabolism of exogenous (1-/sup 14/C)arachidonic acid by resident peritoneal macrophages in response to Zymosan stimulation for 2 hr was examined by extraction of metabolites and separation by HPLC. Cells isolated from DHA-fed animals produced less PGE2 than controls, yet similar amounts of 6-keto PGF1..cap alpha.. were produced. Arachidonic acid metabolites have significant effects on the immune system and may be a mechanism involved in the benefits obtained by inclusion of DHA in the diet.

  11. Effects of arachidonic acid on the concentration of hydroxyeicosatetraenoic acids in culture media of mesenchymal stromal cells differentiating into adipocytes or osteoblasts.

    PubMed

    Casado-Díaz, Antonio; Ferreiro-Vera, Carlos; Priego-Capote, Feliciano; Dorado, Gabriel; Luque-de-Castro, María Dolores; Quesada-Gómez, José Manuel

    2014-01-01

    Metabolites derived from the polyunsaturated fatty acids (PUFA) may modulate the mesenchymal stromal cell (MSC) differentiation. Such cells can differentiate into different cellular types, including adipocytes and osteoblasts. Aging favors the bone marrow MSC differentiation toward the former, causing a loss of bone density associated with pathologies like osteoporosis. The omega-6 arachidonic acid (AA) favors MSC adipogenesis to a greater extent than omega-3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). In this work, we study the joint action of both PUFA. Thus, not induced and induced to adipocyte or osteoblast MSC were treated with 20 μM of each PUFA (either AA, AA + DHA or AA + EPA). The expression of osteogenic and adipogenic molecular markers, the alox15b lipoxygenase gene expression and the 5-, 8-, 11-, 12- and 15-hydroxyeicosatetraenoic acids (HETE) derived from the AA metabolism in the culture media were determined. The results show that the adipogenesis induction of AA is not suppressed by the joint presence of EPA and DHA. In fact, both increased the adipogenic effect of AA on MSC differentiated into osteoblasts. The different HETE concentrations increased in cultures supplemented with AA, albeit such concentrations were lower in the cultures induced to differentiate, mainly at day 21 after the induction. Furthermore, the reduction in the HETE concentration was correlated with a higher expression of the alox15b gene. These results highlight the PUFA metabolism differences between uninduced and induced MSC to differentiate into adipocytes and osteoblasts, besides the relevant role of the lipoxygenase gene expression in adipogenesis induction.

  12. Detection in vivo of a Novel Endogenous Etheno DNA Adduct Derived from Arachidonic Acid and the Effects of Antioxidants on Its Formation

    PubMed Central

    Cruz, Idalia M.; Pondicherry, Sharanya R.; Fernandez, Aileen; Schultz, Casey L.; Yang, Peiying; Pan, Jishen; Desai, Dhimant; Krzeminski, Jacek; Amin, Shantu; Christov, Plamen P.; Hara, Yukihiko; Chung, Fung-Lung

    2014-01-01

    Previous studies showed that the 7-(1′,2′-dihydroxyheptyl) substituted etheno DNA adducts are products from reactions with epoxide of (E)-4-hydroxy-2-nonenal (HNE), an oxidation product of ω-6 polyunsaturated fatty acids (PUFAs). In this work, we report the detection of 7-(1′,2′-dihydroxyheptyl)-1,N6-ethenodeoxyadenosine (DHHedA) in rodent and human tissues by two independent methods: a 32P-postlabeling/HPLC method and an isotope dilution liquid chromatography electrospray ionization tandem mass spectrometry method (ID-LC-ESI-MS/MS), demonstrating for the first time that DHHedA is a background DNA lesion in vivo. We showed that DHHedA can be formed upon incubation of arachidonic acid (AA) with deoxyadenosine (dA), supporting the notion that ω-6 PUFAs are the endogenous source of DHHedA formation. Because cyclic adducts are derived from the oxidation of PUFAs, we subsequently examined the effects of antioxidants, α-lipoic acid, Polyphenon E and vitamin E, on the formation of DHHedA and γ-hydroxy-1,N2-propanodeoxyguanosine (γ-OHPdG), a widely studied acrolein-derived adduct arising from oxidized PUFAs, in the livers of Long Evans Cinnamon (LEC) rats. LEC rats are inflicted with elevated lipid peroxidation and prone to the development of hepatocellular carcinomas. The results showed that while the survival of LEC rats increased significantly by α-lipoic acid, none of the antioxidants inhibited the formation of DHHedA and only Polyphenon E decreased the formation of γ-OHPdG. In contrast, vitamin E caused a significant increase in the formation of both γ-OHPdG and DHHedA in the livers of LEC rats. PMID:24816294

  13. Adaptation of myocardial blood flow to increased metabolic demand is not dependent on endothelial vasodilators in the rat heart.

    PubMed Central

    Tiefenbacher, C. P.; Tillmanns, H.; Niroomand, F.; Zimmermann, R.; Kübler, W.

    1997-01-01

    OBJECTIVE: To investigate the role of endothelial vasodilating factors in adaptation of myocardial blood flow to increased metabolic demands. DESIGN: Alterations in the effects of endothelium dependent (acetylcholine) and independent (sodium nitroprusside) vasodilators and the beta 1 receptor agonist dobutamine were studied after inhibition of endothelium derived relaxing factor (EDRF) with L-NG-nitro-arginine methyl ester (L-NAME), prostanoid synthesis with indomethacin, and ATP sensitive potassium channels with glibenclamide. EXPERIMENTAL ANIMALS: Female Wistar rats, in situ perfused heart. MAIN OUTCOME MEASURES: Myocardial blood flow (H2 clearance); systolic fractional thickening (pulsed Doppler); mean arterial blood pressure. RESULTS: L-NAME reduced myocardial blood flow by 58 (12)% (mean (SD), P < 0.001) and systolic thickening fraction (FT) by 36 (9)% (P < 0.05). These effects were significantly reversed by administration of L-arginine but not D-arginine. Pretreatment with L-NAME inhibited the increase in myocardial blood flow caused by acetylcholine (control: +42 (9)%; L-NAME: -29 (7)%, P < 0.001) but did not affect the increase in myocardial blood flow caused by sodium nitroprusside (control: +44 (5)%; L-NAME: +34 (10)%, NS). Pretreatment with L-NAME did not change the effect of dobutamine on myocardial blood flow (+61 (3)%) and FT (+32 (8)%) compared with baseline values (P < 0.001). Neither pretreatment with indomethacin nor with glibenclamide reduced the dobutamine induced increase in myocardial blood flow. CONCLUSIONS: Inhibition of EDRF, prostanoid synthesis, and ATP sensitive potassium channels did not reduce the vasodilator reserve during increased metabolic demands induced by beta 1 adrenergic stimulation. Therefore, adaptation of myocardial blood flow to increased metabolic demands is independent of endothelial relaxing factors in the rat heart. PMID:9068398

  14. Contact sensitizers modulate the arachidonic acid metabolism of PMA-differentiated U-937 monocytic cells activated by LPS

    SciTech Connect

    Del Bufalo, Aurelia; Bernad, Jose; Dardenne, Christophe; Verda, Denis; Meunier, Jean Roch; Rousset, Francoise; Martinozzi-Teissier, Silvia; Pipy, Bernard

    2011-10-01

    For the effective induction of a hapten-specific T cell immune response toward contact sensitizers, in addition to covalent-modification of skin proteins, the redox and inflammatory statuses of activated dendritic cells are crucial. The aim of this study was to better understand how sensitizers modulate an inflammatory response through cytokines production and COX metabolism cascade. To address this purpose, we used the human monocytic-like U-937 cell line differentiated by phorbol myristate acetate (PMA) and investigated the effect of 6 contact sensitizers (DNCB, PPD, hydroquinone, propyl gallate, cinnamaldehyde and eugenol) and 3 non sensitizers (lactic acid, glycerol and tween 20) on the production of pro-inflammatory cytokines (IL-1{beta} and TNF-{alpha}) and on the arachidonic acid metabolic profile after bacterial lipopolysaccharide (LPS) stimulation. Our results showed that among the tested molecules, all sensitizers specifically prevent the production of PMA/LPS-induced COX-2 metabolites (PGE{sub 2,} TxB{sub 2} and PGD{sub 2}), eugenol and cinnamaldehyde inhibiting also the production of IL-1{beta} and TNF-{alpha}. We further demonstrated that there is no unique PGE{sub 2} inhibition mechanism: while the release of arachidonic acid (AA) from membrane phospholipids does not appear do be a target of modulation, COX-2 expression and/or COX-2 enzymatic activity are the major steps of prostaglandin synthesis that are inhibited by sensitizers. Altogether these results add a new insight into the multiple biochemical effects described for sensitizers. - Highlights: > We investigated how contact sensitizers modulate an inflammatory response. > We used macrophage-differentiated cell line, U-937 treated with PMA/LPS. > Sensitizers specifically inhibit the production of COX metabolites (PGE2, TxB2). > Several mechanisms of inhibition: COX-2 expression/enzymatic activity, isomerases. > New insight in the biochemical properties of sensitizers.

  15. Arachidonic Acid Metabolite 19(S)-HETE Induces Vasorelaxation and Platelet Inhibition by Activating Prostacyclin (IP) Receptor

    PubMed Central

    Chennupati, Ramesh; Nüsing, Rolf M.; Offermanns, Stefan

    2016-01-01

    19(S)-hydroxy-eicosatetraenoic acid (19(S)-HETE) belongs to a family of arachidonic acid metabolites produced by cytochrome P450 enzymes, which play critical roles in the regulation of cardiovascular, renal and pulmonary functions. Although it has been known for a long time that 19(S)-HETE has vascular effects, its mechanism of action has remained unclear. In this study we show that 19(S)-HETE induces cAMP accumulation in the human megakaryoblastic leukemia cell line MEG-01. This effect was concentration-dependent with an EC50 of 520 nM, insensitive to pharmacological inhibition of COX-1/2 and required the expression of the G-protein Gs. Systematic siRNA-mediated knock-down of each G-protein coupled receptor (GPCR) expressed in MEG-01 followed by functional analysis identified the prostacyclin receptor (IP) as the mediator of the effects of 19(S)-HETE, and the heterologously expressed IP receptor was also activated by 19(S)-HETE in a concentration-dependent manner with an EC50 of 567 nM. Pretreatment of isolated murine platelets with 19(S)-HETE blocked thrombin-induced platelets aggregation, an effect not seen in platelets from mice lacking the IP receptor. Furthermore, 19(S)-HETE was able to relax mouse mesenteric artery- and thoracic aorta-derived vessel segments. While pharmacological inhibition of COX-1/2 enzymes had no effect on the vasodilatory activity of 19(S)-HETE these effects were not observed in vessels from mice lacking the IP receptor. These results identify a novel mechanism of action for the CYP450-dependent arachidonic acid metabolite 19(S)-HETE and point to the existence of a broader spectrum of naturally occurring prostanoid receptor agonists. PMID:27662627

  16. Biosynthesis, biological effects, and receptors of hydroxyeicosatetraenoic acids (HETEs) and oxoeicosatetraenoic acids (oxo-ETEs) derived from arachidonic acid.

    PubMed

    Powell, William S; Rokach, Joshua

    2015-04-01

    Arachidonic acid can be oxygenated by a variety of different enzymes, including lipoxygenases, cyclooxygenases, and cytochrome P450s, and can be converted to a complex mixture of oxygenated products as a result of lipid peroxidation. The initial products in these reactions are hydroperoxyeicosatetraenoic acids (HpETEs) and hydroxyeicosatetraenoic acids (HETEs). Oxoeicosatetraenoic acids (oxo-ETEs) can be formed by the actions of various dehydrogenases on HETEs or by dehydration of HpETEs. Although a large number of different HETEs and oxo-ETEs have been identified, this review will focus principally on 5-oxo-ETE, 5S-HETE, 12S-HETE, and 15S-HETE. Other related arachidonic acid metabolites will also be discussed in less detail. 5-Oxo-ETE is synthesized by oxidation of the 5-lipoxygenase product 5S-HETE by the selective enzyme, 5-hydroxyeicosanoid dehydrogenase. It actions are mediated by the selective OXE receptor, which is highly expressed on eosinophils, suggesting that it may be important in eosinophilic diseases such as asthma. 5-Oxo-ETE also appears to stimulate tumor cell proliferation and may also be involved in cancer. Highly selective and potent OXE receptor antagonists have recently become available and could help to clarify its pathophysiological role. The 12-lipoxygenase product 12S-HETE acts by the GPR31 receptor and promotes tumor cell proliferation and metastasis and could therefore be a promising target in cancer therapy. It may also be involved as a proinflammatory mediator in diabetes. In contrast, 15S-HETE may have a protective effect in cancer. In addition to GPCRs, higher concentration of HETEs and oxo-ETEs can activate peroxisome proliferator-activated receptors (PPARs) and could potentially regulate a variety of processes by this mechanism. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance".

  17. Biochemical and pharmacological effects of dipyrone and its metabolites in model systems related to arachidonic acid cascade.

    PubMed

    Weithmann, K U; Alpermann, H G

    1985-01-01

    The metabolites of dipyrone (metamizol, Novalgin) were compared with appropriate standard drugs for their influences on the pathways of the arachidonic acid metabolism. The drugs in this study had no significant effects on the lipoxygenase pathway in human neutrophils in vitro. The dipyrone metabolites 4-methylaminoantipyrine (MAAP) and 4-aminoantipyrine (AAP) inhibited prostaglandin synthesis in the 10(-3) to 10(-4) mol/l range thus being comparable to acetylsalicylic acid (ASA), whereas the two additional metabolites 4-acetylaminoantipyrine (AAAP) and 4-formylaminoantipyrine (FAAP) were practically inactive. This result is in accordance with the effects of the metabolites on the formation of oedema in the arthritis rat model, and supports published data showing that MAAP and AAP are the metabolites responsible for the clinical effects of dipyrone. Further systems in our study depending at least partially on the prostaglandin pathway were the release of antiaggregatory activity from rat aortae in vitro and the aggregation of human platelets induced by arachidonic acid in vitro. MAAP exhibits antiaggregatory activity (IC50 5 x 10(-6) mol/l), whereas the inhibitory effect on the vascular antiaggregatory release is much weaker. Compared to normals platelet aggregability ex vivo is enhanced in arthritic rats, but could significantly be lowered again by treatment of the rats with MAAP. A further system studied was the release of 6-keto-PGF1 alpha from rat mucosa in vitro and ex vivo. In vitro there is inhibition to be found with MAAP as well as with ASA. Ex vivo, however, dipyrone or MAAP slightly stimulates mucosal 6-keto-PGF1 alpha rather than inhibiting it, whereas ASA exerts inhibition, as expected.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Role of cytosolic phospholipase A2 in arachidonic acid release of rat-liver macrophages: regulation by Ca2+ and phosphorylation.

    PubMed Central

    Ambs, P; Baccarini, M; Fitzke, E; Dieter, P

    1995-01-01

    In this study we have verified the existence of a cytosolic phospholipase A2 (cPLA2) in rat-liver macrophages. Stimulation of these cells with phorbol 12-myristate 13-acetate (PMA), zymosan and lipopolysaccharide (LPS), but not with the Ca(2+)-ionophore A23187, leads to phosphorylation of cPLA2 and activation of mitogen-activated protein (MAP) kinase, supporting the hypothesis that MAP kinase is involved in cPLA2 phosphorylation. We show furthermore, that the tyrosine kinase inhibitor genistein prevents the LPS- but not the PMA- or zymosan-induced phosphorylation of cPLA2 and activation of MAP kinase, indicating that tyrosine kinases participate in LPS- but not in PMA- and zymosan-induced cPLA2 phosphorylation and MAP kinase activation. Phosphorylation of cPLA2 does not strongly correlate with stimulation of the arachidonic acid (AA) cascade: (1) A23187, a potent stimulator of AA release, fails to induce cPLA2 phosphorylation; (2) withdrawal of extracellular Ca2+, which inhibits PMA-stimulated AA release (Dieter, Schulze-Specking and Decker (1988) Eur. J. Biochem. 177, 61-67), has no effect on PMA-induced phosphorylation of cPLA2; (3) LPS induces cPLA2 phosphorylation within minutes, whereas increased AA release upon treatment with LPS is detectable for the first time after 4 h; and (4) genistein, which prevents LPS-induced cPLA2 phosphorylation, does not inhibit AA release in response to LPS. From these data we suggest that a rise in intracellular Ca2+, but not phosphorylation of cPLA2, is essential for activation of the AA cascade in rat-liver macrophages. Images Figure 1 Figure 3 Figure 4 Figure 5 PMID:7575453

  19. Vitamin A and arachidonic acid altered the skeletal mineralization in Atlantic cod (Gadus morhua) larvae without any interactions on the transcriptional level.

    PubMed

    Lie, Kai Kristoffer; Kvalheim, Karen; Rasinger, Josef Daniel; Harboe, Torstein; Nordgreen, Andreas; Moren, Mari

    2016-01-01

    The main object of this study was to evaluate the impact of different levels of vitamin A (VA) and arachidonic acid (ARA) in relation to eicosapentaenoic acid (EPA) on mineralization and gene expression in Atlantic cod larvae (Gadus morhua). First-feeding larvae were fed enriched rotifers from start-feeding until 29 days post hatch (dph). Larvae in four tanks were fed one of the following diets: control (EPA/ARA ratio: 15.8, 0.9μg VA g(-1)), control+VA (EPA/ARA ratio: 15.8, 7.8μg VA g(-1)), High ARA (EPA/ARA ratio: 0.9, 1.5μg VA g(-1)) or High ARA+VA (EPA/ARA ratio: 0.9, 12.0μg VA g(-1)). Larvae fed High ARA+VA were shorter at 29dph compared to the other groups and had significantly less mineralized bones when comparing larvae of similar size, showing interaction effects between VA and ARA. Although transcriptomic analysis did not reveal any interaction effects, a higher number of genes were differentially expressed in the high ARA fed larvae compared to control+VA fed larvae. Furthermore, bglap1, bglap2 and col10a1 were all down-regulated in larvae fed High ARA-diets and to a greater extent than larvae fed VA supplemented diet, indicating an additive effect on mineralization. In conclusion, this study showed that the dietary increase in ARA and VA altered the skeletal metabolism during larval development, most likely through signaling pathways specific for each nutrient rather than an interaction. The present study also demonstrates that VA could affect the larval response to ARA, even within the accepted non-toxic/non-deficient range.

  20. Development of a Nuclear Transformation System for Oleaginous Green Alga Lobosphaera (Parietochloris) incisa and Genetic Complementation of a Mutant Strain, Deficient in Arachidonic Acid Biosynthesis

    PubMed Central

    Khozin-Goldberg, Inna; Leu, Stefan; Shapira, Michal; Kaye, Yuval; Tourasse, Nicolas; Vallon, Olivier; Boussiba, Sammy

    2014-01-01

    Microalgae are considered a promising source for various high value products, such as carotenoids, ω-3 and ω-6 polyunsaturated fatty acids (PUFA). The unicellular green alga Lobosphaera (Parietochloris) incisa is an outstanding candidate for the efficient phototrophic production of arachidonic acid (AA), an essential ω-6 PUFA for infant brain development and a widely used ingredient in the baby formula industry. Although phototrophic production of such algal products has not yet been established, estimated costs are considered to be 2–5 times higher than competing heterotrophic production costs. This alga accumulates unprecedented amounts of AA within triacylglycerols and the molecular pathway of AA biosynthesis in L. incisa has been previously elucidated. Thus, progress in transformation and metabolic engineering of this high value alga could be exploited for increasing the efficient production of AA at competitive prices. We describe here the first successful transformation of L. incisa using the ble gene as a selection marker, under the control of the endogenous RBCS promoter. Furthermore, we have succeeded in the functional complementation of the L. incisa mutant strain P127, containing a mutated, inactive version of the delta-5 (Δ5) fatty acid desaturase gene. A copy of the functional Δ5 desaturase gene, linked to the ble selection marker, was transformed into the P127 mutant. The resulting transformants selected for zeocine resistant, had AA biosynthesis partially restored, indicating the functional complementation of the mutant strain with the wild-type gene. The results of this study present a platform for the successful genetic engineering of L. incisa and its long-chain PUFA metabolism. PMID:25133787

  1. Increases in Levels of Epoxyeicosatrienoic and Dihydroxyeicosatrienoic Acids (EETs and DHETs) in Liver and Heart in Vivo by 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) and in Hepatic EET:DHET Ratios by Cotreatment with TCDD and the Soluble Epoxide Hydrolase Inhibitor AUDA

    PubMed Central

    Diani-Moore, Silvia; Ma, Yuliang; Gross, Steven S.

    2014-01-01

    The environmental toxin and carcinogen 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin) binds and activates the transcription factor aryl hydrocarbon receptor (AHR), inducing CYP1 family cytochrome P450 enzymes. CYP1A2 and its avian ortholog CYP1A5 are highly active arachidonic acid epoxygenases. Epoxygenases metabolize arachidonic acid to four regioisomeric epoxyeicosatrienoic acids (EETs) and selected monohydroxyeicosatetraenoic acids (HETEs). EETs can be further metabolized by epoxide hydrolases to dihydroxyeicosatrienoic acids (DHETs). As P450–arachidonic acid metabolites affect vasoregulation, responses to ischemia, inflammation, and metabolic disorders, identification of their production in vivo is needed to understand their contribution to biologic effects of TCDD and other AHR activators. Here we report use of an acetonitrile-based extraction procedure that markedly increased the yield of arachidonic acid products by lipidomic analysis over a standard solid-phase extraction protocol. We show that TCDD increased all four EETs (5,6-, 8,9-, 11,12-, and 14,15-), their corresponding DHETs, and 18- and 20-HETE in liver in vivo and increased 5,6-EET, the four DHETs, and 18-HETE in heart, in a chick embryo model. As the chick embryo heart lacks arachidonic acid–metabolizing activity, the latter findings suggest that arachidonic acid metabolites may travel from their site of production to a distal organ, i.e., heart. To determine if the TCDD–arachidonic acid–metabolite profile could be altered pharmacologically, chick embryos were treated with TCDD and the soluble epoxide hydrolase inhibitor 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA). Cotreatment with AUDA increased hepatic EET-to-DHET ratios, indicating that the in vivo profile of P450–arachidonic acid metabolites can be modified for potential therapeutic intervention. PMID:24311719

  2. An arachidonic acid-preferring acyl-CoA synthetase is a hormone-dependent and obligatory protein in the signal transduction pathway of steroidogenic hormones.

    PubMed

    Cornejo Maciel, Fabiana; Maloberti, Paula; Neuman, Isabel; Cano, Florencia; Castilla, Rocío; Castillo, Fernanda; Paz, Cristina; Podestá, Ernesto J

    2005-06-01

    We have described that, in adrenal and Leydig cells, the hormonal regulation of free arachidonic acid (AA) concentration is mediated by the concerted action of two enzymes: an acyl-CoA thioesterase (MTE-I or ARTISt) and an acyl-CoA synthetase (ACS4). In this study we analyzed the potential regulation of these proteins by hormonal action in steroidogenic cells. We demonstrated that ACS4 is rapidly induced by adrenocorticotropin (ACTH) and cAMP in Y1 adrenocortical cells. The hormone and its second messenger increased ACS4 protein levels in a time and concentration dependent way. Maximal concentration of ACTH (10 mIU/ml) produced a significant effect after 15 min of treatment and exerted the highest increase (3-fold) after 30 min. Moreover, (35)S-methionine incorporation showed that the increase in ACS4 protein levels is due to an increase in the de novo synthesis of the protein. On the contrary MTE-I protein levels in Y1 and MA-10 cells did not change after steroidogenic stimuli. In contrast with the effect observed on protein levels, stimulation of both cell lines did not change ACS4 RNA levels during the first hour of treatment, indicating that the effect of both stimuli is exerted at the level of ACS4 protein synthesis.StAR protein induction has a key role on the activation of steroidogenesis since this protein increases the rate of the limiting step of the whole process. In agreement with the fact that the inhibition of ACS4 activity by triacsin C blocks cAMP-stimulated progesterone production by MA-10 Leydig cells, here we demonstrated that ACS4 inhibition also reduces StAR protein levels. Moreover, exogenous AA was able to overcome the effect of triacsin C on both events, StAR induction and steroidogenesis. These results were confirmed by experiments using ACS4-targeted siRNA which result in a reduction in both ACS4 and StAR protein levels. The concomitant decrease in steroid production was overcome by the addition of AA to the knocked-out cells. In summary

  3. Altered secretion of selected arachidonic acid metabolites during subclinical endometritis relative to estrous cycle stage and grade of fibrosis in mares.

    PubMed

    Gajos, Katarzyna; Kozdrowski, Roland; Nowak, Marcin; Siemieniuch, Marta J

    2015-08-01

    Mares that fail to become pregnant after repeated breeding, without showing typical signs of clinical endometritis, should be suspected of subclinical endometritis (SE). Contact with infectious agents results in altered synthesis and secretion of inflammatory mediators, including cytokines and arachidonic acid metabolites, and disturbs endometrial functional balance. To address the hypothesis that SE affects the immune endocrine status of the equine endometrium, spontaneous secretion of prostaglandin E(2) (PGE(2)), prostaglandin F(2α) (PGF(2α)), 6-keto-PGF(1α )(a metabolite of prostacyclin I(2)), leukotriene B(4) (LTB(4)), and leukotriene C(4) (LTC(4)) was examined. In addition, secretion of these factors was examined relative to the grade of inflammation, fibrosis, and estrous cycle stage. Eighty-two warmblood mares, of known breeding history, were enrolled in this study. On the basis of histopathologic assessment, mares were classified as suffering from first-grade SE, second-grade SE, or being healthy. The grade of fibrosis and the infiltration of endometrial tissue with polymorphonuclear leukocytes were examined by routine hematoxylin-eosin staining. In mares suffering from SE, the secretion profiles of PGE(2), 6-keto-PGF(1α), LTB(4), and LTC(4) were changed compared to mares that did not suffer from endometritis. The secretion of PGE(2) and 6-keto-PGF1α was increased, whereas that of LTB(4) and LTC(4) was decreased. Secretion of 6-keto-PGF(1α) was increased in first- and second-grade SE (P < 0.01). The concentration of PGI(2) metabolite was increased only in inflamed endometrium, independently of the inflammation grade, but was not affected by fibrosis. Prostaglandin E(2) secretion was increased in second-grade SE (P < 0.05). The secretion of LTB(4) decreased in both first- and second-grade SE (P < 0.05), whereas secretion of LTC(4) was decreased only in second-grade SE (P < 0.05). Fibrosis did not change the secretion profile of PGE(2), PGF(2α), and 6

  4. Food sources of arachidonic acid (PFA 20:4), listed in descending order by percentages of their contribution to intake, based on data from the National Health and Nutrition Examination Survey 2005-2006

    Cancer.gov

    Food sources of arachidonic acid (PFA 20:4), listed in descending order by percentages of their contribution to intake, based on data from the National Health and Nutrition Examination Survey 2005-2006

  5. Modulatory effects of steroid hormones, oxytocin, arachidonic acid, forskolin and cyclic AMP on the expression of aquaporin 1 and aquaporin 5 in the porcine uterus during placentation.

    PubMed

    Skowronska, A; Mlotkowska, P; Okrasa, S; Nielsen, S; Skowronski, M T

    2016-04-01

    Aquaporins (AQPs) are proteins forming trans-membrane channels responsible for water transport. AQP1 and AQP5 are present in structures of the female reproductive system. In the uterus, these AQPs are involved in water movement between the intraluminal, interstitial and capillary compartments and their uterine expression is essential throughout the pregnancy, including its early stages. Thus, the study aimed to assess the influence of P4 (progesterone), E2 (estradiol), OT (oxytocin), AA (arachidonic acid), cAMP and FSK (forskolin) on the AQP1 and AQP5 mRNA and protein expression in the uterine tissue of gilts on Days 30 - 32 of gestation (the placentation period), following short (3 h) and long (24 h) incubations. Steroid hormones influenced the expression of AQP1 and AQP5; E2 up-regulated, but P4 down-regulated mRNAs of these AQPs, whereas the protein level of studied AQPs was increased by both steroids. OT treatment decreased AQP1 (after 24 h), but increased AQP5 (after 3 h) mRNA expression. Treatment with AA significantly reduced the AQP1 expression at the mRNA level, but stimulated at the protein level. The expression of AQP5 mRNA and protein was stimulated by AA. FSK markedly decreased AQP1 mRNA, but increased of AQP5 after 3-h incubation. In turn, cAMP stimulated and inhibited transcription of AQP5 after 3- and 24-h incubations, respectively. Immunohistochemical analysis confirmed the uterine localization of AQP1 in the apical and basal membranes of endothelial cells and AQP5 in the apical membranes of epithelial cells under control condition. Treatments with P4, E2, AA, cAMP or FSK have caused additional appearance of AQP5 labeling in the basolateral membranes of epithelial cells. These results suggest a participation of steroid hormones (P4 and E2), AA derivatives and cAMP in controlling the expression of AQP1 and AQP5 as well as the distribution of AQP5 in the uterine tissue of pregnant gilts during placentation (Days 30 - 32 of gestation). PMID:27226190

  6. Intravenous anesthetic propofol suppresses prostaglandin E2 and cysteinyl leukotriene production and reduces edema formation in arachidonic acid-induced ear inflammation.

    PubMed

    Inada, Takefumi; Hirota, Kiichi; Shingu, Koh

    2015-01-01

    Propofol is an intravenous drug widely used for anesthesia and sedation. Previously, propofol was shown to inhibit cyclo-oxygenase (COX) and 5-lipoxygenase (5-LOX) activities. Because these enzyme-inhibiting effects have only been demonstrated in vitro, this study sought to ascertain whether similar effects might also be observed in vivo. In the current studies, effects of propofol were tested in a murine model of arachidonic acid-induced ear inflammation. Specifically, propofol - as a pre-treatment -- was intraperitoneally and then topical application of arachidonic acid was performed. After 1 h, tissue biopsies were collected and tested for the presence of edema and for levels of inflammatory mediators. The results indicated that the administration of propofol significantly suppressed ear edema formation, tissue myeloperoxidase activity, and tissue production of both prostaglandin E2 and cysteinyl leukotrienes. From the data, it can be concluded that propofol could exert anti-COX and anti-5-LOX activities in an in vivo model and that these activities in turn could have, at least in part, suppressed arachidonic acid-induced edema formation in the ear.

  7. Aureispira marina gen. nov., sp. nov., a gliding, arachidonic acid-containing bacterium isolated from the southern coastline of Thailand.

    PubMed

    Hosoya, Shoichi; Arunpairojana, Vullapa; Suwannachart, Chatrudee; Kanjana-Opas, Akkharawit; Yokota, Akira

    2006-12-01

    Three strains of gliding bacteria, 24(T), 62 and 71, isolated from a marine sponge and algae from the southern coastline of Thailand, were studied using a polyphasic approach to clarify their taxonomic positions. A phylogenetic analysis based on 16S rRNA gene sequences showed that the three isolates formed a distinct lineage within the family 'Saprospiraceae' of the phylum Bacteroidetes and were related to members of the genus Saprospira. The G+C contents of the isolates were in the range 38-39 mol%. The major respiratory quinone was MK-7. The predominant cellular fatty acids were 20 : 4omega6c (arachidonic acid), 16 : 0 and iso-17 : 0. On the basis of morphological, physiological and chemotaxonomic characteristics, together with DNA-DNA hybridization data and 16S rRNA gene sequences, the isolates represent a novel species of a novel genus, for which the name Aureispira marina gen. nov., sp. nov. is proposed. The type strain of Aureispira marina is 24(T) (=IAM 15389(T)=TISTR 1719(T)).

  8. Arachidonate 12-lipoxygenase may serve as a potential marker and therapeutic target for prostate cancer stem cells

    PubMed Central

    YIN, BO; YANG, YANG; ZHAO, ZHIQIANG; ZENG, YU; MOONEY, STEVEN M.; LI, MING; XU, XUEWEN; SONG, YONGSHENG; WU, BIN; YANG, ZHIBO

    2014-01-01

    The presence of arachidonate 12-lipoxygenase (12-LOX) potentiates prostate cancer (PCa) progression and therefore may be a good therapeutic target and/or a potential diagnostic predictor for PCa. In this study, we examined the expression of 12-LOX in PCa stem cells (PCa SCs) to test if it can serve as a unique marker and therapeutic target for PCa SCs. To this end, we isolated the cancer stem cell-like side population (SP) cells from the human PCa cell line DU-145 by a flow cytometry-based SP technique. The isolated DU-145 SP cells comprised a small population of the DU-145 cells. The SP cells had an up-regulation of ATP-binding cassette sub-family G member 2 (ABCG2) which enables these cells to efflux vital dyes and chemotherapeutic drugs. Furthermore, we detected a strong up-regulation of 12-LOX in these DU-145 SP cells compared to the parental DU-145 cells by RT-PCR and Western blot approaches. We also detected 12-LOX overexpression in PCa SCs in human PCa tissue samples by paraffin-section based immunofluorescent 4-channel confocal microscopy. However, no 12-LOX was detected in normal prostate epithelial SCs in normal prostate tissue samples. These multiple lines of evidence support the possibility that 12-LOX may serve as a unique marker and therapeutic target for PCa SCs. PMID:21225230

  9. Phaselicystis flava gen. nov., sp. nov., an arachidonic acid-containing soil myxobacterium, and the description of Phaselicystidaceae fam. nov.

