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Sample records for flux arachidonic acid

  1. Metabolic flux analysis on arachidonic acid fermentation

    Institute of Scientific and Technical Information of China (English)

    JIN Mingjie; HUANG He; ZHANG Kun; YAN Jie; GAO Zhen

    2007-01-01

    The analysis of flux distributions in metabolic networks has become an important approach for understanding the fermentation characteristics of the process.A model of metabolic flux analysis of arachidonic acid (AA) synthesis in Mortierella alpina ME-1 was established and carbon flux distributions were estimated in different fermentation phases with different concentrations of N-source.During the exponential,decelerating and stationary phase,carbon fluxes to AA were 3.28%,8.80% and 6.97%,respectively,with sufficient N-source broth based on the flux of glucose uptake,and those were increased to 3.95%,19.21% and 39.29%,respectively,by regulating the shifts of carbon fluxes via fermentation with limited N-source broth and adding 0.05%NaNO3 at 96 h.Eventually AA yield was increased from 1.3 to 3.5 g.L-1.These results suggest a way to improve AA fermentation,that is,fermentation with limited N-source broth and adding low concentration N-source during the stationary phase.

  2. The Property and Application of Arachidonic Acid

    Institute of Scientific and Technical Information of China (English)

    王相勤; 姚建铭; 袁成凌; 王纪; 余增亮

    2002-01-01

    Arachidonic acid (AA) is one of the most important PUFAs (polyunsaturated fatty acids) in human body. A high-yield arachidonic acid-producing strain (mortierella alpina) was selected by ion implantation (the relative content of arachidonic acid is 70.2% among all fatty acids). This paper mainly introduced the structure, distribution, source, physiologic healthcare function and application of AA.

  3. Platelet-activating factor induces phospholipid turnover, calcium flux, arachidonic acid liberation, eicosanoid generation, and oncogene expression in a human B cell line

    Energy Technology Data Exchange (ETDEWEB)

    Schulam, P.G.; Kuruvilla, A.; Putcha, G.; Mangus, L.; Franklin-Johnson, J.; Shearer, W.T. (Baylor College of Medicine, Houston, TX (USA))

    1991-03-01

    Platelet-activating factor is a potent mediator of the inflammatory response. Studies of the actions of platelet-activating factor have centered mainly around neutrophils, monocytes, and platelets. In this report we begin to uncover the influence of platelet-activating factor on B lymphocytes. Employing the EBV-transformed human B cell line SKW6.4, we demonstrate that platelet-activating factor significantly alters membrane phospholipid metabolism indicated by the incorporation of 32P into phosphatidylcholine, phosphatidylinositol, and phosphatidic acid but not significantly into phosphatidylethanolamine at concentrations ranging from 10(-9) to 10(-6) M. The inactive precursor, lyso-platelet-activating factor, at a concentration as high as 10(-7) M had no effect on any of the membrane phospholipids. We also show that platelet-activating factor from 10(-12) to 10(-6) M induced rapid and significant elevation in intracellular calcium levels, whereas lyso-platelet-activating factor was again ineffective. We further demonstrate the impact of platelet-activating factor binding to B cells by measuring platelet-activating factor induced arachidonic acid release and 5-hydroxyeicosatetraenoic acid production. Moreover, platelet-activating factor was capable of inducing transcription of the nuclear proto-oncogenes c-fos and c-jun. Finally we explored the possible role of 5-hydroxyeicosatetraenoic acid as a regulator of arachidonic acid liberation demonstrating that endogenous 5-lipoxygenase activity modulates platelet-activating factor induced arachidonic acid release perhaps acting at the level of phospholipase A2. In summary, platelet-activating factor is shown here to have a direct and profound effect on a pure B cell line.

  4. [Studies on arachidonic acid production by Mortierella].

    Science.gov (United States)

    Bao, S; Zhu, F; Lin, W; Yao, R

    1997-10-01

    The effects of the incubation temperature, initial pH of the medium, carbon source and nitrogen source on the production of arachidonic acid by Mortierella sp. M10 were studied. Thought orthogonal experiments, the optimum culture medium was obtained (g/L): glucose, 100; yeast extract, 10; KNO3, 4.0; KH2PO4, 2.0; CaCl2.2H2O, 0.1; MgSO4.7H2O, 0.5; FeCl3.6H2O, 0.015; ZnSO4.7H2O, 0.0075; CuSO4.5H2O, 0.0005. Under the optimum culture conditions, the dry cell weight and arachidonic acid was 33.51 g/L and 0.827 g/L, respectively. The flask culture process was analysed.

  5. Arachidonic acid metabolites in pathogenic yeasts

    Directory of Open Access Journals (Sweden)

    Ells Ruan

    2012-08-01

    Full Text Available Abstract Although most of what is known about the biology and function of arachidonic acid metabolites comes from the study of mammalian biology, these compounds can also be produced by lower eukaryotes, including yeasts and other fungi. It is also in this group of organisms that the least is known about the metabolic pathways leading to the production of these compounds as well as the functions of these compounds in the biology of fungi and yeasts. This review will deal with the discovery of oxylipins from polyunsaturated fatty acids, and more specifically the arachidonic acid derived eicosanoids, such as 3-hydroxy eicosatetraenoic acid, prostaglandin F2α and prostaglandin E2, in yeasts starting in the early 1990s. This review will also focus on what is known about the metabolic pathways and/or proteins involved in the production of these compounds in pathogenic yeasts. The possible roles of these compounds in the biology, including the pathology, of these organisms will be discussed.

  6. Dietary arachidonic acid in perinatal nutrition

    DEFF Research Database (Denmark)

    Lauritzen, Lotte; Fewtrell, Mary; Agostoni, Carlo

    2015-01-01

    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......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...... 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...

  7. New uses of bioglycerin: production of arachidonic acid

    Science.gov (United States)

    Filamentous fungi of the genus Mortierella are known to produce arachidonic acid from glucose and M. alpina is currently used in industrial scale production of arachidonic acid in Japan. In anticipation of a large excess of co-product bioglycerin from the national biodiesel program, we would like ...

  8. Extracellular and intracellular arachidonic acid-induced contractions in rat aorta

    NARCIS (Netherlands)

    Filipeanu, CM; Brailoiu, E; Petrescu, G; Nelemans, SA

    1998-01-01

    Arachidonic acid induced contractions of de-endothelized rat aortic rings. A more potent effect was obtained after intracellular administration of arachidonic acid using liposomes. Contractions induced by extracellular arachidonic acid were inhibited similarly to phenylephrine-induced contractions b

  9. Mechanism of arachidonic acid action on syntaxin-Munc18.

    Science.gov (United States)

    Connell, Emma; Darios, Frédéric; Broersen, Kerensa; Gatsby, Naomi; Peak-Chew, Sew-Yeu; Rickman, Colin; Davletov, Bazbek

    2007-04-01

    Syntaxin and Munc18 are, in tandem, essential for exocytosis in all eukaryotes. Recently, it was shown that Munc18 inhibition of neuronal syntaxin 1 can be overcome by arachidonic acid, indicating that this common second messenger acts to disrupt the syntaxin-Munc18 interaction. Here, we show that arachidonic acid can stimulate syntaxin 1 alone, indicating that it is syntaxin 1 that undergoes a structural change in the syntaxin 1-Munc18 complex. Arachidonic acid is incapable of dissociating Munc18 from syntaxin 1 and, crucially, Munc18 remains associated with syntaxin 1 after arachidonic-acid-induced syntaxin 1 binding to synaptosomal-associated protein 25 kDa (SNAP25). We also show that the same principle operates in the case of the ubiquitous syntaxin 3 isoform, highlighting the conserved nature of the mechanism of arachidonic acid action. Neuronal soluble N-ethyl maleimide sensitive factor attachment protein receptors (SNAREs) can be isolated from brain membranes in a complex with endogenous Munc18, consistent with a proposed function of Munc18 in vesicle docking and fusion.

  10. DNA damage and mutations induced by arachidonic acid peroxidation.

    Science.gov (United States)

    Lim, Punnajit; Sadre-Bazzaz, Kianoush; Shurter, Jesse; Sarasin, Alain; Termini, John

    2003-12-30

    Endogenous cellular oxidation of omega6-polyunsaturated fatty acids (PUFAs) has long been recognized as a contributing factor in the development of various cancers. The accrual of DNA damage as a result of reaction with free radical and electrophilic aldehyde products of lipid peroxidation is believed to be involved; however, the genotoxic and mutation-inducing potential of specific membrane PUFAs remains poorly defined. In the present study we have examined the ability of peroxidizing arachidonic acid (AA, 20:4omega6) to induce DNA strand breaks, base modifications, and mutations. The time-dependent induction of single-strand breaks and oxidative base modifications by AA in genomic DNA was quantified using denaturing glyoxal gel electrophoresis. Mutation spectra were determined in XP-G fibroblasts and a repair-proficient line corrected for this defect by c-DNA complementation (XP-G(+)). Mutation frequencies were elevated from approximately 5- to 30-fold over the background following reaction of DNA with AA for various times. The XPG gene product was found to be involved in the suppression of mutations after extended reaction of DNA with AA. Arachidonic acid-induced base substitutions were consistent with the presence of both oxidized and aldehyde base adducts in DNA. The frequency of multiple-base substitutions induced by AA was significantly reduced upon correction for the XPG defect (14% vs 2%, P = 0.0015). Evidence is also presented which suggests that the induced frequency of multiple mutations is lesion dependent. These results are compared to published data for mutations stimulated by alpha,beta-unsaturated aldehydes identified as products of lipid peroxidation.

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

    Science.gov (United States)

    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.

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

    NARCIS (Netherlands)

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

    2011-01-01

    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

  13. Human milk arachidonic acid and docosahexaenoic acid contents increase following supplementation during pregnancy and lactation

    NARCIS (Netherlands)

    van Goor, Saskia A.; Dijick-Brouwer, D. A. Janneke; Hadders-Algra, Mijna; Doornbos, Bennard; Erwich, Jan Jaap H. M.; Schaafsma, Anne; Muskiet, Frits A. J.; Djick-Brouwer, D.A.J.

    2009-01-01

    Introduction: Docosahexaenoic acid (DHA) and arachidonic acid (AA) are important for neurodevelopment. Maternal diet influences milk DHA, whereas milk AA seems rather constant. We investigated milk AA, DHA and DHA/AA after supplementation of AA plus DHA, or DHA alone during pregnancy and lactation.

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

    NARCIS (Netherlands)

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

    2011-01-01

    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

  15. Arachidonic acid release from PC12 pheochromocytoma cells is regulated by I1-imidazoline receptors.

    Science.gov (United States)

    Ernsberger, P

    1998-10-15

    Rat PC 12 pheochromocytoma cells lack alpha2-adrenergic receptors but express plasma membrane I1-imidazoline receptors. In response to the I1-agonist moxonidine, diglycerides are generated via phosphatidylcholine-selective phospholipase C, and prostaglandin E2 is released. This report characterizes I-receptor-mediated release of arachidonic acid, the precursor to the prostaglandins. PC12 cells were incubated with [3H]arachidonic acid for 24 h and superfused with 0.01% bovine serum albumin in Krebs' physiological buffer at 1 ml/min. Calcium ionophore increased arachidonic acid release only marginally, implying that in PC12 cells arachidonic acid release is not driven by calcium. The I1-agonist moxonidine at concentrations between 10 nM and 1.0 microM rapidly elicited up to two-fold increases in [3H]arachidonic acid release. Guanabenz, a potent alpha2-agonist and I2-ligand, had no effect. The selective I1-antagonist efaroxan blocked the action of moxonidine. The phospholipase A2 inhibitor aristolochic acid had no effect, suggesting that arachidonic acid release may be through an indirect pathway, possibly involving diglycerides. Thus, I1-imidazoline receptors in PC12 cells are coupled to arachidonic acid release through an as yet unknown pathway.

  16. The Essentiality of Arachidonic Acid in Infant Development

    Directory of Open Access Journals (Sweden)

    Kevin B. Hadley

    2016-04-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  18. Arachidonic acid is a chemoattractant for Dictyostelium discoideum cells

    Indian Academy of Sciences (India)

    Ralph H Schaloske; Dagmar Blaesius; Christina Schlatterer; Daniel F Lusche

    2007-12-01

    Cyclic AMP (cAMP) is a natural chemoattractant of the social amoeba Dictyostelium discoideum. It is detected by cell surface cAMP receptors. Besides a signalling cascade involving phosphatidylinositol 3,4,5-trisphosphate (PIP3), Ca2+ signalling has been shown to have a major role in chemotaxis. Previously, we have shown that arachidonic acid (AA) induces an increase in the cytosolic Ca2+ concentration by causing the release of Ca2+ from intracellular stores and activating influx of extracellular Ca2+. Here we report that AA is a chemoattractant for D. discoideum cells differentiated for 8–9 h. Motility towards a glass capillary filled with an AA solution was dose-dependent and qualitatively comparable to cAMP-induced chemotaxis. Ca2+ played an important role in AA chemotaxis of wild-type Ax2 as ethyleneglycolbis(b-aminoethyl)-N,N,N′,N′-tetraacetic acid (EGTA) added to the extracellular buffer strongly inhibited motility. In the HM1049 mutant whose iplA gene encoding a putative Ins(1,4,5)P3-receptor had been knocked out, chemotaxis was only slightly affected by EGTA. Chemotaxis in the presence of extracellular Ca2+ was similar in both strains. Unlike cAMP, addition of AA to a cell suspension did not change cAMP or cGMP levels. A model for AA chemotaxis based on the findings in this and previous work is presented.

  19. Arachidonic acid production by Mortierella alpina using raw crop materials.

    Science.gov (United States)

    Cao, Ganggang; Guan, Zhengbing; Liu, Feixian G; Liao, Xiangru; Cai, Yujie

    2015-01-01

    Arachidonic acid (ARA) is one of the three essential fatty acids, and it is important for human body to keep healthy and is widely used. At present, expensive materials such as glucose and yeast extract are generally reported to be optimal for ARA production. A new cost-effective fermentation process including cheaper material for ARA production is of great significance. Feasibility of using corn meal and powdered soybean for fungal growth and lipid accumulation was evaluated by means of single factor test. N-hexadecane concentration was optimized, and the effect of temperature on biomass and ARA content was examined. Mortierella alpina made better use of the aforementioned material as carbon and nitrogen sources for both hyphae growth and ARA production compared with glucose and yeast extract. Maximal levels of 10.9 g/L ARA and 26.1 g/L total lipids were obtained when 66 g/L corn meal, 54 g/L soybean meal and 6% (v/v) n-hexadecane were supplemented. A temperature-shift strategy involved three steps, namely, 30°C (3 days) - 25°C (4 days) - 20°C (4 days), which further improved ARA production by 24.7%. Several factors such as carbon and nitrogen sources, temperature and dissolved oxygen had great influence on biomass and microbial oil production. Mortierella alpina preferred corn and soybean meal compared with glucose and yeast extract, which would surely alleviate the high cost of ARA production. Based on this study, the new process is both low cost and practicable.

  20. Arachidonic acid production by Mortierella alpina using raw crop materials

    Directory of Open Access Journals (Sweden)

    Ganggang Cao

    2015-06-01

    Full Text Available Background. Arachidonic acid (ARA is one of the three essential fatty acids, and it is important for human body to keep healthy and is widely used. At present, expensive materials such as glucose and yeast extract are generally reported to be optimal for ARA production. A new cost-effective fermentation process including cheaper material for ARA production is of great signifi cance. Material and methods. Feasibility of using corn meal and powdered soybean for fungal growth and lipid accumulation was evaluated by means of single factor test. N-hexadecane concentration was optimized, and the effect of temperature on biomass and ARA content was examined. Results. Mortierella alpina made better use of the aforementioned material as carbon and nitrogen sources for both hyphae growth and ARA production compared with glucose and yeast extract. Maximal levels of 10.9 g/L ARA and 26.1 g/L total lipids were obtained when 66 g/L corn meal, 54 g/L soybean meal and 6% (v/v n-hexadecane were supplemented. A temperature-shift strategy involved three steps, namely, 30°C (3 days – 25°C (4 days – 20°C (4 days, which further improved ARA production by 24.7%. Conclusion. Several factors such as carbon and nitrogen sources, temperature and dissolved oxygen had great infl uence on biomass and microbial oil production. Mortierella alpina preferred corn and soybean meal compared with glucose and yeast extract, which would surely alleviate the high cost of ARA production. Based on this study, the new process is both low cost and practicable.

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

    Science.gov (United States)

    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.

  2. Effect of supplementation of arachidonic acid (AA) or a combination of AA plus docosahexaenoic acid on breastmilk fatty acid composition

    NARCIS (Netherlands)

    Smit, EN; Koopmann, M; Boersma, ER; Muskiet, FAJ

    2000-01-01

    We investigated whether supplementation with arachidonic acid (20:4 omega 6; AA), ora combination of AA and docosahexaenoic acid (22:6 omega 3; DHA) would affect human milk polyunsaturated fatty acid (PUFA) composition. Ten women were daily supplemented with 300 mg AA, eight with 300 mg AA, 110 mg e

  3. Prenatal long-chain polyunsaturated fatty acid status : the importance of a balanced intake of docosahexaenoic acid and arachidonic acid

    NARCIS (Netherlands)

    Hadders-Algra, Mijna

    2008-01-01

    This review addresses the effect of prenatal long-chain polyunsaturated fatty acid (LCPUFA) status on neuro-developmental outcome. It focuses on the major LPCUFA doxosahexaenoic acid (DNA; 22:6 omega 3) and arachidonic acid (AA; 20:4 omega 6). Due to enzymatic competition high DHA intake results in

  4. Lower fetal status of docosahexaenoic acid, arachidonic acid and essential fatty acids is associated with less favorable neonatal neurological condition

    NARCIS (Netherlands)

    Dijck-Brouwer, DAJ; Hadders-Algra, M; Bouwstra, H; Decsi, T; Boehm, G; Martini, IA; Boersma, ER; Muskiet, FAJ

    2005-01-01

    Long-chain polyunsaturated fatty acids, notably arachidonic (AA) and docosahexaenoic (DHA) acids are abundant in brain and may be conditionally essential in fetal life. We investigated umbilical artery (UA) and vein (UV) fatty acid compositions and early neonatal neurological condition in 317 term i

  5. Prenatal long-chain polyunsaturated fatty acid status : the importance of a balanced intake of docosahexaenoic acid and arachidonic acid

    NARCIS (Netherlands)

    Hadders-Algra, Mijna

    2008-01-01

    This review addresses the effect of prenatal long-chain polyunsaturated fatty acid (LCPUFA) status on neuro-developmental outcome. It focuses on the major LPCUFA doxosahexaenoic acid (DNA; 22:6 omega 3) and arachidonic acid (AA; 20:4 omega 6). Due to enzymatic competition high DHA intake results in

  6. Effect of supplementation of arachidonic acid (AA) or a combination of AA plus docosahexaenoic acid on breastmilk fatty acid composition

    NARCIS (Netherlands)

    Smit, EN; Koopmann, M; Boersma, ER; Muskiet, FAJ

    We investigated whether supplementation with arachidonic acid (20:4 omega 6; AA), ora combination of AA and docosahexaenoic acid (22:6 omega 3; DHA) would affect human milk polyunsaturated fatty acid (PUFA) composition. Ten women were daily supplemented with 300 mg AA, eight with 300 mg AA, 110 mg

  7. Raloxifene and hormone replacement therapy increase arachidonic acid and docosahexaenoic levels in postmenopausal women

    NARCIS (Netherlands)

    Giltay, E.J.; Duschek, E.J.J.; Katan, M.B.; Neele, S.J.; Netelenbos, J.C.; Zock, P.L.

    2004-01-01

    Estrogens may affect the essential n-6 and n-3 fatty acids arachidonic acid (AA; C20:4n-6) and docosahexaenoic acid (DHA; C22:6n-3). Therefore, we investigated the long-term effects of hormone replacement therapy and raloxifene, a selective estrogen-receptor modulator, in two randomized, double-blin

  8. Arachidonic acid reduces the stress response of gilthead seabream Sparus aurata L.

    NARCIS (Netherlands)

    Anholt, R.D. van; Spanings, F.A.T.; Koven, W.M.; Nixon, O.; Wendelaar Bonga, S.E.