    PubMed

    Garcia, Ronald O; Reichenbach, Hans; Ring, Michael W; Müller, Rolf

    2009-06-01

    A bacterial strain designated SBKo001(T) was isolated from a forest soil sample from Mt Makiling in Laguna, Philippines. It shows the general characteristics associated with myxobacteria, such as swarming of Gram-negative, rod-shaped vegetative cells, fruiting body formation and bacteriolytic activity. The strain is mesophilic, strictly aerobic and chemoheterotrophic and also exhibits resistance to various antibiotics. Major fatty acids are iso-C(15 : 0), C(17 : 1) 2-OH and C(20 : 4) (arachidonic acid). The G+C content of the genomic DNA is 69.2 mol%. A reference strain, NOSO-1 (=DSM 53757), isolated from the Etosha Basin in Namibia, shares nearly the same characteristics with SBKo001(T). The identical 16S rRNA gene sequences of the two strains show 94 % identity to strains of the cellulose-degrading Byssovorax and Sorangium species. Phylogenetic analysis reveals a novel branch diverging from the Polyangiaceae, Sorangiineae, Myxococcales. Their uniqueness in morphological growth stages, unusual fatty acid profile, broad-spectrum antibiotic resistance and branch divergence from the Polyangiaceae imply that strains SBKo001(T) and NOSO-1 not only represent a novel genus and species, proposed here as Phaselicystis flava gen. nov., sp. nov., but also belong to a new family, Phaselicystidaceae fam. nov. The type strain of Phaselicystis flava is SBKo001(T) (=DSM 21295(T) =NCCB 100230(T)).

  10. Arachidonic acid and docosahexaenoic acid suppress osteoclast formation and activity in human CD14+ monocytes, in vitro.

    PubMed

    Kasonga, Abe E; Deepak, Vishwa; Kruger, Marlena C; Coetzee, Magdalena

    2015-01-01

    An unbalanced diet can have adverse effects on health. Long chain polyunsaturated fatty acids (LCPUFAs) have been the focus of research owing to their necessity of inclusion in a healthy diet. However, the effects of LCPUFAs on human osteoclast formation and function have not been explored before. A human CD14+ monocyte differentiation model was used to elucidate the effects of an ω-3 LCPUFA, docosahexaenoic acid (DHA), and an ω-6 LCPUFA, arachidonic acid (AA), on osteoclast formation and activity. CD14+ monocytes were isolated from peripheral blood of healthy donors and stimulated with macrophage colony stimulating factor and receptor activator of nuclear factor kappa-B ligand to generate osteoclasts. Data from this study revealed that both the LCPUFAs decreased osteoclast formation potential of CD14+ monocytes in a dose-dependent manner when treated at an early stage of differentiation. Moreover, when exposed at a late stage of osteoclast differentiation AA and DHA impaired the bone resorptive potential of mature osteoclasts without affecting osteoclast numbers. AA and DHA abrogated vitronectin receptor expression in differentiating as well as mature osteoclasts. In contrast, the degree of inhibition for calcitonin receptor expression varied between the LCPUFAs with only AA causing inhibition during osteoclast differentiation. Furthermore, AA and DHA down regulated the expression of key osteoclast-specific genes in differentiating as well as mature osteoclasts. This study demonstrates for the first time that LCPUFAs can modulate osteoclast formation and function in a human primary osteoclast cell line.

  11. Determination of Eicosapentaenoic, Docosahexaenoic, and Arachidonic Acids in Human Plasma by High-Performance Liquid Chromatography with Electrochemical Detection.

    PubMed

    Kotani, Akira; Watanabe, Mizuki; Yamamoto, Kazuhiro; Kusu, Fumiyo; Hakamata, Hideki

    2016-01-01

    A high-performance liquid chromatography with electrochemical detection (HPLC-ECD) system was developed for the simultaneous determination of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA) in human plasma. In the present HPLC-ECD system, EPA, DHA, and AA were separated using a reverse-phase C30 column and detected based on the voltammetric reduction of 3,5-di-tert-butyl-1,2-benzoquinone (DBBQ). Chromatographic peak areas were proportional to the concentration of EPA, DHA, and AA from 0.75 μM to 0.1 mM (r > 0.998). The concentrations of EPA, DHA, and AA in plasma from healthy human subjects after overnight fasting were determined, and the ratio of EPA to AA was obtained by the present HPLC-ECD method, which required 40 μL of human plasma and a simple procedure of sample preparation using diethyl ether extraction. Moreover, changes in EPA, DHA, and AA concentrations in a human subject were monitored before and after fish oil supplement administration by the present HPLC-ECD system. PMID:27682409

  12. Arachidonic acid is involved in the regulation of hCG induced steroidogenesis in rat Leydig cells

    SciTech Connect

    Didolkar, A.K.; Sundaram, K.

    1987-07-27

    Phospholipase C (PLC), an enzyme involved in the hydrolysis of membrane phospholipid- phosphatidylinositol-bisphosphate to insositol triphosphate and diacylglycerol, and Phorbol 12, myristate 13, acetate (PMA) could significantly stimulate testosterone (T) secretion from Leydig cells. Arachidonic acid (AA) stimulated T secretion by about 2 fold. The steroidogenic effect of PLC and AA was biphasic. At low concentrations both PLC and AA augmented hCG induced T secretion, while at higher concentrations they inhibited steroid production. AA also had a biphasic effect on hCG induced cyclic AMP secretion. 5,8,11,14 Eicosatetrayenoic acid, a general inhibitor of AA metabolism, and Nordihydroguaiaretic acid, an inhibitor of the lipoxygenase pathway of AA metabolism, inhibited hCG induced T secretion while indomethacin, an inhibitor of cyclo-oxygenase pathway, had no effect on hCG induced T secretion. The authors conclude from these data that AA plays a role in the regulation of hCG induced steroidogenic responses in rat Leydig cells and that the metabolite(s) of AA that are involved are not cyclo-oxygenase products. 28 references, 4 figures, 2 tables.

  13. A new 5-lipoxygenase selective inhibitor derived from Artocarpus communis strongly inhibits arachidonic acid-induced ear edema.

    PubMed

    Koshihara, Y; Fujimoto, Y; Inoue, H

    1988-06-01

    Natural compounds isolated from the Indonesian plant, Artocarpus communis, inhibit 5-lipoxygenase of cultured mastocytoma cells. One of five compounds, AC-5-1, strongly inhibits 5-lipoxygenase with a half-inhibition dose of 5 +/- 0.12 X 10(-8) M. However, prostaglandin synthesizing activity is not inhibited until 10(-5) M. AC-5-1 is a highly selective inhibitor for 5-lipoxygenase. The AC-5-1 at 10(-5) M inhibits 96% of leukotriene C4 synthesis of mouse peritoneal cells facilitated by calcium-ionophore. Arachidonic acid-induced ear edema of mice, an in vivo inflammatory model, involving leukotriene induction, is strongly inhibited by AC-5-1 in a dose-dependent manner. The inhibition is the strongest of any inhibitors of 5-lipoxygenase reported previously. Since the natural compound AC-5-1 can selectively inhibit 5-lipoxygenase and affect in vivo inflammation, it will be interesting to investigate the role of leukotrienes on inflammation and other physiological processes.

  14. Mechanism of angiotensin II-induced arachidonic acid metabolite release in aortic smooth muscle cells: involvement of phospholipase D.

    PubMed

    Shinoda, J; Kozawa, O; Suzuki, A; Watanabe-Tomita, Y; Oiso, Y; Uematsu, T

    1997-02-01

    In a previous study, we have shown that angiotensin II (Ang II) activates phosphatidylcholine-hydrolyzing phospholipase D due to Ang II-induced Ca2+ influx from extracellular space in subcultured rat aortic smooth muscle cells. In the present study, we have investigated the role of phospholipase D in Ang II-induced arachidonic acid (AA) metabolite release and prostacyclin synthesis in subcultured rat aortic smooth muscle cells. Ang II significantly stimulated AA metabolite release in a concentration-dependent manner in the range between 1 nmol/I and 0.1 mumol/I. D.L.-Propranolol hydrochloride (propranolol), an inhibitor of phosphatidic acid phosphohydrolase, significantly inhibited the Ang II-induced release of AA metabolites. The Ang II-induced AA metabolite release was reduced by chelating extracellular Ca2+ with EGTA. Genistein, an inhibitor of protein tyrosine kinases, significantly suppressed the Ang II-induced AA metabolite release. 1,6-Bis-(cyclohexyloximinocarbonylamino)-hexane (RHC-80267), a potent and selective inhibitor of diacylglycerol lipase, significantly inhibited the Ang II-induced AA metabolite release. Both propranolol and RHC-80267 inhibited the Ang II-induced synthesis of 6-keto-prostaglandin F1 alpha, a stable metabolite of prostacyclin. The synthesis was suppressed by genistein. These results strongly suggest that the AA metabolite release induced by Ang II is mediated, at least in part, through phosphatidylcholine hydrolysis by phospholipase D activation in aortic smooth muscle cells.

  15. Lipoxygenase- and cyclooxygenase-reaction products and incorporation into glycerolipids or radiolabeled arachidonic acid in the bovine retina

    SciTech Connect

    Birkle, D.L.; Bazan, N.G.

    1984-02-01

    The metabolism of radiolabeled arachidonic acid (AA) by the intact bovine retina in vitro has been studied. Synthesis of prostaglandins (PGs) and hydroxyeicosatetraenoic acids (HETEs), and incorporation of AA into glycerolipids has been measured by reverse-phase and straight-phase high performance liquid chromatography with flow scintillation detection, and by thin-layer chromatography. AA was actively acylated into glycerolipids, particularly triglycerides, phosphatidylcholine and phosphatidylinositol. AA was also converted to the major PGs, PGF2 alpha, PGE2, PGD2, 6-keto-PGF1 alpha and TXB2, and to the lipoxygenase reaction products, 12-HETE, 5-HETE, and other monohydroxy isomers. Approximately 6% of the radiolabeled AA was converted to eicosanoids. The synthesis of HETEs was inhibited in a concentration-dependent manner (IC50 . 8.3 nM) by nordihydroguaiaretic acid (NDGA). PG synthesis was inhibited by aspirin (10 microM), indomethacin (1 microM) and NDGA (IC50 . 380 nM). Metabolism of AA via lipoxygenase, cyclooxygenase and activation-acylation was inhibited by boiling retinal tissue prior to incubation. These studies demonstrate an active system for the uptake and utilization of AA in the bovine retina, and provide the first evidence of lipoxygenase-mediated metabolism of AA, resulting in the synthesis of mono-hydroxyeicosatetraenoic acids, in the retina.

  16. Bacterial lipopolysaccharide primes human neutrophils for enhanced release of arachidonic acid and causes phosphorylation of an 85-kD cytosolic phospholipase A2.

    PubMed Central

    Doerfler, M E; Weiss, J; Clark, J D; Elsbach, P

    1994-01-01

    Production of leukotriene B4 (LTB4) by human neutrophils (PMN) in response to different stimuli is increased after pretreatment with lipopolysaccharides (LPS). We have analyzed the steps in arachidonic acid (AA) metabolism affected by LPS by examining release of AA and its metabolites from [3H]AA prelabeled PMN. Pretreatment of PMN for 60 min with up to 1 microgram/ml of LPS alone had no effect, but release of [3H]AA was stimulated up to fivefold during subsequent stimulation with a second agent. In the absence of LPS-binding protein (LBP), priming was maximal after pretreatment of PMN with 10 ng of LPS/ml for 60 min; in the presence of LBP maximal priming occurred within 45 min at 0.1 ng of LPS/ml and within 15 min at 100 ng of LPS/ml. Treatment of PMN with 10 ng of LPS/ml also increased uptake of opsonized zymosan by up to 60%. Phospholipids are the source of released [3H]AA. No release was observed from [14C]oleic acid (OA)-labeled PMN suggesting that phospholipolysis may be specific for [3H]AA-labeled phospholipid pools. Cytosol from PMN primed with LPS contains two to three times the phospholipase A2 (PLA2) activity of control PMN, against 1-palmitoyl-[2-14C]arachidonoyl-phosphatidylcholine. This activity is Ca2+ dependent and dithiothreitol resistant. LPS priming is accompanied by reduced migration during SDS-PAGE of an 85-kD protein, identified as a cytosolic PLA2. The extent and kinetics of this effect of LPS on cPLA2 parallel the priming of [3H]AA release, both depending on LPS concentration either with or without LBP. These findings suggest that priming by LPS of AA metabolism by PMN includes phosphorylation of an AA-phospholipid-selective cytosolic PLA2 that is dissociated from activation until a second stimulus is applied. Images PMID:7512985

  17. Arachidonic acid release from rat Leydig cells: the involvement of G protein, phospholipase A2 and regulation of cAMP production.

    PubMed

    Ronco, A M; Moraga, P F; Llanos, M N

    2002-01-01

    We have previously demonstrated that the release of arachidonic acid (AA) from human chorionic gonadotropin (hCG)-stimulated Leydig cells occurs in a dose- and time-dependent manner. In addition, the amount of AA released was dependent on the hormone-receptor interaction and the concentration of LH-hCG binding sites on the cell surface. The present study was conducted to evaluate the involvement of phospholipase A(2) (PLA(2)) and G proteins in AA release from hormonally stimulated rat Leydig cells, and the possible role of this fatty acid in cAMP production. Cells were first prelabelled with [(14)C]AA to incorporate the fatty acid into cell phospholipids, and then treated in different ways to evaluate AA release. hCG (25 mIU) increased the release of AA to 180+/-12% when compared with AA released from control cells, arbitrarily set as 100%. Mepacrine and parabromophenacyl bromide (pBpB), two PLA(2) inhibitors, decreased the hormone-stimulated AA release to 85+/-9 and 70+/-24% respectively. Conversely, melittin, a PLA(2) stimulator, increased the release of AA up to 200% over control. The inhibitory effect of mepacrine on the release of AA was evident in hCG-treated Leydig cells, but not in the melittin-treated cells. To determine if the release of AA was also mediated through a G protein, cells were first permeabilized and subsequently treated with pertussis toxin or GTPgammaS, a non-hydrolyzable analog of GTP. Results demonstrate that GTPgammaS was able to induce a similar level of the release of AA as hCG. In addition, pertussis toxin completely abolished the stimulatory effect of hCG on the release of AA, indicating that a member of the G(i) family was involved in the hCG-dependent release of AA. Cells treated with PLA(2) inhibitors did not modify cAMP production, but exogenously added AA significantly reduced cAMP production from hCG-treated Leydig cells, in a manner dependent on the concentration of AA and hCG. Results presented here suggest an involvement of

  18. Interactions between protein kinase C and arachidonic acid in the gonadotropin response to salmon and chicken gonadotropin-releasing hormone-II in goldfish.

    PubMed

    Chang, J P; Van Goor, F; Neumann, C M

    1994-03-01

    Previous studies have shown that, in goldfish, the gonadotropin (GTH) response to salmon GTH-releasing hormone (sGnRH) is partly mediated by arachidonic acid (AA) metabolism via the lipoxygenase enzyme system, whereas protein kinase C (PKC) participates in both sGnRH- and chicken (c)GnRH-II-induced GTH secretion. In this study, the interactions between AA- and PKC-dependent pathways in mediating the long-term GnRH stimulation of GTH release were further investigated using dispersed goldfish pituitary cell cultures in static incubation. Treatments with AA or the PKC activator tetradecanoylphorbol acetate (TPA) increased GTH release. The GTH responses to AA and TPA were additive. The lipoxygenase inhibitor nordihydroguairetic acid (NDGA) and the PKC inhibitor H7 selectively reduced AA- and TPA-stimulated GTH release, respectively. These findings suggest that the GTH responses to stimulation by AA- and PKC-dependent signaling pathways are independent of one another. In other experiments, the GTH response to cGnRH-II was unaffected by NDGA but was abolished by H7. In contrast, sGnRH-induced GTH release was attenuated by NDGA and H7. Furthermore, in the presence of both NDGA and H7, the GTH response to sGnRH was abolished. These data suggest that sGnRH stimulation of GTH secretion involves both AA- and PKC-dependent mechanisms; in contrast, cGnRH-II action is not dependent on AA metabolism. The pathway by which AA might be mobilized in response to a GnRH challenge was also investigated by pharmacological manipulations. The diacylglcerol (DG) lipase inhibitor, U-57908, did not decrease sGnRH- and cGnRH-II-induced GTH secretion. On the other hand, the phospholipase A2 (PLA2) inhibitors, bromophenacyl bromide (BPB), chloroquine, and quinacrine, reduced sGnRH-elicited, but not cGnRH-II-stimulated GTH release. The addition of AA reversed the inhibitory action of BPB on sGnRH-elicited GTH release. In addition, the GTH response to AA was additive to the cGnRH-II-induced, but

  19. Differences in Arachidonic Acid Levels and Fatty Acid Desaturase (FADS) Gene Variants in African Americans and European Americans with Diabetes/Metabolic Syndrome

    PubMed Central

    Sergeant, Susan; Hugenschmidt, Christina E.; Rudock, Megan E.; Ziegler, Julie T.; Ivester, Priscilla; Ainsworth, Hannah C.; Vaidya, Dhananjay; Case, L. Douglas; Langefeld, Carl D.; Freedman, Barry I.; Bowden, Donald W.; Mathias, Rasika A.; Chilton, Floyd H.

    2012-01-01

    Over the past 50 years, increases in dietary n-6 polyunsaturated fatty acids (PUFAs), such as linoleic acid, have been hypothesized to cause or exacerbate chronic inflammatory diseases. This study examines an individual’s innate capacity to synthesize n-6-long chain PUFAs (LC-PUFAs), with respect to the fatty acid desaturase (FADS) locus in Americans of African and European descent with diabetes/metabolic syndrome. Compared to European Americans (EAm), African Americans (AfAm) exhibited markedly higher serum levels of arachidonic acid (AA) (EAm 7.9±2.1; AfAm 9.8±1.9 % of total fatty acids, mean ± sd; p<2.29×10−9) and the AA to n-6-precursor fatty acid ratio, which estimates FADS1 activity (EAm 5.4±2.2, AfAm 6.9±2.2; p=1.44×10−5). Seven single nucleotide polymorphisms (SNP) mapping to the FADS locus revealed strong association with AA, eicosapentaenoic acid (EPA) and dihomogamma-linolenic acid (DGLA) in the EAm. Importantly, EAm homozygous for the minor allele (T) had significantly lower AA levels (TT: 6.3±1.0; GG: 8.5±2.1; p=3.0×10−5) and AA/DGLA ratios (TT: 3.4±0.8; GG: 6.5±2.3; p=2.2×10−7) but higher DGLA levels (TT: 1.9±0.4; GG: 1.4±0.4; p=3.3×10−7) compared to those homozygous for the major allele (GG). Allele frequency patterns suggest that the GG genotype at rs174537 (associated with higher circulating levels of AA) is much higher in AfAm (0.81) compared to EAm (0.46). Similarly, marked differences in rs174537 genotypic frequencies were observed in HapMap populations. These data suggest that there are likely important differences in the capacity of different populations to synthesize LC-PUFAs. These differences may provide a genetic mechanism contributing to health disparities between populations of African and European descent. PMID:21733300

  20. Insulin decreases atherosclerotic plaque burden and increases plaque stability via nitric oxide synthase in apolipoprotein E-null mice.

    PubMed

    Mori, Yusaku; Chiang, Simon; Bendeck, Michelle P; Giacca, Adria

    2016-08-01

    It has been argued whether insulin accelerates or prevents atherosclerosis. Although results from in vitro studies have been conflicting, recent in vivo mice studies demonstrated antiatherogenic effects of insulin. Insulin is a known activator of endothelial nitric oxide synthase (NOS), leading to increased production of NO, which has potent antiatherogenic effects. We aimed to examine the role of NOS in the protective effects of insulin against atherosclerosis. Male apolipoprotein E-null mice (8 wk old) fed a high-cholesterol diet (1.25% cholesterol) were assigned to the following 12-wk treatments: control, insulin (0.05 U/day via subcutaneous pellet), N(ω)-nitro-l-arginine methyl ester hydrochloride (l-NAME, via drinking water at 100 mg/l), and insulin plus l-NAME. Insulin reduced atherosclerotic plaque burden in the descending aorta by 42% compared with control (plaque area/aorta lumen area: control, 16.5 ± 1.9%; insulin, 9.6 ± 1.3%, P < 0.05). Although insulin did not decrease plaque burden in the aortic sinus, macrophage accumulation in the plaque was decreased by insulin. Furthermore, insulin increased smooth muscle actin and collagen content and decreased plaque necrosis, consistent with increased plaque stability. In addition, insulin treatment increased plasma NO levels, decreased inducible NOS staining, and tended to increase phosphorylated vasodilator-stimulated phosphoprotein staining in the plaques of the aortic sinus. All these effects of insulin were abolished by coadministration of l-NAME, whereas l-NAME alone showed no effect. Insulin also tended to increase phosphorylated endothelial NOS and total neuronal NOS staining, effects not modified by l-NAME. In conclusion, we demonstrate that insulin treatment decreases atherosclerotic plaque burden and increases plaque stability through NOS-dependent mechanisms. PMID:27221119

  1. Positive Selection on a Regulatory Insertion–Deletion Polymorphism in FADS2 Influences Apparent Endogenous Synthesis of Arachidonic Acid

    PubMed Central

    Kothapalli, Kumar S. D.; Ye, , Kaixiong; Gadgil, Maithili S.; Carlson, Susan E.; O’Brien, Kimberly O.; Zhang, Ji Yao; Park, Hui Gyu; Ojukwu, Kinsley; Zou, James; Hyon, Stephanie S.; Joshi, Kalpana S.; Gu, Zhenglong; Keinan, Alon; Brenna, J.Thomas

    2016-01-01

    Long chain polyunsaturated fatty acids (LCPUFA) are bioactive components of membrane phospholipids and serve as substrates for signaling molecules. LCPUFA can be obtained directly from animal foods or synthesized endogenously from 18 carbon precursors via the FADS2 coded enzyme. Vegans rely almost exclusively on endogenous synthesis to generate LCPUFA and we hypothesized that an adaptive genetic polymorphism would confer advantage. The rs66698963 polymorphism, a 22-bp insertion–deletion within FADS2, is associated with basal FADS1 expression, and coordinated induction of FADS1 and FADS2 in vitro. Here, we determined rs66698963 genotype frequencies from 234 individuals of a primarily vegetarian Indian population and 311 individuals from the US. A much higher I/I genotype frequency was found in Indians (68%) than in the US (18%). Analysis using 1000 Genomes Project data confirmed our observation, revealing a global I/I genotype of 70% in South Asians, 53% in Africans, 29% in East Asians, and 17% in Europeans. Tests based on population divergence, site frequency spectrum, and long-range haplotype consistently point to positive selection encompassing rs66698963 in South Asian, African, and some East Asian populations. Basal plasma phospholipid arachidonic acid (ARA) status was 8% greater in I/I compared with D/D individuals. The biochemical pathway product–precursor difference, ARA minus linoleic acid, was 31% and 13% greater for I/I and I/D compared with D/D, respectively. This study is consistent with previous in vitro data suggesting that the insertion allele enhances n-6 LCPUFA synthesis and may confer an adaptive advantage in South Asians because of the traditional plant-based diet practice. PMID:27188529

  2. COX-2, aspirin and metabolism of arachidonic, eicosapentaenoic and docosahexaenoic acids and their physiological and clinical significance.

    PubMed

    Poorani, R; Bhatt, Anant N; Dwarakanath, B S; Das, Undurti N

    2016-08-15

    Polyunsaturated fatty acids (PUFAs) are vital for normal growth and development and physiological function of various tissues in humans. PUFAs have immunomodulatory actions in addition to their ability to modulate inflammation, vascular reactivity, neurotransmission and stem cell biology. PUFAs and their metabolites possess both pro- and anti-inflammatory properties that underlie their actions and involvement in several diseases. Aspirin, a non-steroidal anti-inflammatory drug (NSAID), possesses both cyclo-oxygenase (COX) and lipoxygenase (LOX) inhibitory action and enhances the production of anti-inflammatory lipoxin A4 {(called as epi-lipoxin A4, aspirin-triggered lipoxins (ATLs))}. In addition, at low doses aspirin may not interfere with the production of prostacyclin (PGI2). Both lipoxin A4 and PGI2 have vasodilator, platelet anti-aggregator and anti-inflammatory actions that may underlie the beneficial actions of aspirin. Paradoxically, other NSAIDs may not have the same actions as that of aspirin on PUFA metabolism. Similar anti-inflammatory compounds are formed from eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) by the action of aspirin termed as resolvins (from EPA and DHA) and protectins and maresins from DHA. PUFAs: arachidonic acid (AA), EPA and DHA and their various products modulate not only inflammation and immune response but also possess actions on various genes, nuclear factors, cyclic AMP and GMP, G-protein coupled receptors (GPRs), hypothalamic neurotransmitters, hormones, cytokines and enzymes, and interact with nitric oxide, carbon monoxide, and hydrogen sulfide to regulate their formation and action and to form new compounds that have several biological actions. These pleiotropic actions of PUFAs and their metabolites may explain their ability to play a role in several physiological actions and diseases. The big challenge is to harness these actions to prevent and manage clinical conditions. PMID:26335394

  3. Positive Selection on a Regulatory Insertion-Deletion Polymorphism in FADS2 Influences Apparent Endogenous Synthesis of Arachidonic Acid.

    PubMed

    Kothapalli, Kumar S D; Ye, Kaixiong; Gadgil, Maithili S; Carlson, Susan E; O'Brien, Kimberly O; Zhang, Ji Yao; Park, Hui Gyu; Ojukwu, Kinsley; Zou, James; Hyon, Stephanie S; Joshi, Kalpana S; Gu, Zhenglong; Keinan, Alon; Brenna, J Thomas

    2016-07-01

    Long chain polyunsaturated fatty acids (LCPUFA) are bioactive components of membrane phospholipids and serve as substrates for signaling molecules. LCPUFA can be obtained directly from animal foods or synthesized endogenously from 18 carbon precursors via the FADS2 coded enzyme. Vegans rely almost exclusively on endogenous synthesis to generate LCPUFA and we hypothesized that an adaptive genetic polymorphism would confer advantage. The rs66698963 polymorphism, a 22-bp insertion-deletion within FADS2, is associated with basal FADS1 expression, and coordinated induction of FADS1 and FADS2 in vitro. Here, we determined rs66698963 genotype frequencies from 234 individuals of a primarily vegetarian Indian population and 311 individuals from the US. A much higher I/I genotype frequency was found in Indians (68%) than in the US (18%). Analysis using 1000 Genomes Project data confirmed our observation, revealing a global I/I genotype of 70% in South Asians, 53% in Africans, 29% in East Asians, and 17% in Europeans. Tests based on population divergence, site frequency spectrum, and long-range haplotype consistently point to positive selection encompassing rs66698963 in South Asian, African, and some East Asian populations. Basal plasma phospholipid arachidonic acid (ARA) status was 8% greater in I/I compared with D/D individuals. The biochemical pathway product-precursor difference, ARA minus linoleic acid, was 31% and 13% greater for I/I and I/D compared with D/D, respectively. This study is consistent with previous in vitro data suggesting that the insertion allele enhances n-6 LCPUFA synthesis and may confer an adaptive advantage in South Asians because of the traditional plant-based diet practice. PMID:27188529

  4. ATP-mediated release of arachidonic acid metabolites from venular endothelium causes arteriolar dilation.

    PubMed

    Hammer, L W; Ligon, A L; Hester, R L

    2001-06-01

    This study was designed to test the hypothesis that venular administration of ATP resulted in endothelium-dependent dilation of adjacent arterioles through a mechanism involving cyclooxygenase products. Forty-three male golden hamsters were anesthetized with pentobarbital sodium (60 mg/kg ip), and the cremaster muscle was prepared for in vivo microscopy. ATP (100 microM) injected into venules dilated adjacent arterioles from a mean diameter of 51 +/- 4 to 76 +/- 6 microm (P < 0.05, n = 6). To remove the source of endothelial-derived relaxing factors, the venules were then perfused with air bubbles to disrupt the endothelium. Resting arteriolar diameter was not altered after disruption of the venular endothelium (51 +/- 5 microm), and the responses to venular ATP infusions were significantly attenuated (59 +/- 4 microm, P < 0.05). To determine whether the relaxing factor was a cyclooxygenase product, ATP infusion studies were repeated in the absence and presence of indomethacin (28 microM). Under control conditions, ATP (100 microM) infusion into the venule caused an increase in mean arteriolar diameter from 55 +/- 4 to 78 +/- 3 microm (P < 0.05, n = 6). In the presence of indomethacin, mean resting arteriolar tone was not significantly altered (49 +/- 4 microm), and the response to ATP was significantly attenuated (54 +/- 4 microm, P < 0.05, n = 6). These studies show that increases in venular ATP concentrations stimulate the release of cyclooxygenase products, possibly from the venular endothelium, to vasodilate the adjacent arteriole. PMID:11356617

  5. Toxicological evaluation of arachidonic acid (ARA)-rich oil and docosahexaenoic acid (DHA)-rich oil.

    PubMed

    Lewis, Kara D; Huang, Weifeng; Zheng, Xiaohui; Jiang, Yue; Feldman, Robin S; Falk, Michael C

    2016-10-01

    The safety of DHA-rich oil from Schizochytrium sp. and ARA-rich oil from Mortierella alpina was separately evaluated by testing for gene mutations, clastogenicity, and aneugenicity, and by conducting 28-day and 90-day dietary studies in Wistar rats. The results of all genotoxicity tests were negative. The 28-day and 90-day studies involved dietary exposure to 1000, 2500, and 5000 mg per kg bw of the DHA-rich and ARA-rich oils and two control diets: water and corn oil (vehicle control). There were no treatment-related effects of either the DHA-rich or ARA-rich oils on clinical observations, body weight, food consumption, behavior, hematology, clinical chemistry, coagulation, urinalysis parameters, or necropsy findings. Increases in cholesterol and triglyceride levels were considered related to a high oil diet and non-adverse. The no observable adverse effect level (NOAEL) for both the DHA-rich and ARA-rich oils was 5000 mg per kg bw, the highest dose tested. The results confirm that these oils possess toxicity profiles similar to those of other currently marketed oils and support the safety of DHA-rich oil from Schizochytrium sp. and ARA-rich oil from Mortierella alpina for their proposed uses in food. PMID:27470615

  6. Arachidonic acid-induced expression of the organic solute and steroid transporter-beta (Ost-beta) in a cartilaginous fish cell line.

    PubMed

    Hwang, Jae-Ho; Parton, Angela; Czechanski, Anne; Ballatori, Nazzareno; Barnes, David

    2008-07-01

    The organic solute and steroid transporter (OST/Ost) is a unique membrane transport protein heterodimer composed of subunits designated alpha and beta, that transports conjugated steroids and prostaglandin E(2) across the plasma membrane. Ost was first identified in the liver of the cartilaginous fish Leucoraja erinacea, the little skate, and subsequently was found in many other species, including humans and rodents. The present study describes the isolation of a new cell line, LEE-1, derived from an early embryo of L. erinacea, and characterizes the expression of Ost in these cells. The mRNA size and amino acid sequence of Ost-beta in LEE-1 were identical to that previously reported for Ost-beta from skate liver, and the primary structure was identical to that of the spiny dogfish shark (Squalus acanthias) with the exception of a single amino acid. Ost-beta was found both on the plasma membrane and intracellularly in LEE-1 cells, consistent with its localization in other cell types. Interestingly, arachidonic acid, the precursor to eicosanoids, strongly induced Ost-beta expression in LEE-1 cells and a lipid mixture containing arachidonic acid also induced Ost-alpha. Overall, the present study describes the isolation of a novel marine cell line, and shows that this cell line expresses relatively high levels of Ost when cultured in the presence of arachidonic acid. Although the function of this transport protein in embryo-derived cells is unknown, it may play a role in the disposition of eicosanoids or steroid-derived molecules.

  7. Expression of Phospholipases A2 in Primary Human Lung Macrophages. Role of Cytosolic Phospholipase A2–α in Arachidonic Acid Release and Platelet Activating Factor Synthesis

    PubMed Central

    Giannattasio, Giorgio; Lai, Ying; Granata, Francescopaolo; Mounier, Carine M.; Nallan, Laxman; Oslund, Rob; Leslie, Christina C.; Marone, Gianni; Lambeau, Gérard; Gelb, Michael H.; Triggiani, Massimo

    2009-01-01

    Summary Macrophages are a major source of lipid mediators in the human lung. Expression and contribution of cytosolic (cPLA2) and secreted phospholipases A2 (sPLA2) to the generation of lipid mediators in human macrophages is unclear. We investigated the expression and role of different PLA2s in the production of lipid mediators in primary human lung macrophages. Macrophages express the alpha, but not the zeta isoform of group IV and group VIA cPLA2 (iPLA2). Two structurally-divergent inhibitors of group IV cPLA2 completely block arachidonic acid release by macrophages in response to non-physiological (Ca2+ ionophores and phorbol esters) and physiological agonists (lipopolysaccharide and Mycobacterium protein derivative). These inhibitors also reduce by 70% the synthesis of platelet-activating factor by activated macrophages. Among the full set of human sPLA2s, macrophages express group IIA, IID, IIE, IIF, V, X and XIIA, but not group IB and III enzymes. Me-Indoxam, a potent and cell impermeable inhibitor of several sPLA2s, has no effect on arachidonate release or platelet-activating factor production. Agonist-induced exocytosis is not influenced by cPLA2 inhibitors at concentrations that block arachidonic acid release. Our results indicate that human macrophages express cPLA2-alpha, iPLA2 and several sPLA2s. Cytosolic PLA2-alpha is the major enzyme responsible for lipid mediator production in human macrophages. PMID:19130898

  8. Long-term aerobic exercise increases redox-active iron through nitric oxide in rat hippocampus.

    PubMed

    Chen, Qian; Xiao, De-Sheng

    2014-01-30

    Adult hippocampus is highly vulnerable to iron-induced oxidative stress. Aerobic exercise has been proposed to reduce oxidative stress but the findings in the hippocampus are conflicting. This study aimed to observe the changes of redox-active iron and concomitant regulation of cellular iron homeostasis in the hippocampus by aerobic exercise, and possible regulatory effect of nitric oxide (NO). A randomized controlled study was designed in the rats with swimming exercise treatment (for 3 months) and/or an unselective inhibitor of NO synthase (NOS) (L-NAME) treatment. The results from the bleomycin-detectable iron assay showed additional redox-active iron in the hippocampus by exercise treatment. The results from nonheme iron content assay, combined with the redox-active iron content, showed increased storage iron content by exercise treatment. NOx (nitrate plus nitrite) assay showed increased NOx content by exercise treatment. The results from the Western blot assay showed decreased ferroportin expression, no changes of TfR1 and DMT1 expressions, increased IRP1 and IRP2 expression, increased expressions of eNOS and nNOS rather than iNOS. In these effects of exercise treatment, the increased redox-active iron content, storage iron content, IRP1 and IRP2 expressions were completely reversed by L-NAME treatment, and decreased ferroportin expression was in part reversed by L-NAME. L-NAME treatment completely inhibited increased NOx and both eNOS and nNOS expression in the hippocampus. Our findings suggest that aerobic exercise could increase the redox-active iron in the hippocampus, indicating an increase in the capacity to generate hydroxyl radicals through the Fenton reactions, and aerobic exercise-induced iron accumulation in the hippocampus might mainly result from the role of the endogenous NO.

  9. Effects of dietary combination of n-3 and n-9 fatty acids on the deposition of linoleic and arachidonic acid in broiler chicken meats.

    PubMed

    Shin, D; Choi, S H; Go, G; Park, J H; Narciso-Gaytán, C; Morgan, C A; Smith, S B; Sánchez-Plata, M X; Ruiz-Feria, C A

    2012-04-01

    To minimize the amount of n-6 fatty acids in broiler chicken meat, 120 Cobb × Ross male broilers were divided into 6 different groups and fed a basal corn-soybean meal diet containing 5% fat from 5 different lipid sources: 1) a commercial mix of animal and vegetable oil, 2) soybean oil and olive oil (2.5% each), 3) flaxseed oil and olive oil (2.5% each), 4) flaxseed oil, eicosapentaenoic acid (C20:5; EPA; n-3), and olive oil (2.45, 0.05, and 2.5% respectively; FEO), 5) flaxseed oil, docosahexaenoic acid (C22:6; DHA; n-3), and olive oil (2.45, 0.05, and 2.5% respectively; FDO), and 6) fish oil and olive oil (2.5% each; FHO). At 6 and 9 wk, one bird per pen (4 pens per treatment) was processed, and liver, breast, and thigh samples were collected and used for fatty acid profiles or Δ6- and Δ9-desaturase mRNA gene expression levels. The deposition of linoleic acid (C18:2; n-6) or arachidonic acid (C20:4; n-6) was decreased in breast and thigh muscles of chickens fed n-3 fatty acids for 9 wk compared with chickens fed animal and vegetable oil and soybean oil and olive oil diets (P < 0.05). The addition of EPA to the diet (FEO; P > 0.05) did not reduce the deposition of linoleic acid and arachidonic acid as much as DHA (FDO; P < 0.05), and it suppressed the expression of Δ6- and Δ9-desaturase. When EPA and DHA were blended (FHO) and supplied to broiler chickens for 9 wk, EPA and DHA combination effects were observed on the deposition of LA and arachidonic acid in breast and thigh muscles. Thereby, the addition of a mixed EPA and DHA to a broiler chicken diet may be recommendable to reduce arachidonic acid accumulation in both broiler chicken breast and thigh meats, providing a functional broiler chicken meat to consumers.

  10. Intake of farmed Atlantic salmon fed soybean oil increases hepatic levels of arachidonic acid-derived oxylipins and ceramides in mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction of vegetable ingredients in fish feed has affected the fatty acid composition in farmed Atlantic salmon (Salmo salar L). Here we investigated how changes in fish feed affected the metabolism of mice fed diets containing fillets from such farmed salmon. We demonstrate that replacement of...

  11. Effects of increasing docosahexaenoic acid and arachidonic acid in brood diets of monodactylus sebae on fecundity, egg and larval quality, and egg fatty acid composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Monodactylus sebae is a popular euryhaline ornamental fish species with limited aquaculture production. One of the bottlenecks to their commercial production has been knowledge of broodstock nutritional requirements. Therefore, three brood diets were formulated and fed to M. sebae brood to determine...

  12. [Effect of long-chain polyunsaturated fatty acids on arachidonate and docosahexaeonic acid in healthy infants in the first four months of life].

    PubMed

    Decsi, T; Szász, M; Sárkány, I; Botykai, A; Berthold, K

    1996-09-22

    Fatty acid compositions of plasma phospholipids (PL), triglycerides (TG) and sterol esters (STE) were measured by high resolution capillary gas-liquid chromatography in formula fed healthy infants at the ages of 5 days and 1, 2, 3 and 4 months. The infants were randomly assigned to receive either conventional infant formula (F, n = 10) without long-chain polyunsaturates (LCP) or the same formula supplemented with LCP (LCP-F, n = 12) in amounts and ratios similar to those characteristic to human milk. From the age of 1 month onwards, percentage contributions of the principal omega-6 LCP, arachidonic acid were significantly higher in plasma lipids of infants fed LCP-F than in those receiving conventional formula without dietary LCP. Values of the principal omega-3 LCP, docosahexaenoic acid were also significantly lower in the infants fed conventional formula than in those receiving LCP-F throughout the study. The data obtained indicate that from the formula supplemented with LCP both arachidonic and docosahexaenoic acids were effectively absorbed and incorporated into infantile plasma lipids. Recent data of the literature suggest that supplementation of infant formula with LCP may beneficially influence visual and psychomotor development also in healthy, term infants.

  13. Arachidonic acid pathway members PLA2G7, HPGD, EPHX2, and CYP4F8 identified as putative novel therapeutic targets in prostate cancer.

    PubMed

    Vainio, Paula; Gupta, Santosh; Ketola, Kirsi; Mirtti, Tuomas; Mpindi, John-Patrick; Kohonen, Pekka; Fey, Vidal; Perälä, Merja; Smit, Frank; Verhaegh, Gerald; Schalken, Jack; Alanen, Kalle A; Kallioniemi, Olli; Iljin, Kristiina

    2011-02-01

    The arachidonic acid and prostaglandin pathway has been implicated in prostate carcinogenesis, but comprehensive studies of the individual members in this key pathway are lacking. Here, we first conducted a systematic bioinformatic study of the expression of 36 arachidonic acid pathway genes across 9783 human tissue samples. The results showed that the PLA2G7, HPGD, EPHX2, and CYP4F8 genes are highly expressed in prostate cancer. Functional studies using RNA interference in prostate cancer cells indicated that all four genes are also essential for cell growth and survival. Clinical validation confirmed high PLA2G7 expression, especially in ERG oncogene-positive prostate cancers, and its silencing sensitized ERG-positive prostate cancer cells to oxidative stress. HPGD was highly expressed in androgen receptor (AR)-overexpressing advanced tumors, as well as in metastatic prostate cancers. EPHX2 mRNA correlated with AR in primary prostate cancers, and its inhibition in vitro reduced AR signaling and potentiated the effect of antiandrogen flutamide in cultured prostate cancer cells. In summary, we identified four novel putative therapeutic targets with biomarker potential for different subtypes of prostate cancer. In addition, our results indicate that inhibition of these enzymes may be particularly powerful when combined with other treatments, such as androgen deprivation or induction of oxidative stress. PMID:21281786

  14. Effects of graded levels of arachidonic acid on the reproductive physiology of Senegalese sole (Solea senegalensis): Fatty acid composition, prostaglandins and steroid levels in the blood of broodstock bred in captivity.

    PubMed

    Norambuena, Fernando; Estévez, Alicia; Mañanós, Evaristo; Bell, J Gordon; Carazo, Ignacio; Duncan, Neil

    2013-09-15

    Previous studies on Senegalese sole (Solea senegalensis) indicated that cultured broodstock (first generation, G1) have lower tissue levels of arachidonic acid (20:4n-6, ARA) than wild counterparts. ARA is metabolized to form prostaglandins (PGs) that are involved in steroid production and follicle maturation in fish. In the present study the effects of different dietary levels of ARA on blood lipid and fatty acid composition, prostaglandin (PGF2α, PGF3α, PGE2 and PGE3) levels and plasmatic steroid levels (11-ketotestosterone, 11-KT, testosterone, T and estradiol, E2) in G1 Senegalese sole were studied. For this purpose, 12 groups of ten fish (1:1 male and female), were fed six diets (each diets was fed to two groups) with different dietary ARA levels over nine months (diets A=0.7, B=1.6, C=2.3, D=3.2, E=5.0, F=6.0% ARA). ARA and CHOL levels in blood showed a significant increase in an ARA dose related manner (P<0.05) whereas EPA and EPA/ARA ratio were reduced. In males, steroid (11-KT and T) levels increased significantly with increasing dietary ARA in a dose dependent manner, whereas in females E2 did not show any change related to dietary ARA content. Plasma concentration of 3-series PGs (i.e., PGE3 and PGF3α) were reduced in parallel to increased ARA levels in blood (P<0.05) and levels of PGs 3-series were always higher than 2-series PGs (PGE2 and PGF2α). In conclusion there is an effect of dietary ARA on steroid production of Senegalese sole males, which might have important consequences in the reproduction of cultured fish.

  15. Production of arachidonic acid and dihomo-gamma-linolenic acid from glycerol by oil-producing filamentous fungi, Mortierella in the ARS culture collection.

    PubMed

    Hou, Ching T

    2008-06-01

    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 new uses for bioglycerin. We screened 12 Mortierella species: M. alpina NRRL 6302, M. claussenii NRRL 2760, M. elongata NRRL 5246, M. epigama NRRL 5512, M. humilis NRRL 6369, M. hygrophila NRRL 2591, M. minutissima NRRL 6462, M. multidivaricata NRRL 6456, M. nantahalensis NRRL 5216, M. parvispora NRRL 2941, M. sepedonioides NRRL 6425, and M. zychae NRRL 2592 for their production of arachidonic acid (AA) and dihomo-gamma-linolenic acid (DGLA) from glycerol. With glucose as substrate all of the strains tested produced AA and DGLA. The total fatty acid content of 125 mg/g cell dry weight (CDW) and fatty acid composition for AA (19.63%) and DGLA (5.95%) in the mycelia of M. alpina grown on glucose were comparable with those reported by Takeno et al. (Appl Environ Microbiol 71:5124-5128, 2005). With glycerol as substrate all species tested grew on glycerol and produced AA and DGLA except M. nantahalensis NRRL 5216, which could not grow on glycerol. The amount of AA and DGLA produced were comparable with those obtained with glucose-grown mycelia. The top five AA producers (mg AA/CDW) from glycerol were in the following order: M. parvispora>M. claussenii>M. alpina>M. zychae>M. minutissima. The top five dry mycelia weights were: M. zychae>M. epigama>M. hygrophila>M. humilis>M. minutissima. The top five species for total fatty acids production (mg/g CDW) were: M. claussenii>M. parvispora>M. minutissima>M. hygrophila>M. maltidivaricata. We selected two species, M. alpina and M. zychae for further studies with glycerol substrate. Their optimum production conditions were determined. Time course studies showed that the maximum cell growth and AA production for both

  16. Sustained increase in platelet aggregation after the cessation of clopidogrel.

    PubMed

    Djukanovic, Nina; Todorovic, Zoran; Zamaklar-Trifunovic, Danijela; Protic, Dragana; Dzudovic, Boris; Ostojic, Miodrag; Obradovic, Slobodan

    2016-02-01

    This study shows that the abrupt cessation of one-year clopidogrel treatment was not associated with thrombotic events in a prospective, multicentre study that enrolled 200 patients subjected to coronary stent implantation and treated with aspirin + clopidogrel 1 year after the stent placement. The aim of the study was to investigate the causes of a sustained increase of platelet aggregability, considering that the values of platelet aggregation stimulated with ADP + PGE1 (ADPHS values) significantly increased 10-90 days after the cessation of clopidogrel. Values of platelet aggregation induced by thrombin receptor activating peptide (TRAP values) and arachidonic acid (ASPI values) were divided into quartiles on the basis of ADPHS values 10 days after stopping clopidogrel (ADPHS10 ). There was a significant difference between TRAP values divided into quartiles according to ADPHS10 , 10, 45 and 90 days after stopping clopidogrel (P < 0.001, all), and ASPI values across the same quartiles 10 and 45 days after the cessation of clopidogrel (P = 0.028 and 0.003). The results of the study indicate that patients with early pronounced rebound phenomena to clopidogrel termination have a long-term (at least 90 days) increased platelet aggregation to other agonists such as thrombin-related activated protein and arachidonic acid, suggesting the complex mutual relationship of various factors/agonists influencing the function of platelets. PMID:26515635

  17. Decreased Polyunsaturated Fatty Acid Content Contributes to Increased Survival in Human Colon Cancer

    PubMed Central

    Oraldi, Manuela; Trombetta, Antonella; Biasi, Fiorella; Canuto, Rosa A.; Maggiora, Marina; Muzio, Giuliana

    2009-01-01

    Among diet components, some fatty acids are known to affect several stages of colon carcinogenesis, whereas others are probably helpful in preventing tumors. In light of this, our aim was to determine the composition of fatty acids and the possible correlation with apoptosis in human colon carcinoma specimens at different Duke's stages and to evaluate the effect of enriching human colon cancer cell line with the possible reduced fatty acid(s). Specimens of carcinoma were compared with the corresponding non-neoplastic mucosa: a significant decrease of arachidonic acid, PPARα, Bad, and Bax and a significant increase of COX-2, Bcl-2, and pBad were found. The importance of arachidonic acid in apoptosis was demonstrated by enriching a Caco-2 cell line with this fatty acid. It induced apoptosis in a dose- and time-dependent manner via induction of PPARα that, in turn, decreased COX-2. In conclusion, the reduced content of arachidonic acid is likely related to carcinogenic process decreasing the susceptibility of cancer cells to apoptosis. PMID:19841681

  18. Selective activation of the gamma-subspecies of protein kinase C from bovine cerebellum by arachidonic acid and its lipoxygenase metabolites.

    PubMed

    Shearman, M S; Naor, Z; Sekiguchi, K; Kishimoto, A; Nishizuka, Y

    1989-01-30

    The gamma-subspecies of protein kinase C (PKC) apparently is expressed only in central nervous tissues, and at a high level in the cerebellum and hippocampus. gamma-PKC from bovine cerebellum, but not the alpha- or beta I/beta II-subspecies, is activated by micromolar concentrations of arachidonic acid (AA), in the absence of both phospholipid and diacylglycerol. A significant component of this activation is also calcium independent. Other unsaturated fatty acids are much less active in this respect. Among the AA metabolites tested, lipoxin A (5(S),6(R),15(S)-11-cis-isomer) was a potent, selective activator of the gamma-subspecies, and also, to a lesser extent, 12(S)-hydroxy-5,8,10,14-eicosatetraenoic acid could support activation. These results raise the possibility that AA and some of its lipoxygenase metabolites may function as messenger molecules in neurones to activate the gamma-subspecies of PKC. PMID:2492951

  19. The effect of non-steroidal anti-inflammatory drugs on the metabolism of 14C-arachidonic acid by human gingival tissue in vitro.

    PubMed

    Elattar, T M; Lin, H S; Tira, D E

    1983-09-01

    We investigated the effect of non-steroidal anti-inflammatory drugs on prostaglandins (PGs) and 12-hydroxyeicosatetraenoic acid (12-HETE) formation by inflamed human gingival tissues. Gingival tissue homogenates were incubated with 14C-arachidonic acid in the presence of indomethacin, piroxicam, or ibuprofen, and the organic solvent extracts were chromatographed on silica gel plates with standards for radiometric assay. There was a significant negative trend between the doses (10(-7)-10(-3) M) of each of indomethacin, piroxicam, and ibuprofen, and the amounts of PGF2 alpha, PGE2, PGD2, and 15-keto-PGE2 produced. All three drugs have a significant inhibitory effect on PGs and 12-HETE production at 10(-3) M when compared with the control. The rank order effectiveness of the drugs, at 10(-3) M, on PG inhibition was indomethacin greater than piroxicam greater than ibuprofen, and on 12-HETE inhibition was indomethacin greater than ibuprofen greater than piroxicam.

  20. Role of intramitochondrial arachidonic acid and acyl-CoA synthetase 4 in angiotensin II-regulated aldosterone synthesis in NCI-H295R adrenocortical cell line.

    PubMed

    Mele, Pablo G; Duarte, Alejandra; Paz, Cristina; Capponi, Alessandro; Podestá, Ernesto J

    2012-07-01

    Although the role of arachidonic acid (AA) in angiotensin II (ANG II)- and potassium-stimulated steroid production in zona glomerulosa cells is well documented, the mechanism responsible for AA release is not fully described. In this study we evaluated the mechanism involved in the release of intramitochondrial AA and its role in the regulation of aldosterone synthesis by ANG II in glomerulosa cells. We show that ANG II and potassium induce the expression of acyl-coenzyme A (CoA) thioesterase 2 and acyl-CoA synthetase 4, two enzymes involved in intramitochondrial AA generation/export system well characterized in other steroidogenic systems. We demonstrate that mitochondrial ATP is required for AA generation/export system, steroid production, and steroidogenic acute regulatory protein induction. We also demonstrate the role of protein tyrosine phosphatases regulating acyl-CoA synthetase 4 and steroidogenic acute regulatory protein induction, and hence ANG II-stimulated aldosterone synthesis.

  1. A rapid method for determining arachidonic:eicosapentaenoic acid ratios in whole blood lipids: correlation with erythrocyte membrane ratios and validation in a large Italian population of various ages and pathologies

    PubMed Central

    2010-01-01

    Background Omega-3 and -6 polyunsaturated fatty acids (LCPUFA), are important for good health conditions. They are present in membrane phospholipids. The ratio of total n-6:n-3 LCPUFA and arachidonic acid:eicosapentaenoic acid (AA and EPA), should not exceed 5:1. Increased intake of n-6 and decreased consumption of n-3 has resulted in much higher, ca 10/15:1 ratio in RBC fatty acids with the possible appearance of a pathological "scenario". The determination of RBC phospholipid LCPUFA contents and ratios is the method of choice for assessing fatty acid status but it is labour intensive and time consuming. Aims of the study [i] To describe and validate a rapid method, suitable for large scale population studies, for total blood fatty acid assay; [ii] to verify a possible correlation between total n-6:n-3 ratio and AA:EPA ratios in RBC phospholipids and in whole-blood total lipids, [iii] to assess usefulness of these ratio as biomarkers of LCPUFA status. Methods [1] Healthy volunteers and patients with various pathologies were recruited. [2] Fatty acid analyses by GC of methyl esters from directly derivatized whole blood total lipids and from RBC phospholipids were performed on fasting blood samples from 1432 subjects categorised according to their age, sex and any existing pathologies. AA:EPA ratio and the total n-6:n-3 ratio were determined. Results AA:EPA ratio is a more sensitive and reliable index for determining changes in total blood fatty acid and it is correlated with the ratio derived from extracted RBC phospholipids. Conclusions The described AA:EPA ratio is a simple, rapid and reliable method for determining n-3 fatty acid status. PMID:20105293

  2. The effect of dietary arachidonic acid (ARA) on growth performance, fatty acid composition and expression of ARA metabolism-related genes in larval half-smooth tongue sole (Cynoglossus semilaevis).

    PubMed

    Yuan, Yuhui; Li, Songlin; Mai, Kangsen; Xu, Wei; Zhang, Yanjiao; Ai, Qinghui

    2015-05-28

    The present study was conducted to investigate the effects of dietary arachidonic acid (ARA) on growth performance, fatty acid composition and ARA metabolism-related gene expression in larval half-smooth tongue sole (Cynoglossus semilaevis). Larvae (35 d after hatching, 54 (SEM 1) mg) were fed diets with graded concentrations of ARA (0.01, 0.39, 0.70, 1.07, 1.42 and 2.86 % dry weight) five times per d to apparent satiation for 30 d. Results showed that increased dietary ARA concentration caused a significant non-linear rise to a plateau in survival rate, final body weight and thermal growth coefficient, and the maximum values occurred with the 1.42 % ARA treatment. As dietary ARA increased to 1.07 or 1.42 %, activities of trypsin, leucine aminopeptidase and alkaline phosphatase levels increased, but they decreased with higher ARA concentrations. The fatty acid composition of tongue sole larvae was almost well correlated with their dietary fatty acid profiles, and the EPA content of the larvae decreased with increasing dietary ARA. Meanwhile, the partial sequences of COX-1a (cyclo-oxygenase-1a), COX-1b (cyclo-oxygenase-1b), COX-2 (cyclo-oxygenase-2), 5-LOX (5-lipoxygenase) and CYP2J6-like (cytochrome P450 2J6-like) were also obtained. Both COX-2 and 5-LOX mRNA expression levels significantly increased to a plateau in an 'L'-shaped manner as dietary ARA increased to 1.07 or 1.42 %, but no significant differences were found in the gene expression of COX-1a, COX-1b or CYP2J6-like. These results suggest that 1.07-1.42 % dietary ARA was beneficial to the growth performance of larval tongue sole, and the regulation of dietary ARA on the growth performance of larvae was probably involved in altering the mRNA expression of COX-2 and 5-LOX.

  3. Increased EETs participate in peripheral endothelial dysfunction of cirrhosis

    PubMed Central

    Sacerdoti, David; Mania, Despina; Jiang, Houli; Pesce, Paola; Gaiani, Silvia; Gatta, Angelo; Bolognesi, Massimo

    2015-01-01

    The hyperdynamic circulation of cirrhosis participates in the pathophysiology of portal hypertension. P450-dependent epoxyeicosatrienoic acids (EET) are potent vasodilators. We evaluated plasma levels of EETs in cirrhotic patients and the effect of epoxygenase and nitric oxide synthase (NOS) inhibition on skin blood flow, measured by laser Doppler flowmetry, in normal subjects and cirrhotic patients with and without ascites. Free plasma EETs were increased in cirrhotic patients compared to normal subjects, while the ratio between 8,9-, 11,12-, and 14-15-EET was the same. In cirrhotic patients without ascites, skin blood flow was significantly increased compared to normal subjects. In patients with ascites skin blood flow was significantly reduced compared to control subjects and patients without ascites. Inhibition of epoxygenase with miconazole and of NOS with L-NG-Nitroarginine methyl ester (L-NAME) decreased basal skin flow in normal subjects and in cirrhotic patients, the effect being higher in cirrhotic patients. Miconazole caused a further decrease in flow when administered with L-NAME, both in normal subjects and in cirrhotic patients. In conclusion, EETs participate in the control of peripheral circulation of normal subjects and in the pathophysiology of peripheral vasodilatation of cirrhotic patients with ascites. PMID:22245571

  4. Increased pulmonary arteriolar tone associated with lung oxidative stress and nitric oxide in a mouse model of Alzheimer's disease.

    PubMed

    Roberts, Andrew M; Jagadapillai, Rekha; Vaishnav, Radhika A; Friedland, Robert P; Drinovac, Robert; Lin, Xingyu; Gozal, Evelyne

    2016-09-01

    Vascular dysfunction and decreased cerebral blood flow are linked to Alzheimer's disease (AD). Loss of endothelial nitric oxide (NO) and oxidative stress in human cerebrovascular endothelium increase expression of amyloid precursor protein (APP) and enhance production of the Aβ peptide, suggesting that loss of endothelial NO contributes to AD pathology. We hypothesize that decreased systemic NO bioavailability in AD may also impact lung microcirculation and induce pulmonary endothelial dysfunction. The acute effect of NO synthase (NOS) inhibition on pulmonary arteriolar tone was assessed in a transgenic mouse model (TgAD) of AD (C57BL/6-Tg(Thy1-APPSwDutIowa)BWevn/Mmjax) and age-matched wild-type controls (C57BL/6J). Arteriolar diameters were measured before and after the administration of the NOS inhibitor, L-NAME Lung superoxide formation (DHE) and formation of nitrotyrosine (3-NT) were assessed as indicators of oxidative stress, inducible NOS (iNOS) and tumor necrosis factor alpha (TNF-α) expression as indicators of inflammation. Administration of L-NAME caused either significant pulmonary arteriolar constriction or no change from baseline tone in wild-type (WT) mice, and significant arteriolar dilation in TgAD mice. DHE, 3-NT, TNF-α, and iNOS expression were higher in TgAD lung tissue, compared to WT mice. These data suggest L-NAME could induce increased pulmonary arteriolar tone in WT mice from loss of bioavailable NO In contrast, NOS inhibition with L-NAME had a vasodilator effect in TgAD mice, potentially caused by decreased reactive nitrogen species formation, while significant oxidative stress and inflammation were present. We conclude that AD may increase pulmonary microvascular tone as a result of loss of bioavailable NO and increased oxidative stress. Our findings suggest that AD may have systemic microvascular implications beyond central neural control mechanisms.

  5. Hypertonicity increases NO production to modulate the firing rate of magnocellular neurons of the supraoptic nucleus of rats.

    PubMed

    da Silva, M P; Ventura, R R; Varanda, W A

    2013-10-10

    Increases in plasma osmolality enhance nitric oxide (NO) levels in magnocellular neurosecretory cells (MNCs) of the supraoptic nucleus (SON) and modulate the secretion of both vasopressin (VP) and oxytocin (OT). In this paper, we describe the effects of hypertonicity on the electrical properties of MNCs by focusing on the nitrergic modulation of their activity in this condition. Membrane potentials were measured using the patch clamp technique, in the presence of both glutamatergic and GABAergic neurotransmission blockers, in coronal brain slices of male Wistar rats. The recordings were first made under a control condition (295 mosm/kg H2O), then in the presence of a hypertonic stimulus (330 mosm/kg H2O) and, finally, with a hypertonic stimulus plus 500 μM L-Arginine or 100 μM N-nitro-L-Arginine methyl ester hydrochloride (L-NAME). Hypertonicity per se increased the firing frequency of the neurons. L-Arginine prevented the increase in fire frequency induced by hypertonic stimulus, and L-NAME (inhibitor of nitric oxide synthase) induced an additional increase in frequency when applied together with the hypertonic solution. Moreover, L-Arginine hyperpolarizes the resting potential and decreases the peak value of the after-hyperpolarization; both effects were blocked by L-NAME and hypertonicity and/or L-NAME reduced the time constant of the rising phase of the after-depolarization. These results demonstrate that an intrinsic nitrergic system is part of the mechanisms controlling the excitability of MNCs of the SON when the internal fluid homeostasis is disturbed. PMID:23850590

  6. Increased pulmonary arteriolar tone associated with lung oxidative stress and nitric oxide in a mouse model of Alzheimer's disease.

    PubMed

    Roberts, Andrew M; Jagadapillai, Rekha; Vaishnav, Radhika A; Friedland, Robert P; Drinovac, Robert; Lin, Xingyu; Gozal, Evelyne

    2016-09-01

    Vascular dysfunction and decreased cerebral blood flow are linked to Alzheimer's disease (AD). Loss of endothelial nitric oxide (NO) and oxidative stress in human cerebrovascular endothelium increase expression of amyloid precursor protein (APP) and enhance production of the Aβ peptide, suggesting that loss of endothelial NO contributes to AD pathology. We hypothesize that decreased systemic NO bioavailability in AD may also impact lung microcirculation and induce pulmonary endothelial dysfunction. The acute effect of NO synthase (NOS) inhibition on pulmonary arteriolar tone was assessed in a transgenic mouse model (TgAD) of AD (C57BL/6-Tg(Thy1-APPSwDutIowa)BWevn/Mmjax) and age-matched wild-type controls (C57BL/6J). Arteriolar diameters were measured before and after the administration of the NOS inhibitor, L-NAME Lung superoxide formation (DHE) and formation of nitrotyrosine (3-NT) were assessed as indicators of oxidative stress, inducible NOS (iNOS) and tumor necrosis factor alpha (TNF-α) expression as indicators of inflammation. Administration of L-NAME caused either significant pulmonary arteriolar constriction or no change from baseline tone in wild-type (WT) mice, and significant arteriolar dilation in TgAD mice. DHE, 3-NT, TNF-α, and iNOS expression were higher in TgAD lung tissue, compared to WT mice. These data suggest L-NAME could induce increased pulmonary arteriolar tone in WT mice from loss of bioavailable NO In contrast, NOS inhibition with L-NAME had a vasodilator effect in TgAD mice, potentially caused by decreased reactive nitrogen species formation, while significant oxidative stress and inflammation were present. We conclude that AD may increase pulmonary microvascular tone as a result of loss of bioavailable NO and increased oxidative stress. Our findings suggest that AD may have systemic microvascular implications beyond central neural control mechanisms. PMID:27604401

  7. ABA Suppresses Botrytis cinerea Elicited NO Production in Tomato to Influence H2O2 Generation and Increase Host Susceptibility

    PubMed Central

    Sivakumaran, Anushen; Akinyemi, Aderemi; Mandon, Julian; Cristescu, Simona M.; Hall, Michael A.; Harren, Frans J. M.; Mur, Luis A. J.

    2016-01-01

    Abscisic acid (ABA) production has emerged a susceptibility factor in plant-pathogen interactions. This work examined the interaction of ABA with nitric oxide (NO) in tomato following challenge with the ABA-synthesizing pathogen, Botrytis cinerea. Trace gas detection using a quantum cascade laser detected NO production within minutes of challenge with B. cinerea whilst photoacoustic laser detection detected ethylene production – an established mediator of defense against this pathogen – occurring after 6 h. Application of the NO generation inhibitor N-Nitro-L-arginine methyl ester (L-NAME) suppressed both NO and ethylene production and resistance against B. cinerea. The tomato mutant sitiens fails to accumulate ABA, shows increased resistance to B. cinerea and we noted exhibited elevated NO and ethylene production. Exogenous application of L-NAME or ABA reduced NO production in sitiens and reduced resistance to B. cinerea. Increased resistance to B. cinerea in sitiens have previously been linked to increased reactive oxygen species (ROS) generation but this was reduced in both L-NAME and ABA-treated sitiens. Taken together, our data suggests that ABA can decreases resistance to B. cinerea via reduction of NO production which also suppresses both ROS and ethylene production. PMID:27252724

  8. ABA Suppresses Botrytis cinerea Elicited NO Production in Tomato to Influence H2O2 Generation and Increase Host Susceptibility.