    2004-01-01

    In this study the influence of the dietary level of the fatty acid arachidonic acid (ArA, 20:4n-6) was determined on the acute stress response and osmoregulation of adult gilthead seabream Sparus aurata L. Seabream were fed a diet containing either 0.9% or 2.4% of total fatty acids as ArA for 18 day

  9. Raloxifene and hormone replacement therapy increase arachidonic acid and docosahexaenoic levels in postmenopausal women

    NARCIS (Netherlands)

    Giltay, E.J.; Duschek, E.J.J.; Katan, M.B.; Neele, S.J.; Netelenbos, J.C.; Zock, P.L.

    2004-01-01

    Estrogens may affect the essential n-6 and n-3 fatty acids arachidonic acid (AA; C20:4n-6) and docosahexaenoic acid (DHA; C22:6n-3). Therefore, we investigated the long-term effects of hormone replacement therapy and raloxifene, a selective estrogen-receptor modulator, in two randomized,

  10. Arachidonic acid reduces the stress response of gilthead seabream Sparus aurata L.

    NARCIS (Netherlands)

    Anholt, R.D. van; Spanings, F.A.T.; Koven, W.M.; Nixon, O.; Wendelaar Bonga, S.E.

    2004-01-01

    In this study the influence of the dietary level of the fatty acid arachidonic acid (ArA, 20:4n-6) was determined on the acute stress response and osmoregulation of adult gilthead seabream Sparus aurata L. Seabream were fed a diet containing either 0.9% or 2.4% of total fatty acids as ArA for 18

  11. Research on Arachidonic Acid and Eicosapentaenoic Acid Anabolic Metabolism in Diasporangium sp.

    Institute of Scientific and Technical Information of China (English)

    DAI Chuan-chao; XU Yu-fen; XIA Shun-xiang; ZHAO Mo; YE Yu-cheng

    2010-01-01

    The fatty acids of a strain of Diasporangium sp.had been analyzed by using GC-MS.The fatty acids of twenty mutants were determined.Based on these results,the producing of eicosapentaenoic acid(EPA)supposed via 18∶2,18∶3,20∶3,20∶4 which all belong to ω-6 fatty acids.The ω-3 desaturation was undertaken at arachidonic acid(AA).In addition,mutant strains resulted in enhanced content of AA which could get two times more than initial strain,but no compact on EPA.

  12. The Arachidonic Acid Metabolome Serves as a Conserved Regulator of Cholesterol Metabolism

    NARCIS (Netherlands)

    Demetz, Egon; Schroll, Andrea; Auer, Kristina; Heim, Christiane; Patsch, Josef R.; Eller, Philipp; Theurl, Markus; Theurl, Igor; Theurl, Milan; Seifert, Markus; Lener, Daniela; Stanzl, Ursula; Haschka, David; Asshoff, Malte; Dichtl, Stefanie; Nairz, Manfred; Huber, Eva; Stadlinger, Martin; Moschen, Alexander R.; Li, Xiaorong; Pallweber, Petra; Scharnagl, Hubert; Stojakovic, Tatjana; Maerz, Winfried; Kleber, Marcus E.; Garlaschelli, Katia; Uboldi, Patrizia; Catapano, Alberico L.; Stellaard, Frans; Rudling, Mats; Kuba, Keiji; Imai, Yumiko; Arita, Makoto; Schuetz, John D.; Pramstaller, Peter P.; Tietge, Uwe J. F.; Trauner, Michael; Norata, Giuseppe D.; Claudel, Thierry; Hicks, Andrew A.; Weiss, Guenter; Tancevski, Ivan

    2014-01-01

    Cholesterol metabolism is closely interrelated with cardiovascular disease in humans. Dietary supplementation with omega-6 polyunsaturated fatty acids including arachidonic acid (AA) was shown to favorably affect plasma LDL-C and HDL-C. However, the underlying mechanisms are poorly understood. By co

  13. Dietary supplementation with arachidonic acid in tilapia (Oreochromis mossambicus) reveals physiological effects not mediated by prostaglandins.

    NARCIS (Netherlands)

    Anholt, R.D. van; Spanings, F.A.T.; Koven, W.M.; Wendelaar Bonga, S.E.

    2004-01-01

    This study aims to clarify the role of the polyunsaturated fatty acid arachidonic acid (ArA, 20:4n-6) in the stress response of Mozambique tilapia (Oreochromis mossambicus). ArA is converted into eicosanoids, including prostaglandins, which can influence the response to stressors. Tilapia, a species

  14. Dietary supplementation with arachidonic acid in tilapia (Oreochromis mossambicus) reveals physiological effects not mediated by prostaglandins.

    NARCIS (Netherlands)

    Anholt, R.D. van; Spanings, F.A.T.; Koven, W.M.; Wendelaar Bonga, S.E.

    2004-01-01

    This study aims to clarify the role of the polyunsaturated fatty acid arachidonic acid (ArA, 20:4n-6) in the stress response of Mozambique tilapia (Oreochromis mossambicus). ArA is converted into eicosanoids, including prostaglandins, which can influence the response to stressors. Tilapia, a species

  15. Production of metabolic products of arachidonic acid during cell-cell interactions

    Energy Technology Data Exchange (ETDEWEB)

    Marcus, A.J.; Safier, L.B.; Broekman, M.J.; Ullman, H.L.; Islam, N.; Sorrell, T.C.; Serhan, C.N.; Weissmann, G.; Oglesby, T.D.; Gorman, R.R.

    1984-09-01

    Interactions of human platelets and neutrophils were studied with particular reference to the arachidonic acid pathway. Suspensions of (3H)arachidonate-labeled platelets and unlabeled neutrophils were stimulated with ionophore A23187. We detected several radioactive arachidonate metabolites, which are not produced by platelets alone. These included (3H)-labeled leukotriene B4 (LTB4), dihydroxy-eicosatetraeonic acid (DiHETE), and 5-hydroxy-eicosatetraenoic acid (5-HETE). DiHETE was formed when the platelet product (3H)12-HETE was added to ionophore-stimulated neutrophils. In addition, DiHETE was the major metabolite when (3H)5-HETE, a neutrophil arachidonate product, was added to stimulated platelets. We therefore suggest that upon stimulation, platelet-derived arachidonate can serve as precursor for the neutrophil-derived eicosanoids LTB4 and 5-HETE, and the platelet-derived product 12-HETE can be metabolized to DiHETE by stimulated human neutrophils. More recently we have shown that 12-HETE from thrombin-stimulated platelets can also be metabolized to a new product, 12,20-DiHETE, by

  16. DMPD: Regulation of arachidonic acid release and cytosolic phospholipase A2activation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 10080535 Regulation of arachidonic acid release and cytosolic phospholipase A2activ...ation. Gijon MA, Leslie CC. J Leukoc Biol. 1999 Mar;65(3):330-6. (.png) (.svg) (.html) (.csml) Show Regulation... of arachidonic acid release and cytosolic phospholipase A2activation. PubmedID 10080535 Title Regulation

  17. Effect of amiloride on arachidonic acid and histamine release from rat mast cells

    DEFF Research Database (Denmark)

    Linnebjerg, H.; Hansen, Harald S.; Jensen, B.

    1989-01-01

    The effect of a putative Na/H exchange inhibition on histamine and [C]arachidonic acid ([C]AA) release has been examined in rat peritoneal mast cells, using either addition of amiloride or removal of extracellular Na. The cells were stimulated by non-immunological agents, i.e. calcium ionophore A...

  18. Effect of gomisin A (TJN-101) on the arachidonic acid cascade in macrophages.

    Science.gov (United States)

    Ohkura, Y; Mizoguchi, Y; Morisawa, S; Takeda, S; Aburada, M; Hosoya, E

    1990-02-01

    It has been reported that leukotrienes (LTs) may play a role in inflammatory liver diseases, and several inhibitors of LTs show an inhibitory effect on experimental liver injuries. In this study, the effect of Gomisin A (TJN-101), which is a lignan component of schisandra fruits, on the arachidonic acid cascade in macrophages was examined to explain the mechanisms of the inhibitory effect of TJN-101 on liver injuries. The production of leukotriene B4 was suppressed by treatment with TJN-101, while the activity of 5-lipoxygenase was not affected. The release of arachidonic acid from macrophages stimulated with fMet-Leu-Phe or the Ca++ ionophore A23187 was suppressed by treatment with TJN-101. The activity of phospholipase A2 was not affected by treatment with TJN-101. These results suggested that TJN-101 produces an inhibitory effect on the biosynthesis of LTs by preventing the release of arachidonic acid, and it was thought that the preventive effect on the arachidonic acid cascade may be partially associated with the inhibitory effect of TJN-101 on liver injuries.

  19. Uptake and release of arachidonic acid by platelets and cultured cells

    Energy Technology Data Exchange (ETDEWEB)

    Neufeld, E.J.

    1985-01-01

    The release by thrombin of arachidonic acid, and the accompanying phospholipid metabolism, were studied in human platelets. At 23/sup 0/C, arachidonate release was half-maximal by 10-30 sec after stimulation, and preceded substantial increase in phosphatidic acid (PA) mass. (/sup 3/H)-glycerol-labeled platelets synthesized phospholipids from (/sup 3/H) PA at a rate of 0.08-0.3 nmol/min/10/sup 9/ cells at 37/sup 0/C. This rate of PA turnover was not enhanced by thrombin stimulation. Thus, an increase in PA mass is not a necessary event in the pathway loading to arachidonate release, and the release of several nmol of arachidonate from PI in the first minute after thrombin stimulation could not have arisen via PA as an intermediate. Biological function of arachidonate-specific acyl-CoA synthetase was examined in platelets and in HSDM/sub 1/C/sub 1/ murine fibrosarcoma cells. Washed platelets were found to take up and esterify into cellular phospholipids eicosanoid precursor fatty acids present at concentrations of 5-500 nM. The uptake process was saturable with respect to fatty acid concentration, with apparent K/sub m/ less than or equal to 85 nM. Stearate, oleate and linoleate were taken up less rapidly, and with higher apparent K/sub m/'s (greater than or equal to 170 nM). High affinity uptake was also found in HSDM/sub 1/C/sub 1/ cells. The fatty acid structural requirements of arachidonoyl-CoA synthetase were examined. Among common mammalian fatty acids, only eicosanoid precursors and docosahexaenoate could serve as substrates. These studies strongly suggest that the synthetase is required for normal eicosanoid homeostasis.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Expression analysis for genes involved in arachidonic acid biosynthesis in Mortierella alpina CBS 754.68.

    Science.gov (United States)

    Samadlouie, Hamid-Reza; Hamidi-Esfahani, Zohreh; Alavi, Seyed-Mehdi; Varastegani, Boshra

    2014-01-01

    The time courses for production of fungal biomass, lipid, phenolic and arachidonic acid (ARA) as well as expression of the genes involved in biosynthesis of ARA and lipid were examined in Mortierella alpina CBS 754.68. A significant increase in the arachidonic acid content in lipids that coincided with reduced levels of lipid was obtained. Reduced gene expression occurred presumably due to the steady reduction of carbon and nitrogen resources. However, these energy resources were inefficiently compensated by the breakdown of the accumulated lipids that in turn, induced up-regulated expression of the candidate genes. The results further indicated that the expression of the GLELO encoding gene is a rate-limiting step in the biosynthesis of ARA in the early growth phase.

  4. Expression analysis for genes involved in arachidonic acid biosynthesis in Mortierella alpina CBS 754.68

    Directory of Open Access Journals (Sweden)

    Hamid-Reza Samadlouie

    2014-06-01

    Full Text Available The time courses for production of fungal biomass, lipid, phenolic and arachidonic acid (ARA as well as expression of the genes involved in biosynthesis of ARA and lipid were examined in Mortierella alpina CBS 754.68. A significant increase in the arachidonic acid content in lipids that coincided with reduced levels of lipid was obtained. Reduced gene expression occurred presumably due to the steady reduction of carbon and nitrogen resources. However, these energy resources were inefficiently compensated by the breakdown of the accumulated lipids that in turn, induced up-regulated expression of the candidate genes. The results further indicated that the expression of the GLELO encoding gene is a rate-limiting step in the biosynthesis of ARA in the early growth phase.

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

    Science.gov (United States)

    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.

  6. Immunohistochemical localization of key arachidonic acid metabolism enzymes during fracture healing in mice.

    Directory of Open Access Journals (Sweden)

    Hsuan-Ni Lin

    Full Text Available This study investigated the localization of critical enzymes involved in arachidonic acid metabolism during the initial and regenerative phases of mouse femur fracture healing. Previous studies found that loss of cyclooxygenase-2 activity impairs fracture healing while loss of 5-lipoxygenase activity accelerates healing. These diametric results show that arachidonic acid metabolism has an essential function during fracture healing. To better understand the function of arachidonic acid metabolism during fracture healing, expression of cyclooxygenase-1 (COX-1, cyclooxygenase -2 (COX-2, 5-lipoxygenase (5-LO, and leukotriene A4 hydrolase (LTA4H was localized by immunohistochemistry in time-staged fracture callus specimens. All four enzymes were detected in leukocytes present in the bone marrow and attending inflammatory response that accompanied the fracture. In the tissues surrounding the fracture site, the proportion of leukocytes expressing COX-1, COX-2, or LTA4H decreased while those expressing 5-LO remained high at 4 and 7 days after fracture. This may indicate an inflammation resolution function for 5-LO during fracture healing. Only COX-1 was consistently detected in fracture callus osteoblasts during the later stages of healing (day 14 after fracture. In contrast, callus chondrocytes expressed all four enzymes, though 5-LO appeared to be preferentially expressed in newly differentiated chondrocytes. Most interestingly, osteoclasts consistently and strongly expressed COX-2. In addition to bone surfaces and the growth plate, COX-2 expressing osteoclasts were localized at the chondro-osseous junction of the fracture callus. These observations suggest that arachidonic acid mediated signaling from callus chondrocytes or from callus osteoclasts at the chondro-osseous junction regulate fracture healing.

  7. Targeted Chiral Analysis of Bioactive Arachidonic Acid Metabolites Using Liquid-Chromatography-Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Clementina Mesaros

    2012-04-01

    Full Text Available A complex structurally diverse series of eicosanoids arises from the metabolism of arachidonic acid. The metabolic profile is further complicated by the enantioselectivity of eicosanoid formation and the variety of regioisomers that arise. In order to investigate the metabolism of arachidonic acid in vitro or in vivo, targeted methods are advantageous in order to distinguish between the complex isomeric mixtures that can arise by different metabolic pathways. Over the last several years this targeted approach has become more popular, although there are still relatively few examples where chiral targeted approaches have been employed to directly analyze complex enantiomeric mixtures. To efficiently conduct targeted eicosanoid analyses, LC separations are coupled with collision induced dissociation (CID and tandem mass spectrometry (MS/MS. Product ion profiles are often diagnostic for particular regioisomers. The highest sensitivity that can be achieved involves the use of selected reaction monitoring/mass spectrometry (SRM/MS; whereas the highest specificity is obtained with an SRM transitions between an intense parent ion, which contains the intact molecule (M and a structurally significant product ion. This review article provides an overview of arachidonic acid metabolism and targeted chiral methods that have been utilized for the analysis of the structurally diverse eicosanoids that arise.

  8. Effects of fluticasone propionate inhalation on levels of arachidonic acid metabolites in patients with chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Gert T. Verhoeven

    2001-01-01

    Full Text Available Background: In smoking COPD patients the bronchoalveolar lavage (BAL fluid contains high numbers of inflammatory cells. These cells might produce arachidonic acid (AA metabolites, which contribute to inflammation and an increased bronchomotor tone.

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

    OpenAIRE

    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...

  10. Arachidonic acid-metabolizing cytochrome P450 enzymes are targets of {omega}-3 fatty acids.

    Science.gov (United States)

    Arnold, Cosima; Markovic, Marija; Blossey, Katrin; Wallukat, Gerd; Fischer, Robert; Dechend, Ralf; Konkel, Anne; von Schacky, Clemens; Luft, Friedrich C; Muller, Dominik N; Rothe, Michael; Schunck, Wolf-Hagen

    2010-10-22

    Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) protect against cardiovascular disease by largely unknown mechanisms. We tested the hypothesis that EPA and DHA may compete with arachidonic acid (AA) for the conversion by cytochrome P450 (CYP) enzymes, resulting in the formation of alternative, physiologically active, metabolites. Renal and hepatic microsomes, as well as various CYP isoforms, displayed equal or elevated activities when metabolizing EPA or DHA instead of AA. CYP2C/2J isoforms converting AA to epoxyeicosatrienoic acids (EETs) preferentially epoxidized the ω-3 double bond and thereby produced 17,18-epoxyeicosatetraenoic (17,18-EEQ) and 19,20-epoxydocosapentaenoic acid (19,20-EDP) from EPA and DHA. We found that these ω-3 epoxides are highly active as antiarrhythmic agents, suppressing the Ca(2+)-induced increased rate of spontaneous beating of neonatal rat cardiomyocytes, at low nanomolar concentrations. CYP4A/4F isoforms ω-hydroxylating AA were less regioselective toward EPA and DHA, catalyzing predominantly ω- and ω minus 1 hydroxylation. Rats given dietary EPA/DHA supplementation exhibited substantial replacement of AA by EPA and DHA in membrane phospholipids in plasma, heart, kidney, liver, lung, and pancreas, with less pronounced changes in the brain. The changes in fatty acids were accompanied by concomitant changes in endogenous CYP metabolite profiles (e.g. altering the EET/EEQ/EDP ratio from 87:0:13 to 27:18:55 in the heart). These results demonstrate that CYP enzymes efficiently convert EPA and DHA to novel epoxy and hydroxy metabolites that could mediate some of the beneficial cardiovascular effects of dietary ω-3 fatty acids.

  11. Docosahexaenoic acid suppresses arachidonic acid-induced proliferation of LS-174T human colon carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    Piet Habbel; Karsten H Weylandt; Katja Lichopoj; Johannes Nowak; Martin Purschke; Jing-Dong Wang; Cheng-Wei He; Daniel C Baumgart; Jing X Kang

    2009-01-01

    AIM: To investigate the impact of arachidonic acid (AA) and docosahexaenoic acid (DHA) and their combination on colon cancer cell growth.METHODS: The LS-174T colon cancer cell line was used to study the role of the prostaglandin precursor AA and the omega-3 polyunsaturated fatty acid DHA on cell growth. Cell viability was assessed in XTT assays. For analysis of cell cycle and cell death, flow cytometry and DAPI staining were applied. Expression of cyclooxygenase-2 (COX-2), p21 and bcl-2 in cells incubated with AA or DHA was examined by real-time RT-PCR. Prostaglandin E2 (PGE2) generation in the presence of AA and DHA was measured using a PGE2ELISA.RESULTS: AA increased cell growth, whereas DHA reduced viability of LS 174T cells in a time- and dosedependent manner. Furthermore, DHA down- regulated mRNA of bcl-2 and up-regulated p21. Interestingly,DHA was able to suppress AA-induced cell proliferation and significantly lowered AA-derived PGE2 formation.DHA also down-regulated COX-2 expression. In addition to the effect on PGE2 formation, DHA directly reduced PGE2-induced cell proliferation in a dosedependent manner.CONCLUSION: These results suggest that DHA can inhibit the pro-proliferative effect of abundant AA or PGE2.

  12. Arachidonic acid, an omega-6 fatty acid, induces cytoplasmic phospholipase A2 in prostate carcinoma cells.

    Science.gov (United States)

    Hughes-Fulford, Millie; Tjandrawinata, Raymond R; Li, Chai-Fei; Sayyah, Sina

    2005-09-01

    For the past 60 years, dietary intake of essential fatty acids has increased. Moreover, the omega-6 fatty acids have recently been found to play an important role in regulation of gene expression. Proliferation of human prostate cells was significantly increased 48 h after arachidonic acid (AA) addition. We have analyzed initial uptake using nile red fluorescence and we found that the albumin conjugated AA is endocytosed into the cells followed by the induction of RNA within minutes, protein and PGE2 synthesis within hours. Here we describe that AA induces expression of cytosolic phospholipase A2 (cPLA2) in a dose-dependent manner and that this upregulation is dependent upon downstream synthesis of PGE2. The upregulation of cox-2 and cPLA2 was inhibited by flurbiprofen, a cyclooxygenase (COX) inhibitor, making this a second feed-forward enzyme in the eicosanoid pathway. Cox-2 specific inhibitors are known to inhibit colon and prostate cancer growth in humans; however, recent findings show that some of these have cardiovascular complications. Since cPLA2 is upstream in the eicosanoid pathway, it may be a good alternative for a pharmaceutical target for the treatment of cancer.