    PubMed

    Sivakumaran, Anushen; Akinyemi, Aderemi; Mandon, Julian; Cristescu, Simona M; Hall, Michael A; Harren, Frans J M; Mur, Luis A J

    2016-01-01

    Abscisic acid (ABA) production has emerged a susceptibility factor in plant-pathogen interactions. This work examined the interaction of ABA with nitric oxide (NO) in tomato following challenge with the ABA-synthesizing pathogen, Botrytis cinerea. Trace gas detection using a quantum cascade laser detected NO production within minutes of challenge with B. cinerea whilst photoacoustic laser detection detected ethylene production - an established mediator of defense against this pathogen - occurring after 6 h. Application of the NO generation inhibitor N-Nitro-L-arginine methyl ester (L-NAME) suppressed both NO and ethylene production and resistance against B. cinerea. The tomato mutant sitiens fails to accumulate ABA, shows increased resistance to B. cinerea and we noted exhibited elevated NO and ethylene production. Exogenous application of L-NAME or ABA reduced NO production in sitiens and reduced resistance to B. cinerea. Increased resistance to B. cinerea in sitiens have previously been linked to increased reactive oxygen species (ROS) generation but this was reduced in both L-NAME and ABA-treated sitiens. Taken together, our data suggests that ABA can decreases resistance to B. cinerea via reduction of NO production which also suppresses both ROS and ethylene production. PMID:27252724

  9. Tranilast Increases Vasodilator Response to Acetylcholine in Rat Mesenteric Resistance Arteries through Increased EDHF Participation

    PubMed Central

    Sastre, Esther; Caracuel, Laura; Callejo, María; Balfagón, Gloria

    2014-01-01

    Background and Purpose Tranilast, in addition to its capacity to inhibit mast cell degranulation, has other biological effects, including inhibition of reactive oxygen species, cytokines, leukotrienes and prostaglandin release. In the current study, we analyzed whether tranilast could alter endothelial function in rat mesenteric resistance arteries (MRA). Experimental Approach Acetylcholine-induced relaxation was analyzed in MRA (untreated and 1-hour tranilast treatment) from 6 month-old Wistar rats. To assess the possible participation of endothelial nitric oxide or prostanoids, acetylcholine-induced relaxation was analyzed in the presence of L-NAME or indomethacin. The participation of endothelium-derived hyperpolarizing factor (EDHF) in acetylcholine-induced response was analyzed by preincubation with TRAM-34 plus apamin or by precontraction with a high K+ solution. Nitric oxide (NO) and superoxide anion levels were measured, as well as vasomotor responses to NO donor DEA-NO and to large conductance calcium-activated potassium channel opener NS1619. Key Results Acetylcholine-induced relaxation was greater in tranilast-incubated MRA. Acetylcholine-induced vasodilation was decreased by L-NAME in a similar manner in both experimental groups. Indomethacin did not modify vasodilation. Preincubation with a high K+ solution or TRAM-34 plus apamin reduced the vasodilation to ACh more markedly in tranilast-incubated segments. NO and superoxide anion production, and vasodilator responses to DEA-NO or NS1619 remained unmodified in the presence of tranilast. Conclusions and Implications Tranilast increased the endothelium-dependent relaxation to acetylcholine in rat MRA. This effect is independent of the nitric oxide and cyclooxygenase pathways but involves EDHF, and is mediated by an increased role of small conductance calcium-activated K+ channels. PMID:24992476

  10. Isoliquiritigenin induces growth inhibition and apoptosis through downregulating arachidonic acid metabolic network and the deactivation of PI3K/Akt in human breast cancer

    SciTech Connect

    Li, Ying; Zhao, Haixia; Wang, Yuzhong; Zheng, Hao; Yu, Wei; Chai, Hongyan; Zhang, Jing; Falck, John R.; Guo, Austin M.; Yue, Jiang; Peng, Renxiu; Yang, Jing

    2013-10-01

    Arachidonic acid (AA)-derived eicosanoids and its downstream pathways have been demonstrated to play crucial roles in growth control of breast cancer. Here, we demonstrate that isoliquiritigenin, a flavonoid phytoestrogen from licorice, induces growth inhibition and apoptosis through downregulating multiple key enzymes in AA metabolic network and the deactivation of PI3K/Akt in human breast cancer. Isoliquiritigenin diminished cell viability, 5-bromo-2′-deoxyuridine (BrdU) incorporation, and clonogenic ability in both MCF-7 and MDA-MB-231cells, and induced apoptosis as evidenced by an analysis of cytoplasmic histone-associated DNA fragmentation, flow cytometry and hoechst staining. Furthermore, isoliquiritigenin inhibited mRNA expression of multiple forms of AA-metabolizing enzymes, including phospholipase A2 (PLA2), cyclooxygenases (COX)-2 and cytochrome P450 (CYP) 4A, and decreased secretion of their products, including prostaglandin E{sub 2} (PGE{sub 2}) and 20-hydroxyeicosatetraenoic acid (20-HETE), without affecting COX-1, 5-lipoxygenase (5-LOX), 5-lipoxygenase activating protein (FLAP), and leukotriene B{sub 4} (LTB{sub 4}). In addition, it downregulated the levels of phospho-PI3K, phospho-PDK (Ser{sup 241}), phospho-Akt (Thr{sup 308}), phospho-Bad (Ser{sup 136}), and Bcl-x{sub L} expression, thereby activating caspase cascades and eventually cleaving poly(ADP-ribose) polymerase (PARP). Conversely, the addition of exogenous eicosanoids, including PGE{sub 2}, LTB{sub 4} and a 20-HETE analog (WIT003), and caspase inhibitors, or overexpression of constitutively active Akt reversed isoliquiritigenin-induced apoptosis. Notably, isoliquiritigenin induced growth inhibition and apoptosis of MDA-MB-231 human breast cancer xenografts in nude mice, together with decreased intratumoral levels of eicosanoids and phospho-Akt (Thr{sup 308}). Collectively, these data suggest that isoliquiritigenin induces growth inhibition and apoptosis through downregulating AA metabolic

  11. Effect of dietary enrichment with n-3 polyunsaturated fatty acids (PUFA) or n-9 PUFA on arachidonate metabolism in vivo and experimentally induced inflammation in mice.

    PubMed

    Doshi, Masaru; Watanabe, Shiro; Niimoto, Tsuyoshi; Kawashima, Hiroshi; Ishikura, Yoshiyuki; Kiso, Yoshinobu; Hamazaki, Tomohito

    2004-03-01

    Mice were fed a diet supplemented with palm oil (control diet), n-3 polyunsaturated fatty acids (PUFA)-, or n-9 PUFA-rich oil for 3 weeks. The n-3 PUFA-rich diet suppressed the generation of both leukotrienes (LT) and prostaglandins (PG), but the n-9 PUFA-rich diet did LT but not PG generation during acute inflammation. Leukocyte accumulation during acute inflammation was not different in the n-3 or n-9 PUFA-rich diet group as compared with the control group. The n-3 PUFA-rich diet but not the n-9 PUFA-rich diet suppressed Freund's adjuvant-induced granuloma formation. The n-9 PUFA-rich diet significantly attenuated galactosamine/lipopolysaccharide-induced liver injury more effectively than the n-3 PUFA-rich diet as compared with the control diet. The present study revealed the differential modification of experimentally induced inflammation in mice by dietary n-3 PUFA and n-9 PUFA, which may be due to their different effects on 5-lipoxygenease and cyclooxygenase metabolism of arachidonic acid during inflammatory processes.

  12. Menopause-induced uterine epithelium atrophy results from arachidonic acid/prostaglandin E2 axis inhibition-mediated autophagic cell death

    PubMed Central

    Zhou, Shengtao; Zhao, Linjie; Yi, Tao; Wei, Yuquan; Zhao, Xia

    2016-01-01

    Women experience menopause later in life. Menopause is characterized by dramatically decreased circulating estrogen level secondary to loss of ovarian function and atrophic state of genital organs. However, the molecular mechanisms for this process are not fully understood. In this study, we aimed to investigate the potential molecular mechanisms that underlie menopause-induced uterine endometrial atrophy. Our data showed that autophagy was activated in the uterine epithelial cells of both ovariectomized rats and peri-menopausal females. Endoplasmic reticulum (ER) stress occurred even prior to autophagy induction. Integrated bioinformatics analysis revealed that ER stress induced downstream decreased release of arachidonic acid (AA) and downregulation of AA/prostaglandin E2 (PGE2) axis, which led to Akt/mTOR signaling pathway inactivation. Consequently, autophagosomes were recruited and LC3-dependent autophagy was induced in uterine epithelial cells. Treatment with exogenous E2, PGE2, salubrinal or RNAi-mediated silencing of key autophagy genes could effectively counteract estrogen depletion-induced autophagy. Collectively, autophagy is a critical regulator of the uterine epithelium that accounts for endometrial atrophy after menopause. PMID:27506466

  13. Menopause-induced uterine epithelium atrophy results from arachidonic acid/prostaglandin E2 axis inhibition-mediated autophagic cell death.

    PubMed

    Zhou, Shengtao; Zhao, Linjie; Yi, Tao; Wei, Yuquan; Zhao, Xia

    2016-01-01

    Women experience menopause later in life. Menopause is characterized by dramatically decreased circulating estrogen level secondary to loss of ovarian function and atrophic state of genital organs. However, the molecular mechanisms for this process are not fully understood. In this study, we aimed to investigate the potential molecular mechanisms that underlie menopause-induced uterine endometrial atrophy. Our data showed that autophagy was activated in the uterine epithelial cells of both ovariectomized rats and peri-menopausal females. Endoplasmic reticulum (ER) stress occurred even prior to autophagy induction. Integrated bioinformatics analysis revealed that ER stress induced downstream decreased release of arachidonic acid (AA) and downregulation of AA/prostaglandin E2 (PGE2) axis, which led to Akt/mTOR signaling pathway inactivation. Consequently, autophagosomes were recruited and LC3-dependent autophagy was induced in uterine epithelial cells. Treatment with exogenous E2, PGE2, salubrinal or RNAi-mediated silencing of key autophagy genes could effectively counteract estrogen depletion-induced autophagy. Collectively, autophagy is a critical regulator of the uterine epithelium that accounts for endometrial atrophy after menopause. PMID:27506466

  14. LC-MS/MS for the simultaneous analysis of arachidonic acid and 32 related metabolites in human plasma: Basal plasma concentrations and aspirin-induced changes of eicosanoids.

    PubMed

    Shinde, Dhananjay D; Kim, Kwon-Bok; Oh, Kyung-Suk; Abdalla, Nagi; Liu, Kwang-Hyeon; Bae, Soo Kyung; Shon, Ji-Hong; Kim, Ho-Sook; Kim, Dong-Hyun; Shin, Jae Gook

    2012-12-12

    Eicosanoids play an important role in various biological responses and can be used as biomarkers for specific diseases. Therefore, we developed a highly selective, sensitive, and robust liquid chromatography-tandem mass spectrometric method to measure arachidonic acid and its 32 metabolites in human plasma. Sample preparation involved solid phase extraction, which efficiently removed sources of interference present in human plasma. Chromatographic separation was performed using a Luna C(8)-column with 0.5mM ammonium formate buffer and acetonitrile as the mobile phase under gradient conditions. Detection was performed using tandem mass spectrometry equipped with an electrospray ionization interface in negative ion mode. The matrix did not affect the reproducibility and reliability of the assay. All analytes showed good linearity over the investigated concentration range (r>0.997). The validated lower limit of quantitation for the analytes ranged from 10 to 400pg/mL. Intra- and inter-day precision (RDS%) over the concentration ranges for all eicosanoids were within 16.8%, and accuracy ranged between 88.1 and 108.2%. This assay was suitable for the determination of basal plasma levels of eicosanoids and the evaluation of effect of aspirin on eicosanoid plasma levels in healthy subjects. PMID:23217314

  15. Evidence for the essentiality of arachidonic and docosahexaenoic acid in the postnatal maternal and infant diet for the development of the infant's immune system early in life.

    PubMed

    Richard, Caroline; Lewis, Erin D; Field, Catherine J

    2016-05-01

    Long-chain polyunsaturated fatty acids (LCPUFA), especially the balance between arachidonic (AA) and docosahexaenoic (DHA) acids are known to have important immunomodulatory roles during the postnatal period when the immune system is rapidly developing. AA and DHA are required in infant formula in many countries but are optional in North America. The rationale for adding these LCPUFA to full-term formula is based on their presence in breast milk and randomized controlled studies that suggest improved cognitive function in preterm infants, but results are more variable in full-term infants. Recently, the European Food Safety Authority has proposed, based on a lack of functional evidence, that AA is not required in infant formula for full-term infants during the first year of life but DHA should remain mandatory. The purpose of this review is to review the evidence from epidemiological and intervention studies regarding the essentiality of AA and DHA in the postnatal infant and maternal diet (breast-feeding) for the immune system development early in life. Although studies support the essentiality of DHA for the immune system development, more research is needed to rule out the essentiality of AA. Nevertheless, intervention studies have demonstrated improvement in many markers of immune function in infants fed formula supplemented with AA and DHA compared with unsupplemented formula, which appears to consistently result in beneficial health outcomes including reduction in the risk of developing allergic and atopic disease early in life.

  16. Computational insight into the catalytic implication of head/tail-first orientation of arachidonic acid in human 5-lipoxygenase: consequences for the positional specificity of oxygenation.

    PubMed

    Saura, Patricia; Maréchal, Jean-Didier; Masgrau, Laura; Lluch, José M; González-Lafont, Àngels

    2016-08-17

    In the present work we have combined homology modeling, protein-ligand dockings, quantum mechanics/molecular mechanics calculations and molecular dynamics simulations to generate human 5-lipoxygenase (5-LOX):arachidonic acid (AA) complexes consistent with the 5-lipoxygenating activity (which implies hydrogen abstraction at the C7 position). Our results suggest that both the holo and the apo forms of human Stable 5-LOX could accommodate AA in a productive form for 5-lipoxygenation. The former, in a tail-first orientation, with the AA carboxylate end interacting with Lys409, gives the desired structures with C7 close to the Fe-OH(-) cofactor and suitable barrier heights for H7 abstraction. Only when using the apo form structure, a head-first orientation with the AA carboxylate close to His600 (a residue recently proposed as essential for AA positioning) is obtained in the docking calculations. However, the calculated barrier heights for this head-first orientation are in principle consistent with 5-LOX specificity, but also with 12/8 regioselectivity. Finally, long MD simulations give support to the recent hypothesis that the Phe177 + Tyr181 pair needs to close the active site access during the chemical reaction, and suggest that in the case of a head-first orientation Phe177 may be the residue interacting with the AA carboxylate. PMID:27489112

  17. Identification of a cyclooxygenase gene from the red alga Gracilaria vermiculophylla and bioconversion of arachidonic acid to PGF(2α) in engineered Escherichia coli.

    PubMed

    Kanamoto, Hirosuke; Takemura, Miho; Ohyama, Kanji

    2011-08-01

    Prostaglandins (PGs) are important local messenger molecules in many tissues and organs of animals including human. For applications in medicine and animal care, PGs are mostly purified from animal tissues or chemically synthesized. To generate a clean, reliable, and inexpensive source for PGs, we have now engineered expression of a suitable cyclooxygenase gene in Escherichia coli and achieved production levels of up to 2.7 mg l(-1) PGF(2α). The cyclooxygenase gene cloned from the red alga Gracilaria vermiculophylla appears to be fully functional without any eukaryotic modifications in E. coli. A crude extract of the recombinant E. coli cells is able to convert in vitro the substrate arachidonic acid (AA) to PGF(2α). Furthermore, these E. coli cells produced PGF(2α) in a medium supplemented with AA and secreted the PGF(2α) product. To our knowledge, this is the first report of the functional expression of a cyclooxygenase gene and concomitant production of PGF(2α) in E. coli. The successful microbial synthesis of PGs with reliable yields promises a novel pharmaceutical tool to produce PGF(2α) at significantly reduced prices and greater purity.

  18. The role of the arachidonic acid cascade in the species-specific X-ray-induced inflammation of the rabbit eye

    SciTech Connect

    Bito, L.Z.; Klein, E.M.

    1982-05-01

    To identify the mediator(s) of the apparently species-specific X-ray-induced inflammation of the rabbit eye, inhibitors of the synthesis and/or release of known or putative mediators of ocular inflammation were administered prior to irradiation. The X-ray-induced ocular inflammation, particularly the rise in intraocular pressure, was found to be inhibited by intravenous pretreatment of rabbits with flurbiprofen, indomethacin, or imidazole (1, 10, and 100 mg/kg i.v., respectively), or by combined intravitreal and topical administration of flurbiprofen. Systemic, intravitreal, and/or topical pretreatment with prednisolone or disodium cromoglycate or the retrobulbar injection of ethyl alcohol or capsaicin failed to block the inflammatory response, whereas vitamin E apparently exerted some protective effect. These findings show that the X-ray-induced inflammation of the rabbit eye is mediated, at least in part, by prostaglandins (PGs) and/or related autacoids. In addition, these results suggest that the unique sensitivity of the rabbit eye to X-ray-induced inflammation is due either to the presence in this species of a unique or uniquely effective triggering mechanism for the release of PG precursors or to the greater sensitivity of this species to the ocular inflammatory effects of PGs. Thus the rabbit eye may provide a unique model for studying some aspects of arachidonic acid release or ocular PG effects, but extreme caution must be exercised in generalizing such findings to other species.

  19. Transient postnatal fluoxetine decreases brain concentrations of 20-HETE and 15-epi-LXA4, arachidonic acid metabolites in adult mice

    PubMed Central

    Yuan, Zhi-Xin; Rapoport, Stanley I

    2015-01-01

    Background Transient postnatal exposure of rodents to the selective serotonin (5-HT) reuptake inhibitor (SSRI) fluoxetine alters behavior and brain 5-HT neurotransmission during adulthood, and also reduces brain arachidonic (ARA) metabolic consumption and protein level of the ARA metabolizing enzyme, cytochrome P4504A (CYP4A). Hypothesis Brain 20-hydroxyeicosatetraenoic acid (20-HETE), converted by CYP4A from ARA, will be reduced in adult mice treated transiently and postnatally with fluoxetine. Methods Male mice pups were injected i.p. daily with fluoxetine (10 mg/kg) or saline during P4-P21. At P90 their brain was high-energy microwaved and analyzed for 20-HETE and six other ARA metabolites by enzyme immunoassay. Results Postnatal fluoxetine vs. saline significantly decreased brain concentrations of 20-HETE (−70.3%) and 15-epi-lipoxin A4 (−60%) in adult mice, but did not change other eicosanoid concentrations. Conclusions Transient postnatal administration of fluoxetine to mice results in reduced brain ARA metabolism involving CYP4A and 20-HETE formation during their adulthood. PMID:26234927

  20. Arachidonic acid alters tomato HMG expression and fruit growth and induces 3-hydroxy-3-methylglutaryl coenzyme A reductase-independent lycopene accumulation

    SciTech Connect

    Rodriguez-Concepcion, M.; Gruissem, W.

    1999-01-01

    Regulation of isoprenoid end-product synthesis required for normal growth and development in plants is not well understood. To investigate the extent to which specific genes for the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) are involved in end-product regulation, the authors manipulated expression of the HMG1 and HMG2 genes in tomato (Lycopersicon esculentum) fruit using arachidonic acid (AA). In developing young fruit AA blocked fruit growth, inhibited HMG1, and activated HMG2 expression. These results are consistent with other reports indicating that HMG1 expression is closely correlated with growth processes requiring phytosterol production. In mature-green fruit AA strongly induced the expression of HMG2, PSY1 (the gene for phytoene synthase), and lycopene accumulation before the normal onset of carotenoid synthesis and ripening. The induction of lycopene synthesis was not blocked by inhibition of HMGR activity using mevinolin, suggesting that cytoplasmic HMGR is not required for carotenoid synthesis. Their results are consistent with the function of an alternative plastid isoprenoid pathway (the Rohmer pathway) that appears to direct the production of carotenoids during tomato fruit ripening.

  1. Exogenous Addition of Arachidonic Acid to the Culture Media Enhances the Functionality of Dendritic Cells for Their Possible Use in Cancer Immunotherapy

    PubMed Central

    Kumar, Jeetendra; Gurav, Rupali; Kale, Vaijayanti; Limaye, Lalita

    2014-01-01

    The development of dendritic cell based vaccines is a promising approach in cancer immunotherapy. For their successful use in the clinics, the propagation and functionality of DCs is crucial. We earlier established a two-step method for the large scale generation of DCs from umbilical cord blood derived MNCs/CD34+ cells. This work aims at improving their functionality based on the following observations: in vitro generated DCs can be less efficient in migration and other functional activities due to lower eicosanoid levels. The production of eicosanoids from Arachidonic Acid (AA) can be hampered due to suppression of the enzyme phospholipase A2 by IL-4, an essential cytokine required for the differentiation of DCs. We hypothesized that exogenous addition of AA to the culture media during DC generation may result in DCs with improved functionality. DCs were generated with and without AA. The two DC sets were compared by phenotypic analysis, morphology and functional assays like antigen uptake, MLR, CTL assay and in vitro and in vivo migration. Though there were no differences between the two types of DCs in terms of morphology, phenotype and antigen uptake, AA+ DCs exhibited an enhanced in vitro and in vivo migration, T cell stimulatory capacity, CTL activity and significantly higher transcript levels of COX-2. AA+ DCs also show a favorable Th1 cytokine profile than AA- DCs. Thus addition of AA to the culture media is skewing the DCs towards the secretion of more IL-12 and less of IL-10 along with the restoration of eicosanoids levels in a COX-2 mediated pathway thereby enhancing the functionality of these cells to be used as a potent cellular vaccine. Taken together, these findings will be helpful in the better contriving of DC based vaccines for cancer immunotherapy. PMID:25369453

  2. Glucagon-like peptide 1 receptor activation regulates cocaine actions and dopamine homeostasis in the lateral septum by decreasing arachidonic acid levels.

    PubMed

    Reddy, I A; Pino, J A; Weikop, P; Osses, N; Sørensen, G; Bering, T; Valle, C; Bluett, R J; Erreger, K; Wortwein, G; Reyes, J G; Graham, D; Stanwood, G D; Hackett, T A; Patel, S; Fink-Jensen, A; Torres, G E; Galli, A

    2016-01-01

    Agonism of the glucagon-like peptide 1 (GLP-1) receptor (GLP-1R) has been effective at treating aspects of addictive behavior for a number of abused substances, including cocaine. However, the molecular mechanisms and brain circuits underlying the therapeutic effects of GLP-1R signaling on cocaine actions remain elusive. Recent evidence has revealed that endogenous signaling at the GLP-1R within the forebrain lateral septum (LS) acts to reduce cocaine-induced locomotion and cocaine conditioned place preference, both considered dopamine (DA)-associated behaviors. DA terminals project from the ventral tegmental area to the LS and express the DA transporter (DAT). Cocaine acts by altering DA bioavailability by targeting the DAT. Therefore, GLP-1R signaling might exert effects on DAT to account for its regulation of cocaine-induced behaviors. We show that the GLP-1R is highly expressed within the LS. GLP-1, in LS slices, significantly enhances DAT surface expression and DAT function. Exenatide (Ex-4), a long-lasting synthetic analog of GLP-1 abolished cocaine-induced elevation of DA. Interestingly, acute administration of Ex-4 reduces septal expression of the retrograde messenger 2-arachidonylglycerol (2-AG), as well as a product of its presynaptic degradation, arachidonic acid (AA). Notably, AA reduces septal DAT function pointing to AA as a novel regulator of central DA homeostasis. We further show that AA oxidation product γ-ketoaldehyde (γ-KA) forms adducts with the DAT and reduces DAT plasma membrane expression and function. These results support a mechanism in which postsynaptic septal GLP-1R activation regulates 2-AG levels to alter presynaptic DA homeostasis and cocaine actions through AA. PMID:27187231

  3. Effect of docosahexaenoic acid and arachidonic acid on the expression of adipocyte determination and differentiation-dependent factor 1 in differentiating porcine adipocytes.

    PubMed

    Liu, B H; Kuo, C F; Wang, Y C; Ding, S T

    2005-07-01

    Adipocyte determination and differentiation-dependent factor 1 (ADD1) drives the expression of several lipogenic genes in mammals. Polyunsaturated fatty acids decrease ADD1 mRNA abundance in differentiating porcine adipocytes. The current study was designed to explore the mechanisms by which PUFA inhibit the expression of ADD1 in porcine adipocytes. Porcine preadipocytes were differentiated for 24 h with 0 or 100 microM of docosahexaenoic acid (DHA) and mixtures of different concentrations of antioxidants to investigate the effect of DHA and antioxidants on the ADD1 mRNA abundance. We found the relative mRNA abundance was decreased by the addition of 100 microM DHA to the medium for porcine differentiating adipocytes, and adding an antioxidant mixture to the medium prevented part of the decrease in ADD1 mRNA abundance. These data suggest that DHA decreased the steady-state transcription factor ADD1 mRNA through a mechanism related to fatty acid peroxidation. Indeed, adding 7.5 microM vitamin E (a natural antioxidant) also restored the concentrations of ADD1 and fatty acid synthase mRNA, which were decreased by DHA treatment; however, the DHA or the antioxidant treatment did not change the expression of antioxidation genes (superoxide dismutase 1 and glutathione peroxidase 1) in porcine stromal vascular cells. When supplemented with the eicosanoid synthesis pathway inhibitors, the inhibition of the expression of ADD1 by arachidonic acid was partially recovered. These results suggest that the mechanism by which PUFA decrease ADD1 mRNA is due to the metabolic product of eicosanoids and peroxidation of these PUFA.

  4. Analysis of cytochrome P450 metabolites of arachidonic acid by stable isotope probe labeling coupled with ultra high-performance liquid chromatography/mass spectrometry.

    PubMed

    Zhu, Quan-Fei; Hao, Yan-Hong; Liu, Ming-Zhou; Yue, Jiang; Ni, Jian; Yuan, Bi-Feng; Feng, Yu-Qi

    2015-09-01

    Cytochrome P450 metabolites of arachidonic acid (AA) belong to eicosanoids and are potent lipid mediators of inflammation. It is well-known that eicosanoids play an important role in numerous pathophysiological processes. Therefore, quantitative analysis of cytochrome P450 metabolites of AA, including hydroxyeicosatetraenoic acids (HETEs), epoxyeicosatreinoic acids (EETs), and dihydroxyeicosatrienoic acids (DHETs) can provide crucial information to uncover underlying mechanisms of cytochrome P450 metabolites of AA related diseases. Herein, we developed a highly sensitive method to identify and quantify HETEs, EETs, and DHETs in lipid extracts of biological samples based on stable isotope probe labeling coupled with ultra high-performance liquid chromatography/mass spectrometry. To this end, a pair of stable isotope probes, 2-dimethylaminoethylamine (DMED) and d4-2-dimethylaminoethylamine (d4-DMED), were utilized to facilely label eicosanoids. The heavy labeled eicosanoid standards were prepared and used as internal standards for quantification to minimize the matrix and ion suppression effects in mass spectrometry analysis. In addition, the detection sensitivities of DMED labeled eicosanoids improved by 3-104 folds in standard solution and 5-138 folds in serum matrix compared with unlabeled analytes. Moreover, a good separation of eicosanoids isomers was achieved upon DMED labeling. The established method provided substantial sensitivity (limit of quantification at sub-picogram), high specificity, and broad linear dynamics range (3 orders of magnitude). We further quantified cytochrome P450 metabolites of AA in rat liver, heart, brain tissues and human serum using the developed method. The results showed that 19 eicosanoids could be distinctly detected and the contents of 11-, 15-, 16-, 20-HETE, 5,6-EET, and 14,15-EET in type 2 diabetes mellitus patients and 5-, 11-, 12-, 15-, 16-, 20-HETE, 8,9-EET, and 5,6-DHET in myeloid leukemia patients had significant changes

  5. Dietary intakes of arachidonic acid and alpha-linolenic acid are associated with reduced risk of hip fracture in older adults.

    PubMed

    Farina, Emily K; Kiel, Douglas P; Roubenoff, Ronenn; Schaefer, Ernst J; Cupples, L Adrienne; Tucker, Katherine L

    2011-06-01

    PUFA are hypothesized to influence bone health, but longitudinal studies on hip fracture risk are lacking. We examined associations between intakes of PUFA and fish, and hip fracture risk among older adults (n = 904) in the Framingham Osteoporosis Study. Participants (mean age ~75 y at baseline) were followed for incident hip fracture from the time they completed the baseline exam (1988-1989) until December 31, 2005. HR and 95% CI were estimated for energy-adjusted dietary fatty acid exposure variables [(n-3) fatty acids: α-linolenic acid (ALA), EPA, DHA, EPA+DHA; (n-6) fatty acids: linoleic acid, arachidonic acid (AA); and the (n-6):(n-3) ratio] and fish intake categories, adjusting for potential confounders and covariates. Protective associations were observed between intakes of ALA (P-trend = 0.02) and hip fracture risk in a combined sample of women and men and between intakes of AA (P-trend = 0.05) and hip fracture risk in men only. Participants in the highest quartile of ALA intake had a 54% lower risk of hip fracture than those in the lowest quartile (Q4 vs. Q1: HR = 0.46; 95% CI = 0.26-0.83). Men in the highest quartile of AA intake had an 80% lower risk of hip fracture than those in the lowest quartile (Q4 vs. Q1: HR = 0.20; 95% CI = 0.04-0.96). No significant associations were observed among intakes of EPA, DHA, EPA+DHA, or fish. These findings suggest dietary ALA may reduce hip fracture risk in women and men and dietary AA may reduce hip fracture risk in men.

  6. The Effect of varying ratios of docosahexaenoic Acid and arachidonic acid in the prevention and reversal of biochemical essential fatty acid deficiency in a murine model

    PubMed Central

    Le, Hau D.; Fallon, Erica M.; Kalish, Brian T.; de Meijer, Vincent E.; Meisel, Jonathan A.; Gura, Kathleen M.; Nose, Vania; Pan, Amy H.; Bistrian, Bruce R.; Puder, Mark

    2012-01-01

    Objective Essential fatty acids (EFA) are necessary for growth, development, and biological function, and must be acquired through the diet. While linoleic acid (LA) and alpha-linolenic acid (ALA) have been considered the true EFAs, we previously demonstrated that docosahexaenoic acid (DHA) and arachidonic acid (AA) taken together as the sole source of dietary fatty acids can prevent biochemical essential fatty acid deficiency (EFAD). This study evaluates the effect of varying dietary ratios of DHA:AA in the prevention and reversal of biochemical EFAD in a murine model. Methods Using a murine model of EFAD, we provided mice with 2.1% of daily caloric intake in varying DHA:AA ratios (1:1, 5:1, 10:1, 20:1, 200:1, 100:0) for 19 days in association with a liquid high-carbohydrate fat-free diet to evaluate the effect on fatty acid profiles. In a second experiment, we evaluated the provision of varying DHA:AA ratios (20:1, 200:1, 100:0) on the reversal of biochemical EFAD. Results Mice provided with DHA and AA had no evidence of biochemical EFAD, regardless of the ratio (1:1, 5:1, 10:1, 20:1, 200:1, 100:0) administered. Biochemical EFAD was reversed with DHA:AA ratios of 20:1, 200:1, and 100:0 following 3 and 5 weeks of dietary provision, although the 20:1 ratio was most effective in the reversal and stabilization of the triene:tetraene ratio. Conclusion Provision of DHA and AA, at 2.1% of daily caloric intake in varying ratios can prevent biochemical evidence of EFAD and hepatic steatosis over the short-term, with a ratio of 20:1 DHA:AA most effectively reversing EFAD. PMID:23151438

  7. Identification and absolute configuration of dihydroxy-arachidonic acids formed by oxygenation of 5S-HETE by native and aspirin-acetylated COX-2.

    PubMed

    Mulugeta, Surafel; Suzuki, Takashi; Hernandez, Noemi Tejera; Griesser, Markus; Boeglin, William E; Schneider, Claus

    2010-03-01

    Biosynthesis of the prostaglandin endoperoxide by the cyclooxygenase (COX) enzymes is accompanied by formation of a small amount of 11R-hydroxyeicosatetraenoic acid (HETE), 15R-HETE, and 15S-HETE as by-products. Acetylation of COX-2 by aspirin abrogates prostaglandin synthesis and triggers formation of 15R-HETE as the sole product of oxygenation of arachidonic acid. Here, we investigated the formation of by-products of the transformation of 5S-HETE by native COX-2 and by aspirin-acetylated COX-2 using HPLC-ultraviolet, GC-MS, and LC-MS analysis. 5S,15S- dihydroxy (di)HETE, 5S,15R-diHETE, and 5S,11R-diHETE were identified as by-products of native COX-2, in addition to the previously described di-endoperoxide (5S,15S-dihydroxy-9S,11R,8S,12S-diperoxy-6E,13E-eicosadienoic acid) as the major oxygenation product. 5S,15R-diHETE was the only product formed by aspirin-acetylated COX-2. Both 5,15-diHETE and 5,11-diHETE were detected in CT26 mouse colon carcinoma cells as well as in lipopolysaccharide-activated RAW264.7 cells incubated with 5S-HETE, and their formation was attenuated in the presence of the COX-2 specific inhibitor, NS-398. Aspirin-treated CT26 cells gave 5,15-diHETE as the most prominent product formed from 5S-HETE. 5S,15S-diHETE has been described as a product of the cross-over of 5-lipoxygenase (5-LOX) and 15-LOX activities in elicited rat mononuclear cells and human leukocytes, and our studies implicate cross-over of the 5-LOX and COX-2 pathways as an additional biosynthetic route.

  8. Transcriptome analysis reveals unique C4-like photosynthesis and oil body formation in an arachidonic acid-rich microalga Myrmecia incisa Reisigl H4301

    PubMed Central

    2013-01-01

    Background Arachidonic acid (ArA) is important for human health because it is one of the major components of mammalian brain membrane phospholipids. The interest in ArA inspired the search for a new sustainable source, and the green microalga Myrmecia incisa Reisigl H4301 has been found a potential ArA-producer due to a high content of intracellular ArA. To gain more molecular information about metabolism pathways, including the biosynthesis of ArA in the non-model microalga, a transcriptomic analysis was performed. Results The 454 pyrosequencing generated 371,740 high-quality reads, which were assembled into 51,908 unique sequences consisting of 22,749 contigs and 29,159 singletons. A total of 11,873 unique sequences were annotated through BLAST analysis, and 3,733 were assigned to Gene Ontology (GO) categories. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis uncovered a C4-like photosynthesis pathway in M. incisa. The biosynthesis pathways of lipid particularly those of ArA and triacylglycerol (TAG) were analyzed in detail, and TAG was proposed to be accumulated in oil bodies in the cytosol with the help of caleosin or oil globule-associated proteins. In addition, the carotenoid biosynthesis pathways are discussed. Conclusion This transcriptomic analysis of M. incisa enabled a global understanding of mechanisms involved in photosynthesis, de novo biosynthesis of ArA, metabolism of carotenoids, and accumulation of TAG in M. incisa. These findings provided a molecular basis for the research and possibly economic exploitation of this ArA-rich microalga. PMID:23759028

  9. Group X Secreted Phospholipase A2 Proenzyme Is Matured by a Furin-like Proprotein Convertase and Releases Arachidonic Acid inside of Human HEK293 Cells*

    PubMed Central

    Jemel, Ikram; Ii, Hiromi; Oslund, Rob C.; Payré, Christine; Dabert-Gay, Anne-Sophie; Douguet, Dominique; Chargui, Khaoula; Scarzello, Sabine; Gelb, Michael H.; Lambeau, Gérard

    2011-01-01

    Among mammalian secreted phospholipases A2 (sPLA2s), group X sPLA2 has the most potent hydrolyzing activity toward phosphatidylcholine and is involved in arachidonic acid (AA) release. Group X sPLA2 is produced as a proenzyme and contains a short propeptide of 11 amino acids ending with a dibasic motif, suggesting cleavage by proprotein convertases. Although the removal of this propeptide is clearly required for enzymatic activity, the cellular location and the protease(s) involved in proenzyme conversion are unknown. Here we have analyzed the maturation of group X sPLA2 in HEK293 cells, which have been extensively used to analyze sPLA2-induced AA release. Using recombinant mouse (PromGX) and human (ProhGX) proenzymes; HEK293 cells transfected with cDNAs coding for full-length ProhGX, PromGX, and propeptide mutants; and various permeable and non-permeable sPLA2 inhibitors and protease inhibitors, we demonstrate that group X sPLA2 is mainly converted intracellularly and releases AA before externalization from the cell. Most strikingly, the exogenous proenzyme does not elicit AA release, whereas the transfected proenzyme does elicit AA release in a way insensitive to non-permeable sPLA2 inhibitors. In transfected cells, a permeable proprotein convertase inhibitor, but not a non-permeable one, prevents group X sPLA2 maturation and partially blocks AA release. Mutations at the dibasic motif of the propeptide indicate that the last basic residue is required and sufficient for efficient maturation and AA release. All together, these results argue for the intracellular maturation of group X proenzyme in HEK293 cells by a furin-like proprotein convertase, leading to intracellular release of AA during secretion. PMID:21878635

  10. Glucagon-like peptide 1 receptor activation regulates cocaine actions and dopamine homeostasis in the lateral septum by decreasing arachidonic acid levels

    PubMed Central

    Reddy, I A; Pino, J A; Weikop, P; Osses, N; Sørensen, G; Bering, T; Valle, C; Bluett, R J; Erreger, K; Wortwein, G; Reyes, J G; Graham, D; Stanwood, G D; Hackett, T A; Patel, S; Fink-Jensen, A; Torres, G E; Galli, A

    2016-01-01

    Agonism of the glucagon-like peptide 1 (GLP-1) receptor (GLP-1R) has been effective at treating aspects of addictive behavior for a number of abused substances, including cocaine. However, the molecular mechanisms and brain circuits underlying the therapeutic effects of GLP-1R signaling on cocaine actions remain elusive. Recent evidence has revealed that endogenous signaling at the GLP-1R within the forebrain lateral septum (LS) acts to reduce cocaine-induced locomotion and cocaine conditioned place preference, both considered dopamine (DA)-associated behaviors. DA terminals project from the ventral tegmental area to the LS and express the DA transporter (DAT). Cocaine acts by altering DA bioavailability by targeting the DAT. Therefore, GLP-1R signaling might exert effects on DAT to account for its regulation of cocaine-induced behaviors. We show that the GLP-1R is highly expressed within the LS. GLP-1, in LS slices, significantly enhances DAT surface expression and DAT function. Exenatide (Ex-4), a long-lasting synthetic analog of GLP-1 abolished cocaine-induced elevation of DA. Interestingly, acute administration of Ex-4 reduces septal expression of the retrograde messenger 2-arachidonylglycerol (2-AG), as well as a product of its presynaptic degradation, arachidonic acid (AA). Notably, AA reduces septal DAT function pointing to AA as a novel regulator of central DA homeostasis. We further show that AA oxidation product γ-ketoaldehyde (γ-KA) forms adducts with the DAT and reduces DAT plasma membrane expression and function. These results support a mechanism in which postsynaptic septal GLP-1R activation regulates 2-AG levels to alter presynaptic DA homeostasis and cocaine actions through AA. PMID:27187231

  11. Sex Differences in the Association between the Eicosapentaenoic Acid/Arachidonic Acid Ratio and the Visceral Fat Area among Patients with Type 2 Diabetes.

    PubMed

    Nakanishi, Shuhei; Nagano, Chihiro; Miyahara, Mitsue; Sawano, Fumio

    2016-01-01

    Objective To examine the serum levels of eicosapentaenoic acid (EPA) and the ratios of docosahexaenoic acid (DHA), and the EPA/arachidonic acid (AA) and DHA/AA and to clarify their association with the areas of subcutaneous and visceral fat separately by sex among patients with type 2 diabetes. Methods The study participants included 118 men and 96 women who were hospitalized to receive treatment for type 2 diabetes. We examined the serum levels of EPA and DHA and the ratios of EPA/AA and DHA/AA, and analyzed their association with the total fat area (TFA), subcutaneous fat area (SFA), and visceral fat area (VFA), as measured by computed tomography. Results The mean age of the study participants was 62.6±13.6 years. The mean HbA1c level was 9.37±2.27%. Among men, a multivariate regression analysis adjusted for age and BMI, revealed a significant negative association between VFA and the EPA/AA ratio. When the multivariate regression analysis was adjusted for age, BMI, and HbA1c level, VFA was still found to be significantly negatively associated with the EPA/AA ratio. Although a crude analysis revealed a significant negative association between SFA and the EPA/AA ratio in women, no association was observed in multivariate regression analyses. Conclusion These results suggest the possibility that EPA inhibits the accumulation of visceral fat in men. Furthermore, there appear to be marked differences in the relationships between EPA and DHA and visceral fat accumulation. PMID:27181531

  12. Understanding the Mechanism of the Hydrogen Abstraction from Arachidonic Acid Catalyzed by the Human Enzyme 15-Lipoxygenase-2. A Quantum Mechanics/Molecular Mechanics Free Energy Simulation.

    PubMed

    Suardíaz, Reynier; Jambrina, Pablo G; Masgrau, Laura; González-Lafont, Àngels; Rosta, Edina; Lluch, José M

    2016-04-12

    Lipoxygenases (LOXs) are a family of enzymes involved in the biosynthesis of several lipid mediators. In the case of human 15-LOX, the 15-LOX-1 and 15-LOX-2 isoforms show slightly different reaction regiospecificity and substrate specificity, indicating that substrate binding and recognition may be different, a fact that could be related to their different biological role. Here, we have used long molecular dynamics simulations, QM(DFT)/MM potential energy and free energy calculations (using the newly developed DHAM method), to investigate the binding mode of the arachidonic acid (AA) substrate into 15-LOX-2 and the rate-limiting hydrogen-abstraction reaction 15-LOX-2 catalyzes. Our results strongly indicate that hydrogen abstraction from C13 in 15-LOX-2 is only consistent with the "tail-first" orientation of AA, with its carboxylate group interacting with Arg429, and that only the pro-S H13 hydrogen will be abstracted (being the pro-R H13 and H10 too far from the acceptor oxygen atom). At the B3LYP/6-31G(d) level the potential and free energy barriers for the pro-S H13 abstraction of AA by 15-LOX-2 are 18.0 and 18.6 kcal/mol, respectively. To analyze the kinetics of the hydrogen abstraction process, we determined a Markov model corresponding to the unbiased simulations along the state-discretized reaction coordinate. The calculated rates based on the second largest eigenvalue of the Markov matrices agree well with experimental measurements, and also provide the means to directly determine the pre-exponential factor for the reaction by comparing with the free energy barrier height. Our calculated pre-exponential factor is close to the value of kBT/h. On the other hand, our results suggest that the spin inversion of the complete system (including the O2 molecule) that is required to happen at some point along the full process to lead to the final hydroperoxide product, is likely to take place during the hydrogen transfer, which is a proton coupled electron transfer

  13. Role of arachidonic acid and protein kinase C during maturation-inducing hormone-dependent meiotic resumption and ovulation in ovarian follicles of Atlantic croaker

    USGS Publications Warehouse

    Patino, R.; Yoshizaki, G.; Bolamba, D.; Thomas, P.

    2003-01-01

    The roles of arachidonic acid (AA) and protein kinase C (PKC) during in vitro maturation-inducing hormone (MIH)-dependent meiotic resumption (maturation) and ovulation were studied in ovarian follicles of Atlantic croaker (Micropogonias undulatus). The requirement for cyclooxygenase (COX) metabolites of AA was examined using a nonspecific COX inhibitor, indomethacin (IM), as well as two COX products, prostaglandin (PG) F2?? and PGE2, whereas the role of lipoxygenase (LOX) was investigated using a specific LOX inhibitor, nordihydroguaiaretic acid (NDGA). The involvement of PKC was examined using phorbol 12-myristate 13-acetate (PMA), a PKC activator, as well as GF109203X (GF), a specific inhibitor of PKC and 1-(5-isoquin- olinesulfonyl)-2-methylpiperazine (H7), nonspecific inhibitor of protein kinases. Genomic mechanisms were examined with the transcription-inhibitor actinomycin D (ActD) and the functionality of heterologous (oocyte-granulosa) gap junctions (GJ) with a dye transfer assay. The AA (100 ??M) and PGF2?? (5 ??M) did not induce maturation, and NDGA (10 ??M) did not affect MIH-dependent maturation. However, IM (100 ??M) partially inhibited MIH-dependent maturation. Conversely, AA and both PGs induced, and IM and NDGA inhibited, MIH-dependent ovulation in matured follicles. The PMA (1 ??g/ml) did not induce maturation but caused ovulation in matured follicles, whereas PKC inhibitors (GF, 5 ??M; H7, 50??M) did not affect MIH-dependent maturation but inhibited MIH- and PMA-dependent ovulation. The PMA-dependent ovulation was inhibited by IM but not by NDGA. In addition, ActD (5 ??M) blocked MIH-dependent, but not PMA-dependent, ovulation, and PGF2?? restored MIH-dependent ovulation in ActD-blocked follicles. The AA and PGs did not induce, and GF did not inhibit, MIH-dependent heterologous GJ uncoupling. In conclusion, AA and PKC mediate MIH-dependent ovulation but not meiotic resumption or heterologous GJ uncoupling in croaker follicles, but a permissive role

  14. Understanding the Mechanism of the Hydrogen Abstraction from Arachidonic Acid Catalyzed by the Human Enzyme 15-Lipoxygenase-2. A Quantum Mechanics/Molecular Mechanics Free Energy Simulation.

    PubMed

    Suardíaz, Reynier; Jambrina, Pablo G; Masgrau, Laura; González-Lafont, Àngels; Rosta, Edina; Lluch, José M

    2016-04-12

    Lipoxygenases (LOXs) are a family of enzymes involved in the biosynthesis of several lipid mediators. In the case of human 15-LOX, the 15-LOX-1 and 15-LOX-2 isoforms show slightly different reaction regiospecificity and substrate specificity, indicating that substrate binding and recognition may be different, a fact that could be related to their different biological role. Here, we have used long molecular dynamics simulations, QM(DFT)/MM potential energy and free energy calculations (using the newly developed DHAM method), to investigate the binding mode of the arachidonic acid (AA) substrate into 15-LOX-2 and the rate-limiting hydrogen-abstraction reaction 15-LOX-2 catalyzes. Our results strongly indicate that hydrogen abstraction from C13 in 15-LOX-2 is only consistent with the "tail-first" orientation of AA, with its carboxylate group interacting with Arg429, and that only the pro-S H13 hydrogen will be abstracted (being the pro-R H13 and H10 too far from the acceptor oxygen atom). At the B3LYP/6-31G(d) level the potential and free energy barriers for the pro-S H13 abstraction of AA by 15-LOX-2 are 18.0 and 18.6 kcal/mol, respectively. To analyze the kinetics of the hydrogen abstraction process, we determined a Markov model corresponding to the unbiased simulations along the state-discretized reaction coordinate. The calculated rates based on the second largest eigenvalue of the Markov matrices agree well with experimental measurements, and also provide the means to directly determine the pre-exponential factor for the reaction by comparing with the free energy barrier height. Our calculated pre-exponential factor is close to the value of kBT/h. On the other hand, our results suggest that the spin inversion of the complete system (including the O2 molecule) that is required to happen at some point along the full process to lead to the final hydroperoxide product, is likely to take place during the hydrogen transfer, which is a proton coupled electron transfer

  15. Oxygenation by COX-2 (cyclo-oxygenase-2) of 3-HETE (3-hydroxyeicosatetraenoic acid), a fungal mimetic of arachidonic acid, produces a cascade of novel bioactive 3-hydroxyeicosanoids

    PubMed Central

    2005-01-01

    Cyclo-oxygenases-1/2 (COX-1/2) catalyse the oxygenation of AA (arachidonic acid) and related polyunsaturated fatty acids to endoperoxide precursors of prostanoids. COX-1 is referred to as a constitutive enzyme involved in haemostasis, whereas COX-2 is an inducible enzyme expressed in inflammatory diseases and cancer. The fungus Dipodascopsis uninucleata has been shown by us to convert exogenous AA into 3(R)-HETE [3(R)-hydroxy-5Z,8Z,11Z,14Z-eicosatetraenoic acid]. 3R-HETE is stereochemically identical with AA, except that a hydroxy group is attached at its C-3 position. Molecular modelling studies with 3-HETE and COX-1/2 revealed a similar enzyme–substrate structure as reported for AA and COX-1/2. Here, we report that 3-HETE is an appropriate substrate for COX-1 and -2, albeit with a lower activity of oxygenation than AA. Oxygenation of 3-HETE by COX-2 produced a novel cascade of 3-hydroxyeicosanoids, as identified with EI (electron impact)–GC–MS, LC–MS–ES (electrospray) and LC–MS–API (atmospheric pressure ionization) methods. Evidence for in vitro production of 3-hydroxy-PGE2 (3-hydroxy-prostaglandin E2) was obtained upon infection of HeLa cells with Candida albicans at an MOI (multiplicity of infection) of 100. Analogous to interaction of AA and aspirin-treated COX-2, 3-HETE was transformed by acetylated COX-2 to 3,15-di-HETE (3,15-dihydroxy-HETE), whereby C-15 showed the (R)-stereochemistry. 3-Hydroxy-PGs are potent biologically active compounds. Thus 3-hydroxy-PGE2 induced interleukin-6 gene expression via the EP3 receptor (PGE2 receptor 3) in A549 cells, and raised cAMP levels via the EP4 receptor in Jurkat cells. Moreover, 3R,15S-di-HETE triggered the opening of the K+ channel in HTM (human trabecular meshwork) cells, as measured by the patch–clamp technique. Since many fatty acid disorders are associated with an ‘escape’ of 3-hydroxy fatty acids from the β-oxidation cycle, the production of 3-hydroxyeicosanoids may be critical in

  16. The in vitro effect of aspirin on increased whole blood platelet aggregation in oral contraceptive users.

    PubMed

    Norris, L A; Bonnar, J

    1994-05-01

    The effects of triphasic oral contraceptives on whole blood platelet aggregation in 36 Italian women are reported here. Aspirin's effects on platelet aggregation were also studied. 18 women took a triphasic oral contraceptive; 10 women took Trinordiol, while 8 took Trinovum for at least 90 days. The remaining 18 women took nothing and served as controls. The study was aligned with each woman's birth control pill cycle. Blood was taken daily on days 15-21 of their cycle. Either saline solution or acetylsalicylic acid was added to the blood samples and compared. All data was statistically analyzed using unpaired student's t-test. Effects of 3 aggregating agents, ADP, PAF, and EDTA, on platelet aggregation were studied. Arachidonic acid and adrenalin bitartrate were also studied in this manner. An increase in platelet aggregation was observed in women taking oral contraceptives. No difference was found between patients taking Trinordiol and those taking Trinovum. The results of this study indicate an increase in whole blood platelet sensitivity to collagen, adrenalin, and arachidonic acid when using oral contraceptives. Aspirin, at low doses, may have a role in preventing early thrombus formation in women taking oral contraceptives. PMID:8042198

  17. Cyp2c44 epoxygenase is essential for preventing the renal sodium absorption during increasing dietary potassium intake.

    PubMed

    Sun, Peng; Antoun, Joseph; Lin, Dao-Hong; Yue, Peng; Gotlinger, Katherine H; Capdevila, Jorge; Wang, Wen-Hui

    2012-02-01

    The aim of this study is to test whether the Cyp2c44 epoxygenase-dependent metabolism of arachidonic acid prevents the hypertensive effect of a high K (HK) intake by inhibiting the epithelial sodium channel (ENaC) activity. A HK intake elevated Cyp2c44 mRNA expression and 11,12-epoxyeicosatrienoic acid levels in the cortical collecting duct in Cyp2c44(+/+) mice (wild-type [wt]). However, an HK intake failed to increase 11,12-epoxyeicosatrienoic acid formation in the cortical collecting ducts of Cyp2c44(-/-) mice. Moreover, increasing K intake enhanced arachidonic acid-induced inhibition of ENaC in the wt but not in Cyp2c44(-/-) mice. In contrast, 11,12-epoxyeicosatrienoic acid, a Cyp2c44 metabolite, inhibited ENaC in the wt and Cyp2c44(-/-) mice. The notion that Cyp2c44 is the epoxygenase responsible for mediating the inhibitory effects of arachidonic acid on ENaC is further suggested by the observation that inhibiting Cyp-epoxygenase increased the whole-cell Na currents in principal cells of wt but not in Cyp2c44(-/-) mice. Feeding mice with an HK diet raised the systemic blood pressures of Cyp2c44(-/-) mice but was without an effect on wt mice. Moreover, application of amiloride abolished the HK-induced hypertension in Cyp2c44(-/-) mice. The HK-induced hypertension of Cyp2c44(-/-) mice was accompanied by decreasing 24-hour urinary Na excretion and increasing the plasma Na concentration, and the effects were absent in wt mice. In contrast, disruption of the Cyp2c44 gene did not alter K excretion. We conclude that Cyp2c44 epoxygenase mediates the inhibitory effect of arachidonic acid on ENaC and that Cyp2c44 functions as an HK-inducible antihypertensive enzyme responsible for inhibiting ENaC activity and Na absorption in the aldosterone-sensitive distal nephron.

  18. Titanium Dioxide Nanoparticles Increase Superoxide Anion Production by Acting on NADPH Oxidase

    PubMed Central

    Trepout, Sylvain; Wien, Frank; Marco, Sergio

    2015-01-01

    Titanium dioxide (TiO2) anatase nanoparticles (NPs) are metal oxide NPs commercialized for several uses of everyday life. However their toxicity has been poorly investigated. Cellular internalization of NPs has been shown to activate macrophages and neutrophils that contribute to superoxide anion production by the NADPH oxidase complex. Transmission electron micrososcopy images showed that the membrane fractions were close to the NPs while fluorescence indicated an interaction between NPs and cytosolic proteins. Using a cell-free system, we have investigated the influence of TiO2 NPs on the behavior of the NADPH oxidase. In the absence of the classical activator molecules of the enzyme (arachidonic acid) but in the presence of TiO2 NPs, no production of superoxide ions could be detected indicating that TiO2 NPs were unable to activate by themselves the complex. However once the NADPH oxidase was activated (i.e., by arachidonic acid), the rate of superoxide anion production went up to 140% of its value without NPs, this effect being dependent on their concentration. In the presence of TiO2 nanoparticles, the NADPH oxidase produces more superoxide ions, hence induces higher oxidative stress. This hyper-activation and the subsequent increase in ROS production by TiO2 NPs could participate to the oxidative stress development. PMID:26714308

  19. Titanium Dioxide Nanoparticles Increase Superoxide Anion Production by Acting on NADPH Oxidase.

    PubMed

    Masoud, Rawand; Bizouarn, Tania; Trepout, Sylvain; Wien, Frank; Baciou, Laura; Marco, Sergio; Houée Levin, Chantal

    2015-01-01

    Titanium dioxide (TiO2) anatase nanoparticles (NPs) are metal oxide NPs commercialized for several uses of everyday life. However their toxicity has been poorly investigated. Cellular internalization of NPs has been shown to activate macrophages and neutrophils that contribute to superoxide anion production by the NADPH oxidase complex. Transmission electron micrososcopy images showed that the membrane fractions were close to the NPs while fluorescence indicated an interaction between NPs and cytosolic proteins. Using a cell-free system, we have investigated the influence of TiO2 NPs on the behavior of the NADPH oxidase. In the absence of the classical activator molecules of the enzyme (arachidonic acid) but in the presence of TiO2 NPs, no production of superoxide ions could be detected indicating that TiO2 NPs were unable to activate by themselves the complex. However once the NADPH oxidase was activated (i.e., by arachidonic acid), the rate of superoxide anion production went up to 140% of its value without NPs, this effect being dependent on their concentration. In the presence of TiO2 nanoparticles, the NADPH oxidase produces more superoxide ions, hence induces higher oxidative stress. This hyper-activation and the subsequent increase in ROS production by TiO2 NPs could participate to the oxidative stress development. PMID:26714308

  20. Increased peripheral vascular disease risk progressively constrains perfusion adaptability in the skeletal muscle microcirculation.

    PubMed

    Frisbee, Jefferson C; Butcher, Joshua T; Frisbee, Stephanie J; Olfert, I Mark; Chantler, Paul D; Tabone, Lawrence E; d'Audiffret, Alexandre C; Shrader, Carl D; Goodwill, Adam G; Stapleton, Phoebe A; Brooks, Steven D; Brock, Robert W; Lombard, Julian H

    2016-02-15

    To determine the impact of progressive elevations in peripheral vascular disease (PVD) risk on microvascular function, we utilized eight rat models spanning "healthy" to "high PVD risk" and used a multiscale approach to interrogate microvascular function and outcomes: healthy: Sprague-Dawley rats (SDR) and lean Zucker rats (LZR); mild risk: SDR on high-salt diet (HSD) and SDR on high-fructose diet (HFD); moderate risk: reduced renal mass-hypertensive rats (RRM) and spontaneously hypertensive rats (SHR); high risk: obese Zucker rats (OZR) and Dahl salt-sensitive rats (DSS). Vascular reactivity and biochemical analyses demonstrated that even mild elevations in PVD risk severely attenuated nitric oxide (NO) bioavailability and caused progressive shifts in arachidonic acid metabolism, increasing thromboxane A2 levels. With the introduction of hypertension, arteriolar myogenic activation and adrenergic constriction were increased. However, while functional hyperemia and fatigue resistance of in situ skeletal muscle were not impacted with mild or moderate PVD risk, blood oxygen handling suggested an increasingly heterogeneous perfusion within resting and contracting skeletal muscle. Analysis of in situ networks demonstrated an increasingly stable and heterogeneous distribution of perfusion at arteriolar bifurcations with elevated PVD risk, a phenomenon that was manifested first in the distal microcirculation and evolved proximally with increasing risk. The increased perfusion distribution heterogeneity and loss of flexibility throughout the microvascular network, the result of the combined effects on NO bioavailability, arachidonic acid metabolism, myogenic activation, and adrenergic constriction, may represent the most accurate predictor of the skeletal muscle microvasculopathy and poor health outcomes associated with chronic elevations in PVD risk. PMID:26702145

  1. Resistance of essential fatty acid-deficient rats to endotoxin-induced increases in vascular permeability

    SciTech Connect

    Li, E.J.; Cook, J.A.; Spicer, K.M.; Wise, W.C.; Rokach, J.; Halushka, P.V. )

    1990-06-01

    Resistance to endotoxin in essential fatty acid-deficient (EFAD) rats is associated with reduced synthesis of certain arachidonic acid metabolites. It was hypothesized that EFAD rats would manifest decreased vascular permeability changes during endotoxemia as a consequence of reduced arachidonic acid metabolism. To test this hypothesis, changes in hematocrit (HCT) and mesenteric localization rate of technetium-labeled human serum albumin (99mTc-HSA) and red blood cells (99mTc-RBC) were assessed in EFAD and normal rats using gamma-camera imaging. Thirty minutes after Salmonella enteritidis endotoxin, EFAD rats exhibited less hemoconcentration as determined by % HCT than normal rats. Endotoxin caused a less severe change in permeability index in the splanchnic region in EFAD rats than in normal rats (1.2 +/- 0.6 x 10(-3)min-1 vs. 4.9 +/- 1.7 x 10(-3)min-1 respectively, P less than 0.05). In contrast to 99mTc-HSA, mesenteric localization of 99mTc-RBC was not changed by endotoxin in control or EFAD rats. Supplementation with ethyl-arachidonic acid did not enhance susceptibility of EFAD rats to endotoxin-induced splanchnic permeability to 99mTc-HSA. Leukotrienes have been implicated as mediators of increased vascular permeability in endotoxin shock. Since LTC3 formation has been reported to be increased in EFA deficiency, we hypothesized that LTC3 may be less potent than LTC4. Thus the effect of LTC3 on mean arterial pressure and permeability was compared to LTC4 in normal rats. LTC3-induced increases in peak mean arterial pressure were less than LTC4 at 10 micrograms/kg (39 +/- 5 mm Hg vs. 58 +/- 4 mm Hg respectively, P less than 0.05) and at 20 micrograms/kg (56 +/- 4 mm Hg vs. 75 +/- 2 mm Hg respectively, P less than 0.05). LY171883 (30 mg/kg), an LTD4/E4 receptor antagonist, attenuated the pressor effect of LTC4, LTD4, and LTC3.

  2. Mas receptor overexpression increased Ang-(1-7) relaxation response in renovascular hypertensive rat carotid.

    PubMed

    Olivon, V C; Aires, R D; Santiago, L B; Ramalho, L Z N; Cortes, S F; Lemos, V S

    2015-09-01

    Renin-angiotensin system (RAS) is an important factor in the pathophysiology of hypertension. Mas receptor, Angiotensin-(1-7) [Ang-(1-7)]-activated receptor, is an important RAS component and exerts protective effects in the vasculature. Ang-(1-7) vascular effects and Mas receptor expression in carotid from renovascular hypertensive (2K-1C) rats is not clear. In the present study we investigated Mas receptor vasodilator response activated by Ang-(1-7) in the carotid rings from sham and 2K-1C rats. Changes in isometric tension were recorded on organ chamber. Mas receptors expression was investigated in carotid by Western blot. Nitric oxide production was evaluated by 2,3-diaminonaphthalene (DAN) and eNOS expression and activity by immunofluoresce and western blot, respectively. Ang-(1-7) induced concentration-dependent vasodilator effect in carotid rings from sham and 2K-1C, which the hypertension increased vasodilatation response. In the 2K-1C carotid rings, A-779 (Mas receptor antagonist) reduced but not abolish the vasodilator effect of Ang-(1-7). Corroborating, Mas receptor protein expression was significantly increased in the 2K-1C rats. L-NAME and ibuprofen decreased Ang-(1-7) vasodilator response and L-NAME plus ibuprofen practically abolish the remaining vasodilatation response. Nitric oxide production is increased due increased of eNOS expression and pSer(1177) activity. Our results demonstrated that renovascular hypertension increased Mas receptors expression and nitric oxide production in the rats carotid which, consequently increased Ang-(1-7)-vasorelaxant response. PMID:26256416

  3. Effect of dietary supplementation with increasing doses of docosahexaenoic acid on neutrophil lipid composition and leukotriene production in human healthy volunteers.

    PubMed

    Stanke-Labesque, Françoise; Molière, Patrick; Bessard, Jeanine; Laville, Martine; Véricel, Evelyne; Lagarde, Michel

    2008-10-01

    n-3 PUFA supplementation helps in the prevention or treatment of inflammatory diseases and CVD. However, many supplementations reported sofar are either a combination of n-3 PUFA or used large daily amounts of n-3 PUFA dosages. The present study investigated the influence of increasing dose intake of DHA on the fatty acid composition of phospholipids in neutrophils and on their capability to produce leukotrienes(LT) B4 and B5 in vitro. Twelve healthy volunteers were supplemented with increasing daily doses of DHA (200, 400, 800 and 1600 mg, each dose in TAG containing DHA as the only PUFA and for a 2-week period). At the end of each supplementation period, neutrophil fatty acid composition,and LTB4 and LTB5 production were determined by GC and liquid chromatography-tandem MS, respectively. The DHA/arachidonic acid ratio increased in a dose-dependent manner with respect to the increasing doses of DHA supplementation and was significantly different from baseline after supplementation with either 400, 800 or 1600 mg DHA. The LTB5/LTB4 ratio was significantly increased compared to baseline after supplementation with 800 and 1600 mg DHA. LTB5/LTB4 and DHA/arachidonic acid ratios were correlated (r 0.531, P<0.0001). The present data suggest that both changes in neutrophil lipid composition and LT production occurred with daily supplementation with 800 and 1600 mg DHA. The clinical benefits associated with these doses of DHA in inflammatory diseases remain to be investigated.