  13. Eicosapentaenoic Acid, Arachidonic Acid and Eicosanoid Metabolism in Juvenile Barramundi Lates calcarifer.

    Science.gov (United States)

    Salini, Michael J; Wade, Nicholas M; Araújo, Bruno C; Turchini, Giovanni M; Glencross, Brett D

    2016-08-01

    A two part experiment was conducted to assess the response of barramundi (Lates calcarifer; initial weight = 10.3 ± 0.03 g; mean ± S.D.) fed one of five diets with varying eicosapentaenoic acid (diets 1, 5, 10, 15 and 20 g/kg) or one of four diets with varying arachidonic acid (1, 6, 12, 18 g/kg) against a fish oil control diet. After 6 weeks of feeding, the addition of EPA or ARA did not impact on growth performance or feed utilisation. Analysis of the whole body fatty acids showed that these reflected those of the diets. The ARA retention demonstrated an inversely related curvilinear response to either EPA or ARA. The calculated marginal utilisation efficiencies of EPA and ARA were high (62.1 and 91.9 % respectively) and a dietary ARA requirement was defined (0.012 g/kg(0.796)/day). The partial cDNA sequences of genes regulating eicosanoid biosynthesis were identified in barramundi tissues, namely cyclooxygenase 1 (Lc COX1a, Lc COX1b), cyclooxygenase 2 (Lc COX2) and lipoxygenase (Lc ALOX-5). Both Lc COX2 and Lc ALOX-5 expression in the liver tissue were elevated in response to increasing dietary ARA, meanwhile expression levels of Lc COX2 and the mitochondrial fatty acid oxidation gene carnitine palmitoyltransferase 1 (Lc CPT1a) were elevated in the kidney. A low level of EPA increased the expression of Lc COX1b in the liver. Consideration should be given to the EPA to ARA balance for juvenile barramundi in light of nutritionally inducible nature of the cyclooxygenase and lipoxygenase enzymes.

  14. Maternal and fetal brain contents of docosahexaenoic acid (DHA) and arachidonic acid (AA) at various essential fatty acid (EFA), DHA and AA dietary intakes during pregnancy in mice

    NARCIS (Netherlands)

    van Goor, Saskia A; Dijck-Brouwer, D A Janneke; Fokkema, M Rebecca; van der Iest, Theo Hans; Muskiet, Frits A J

    We investigated essential fatty acids (EFA) and long-chain polyunsaturated fatty acids (LCP) in maternal and fetal brain as a function of EFA/LCP availability to the feto-maternal unit in mice. Diets varying in parent EFA, arachidonic acid (AA), and docosahexaenoic acid (DHA) were administered from

  15. Maternal and fetal brain contents of docosahexaenoic acid (DHA) and arachidonic acid (AA) at various essential fatty acid (EFA), DHA and AA dietary intakes during pregnancy in mice

    NARCIS (Netherlands)

    van Goor, Saskia A; Dijck-Brouwer, D A Janneke; Fokkema, M Rebecca; van der Iest, Theo Hans; Muskiet, Frits A J

    2008-01-01

    We investigated essential fatty acids (EFA) and long-chain polyunsaturated fatty acids (LCP) in maternal and fetal brain as a function of EFA/LCP availability to the feto-maternal unit in mice. Diets varying in parent EFA, arachidonic acid (AA), and docosahexaenoic acid (DHA) were administered from

  16. PHYSIOLOGICAL INHIBITORY EFFECT OF OCS IN ARACHIDONIC ACID-RICH PARIETOCHLORIS INCISA (TREBOUXIOPHYCEAE, CHLOROPHYTA)

    Institute of Scientific and Technical Information of China (English)

    刘建国; 张成武; ZviCohen; AmosRichmond

    2002-01-01

    Parietochloris incisa is an arachidonic acid-rich snow green alga. The main physiological profiles, such as ash free dry weight (AFDW), chlorophyll, carotenoid, protein and total fatty acids (TFA), in this alga exposed to old culture supernatant (OCS) at the decline phase or its crude ethyl acetate extracts (CEAE) were investigated by using tubular photobioreactors of different diameters. Results showed that both OCS and CEAE had strong inhibitory effect on the above physiological parameters. The longer the culture was exposed to OCS and the more CEAE were added into the algal culture, the more the above physiological properties were inhibited. Arachidonic acid (AA), the dominant component of fatty acids in this alga, was also seriously inhibited with respect to total TFA, AFDW of cell mass, or culture volume, due to a prebable reduction of enzymes activities catalyzing chain elongation from C18:1ω9 to AA. These results incontestably evidenced that some CEAE dissolving substances existing in OCS, like auto-inhibitors, inhibited P. incisa growth through feedback. Hence, any efficient removal of auto-inhibitors from algal culture to decrease their bioactivity could be good for maximal production of desired products like AA.

  17. PHYSIOLOGICAL INHIBITORY EFFECT OF OCS IN ARACHIDONIC ACID-RICH PARIETOCHLORIS INCISA (TREBOUXIOPHYCEAE,CHLOROPHYTA)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Parietochloris incisa is an arachidonic acid-rich snow green alga. The main phy siological profiles, such as ash free dry weight (AFDW), chlorophyll, carotenoid , protein and total fatty acids (TFA), in this alga exposed to old culture super natant (OCS) at the decline phase or its crude ethyl acetate extracts (CEAE) wer e investigated by using tubular photobioreactors of different diameters. Results showed that both OCS and CEAE had strong inhibitory effect on the above physiol ogical parameters. The longer the culture was exposed to OCS and the more CEAE w ere added into the algal culture, the more the above physiological properties we re inhibited. Arachidonic acid (AA), the dominant component of fatty acids in th is alga, was also seriously inhibited with respect to total TFA, AFDW of cell ma ss, or culture volume, due to a probable reduction of enzymes activities catalyz ing chain elongation from C18:1ω9 to AA. These results incontestably evidenced t hat some CEAE dissolving substances existing in OCS, like auto-inhibitors, inhi bited P. incisa growth through feedback. Hence, any efficient removal of aut o-i nhibitors from algal culture to decrease their bioactivity could be good for max imal production of desired products like AA.

  18. Physiological inhibitory effect of ocs in arachidonic acid-rich Parietochloris incisa (trebouxiophyceae, chlorophyta)

    Science.gov (United States)

    Liu, Jian-Guo; Zhang, Cheng-Wu; Cohen, Zvi; Richmond, Amos

    2002-09-01

    Parietochloris incisa is an arachidonic acid-rich snow green alga. The main physiological profiles, such as ash free dry weight (AFDW), chlorophyll, carotenoid, protein and total fatty acids (TFA), in this alga exposed to old culture supernatant (OCS) at the decline phase or its crude ethyl acetate extracts (CEAE) were investigated by using tubular photobioreactors of different diameters. Results showed that both OCS and CEAE had strong inhibitory effect on the above physiological parameters. The longer the culture was exposed to OCS and the more CEAE were added into the algal culture, the more the above physiological properties were inhibited. Arachidonic acid (AA), the dominant component of fatty acids in this alga, was also seriously inhibited with respect to total TFA, AFDW of cell mass, or culture volume, due to a probable reduction of enzymes activities catalyzing chain elongation from C18; 1ω9 to AA. These results incontestably evidenced that some CEAE dissolving substances existing in OCS. like auto-inhibitors, inhibited P. incisa growth through feedback. Hence, any efficient removal of auto-inhibitors from algal culture to decrease their bioactivity could be good for maximal production of desired products like AA.

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

    Energy Technology Data Exchange (ETDEWEB)

    Madden, M.C.; Eling, T.E.; Dailey, L.A.; Friedman, M. (Univ. of North Carolina, Chapel Hill (USA))

    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.

  20. The effect of prostaglandin E2 and arachidonic acid on dentinogenesis in pigs.

    Science.gov (United States)

    Burke, A; Weiler, H

    2001-01-01

    The rate of dentinogenesis for the pig is quantified and the effects of dietary arachidonic acid supplementation and/or exogenous prostaglandin on dentine formation are defined. Thirty-six pigs were randomised to four groups, receiving either standard or supplemented formula and either prostaglandin E2 or placebo injections for fifteen days. Double tetracycline banding is used to measure rate of growth in the teeth. The average rate of dentinogenesis for all the study animals is 17.96 microm/day. Results show that the rate of dentinogenesis is not significantly affected by the interaction of hormone and dietary supplementation.

  1. Role of mitochondria in programmed cell death mediated by arachidonic acid-derived eicosanoids.

    Science.gov (United States)

    Yin, Huiyong; Zhou, Yunhua; Zhu, Mingjiang; Hou, Sarina; Li, Zi; Zhong, Huiqin; Lu, Jianhong; Meng, Tao; Wang, Junhong; Xia, Lin; Xu, Yue; Wu, Yuncheng

    2013-05-01

    Arachidonic acid-derived eicosanoids from cyclooxygenases, lipoxygenases, and cytochrome P450 are important lipid mediators involved in numerous homeostatic and pathophysiological processes. Most eicosanoids act primarily on their respective cell surface G-protein coupled receptors to elicit downstream signaling in an autocrine and paracrine fashion. Emerging evidence indicates that these hormones are also critical in apoptosis in a cell/tissue specific manner. In this review, we summarize the formation of eicosanoids and their roles as mediators in apoptosis, specifically on the roles of mitochondria in mediating these events and the signaling pathways involved. The biological relevance of eicosanoid-mediated apoptosis is also discussed.

  2. The influence of supplemental docosahexaenoic and arachidonic acids during pregnancy and lactation on neurodevelopment at eighteen months

    NARCIS (Netherlands)

    van Goor, Saskia A.; Dijck-Brouwer, D. A. Janneke; Erwich, Jan Jaap H. M.; Schaafsma, Anne; Hadders-Algra, Mijna

    2011-01-01

    Docosahexaenoic acid (DHA) and arachidonic acid (AA) are important for neurodevelopment. The effects of DHA (220 mg/day, n=41), DHA+AA (220 mg/day, n=39) or placebo (n=34) during pregnancy and lactation on neurodevelopment at 18 months, and the relations between umbilical cord DHA, AA and Mead acid

  3. Endogenous biosynthesis of arachidonic acid epoxides in humans: Increased formation in pregnancy-induced hypertension

    Energy Technology Data Exchange (ETDEWEB)

    Catella, F.; Lawson, J.A.; Fitzgerald, D.J.; FitzGerald, G.A. (Vanderbilt Univ., Nashville, TN (USA))

    1990-08-01

    Arachidonic acid is metabolized by means of P450 isoenzyme(s) to form epoxyeicosatrienoic acids (EETs) and their corresponding dihydroxy derivatives (DHETs). In the present study, we established the presence in human urine of 8,9-, 11,12-, and 14,15-EETs and their corresponding DHETs by developing quantitative assays and using negative ion, chemical ionization GC/MS and octadeuterated internal standards. Urinary excretion of 8,9- and 11,12-DHET increased in healthy pregnant women compared with nonpregnant female volunteers. By contrast, excretion of 11,12-DHET and 14,15-DHET, but not the 8,9-DHET regioisomer, increased even further in patients with pregnancy-induced hypertension. Intravenous administration of (3H)14,15-EET to three dogs markedly increased its DHET in plasma. The terminal half-life ranged from 7.9-12.3 min and the volume of distribution (3.5-5.3 liters) suggested limited distribution outside the plasma compartment. Negligible radioactivity was detected in urine; this fact infers that under physiological circumstances, urinary DHETs largely derive from the kidney. That P450 metabolites of arachidonic acid are formed in humans supports the hypothesis that these metabolites contribute to the physiological response to normal pregnancy and the pathophysiology of pregnancy-induced hypertension.

  4. Obesity is positively associated with arachidonic acid-derived 5- and 11-hydroxyeicosatetraenoic acid (HETE).

    Science.gov (United States)

    Pickens, Charles Austin; Sordillo, Lorraine M; Zhang, Chen; Fenton, Jenifer I

    2017-05-01

    Oxylipids are oxygenated polyunsaturated fatty acid (PUFA) metabolites that are responsible for the onset and resolution of the inflammatory response. Enzymatic oxygenation through the lipoxygenase (LOX) or cytochrome P450 (CYP) pathways can form oxylipids that have either proinflammatory or proresolving functions depending on the type of PUFA substrate and degree of metabolism. The objective of this study was to determine how PUFA substrates and their corresponding oxylipids are associated with obesity. Plasma non-esterified FA and oxylipids were isolated from 123 Caucasian males using solid phase extraction and quantified using high performance liquid chromatography-tandem mass spectrometry. Statistical analyses included linear regressions and polytomous logistic regressions, and the responses were body mass index (BMI) and waist circumference (WC), and serum leptin, total adiponectin, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and C-peptide. Models were adjusted for age and smoking, and p-values were corrected for false discovery per Benjamini-Hochberg and Bonferroni. We report that BMI, WC, and several serum cytokines were highly associated arachidonic acid (ARA)-derived hydroxyeicosatetraenoic acids (HETEs), and vicinal diols (i.e., alcohols on adjacent carbon atoms) derived from several PUFAs. There was a significant linear relationship between BMI, WC, and serum leptin, and ARA-derived 5-, 11-, and 15-HETE. Specifically, BMI and WC were positively associated with proinflammatory 5- and 11-hydroxyeicosatetraenoic acid (HETE), even after normalization to ARA concentrations and false discovery p-value correction. Individuals with 5-HETE concentrations >5.01nmol/L or 11-HETE concentrations and >0.89nmol/L were over 5 times more likely to be obese compared to those with ≤1.86nmol/L and ≤0.39nmol/L, respectively. Vicinal diols from linoleic, eicosapentaenoic, and docosahexaenoic acid were inversely associated with obesity. Across all statistical

  5. Glycerol-3-phosphate acyltransferase-2 is expressed in spermatic germ cells and incorporates arachidonic acid into triacylglycerols.

    Directory of Open Access Journals (Sweden)

    Elizabeth R Cattaneo

    Full Text Available BACKGROUND: De novo glycerolipid synthesis begins with the acylation of glycerol-3 phosphate catalyzed by glycerol-3-phosphate acyltransferase (GPAT. In mammals, at least four GPAT isoforms have been described, differing in their cell and tissue locations and sensitivity to sulfhydryl reagents. In this work we show that mitochondrial GPAT2 overexpression in CHO-K1 cells increased TAG content and both GPAT and AGPAT activities 2-fold with arachidonoyl-CoA as a substrate, indicating specificity for this fatty acid. METHODS AND RESULTS: Incubation of GPAT2-transfected CHO-K1 cells with [1-(14C]arachidonate for 3 h increased incorporation of [(14C]arachidonate into TAG by 40%. Consistently, arachidonic acid was present in the TAG fraction of cells that overexpressed GPAT2, but not in control cells, corroborating GPAT2's role in synthesizing TAG that is rich in arachidonic acid. In rat and mouse testis, Gpat2 mRNA was expressed only in primary spermatocytes; the protein was also detected in late stages of spermatogenesis. During rat sexual maturation, both the testicular TAG content and the arachidonic acid content in the TAG fraction peaked at 30 d, matching the highest expression of Gpat2 mRNA and protein. CONCLUSIONS: These results strongly suggest that GPAT2 expression is linked to arachidonoyl-CoA incorporation into TAG in spermatogenic germ cells.

  6. [The role of arachidonic acid metabolites in the regulation of renal function and pathogenesis of hypertension].

    Science.gov (United States)

    Certíková Chábová, V

    2008-01-01

    Eicosanoids are twenty-carbon compounds derived from arachidonic acid. Lipoxygenases, cyclooxygenases and cytochrome P-450 enzymes contribute to their synthesis. Our review is focused on prostaglandins, leucotrienes, lipoxins, hepoxilins, hydroxyeicosatetraenoic acids, and epoxyeicosatrienoic acids. Most of these compounds have multiple functions and they also participate in blood pressure regulation and excretion of water and solutes in the kidney. They have some roles in the patogenesis of kidney disease, too. Both experimental models (mainly geneticaly modified mice and rats) and human epidemiological and genetical studies are used in the investigation of eicosanoid physiological and patophysiological functions. New information about their enzymatic regulations and receptors have already resulted in the development of new drugs, mainly antiasthmatics, but further investigation should bring about new results in the treatment of hypertension and other cardiovascular and renal diseases.

  7. Arachidonic and eicosapentaenoic acids in Araucariaceae, a unique feature among seed plants

    Directory of Open Access Journals (Sweden)

    Wolff Robert L.

    2000-01-01

    Full Text Available It is generally admitted that seed plants (spermaphytes are unable to synthesize either arachidonic or eicosapentaenoic acids (AA and EPA, the classic essential fatty acids in animals. We give here chromatographic and spectrometric data showing that species from the primitive family Araucariaceae (gymnosperms are able to synthesize AA and/or EPA in their seeds and leaves. Agathis robusta, in particular, contains AA and EPA in small amounts in its seeds, with no D5-unsaturated polymethylene-interrupted fatty acids (D5-UPIFA with 18 carbon atoms, whereas Araucaria spp. contain both AA and C18 D5-UPIFA. In both species, D5-UPIFA with 20 carbon atoms are present as in all other Coniferophytes. All metabolic intermediates necessary for the biosynthesis of AA and/or EPA have been characterized in Araucariaceae seeds. The relevance of these observations is discussed with regard to the phylogeny of Coniferophytes.

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

    Energy Technology Data Exchange (ETDEWEB)

    Gray, P.R.; Derksen, F.J.; Robinson, N.E.; Peter-Golden, M.L. (Michigan State Univ., East Lansing (United States) Univ. of Michigan, Ann Arbor (United States))

    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.

  9. The target of arachidonic acid pathway is a new anticancer strategy for human prostate cancer

    Directory of Open Access Journals (Sweden)

    Masahide Matsuyama

    2008-07-01

    Full Text Available Masahide Matsuyama, Rikio YoshimuraDepartment of Urology, Osaka City University Graduate School of Medicine, Osaka, JapanAbstract: Recent epidemiological studies and animal experiments have demonstrated that nonsteroidal anti-inflammatory drugs (NSAIDs reduce the incidence of colorectal carcinoma. Cyclooxygenase (COX is the principal target of NSAIDs. COX is the first oxidase in the process of prostaglandin production from arachidonic acid. COX enzyme may be involved in the initiation and/or the promotion of carcinogenesis due to NSAIDs inhibition of COX. Lipoxygenase (LOX is also an initial enzyme in the pathway for producing leukotrienes from arachidonic acid. Similar to COX, LOX enzyme may also be involved in the initiation and/or promotion of carcinogenesis. Peroxisome proliferator activator-receptor (PPAR-γ is a ligand-activated transcriptional factor belonging to the steroid receptor superfamily. PPAR-γ plays a role in both adipocyte differentiation and carcinogenesis. PPAR-γ is one target for cell growth modulation of NSAIDs. In this review, we report the expression of COX-2, LOX and PPAR-γ in human prostate cancer tissues as well as the effects of COX-2 and LOX inhibitors and PPAR-γ ligand.Keywords: cyclooxygenase, lipoxygenase, peroxisome proliferator activator-receptor-γ, prostate cancer

  10. Arachidonic acid metabolism in the platelets and neutrophils of diabetic rabbit and human subjects

    Energy Technology Data Exchange (ETDEWEB)

    Greco, N.J.

    1985-01-01

    An alteration of arachidonic acid metabolism to prostaglandins and leukotrienes from platelets and polymorphonuclear leukocytes respectively is evident in subjects with diabetes mellitus. There is evidence of altered platelet/vascular wall interactions in diabetes mellitus and evidence that polymorphonuclear leukocytes influence the vascular walls. Theories on the pathogenesis of atherosclerosis include both blood cells. Platelet hypersensitivity is evident in those platelets from the alloxan-induced diabetic rabbit either suspended in plasma or buffer. Arachidonic acid- and collagen-induced platelet aggregation, release of /sup 14/serotonin, and T x B/sub 2/ and 12-HETE production is enhanced when responses of diabetic platelets are compared to control platelets. Control rabbit neutrophils produce more LTB/sub 4/, LTB/sub 4/ isomers and 5-HETE than diabetic rabbits neutrophils. Decreased synthesis from diabetic rabbit neutrophils is not explained by increased catabolism of LTB/sub 4/, reesterification of 5-HETE, or increased eicosanoid formation. These experiments demonstrate both platelet and neutrophil dysfunction in diabetic subjects. Because of the involvement of these cells in regulating circulatory homeostatis, abnormal behavior could aggravate the atherosclerotic process. Platelet and neutrophil dysfunctions are noted before macroscopic vascular lesions are apparent suggesting an important role in the pathogenesis of atherosclerosis.