  4. Up-Regulated Expression of AOS-LOXa and Increased Eicosanoid Synthesis in Response to Coral Wounding

    PubMed Central

    Lõhelaid, Helike; Teder, Tarvi; Tõldsepp, Kadri; Ekins, Merrick; Samel, Nigulas

    2014-01-01

    In octocorals, a catalase–like allene oxide synthase (AOS) and an 8R-lipoxygenase (LOX) gene are fused together encoding for a single AOS-LOX fusion protein. Although the AOS-LOX pathway is central to the arachidonate metabolism in corals, its biological function in coral homeostasis is unclear. Using an acute incision wound model in the soft coral Capnella imbricata, we here test whether LOX pathway, similar to its role in plants, can contribute to the coral damage response and regeneration. Analysis of metabolites formed from exogenous arachidonate before and after fixed time intervals following wounding indicated a significant increase in AOS-LOX activity in response to mechanical injury. Two AOS-LOX isoforms, AOS-LOXa and AOS-LOXb, were cloned and expressed in bacterial expression system as active fusion proteins. Transcription levels of corresponding genes were measured in normal and stressed coral by qPCR. After wounding, AOS-LOXa was markedly up-regulated in both, the tissue adjacent to the incision and distal parts of a coral colony (with the maximum reached at 1 h and 6 h post wounding, respectively), while AOS-LOXb was stable. According to mRNA expression analysis, combined with detection of eicosanoid product formation for the first time, the AOS-LOX was identified as an early stress response gene which is induced by mechanical injury in coral. PMID:24551239

  5. Jujuboside B Reduces Vascular Tension by Increasing Ca2+ Influx and Activating Endothelial Nitric Oxide Synthase

    PubMed Central

    Zhao, Yixiu; Zhang, Xin; Li, Jiannan; Bian, Yu; Sheng, Miaomiao; Liu, Bin; Fu, Zidong; Zhang, Yan; Yang, Baofeng

    2016-01-01

    Jujuboside B has been reported to have protective effect on many cardiovascular diseases. However, the effects of Jujuboside B on vascular tension and endothelial function are unknown. The present study investigated the effects of Jujuboside B on reducing vascular tension, protecting endothelial function and the potential mechanisms. The tension of isolated rat thoracic aorta ring was measured by Wire myograph system. The concentration of nitric oxide (NO) and the activity of endothelial nitric oxide synthase (eNOS) in human aortic endothelial cells (HAECs) were determined by Griess reagent method and enzyme-linked immune sorbent assay. The protein levels of eNOS and p-eNOS at Serine-1177 were determined by western blot analysis. Intracellular Ca2+ concentration in HAECs was measured by laser confocal imaging microscopy. Results showed that Jujuboside B reduced the tension of rat thoracic aorta rings with intact endothelium in a dose-dependent manner. L-NAME, KN93, EGTA, SKF96365, iberiotoxin and glibenclamide significantly attenuated Jujuboside B-induced vasodilation in endothelium-intact tissues. In contrast, indometacin and 4-DAMP had no such effects. Jujuboside B also promoted NO generation and increased eNOS activity, which were attenuated by L-NAME, EGTA and SKF96365. Moreover, Jujuboside B increased intracellular Ca2+ concentration dose-dependently, which was inhibited by EGTA and SKF96365. Besides, Jujuboside B induced a rapid Ca2+ influx instantaneously after depleting intracellular Ca2+ store, which was significantly inhibited by SKF96365. In conclusion, this study preliminarily confirmed that Jujuboside B reduced vascular tension endothelium-dependently. The underlying mechanisms involved that Jujuboside B increased extracellular Ca2+ influx through endothelial transient receptor potential cation (TRPC) channels, phosphorylated eNOS and promoted NO generation in vascular endothelial cells. In addition, Jujuboside B-induced vasodilation involved

  6. Jujuboside B Reduces Vascular Tension by Increasing Ca2+ Influx and Activating Endothelial Nitric Oxide Synthase.

    PubMed

    Zhao, Yixiu; Zhang, Xin; Li, Jiannan; Bian, Yu; Sheng, Miaomiao; Liu, Bin; Fu, Zidong; Zhang, Yan; Yang, Baofeng

    2016-01-01

    Jujuboside B has been reported to have protective effect on many cardiovascular diseases. However, the effects of Jujuboside B on vascular tension and endothelial function are unknown. The present study investigated the effects of Jujuboside B on reducing vascular tension, protecting endothelial function and the potential mechanisms. The tension of isolated rat thoracic aorta ring was measured by Wire myograph system. The concentration of nitric oxide (NO) and the activity of endothelial nitric oxide synthase (eNOS) in human aortic endothelial cells (HAECs) were determined by Griess reagent method and enzyme-linked immune sorbent assay. The protein levels of eNOS and p-eNOS at Serine-1177 were determined by western blot analysis. Intracellular Ca2+ concentration in HAECs was measured by laser confocal imaging microscopy. Results showed that Jujuboside B reduced the tension of rat thoracic aorta rings with intact endothelium in a dose-dependent manner. L-NAME, KN93, EGTA, SKF96365, iberiotoxin and glibenclamide significantly attenuated Jujuboside B-induced vasodilation in endothelium-intact tissues. In contrast, indometacin and 4-DAMP had no such effects. Jujuboside B also promoted NO generation and increased eNOS activity, which were attenuated by L-NAME, EGTA and SKF96365. Moreover, Jujuboside B increased intracellular Ca2+ concentration dose-dependently, which was inhibited by EGTA and SKF96365. Besides, Jujuboside B induced a rapid Ca2+ influx instantaneously after depleting intracellular Ca2+ store, which was significantly inhibited by SKF96365. In conclusion, this study preliminarily confirmed that Jujuboside B reduced vascular tension endothelium-dependently. The underlying mechanisms involved that Jujuboside B increased extracellular Ca2+ influx through endothelial transient receptor potential cation (TRPC) channels, phosphorylated eNOS and promoted NO generation in vascular endothelial cells. In addition, Jujuboside B-induced vasodilation involved

  7. Selective inhibition of human group IIA-secreted phospholipase A2 (hGIIA) signaling reveals arachidonic acid metabolism is associated with colocalization of hGIIA to vimentin in rheumatoid synoviocytes.

    PubMed

    Lee, Lawrence K; Bryant, Katherine J; Bouveret, Romaric; Lei, Pei-Wen; Duff, Anthony P; Harrop, Stephen J; Huang, Edwin P; Harvey, Richard P; Gelb, Michael H; Gray, Peter P; Curmi, Paul M; Cunningham, Anne M; Church, W Bret; Scott, Kieran F

    2013-05-24

    Human group IIA secreted phospholipase A2 (hGIIA) promotes tumor growth and inflammation and can act independently of its well described catalytic lipase activity via an alternative poorly understood signaling pathway. With six chemically diverse inhibitors we show that it is possible to selectively inhibit hGIIA signaling over catalysis, and x-ray crystal structures illustrate that signaling involves a pharmacologically distinct surface to the catalytic site. We demonstrate in rheumatoid fibroblast-like synoviocytes that non-catalytic signaling is associated with rapid internalization of the enzyme and colocalization with vimentin. Trafficking of exogenous hGIIA was monitored with immunofluorescence studies, which revealed that vimentin localization is disrupted by inhibitors of signaling that belong to a rare class of small molecule inhibitors that modulate protein-protein interactions. This study provides structural and pharmacological evidence for an association between vimentin, hGIIA, and arachidonic acid metabolism in synovial inflammation, avenues for selective interrogation of hGIIA signaling, and new strategies for therapeutic hGIIA inhibitor design.

  8. Selective Inhibition of Human Group IIA-secreted Phospholipase A2 (hGIIA) Signaling Reveals Arachidonic Acid Metabolism Is Associated with Colocalization of hGIIA to Vimentin in Rheumatoid Synoviocytes*

    PubMed Central

    Lee, Lawrence K.; Bryant, Katherine J.; Bouveret, Romaric; Lei, Pei-Wen; Duff, Anthony P.; Harrop, Stephen J.; Huang, Edwin P.; Harvey, Richard P.; Gelb, Michael H.; Gray, Peter P.; Curmi, Paul M.; Cunningham, Anne M.; Church, W. Bret; Scott, Kieran F.

    2013-01-01

    Human group IIA secreted phospholipase A2 (hGIIA) promotes tumor growth and inflammation and can act independently of its well described catalytic lipase activity via an alternative poorly understood signaling pathway. With six chemically diverse inhibitors we show that it is possible to selectively inhibit hGIIA signaling over catalysis, and x-ray crystal structures illustrate that signaling involves a pharmacologically distinct surface to the catalytic site. We demonstrate in rheumatoid fibroblast-like synoviocytes that non-catalytic signaling is associated with rapid internalization of the enzyme and colocalization with vimentin. Trafficking of exogenous hGIIA was monitored with immunofluorescence studies, which revealed that vimentin localization is disrupted by inhibitors of signaling that belong to a rare class of small molecule inhibitors that modulate protein-protein interactions. This study provides structural and pharmacological evidence for an association between vimentin, hGIIA, and arachidonic acid metabolism in synovial inflammation, avenues for selective interrogation of hGIIA signaling, and new strategies for therapeutic hGIIA inhibitor design. PMID:23482564

  9. Tributyltin chloride increases phenylephrine-induced contraction and vascular stiffness in mesenteric resistance arteries from female rats.

    PubMed

    Ribeiro Júnior, Rogério Faustino; Marques, Vinicius Bermond; Nunes, Dieli Oliveira; Ronconi, Karoline de Sousa; de Araújo, Julia F P; Rodrigues, Paula Lopes; Padilha, Alessandra Simão; Vassallo, Dalton Valentim; Graceli, Jones B; Stefanon, Ivanita

    2016-03-15

    Tributyltin chloride (TBT) is an organotin compound that reduces estrogen levels in female rats. We aimed to investigate the effects of TBT exposure on vascular tonus and vascular remodelling in the resistance arteries of female rats. Rats were treated daily with TBT (500 ng/kg) for 15 days. TBT did not change arterial blood pressure but did modify some morpho-physiological parameters of third-order mesenteric resistance arteries in the following ways: (1) decreased lumen and external diameters; (2) increased wall/lm ratio and wall thickness; (3) decreased distensibility and increased stiffness; (4) increased collagen deposition; and (5) increased pulse wave velocity. TBT exposure increased the phenylephrine-induced contractile response in mesenteric resistance arteries. However, vasodilatation responses induced by acetylcholine and sodium nitroprusside were not modified by TBT. It is suggested that TBT exposure reduces vascular nitric oxide (NO) production, because:(1) L-NAME incubation did not cause a leftward shift in the concentration-response curve for phenylephrine; (2) both eNOS protein expression; (3) in situ NO production were reduced. Incubation with L-NAME; and (4) SOD shifted the phenylephrine response curve to the left in TBT rats. Tiron, catalase, ML-171 and VAS2870 decreased vascular reactivity to phenylephrine only in TBT rats. Moreover, increased superoxide anion production was observed in the mesenteric resistance arteries of TBT rats accompanied by an increase in gp91phox, catalase, AT1 receptor and total ERK1/2 protein expression. In conclusion, these findings show that TBT induced alterations are most likely due to a reduction of NO production combined with increased O2(-) production derived from NADPH oxidase and ERK1/2 activation. These findings offer further evidence that TBT is an environmental risk factor for cardiovascular disease.

  10. Sodium nitrite attenuates hypertension-in-pregnancy and blunts increases in soluble fms-like tyrosine kinase-1 and in vascular endothelial growth factor.

    PubMed

    Gonçalves-Rizzi, Victor Hugo; Possomato-Vieira, Jose Sergio; Sales Graça, Tamiris Uracs; Nascimento, Regina Aparecida; Dias-Junior, Carlos A

    2016-07-01

    Preeclampsia is a pregnancy-associated disorder characterized by hypertension with uncertain pathogenesis. Increases in antiangiogenic soluble fms-like tyrosine kinase-1 (sFlt-1) and reductions in nitric oxide (NO) bioavailability have been observed in preeclamptic women. However, the specific mechanisms linking these detrimental changes to the hypertension-in-pregnancy are not clearly understood. In this regard, while recent findings have suggested that nitrite-derived NO formation exerts antihypertensive and antioxidant effects, no previous study has examined these responses to orally administered nitrite in hypertension-in-pregnancy. We then hypothesized restoring NO bioavailability with sodium nitrite in pregnant rats upon NO synthesis inhibition with N(omega)-nitro-l-arginine methyl ester (L-NAME) attenuates hypertension and high circulating levels of sFlt-1. Number and weight of pups and placentae were recorded to assess maternal-fetal interface. Plasma sFlt-1, vascular endothelial growth factor (VEGF) and biochemical determinants of NO formation and of antioxidant function were measured. We found that sodium nitrite blunts the hypertension-in-pregnancy and restores the NO bioavailability, and concomitantly prevents the L-NAME-induced high circulating sFlt-1 and VEGF levels. Also, our results suggest that nitrite-derived NO protected against reductions in litter size and placental weight caused by L-NAME, improving number of viable and resorbed fetuses and antioxidant function. Therefore, the present findings are consistent with the hypothesis that nitrite-derived NO may possibly be the driving force behind the maternal and fetal beneficial effects observed with sodium nitrite during hypertension-in-pregnancy. Certainly further investigations are required in preeclampsia, since counteracting the damages to the mother and fetal sides resulting from hypertension and elevated sFlt-1 levels may provide a great benefit in this gestational hypertensive disease

  11. P2 purinergic receptor activation of neuronal nitric oxide synthase and guanylyl cyclase in the dorsal facial area of the medulla increases blood flow in the common carotid arteries of cats.

    PubMed

    Hung, Y-W; Leung, Y-M; Lin, N-N; Lee, T J-F; Kuo, J-S; Tung, K-C; Gong, C-L

    2015-02-12

    In the dorsal facial area (DFA) of the medulla, an activation of either P2 purinergic receptor or nitric oxide synthase (NOS) results in the release of glutamate, leading to an increase in blood flow of the common carotid artery (CCA). It is not known whether activation of the P2 receptor by ATP may mediate activation of NOS/guanylyl cyclase to cause glutamate release and/or whether L-Arg (nitric oxide (NO) precursor) may also cause ATP release from any other neuron, to cause an increase in CCA flow. We demonstrated that microinjections of P2 receptor agonists (ATP, α,β-methylene ATP) or NO precursor (L-arginine) into the DFA increased CCA blood flow. The P2-induced CCA blood flow increase was dose-dependently reduced by pretreatment with NG-nitro-arginine methyl ester (L-NAME, a non-specific NOS inhibitor), 7-nitroindazole (7-NI, a relatively selective neuronal NOS inhibitor) or methylene blue (MB, a guanylyl cyclase inhibitor) but not by that with D-NAME (an isomer of L-NAME) or N5-(1-iminoethyl)-L-ornithine (L-NIO, a potent endothelial NOS inhibitor). Involvement of glutamate release in these responses were substantiated by microdialysis studies, in which perfusions of ATP into the DFA increased the glutamate concentration in dialysates, but co-perfusion of ATP with L-NAME or 7-NI did not. Nevertheless, the arginine-induced CCA blood flow increase was abolished by combined pretreatment of L-NAME and MB, but not affected by pretreatment with a selective P2 receptor antagonist, pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS). In conclusion, ATP activation of the P2 receptor in the DFA induced activation of neuronal NOS/guanylyl cyclase, which causes glutamate release leading to an increase in CCA blood flow. However, arginine activation of neuronal NOS/guanylyl cyclase, which also caused glutamate release and CCA blood flow increase, did not induce activation of P2 receptors. These findings provide important information for drug design and

  12. P2 purinergic receptor activation of neuronal nitric oxide synthase and guanylyl cyclase in the dorsal facial area of the medulla increases blood flow in the common carotid arteries of cats.

    PubMed

    Hung, Y-W; Leung, Y-M; Lin, N-N; Lee, T J-F; Kuo, J-S; Tung, K-C; Gong, C-L

    2015-02-12

    In the dorsal facial area (DFA) of the medulla, an activation of either P2 purinergic receptor or nitric oxide synthase (NOS) results in the release of glutamate, leading to an increase in blood flow of the common carotid artery (CCA). It is not known whether activation of the P2 receptor by ATP may mediate activation of NOS/guanylyl cyclase to cause glutamate release and/or whether L-Arg (nitric oxide (NO) precursor) may also cause ATP release from any other neuron, to cause an increase in CCA flow. We demonstrated that microinjections of P2 receptor agonists (ATP, α,β-methylene ATP) or NO precursor (L-arginine) into the DFA increased CCA blood flow. The P2-induced CCA blood flow increase was dose-dependently reduced by pretreatment with NG-nitro-arginine methyl ester (L-NAME, a non-specific NOS inhibitor), 7-nitroindazole (7-NI, a relatively selective neuronal NOS inhibitor) or methylene blue (MB, a guanylyl cyclase inhibitor) but not by that with D-NAME (an isomer of L-NAME) or N5-(1-iminoethyl)-L-ornithine (L-NIO, a potent endothelial NOS inhibitor). Involvement of glutamate release in these responses were substantiated by microdialysis studies, in which perfusions of ATP into the DFA increased the glutamate concentration in dialysates, but co-perfusion of ATP with L-NAME or 7-NI did not. Nevertheless, the arginine-induced CCA blood flow increase was abolished by combined pretreatment of L-NAME and MB, but not affected by pretreatment with a selective P2 receptor antagonist, pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS). In conclusion, ATP activation of the P2 receptor in the DFA induced activation of neuronal NOS/guanylyl cyclase, which causes glutamate release leading to an increase in CCA blood flow. However, arginine activation of neuronal NOS/guanylyl cyclase, which also caused glutamate release and CCA blood flow increase, did not induce activation of P2 receptors. These findings provide important information for drug design and

  13. DIFFERENTIAL EFFECTS OF POLYBROMINATED DIPHENYL ETHERS AND POLYCHLORINATED BIPHENYLS ON [3H]ARACHIDONIC ACID RELEASE IN RAT CEREBELLAR GRANULE NEURONS.

    EPA Science Inventory

    Polybrominated diphenyl ethers (PBDEs), which are widely used as flame-retardants, have been increasing in the past 20-30 years while the presence of other structurally related persistent organic pollutants, such as polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-d...

  14. Leptin protection of salivary gland acinar cells against ethanol cytotoxicity involves Src kinase-mediated parallel activation of prostaglandin and constitutive nitric oxide synthase pathways.

    PubMed

    Slomiany, B L; Slomiany, A

    2008-04-01

    Leptin, a pleiotropic cytokine secreted by adipocytes but also identified in salivary glands and saliva, is recognized as an important element of oral mucosal defense. Here, we report that in sublingual salivary glands leptin protects the acinar cells of against ethanol cytotoxicity. We show that ethanol- induced cytotoxicity, characterized by a marked drop in the acinar cell capacity for NO production, arachidonic acid release and prostaglandin generation, was subject to suppression by leptin. The loss in countering capacity of leptin on the ethanol-induced cytotoxicity was attained with cyclooxygenase inhibitor, indomethacin and nitric oxide synthase (cNOS) inhibitor, L-NAME, as well as PP2, an inhibitor of Src kinase. Indomethacin, while not affecting leptin-induced arachidonic acid release, caused the inhibition in PGE2 generation, pretreatment with L-NAME led to the inhibition in NO production, whereas PP2 exerted the inhibitory effect on leptin-induced changes in NO, arachidonic acid, and PGE2. The leptin-induced changes in arachidonic acid release and PGE2 generation were blocked by ERK inhibitor, PD98059, but not by PI3K inhibitor, wortmannin. Further, leptin suppression of ethanol cytotoxicity was reflected in the increased Akt and cNOS phosphorylation that was sensitive to PP2. Moreover, the stimulatory effect of leptin on the acinar cell cNOS activity was inhibited not only by PP2, but also by Akt inhibitor, SH-5, while wortmannin had no effect. Our findings demonstrate that leptin protection of salivary gland acinar cells against ethanol cytotoxicity involves Src kinase-mediated parallel activation of MAPK/ERK and Akt that result in up-regulation of the respective prostaglandin and nitric oxide synthase pathways.

  15. Increased expression of leukotriene C4 synthase and predominant formation of cysteinyl-leukotrienes in human abdominal aortic aneurysm

    PubMed Central

    Di Gennaro, Antonio; Wågsäter, Dick; Mäyränpää, Mikko I.; Gabrielsen, Anders; Swedenborg, Jesper; Hamsten, Anders; Samuelsson, Bengt; Eriksson, Per; Haeggström, Jesper Z.

    2010-01-01

    Leukotrienes (LTs) are arachidonic acid-derived lipid mediators involved in the pathogenesis and progression of diverse inflammatory disorders. The cysteinyl-leukotrienes LTC4, LTD4, and LTE4 are important mediators of asthma, and LTB4 has recently been implicated in atherosclerosis. Here we report that mRNA levels for the three key enzymes/proteins in the biosynthesis of cysteinyl-leukotrienes, 5-lipoxygenase (5-LO), 5-LO-activating protein (FLAP), and LTC4 synthase (LTC4S), are significantly increased in the wall of human abdominal aortic aneurysms (AAAs). In contrast, mRNA levels of LTA4 hydrolase, the enzyme responsible for the biosynthesis of LTB4, are not increased. Immunohistochemical staining of AAA wall revealed focal expression of 5-LO, FLAP, and LTC4S proteins in the media and adventitia, localized in areas rich in inflammatory cells, including macrophages, neutrophils, and mast cells. Human AAA wall tissue converts arachidonic acid and the unstable epoxide LTA4 into significant amounts of cysteinyl-leukotrienes and to a lesser extent LTB4. Furthermore, challenge of AAA wall tissue with exogenous LTD4 increases the release of matrix metalloproteinase (MMP) 2 and 9, and selective inhibition of the CysLT1 receptor by montelukast blocks this effect. The increased expression of LTC4S, together with the predominant formation of cysteinyl-leukotrienes and effects on MMPs production, suggests a mechanism by which LTs may promote matrix degradation in the AAA wall and identify the components of the cysteinyl-leukotriene pathway as potential targets for prevention and treatment of AAA. PMID:21078989

  16. Increased brain nitric oxide levels following ethanol administration.

    PubMed

    Finnerty, Niall; O'Riordan, Saidhbhe L; Klamer, Daniel; Lowry, John; Pålsson, Erik

    2015-05-01

    Nitric oxide is a ubiquitous messenger molecule, which at elevated concentrations has been implicated in the pathogenesis of several neurological disorders. Its role in oxidative stress, attributed in particular to the formation of peroxynitrite, proceeds through its high affinity for the superoxide radical. Alcoholism has recently been associated with the induction of oxidative stress, which is generally defined as a shift in equilibrium between pro-oxidant and anti-oxidant species in the direction of the former. Furthermore, its primary metabolite acetaldehyde, has been extensively associated with oxidative damage related toxic effects following alcohol ingestion. The principal objective of this study was the application of long term in vivo electrochemistry (LIVE) to investigate the effect of ethanol (0.125, 0.5 and 2.0 g kg(-1)) and acetaldehyde (12.5, 50 and 200 mg kg(-1)) on NO levels in the nucleus accumbens of freely moving rats. Systemic administrations of ethanol and acetaldehyde resulted in a dose-dependent increases in NO levels, albeit with very differing time courses. Subsequent to this the effect on accumbal NO levels, of subjecting the animal to different drug combinations, was also elucidated. The nitric oxide synthase inhibitor L-NAME (20 mg kg(-1)) and acetaldehyde sequestering agent D-penicillamine (50 mg kg(-1)) both attenuated the increase in NO levels following ethanol (1 g kg(-1)) administration. Conversely, the alcohol dehydrogenase inhibitor 4-methylpyrazole (25 mg kg(-1)) and catalase inhibitor sodium azide (10 mg kg(-1)) potentiated the increase in NO levels following ethanol administration. Finally, dual inhibition of aldehyde dehydrogenase and catalase by cyanamide (25 mg kg(-1)) caused an attenuation of ethanol effects on NO levels. Taken together these data highlight a robust increase in brain NO levels following systemic alcohol administration which is dependent on NO synthase activity and may involve both alcohol- and acetaldehyde

  17. Effects of large doses of arachidonic acid added to docosahexaenoic acid on social impairment in individuals with autism spectrum disorders: a double-blind, placebo-controlled, randomized trial.

    PubMed

    Yui, Kunio; Koshiba, Mamiko; Nakamura, Shun; Kobayashi, Yuji

    2012-04-01

    Autism spectrum disorders are a neurodevelopmental disorders with reduced cortical functional connectivity relating to social cognition. Polyunsaturated fatty acids arachidonic acid (ARA) and docosahexaenoic acid (DHA) may have key role in brain network maturation. In particularly, ARA is important in signal transduction related to neuronal maturation. Supplementation with larger ARA doses added to DHA may therefore mitigate social impairment. In a 16-week, double-blind, randomized, placebo-controlled trial, we evaluated the efficacy of supplementation with large doses of ARA added to DHA (n = 7) or placebo (n = 6) in 13 participants (mean age, 14.6 [SD, 5.9] years). To examine underlying mechanisms underlying the effect of our supplementation regimen, we examined plasma levels of antioxidants transferrin and superoxide dismutase, which are useful markers of signal transduction. The outcome measures were the Social Responsiveness Scale and the Aberrant Behavior Checklist-Community. Repeated-measures analysis of variance revealed that our supplementation regimen significantly improved Aberrant Behavior Checklist-Community-measured social withdrawal and Social Responsiveness Scale-measured communication. Treatment effect sizes were more favorable for the treatment group compared with the placebo group (communication: treatment groups, 0.87 vs, placebo, 0.44; social withdrawal: treatment groups, 0.88, vs placebo, 0.54). There was a significant difference in the change in plasma transferrin levels and a trend toward a significant difference in the change in plasma superoxide dismutase levels between the 2 groups. This preliminary study suggests that supplementation with larger ARA doses added to DHA improves impaired social interaction in individuals with autism spectrum disorder by up-regulating signal transduction.

  18. Pro-oxidant activity of indicaxanthin from Opuntia ficus indica modulates arachidonate metabolism and prostaglandin synthesis through lipid peroxide production in LPS-stimulated RAW 264.7 macrophages.

    PubMed

    Allegra, M; D'Acquisto, F; Tesoriere, L; Attanzio, A; Livrea, M A

    2014-01-01

    Macrophages come across active prostaglandin (PG) metabolism during inflammation, shunting early production of pro-inflammatory towards anti-inflammatory mediators terminating the process. This work for the first time provides evidence that a phytochemical may modulate the arachidonate (AA) metabolism in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages, promoting the ultimate formation of anti-inflammatory cyclopentenone 15deoxy-PGJ2. Added 1 h before LPS, indicaxanthin from Opuntia Ficus Indica prevented activation of nuclear factor-κB (NF-κB) and over-expression of PGE2 synthase-1 (mPGES-1), but up-regulated cyclo-oxygenase-2 (COX-2) and PGD2 synthase (H-PGDS), with final production of the anti-inflammatory cyclopentenone. The effects were positively related with concentration between 50 and 100 µM. Indicaxanthin did not have any effect in the absence of LPS. A kinetic study investigating the redox status of LPS-stimulated macrophages between 0.5 and 12 h, either in the absence or in the presence of 50-100 µM indicaxanthin, revealed a differential control of ROS production, with early (0.5-3 h) modest inhibition, followed by a progressive (3-12 h) concentration-dependent enhancement over the level induced by LPS alone. In addition, indicaxanthin caused early (0.5-3 h) concentration-dependent elevation of conjugated diene lipid hydroperoxides, and production of hydroxynonenal-protein adducts, over the amount induced by LPS. In LPS-stimulated macrophages indicaxanthin did not affect PG metabolism when co-incubated with either an inhibitor of NADPH oxidase or vitamin E. It is concluded that LPS-induced pro-oxidant activity of indicaxanthin at the membrane level allows formation of signaling intermediates whose accumulation modulates PG biosynthetic pathway in inflamed macrophages.

  19. Dietary supplementation with arachidonic acid but not eicosapentaenoic or docosahexaenoic acids alter lipids metabolism in C57BL/6J mice.

    PubMed

    Magdeldin, Sameh; Elewa, Yaser; Ikeda, Takako; Ikei, Junko; Zhang, Ying; Xu, Bo; Nameta, Masaaki; Fujinaka, Hidehiko; Yoshida, Yutaka; Yaoita, Eishin; Yamamoto, Tadashi

    2009-09-01

    In order to investigate the effects of dietary supplementation rich in omega 3 and omega 6 fatty acids, we set up an experiment of twenty four C57BL/6J male mice segregated into 3 groups: normal diet (ND), omega 3 polyunsaturated fatty acid (n-3 PUFA,) and omega 6 (n-6 PUFA). At the end of the experiment that lasted for 1 month, food consumption of ND and n-3 PUFA were similar while it decreased in n-6 PUFA group. Total cholesterol, triglycerides, free fatty acids, and phospholipids profiles were increased in n-6 PUFA. LDL decreased in n-3 PUFA while increased in n-6 PUFA fed mice comparing to control group. On the other hand, there was no difference between treatments in HDL and glucose levels. Expression of leptin (ob) gene transcripts in epididymal fat were significantly elevated in n-6 PUFA mice compared to ND and n-3 PUFA groups while hypothalamic ob receptor A (obRa) mRNA did not changed in response to diet regimes. Transmission and scanning electron microscopy showed different degrees in fatty changes in the liver of both PUFA groups including lipid droplet infiltration and Ito cells with over accumulated lipids. In conclusion, under PUFA dietary supplementation, the hyperlipidemic status and elevated ob expression of n-6 PUFA but not n-3 PUFA fed mice suggests altered lipid metabolism between PUFA groups and/or different endocrine involvement. Moreover, the coincidently structural changes observed in liver of this group direct us to call for further studies to investigate the anti-obesity effect and safety of these PUFA under high supplementation condition.

  20. Enteral Arginine Does Not Increase Superior Mesenteric Arterial Blood Flow but Induces Mucosal Growth in Neonatal Pigs123

    PubMed Central

    Puiman, Patrycja J.; Stoll, Barbara; van Goudoever, Johannes B.; Burrin, Douglas G.

    2011-01-01

    Arginine is an essential amino acid in neonates synthesized by gut epithelial cells and a precursor for NO that regulates vasodilatation and blood flow. Arginine supplementation has been shown to improve intestinal integrity in ischemia-reperfusion models and low plasma levels are associated with necrotizing enterocolitis. We hypothesized that enteral arginine is a specific stimulus for neonatal intestinal blood flow and mucosal growth under conditions of total parenteral nutrition (TPN) or partial enteral nutrition (PEN). We first tested the dose dependence and specificity of acute (3 h) enteral arginine infusion on superior mesenteric artery (SMA) blood flow in pigs fed TPN or PEN. We then determined whether chronic (4 d) arginine supplementation of PEN increases mucosal growth and if this was affected by treatment with the NO synthase inhibitor, NG-nitro-l-arginine methyl ester (L-NAME). Acute enteral arginine infusion increased plasma arginine dose dependently in both TPN and PEN groups, but the plasma response was markedly higher (100–250%) in the PEN group than in the TPN group at the 2 highest arginine doses. Baseline SMA blood flow was 90% higher in the PEN (2.37 ± 0.32 L⋅kg−1⋅h−1) pigs than in the TPN pigs (1.23 ± 0.17 L⋅kg−1⋅h−1), but was not affected by acute infusion individually of arginine, citrulline, or other major gut fuels. Chronic dietary arginine supplementation in PEN pigs induced mucosal growth in the intestine, but this effect was not prevented by treatment with L-NAME. Intestinal crypt cell proliferation, protein synthesis, and phosphorylation of mammalian target of rapamycin and p70S6 kinase were not affected by dietary arginine. We conclude that partial enteral feeding, but not acute enteral arginine, increases SMA blood flow in the neonatal pig. Furthermore, supplementing arginine in partial enteral feeding modestly increases intestinal mucosal growth and was NO independent. PMID:21106927

  1. The arachidonic acid metabolite 11β-ProstaglandinF2α controls intestinal epithelial healing: deficiency in patients with Crohn’s disease

    PubMed Central

    Coquenlorge, Sabrina; Van Landeghem, Laurianne; Jaulin, Julie; Cenac, Nicolas; Vergnolle, Nathalie; Duchalais, Emilie; Neunlist, Michel; Rolli-Derkinderen, Malvyne

    2016-01-01

    In healthy gut enteric glial cells (EGC) are essential to intestinal epithelial barrier (IEB) functions. In Crohn’s Disease (CD), both EGC phenotype and IEB functions are altered, but putative involvement of EGC in CD pathogenesis remains unknown and study of human EGC are lacking. EGC isolated from CD and control patients showed similar expression of glial markers and EGC-derived soluble factors (IL6, TGF-β, proEGF, GSH) but CD EGC failed to increase IEB resistance and healing. Lipid profiling showed that CD EGC produced decreased amounts of 15-HETE, 18-HEPE, 15dPGJ2 and 11βPGF2α as compared to healthy EGC. They also had reduced expression of the L-PGDS and AKR1C3 enzymes. Produced by healthy EGC, the 11βPGF2 activated PPARγ receptor of intestinal epithelial cells to induce cell spreading and IEB wound repair. In addition to this novel healing mechanism our data show that CD EGC presented impaired ability to promote IEB functions through defect in L-PGDS-AKR1C3-11βPGF2α dependent pathway. PMID:27140063

  2. The arachidonic acid metabolite 11β-ProstaglandinF2α controls intestinal epithelial healing: deficiency in patients with Crohn's disease.