  11. Regulation of the arachidonic acid-stimulated respiratory burst in neutrophils by intra- cellular and extracellular calcium

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The respiratory burst is an important physiological function ofthe neutrophils in killing the bacteria invading in human body. We used chemiluminescence method to measure the exogenous arachidonic acid-stimulated respiratory burst, and measured the cytosolic free calcium concentration in neutrophils by the fluorescence method. It was found that, on one hand, the arachidonic acid-stimulated respiratory burst was enhanced by elevating the cytosolic free calcium concentration in neutrophils with a potent endomembrane Ca2+-ATPase inhibitor, Thapsgargin; on the other hand, chelating the intracellular or extracellular calcium by EGTA or BAPTA inhibited the respiratory burst. Results showed that calcium plays an important regulatory role in the signaling pathway involved in the exogenous arachidonic acid-stimulated respiratory burst of neutrophils.

  12. Inhibition by amiloride and by Na-depletion of A23187-stimulated arachidonic acid and histamine release from rat mast cells

    DEFF Research Database (Denmark)

    Linnebjerg, H.; Hansen, Harald S.; Jensen, B.

    1988-01-01

    Rat peritoneal mast cells, labelled with [C]arachidonic acid, released histamine and [C]arachidonic acid upon the addition of A23187. The release induced by low concentrations of A23187 was suppressed by removal of extracellular Na and by addition of the Na/H exchange inhibitor, amiloride. Addition...

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

    Science.gov (United States)

    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.

  14. Modulation of arachidonic and linoleic acid metabolites in myeloperoxidase deficient mice during acute inflammation

    Science.gov (United States)

    Kubala, Lukas; Schmelzer, Kara R.; Klinke, Anna; Kolarova, Hana; Baldus, Stephan; Hammock, Bruce D.; Eiserich, Jason P.

    2010-01-01

    Acute inflammation is a common feature of many life-threatening pathologies, including septic shock. One hallmark of acute inflammation is the peroxidation of polyunsaturated fatty acids forming bioactive products, which regulate inflammation. Myeloperoxidase (MPO) is an abundant phagocyte-derived hemoprotein released during phagocyte activation. Here, we investigated the role of MPO in modulating biologically active arachidonic acid (AA) and linoleic acid (LA) metabolites during acute inflammation. Wild-type and MPO-knockout (KO) mice were exposed to intraperitoneally injected endotoxin for 24 h, and plasma LA and AA oxidation products were comprehensively analyzed using a liquid chromatography-mass spectrometry method. Compared to wild-type mice, MPO-KO mice had significantly lower plasma levels of LA epoxides and corresponding LA- and AA-derived fatty acid diols. AA and LA hydroxy intermediates (hydroxyeicosatetraenoic and hydroxyoctadecadienoic acids) were also significantly lower in MPO-KO mice. Conversely, MPO-deficient mice had significantly higher plasma levels of cysteinyl-leukotrienes with well-known pro-inflammatory properties. In vitro experiments revealed significantly lower amounts of AA and LA epoxides, LA- and AA-derived fatty acid diols, and AA and LA hydroxy intermediates in stimulated polymorphonuclear neutrophils isolated from MPO-KO mice. Our results demonstrate that MPO modulates the balance of pro- and anti-inflammatory lipid mediators during acute inflammation. In this way, may control acute inflammatory diseases. PMID:20156554

  15. Chronic Arachidonic Acid Administration Decreases Docosahexaenoic Acid- and Eicosapentaenoic Acid-Derived Metabolites in Kidneys of Aged Rats.

    Directory of Open Access Journals (Sweden)

    Masanori Katakura

    Full Text Available Arachidonic acid (ARA metabolites produced by cyclo-oxygenase and lipoxygenase are important mediators maintaining physiological renal function. However, the effects of exogenous ARA on kidney function in vivo remain unknown. This study examined the effects of long-term oral ARA administration on normal renal function as well as inflammation and oxidative stress in aged rats. In addition, we measured levels of renal eicosanoids and docosanoids using liquid chromatography-tandem mass spectrometry. Control or ARA oil (240 mg/kg body weight/day was orally administered to 21-month-old Wistar rats for 13 weeks. Levels of plasma creatinine, blood urea nitrogen, inflammatory and anti-inflammatory cytokines, reactive oxygen species, and lipid peroxidation were not significantly different between the two groups. The ARA concentration in the plasma, kidney, and liver increased in the ARA-administered group. In addition, levels of free-form ARA, prostaglandin E2, and 12- and 15-hydroxyeicosatetraenoic acid increased in the ARA-administered group, whereas renal concentration of docosahexaenoic acid and eicosapentaenoic acid decreased in the ARA-administered group. Levels of docosahexaenoic acid-derived protectin D1, eicosapentaenoic acid-derived 5-, and 18-hydroxyeicosapentaenoic acids, and resolvin E2 and E3 decreased in the ARA-administered group. Our results indicate that long-term ARA administration led to no serious adverse reactions under normal conditions and to a decrease in anti-inflammatory docosahexaenoic acid- and eicosapentaenoic acid-derived metabolites in the kidneys of aged rats. These results indicate that there is a possibility of ARA administration having a reducing anti-inflammatory effect on the kidney.

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

    Directory of Open Access Journals (Sweden)

    Carlos Rodrigo Camara-Lemarroy

    2012-01-01

    Full Text Available 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.

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

    Science.gov (United States)

    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

  18. Ozone toxicity: hormone-like oxidation products from arachidonic acid by ozone-catalyzed autoxidation

    Energy Technology Data Exchange (ETDEWEB)

    Roycroft, J.H.; Cunter, W.B.; Menzel, D.B.

    1977-09-01

    The effects of peroxidation by ozone on the activity of arachidonic acid (AA) with and without vitamin E, on the initiation of human platelet aggregation, and on the contraction of superfused smooth muscle strips, are described. AA was rapidly oxidized by a stream of air containing 2 ppm of ozone to peroxides having biological activity similar to prostaglandin endoperoxides. Ozone-formed AA peroxides contracted both rabbit aortic strips and rat fundus strips in the presence of indomethacin and vasoactive hormones at doses comparable to naturally formed prostaglandin endoperoxides. Vitamin E had no effect on the activity of AA peroxides once formed. Ozone-formed AA peroxides also aggregated human platelets in platelet rich plasma, but this activity was blocked by the addition of indomethacin. (2 diagrams, 3 graphs, 8 references)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

  1. Arachidonic acid modulates hippocampal calcium current via protein kinase C and oxygen radicals.

    Science.gov (United States)

    Keyser, D O; Alger, B E

    1990-10-01

    Arachidonic acid (AA) is a second messenger liberated via receptor activation of phospholipase A2 or diacylglycerol-lipase. We used whole-cell voltage clamp of acutely isolated hippocampal CA1 pyramidal cells to investigate the hypothesis that AA modulates Ca2+ channel current (ICa) via activation of protein kinase C (PKC) and generation of free radicals. AA depressed ICa in a dose- and time-dependent manner similar to that previously reported for the action of phorbol esters on ICa. A similar depression was seen with a xanthine-based free radical generating system. The specific PKC inhibitor PKCI (19-36), the protein kinase inhibitor H-7, and the superoxide free radical scavenger SOD each blocked ICa depression by 70%-80%. Complete block of the AA response occurred when SOD was used simultaneously with a PKC inhibitor. These data suggest that PKC and free radicals play a role in AA-induced suppression of ICa.

  2. Pulmonary arachidonic acid metabolism following acute exposures to ozone and nitrogen dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Schlesinger, R.B.; Driscoll, K.E.; Gunnison, A.F.; Zelikoff, J.T. (New York Univ. Medical Center, NY (USA))

    1990-12-01

    Ozone (O{sub 3}) and nitrogen dioxide (NO{sub 2}) are common air pollutants, and exposure to these gases has been shown to affect pulmonary physiology, biochemistry, and structure. This study examined their ability to modulate arachidonic acid metabolites (eicosanoids) in the lungs. Rabbits were exposed for 2 h to O{sub 3} at 0.1, 0.3, or 1 ppm; NO{sub 2} at 1, 3, or 10 ppm; or to a mixture of 0.3 ppm O{sub 3} and 3 ppm NO{sub 2}. Groups of animals sacrificed either immediately or 24 h after each exposure underwent broncho-pulmonary lavage. Selected eicosanoids were assessed in lavage fluid by radioimmunoassay. Increases in prostaglandins E2 (PGE2) and F2 alpha (PGF2 alpha) were found immediately after exposure to 1 ppm O{sub 3}. Exposure to 10 ppm NO{sub 2} resulted in a depression of 6-keto-PGF1 alpha, while thromboxane B2 (TxB2) was elevated after exposure to 1 ppm NO{sub 2} and depressed following 3 and 10 ppm. The O{sub 3}/NO{sub 2} mixture resulted in synergistic increases in PGE2 and PGF2 alpha, with the response appearing to be driven by O{sub 3}. This study has demonstrated that acute exposure to either O{sub 3} or NO{sub 2} can alter pulmonary arachidonic acid metabolism and that the responses to these oxidants differ, both quantitatively and qualitatively.

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

    Science.gov (United States)

    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.

  4. Polymorphisms in the genes involved in the arachidonic acid-pathway, fish consumption and the risk of colorectal cancer.

    NARCIS (Netherlands)

    Siezen, Christine L E; Bueno-de-Mesquita, H Bas; Peeters, Petra H M; Kram, Nicolien R; Doeselaar, Marina van; Kranen, Henk J van

    2006-01-01

    The objective of this study on colorectal cancer was to investigate the associations between SNPs in the genes involved in the arachidonic acid (AA)-pathway, their haplotypes and colorectal cancer. Moreover, interactions between SNPs and fish consumption were considered. In this study, a total of 50

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

    Science.gov (United States)

    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 Violet low) 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.

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

    Science.gov (United States)

    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

  7. Calcium-dependent phospholipid catabolism and arachidonic acid mobilization in cerebral minces

    Energy Technology Data Exchange (ETDEWEB)

    Damron, D.S.; Dorman, R.V. (Kent State Univ., OH (USA))

    1990-06-01

    Cerebral minces were used to investigate the role of calcium influx on trauma-induced alterations of brain lipid metabolism. Cerebral phospholipids, nonpolar lipids, and free fatty acids were radiolabeled in vivo with ({sup 3}H)arachidonic acid. Tissue incubation stimulated the time-dependent catabolism of choline and inositol glycerophospholipids, and resulted in the accumulation of ({sup 3}H)free fatty acids. These effects were attenuated in Ca{sup 2}{sup +}-free incubations, and when EGTA or verapamil were present. The inhibition of calcium influx also reduced the labeling of diglycerides, whereas ethanolamine and serine glycerophospholipids were not affected by incubation or treatments. Replacing Ca{sup 2}{sup +} with other cations also attenuated the incubation-dependent alterations in lipid metabolism. However, only cadmium was able to compete with calcium and reduce the accumulation of ({sup 3}H)free fatty acids. It appeared that about half of the observed phospholipid catabolism was dependent on Ca{sup 2}{sup +} influx and that at least 80% of the ({sup 3}H)free fatty acid accumulation required calcium.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  10. IMAGING BRAIN SIGNAL TRANSDUCTION AND METABOLISM VIA ARACHIDONIC AND DOCOSAHEXAENOIC ACID IN ANIMALS AND HUMANS

    Science.gov (United States)

    Basselin, Mireille; Ramadan, Epolia; Rapoport, Stanley I.

    2012-01-01

    The polyunsaturated fatty acids (PUFAs), arachidonic acid (AA, 20:4n-6) and docosahexaenoic acid (DHA, 22:6n-3), important second messengers in brain, are released from membrane phospholipid following receptor-mediated activation of specific phospholipase A2 (PLA2) enzymes. We developed an in vivo method in rodents using quantitative autoradiography to image PUFA incorporation into brain from plasma, and showed that their incorporation rates equal their rates of metabolic consumption by brain. Thus, quantitative imaging of unesterified plasma AA or DHA incorporation into brain can be used as a biomarker of brain PUFA metabolism and neurotransmission. We have employed our method to image and quantify effects of mood stabilizers on brain AA/DHA incorporation during neurotransmission by muscarinic M1,3,5, serotonergic 5-HT2A/2C, dopaminergic D2-like (D2, D3, D4) or glutamatergic N-methyl-D-aspartic acid (NMDA) receptors, and effects of inhibition of acetylcholinesterase, of selective serotonin and dopamine reuptake transporter inhibitors, of neuroinflammation (HIV-1 and lipopolysaccharide) and excitotoxicity, and in genetically modified rodents. The method has been extended for the use with positron emission tomography (PET), and can be employed to determine how human brain AA/DHA signaling and consumption are influenced by diet, aging, disease and genetics. PMID:22178644

  11. Lipid characterization of an arachidonic acid-rich oil producing fungus Mortierella alpina

    Institute of Scientific and Technical Information of China (English)

    Wenjia Wu; Jiacheng Yan; Xiaojun Ji; Xin Zhang; Jingsheng Shang; Lina Sun; Lujing Ren; He Huang

    2015-01-01

    Mortierel a alpina has been considered as the most effective producer of arachidonic acid (ARA)-rich oil. It was found that several methods could improve the percentage of ARA in total lipids successful y, as they activated the desaturation system on the endoplasmic reticulum. Additionally, in M. alpina the ARA exists in several forms, such as triacylglycerol (TAG), and diacylglycerol (DAG). These forms are caused by different acyltransferases and they determine the nutrient value of the microbial oil. However, few works revealed de-tailed fatty acid distribution among lipid classes, which to some extent impeded the accurate regulation in ARA accumulation. Herein, this paper gives information on the accumulation process of main lipid classes and the changes of fatty acid composition in these lipids during ARA accumulation period in M. alpina. The result dem-onstrates that TAG was the dominant component of the total lipids, and it is the main form for ARA storage. The ARA enrichment stage occurred during 168–192 h when the amount of total lipids maintained steady. Further analysis indicated that the newly formed ARA-TAG might come from the incorporation and modification of sat-urated and monounsaturated fatty acids in other lipid classes. This work could be helpful for further optimization of ARA-rich TAG production.

  12. Synergy by secretory phospholipase A2 and glutamate on inducing cell death and sustained arachidonic acid metabolic changes in primary cortical neuronal cultures

    DEFF Research Database (Denmark)

    Kolko, M; DeCoster, M A; de Turco, E B

    1996-01-01

    Secretory and cytosolic phospholipases A2 (sPLA2 and cPLA2) may contribute to the release of arachidonic acid and other bioactive lipids, which are modulators of synaptic function. In primary cortical neuron cultures, neurotoxic cell death and [3H]arachidonate metabolism was studied after adding ...

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

    Science.gov (United States)

    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.

  14. Ethanolic extract of Piper betle Linn. leaves reduces nociception via modulation of arachidonic acid pathway

    Directory of Open Access Journals (Sweden)

    Soumita De

    2013-01-01

    Full Text Available Objectives: The objective of this study was to evaluate the peripheral analgesic effect of Piper betle leaf extract (PBE along with establishing its putative mechanism of action. Materials and Methods: Male Swiss albino mice after pre-treatment (1 h with different doses of PBE were injected 0.8% (v/v acetic acid i.p.; the onset and number of writhes were noted up to 15 min. To evaluate the mechanism of action, the murine peritoneal exudate was incubated with PBE for 1 h, followed by exposure to arachidonic acid (AA and generation of reactive oxygen species (ROS was measured by flow cytometry using 2′,7′-dichlorodihydrofluorescein diacetate. Results: PBE in a dose dependent manner significantly reduced acetic acid induced writhing response in mice (P < 0.001. In peritoneal exudates, PBE significantly inhibited AA induced generation of ROS, P < 0.01. Conclusions: The present study indicates that PBE has promising analgesic activity, worthy of future pharmacological consideration.

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

    Science.gov (United States)

    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.

  16. Effects of organometals on cellular signaling. I. Influence of metabolic inhibitors on metal-induced arachidonic acid liberation.

    OpenAIRE

    1994-01-01

    Organic lead and tin compounds stimulate an increase of free arachidonic acid (AA) in HL-60 cells. This fatty acid is involved in numerous health problems and physiological mechanisms. Three major pathways result in a liberation of AA from membrane phospholipids and there is evidence that G-proteins serve as couplers within all three pathways. Therefore we investigated the influence of pertussis toxin (PT) on the organometallic-induced AA liberation. The effect of all studied compounds (organ...

  17. The effect of reactive oxygen species on the synthesis of prostanoids from arachidonic acid.

    Science.gov (United States)

    Korbecki, J; Baranowska-Bosiacka, I; Gutowska, I; Chlubek, D

    2013-08-01

    Reactive oxygen species (ROS), such as hydrogen peroxide, superoxide anion radical or hydroxyl radical, play an important role in inflammation processes as well as in transduction of signals from receptors to interleukin -1β (IL-1β), tumor necrosis factor α (TNF-α) or lipopolysaccharides (LPS). NADPH oxidase increases the ROS levels, leading to inactivation of protein phosphatase 1 (PP1), protein phosphatase 2A (PP2A) and protein tyrosine phosphatase (PTP): MAPK phosphatase 1 (MKP-1). Inactivation of phosphatases results in activation of mitogen-activated protein kinase (MAPK) cascades: c-Jun N-terminal kinase (JNK), p38 and extracellular signal-regulated kinase (Erk), which, in turn, activate cytosolic phospholipase A₂ (cPLA₂). ROS cause cytoplasmic calcium influx by activation of phospholipase C (PLC) and phosphorylation of IP₃-sensitive calcium channels. ROS activate nuclear factor κB (NF-κB) via IκB kinase (IKK) through phosphoinositide 3-kinase (PI3K), tumor suppressor phosphatase and tensin homolog (PTEN) and protein kinase B (Akt/PKB) or NF-κB-inducing kinase (NIK). IKK phosphorylates NF-κB α subunit (IκBα) at Ser³². Oxidative stress inactivates NIK and IκB kinase γ subunit/NF-κB essential modulator (IKKγ/NEMO), which might cause activation of NF-κB that is independent on IKK and inhibitor of IκBα degradation, including phosphorylation of Tyr⁴² at IκBα by c-Src and spleen tyrosine kinase (Syk), phosphorylation of the domain rich in proline, glutamic acid, serine and threonine (PEST) sequence by casein kinase II and inactivation of protein tyrosine phosphatase 1B (PTP1B). NF-κB and MAPK cascades-activated transcription factor activator protein 1 (AP-1) and CREB-binding protein (CBP/p300) lead to expression of cytosolic phospholipase A₂ (cPLA₂), cyclooxygenase-2 (COX-2) and membrane-bound prostaglandin E synthase 1 (mPGES-1), and thus to increased release of arachidonic acid and production of prostaglandins, particularly

  18. Cell survival signalling through PPARδ and arachidonic acid metabolites in neuroblastoma.

    Directory of Open Access Journals (Sweden)

    Emma Bell

    Full Text Available Retinoic acid (RA has paradoxical effects on cancer cells: promoting cell death, differentiation and cell cycle arrest, or cell survival and proliferation. Arachidonic acid (AA release occurs in response to RA treatment and, therefore, AA and its downstream metabolites may be involved in cell survival signalling. To test this, we inhibited phospholipase A2-mediated AA release, cyclooxygenases and lipoxygenases with small-molecule inhibitors to determine if this would sensitise cells to cell death after RA treatment. The data suggest that, in response to RA, phospholipase A2-mediated release of AA and subsequent metabolism by lipoxygenases is important for cell survival. Evidence from gene expression reporter assays and PPARδ knockdown suggests that lipoxygenase metabolites activate PPARδ. The involvement of PPARδ in cell survival is supported by results of experiments with the PPARδ inhibitor GSK0660 and siRNA-mediated knockdown. Quantitative reverse transcriptase PCR studies demonstrated that inhibition of 5-lipoxygenase after RA treatment resulted in a strong up-regulation of mRNA for PPARδ2, a putative inhibitory PPARδ isoform. Over-expression of PPARδ2 using a tetracycline-inducible system in neuroblastoma cells reduced proliferation and induced cell death. These data provide evidence linking lipoxygenases and PPARδ in a cell survival-signalling mechanism and suggest new drug-development targets for malignant and hyper-proliferative diseases.