    PubMed

    Coquenlorge, Sabrina; Van Landeghem, Laurianne; Jaulin, Julie; Cenac, Nicolas; Vergnolle, Nathalie; Duchalais, Emilie; Neunlist, Michel; Rolli-Derkinderen, Malvyne

    2016-01-01

    In healthy gut enteric glial cells (EGC) are essential to intestinal epithelial barrier (IEB) functions. In Crohn's Disease (CD), both EGC phenotype and IEB functions are altered, but putative involvement of EGC in CD pathogenesis remains unknown and study of human EGC are lacking. EGC isolated from CD and control patients showed similar expression of glial markers and EGC-derived soluble factors (IL6, TGF-β, proEGF, GSH) but CD EGC failed to increase IEB resistance and healing. Lipid profiling showed that CD EGC produced decreased amounts of 15-HETE, 18-HEPE, 15dPGJ2 and 11βPGF2α as compared to healthy EGC. They also had reduced expression of the L-PGDS and AKR1C3 enzymes. Produced by healthy EGC, the 11βPGF2 activated PPARγ receptor of intestinal epithelial cells to induce cell spreading and IEB wound repair. In addition to this novel healing mechanism our data show that CD EGC presented impaired ability to promote IEB functions through defect in L-PGDS-AKR1C3-11βPGF2α dependent pathway. PMID:27140063

  3. Attenuation of Thrombosis by Crude Rice (Oryza sativa) Bran Policosanol Extract: Ex Vivo Platelet Aggregation and Serum Levels of Arachidonic Acid Metabolites

    PubMed Central

    Ismail, Maznah; Tohit, Eusni Rahayu Mohd; Abdullah, Rasedee; Zhang, Yi-Da

    2016-01-01

    Background. Vascular occlusion or thrombosis was often attributed to uncontrolled platelet activation. Influence of sugarcane policosanol extract on platelet was reported but little was known of rice bran policosanol, particularly its mechanisms of actions on platelet activities. Objective. Antiplatelet mechanisms of rice bran policosanol extract (RBE) were studied using hyperlipidemic Sprague Dawley rats. Ex vivo platelet aggregation, platelet count (PC), bleeding time (BT), and coagulation time were assayed. Serum eicosanoids and other aggregation-related metabolites levels were quantified. Design. Rats were divided into 6 groups for comparisons (vehicle control Tween 20/H2O, high dose policosanol 500 mg/kg, middle dose policosanol 250 mg/kg, low dose policosanol 100 mg/kg, and positive control aspirin 30 mg/kg). Results. Low dose 100 mg/kg of RBE inhibited aggregation by 42.32 ± 4.31% and this was comparable with the effect of 30 mg/kg aspirin, 43.91 ± 5.27%. Results showed that there were no significant differences in PC, BT, and coagulation time among various groups after RBE treatment. Serum thromboxane A2 was attenuated while prostacyclin level increased upon RBE treatment. Conclusions. RBE reduced ex vivo ADP-induced platelet aggregation without giving adverse effects. No changes in full blood count suggested that rice bran policosanol did not disturb biological blood cell production and destruction yet it reduced aggregation through different mechanisms. PMID:27800004

  4. Neurotoxic lipid peroxidation species formed by ischemic stroke increase injury

    PubMed Central

    Zeiger, Stephanie L. H.; Musiek, Erik S.; Zanoni, Giuseppe; Vidari, Giovanni; Morrow, Jason D.; Milne, Ginger J.; McLaughlin, BethAnn

    2009-01-01

    Stroke is the third leading cause of death in the United States yet no neuroprotective agents for treatment are clinically available. There is a pressing need to understand the signaling molecules which mediate ischemic cell death and identify novel neuroprotective targets. Cyclopentenone isoprostanes (IsoP), formed following free radical mediated peroxidation of arachidonic acid, are used as markers of stress but their bioactivity is poorly understood. We have recently shown that 15-A2t-Isop is a potent neurotoxin in vitro and increases the free radical burden in neurons. In this work, we demonstrate that 15-A2t-IsoP is abundantly produced in stroke infarcted human cortical tissue. Using primary neuronal cultures we found that minimally toxic exposure to 15-A2t-IsoP does not alter ATP content, but in combination with oxygen glucose deprivation resulted in a significant hyperpolarization of the mitochondrial membrane and dramatically increased neuronal cell death. In the presence of Ca2+, 15-A2t-IsoP led to a rapid induction of the permeability transition pore and release of cytochrome c. Taken with our previous work, these data support a model in which ischemia causes generation of reactive oxygen species, calcium influx, lipid peroxidation and 15-A2t-IsoP formation. These factors combine to enhance opening of the permeability transition pore leading to cell death subsequent to mitochondrial cytochrome c release. This data is the first documentation of significant 15-A2t-IsoP formation following acute ischemic stroke and suggests addition of 15-A2t-IsoP to in vitro models of ischemia may help to more fully recapitulate stroke injury. PMID:19699297

  5. Insulin rapidly increases diacylglycerol by activating de novo phosphatidic acid synthesis.

    PubMed

    Farese, R V; Konda, T S; Davis, J S; Standaert, M L; Pollet, R J; Cooper, D R

    1987-05-01

    The mechanisms whereby insulin increases diacylglycerol in BC3H-1 myocytes were examined. When [3H]arachidonate labeling of phospholipids was used as an indicator of phospholipase C activation, transient increases in [3H]diacylglycerol were observed between 0.5 and 10 minutes after the onset of insulin treatment. With [3H]glycerol labeling as an indicator of de novo phospholipid synthesis, [3H]diacylglycerol was increased maximally at 1 minute and remained elevated for 20 minutes. [3H]Glycerol-labeled diacylglycerol was largely derived directly from phosphatidic acid. Insulin increased de novo phosphatidic acid synthesis within 5 to 10 seconds; within 1 minute, this synthesis was 60 times greater than that of controls. Thus, the initial increase in diacylglycerol is due to both increased hydrolysis of phospholipids and a burst of de novo phosphatidic acid synthesis. After 5 to 10 minutes, de novo phosphatidic acid synthesis continues as a major source of diacylglycerol. Both phospholipid effects of insulin seem important for generating diacylglycerol and other phospholipid-derived intracellular signaling substances.

  6. Effects of synthetic sphingosine-1-phosphate analogs on cytosolic phospholipase A2alpha-independent release of arachidonic acid and cell toxicity in L929 fibrosarcoma cells: the structure-activity relationship.

    PubMed

    Shimizu, Masaya; Muramatsu, Yuki; Tada, Eiko; Kurosawa, Takeshi; Yamaura, Erika; Nakamura, Hiroyuki; Fujino, Hiromichi; Houjyo, Yuuya; Miyasaka, Yuri; Koide, Yuuki; Nishida, Atsushi; Murayama, Toshihiko

    2009-03-01

    Sphingolipid metabolites including ceramide, sphingosine, and their phosphorylated products [sphingosine-1-phosphate (S1P) and ceramide-1-phosphate] regulate cell functions including arachidonic acid (AA) metabolism and cell death. The development of analogs of S1P may be useful for regulating these mediator-induced cellular responses. We synthesized new analogs of S1P and examined their effects on the release of AA and cell death in L929 mouse fibrosarcoma cells. Among the analogs tested, several compounds including DMB-mC11S [dimethyl (2S,3R)-2-tert-butoxycarbonylamino-3-hydroxy-3-(3'-undecyl)phenylpropyl phosphate] and DMB-mC9S [dimethyl (2S,3R)-2-tert-butoxycarbonylamino-3-hydroxy-3-(3'-nonyl)phenylpropyl phosphate] released AA within 1 h and caused cell death 6 h after treatment. The release of AA was observed in C12 cells [a L929 variant lacking a type alpha cytosolic phospholipase A(2) (cPLA(2)alpha)] and L929-cPLAalpha-siRNA cells (L929 cells treated with small interference RNA for cPLA(2)alpha). Treatment with pharmacological inhibitors of secretory and Ca(2+)-independent PLA(2)s decreased the DMB-mC11S-induced release of AA. The effect of the S1P analogs tested on the release of AA was comparable to that on cell death in L929 cells, and a high correlation coefficient was observed. Two analogs lacking a butoxycarbonyl moiety [DMAc-mC11S (dimethyl (2S,3R)-2-acetamino-3-hydroxy-3-(3'-undecyl)phenylpropyl phosphate] and DMAm-mC11S [dimethyl (2S,3R)-2-amino-3-hydroxy-3-(3'-undecyl)phenylpropyl phosphate)] had inhibitory effects on the release of AA and cell toxicity induced by DMB-mC11S. Synthetic phosphorylated lipid analogs may be useful for studying PLA(2) activity and its toxicity in cells. [Supplementary Fig. 1: available only at http://dx.doi.org/10.1254/jphs.08284FP].

  7. Increased prostaglandins E2 and F2α in human skin at 6 and 24 h after ultraviolet B irradiation (290-320 nm)

    PubMed Central

    Kobza Black, A.; Greaves, M. W.; Hensby, C. N.; Plummer, N. A.

    1978-01-01

    1 Abdominal skin of 25 human subjects was irradiated with three times its minimal erythema dose of ultraviolet (u.v.) B radiation. Erythema appeared after 2 h, was of moderate degree at 6 h, and maximal at 24 and 48 h. 2 Exudate was recovered by a suction bulla technique from the subject's normal and erythematous skin either at 6, 24 or 48 h after irradiation. 3 Superfusion cascade bioassay of exudate showed increased prostaglandin (PG)-like activity, measured in PGE2 equivalents, at 6 and 24 h after irradiation. The maximum rise was at 24 h, coinciding with the peak of the erythema. However, prostaglandin concentrations were not significantly above that of controls at 48 h when the erythema was still maximal. 4 Radioimmunoassay for PGF2α yielded values in close agreement with the bioassay results. 5 Gel partition chromatography, after conversion of extracted residues from the exudate to 14C methyl esters, showed increased incorporation of radioactivity at 6 h, maximal at 24 h. At 48 h there was no significant difference from control levels. The major increased activity, maximal at 24 h, co-chromatographed with arachidonic acid and PGE2 and PGF2α. The materials provisionally identified as the latter three compounds also co-chromatographed with their corresponding methyl esters on t.l.c., although the arachidonic acid-like material contained at least two peaks. No evidence was obtained for the 1 or 3 series of PGs. On g.l.c. the material obtained from the PGF2α zone co-chromatographed with authentic PGF2α as the methyl ester trimethylsilyl ether. The PGE2 zone converted to methyl ester n-butyloxime trimethylsilyl ether also co-chromatographed with authentic PGE2, but with some distinct shouldering. 6 The evidence presented provides support for the presence of increased amounts of arachidonic acid, PGE2 and PGF2α-like compounds during the first 24 h of u.v.B erythema, with concordance of the erythema and prostaglandin levels. At 48 h this relationship could not

  8. Histamine Induces Vascular Hyperpermeability by Increasing Blood Flow and Endothelial Barrier Disruption In Vivo.

    PubMed

    Ashina, Kohei; Tsubosaka, Yoshiki; Nakamura, Tatsuro; Omori, Keisuke; Kobayashi, Koji; Hori, Masatoshi; Ozaki, Hiroshi; Murata, Takahisa

    2015-01-01

    Histamine is a mediator of allergic inflammation released mainly from mast cells. Although histamine strongly increases vascular permeability, its precise mechanism under in vivo situation remains unknown. We here attempted to reveal how histamine induces vascular hyperpermeability focusing on the key regulators of vascular permeability, blood flow and endothelial barrier. Degranulation of mast cells by antigen-stimulation or histamine treatment induced vascular hyperpermeability and tissue swelling in mouse ears. These were abolished by histamine H1 receptor antagonism. Intravital imaging showed that histamine dilated vasculature, increased blood flow, while it induced hyperpermeability in venula. Whole-mount staining showed that histamine disrupted endothelial barrier formation of venula indicated by changes in vascular endothelial cadherin (VE-cadherin) localization at endothelial cell junction. Inhibition of nitric oxide synthesis (NOS) by L-NAME or vasoconstriction by phenylephrine strongly inhibited the histamine-induced blood flow increase and hyperpermeability without changing the VE-cadherin localization. In vitro, measurements of trans-endothelial electrical resistance of human dermal microvascular endothelial cells (HDMECs) showed that histamine disrupted endothelial barrier. Inhibition of protein kinase C (PKC) or Rho-associated protein kinase (ROCK), NOS attenuated the histamine-induced barrier disruption. These observations suggested that histamine increases vascular permeability mainly by nitric oxide (NO)-dependent vascular dilation and subsequent blood flow increase and maybe partially by PKC/ROCK/NO-dependent endothelial barrier disruption.

  9. Decreased ovarian reserve, dysregulation of mitochondrial biogenesis, and increased lipid peroxidation in female mouse offspring exposed to an obesogenic maternal diet

    PubMed Central

    Aiken, Catherine E.; Tarry-Adkins, Jane L.; Penfold, Naomi C.; Dearden, Laura; Ozanne, Susan E.

    2016-01-01

    Maternal diet during pregnancy influences the later life reproductive potential of female offspring. We investigate the molecular mechanisms underlying the depletion of ovarian follicular reserve in young adult females following exposure to obesogenic diet in early life. Furthermore, we explore the interaction between adverse maternal diet and postweaning diet in generating reduced ovarian reserve. Female mice were exposed to either maternal obesogenic (high fat/high sugar) or maternal control diet in utero and during lactation, then weaned onto either obesogenic or control diet. At 12 wk of age, the offspring ovarian reserve was depleted following exposure to maternal obesogenic diet (P < 0.05), but not postweaning obesogenic diet. Maternal obesogenic diet was associated with increased mitochondrial DNA biogenesis (copy number P < 0.05; transcription factor A, mitochondrial expression P < 0.05), increased mitochondrial antioxidant defenses [manganese superoxide dismutase (MnSOD) P < 0.05; copper/zinc superoxide dismutase P < 0.05; glutathione peroxidase 4 P < 0.01] and increased lipoxygenase expression (arachidonate 12-lipoxygenase P < 0.05; arachidonate 15-lipoxygenase P < 0.05) in the ovary. There was also significantly increased expression of the transcriptional regulator NF-κB (P < 0.05). There was no effect of postweaning diet on any measured ovarian parameters. Maternal diet thus plays a central role in determining follicular reserve in adult female offspring. Our observations suggest that lipid peroxidation and mitochondrial biogenesis are the key intracellular pathways involved in programming of ovarian reserve.—Aiken, C. E., Tarry-Adkins, J. L., Penfold, N. C., Dearden, L., Ozanne, S. E. Decreased ovarian reserve, dysregulation of mitochondrial biogenesis, and increased lipid peroxidation in female mouse offspring exposed to an obesogenic maternal diet. PMID:26700734

  10. Transcriptome Analysis in Rat Kidneys: Importance of Genes Involved in Programmed Hypertension

    PubMed Central

    Tain, You-Lin; Huang, Li-Tung; Chan, Julie Y. H.; Lee, Chien-Te

    2015-01-01

    Suboptimal conditions in pregnancy can elicit long-term effects on the health of offspring. The most common outcome is programmed hypertension. We examined whether there are common genes and pathways in the kidney are responsible for generating programmed hypertension among three different models using next generation RNA sequencing (RNA-Seq) technology. Pregnant Sprague-Dawley rats received dexamethasone (DEX, 0.1 mg/kg) from gestational day 16 to 22, 60% high-fructose (HF) diet, or NG-nitro-l-arginine-methyester (l-NAME, 60 mg/kg/day) to conduct DEX, HF, or l-NAME model respectively. All three models elicited programmed hypertension in adult male offspring. We observed five shared genes (Bcl6, Dmrtc1c, Egr1, Inmt, and Olr1668) among three different models. The identified differential genes (DEGs) that are related to regulation of blood pressure included Aqp2, Ptgs1, Eph2x, Hba-a2, Apln, Guca2b, Hmox1, and Npy. RNA-Seq identified genes in arachidonic acid metabolism are potentially gatekeeper genes contributing to programmed hypertension. In addition, HF and DEX increased expression and activity of soluble epoxide hydrolase (Ephx2 gene encoding protein). Conclusively, the DEGs in arachidonic acid metabolism are potentially gatekeeper genes in programmed hypertension. The roles of DEGs identified by the RNA-Seq in this study deserve further clarification, to develop the potential interventions in the prevention of programmed hypertension. PMID:25739086

  11. Solute concentration affects bradykinin-mediated increases in renal prostaglandin E2

    SciTech Connect

    Zenser, T.V.; Davis, E.S.; Rapp, N.S.; Davis, B.B.

    1981-12-01

    The effects of solute concentration on the bradykinin-mediated increase in inner medullary slice prostaglandin E2 (PGE2) synthesis were investigated. PG content was determined by specific RIA. Bradykinin stimulation was prevented by the addition of the following solutes to Krebs buffer: 1.0 M urea, 0.5 or 1.0 M NaCl, 0.5 or 1.0 M mannitol, 1.0 M urea plus 0.5 M NaCl, or 1.0 M mannitol plus 0.5 M NaCl. By contrast, basal PGE2 synthesis was increased by 1.0 M mannitol or by 1.0 M mannitol plus 0.5 M NaCl, but decreased by 1.0 M urea. Urea elicited a concentration-dependent, reversible inhibition of bradykinin stimulation, with 0.01 M urea being the lowest effective concentration. By contrast, basal PGE2 synthesis was only reduced at a urea concentration greater than 0.6 M. Arachidonic acid-mediated increases in both PGE2 and PGF2 alpha synthesis were not prevented by 1.0 M urea. The latter suggests that neither PG endoperoxide synthetase nor PG endoperoxide E isomerase are inhibited by urea. The data indicate that different hypertonic solutions have different effects on basal PG production, but all inhibit bradykinin stimulation.

  12. Simvastatin Increases Fibulin-2 Expression in Human Coronary Artery Smooth Muscle Cells via RhoA/Rho-Kinase Signaling Pathway Inhibition

    PubMed Central

    Serra, Noemí; Rosales, Roser; Masana, Lluís; Vallvé, Joan-Carles

    2015-01-01

    The composition and structure of the extracellular matrix (ECM) in the vascular wall and in the atherosclerotic plaque are important factors that determine plaque stability. Statins can stabilize atherosclerotic plaques by modulating ECM protein expression. Fibulins are important components of the ECM. We evaluated the in vitro effect of simvastatin on the expression of fibulin-1, -2, -4 and -5 in human coronary artery smooth muscle cells (SMCs) and the mechanisms involved. Cells were incubated with simvastatin (0.05–1 μM), mevalonate (100 and 200 μM), geranylgeranyl pyrophosphate (GGPP) (15 μM), farnesyl pyrophosphate (FPP) (15 μM), the Rho kinase (ROCK) inhibitor Y-27632 (15 and 20 μM), the Rac-1 inhibitor (another member of Rho family) NSC23766 (100 μM), arachidonic acid (a RhoA/ROCK activator, 25–100 μM) and other fatty acids that are not activators of RhoA/ROCK (25–100 μM). Gene expression was analyzed by quantitative real-time PCR, and fibulin protein levels were analyzed by western blotting and ELISA. Simvastatin induced a significant increase in mRNA and protein levels of fibulin-2 at 24 hours of incubation (p<0.05), but it did not affect fibulin-1, -4, and -5 expression. Mevalonate and GGPP were able to reverse simvastatin’s effect, while FPP did not. In addition, Y-27632, but not NSC23766, significantly increased fibulin-2 expression. Furthermore, activation of the RhoA/ROCK pathway with arachidonic acid decreased fibulin-2 mRNA. Simvastatin increased mRNA levels and protein expression of the ECM protein fibulin-2 through a RhoA and Rho-Kinase-mediated pathway. This increase could affect the composition and structure of the ECM. PMID:26207907

  13. Trifluoperazine increases fatty acid turnover in phospholipids in cultured human fibroblasts.

    PubMed

    Mazière, C; Mazière, J C; Mora, L; Auclair, M; Polonovski, J

    1988-05-01

    A 24-hr pretreatment of cultured human fibroblasts with trifluoperazine induced a marked increase in incorporation of saturated (stearic, palmitic) and unsaturated (oleic, arachidonic) fatty acids into phospholipids (1.5- to 2-fold for 5.10(-5) M trifluoperazine). Concomitantly, incorporation into cholesteryl esters was strongly inhibited (20% of control for 5.10(-5) M trifluoperazine). The drug did not change the phospholipid composition of treated cells. The effect of trifluoperazine on oleic acid incorporation into phospholipids was time-dependent and reached a maximum after a six-hr preincubation with the drug. Trifluoperazine also induced an increase in the rate of chase of oleic acid from the different phospholipid classes. In vitro preincubation of cell-free extracts with trifluoperazine resulted in activation of phospholipid acyltransferases, whereas cholesterol acyltransferase activity was decreased. The rapid effect of trifluoperazine together with its effect on a cell-free system suggests a direct action of this amphiphilic drug on the acyltransferase activities, probably by modification of the structural organization of cellular membranes.

  14. Mechanism of Cytosolic Phospholipase A(2) Activation in Ghrelin Protection of Salivary Gland Acinar Cells against Ethanol Cytotoxicity.

    PubMed

    Slomiany, Bronislaw L; Slomiany, Amalia

    2010-01-01

    Ghrelin, a peptide hormone, newly identified in oral mucosal tissues, has emerged recently as an important mediator of the processes of mucosal defense. Here, we report on the mechanism of ghrelin protection against ethanol cytotoxicity in rat sublingual salivary gland cells. The protective effect of ghrelin was associated with the increase in NO and PGE2, and upregulation in cytosolic phospholipase A(2) (cPLA(2)) activity and arachidonic acid (AA) release. The loss in countering effect of ghrelin occurred with cNOS inhibitor, L-NAME, as well as indomethacin and COX-1 inhibitor, SC-560, while COX-2 inhibitor, NS-398, and iNOS inhibitor, 1400W, had no effect. The effect of L-NAME was reflected in the inhibition of ghrelin-induced cell capacity for NO production, cPLA(2) activation and PGE2 generation, whereas indomethacin caused only the inhibition in PGE2. Moreover, the ghrelin-induced up-regulation in AA release was reflected in the cPLA(2) phosphorylation and S-nitrosylation. Inhibition in ghrelin-induced S-nitrosylation was attained with L-NAME, whereas the ERK inhibitor, PD98059, caused the blockage in cPLA(2) protein phosphorylation as well as S-nitrosylation. Thus, ghrelin protection of salivary gland cells against ethanol involves cNOS-derived NO induction of cPLA(2) activation through S-nitrosylation for the increase in AA release at the site of COX-1 action for PGE2 synthesis.

  15. Aldosterone increases kidney tubule cell oxidants through calcium-mediated activation of NADPH oxidase and nitric oxide synthase.

    PubMed

    Queisser, Nina; Schupp, Nicole; Stopper, Helga; Schinzel, Reinhard; Oteiza, Patricia I

    2011-12-01

    Chronic hyperaldosteronism has been associated with an increased cancer risk. We recently showed that aldosterone causes an increase in cell oxidants, DNA damage, and NF-κB activation. This study investigated the mechanisms underlying aldosterone-induced increase in cell oxidants in kidney tubule cells. Aldosterone caused an increase in both reactive oxygen and reactive nitrogen (RNS) species. The involvement of the activation of NADPH oxidase in the increase in cellular oxidants was demonstrated by the inhibitory action of the NADPH oxidase inhibitors DPI, apocynin, and VAS2870 and by the migration of the p47 subunit to the membrane. NADPH oxidase activation occurred as a consequence of an increase in cellular calcium levels and was mediated by protein kinase C. The prevention of RNS increase by BAPTA-AM, W-7, and L-NAME indicates a calcium-calmodulin activation of NOS. A similar pattern of effects of the NADPH oxidase and NOS inhibitors was observed for aldosterone-induced DNA damage and NF-κB activation, both central to the pathogenesis of chronic aldosteronism. In summary, this paper demonstrates that aldosterone, via the mineralocorticoid receptor, causes an increase in kidney cell oxidants, DNA damage, and NF-κB activation through a calcium-mediated activation of NADPH oxidase and NOS. Therapies targeting calcium, NOS, and NADPH oxidase could prevent the adverse effects of hyperaldosteronism on kidney function as well as its potential oncogenic action.

  16. Increased intracranial pressure

    MedlinePlus

    ... rupture and subarachnoid hemorrhage Brain tumor Encephalitis Head injury Hydrocephalus (increased fluid around the brain) Hypertensive brain hemorrhage Intraventricular hemorrhage Meningitis Subdural hematoma Status epilepticus Stroke

  17. Increased cavernosal relaxation by Phoneutria nigriventer toxin, PnTx2-6, via activation at NO/cGMP signaling

    PubMed Central

    Nunes, K.P.; Wynne, B.M.; Cordeiro, M.N.; Borges, M.H.; Richardson, M; Leite, R.; DeLima, M.E.; Webb, R. C

    2011-01-01

    Erectile dysfunction mechanisms in diabetic patients are multifactorial and often lead to resistance to current therapy. Animal toxins have been used as pharmacological tools to study penile erection. Human accidents involving the venom of Phoneutria nigriventer spider are characterized by priapism. We hypothesize that PnTx2-6 potentiates cavernosal relaxation in diabetic mice by increasing cGMP. This effect is nNOS dependent. Cavernosal strips were contracted with phenylephrine (10−5 M) and relaxed by electrical field stimulation (EFS, 20V, 1–32 Hz) in the presence or absence of PnTx2-6 (10−8 M).Cavernosal strips from nNOS and eNOS knocaut (KO) mice, besides nNOS inhibitor (10−5M), were used to evaluate the role of this enzyme in the potentiation effect evoked by PnTx2-6. Tissue cGMP levels were determined after stimulation with PnTx2-6 in presence or absence of L-NAME (10−4M) and ω-conotoxin GVIA (10−6M), an N-type calcium channel inhibitor. Results showed PnTx2-6 enhanced cavernosal relaxation in diabetic mice (65%) and eNOS KO mice, but not in nNOS KO mice. The toxin effect in the cavernosal relaxation was abolished by nNOS inhibitor. cGMP levels are increased by PnTx2-6, however L-NAME abolished this enhancement as well as ω-conotoxin GVIA. We conclude PnTx2-6 facilitates penile relaxation in diabetic mice through a mechanism dependent on nNOS, probably via increasing NO/cGMP production. PMID:21975567

  18. Increasing hygiene productivity.

    PubMed

    Levin, Roger P

    2003-03-01

    Dentists have many opportunities to expand the role of dental hygienists and provide patients with better oral health care, while increasing production and profits. But the proper business systems and verbal skills need to be incorporated. You must train hygienists to do all they can do for every patient. Begin with one service and add others, as the hygienists becomes familiar with each one. Set a goal of a 15% increase in production per year for the hygiene department. Clinicians using these strategies have experienced as much as a 100% to 200% increase in hygiene revenue during the first year of incorporating these services. An added benefit is that these dentists often see a substantial increase in dental treatment diagnosis and case acceptance. An effective and efficient hygiene department will often identify and help secure more than 50% of a doctor's production.

  19. Increasing productivity: Another approach

    SciTech Connect

    Norton, F.J.

    1996-06-10

    An engineering information (EI) and information technology (IT) organization that must improve its productivity should work to further its business goals. This paper explores a comprehensive model for increasing EI/IT productivity by supporting organizational objectives.

  20. Increasing Public Library Productivity.

    ERIC Educational Resources Information Center

    Samuelson, Howard

    1981-01-01

    Suggests ways of improving productivity for public libraries faced with increased accountability, dwindling revenues, and continuing inflation. Techniques described include work simplification, work analysis, improved management, and employee motivation. (RAA)

  1. Increases in Problem Drinking

    MedlinePlus

    ... review our exit disclaimer . Subscribe Increases in Problem Drinking Alcohol use disorder is becoming more common, a ... the need to better educate people about problem drinking and its treatment. Alcohol use disorder, or AUD, ...

  2. NOS inhibition increases bubble formation and reduces survival in sedentary but not exercised rats.

    PubMed

    Wisløff, Ulrik; Richardson, Russell S; Brubakk, Alf O

    2003-01-15

    Previously we have shown that chronic as well as a single bout of exercise 20 h prior to a simulated dive protects rats from severe decompression illness (DCI) and death. However, the mechanism behind this protection is still not known. The present study determines the effect of inhibiting nitric oxide synthase (NOS) on bubble formation in acutely exercised and sedentary rats exposed to hyperbaric pressure. A total of 45 adult female Sprague-Dawley rats (270-320 g) were randomly assigned into exercise or sedentary control groups, with and without NOS inhibition, using L-NAME (0.05 or 1 mg ml(-1)) (a nonselective NOS inhibitor). Exercising rats ran intervals on a treadmill for 1.5 h, 20 h prior to the simulated dive. Intervals alternated between 8 min at 85-90 % of maximal oxygen uptake, and 2 min at 50-60 %. Rats were compressed (simulated dive) in a pressure chamber, at a rate of 200 kPa min(-1) to a pressure of 700 kPa, and maintained for 45 min breathing air. At the end of the exposure period, rats were decompressed linearly to the "surface" (100 kPa) at a rate of 50 kPa min(-1). Immediately after reaching the surface the animals were anaesthetised and the right ventricle was insonated using ultrasound. The study demonstrated that sedentary rats weighing more than 300 g produced a large amount of bubbles, while those weighing less than 300 g produced few bubbles and most survived the protocol. Prior exercise reduced bubble formation and increased survival in rats weighing more than 300 g, confirming the results from the previous study. During NOS inhibition, the simulated dive induced significantly more bubbles in all sedentary rats weighing less than 300 g. However, this effect could be attenuated by a single bout of exercise 20 h before exposure. The present study demonstrates two previously unreported findings: that administration of L-NAME allows substantial bubble formation and decreased survival in sedentary rats, and that a single bout of exercise

  3. Hypoxia stimulates prostacyclin synthesis in newborn pulmonary artery endothelium by increasing cyclooxygenase-1 protein.

    PubMed

    North, A J; Brannon, T S; Wells, L B; Campbell, W B; Shaul, P W

    1994-07-01

    In newborn lambs, pulmonary prostacyclin (PGI2) production increases acutely in response to low oxygen. We tested the hypothesis that decreased oxygenation directly stimulates PGI2 synthesis in arterial segments and cultured endothelial cells from newborn lamb intrapulmonary arteries. In segments studied at PO2 of 680 mm Hg, the synthesis of PGI2 exceeded prostaglandin E2 (PGE2) by 73%. Endothelium removal lowered PGI2 by 77% and PGE2 by 66%. At low oxygen tension (PO2, 40 mm Hg), PGI2 and PGE2 synthesis rose by 96% and 102%, respectively. Similarly, in endothelial cells studied at PO2 of 680 mm Hg, the synthesis of PGI2 exceeded PGE2 by 50%, and at low oxygen tension both PGI2 and PGE2 increased (89% and 64%, respectively). Endothelial cell PGI2 synthesis maximally stimulated by bradykinin, A23187, or arachidonic acid was also increased at low PO2 by 50%, 66%, and 48%, respectively. PGE2 synthesis was similarly altered, increasing by 33%, 37%, and 41%, respectively. In contrast, lowering oxygen had minimal effect on PGI2 and PGE2 synthesis with exogenous PGH2, which is the product of cyclooxygenase. Immunoblot analyses revealed that there was a 2.6-fold greater abundance of cyclooxygenase-1 protein at PO2 of 40 versus 680 mm Hg, and the increase at lower oxygen tension was inhibited by cycloheximide. The cyclooxygenase-2 isoform was not detected. Thus, attenuated oxygenation directly stimulates PGI2 and PGE2 synthesis in intrapulmonary arterial segments and endothelial cells from newborn lambs. This process is due to enhanced cyclooxygenase activity related to increased abundance of the cyclooxygenase-1 protein, and this effect may be due to increased synthesis of the enzyme protein.

  4. Flaxseed oil increases aortic reactivity to phenylephrine through reactive oxygen species and the cyclooxygenase-2 pathway in rats

    PubMed Central

    2014-01-01

    Background Flaxseed oil has the highest concentration of omega-3 α-linolenic acid, which has been associated with cardiovascular benefit. However, the mechanism underlying the vascular effects induced through flaxseed oil is not well known. Thus, in the present study, we investigated the effects of flaxseed oil on vascular function in isolated rat aortic rings. Methods Wistar rats were treated daily with flaxseed oil or a control (mineral oil) intramuscular (i.m.) for fifteen days. Isolated aortic segments were used to evaluate cyclooxygenase-2 (COX-2) protein expression, superoxide anion levels and vascular reactivity experiments. Results Flaxseed oil treatment increased the vasoconstrictor response of aortic rings to phenylephrine. Endothelium removal increased the response to phenylephrine in aortic segments isolated from both groups, but the effect was smaller in the treated group. L-NAME incubation similarly increased the phenylephrine response in segments from both groups. The TXA2 synthase inhibitor furegrelate, the selective COX-2 inhibitor NS 398, the TP receptor antagonist SQ 29.548, the reactive oxygen species (ROS) scavenger apocynin, the superoxide anion scavengers tiron and the phospholipase A2 inhibitor dexamethasone partially reversed the flaxseed oil-induced increase in reactivity to phenylephrine. Conclusions These findings suggest that flaxseed oil treatment increased vascular reactivity to phenylephrine through an increase in ROS production and COX-2-derived TXA2 production. The results obtained in the present study provide new insight into the effects of flaxseed oil treatment (i.m.) on vascular function. PMID:24993607

  5. Seismic waves increase permeability.

    PubMed

    Elkhoury, Jean E; Brodsky, Emily E; Agnew, Duncan C

    2006-06-29

    Earthquakes have been observed to affect hydrological systems in a variety of ways--water well levels can change dramatically, streams can become fuller and spring discharges can increase at the time of earthquakes. Distant earthquakes may even increase the permeability in faults. Most of these hydrological observations can be explained by some form of permeability increase. Here we use the response of water well levels to solid Earth tides to measure permeability over a 20-year period. At the time of each of seven earthquakes in Southern California, we observe transient changes of up to 24 degrees in the phase of the water level response to the dilatational volumetric strain of the semidiurnal tidal components of wells at the Piñon Flat Observatory in Southern California. After the earthquakes, the phase gradually returns to the background value at a rate of less than 0.1 degrees per day. We use a model of axisymmetric flow driven by an imposed head oscillation through a single, laterally extensive, confined, homogeneous and isotropic aquifer to relate the phase response to aquifer properties. We interpret the changes in phase response as due to changes in permeability. At the time of the earthquakes, the permeability at the site increases by a factor as high as three. The permeability increase depends roughly linearly on the amplitude of seismic-wave peak ground velocity in the range of 0.21-2.1 cm s(-1). Such permeability increases are of interest to hydrologists and oil reservoir engineers as they affect fluid flow and might determine long-term evolution of hydrological and oil-bearing systems. They may also be interesting to seismologists, as the resulting pore pressure changes can affect earthquakes by changing normal stresses on faults.