  19. Development of a defined medium for arachidonic acid production by Mortierella alpina using a visualization method.

    Science.gov (United States)

    Liu, Xin; Ji, Xiaojun; Zhang, Hongman; Fu, Ninghua; Yan, Liexiang; Deng, Zhongtao; Huang, He

    2012-11-01

    Defined medium for arachidonic acid (ARA) production by Mortierella alpina was optimized for its metabolomics study. For this purpose, a visualization method (VM) was applied for the first time. Experiments were designed according to the uniform design with four factors (concentrations of glucose, NaNO(3), KH(2)PO(4) and MgSO(4)·7H(2)O) for each at nine levels. Dry cell weight (DCW), ARA yield in DCW [percent (w/w)] and ARA content in total fatty acids [percent (w/w)] were considered as the three objectives. Optimization of single-objective function and multi-objective function of two objectives and three objectives was attempted. Optimal DCW, ARA yield and ARA content were predicted to occur in a medium that contained (grams per litre): glucose 35, NaNO(3) 1, KH(2)PO(4) 7.5 and MgSO(4)·7H(2)O 2.6. Upon verification, the average tested DCW (12.95 g/l), ARA yield (18.89 %) and ARA content (42.36 %) were fairly close to the predicted values (12.88 g/l, 9.68 % and 35.57 %, respectively). Moreover, DCW, ARA yield and ARA content from the optimum medium increased by 35.68, 47.23 and 30.90 % compared with control, respectively, indicating that VM had succeeded in exploiting the biomass growth and ARA production by M. alpina.

  20. 2-hydroxy arachidonic acid: a new non-steroidal anti-inflammatory drug.

    Directory of Open Access Journals (Sweden)

    Daniel H Lopez

    Full Text Available BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs are a family of COX1 and COX2 inhibitors used to reduce the synthesis of pro-inflammatory mediators. In addition, inflammation often leads to a harmful generation of nitric oxide. Efforts are being done in discovering safer NSAIDs molecules capable of inhibiting the synthesis of pro-inflammatory lipid mediators and nitric oxide to reduce the side effects associated with long term therapies. METHODOLOGY/PRINCIPAL FINDINGS: The analogue of arachidonic acid (AA, 2-hydroxy-arachidonic acid (2OAA, was designed to inhibit the activities of COX1 and COX2 and it was predicted to have similar binding energies as AA for the catalytic sites of COX1 and COX2. The interaction of AA and 2OAA with COX1 and COX2 was investigated calculating the free energy of binding and the Fukui function. Toxicity was determined in mouse microglial BV-2 cells. COX1 and COX2 (PGH2 production activities were measured in vitro. COX1 and COX2 expression in human macrophage-like U937 cells were carried out by Western blot, immunocytochemistry and RT-PCR analysis. NO production (Griess method and iNOS (Western blot were determined in mouse microglial BV-2 cells. The comparative efficacy of 2OAA, ibuprofen and cortisone in lowering TNF-α serum levels was determined in C57BL6/J mice challenged with LPS. We show that the presence of the -OH group reduces the likelihood of 2OAA being subjected to H* abstraction in COX, without altering significantly the free energy of binding. The 2OAA inhibited COX1 and COX2 activities and the expression of COX2 in human U937 derived macrophages challenged with LPS. In addition, 2OAA inhibited iNOS expression and the production of NO in BV-2 microglial cells. Finally, oral administration of 2OAA decreased the plasma TNF-α levels in vivo. CONCLUSION/SIGNIFICANCE: These findings demonstrate the potential of 2OAA as a NSAID.

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

    Science.gov (United States)

    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.

  2. Human prefrontal cortex phospholipids containing docosahexaenoic acid increase during normal adult aging, whereas those containing arachidonic acid decrease.

    Science.gov (United States)

    Norris, Sarah E; Friedrich, Michael G; Mitchell, Todd W; Truscott, Roger J W; Else, Paul L

    2015-04-01

    Membrane phospholipids make up a substantial portion of the human brain, and changes in their amount and composition are thought to play a role in the pathogenesis of age-related neurodegenerative disease. Nevertheless, little is known about the changes that phospholipids undergo during normal adult aging. This study examined changes in phospholipid composition in the mitochondrial and microsomal membranes of human dorsolateral prefrontal cortex over the adult life span. The largest age-related changes were an increase in the abundance of both mitochondrial and microsomal phosphatidylserine 18:0_22:6 by approximately one-third from age 20 to 100 years and a 25% decrease in mitochondrial phosphatidylethanolamine 18:0_20:4. Generally, increases were seen with age in phospholipids containing docosahexaenoic acid across both membrane fractions, whereas phospholipids containing either arachidonic or adrenic acid decreased with age. These findings suggest a gradual change in membrane lipid composition over the adult life span.

  3. Arachidonic and oleic acid exert distinct effects on the DNA methylome

    Science.gov (United States)

    Silva-Martínez, Guillermo A.; Rodríguez-Ríos, Dalia; Alvarado-Caudillo, Yolanda; Vaquero, Alejandro; Esteller, Manel; Carmona, F. Javier; Moran, Sebastian; Nielsen, Finn C.; Wickström-Lindholm, Marie; Wrobel, Katarzyna; Wrobel, Kazimierz; Barbosa-Sabanero, Gloria; Zaina, Silvio; Lund, Gertrud

    2016-01-01

    ABSTRACT Abnormal fatty acid metabolism and availability are landmarks of metabolic diseases, which in turn are associated with aberrant DNA methylation profiles. To understand the role of fatty acids in disease epigenetics, we sought DNA methylation profiles specifically induced by arachidonic (AA) or oleic acid (OA) in cultured cells and compared those with published profiles of normal and diseased tissues. THP-1 monocytes were stimulated with AA or OA and analyzed using Infinium HumanMethylation450 BeadChip (Illumina) and Human Exon 1.0 ST array (Affymetrix). Data were corroborated in mouse embryonic fibroblasts. Comparisons with publicly available data were conducted by standard bioinformatics. AA and OA elicited a complex response marked by a general DNA hypermethylation and hypomethylation in the 1–200 μM range, respectively, with a maximal differential response at the 100 μM dose. The divergent response to AA and OA was prominent within the gene body of target genes, where it correlated positively with transcription. AA-induced DNA methylation profiles were similar to the corresponding profiles described for palmitic acid, atherosclerosis, diabetes, obesity, and autism, but relatively dissimilar from OA-induced profiles. Furthermore, human atherosclerosis grade-associated DNA methylation profiles were significantly enriched in AA-induced profiles. Biochemical evidence pointed to β-oxidation, PPAR-α, and sirtuin 1 as important mediators of AA-induced DNA methylation changes. In conclusion, AA and OA exert distinct effects on the DNA methylome. The observation that AA may contribute to shape the epigenome of important metabolic diseases, supports and expands current diet-based therapeutic and preventive efforts. PMID:27088456

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

    Science.gov (United States)

    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.

  5. The effects of anaerobic training in serum lipids and arachidonic acid metabolites

    Directory of Open Access Journals (Sweden)

    GEORGIOS KIPREOS

    2010-01-01

    Full Text Available Coronary arteries are subjected daily in high shear stress and manifest atherosclerosis very early in life in comparison to other arteries in the human body. Some factors that are implicated in the evolution and progress of this process are the concentration of lipids and arachidonic acid metabolites, such prostacyclin and thromboxane. It has been reported that those who participate in aerobic activities such as walking, cycling, jogging or brisk walking might have normal values of the mentioned chemical substances. On the other hand, it is reported that the effects of anaerobic and strength activities has negative effects on the vascular endothelium, which is essential for the maintenance of hemostatic balance and the local regulation of vascular tone.Therefore, even although extensive research has been conducted in this field, there are crucial gaps in our knowledge. Consequently, the purpose of this brief review is to describe what is known about the effects of anaerobic activities in which the competitive athletes have participated on the following blood parameters: Total cholesterol, triglycerides, high density lipoprotein cholesterol (HDL - C, low density lipoproteins cholesterol (LDL - C, prostacyclin & thromboxane.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    Luca; Munaron

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Dormant 5-lipoxygenase in inflammatory macrophages is triggered by exogenous arachidonic acid.

    Science.gov (United States)

    Sorgi, Carlos A; Zarini, Simona; Martin, Sarah A; Sanchez, Raphael L; Scandiuzzi, Rodrigo F; Gijón, Miguel A; Guijas, Carlos; Flamand, Nicolas; Murphy, Robert C; Faccioli, Lucia H

    2017-09-08

    The differentiation of resident tissue macrophages from embryonic precursors and that of inflammatory macrophages from bone marrow cells leads to macrophage heterogeneity. Further plasticity is displayed through their ability to be polarized as subtypes M1 and M2 in a cell culture microenvironment. However, the detailed regulation of eicosanoid production and its involvement in macrophage biology remains unclear. Using a lipidomics approach, we demonstrated that eicosanoid production profiles between bone marrow-derived (BMDM) and peritoneal macrophages differed drastically. In polarized BMDMs, M1 and M2 phenotypes were distinguished by thromboxane B2, prostaglandin (PG) E2, and PGD2 production, in addition to lysophospholipid acyltransferase activity. Although Alox5 expression and the presence of 5-lipoxygenase (5-LO) protein in BMDMs was observed, the absence of leukotrienes production reflected an impairment in 5-LO activity, which could be triggered by addition of exogenous arachidonic acid (AA). The BMDM 5-LO regulatory mechanism was not responsive to PGE2/cAMP pathway modulation; however, treatment to reduce glutathione peroxidase activity increased 5-LO metabolite production after AA stimulation. Understanding the relationship between the eicosanoids pathway and macrophage biology may offer novel strategies for macrophage-associated disease therapy.

  11. Repurposing Resveratrol and Fluconazole To Modulate Human Cytochrome P450-Mediated Arachidonic Acid Metabolism.

    Science.gov (United States)

    El-Sherbeni, Ahmed A; El-Kadi, Ayman O S

    2016-04-04

    Cytochrome P450 (P450) enzymes metabolize arachidonic acid (AA) to several biologically active epoxyeicosatrienoic acids (EETs) and hydroxyeicosatetraenoic acids (HETEs). Repurposing clinically-approved drugs could provide safe and readily available means to control EETs and HETEs levels in humans. Our aim was to determine how to significantly and selectively modulate P450-AA metabolism in humans by clinically-approved drugs. Liquid chromatography-mass spectrometry was used to determine the formation of 15 AA metabolites by human recombinant P450 enzymes, as well as human liver and kidney microsomes. CYP2C19 showed the highest EET-forming activity, while CYP1B1 and CYP2C8 showed the highest midchain HETE-forming activities. CYP1A1 and CYP4 showed the highest subterminal- and 20-HETE-forming activity, respectively. Resveratrol and fluconazole produced the most selective and significant modulation of hepatic P450-AA metabolism, comparable to investigational agents. Monte Carlo simulations showed that 90% of human population would experience a decrease by 6-22%, 16-39%, and 16-35% in 16-, 18-, and 20-HETE formation, respectively, after 2.5 g daily of resveratrol, and by 22-31% and 14-23% in 8,9- and 14,15-EET formation after 50 mg of fluconazole. In conclusion, clinically-approved drugs can provide selective and effective means to modulate P450-AA metabolism, comparable to investigational drugs. Resveratrol and fluconazole are good candidates to be repurposed as new P450-based treatments.

  12. Arachidonic acid incorporation and turnover is decreased in sympathetically denervated rat heart.

    Science.gov (United States)

    Patrick, Casey B; McHowat, Jane; Rosenberger, Thad A; Rapoport, Stanley I; Murphy, Eric J

    2005-06-01

    Heart sympathetic denervation can accompany Parkinson's disease, but the effect of this denervation on cardiac lipid-mediated signaling is unknown. To address this issue, rats were sympathetically denervated with 6-hydroxydopamine (6-OHDA, 50 mg/kg ip) and infused with 170 muCi/kg of either [1-(14)C]palmitic acid ([1-(14)C]16:0) or [1-(14)C]arachidonic acid ([1-(14)C]20:4 n-6), and kinetic parameters were assessed using a steady-state radiotracer model. Heart norepinephrine and epinephrine levels were decreased 82 and 85%, respectively, in denervated rats, and this correlated with a 34% reduction in weight gain in treated rats. Fatty acid tracer uptake was not significantly different between groups for either tracer, although the dilution coefficient lambda was increased in [1-(14)C]20:4 n-6-infused rats, which indicates that less 20:4 n-6 was recycled in denervated rats. In [1-(14)C]16:0-infused rats, incorporation rate and turnover values of 16:0 in stable lipid compartments were unchanged, which is indicative of preservation of beta-oxidation. In [1-(14)C]20:4 n-6-infused rats, there were dramatic reductions in incorporation rate (60-84%) and turnover value (56-85%) in denervated rats that were dependent upon the lipid compartment. In addition, phospholipase A(2) activity was reduced 40% in treated rats, which is consistent with the reduction observed in 20:4 n-6 turnover. These results demonstrate marked reductions in 20:4 n-6 incorporation rate and turnover in sympathetic denervated rats and thereby suggest an effect on lipid-mediated signal transduction mediated by a reduction in phospholipase A(2) activity.

  13. Phospholipid, arachidonate and eicosanoid signaling in schizophrenia

    OpenAIRE

    Messamore Erik; Yao Jeffrey K.

    2016-01-01

    This paper reviews the potential role of arachidonic acid in the pathophysiology of schizophrenia. We discuss how abnormal levels of arachidonic acid may arise, and how dysregulation of signaling molecules derived from it have the potential to disrupt not only dopamine signaling, but numerous other physiological processes associated with the illness. Pharmacological doses of niacin stimulate the release of arachidonic acid; and arachidonic acid-derived molecules in turn dilate blood vessels i...

  14. Protective effects of arachidonic acid against palmitic acid-mediated lipotoxicity in HIT-T15 cells.

    Science.gov (United States)

    Cho, Young Sik; Kim, Chi Hyun; Kim, Ki Young; Cheon, Hyae Gyeong

    2012-05-01

    Saturated fatty acids have been considered major contributing factors in type 2 diabetes, whereas unsaturated fatty acids have beneficial effects for preventing the development of diabetes. However, the effects of polyunsaturated fatty acids in pancreatic β cells have not been reported. Here, we examined the effects of arachidonic acid (AA) on palmitic acid (PA)-mediated lipotoxicity in clonal HIT-T15 pancreatic β cells. AA prevented the PA-induced lipotoxicity as indicated by cell viability, DNA fragmentation and mitochondrial membrane potential, whereas eicosatetraynoic acid (ETYA), a non-metabolizable AA, had little effect on PA-induced lipotoxicity. In parallel with its protective effects against PA-induced lipotoxicity, AA restored impaired insulin expression and secretion induced by PA. AA but not ETYA increased intracellular triglyceride (TG) in the presence of PA compared with PA alone, and xanthohumol, a diacylglycerol acyltransferase (DGAT) inhibitor, reversed AA-induced protection from PA. Taken together, our results suggest that AA protects against PA-induced lipotoxicity in clonal HIT-T15 pancreatic β cells, and the protective effects may be associated with TG accumulation, possibly through sequestration of lipotoxic PA into TG.

  15. Improved mitochondrial function with diet-induced increase in either docosahexaenoic acid or arachidonic acid in membrane phospholipids.

    Directory of Open Access Journals (Sweden)

    Ramzi J Khairallah

    Full Text Available Mitochondria can depolarize and trigger cell death through the opening of the mitochondrial permeability transition pore (MPTP. We recently showed that an increase in the long chain n3 polyunsaturated fatty acids (PUFA docosahexaenoic acid (DHA; 22:6n3 and depletion of the n6 PUFA arachidonic acid (ARA; 20:4n6 in mitochondrial membranes is associated with a greater Ca(2+ load required to induce MPTP opening. Here we manipulated mitochondrial phospholipid composition by supplementing the diet with DHA, ARA or combined DHA+ARA in rats for 10 weeks. There were no effects on cardiac function, or respiration of isolated mitochondria. Analysis of mitochondrial phospholipids showed DHA supplementation increased DHA and displaced ARA in mitochondrial membranes, while supplementation with ARA or DHA+ARA increased ARA and depleted linoleic acid (18:2n6. Phospholipid analysis revealed a similar pattern, particularly in cardiolipin. Tetralinoleoyl cardiolipin was depleted by 80% with ARA or DHA+ARA supplementation, with linoleic acid side chains replaced by ARA. Both the DHA and ARA groups had delayed Ca(2+-induced MPTP opening, but the DHA+ARA group was similar to the control diet. In conclusion, alterations in mitochondria membrane phospholipid fatty acid composition caused by dietary DHA or ARA was associated with a greater cumulative Ca(2+ load required to induced MPTP opening. Further, high levels of tetralinoleoyl cardiolipin were not essential for normal mitochondrial function if replaced with very-long chain n3 or n6 PUFAs.

  16. 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.

    Science.gov (United States)

    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.

  17. Supplementation of DHA but not DHA with arachidonic acid during pregnancy and lactation influences general movement quality in 12-week-old term infants

    NARCIS (Netherlands)

    van Goor, Saskia A.; Dijck-Brouwer, D. A. Janneke; Doornbos, Bennard; Erwich, Jan Jaap H. M.; Schaafsma, Anne; Muskiet, Frits A. J.; Hadders-Algra, Mijna

    2010-01-01

    DHA and arachidonic acid (AA) are important for neurodevelopment. A traditional neonatal neurological examination and the evaluation of general movement quality are sensitive techniques for assessing neurodevelopment in young infants. Mildly abnormal general movement,,; at 3 months have been associa

  18. 2,3-Diarylxanthones as Potential Inhibitors of Arachidonic Acid Metabolic Pathways.

    Science.gov (United States)

    Santos, Clementina M M; Ribeiro, Daniela; Silva, Artur M S; Fernandes, Eduarda

    2017-03-11

    In response to an inflammatory stimulus, arachidonic acid (AA), the main polyunsaturated fatty acid present in the phospholipid layer of cell membranes, is released and metabolized to a series of eicosanoids. These bioactive lipid mediators of inflammation arise physiologically through the action of the enzymes 5-lipoxygenase (5-LOX) and cyclooxygenases (constitutive COX-1 and inducible COX-2). It is believed that dual inhibition of 5-LOX and COXs may have a higher beneficial impact in the treatment of inflammatory disorders rather than the inhibition of each enzyme. With this demand for new dual-acting anti-inflammatory agents, a range of 2,3-diarylxanthones were tested through their ability to interact in the AA metabolism. In vitro anti-inflammatory activity was evaluated through the inhibition of 5-LOX-catalyzed leukotriene B4 (LTB4) formation in human neutrophils and inhibition of COX-1- and COX-2-catalyzed prostaglandin E2 (PGE2) formation in human whole blood. The results showed that some of the studied arylxanthones were able to prevent LTB4 production in human neutrophils, in a concentration-dependent manner. The xanthone with a 2-catechol was the most active one (IC50 ∼ 9 μM). The more effective arylxanthones in preventing COX-1-catalyzed PGE2 production presented IC50 values from 1 to 7 μM, exhibiting a structural feature with at least one non-substituted aryl group. All the studied arylxanthones were ineffective to prevent the formation of PGE2 catalyzed by COX-2, up to the maximum concentration of 100 μM. The ability of the tested 2,3-diarylxanthones to interact with both 5-LOX and COX-1 pathways constitutes an important step in the research of novel dual-acting anti-inflammatory drugs.

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

    Science.gov (United States)

    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.

  20. 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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. FATTY ACIDS PROFILE IN A HIGH CELL DENSITY CULTURE OF ARACHIDONIC ACID-RICH PARIETOCHLORIS INCISA (TREBOUXIOPHYCEAE,CHLOROPHYTA) EXPOSED TO HIGH PFD

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The changes in arachidonic acid (AA) and fatty acids profiles along the growth curve of Parietochloris incisa, a coccoid snow green alga, were studied in a 2.8 cm light-path flat photobioreactor, exposed to strong photon flux density [PFD, 2400 μEmol/(m2*s)]. Sixteen fatty acids were identified by gas chromatography showing that AA was the dominant fatty acid (33%-41%) followedby linoleic acid (17%-21%). AA content was closely investigated with respect tototal fatty acids (TFA), ash free dry weight (AFDW) of cell mass as well as total culture content. These parameters were influenced significantly in a similar manner by culture growth phase, i.e., slightly decreasing in the lag period, gradually increasing in the logarithmic phase, becoming maximal at the early stationary phase, starting to decrease at the late stationary phase, sharply dropping at the decline phase. The increase in AA per culture volume during the logarithmic phase was not only associated with the increase in AFDW but also connected with a corresponding increase in AA/TFA, TFA/AFDW as well as AA/AFDW. The sharp decrease in AA content of the culture during the decline phase was mainly due to the decrease in AA/TFA, TFA/AFDW and AA/AFDW, although AFDW declined only a smallextent. Maximal AA concentration, obtained at the early stationary phase, was 900 mg/L culture volume, and the average daily net increase of AA during 9 days logarithmic growth was 1.7 g/(m2*day). Therefore, harvesting prior to the declinephase in a batch culture, or at steady state in continuous culture mode seems best for high AA production. The latter possibility was also further confirmed bycontinuous culture with 5 gradients of harvesting rate. ``

  2. Extract of a spice--omum (Trachyspermum ammi)-shows antiaggregatory effects and alters arachidonic acid metabolism in human platelets.

    Science.gov (United States)

    Srivastava, K C

    1988-07-01

    An ethereal extract of omum (Trachyspermum ammi; Hindustani: ajwan)--a frequently consumed spice--was found to inhibit platelet aggregation induced by arachidonic acid (AA), epinephrine and collagen; in this respect it was most effective against AA-induced aggregation. Inhibition of aggregation by omum could be explained by its effect on platelet thromboxane production as suggested by the following experimental observation. (i) Omum reduced TxB2 formation in intact platelet preparations from added arachidonate, and (ii) it reduced the formation of TxB2 from AA-labelled platelets after stimulation with Ca2+-ionophore A23187 by a direct action on cyclooxygenase as it did not affect the release of AA from labelled platelets. An increased formation of lipoxygenase-derived products from exogenous AA in omum-treated platelets was apparently due to redirection of AA from cyclooxygenase to the lipoxygenase pathway.

  3. Effects of dynamic exercise on plasma arachidonic acid epoxides and diols in human volunteers.

    Science.gov (United States)

    Giordano, Rose M; Newman, John W; Pedersen, Theresa L; Ramos, Marisa I; Stebbins, Charles L

    2011-12-01

    Metabolites of the cytochrome P450 (CYP) pathway may contribute to vasodilation of the vasculature. However, it is not known whether exercise affects their circulating concentrations. The authors determined effects of exercise intensity and duration on plasma concentrations of epoxy and dihydroxy metabolites of arachidonic acid. Their goal was to delineate the threshold workload, optimal workload, and duration required to produce increases in plasma concentrations of these vasoactive substances. Healthy volunteers (N = 14) performed maximal exercise testing on a bicycle ergometer during Visit 1. On separate days, subjects cycled for 20 min at 30%, 60%, and 80% of their maximal exercise intensity. The last day consisted of 40 min of exercise at 60% of maximal exercise intensity. Venous blood was obtained before, during, and after exercise for analysis. Compared with rest, increases were observed during the 80% workload at 20 min postexercise -14,15-DHET (0.77 ± 0.21 vs. 0.93 ± 0.27 nM) - and at 2 min postexercise: 11,12-DHET (0.64 ± 0.22 vs. 0.71 ± 0.24 nM; p < .05). Also compared with rest, 40-min values during the 60% workload were 14,15-DHET 0.79 ± 0.22 vs. 0.91 ± 0.31 nM and at 2 min post 14,15 EET 0.12 ± 0.06 vs. 0.21 ± 0.16 nM (p < .05). Results suggest the CYP metabolites (i.e., DHETs) are released during short-term high-intensity and long-term moderate-intensity exercise.

  4. Year-round high arachidonic acid levels in herbivorous rabbit fish Siganus fuscescens tissues.

    Science.gov (United States)

    Osako, Kazufumi; Saito, Hiroaki; Kuwahara, Koichi; Okamoto, Akira

    2006-05-01

    To identify a stable resource of 20:4 n-6 (arachidonic acid, AA) in marine fish tissues, the lipid profiles of Siganus fuscescens organs (muscle, liver, and other viscera) and stomach contents were examined throughout the year. Crude total lipid (TL) contents in respective organs showed seasonal variations and were high in winter and low in summer. The main FA in TL were 16:0, 18:0, 16:1n-7, 18:1n-9, AA, and 22:6n-3 (DHA). These FA were those generally observed in marine fish lipids, except for comparatively high levels of AA. In TL of muscle and liver, AA showed relatively high values during the period from late May to August (muscle, 4.6-13.1%; liver, 4.5-9.1%), compared with other seasons (muscle, 4.3-9.5%; liver, 3.6-8.4%). The AA levels in TL of other viscera and stomach contents fluctuated (other viscera, 2.0-10.7%; stomach contents, 7.6-26.7%). Regardless of the fishing season, each organ contained a higher level of AA in polar lipids (PL) than in neutral lipids. It was concluded that the fish contain comparatively high levels of AA in their TL throughout the year, and they accumulate AA characteristically in their tissue PL, probably from dietary food sources. Moreover, it was suggested that S. fuscescens has potential utility as a natural marine source of nutritional lipids, because the fish contain comparatively high levels of DHA and AA.

  5. Regulation of rat intrapulmonary arterial tone by arachidonic acid and prostaglandin E2 during hypoxia.

    Directory of Open Access Journals (Sweden)

    Gaoliang Yan

    Full Text Available AIMS: Arachidonic acid (AA and its metabolites, prostaglandins (PG are known to be involved in regulation of vascular homeostasis including vascular tone and vessel wall tension, but their potential role in Hypoxic pulmonary vasoconstriction (HPV remains unclear. In this study, we examined the effects of AA and PGE2 on the hypoxic response in isolated rat intrapulmonary arteries (IPAs. METHODS AND RESULTS: We carried out the investigation on IPAs by vessel tension measurement. Isotetrandrine (20 µM significantly inhibited phase I, phase IIb and phase IIc of hypoxic vasoconstriction. Both indomethacin (100 µM and NS398 attenuated KPSS-induced vessel contraction and phase I, phase IIb and phase IIc of HPV, implying that COX-2 plays a primary role in the hypoxic response of rat IPAs. PGE2 alone caused a significant vasoconstriction in isolated rat IPAs. This constriction is mediated by EP4. Blockage of EP4 by L-161982 (1 µM significantly inhibited phase I, phase IIb and phase IIc of hypoxic vasoconstriction. However, AH6809 (3 µM, an antagonist of EP1, EP2, EP3 and DP1 receptors, exerted no effect on KPSS or hypoxia induced vessel contraction. Increase of cellular cAMP by forskolin could significantly reduce KPSS-induced vessel contraction and abolish phase I, phase II b and phase II c of HPV. CONCLUSION: Our results demonstrated a vasoconstrictive effect of PGE2 on rat IPAs and this effect is via activation of EP4. Furthermore, our results suggest that intracellular cAMP plays dual roles in regulation of vascular tone, depending on the spatial distribution of cAMP and its coupling with EP receptor and Ca(2+ channels.

  6. Immunopathogenesis of HIV infection in cocaine users: role of arachidonic acid.

    Science.gov (United States)

    Samikkannu, Thangavel; Rao, Kurapati V K; Ding, Hong; Agudelo, Marisela; Raymond, Andrea D; Yoo, Changwon; Nair, Madhavan P N

    2014-01-01

    Arachidonic acid (AA) is known to be increased in HIV infected patients and illicit drug users are linked with severity of viral replication, disease progression, and impaired immune functions. Studies have shown that cocaine accelerates HIV infection and disease progression mediated by immune cells. Dendritic cells (DC) are the first line of antigen presentation and defense against immune dysfunction. However, the role of cocaine use in HIV associated acceleration of AA secretion and its metabolites on immature dendritic cells (IDC) has not been elucidated yet. The aim of this study is to elucidate the mechanism of AA metabolites cyclooxygenase-2 (COX-2), prostaglandin E2 synthetase (PGE2), thromboxane A2 receptor (TBXA2R), cyclopentenone prostaglandins (CyPG), such as 15-deoxy-Δ12,14-PGJ2 (15d-PGJ2), 14-3-3 ζ/δ and 5-lipoxygenase (5-LOX) mediated induction of IDC immune dysfunctions in cocaine using HIV positive patients. The plasma levels of AA, PGE2, 15d-PGJ2, 14-3-3 ζ/δ and IDC intracellular COX-2 and 5-LOX expression were assessed in cocaine users, HIV positive patients, HIV positive cocaine users and normal subjects. Results showed that plasma concentration levels of AA, PGE2 and COX-2, TBXA2R and 5-LOX in IDCs of HIV positive cocaine users were significantly higher whereas 15d-PGJ2 and 14-3-3 ζ/δ were significantly reduced compared to either HIV positive subjects or cocaine users alone. This report demonstrates that AA metabolites are capable of mediating the accelerative effects of cocaine on HIV infection and disease progression.

  7. Immunopathogenesis of HIV infection in cocaine users: role of arachidonic acid.

    Directory of Open Access Journals (Sweden)

    Thangavel Samikkannu

    Full Text Available Arachidonic acid (AA is known to be increased in HIV infected patients and illicit drug users are linked with severity of viral replication, disease progression, and impaired immune functions. Studies have shown that cocaine accelerates HIV infection and disease progression mediated by immune cells. Dendritic cells (DC are the first line of antigen presentation and defense against immune dysfunction. However, the role of cocaine use in HIV associated acceleration of AA secretion and its metabolites on immature dendritic cells (IDC has not been elucidated yet. The aim of this study is to elucidate the mechanism of AA metabolites cyclooxygenase-2 (COX-2, prostaglandin E2 synthetase (PGE2, thromboxane A2 receptor (TBXA2R, cyclopentenone prostaglandins (CyPG, such as 15-deoxy-Δ12,14-PGJ2 (15d-PGJ2, 14-3-3 ζ/δ and 5-lipoxygenase (5-LOX mediated induction of IDC immune dysfunctions in cocaine using HIV positive patients. The plasma levels of AA, PGE2, 15d-PGJ2, 14-3-3 ζ/δ and IDC intracellular COX-2 and 5-LOX expression were assessed in cocaine users, HIV positive patients, HIV positive cocaine users and normal subjects. Results showed that plasma concentration levels of AA, PGE2 and COX-2, TBXA2R and 5-LOX in IDCs of HIV positive cocaine users were significantly higher whereas 15d-PGJ2 and 14-3-3 ζ/δ were significantly reduced compared to either HIV positive subjects or cocaine users alone. This report demonstrates that AA metabolites are capable of mediating the accelerative effects of cocaine on HIV infection and disease progression.

  8. The 5-lipoxygenase inhibitor, zileuton, suppresses prostaglandin biosynthesis by inhibition of arachidonic acid release in macrophages

    Science.gov (United States)

    Rossi, A; Pergola, C; Koeberle, A; Hoffmann, M; Dehm, F; Bramanti, P; Cuzzocrea, S; Werz, O; Sautebin, L

    2010-01-01

    BACKGROUND AND PURPOSE Zileuton is the only 5-lipoxygenase (5-LOX) inhibitor marketed as a treatment for asthma, and is often utilized as a selective tool to evaluate the role of 5-LOX and leukotrienes. The aim of this study was to investigate the effect of zileuton on prostaglandin (PG) production in vitro and in vivo. EXPERIMENTAL APPROACH Peritoneal macrophages activated with lipopolysaccharide (LPS)/interferon γ (LPS/IFNγ), J774 macrophages and human whole blood stimulated with LPS were used as in vitro models and rat carrageenan-induced pleurisy as an in vivo model. KEY RESULTS Zileuton suppressed PG biosynthesis by interference with arachidonic acid (AA) release in macrophages. We found that zileuton significantly reduced PGE2 and 6-keto prostaglandin F1α (PGF1α) levels in activated mouse peritoneal macrophages and in J774 macrophages. This effect was not related to 5-LOX inhibition, because it was also observed in macrophages from 5-LOX knockout mice. Notably, zileuton inhibited PGE2 production in LPS-stimulated human whole blood and suppressed PGE2 and 6-keto PGF1α pleural levels in rat carrageenan-induced pleurisy. Interestingly, zileuton failed to inhibit the activity of microsomal PGE2 synthase1 and of cyclooxygenase (COX)-2 and did not affect COX-2 expression. However, zileuton significantly decreased AA release in macrophages accompanied by inhibition of phospholipase A2 translocation to cellular membranes. CONCLUSIONS AND IMPLICATION Zileuton inhibited PG production by interfering at the level of AA release. Its mechanism of action, as well as its use as a pharmacological tool, in experimental models of inflammation should be reassessed. PMID:20880396

  9. Effect of in vivo coal dust exposure on arachidonic acid metabolism in the rat alveolar macrophage

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, D.C.; Stanley, C.F.; El-Ayouby, N.; Demers, L.M. (Pennsylvania State Univ., Hershey, PA (USA). M.S. Hershey Medical Center, Dept. of Pathology)

    1990-01-01

    Oxygenated metabolites of arachidonic acid (AA) are produced by the alveolar macrophage (AM) and have been shown to mediate inflammatory reactions. We therefore assessed the production of eicosanoids by AM harvested from the lungs of rats exposed to a bituminous coal dust for 2 wk in an inhalation chamber in order to determine if AA metabolism was altered in a manner that may promote an inflammatory response in the lung. Exposure to coal dust resulted in a 66% increase in the number of AM harvested, an increase in thromboxane A{sub 2}(TxA{sub 2}) and leukotriene B{sub 4} (LTB{sub 4}) production to 222% and 181% of control values, respectively, and a decrease in prostaglandin E{sub 2} (PGE{sub 2}) production to 62% of control values. In AM harvested from rats allowed to breathe clean air for 2 wk following coal dust exposure, PGE{sub 2} production returned to control levels but TxA{sub 2} and LTB{sub 4} production remained elevated. The TxA{sub 2} synthesis inhibitor UK 38,485 reduced TxA{sub 2} production in dust-exposed AM both immediately and 2 wk following exposure. Thus, exposure of rats to coal dust significantly alters the metabolism of AA in AM, with potentially important aspects of AA metabolism remaining altered even after a 2-wk recovery period. Based on the established role of eicosanoids in inflammatory and fibrotic processes, these results suggest that the alteration of AM eicosanoid production as a result of the inhalation of coal mine dust may be an important factor in the pathophysiology of coal workers' pneumoconiosis. 26 refs., 4 figs.

  10. [Action of adaptogens: cucurbitacin R diglucoside as a stimulator of arachidonic acid metabolism in the rat adrenal gland].

    Science.gov (United States)

    Panosian, A G; Dadaian, M A; Gevorkian, G A

    1989-01-01

    It has been demonstrated that cucurbitacin R diglucoside (CRD), an adaptogen increasing the rat working capacity and stimulating corticosteroid secretion, stimulates the release of arachidonic acid (AA) in the rat adrenal cortex in vivo (the administration of CRD during 14 days) as well as in vitro (the incubation of isolated rat adrenocortical cells with CRD in the presence of eicosatetraenoic acid, the AA metabolism inhibitor) experiments. The incubation of isolated rat adrenocortical cell with CRD in the presence of AA increases the biosynthesis of 5-HETE, the precursor of which 5-HPETE is known to be a modulator of ACTH-induced corticosteroid secretion.

  11. Allometric scaling of dietary linoleic acid on changes in tissue arachidonic acid using human equivalent diets in mice

    Directory of Open Access Journals (Sweden)

    Whelan Jay

    2011-06-01

    Full Text Available Abstract Background It is hypothesized that dietary linoleic acid (LA promotes chronic and acute diseases in humans by enriching tissues with arachidonic acid (AA, its downstream metabolite, and dietary studies with rodents have been useful for validation. However, levels of LA in research diets of rodents, as published in the literature, are notoriously erratic making interspecies comparisons unreliable. Therefore, the ability to extrapolate the biological effects of dietary LA from experimental rodents to humans necessitates an allometric scaling model that is rooted within a human equivalent context. Methods To determine the physiological response of dietary LA on tissue AA, a mathematical model for extrapolating nutrients based on energy was used, as opposed to differences in body weight. C57BL/6J mice were divided into 9 groups fed a background diet equivalent to that of the US diet (% energy with supplemental doses of LA or AA. Changes in the phospholipid fatty acid compositions were monitored in plasma and erythrocytes and compared to data from humans supplemented with equivalent doses of LA or AA. Results Increasing dietary LA had little effect on tissue AA, while supplementing diets with AA significantly increased tissue AA levels, importantly recapitulating results from human trials. Conclusions Thus, interspecies comparisons for dietary LA between rodents and humans can be achieved when rodents are provided human equivalent doses based on differences in metabolic activity as defined by energy consumption.

  12. Effects of Long-Term Oral Administration of Arachidonic Acid and Docosahexaenoic Acid on the Immune Functions of Young Rats

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    Osamu Shido

    2013-05-01

    Full Text Available Natural killer (NK cells have many functional activities, including cytotoxicity and the capacity to produce cytokines and chemokines. NK cell activity is regulated partly by eicosanoids, which are produced from arachidonic acid (ARA and eicosapentaenoic (EPA acid. In this study, we investigated the effects of long-term therapy with ARA or docosahexaenoic acid (DHA on the cytotoxic effects of the NK cells of young rats, which were fed on a nonfish oil diet for two generations. Control oil, ARA (240 mg/kg BW/day or DHA (240 mg/kg BW/day were orally administrated to the rats for 13 weeks before determining the cytotoxic activity of NK cells from the spleen against YAC-1 mouse lymphoma cell line, as well as the plasma levels of docosanoids or eicosanoids and inflammatory cytokines. Long-term ARA administration significantly suppressed the cytotoxic activity of NK cells. Moreover, ARA administration significantly increased the plasma levels of ARA, prostaglandin (PG E2, and PGD2. However, DHA administration did not produce any different effects compared with those in the control rats. Furthermore, the inflammatory cytokine levels were not affected by the administration of ARA or DHA. These results suggest that long-term ARA administration has an inhibitory effect on the tumor cytotoxicity of NK cells in rat spleen lymphocytes owing to the enhanced synthesis of PGE2 and PGD2 from ARA because of the elevated plasma ARA levels in young rats.