  6. Increased global financings

    SciTech Connect

    Anderson, J.

    1994-10-01

    The results of a financial rankings survey for the first half of 1994 show increased financial activity over the second half of 1993. More than $10.5 billion is reported by developers and financial firms for 62 transactions during 1994`s first six months.

  7. Productivity increases in science

    SciTech Connect

    Danko, J.E.; Young, J.K.; Molton, P.M.; Dirks, J.A.

    1993-02-01

    The study quantifies the impact on the cost of experimentation of synergistic advancements in instrumentation, theory, and computation over the last two decades. The study finds that the productivity of experimental investigation (experimental results/$) is increasing as science is transformed from a linear, isolated approach to a hierarchical, multidisciplinary approach. Developments such as massively parallel processors coupled with instrumental systems with multiple probes and diverse data analysis capabilities will further this transformation and increase the productivity of scientific studies. The complexities and scale of today`s scientific challenges are much greater than in the past, however, so that the costs of research are increasing. Even though science is much more productive in terms of the experimental results, the challenges facing scientific investigators are increasing at an even faster pace. New approaches to infrastructure investments must capitalize on the changing dynamics of research and allow the scientific community to maximize gains in productivity so that complex problems can be attacked cost-effectively. Research strategies that include user facilities and coordinated experimental, computational, and theoretical research are needed.

  8. Productivity increases in science

    SciTech Connect

    Danko, J.E.; Young, J.K.; Molton, P.M.; Dirks, J.A.

    1993-02-01

    The study quantifies the impact on the cost of experimentation of synergistic advancements in instrumentation, theory, and computation over the last two decades. The study finds that the productivity of experimental investigation (experimental results/$) is increasing as science is transformed from a linear, isolated approach to a hierarchical, multidisciplinary approach. Developments such as massively parallel processors coupled with instrumental systems with multiple probes and diverse data analysis capabilities will further this transformation and increase the productivity of scientific studies. The complexities and scale of today's scientific challenges are much greater than in the past, however, so that the costs of research are increasing. Even though science is much more productive in terms of the experimental results, the challenges facing scientific investigators are increasing at an even faster pace. New approaches to infrastructure investments must capitalize on the changing dynamics of research and allow the scientific community to maximize gains in productivity so that complex problems can be attacked cost-effectively. Research strategies that include user facilities and coordinated experimental, computational, and theoretical research are needed.

  9. Prolonged niacin treatment leads to increased adipose tissue PUFA synthesis and anti-inflammatory lipid and oxylipin plasma profile.

    PubMed

    Heemskerk, Mattijs M; Dharuri, Harish K; van den Berg, Sjoerd A A; Jónasdóttir, Hulda S; Kloos, Dick-Paul; Giera, Martin; van Dijk, Ko Willems; van Harmelen, Vanessa

    2014-12-01

    Prolonged niacin treatment elicits beneficial effects on the plasma lipid and lipoprotein profile that is associated with a protective CVD risk profile. Acute niacin treatment inhibits nonesterified fatty acid release from adipocytes and stimulates prostaglandin release from skin Langerhans cells, but the acute effects diminish upon prolonged treatment, while the beneficial effects remain. To gain insight in the prolonged effects of niacin on lipid metabolism in adipocytes, we used a mouse model with a human-like lipoprotein metabolism and drug response [female APOE*3-Leiden.CETP (apoE3 Leiden cholesteryl ester transfer protein) mice] treated with and without niacin for 15 weeks. The gene expression profile of gonadal white adipose tissue (gWAT) from niacin-treated mice showed an upregulation of the "biosynthesis of unsaturated fatty acids" pathway, which was corroborated by quantitative PCR and analysis of the FA ratios in gWAT. Also, adipocytes from niacin-treated mice secreted more of the PUFA DHA ex vivo. This resulted in an increased DHA/arachidonic acid (AA) ratio in the adipocyte FA secretion profile and in plasma of niacin-treated mice. Interestingly, the DHA metabolite 19,20-dihydroxy docosapentaenoic acid (19,20-diHDPA) was increased in plasma of niacin-treated mice. Both an increased DHA/AA ratio and increased 19,20-diHDPA are indicative for an anti-inflammatory profile and may indirectly contribute to the atheroprotective lipid and lipoprotein profile associated with prolonged niacin treatment.

  10. Designer drilling increases recovery

    SciTech Connect

    Eck-Olsen, J.; Drevdal, K.E.

    1995-04-01

    Implementation of a new designer-well profile has resulted in increased recovery and production rates. The geologically complex Gullfaks field, located in the Norwegian sector of the North Sea, required a new type of well profile to increase total recovery and production rates from Gullfaks A, B and C platforms. Advances in steerable technology and directional drilling performance enabled a 3-D horizontal, extended-reach well profile, now designated as a designer well, to penetrate multiple targets. This article presents the concept, implementation and conclusions drawn from designer well application. Gullfaks field, in Norwegian North Sea Block 34/10, is the first license ever run by a fully Norwegian joint venture corporation. The license group consists of Statoil (operator), Norsk Hydro and Saga Petroleum. The field currently produces more than 535,000 bopd from three main Jurassic reservoirs.

  11. Revamps increase efficiency

    SciTech Connect

    Marschner, F.; Moertel, H.G.

    1986-01-01

    In many cases, idle capacities throughout the work and lack of financing capital forbid the construction of new chemical plants that are more profitable and reflect the latest state-of-the-art. On the other hand, the glut of cheap raw materials over the past 20 years led to the construction of numerous plants according to the motto, ''make it cheap-energy consumption is of secondary importance.'' Such projects included, above all, hydrogen plants based on natural gas and plants to produce syngases for methanol, ammonia and oxo alcohols. As raw materials are becoming scarcer almost everywhere in the work and raw material prices keep rising, taking such plants out of service in many instances can be avoided only by increasing their efficiency, sometimes by increasing their capacity (debottlenecking) or by revamping them to use cheaper feedstocks.

  12. High population increase rates.

    PubMed

    1991-09-01

    In addition to its economic and ethnic difficulties, the USSR faces several pressing demographic problems, including high population increase rates in several of its constituent republics. It has now become clear that although the country's rigid centralized planning succeeded in covering the basic needs of people, it did not lead to welfare growth. Since the 1970s, the Soviet economy has remained sluggish, which as led to increase in the death and birth rates. Furthermore, the ideology that held that demography could be entirely controlled by the country's political and economic system is contradicted by current Soviet reality, which shows that religion and ethnicity also play a significant role in demographic dynamics. Currently, Soviet republics fall under 2 categories--areas with high or low natural population increase rates. Republics with low rates consist of Christian populations (Armenia, Moldavia, Georgia, Byelorussia, Russia, Lithuania, Estonia, Latvia, Ukraine), while republics with high rates are Muslim (Tadzhikistan, Uzbekistan, Turkmenistan, Kirgizia, Azerbaijan Kazakhstan). The later group has natural increase rates as high as 3.3%. Although the USSR as a whole is not considered a developing country, the later group of republics fit the description of the UNFPA's priority list. Another serious demographic issue facing the USSR is its extremely high rate of abortion. This is especially true in the republics of low birth rates, where up to 60% of all pregnancies are terminated by induced abortions. Up to 1/5 of the USSR's annual health care budget is spent on clinical abortions -- money which could be better spent on the production of contraceptives. Along with the recent political and economic changes, the USSR is now eager to deal with its demographic problems. PMID:12284289

  13. Increase in family allowances.

    PubMed

    1989-01-01

    In July 1989 the family allowance structure in Australia was changed from a 4-rate to a 2-rate structure. The new rates were increased to $A9 a week for the 1st 3 children and $A12 for each additional child. The Family Allowance Supplment rate for children 13-15 years old was raised from $A31 to $A34.10/week. PMID:12344544

  14. Increasing student success

    NASA Astrophysics Data System (ADS)

    Stewart, Gay; Stewart, John

    2013-03-01

    A more scientifically literate society benefits all STEM disciplines, as well as society as a whole. It is best realized by better serving all undergraduate STEM students. In better-serving all students, a physics department also benefits. The University of Arkansas, Fayetteville physics department has seen a drastic change in number of majors, the number of students active in research and the number of graduates pursuing graduate work, while also increasing the number of majors who decide to teach. Prior to our involvement with the Physics Teacher Education Coalition, graduation rates had increased by more than a factor of 4 in 4 years. After the increased efforts when we became a part of PhysTEC (http://PhysTEC.org) our graduation numbers doubled again. Specific attention to class policy to impact student learning in our introductory courses and strong preparation of the graduate teaching assistants, and quality advising were our primary areas of emphasis. What worked to build these numbers and strengthen these resources at Arkansas will be discussed. This work was supported in part by the National Science Foundation and through the Physics Teacher Education Coalition.

  15. Condom use increasing.

    PubMed

    Finger, W R

    1998-01-01

    Condom use is central to the prevention of AIDS among people at risk for contracting HIV. As such, condom use is increasing dramatically even though many men say that they do not like using them. Condom sales through social marketing campaigns have increased dramatically in some countries, where tens of millions of condoms are sold annually. For example, during the period 1991-96, annual social marketing sales increased about five-fold in Ethiopia to 21 million, and nine-fold in Brazil to 27 million. These sales reflect the success of condom social marketing campaigns in making condoms accessible and largely affordable. There is also a greater general awareness of AIDS than there used to be, and communication campaigns have shown that condoms are an effective solution. More condoms still need to be used in the ongoing struggle against HIV/AIDS. The author discusses the factors which affect the limited acceptance of condoms, condom use outside of marriage, social marketing, and family planning programs. PMID:12293530

  16. Alarming increase in refugees.

    PubMed

    1992-01-01

    Over the past decade and half there has been an alarming worldwide increase in refugees. The total rose form 2.8 million in 1976 to 8.2 million in 1980, to 17.3 million in 1990. Africa's refugees rose from 1.2 million in 1976 to 5.6 million in 1990. Asia's increase over this period was much more rapid--from a mere 180,000 to 8 million. In the Americas the numbers more than trebled, from 770,000 to 2.7 million. Europe was the smallest increase, from 570,000 to 894,000. International law defines a refugee as someone outside of their own country, who has a well-founded fear of persecution because of their political or religious beliefs or ethnic origin, and who cannot turn to their own country for protection. Most refugees are genuine by this definition. The increase reflects, in part, fallout from the cold war. Ethiopia, Mozambique and Angola accounted for almost 1/2 of Africa's refugees; Afghanistan alone for 3/4 of Asia's total. They fled, for the most part, from 1 poor country into another, where they added to shortages of land and fuelwood, and intensified environmental pressure. Malawi, 1 of the poorest countries in the world, is sheltering perhaps as many as 750,000 refugees from the war in Mozambique. But among these refugees--especially among those who turned to the rich countries for asylum--were an increasing number of people who were not suffering political persecution. Driven out of their homes by the collapse of their environment or economic despair, and ready to take any means to get across borders, they are a new category: economic and environmental refugees. The most spectacular attempts hit the television screens: the Vietnamese boat people, ships festooned with Albanians. Behind the headlines there was a growing tide of asylum seekers. The numbers rose 10-fold in Germany from 1983 to 1990. In Switzerland they multiplied by 4 times. In Europe, as a whole, they grew from 71,000 in 1983 to an estimated 550,000 in 1990. In 1990 the numbers threatened to

  17. Dietary n-6 polyunsaturated fatty acid deprivation increases docosahexaenoic acid metabolism in rat brain.

    PubMed

    Igarashi, Miki; Kim, Hyung-Wook; Chang, Lisa; Ma, Kaizong; Rapoport, Stanley I

    2012-03-01

    Dietary n-6 polyunsaturated fatty acid (PUFA) deprivation in rodents reduces brain arachidonic acid (20:4n-6) concentration and 20:4n-6-preferring cytosolic phospholipase A(2) (cPLA(2) -IVA) and cyclooxygenase (COX)-2 expression, while increasing brain docosahexaenoic acid (DHA, 22:6n-3) concentration and DHA-selective calcium-independent phospholipase A(2) (iPLA(2) )-VIA expression. We hypothesized that these changes are accompanied by up-regulated brain DHA metabolic rates. Using a fatty acid model, brain DHA concentrations and kinetics were measured in unanesthetized male rats fed, for 15 weeks post-weaning, an n-6 PUFA 'adequate' (31.4 wt% linoleic acid) or 'deficient' (2.7 wt% linoleic acid) diet, each lacking 20:4n-6 and DHA. [1-(14) C]DHA was infused intravenously, arterial blood was sampled, and the brain was microwaved at 5 min and analyzed. Rats fed the n-6 PUFA deficient compared with adequate diet had significantly reduced n-6 PUFA concentrations in brain phospholipids but increased eicosapentaenoic acid (EPA, 20:5n-3), docosapentaenoic acid n-3 (DPAn-3, 22:5n-3), and DHA (by 9.4%) concentrations, particularly in ethanolamine glycerophospholipid (EtnGpl). Incorporation rates of unesterified DHA from plasma, which represent DHA metabolic loss from brain, were increased 45% in brain phospholipids, as was DHA turnover. Increased DHA metabolism following dietary n-6 PUFA deprivation may increase brain concentrations of antiinflammatory DHA metabolites, which with a reduced brain n-6 PUFA content, likely promotes neuroprotection and alters neurotransmission.

  18. Phospholipase D1 increases Bcl-2 expression during neuronal differentiation of rat neural stem cells.

    PubMed

    Park, Shin-Young; Ma, Weina; Yoon, Sung Nyo; Kang, Min Jeong; Han, Joong-Soo

    2015-01-01

    We studied the possible role of phospholipase D1 (PLD1) in the neuronal differentiation, including neurite formation of neural stem cells. PLD1 protein and PLD activity increased during neuronal differentiation. Bcl-2 also increased. Downregulation of PLD1 by transfection with PLD1 siRNA or a dominant-negative form of PLD1 (DN-PLD1) inhibited both neurite outgrowth and Bcl-2 expression. PLD activity was dramatically reduced by a PLCγ (phospholipase Cγ) inhibitor (U73122), a Ca(2+)chelator (BAPTA-AM), and a PKCα (protein kinase Cα) inhibitor (RO320432). Furthermore, treatment with arachidonic acid (AA) which is generated by the action of PLA2 (phospholipase A2) on phosphatidic acid (a PLD1 product), increased the phosphorylation of p38 MAPK and CREB, as well as Bcl-2 expression, indicating that PLA2 is involved in the differentiation process resulting from PLD1 activation. PGE2 (prostaglandin E2), a cyclooxygenase product of AA, also increased during neuronal differentiation. Moreover, treatment with PGE2 increased the phosphorylation of p38 MAPK and CREB, as well as Bcl-2 expression, and this effect was inhibited by a PKA inhibitor (Rp-cAMP). As expected, inhibition of p38 MAPK resulted in loss of CREB activity, and when CREB activity was blocked with CREB siRNA, Bcl-2 production also decreased. We also showed that the EP4 receptor was required for the PKA/p38MAPK/CREB/Bcl-2 pathway. Taken together, these observations indicate that PLD1 is activated by PLCγ/PKCα signaling and stimulate Bcl-2 expression through PLA2/Cox2/EP4/PKA/p38MAPK/CREB during neuronal differentiation of rat neural stem cells.

  19. Omeprazole increases the efficacy of a soluble epoxide hydrolase inhibitor in a PGE₂ induced pain model.

    PubMed

    Goswami, Sumanta Kumar; Inceoglu, Bora; Yang, Jun; Wan, Debin; Kodani, Sean D; da Silva, Carlos Antonio Trindade; Morisseau, Christophe; Hammock, Bruce D

    2015-12-15

    Epoxyeicosatrienoic acids (EETs) are potent endogenous analgesic metabolites produced from arachidonic acid by cytochrome P450s (P450s). Metabolism of EETs by soluble epoxide hydrolase (sEH) reduces their activity, while their stabilization by sEH inhibition decreases both inflammatory and neuropathic pain. Here, we tested the complementary hypothesis that increasing the level of EETs through induction of P450s by omeprazole (OME), can influence pain related signaling by itself, and potentiate the anti-hyperalgesic effect of sEH inhibitor. Rats were treated with OME (100mg/kg/day, p.o., 7 days), sEH inhibitor TPPU (3mg/kg/day, p.o.) and OME (100mg/kg/day, p.o., 7 days)+TPPU (3mg/kg/day, p.o., last 3 days of OME dose) dissolved in vehicle PEG400, and their effect on hyperalgesia (increased sensitivity to pain) induced by PGE2 was monitored. While OME treatment by itself exhibited variable effects on PGE2 induced hyperalgesia, it strongly potentiated the effect of TPPU in the same assay. The significant decrease in pain with OME+TPPU treatment correlated with the increased levels of EETs in plasma and increased activities of P450 1A1 and P450 1A2 in liver microsomes. The results show that reducing catabolism of EETs with a sEH inhibitor yielded a stronger analgesic effect than increasing generation of EETs by OME, and combination of both yielded the strongest pain reducing effect under the condition of this study. PMID:26522832

  20. Resveratrol increases nitric oxide production in the rat thick ascending limb via Ca2+/calmodulin.

    PubMed

    Gonzalez-Vicente, Agustin; Cabral, Pablo D; Garvin, Jeffrey L

    2014-01-01

    The thick ascending limb of the loop of Henle reabsorbs 30% of the NaCl filtered through the glomerulus. Nitric oxide (NO) produced by NO synthase 3 (NOS3) inhibits NaCl absorption by this segment. Resveratrol, a polyphenol, has beneficial cardiovascular and renal effects, many of which are mediated by NO. Resveratrol increases intracellular Ca2+ (Cai) and AMP kinase (AMPK) and NAD-dependent deacetylase sirtuin1 (SIRT1) activities, all of which could activate NO production. We hypothesized that resveratrol stimulates NO production by thick ascending limbs via a Ca2+/calmodulin-dependent mechanism. To test this, the effect of resveratrol on NO bioavailability was measured in thick ascending limb suspensions. Cai was measured in single perfused thick ascending limbs. SIRT1 activity and expression were measured in thick ascending limb lysates. Resveratrol (100 µM) increased NO bioavailability in thick ascending limb suspensions by 1.3±0.2 AFU/mg/min (p<0.03). The NOS inhibitor L-NAME blunted resveratrol-stimulated NO bioavailability by 96±11% (p<0.03). The superoxide scavenger tempol had no effect. Resveratrol elevated Cai from 48±7 to 135±24 nM (p<0.01) in single tubules. In Ca2+-free media, the resveratrol-induced increase in NO was blunted by 60±20% (p<0.05) and the rise in Cai reduced by 80%. Calmodulin inhibition prevented the resveratrol-induced increase in NO (p<0.002). AMPK inhibition had no effect. Resveratrol did not increase SIRT1 activity. We conclude that resveratrol increases NO production in thick ascending limbs via a Ca2+/calmodulin dependent mechanism, and SIRT1 and AMPK do not participate. Resveratrol-stimulated NO production in thick ascending limbs may account for part of its beneficial effects.

  1. Resveratrol increases nitric oxide production in the rat thick ascending limb via Ca2+/calmodulin.

    PubMed

    Gonzalez-Vicente, Agustin; Cabral, Pablo D; Garvin, Jeffrey L

    2014-01-01

    The thick ascending limb of the loop of Henle reabsorbs 30% of the NaCl filtered through the glomerulus. Nitric oxide (NO) produced by NO synthase 3 (NOS3) inhibits NaCl absorption by this segment. Resveratrol, a polyphenol, has beneficial cardiovascular and renal effects, many of which are mediated by NO. Resveratrol increases intracellular Ca2+ (Cai) and AMP kinase (AMPK) and NAD-dependent deacetylase sirtuin1 (SIRT1) activities, all of which could activate NO production. We hypothesized that resveratrol stimulates NO production by thick ascending limbs via a Ca2+/calmodulin-dependent mechanism. To test this, the effect of resveratrol on NO bioavailability was measured in thick ascending limb suspensions. Cai was measured in single perfused thick ascending limbs. SIRT1 activity and expression were measured in thick ascending limb lysates. Resveratrol (100 µM) increased NO bioavailability in thick ascending limb suspensions by 1.3±0.2 AFU/mg/min (p<0.03). The NOS inhibitor L-NAME blunted resveratrol-stimulated NO bioavailability by 96±11% (p<0.03). The superoxide scavenger tempol had no effect. Resveratrol elevated Cai from 48±7 to 135±24 nM (p<0.01) in single tubules. In Ca2+-free media, the resveratrol-induced increase in NO was blunted by 60±20% (p<0.05) and the rise in Cai reduced by 80%. Calmodulin inhibition prevented the resveratrol-induced increase in NO (p<0.002). AMPK inhibition had no effect. Resveratrol did not increase SIRT1 activity. We conclude that resveratrol increases NO production in thick ascending limbs via a Ca2+/calmodulin dependent mechanism, and SIRT1 and AMPK do not participate. Resveratrol-stimulated NO production in thick ascending limbs may account for part of its beneficial effects. PMID:25314136

  2. Ovariectomy Increases the Participation of Hyperpolarizing Mechanisms in the Relaxation of Rat Aorta

    PubMed Central

    Sagredo, Ana; del Campo, Lara; Martorell, Aina; Navarro, Rocío; Martín, María C.; Blanco-Rivero, Javier; Ferrer, Mercedes

    2013-01-01

    This study examines the downstream NO release pathway and the contribution of different vasodilator mediators in the acetylcholine-induced response in rat aorta 5-months after the loss of ovarian function. Aortic segments from ovariectomized and control female Sprague-Dawley rats were used to measure: the levels of superoxide anion, the superoxide dismutases (SODs) activity, the cGMP formation, the cGMP-dependent protein kinase (PKG) activity and the involvement of NO, cGMP, hydrogen peroxide and hyperpolarizing mechanisms in the ACh-induced relaxation. The results showed that ovariectomy did not alter ACh-induced relaxation; incubation with L-NAME, a NO synthase inhibitor, decreased the ACh-induced response to a lesser extent in aorta from ovariectomized than from control rats, while ODQ, a guanylate cyclase inhibitor, decreased that response to a similar extent; the blockade of hyperpolarizing mechanisms, by precontracting arteries with KCl, decreased the ACh-induced response to a greater extent in aortas from ovariectomized than those from control rats; catalase, that decomposes hydrogen peroxide, decreased the ACh-induced response only in aorta from ovariectomized rats. In addition, ovariectomy increased superoxide anion levels and SODs activity, decreased cGMP formation and increased PKG activity. Despite the increased superoxide anion and decreased cGMP in aorta from ovariectomized rats, ACh-induced relaxation is maintained by the existence of hyperpolarizing mechanisms in which hydrogen peroxide participates. The greater contribution of hydrogen peroxide in ACh-induced relaxation is due to increased SOD activity, in an attempt to compensate for increased superoxide anion formation. Increased PKG activity could represent a redundant mechanism to ensure vasodilator function in the aorta of ovariectomized rats. PMID:24058477

  3. Increasing Childhood Influenza Vaccination

    PubMed Central

    Nowalk, Mary Patricia; Lin, Chyongchiou J.; Hannibal, Kristin; Reis, Evelyn C.; Gallik, Gregory; Moehling, Krissy K.; Huang, Hsin-Hui; Allred, Norma J.; Wolfson, David H.; Zimmerman, Richard K.

    2014-01-01

    Background Since the 2008 inception of universal childhood influenza vaccination, national rates have risen more dramatically among younger children than older children and reported rates across racial/ethnic groups are inconsistent. Interventions may be needed to address age and racial disparities to achieve the recommended childhood influenza vaccination target of 70%. Purpose To evaluate an intervention to increase childhood influenza vaccination across age and racial groups. Methods In 2011–2012, 20 primary care practices treating children were randomly assigned to Intervention and Control arms of a cluster randomized controlled trial to increase childhood influenza vaccination uptake using a toolkit and other strategies including early delivery of donated vaccine, in-service staff meetings, and publicity. Results The average vaccination differences from pre-intervention to the intervention year were significantly larger in the Intervention arm (n=10 practices) than the Control arm (n=10 practices), for children aged 2–8 years (10.2 percentage points (pct pts) Intervention vs 3.6 pct pts Control) and 9–18 years (11.1 pct pts Intervention vs 4.3 pct pts Control, p<0.05), for non-white children (16.7 pct pts Intervention vs 4.6 pct pts Control, p<0.001), and overall (9.9 pct pts Intervention vs 4.2 pct pts Control, p<0.01). In multi-level modeling that accounted for person- and practice-level variables and the interactions among age, race and intervention, the likelihood of vaccination increased with younger age group (6–23 months), white race, commercial insurance, the practice’s pre-intervention vaccination rate, and being in the Intervention arm. Estimates of the interaction terms indicated that the intervention increased the likelihood of vaccination for non-white children in all age groups and white children aged 9–18 years. Conclusions A multi-strategy intervention that includes a practice improvement toolkit can significantly improve influenza

  4. Core Noise - Increasing Importance

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.

    2011-01-01

    This presentation is a technical summary of and outlook for NASA-internal and NASA-sponsored external research on core (combustor and turbine) noise funded by the Fundamental Aeronautics Program Subsonic Fixed Wing (SFW) Project. Sections of the presentation cover: the SFW system-level noise metrics for the 2015, 2020, and 2025 timeframes; turbofan design trends and their aeroacoustic implications; the emerging importance of core noise and its relevance to the SFW Reduced-Perceived-Noise Technical Challenge; and the current research activities in the core-noise area, with additional details given about the development of a high-fidelity combustor-noise prediction capability as well as activities supporting the development of improved reduced-order, physics-based models for combustor-noise prediction. The need for benchmark data for validation of high-fidelity and modeling work and the value of a potential future diagnostic facility for testing of core-noise-reduction concepts are indicated. The NASA Fundamental Aeronautics Program has the principal objective of overcoming today's national challenges in air transportation. The SFW Reduced-Perceived-Noise Technical Challenge aims to develop concepts and technologies to dramatically reduce the perceived aircraft noise outside of airport boundaries. This reduction of aircraft noise is critical to enabling the anticipated large increase in future air traffic. Noise generated in the jet engine core, by sources such as the compressor, combustor, and turbine, can be a significant contribution to the overall noise signature at low-power conditions, typical of approach flight. At high engine power during takeoff, jet and fan noise have traditionally dominated over core noise. However, current design trends and expected technological advances in engine-cycle design as well as noise-reduction methods are likely to reduce non-core noise even at engine-power points higher than approach. In addition, future low-emission combustor

  5. China update: HIV increasing.

    PubMed

    Gil, V E

    1993-01-01

    The HIV/AIDS case rate in China increased 117% over the period 1990-1992, from 446 to 957 HIV infections. While the majority of cases in 1990 were localized in Yunnan among minority farmers and manual laborers, infection is now found in 19 provinces, counties, and urban areas over a wider spectrum of society. The concentration of cases among IV-drug users has decreased from 83.4% to 72.6%. HIV monitoring and prevention stations have been in place in the country since 1986. The government also encouraged special zones and semiautonomous cities as well as the World Health Organization to take steps to monitor and prevent the spread of HIV. While these effort have served to augment the degree of sex education previously provided, low budgets, bureaucracy, and ambivalence have impeded control efforts. Only 1.25 million of the 1.16 billion population has been serosampled over 8 years and 100,000 fewer serosamples were taken in 1992 compared to in 1991. Neither the general population nor health workers have sufficient knowledge about HIV/AIDS to prevent its continued spread. While gay men sampled in Beijing were better informed about transmission means and risk groups, over two thirds believed they were not at risk if they avoided having sex with foreigners. Recent economic reform measures allowing large movements of population from rural to urban areas, increased disposable income available for prostitutes, and greater exposure to alternative sexual norms and behaviors through the media and music further increase the risk of HIV transmission, especially among the younger generation. To counter these risks, an AIDS hotline for information and referrals has been established in Beijing which openly reaches out to the homosexual community and fields 8-12 calls/day. Training programs for doctors, counselors, professors, and social workers have been attended by people from more than 30 provinces and regions. In addition, modest research into sexual behavior is also being

  6. Aerobic Exercise Training Prevents the Onset of Endothelial Dysfunction via Increased Nitric Oxide Bioavailability and Reduced Reactive Oxygen Species in an Experimental Model of Menopause

    PubMed Central

    Braga, Viviane A. V. N.; Couto, Gisele K.; Lazzarin, Mariana C.; Rossoni, Luciana V.; Medeiros, Alessandra

    2015-01-01

    Objective Previous studies have shown that estrogen deficiency, arising in postmenopause, promotes endothelial dysfunction. This study evaluated the effects of aerobic exercise training on endothelial dependent vasodilation of aorta in ovariectomized rats, specifically investigating the role of nitric oxide (NO) and reactive oxygen species (ROS). Methods Female Wistar rats ovariectomized (OVX – n=20) or with intact ovary (SHAM – n=20) remained sedentary (OVX and SHAM) or performed aerobic exercise training on a treadmill 5 times a week for a period of 8 weeks (OVX-TRA and SHAM-TRA). In the thoracic aorta the endothelium-dependent and –independent vasodilation was assessed by acetylcholine (ACh) and sodium nitroprusside (SNP), respectively. Certain aortic rings were incubated with L-NAME to assess the NO modulation on the ACh-induced vasodilation. The fluorescence to dihydroethidium in aortic slices and plasma nitrite/nitrate concentrations were measured to evaluate ROS and NO bioavailability, respectively. Results ACh-induced vasodilation was reduced in OVX rats as compared SHAM (Rmax: SHAM: 86±3.3 vs. OVX: 57±3.0%, p<0.01). Training prevented this response in OVX-TRA (Rmax: OVX-TRA: 88±2.0%, p<0.01), while did not change it in SHAM-TRA (Rmax: SHAM-TRA: 80±2.2%, p<0.01). The L-NAME incubation abolished the differences in ACh-induced relaxation among groups. SNP-induced vasodilation was not different among groups. OVX reduced nitrite/nitrate plasma concentrations and increased ROS in aortic slices, training as effective to restore these parameters to the SHAM levels. Conclusions Exercise training, even in estrogen deficiency conditions, is able to improve endothelial dependent vasodilation in rat aorta via enhanced NO bioavailability and reduced ROS levels. PMID:25923465

  7. Absence of systemic oxidative stress and increased CSF prostaglandin F2α in progressive MS

    PubMed Central

    Lam, Magda A.; Maghzal, Ghassan J.; Khademi, Mohsen; Piehl, Fredik; Ratzer, Rikke; Romme Christensen, Jeppe; Sellebjerg, Finn Thorup; Olsson, Tomas

    2016-01-01

    Objective: We aimed to investigate the role of oxidative stress in the progression of multiple sclerosis (MS). Methods: We determined by liquid chromatography–tandem mass spectrometry nonenzymatic (F2-isoprostanes) and enzymatic oxidation products of arachidonic acid (prostaglandin F2α [PGF2α]) in plasma and CSF of 45 controls (other neurologic disease [OND] with no signs of inflammation) and 62 patients with MS. Oxidation products were correlated with disease severity and validated biomarkers of inflammation (chemokine ligand 13; matrix metalloproteinase-9; osteopontin) and axonal damage (neurofilament light protein). Results: Compared with OND controls, plasma concentrations of F2-isoprostanes and PGF2α were significantly lower in patients with progressive disease, and decreased with increasing disability score (Expanded Disability Status Scale). In contrast, CSF concentrations of PGF2α, but not F2-isoprostanes, were significantly higher in patients with progressive disease than OND controls (p < 0.01). The content of PGF2α in CSF increased with disease severity (p = 0.044) and patient age (p = 0.022), although this increase could not be explained by age. CSF PGF2α decreased with natalizumab and methylprednisolone treatment and was unaffected by the use of nonsteroidal anti-inflammatory drug in secondary progressive MS. CSF PGF2α did not associate with validated CSF markers of inflammation and axonal damage that themselves did not associate with the Expanded Disability Status Scale. Conclusions: Our data suggest that MS progression is associated with low systemic oxidative activity. This may contribute to immune dysregulation with CNS inflammation accompanied by increased local cyclooxygenase-dependent lipid oxidation. PMID:27386506

  8. Elenoside increases intestinal motility

    PubMed Central

    Navarro, E; Alonso, SJ; Navarro, R; Trujillo, J; Jorge, E

    2006-01-01

    AIM: To study the effects of elenoside, an arylnaph-thalene lignan from Justicia hyssopifolia, on gastro-intestinal motility in vivo and in vitro in rats. METHODS: Routine in vivo experimental assessments were catharsis index, water percentage of boluses, intestinal transit, and codeine antagonism. The groups included we