  13. Pathways of arachidonic acid peroxyl radical reactions and product formation with guanine radicals.

    Science.gov (United States)

    Crean, Conor; Geacintov, Nicholas E; Shafirovich, Vladimir

    2008-02-01

    Peroxyl radicals were derived from the one-electron oxidation of polyunsaturated fatty acids by sulfate radicals that were generated by the photodissociation of peroxodisulfate anions in air-equilibrated aqueous solutions. Reactions of these peroxyl and neutral guanine radicals, also generated by oxidation with sulfate radicals, were investigated by laser kinetic spectroscopy, and the guanine oxidation products were identified by HPLC and mass spectrometry methods. Sulfate radicals rapidly oxidize arachidonic (ArAc), linoleic (LnAc), and palmitoleic (PmAc) acids with similar rate constants, (2-4) x 10 (9) M (-1) s (-1). The C-centered radicals derived from the oxidation of ArAc and LnAc include nonconjugated Rn(.) ( approximately 80%) and conjugated bis-allylic Rba(.) ( approximately 20%) radicals. The latter were detectable in the absence of oxygen by their prominent, narrow absorption band at 280 nm. The Rn(.) radicals of ArAc (containing three bis-allylic sites) transform to the Rba(.) radicals via an intramolecular H-atom abstraction [rate constant (7.5 +/- 0.7) x 10 (4) s (-1)]. In contrast, the Rn(.) radicals of LnAc that contain only one bis-allylic site do not transform intramolecularly to the Rba(.) radicals. In the case of PmAc, which contains only one double bond, the Rba(.) radicals are not observed. The Rn(.) radicals of PmAc rapidly combine with oxygen with a rate constant of (3.8 +/- 0.4) x 10(9) M(-1) s(-1). The Rba(.) radicals of ArAc are less reactive and react with oxygen with a rate constant of (2.2 +/- 0.2) x 10 (8) M (-1) s (-1). The ArAc peroxyl radicals formed spontaneously eliminate superoxide radical anions [rate constant = (3.4 +/- 0.3) x 10 (4) M (-1) s (-1)]. The stable oxidative lesions derived from the 2',3',5'-tri- O-acetylguanosine or 2',3',5'-tri- O-acetyl-8-oxo-7,8-dihydroguanosine radicals and their subsequent reactions with ArAc peroxyl radicals were also investigated. The major products found were the 2,5-diamino-4 H

  14. In vitro ozone exposure increases release of arachidonic acid products from a human bronchial epithelial cell line

    Energy Technology Data Exchange (ETDEWEB)

    McKinnon, K.P.; Madden, M.C.; Noah, T.L.; Devlin, R.B. (TRC Environmental Corporation, Chapel Hill, NC (United States))

    1993-02-01

    Eicosanoids released after ozone exposure of a human bronchial epithelial cell line, BEAS-S6, were analyzed by high-pressure liquid chromatography (HPLC) of supernatants from exposed cells prelabeled with [3H]arachidonic acid. BEAS cells released thromboxane B2 (TxB2), prostaglandin E2 (PGE2), leukotriene C4 (LTC4), LTD4, LTE4, and 12-hydroxyheptadecatrienoic acid (HHT) after exposure to ozone at concentrations of 0.1, 0.25, 0.5, and 1.0 ppm. The eicosanoids were identified by coelution with authentic standards. The largest product from ozone-exposed BEAS cells was the most polar peak, designated Peak 1. Release of cyclooxygenase products such as TxB2, PGE2, and HHT was inhibited by acetylsalicylic acid. Peaks that migrated with authentic standards for LTB4, LTC4, and LTD4 were inhibited by the lipoxygenase inhibitor nordihydroguaiaretic acid. The leukotrienes LTB4 and LTC4/D4 could also be detected by immunoassay of concentrated peak fractions. Thus BEAS cells released eicosanoids from cyclooxygenase and lipoxygenase pathways of arachidonic acid metabolism following exposure to ozone. Airway epithelial cells may be an important source of eicosanoids following ozone stimulation in humans.

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

    Science.gov (United States)

    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.

  16. Arachidonic Acid and Cerebral Ischemia Risk: A Systematic Review of Observational Studies

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    Mai Sakai

    2014-11-01

    Full Text Available Background: Arachidonic acid (ARA is a precursor of various lipid mediators. ARA metabolites such as thromboxane A2 cause platelet aggregation and vasoconstriction, thus may lead to atherosclerotic disease. It is unclear whether dietary ARA influences the ARA-derived lipid mediator balance and the risk for atherosclerotic diseases, such as cerebral ischemia. Considering the function of ARA in atherosclerosis, it is reasonable to focus on the atherothrombotic type of cerebral ischemia risk. However, no systematic reviews or meta-analyses have been conducted to evaluate the effect of habitual ARA exposure on cerebral ischemia risk. We aimed to systematically evaluate observational studies available on the relationship between ARA exposure and the atherothrombotic type of cerebral ischemia risk in free-living populations. Summary: The PubMed database was searched for articles registered up to June 24, 2014. We designed a PubMed search formula as follows: key words for humans AND brain ischemia AND study designs AND ARA exposure. Thirty-three articles were reviewed against predefined criteria. There were 695 bibliographies assessed from the articles that included both ARA and cerebral ischemia descriptions. Finally, we identified 11 eligible articles and categorized them according to their reporting and methodological quality. We used the Strengthening the Reporting of Observational Studies in Epidemiology Statement (STROBE checklist to score the reporting quality. The methodological quality was qualitatively assessed based on the following aspects: subject selection, ARA exposure assessment, outcome diagnosis, methods for controlling confounders, and statistical analysis. We did not conduct a meta-analysis due to the heterogeneity among the studies. All eligible studies measured blood ARA levels as an indicator of exposure. Our literature search did not identify any articles that evaluated dietary ARA intake and tissue ARA as assessments of

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

    Directory of Open Access Journals (Sweden)

    Weiss Carsten

    2011-08-01

    Full Text Available Abstract 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

  18. The role of arachidonic acid metabolism in virus-induced alveolar macrophage dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Laegreid, W.W.

    1988-01-01

    Alveolar macrophages (AM) recovered from virus-infected lungs have decreased phagocytic, respiratory burst and bactericidal activities. The studies described below investigated the role of eicosanoids in virus induced AM bactericidal dysfunction. The spectrum of eicosanoid metabolites which bovine AM are capable of producing was determined. Cultured AM were exposed to {sup 3}H-arachidonate for 1 hour, stimulated for 4 hours with A23187, phorbol myristate acetate or zymosan and the supernatants extracted and analyzed by HPLC. All stimuli tested caused the release of these cyclooxygenase metabolites: thromboxane B{sub 2}, PGF{sub 2}, PGE{sub 2}, PGD{sub 2} and HHT. The effect of this enhanced release of arachidonate metabolites on the ability of AM to kill bacteria was evaluated. Preincubation with cyclooxygenase inhibitors or dual cyclooxygenase and lipoxygenase inhibitors resulted in partial reversal of the virus-induced bactericidal deficit in PI3 infected AM.

  19. Dietary fatty acids and the stress response of fish : arachidonic acid in seabream and tilapia

    NARCIS (Netherlands)

    Anholt, Rogier Daniël van

    2004-01-01

    A key factor in the production of fish in commercial aquaculture is the optimization of the artificial diets, not only to achieve optimal growth, but also to maximize fish health. Evidence is accumulating that dietary lipids, particularly the fatty acid composition, can have a direct effect on the f

  20. Pregnancy duration and the ratio of long-chain n-3 fatty acids to arachidonic acid in erythrocytes from Faroese women

    DEFF Research Database (Denmark)

    Olsen, S.F.; Hansen, Harald S.; Jensen, B.

    1989-01-01

    Dietary long-chain n-3 fatty acids (FA) may prolong gestation by inhibiting formation of prostaglandins from arachidonic acid. FA were quantified in phosphatidylcholine (PC), phosphatidylethanolamine (PE), and total lipids (TL) of red cells sampled during pregnancy from 29 Faroese women. The ratio...... of long-chain n-3 FA to arachidonic acid (the (3/6) ratio) was used as the most relevant single measure of exposure. In 18 women with certain gestational age and with spontaneous onset of delivery, gestational age was significantly associated with the (3/6) ratio quantified in PC (correlation coefficient...... 0.50, P = 0.035), but not with the (3/6) radio in PE (correlation coefficient 0.21, P = 0.40) or TL (correlation coefficient 0.29, P = 0.26). The association with the (3/6) ratio in PC could not be attributed to confounding by maternal age, weight, marital status or smoking....

  1. Effect of extra virgin olive oil components on the arachidonic acid cascade, colorectal cancer and colon cancer cell proliferation

    Directory of Open Access Journals (Sweden)

    C. E. Storniolo

    2016-12-01

    Full Text Available The mediterranean diet (MD reduced the risk of colorectal cancer (CRC, and olive oil, the primary source of fat in the MD, has also been found to have a protective effect. However, animals fed with oleic acid present a high number of intestinal tumours, suggesting that oleic acid and olive oil consumption can exert different effects on CRC. Considering that extra virgin olive oil (EVOO is a complex mix of fatty acids and minor compounds such as polyphenols, hydrocarbons, phytosterols and triterpenes; and that these compounds have antioxidant activity and consequently they can modulate the arachidonic acid (AA cascade and eicosanoid synthesis. This review analyzes the state of the art of olive oil components on the AA cascade and cellular mechanism involved in CRC such as intestinal epithelial cell growth/apoptosis, to understand the fact that the consumption of seed oils with high oleic content or EVOO will probably have different effects on CRC development.

  2. Structure-activity relationship studies of 1-substituted 3-dodecanoylindole-2-carboxylic acids as inhibitors of cytosolic phospholipase A2-mediated arachidonic acid release in intact platelets.

    Science.gov (United States)

    Griessbach, Klaus; Klimt, Monika; Schulze Elfringhoff, Alwine; Lehr, Matthias

    2002-01-01

    A series of 3-dodecanoylindole-2-carboxylic acid derivatives with varied carboxylic acid substituents at the indole 1-position were synthesized and evaluated for their ability to inhibit arachidonic acid release in human platelets mediated by the cytosolic phospholipase A(2). Structure-activity relationship studies revealed that increasing the polarity of these substituents by the introduction of additional polar groups in the proximity of the carboxylic acid moiety reduced activity. Conformational restriction of the indole-1-carboxylic acid substituents in distinct positions as well as extending the length of these residues led to compounds which did not substantially differ in their potencies.

  3. Decreases in Phospholipids Containing Adrenic and Arachidonic Acids Occur in the Human Hippocampus over the Adult Lifespan.

    Science.gov (United States)

    Hancock, Sarah E; Friedrich, Michael G; Mitchell, Todd W; Truscott, Roger J W; Else, Paul L

    2015-09-01

    One of the biggest risk factors for developing Alzheimer's disease is advanced age. Despite several studies examining changes to phospholipids in the hippocampus during the pathogenesis of Alzheimer's disease, little is known regarding changes to phospholipids in this region during normal adult aging. This study examined the phospholipid composition of the mitochondrial and microsomal membranes of the human hippocampus from post-mortem tissue of neurologically normal subjects aged between 18 and 104 years. Many of the age-related changes found were in low-to-moderately abundant phospholipids in both membrane fractions, with decreases with age being seen in many phospholipids containing either adrenic or arachidonic acid. The most abundant phospholipid of this type was phosphatidylethanolamine 18:0_22:4, which decreased in both the mitochondrial and microsomal membranes by approximately 20% from ages 20 to 100. Subsequent decreases with age were seen in total adrenic and arachidonic acid in the phospholipids of both membrane fractions, but not in either fatty acid specifically within the phosphatidylethanolamine class. Increases with age were seen in the hippocampus for mitochondrial phosphatidylserine 18:0_22:6. This is the first report of changes to molecular phospholipids of the human hippocampus over the adult lifespan, with this study also providing a comprehensive profile of the phosphatidylcholine, phosphatidylethanolamine and phosphatidylserine phospholipids of the human hippocampus.

  4. An Optimized High Throughput Clean-Up Method Using Mixed-Mode SPE Plate for the Analysis of Free Arachidonic Acid in Plasma by LC-MS/MS

    OpenAIRE

    Wan Wang; Suzi Qin; Linsen Li; Xiaohua Chen; Qunjie Wang; Junfu Wei

    2015-01-01

    A high throughput sample preparation method was developed utilizing mixed-mode solid phase extraction (SPE) in 96-well plate format for the determination of free arachidonic acid in plasma by LC-MS/MS. Plasma was mixed with 3% aqueous ammonia and loaded into each well of 96-well plate. After washing with water and methanol sequentially, 3% of formic acid in acetonitrile was used to elute arachidonic acid. The collected fraction was injected onto a reversed phase column at 30°C with mobile pha...

  5. Impact of arachidonic acid enrichment of live rotifer prey on bacterial communities in rotifer and larval fish cultures.

    Science.gov (United States)

    Seychelles, Laurent H; Doiron, Kim; Audet, Céline; Tremblay, Réjean; Pernet, Fabrice; Lemarchand, Karine

    2013-03-01

    Rotifers (Brachionus plicatilis), commonly used at first feeding in commercial fish hatcheries, carry a large bacteria load. Because they are relatively poor in essential fatty acids, it is common practice to enrich them with fatty acids, including arachidonic acid (AA). This study aims to determine whether prey enrichment with AA may act as a prebiotic and modify the microbial community composition either in AA-enriched rotifer cultures or in larval-rearing water using winter flounder (Pseudopleuronectes americanus) as a larval fish model. AA enrichment modified the bacterial community composition in both the rotifer culture tanks and the larval-rearing tanks. We observed an increase in the number of cultivable bacteria on TCBS (thiosulfate-citrate-bile salts-sucrose) agar, used as a proxy for the abundance of Vibrio sp. The results suggest that AA may also play an indirect role in larval health.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Combining eicosapentaenoic acid, decosahexaenoic acid and arachidonic acid, using a fully crossed design, affect gene expression and eicosanoid secretion in salmon head kidney cells in vitro.

    Science.gov (United States)

    Holen, Elisabeth; He, Juyun; Espe, Marit; Chen, Liqiou; Araujo, Pedro

    2015-08-01

    Future feed for farmed fish are based on untraditional feed ingredients, which will change nutrient profiles compared to traditional feed based on marine ingredients. To understand the impact of oils from different sources on fish health, n-6 and n-3 polyunsaturated fatty acids (PUFAs) were added to salmon head kidney cells, in a fully crossed design, to monitor their individual and combined effects on gene expression. Exposing salmon head kidney cells to single fatty acids, arachidonic acid (AA) or decosahexaenoic acid (DHA), resulted in down-regulation of cell signaling pathway genes and specific fatty acid metabolism genes as well as reduced prostaglandin E2 (PGE2) secretion. Eicosapentaenoic acid (EPA) had no impact on gene transcription in this study, but reduced the cell secretion of PGE2. The combined effect of AA + EPA resulted in up-regulation of eicosanoid pathway genes and the pro-inflammatory cytokine, tumor necrosis factor alpha (TNF-α), Bclx (an inducer of apoptosis) and fatty acid translocase (CD36) as well as increased cell secretion of PGE2 into the media. Adding single fatty acids to salmon head kidney cells decreased inflammation markers in this model. The combination AA + EPA acted differently than the rest of the fatty acid combinations by increasing the inflammation markers in these cells. The concentration of fatty acid used in this experiment did not induce any lipid peroxidation responses.

  8. Decreased arachidonic acid content and metabolism in tissues of NZB/W F1 females fed a diet containing 0. 45% dehydroisoandrosterone (DHA)

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

  10. Targeting arachidonic acid pathway to prevent programmed hypertension in maternal fructose-fed male adult rat offspring.

    Science.gov (United States)

    Tain, You-Lin; Lee, Wei-Chia; Wu, Kay L H; Leu, Steve; Chan, Julie Y H

    2016-12-01

    Hypertension can be programmed in response to nutritional insults in early life. Maternal high-fructose (HF) intake induced programmed hypertension in adult male offspring, which is associated with renal programming and arachidonic acid metabolism pathway. We examined whether early treatment with a soluble epoxide hydrolase (SEH) inhibitor, 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA) or 15-Deoxy-Δ(12,14)-prostagandin J2 (15dPGJ2) can prevent HF-induced programmed hypertension. Pregnant Sprague Dawley rats received regular chow or chow supplemented with fructose (60% diet by weight) during the whole period of pregnancy and lactation. Four groups of male offspring were studied: control, HF, HF+AUDA and HF+15dPGJ2. In HF+AUDA group, mother rats received AUDA 25 mg/L in drinking water during lactation. In the HF+15dPGJ2 group, male offspring received 15dPGJ2 1.5 mg/kg body weight by subcutaneous injection once daily for 1 week after birth. Rats were sacrificed at 12 weeks of age. Maternal HF-induced programmed hypertension is associated with increased renal protein level of SEH and oxidative stress, which early AUDA therapy prevents. Comparison of AUDA and 15dPGJ2 treatments demonstrated that AUDA was more effective in preventing HF-induced programmed hypertension. AUDA therapy increases angiotensin converting enzyme-2 (ACE2) protein levels and PGE2 levels in adult offspring kidney exposed to maternal HF. 15dPGJ2 therapy increases plasma asymmetric dimethylarginine (ADMA) levels and decreases L-arginine-to-ADMA ratio. Better understanding of the impact of arachidonic acid pathway, especially inhibition of SEH, on renal programming may aid in developing reprogramming strategy to prevent programmed hypertension in children exposed to antenatal HF intake.

  11. Biochemical and pharmacological effects of dipyrone and its metabolites in model systems related to arachidonic acid cascade.

    Science.gov (United States)

    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)

  12. Generation of trans-arachidonic acid under nitrative stress is associated with upregulation of thromponsdin-1 in diabetic rats

    Institute of Scientific and Technical Information of China (English)

    XU Lin; XU Xun; LIU Yu-min; YAO Zhu-jun; XUN Guo-liang; YU Wen-juan; LIU Kun; SUN Xiao-dong; QIU Yun-ping; WU Hai-xiang

    2011-01-01

    Background Trans-arachidonic acids (TAAs), newly discovered markers of nitrative stress and the major products of nitrogen dioxide (NO2)-mediated isomerization of arachidonic acid (AA), represent a new mechanism of NO2-induced toxicity. It has been reported that TAAs were generated in oxygen-induced microvascular degeneration model and TAAs were also generated in a diabetic retinopathy (DR) model. In this study, we examined high glucose-induced nitrative stress damage and TAAs levels and explored the possible mechanisms for DR caused by reactive nitrogen species. Methods Diabetic rats were induced by intraperitoneal injection of streptozotocin (STZ) at 60 mg/kg. Bovine retinal capillary endothelial cells (BRECs) were selectively cultured and incubated with normal or high glucose. The serum TAAs and AA in diabetic rats were measured by the gas chromatography and mass spectrometry (GC/MS) method. The ratio of peak area of TAAs to AA with selected ion of 79 was estimated by a group (-test. Thrombospondin-1 (TSP-1) in the rat retinas and BRECs extracts were examined by Western blotting. The phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) protein was examined by Western blotting in BRECs incubated with high glucose.Results The TAAs to AA ratio (TAAs/AA) was significantly increased in the serum at 8, 12 and 16 weeks after STZ injection (P 0.05). Expression of TSP-1 in the retina of diabetic rats was progressively elevated according to the duration of diabetes. TSP-1 expression was increased in BRECs incubated with high glucose at 48 hours. Moreover, high glucose also increased ERK1/2 expression, which peaked at 30 minutes and then decreased in the following 48 hours.Conclusion An elevation of TAAs/AA is associated with high glucose-induced nitrative stress, which probably involves upregulation of TSP-1 through activating ERK1/2.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. Potential antifungal targets against a Candida biofilm based on an enzyme in the arachidonic acid cascade - a review

    Directory of Open Access Journals (Sweden)

    Xinning Liu

    2016-12-01

    Full Text Available Candida is an important opportunistic fungal pathogen, especially in biofilm associated infections. The formation of a Candida biofilm can decrease Candida sensitivity to antifungal drugs and cause drug resistance. Although many effective antifungal drugs are available, their applications are limited due to their high toxicity and cost. Seeking new antifungal agents that are effective against biofilm-associated infection is an urgent need. Many research efforts are underway, and some progress has been made in this field. It has been shown that the arachidonic acid cascade plays an important role in fungal morphogenesis and pathogenicity. Notably, prostaglandin E2 (PGE2 can promote the formation of a Candida biofilm. Recently, the inhibition of PGE2 has received much attention. Studies have shown that cyclooxygenase (COX inhibitors, such as aspirin, ibuprofen and indomethacin, combined with fluconazole can significantly reduce Candida adhesion and biofilm development and increase fluconazole susceptibility; the MIC of fluconazole can be decrease from 64 to 2 μg/ml when used in combination with ibuprofen. In addition, in vivo studies have also confirmed the antifungal activities of these inhibitors. In this article, we mainly review the relationship between PGE2 and Candida biofilm, summarize the antifungal activities of COX inhibitors and analyze the possible antifungal activity of microsomal prostaglandin E synthase-1 (MPGES-1 inhibitors; additionally, other factors that influence PGE2 production are also discussed. Hopefully this review can disclose potential antifungal targets based on the arachidonic acid cascade and provide a prevailing strategy to alleviate C. albicans biofilm formation.

  15. Synergism between thapsigargin and the phorbol ester 12-O-tetradecanoylphorbol 13-acetate on the release of [C]arachidonic acid and histamine from rat peritoneal mast cells

    DEFF Research Database (Denmark)

    Jacobsen, S.; Hansen, Harald S.; Jensen, B.

    1987-01-01

    Thapsigargin is a potent skin irritating sesquiterpene lactone isolated from the roots of Thapsia garganica L. (Apiaceae). In rat peritoneal mast cells thapsigargin induced a calcium-dependent non-cytotoxic [C]arachidonic acid and histamine release. A minor amount of the released [C...

  16. The relation between the omega-3 index and arachidonic acid is bell shaped : Synergistic at low EPA plus DHA status and antagonistic at high EPA plus DHA status

    NARCIS (Netherlands)

    Luxwolda, Martine F.; Kuipers, Remko S.; Smit, Ella N.; Velzing-Aarts, Francien V.; Dijck-Brouwer, D. A. Janneke; Muskiet, Frits A. J.

    2011-01-01

    Introduction: The relation between docosahexaenoic (DHA) and eicosapentaenoic (EPA) vs. arachidonic acid (AA) seems characterized by both synergism and antagonism. Materials and methods: Investigate the relation between EPA + DHA and AA in populations with a wide range of EPA + DHA status and across

  17. Evaluation of a subchronic (13-week) oral toxicity study, preceded by an in utero exposure phase, with arachidonic acid oil derived from Mortierella alpina in rats

    NARCIS (Netherlands)

    Hempenius, R.A.; Lina, B.A.R.; Haggitt, R.C.

    2000-01-01

    Arachidonic acid oil (ARA-oil) derived from the fungus Mortierella alpina for use in infant nutrition was tested in a subchronic (13-week) oral toxicity study in rats, preceded by an in utero exposure phase. The ARA-oil was administered as admixture to the rodent diet at dose levels of 3000 ppm, 15,

  18. Evaluation of a subchronic (13-week) oral toxicity study, preceded by an in utero exposure phase, with arachidonic acid oil derived from Mortierella alpina in rats

    NARCIS (Netherlands)

    Hempenius, R.A.; Lina, B.A.R.; Haggitt, R.C.

    2000-01-01

    Arachidonic acid oil (ARA-oil) derived from the fungus Mortierella alpina for use in infant nutrition was tested in a subchronic (13-week) oral toxicity study in rats, preceded by an in utero exposure phase. The ARA-oil was administered as admixture to the rodent diet at dose levels of 3000 ppm,

  19. Evaluation of a subchronic (13-week) oral toxicity study, preceded by an in utero exposure phase, with arachidonic acid oil derived from Mortierella alpina in rats

    NARCIS (Netherlands)

    Hempenius, R.A.; Lina, B.A.R.; Haggitt, R.C.

    2000-01-01

    Arachidonic acid oil (ARA-oil) derived from the fungus Mortierella alpina for use in infant nutrition was tested in a subchronic (13-week) oral toxicity study in rats, preceded by an in utero exposure phase. The ARA-oil was administered as admixture to the rodent diet at dose levels of 3000 ppm, 15,

  20. High contents of both docosahexaenoic and arachidonic acids in milk of women consuming fish from lake Kitangiri (Tanzania) : targets for infant formulae close to our ancient diet?

    NARCIS (Netherlands)

    Kuipers, RS; Fokkema, MR; Smit, EN; van der Meulen, J; Boersma, ER; Muskiet, FAJ

    2005-01-01

    Current recommendations for arachidonic (AA) and docosahexaenoic (DHA) acids in infant formulae are based on milk of Western mothers. Validity may be questioned in view of the profound dietary changes in the past 100 years, as opposed to our slowly adapting genome. Hominin evolution occurred in the

  1. Consumption of pomegranate juice decreases blood lipid peroxidation and levels of arachidonic acid in women with metabolic syndrome.

    Science.gov (United States)

    Kojadinovic, Milica I; Arsic, Aleksandra C; Debeljak-Martacic, Jasmina D; Konic-Ristic, Aleksandra I; Kardum, Nevena Dj; Popovic, Tamara B; Glibetic, Marija D

    2017-04-01

    Pomegranate juice is a rich source of polyphenols and is thus a promising dietary antioxidant with numerous health-promoting effects. These include a beneficial impact on cardiovascular health that could be partly attributed to the effects of polyphenols on lipid metabolism. The aim of this study was to investigate whether consumption of pomegranate juice for 6 weeks could modify lipid peroxidation and phospholipid fatty acid composition of plasma and erythrocytes in subjects with metabolic syndrome. Twenty-three women, aged 40-60 years, were enrolled and randomly assigned into two groups: the intervention group, in which each participant consumed 300 mL of juice per day for 6 weeks; and a control group. A statistically significant decrease in the relative amount of arachidonic acid (P juice significantly increased the relative amount of total mono-unsaturated fatty acids (P juice on lipid peroxidation and fatty acid status in subjects with metabolic syndrome and suggest potential anti-inflammatory and cardio-protective effects. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  2. n-3 polyunsaturated fatty acids supplementation decreases asymmetric dimethyl arginine and arachidonate accumulation in aging spontaneously hypertensive rats.

    Science.gov (United States)

    Raimondi, Laura; Lodovici, Maura; Visioli, Francesco; Sartiani, Laura; Cioni, Laura; Alfarano, Chiara; Banchelli, Grazia; Pirisino, Renato; Cecchi, Enrica; Cerbai, Elisabetta; Mugelli, Alessandro

    2005-09-01

    Plasma accumulation of asymmetric dimethyl arginine (ADMA) is considered as a risk factor for endothelial dysfunction and a strong predictor for coronary heart diseases. Eicosapentaenoic (EPA) and docosahexaenoic (DHA) increasing plasma levels have been positively associated with reduced cardiovascular mortality with a mechanism( s) yet unclear. We hypothesised that ADMA reduction might be a part of EPA and DHA beneficial effects on the cardiovascular system. To verify this hypothesis we measured ADMA plasma levels in aged spontaneously hypertensive rats (SHR) supplemented for 8 weeks with EPA and DHA. 16-month-old SHR were supplemented with EPA and DHA (EPA-DHA) or with olive oil (1 g/kg/day; OLIVE). At the end of the treatments, the plasma of each animal was analysed for 1) the total fatty acid composition, by gas-cromatography, 2) ADMA levels, by high pressure liquid chromatography, 3) nitrite and homocysteine concentration by chemiluminescence and by polarisation immunoassay respectively. Moreover, the activity of dimethyl arginine dimethyl amino hydrolase, the main enzyme involved in ADMA metabolism, was measured spectrophotometrically in the kidney from each rat. Animals supplemented with EPA and DHA showed: 1) lower ADMA and arachidonate plasma levels (587.4 +/- 113.7 nM and 0.49 +/- 0.11 mM respectively) than the values found in OLIVE rats (1365 +/- 399 nM and 1.07 +/- 0.07 mM respectively) 2) higher nitrite content (0.73 +/- 0.05 microM) than OLIVE (0.23 +/- 0.08 microM). EPA and DHA supplementation reduced ADMA accumulation in SHR in parallel with a decrease of arachidonate availability. This finding suggests that the control of the inflammatory ground of endothelium might play an important role in EPA and DHA effect on this novel and highly predictive cardiovascular risk factor.

  3. Influence of -tocopherol on arachidonic acid deposition and peroxidation in Atlantic salmon (Salmo salar L.) fingerlings/Influencia del -tocoferol en la incorporacion y peroxidacion del acido araquidonico en alevines parr de salmon del Atlantico (Salmo salar L.)

    National Research Council Canada - National Science Library

    Dantagnan, Patricio; Dominguez, Astrid; Borquez, Aliro; Alcaino, Javier; Pavez, Claudio; Hernandez, Adrian

    2012-01-01

    The synergistic effect of arachidonic acid (ARA) (20:4n-6) and [alpha]-tocopherol on the accumulation of fatty acids and the peroxidation of lipids in liver and muscle was evaluated in Atlantic salmon (Salmo salar) juveniles...

  4. Cytochrome P450 CYP2J9, a new mouse arachidonic acid omega-1 hydroxylase predominantly expressed in brain.

    Science.gov (United States)

    Qu, W; Bradbury, J A; Tsao, C C; Maronpot, R; Harry, G J; Parker, C E; Davis, L S; Breyer, M D; Waalkes, M P; Falck, J R; Chen, J; Rosenberg, R L; Zeldin, D C

    2001-07-06

    A cDNA encoding a new cytochrome P450 was isolated from a mouse brain library. Sequence analysis reveals that this 1,958-base pair cDNA encodes a 57-58-kDa 502-amino acid polypeptide that is 70-91% identical to CYP2J subfamily P450s and is designated CYP2J9. Recombinant CYP2J9 was co-expressed with NADPH-cytochrome P450 oxidoreductase (CYPOR) in Sf9 cells using a baculovirus system. Microsomes of CYP2J9/CYPOR-transfected cells metabolize arachidonic acid to 19-hydroxyeicosatetraenoic acid (HETE) thus CYP2J9 is enzymologically distinct from other P450s. Northern analysis reveals that CYP2J9 transcripts are present at high levels in mouse brain. Mouse brain microsomes biosynthesize 19-HETE. RNA polymerase chain reaction analysis demonstrates that CYP2J9 mRNAs are widely distributed in brain and most abundant in the cerebellum. Immunoblotting using an antibody raised against human CYP2J2 that cross-reacts with CYP2J9 detects a 56-kDa protein band that is expressed in cerebellum and other brain segments and is regulated during postnatal development. In situ hybridization of mouse brain sections with a CYP2J9-specific riboprobe and immunohistochemical staining with the anti-human CYP2J2 IgG reveals abundant CYP2J9 mRNA and protein in cerebellar Purkinje cells. Importantly, 19-HETE inhibits the activity of recombinant P/Q-type Ca(2+) channels that are known to be expressed preferentially in cerebellar Purkinje cells and are involved in triggering neurotransmitter release. Based on these data, we conclude that CYP2J9 is a developmentally regulated P450 that is abundant in brain, localized to cerebellar Purkinje cells, and active in the biosynthesis of 19-HETE, an eicosanoid that inhibits activity of P/Q-type Ca(2+) channels. We postulate that CYP2J9 arachidonic acid products play important functional roles in the brain.

  5. Arachidonic acid metabolism in TNS-induced chronic and immunologic enteritis in rats, and the effect of 5-ASA

    Directory of Open Access Journals (Sweden)

    F. J. Zijlstra

    1993-01-01

    Full Text Available Inflammation of the rat distal intestine was induced by intradermal sensitization and subsequent multiple intrajejunal challenge with the hapten 2,4,6-trinitrobenzenesulphonic acid (TNBS via an implanted catheter. The time course of the inflammatory reaction was followed by determination of the enteritis score and measurement of in vitro eicosanoid formation of homogenates of the gut after 0, 1, 2, 4, 7, 14 and 21 days of local daily challenge with 0.08% TNBS. There was a small initial increase of eicosanoid formation, reached at days 1 and 2, followed by a significant increase in metabolism of arachidonic acid on day 21. Although at day 1 a four-fold increase in inflammation score was reached, no further significant changes were observed during the following 3 weeks. The greatest increase in metabolite formation was observed in prostanoids TxB2, PGE2. and PGD2 and the 5-lipoxygenase product LTC4, whereas minor changes were found for LTB4 and other lipoxygenase products such as 12- and 15-HETE. The formation of these metabolites was already inhibited by low-dose 5-aminosalicylic acid (5-ASA, given orally twice daily during the 3 weeks challenge period, while the enteritis score was affected dosedependently.

  6. Mechanisms of formation and function of eosinophil lipid bodies: inducible intracellular sites involved in arachidonic acid metabolism

    Directory of Open Access Journals (Sweden)

    Bozza Patricia T

    1997-01-01

    Full Text Available Lipid bodies, inducible lipid-rich cytoplasmic inclusions, are characteristically abundant in cells associated with inflammation, including eosinophils. Here we reviewed the formation and function of lipid bodies in human eosinophils. We now have evidence that the formation of lipid bodies is not attributable to adverse mechanisms, but is centrally mediated by specific signal transduction pathways. Arachidonic acid and other cis fatty acids by an NSAID-inhibitable process, diglycerides, and PAF by a 5-lipoxygenase dependent pathway are potent stimulators of lipid body induction. Lipid body formation develops rapidly by processes that involve PKC, PLC, and de novo mRNA and protein synthesis. These structures clearly serve as repositoires of arachidonyl-phospholipids and are more than inert depots. Specific enzymes, including cytosolic phospholipase A2, MAP kinases, lipoxygenases and cyclooxygenases, associate with lipid bodies. Lipid bodies appear to be dynamic, organelle-like structures involved in intracellular pathways of lipid mobilization and metabolism. Indeed, increases in lipid body numbers correlated with enhanced production of both lipoxygenase- and cyclooxygenase-derived eicosanoids. We hypothesize that lipid bodies are distinct inducible sites for generating eicosanoids as paracrine mediators with varied activities in inflammation. The capacity of lipid body formation to be specifically and rapidly induced in leukocytes enhances eicosanoid mediator formation, and conversely pharmacologic inhibition of lipid body induction represents a potential novel and specific target for anti-inflammatory therapy.

  7. Aureispira marina gen. nov., sp. nov., a gliding, arachidonic acid-containing bacterium isolated from the southern coastline of Thailand.

    Science.gov (United States)

    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. Effects of organometals on cellular signaling. I. Influence of metabolic inhibitors on metal-induced arachidonic acid liberation.

    Science.gov (United States)

    Käfer, A; Krug, H F

    1994-09-01

    Organic lead and tin compounds stimulate an increase of free arachidonic acid (AA) in HL-60 cells. This fatty acid is involved in numerous health problems and physiological mechanisms. Three major pathways result in a liberation of AA from membrane phospholipids and there is evidence that G-proteins serve as couplers within all three pathways. Therefore we investigated the influence of pertussis toxin (PT) on the organometallic-induced AA liberation. The effect of all studied compounds (organotin and organo-lead) was diminished by PT. We conclude that the organometals activate PLA2 to some extent via a PT-sensitive pathway. The ionophor A 23187 (1-10 microM) led to an increase of free AA by raising the intracellular Ca2+ level. One of the postulated ways of AA release is via Ca2+ channel activation; phospholipases are Ca2+ dependent. Thus, we examined the necessity of free intracellular Ca2+ for the organometallic effect. The Ca2+ chelator EGTA inhibited the increase of free AA induced by organometals. This is true also for verapamil, a Ca2+ channel blocker. Quinacrine, which is thought to be an inhibitor of phospholipase A2 (PLA2), prevented the AA liberation from membrane phospholipids induced by organometals. This could be due to the inhibition of PLA2, but it could also be the result of an inhibited Ca2+ influx.

  9. Mechanism of angiotensin II-induced arachidonic acid metabolite release in aortic smooth muscle cells: involvement of phospholipase D.

    Science.gov (United States)

    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.

  10. The effects on plasma, red cell and platelet fatty acids of taking 12 g/day of ethyl-eicosapentaenoate for 16 months : dihomogammalinolenic, arachidonic and docosahexaenoic acids and relevance to Inuit metabolism

    NARCIS (Netherlands)

    Horrobin, David; Fokkema, M Rebecca; Muskiet, Frits A J

    2003-01-01

    A patient with mantle cell lymphoma took 12g/day of ethyl-eicosapentaenoate for 16 months. Compared to reference values, eicosapentaenoic and docosapentaenoic acids were elevated in plasma, red cells and platelets but docosahexaenoic acid levels were in the normal range. Arachidonic acid levels were

  11. Phospholipid, arachidonate and eicosanoid signaling in schizophrenia

    Directory of Open Access Journals (Sweden)

    Messamore Erik

    2016-01-01

    Full Text Available This paper reviews the potential role of arachidonic acid in the pathophysiology of schizophrenia. We discuss how abnormal levels of arachidonic acid may arise, and how dysregulation of signaling molecules derived from it have the potential to disrupt not only dopamine signaling, but numerous other physiological processes associated with the illness. Pharmacological doses of niacin stimulate the release of arachidonic acid; and arachidonic acid-derived molecules in turn dilate blood vessels in the skin. A blunted skin flush response to niacin is reliably observed among patients with schizophrenia. The niacin response abnormality may thus serve as a biomarker to identify a physiological subtype of schizophrenia associated with defective arachidonic acid-derived signaling.

  12. Dietary supplementation of arachidonic acid increases arachidonic acid and lipoxin A4 contents in colon, but does not affect severity or prostaglandin E2 content in murine colitis model

    Science.gov (United States)

    2014-01-01

    Background Arachidonic acid (ARA) is an essential fatty acid and a major constituent of biomembranes. It is converted into various lipid mediators, such as prostaglandin E2 (PGE2) and lipoxin A4 (LXA4). The effects of dietary ARA on colon maintenance are unclear because PGE2 has both mucosal protective and proinflammatory effects, and LXA4 has an anti-inflammatory role. Our objective is to clarify the effects of dietary ARA on an experimental murine colitis model. Methods C57BL/6 mice were fed three types of ARA diet (0.075%, 0.15% or 0.305% ARA in diet), DHA diet (0.315% DHA) or control diet for 6 weeks, and were then administered dextran sodium sulphate (DSS) for 7 days to induce colitis. We evaluated colitis severity, fatty acid and lipid mediator contents in colonic tissue, and the expression of genes related to lipid mediator formation. Results ARA composition of colon phospholipids was significantly elevated in an ARA dose-dependent manner. ARA, as well as DHA, did not affect colitis severity (body weight loss, colon shortening, diarrhea and hemoccult phenomena) and histological features. PGE2 contents in the colon were unchanged by dietary ARA, while LXA4 contents increased in an ARA dose-dependent manner. Gene expression of cyclooxygenase (COX)-1 and COX-2 was unchanged, while that of 12/15-lipoxgenase (LOX) was significantly increased by dietary ARA. ARA composition did not correlate with neither colon length nor PGE2 contents, but significantly correlated with LXA4 content. Conclusion These results suggest that dietary ARA increases ARA and LXA4 contents in colon, but that it has no effect on severity and PGE2 content in a DSS-induced murine colitis model. PMID:24507383

  13. COX-2, aspirin and metabolism of arachidonic, eicosapentaenoic and docosahexaenoic acids and their physiological and clinical significance.

    Science.gov (United States)

    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.

  14. Arachidonic acid drives postnatal neurogenesis and elicits a beneficial effect on prepulse inhibition, a biological trait of psychiatric illnesses.

    Directory of Open Access Journals (Sweden)

    Motoko Maekawa

    Full Text Available Prepulse inhibition (PPI is a compelling endophenotype (biological markers for mental disorders including schizophrenia. In a previous study, we identified Fabp7, a fatty acid binding protein 7 as one of the genes controlling PPI in mice and showed that this gene was associated with schizophrenia. We also demonstrated that disrupting Fabp7 dampened hippocampal neurogenesis. In this study, we examined a link between neurogenesis and PPI using different animal models and exploring the possibility of postnatal manipulation of neurogenesis affecting PPI, since gene-deficient mice show biological disturbances from prenatal stages. In parallel, we tested the potential for dietary polyunsaturated fatty acids (PUFAs, arachidonic acid (ARA and/or docosahexaenoic acid (DHA, to promote neurogenesis and improve PPI. PUFAs are ligands for Fabp members and are abundantly expressed in neural stem/progenitor cells in the hippocampus. Our results are: (1 an independent model animal, Pax6 (+/- rats, exhibited PPI deficits along with impaired postnatal neurogenesis; (2 methylazoxymethanol acetate (an anti-proliferative drug elicited decreased neurogenesis even in postnatal period, and PPI defects in young adult rats (10 weeks when the drug was given at the juvenile stage (4-5 weeks; (3 administering ARA for 4 weeks after birth promoted neurogenesis in wild type rats; (4 raising Pax6 (+/- pups on an ARA-containing diet enhanced neurogenesis and partially improved PPI in adult animals. These results suggest the potential benefit of ARA in ameliorating PPI deficits relevant to psychiatric disorders and suggest that the effect may be correlated with augmented postnatal neurogenesis.

  15. Upregulated expression of brain enzymatic markers of arachidonic and docosahexaenoic acid metabolism in a rat model of the metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Taha Ameer Y

    2012-10-01

    Full Text Available Abstract Background In animal models, the metabolic syndrome elicits a cerebral response characterized by altered phospholipid and unesterified fatty acid concentrations and increases in pro-apoptotic inflammatory mediators that may cause synaptic loss and cognitive impairment. We hypothesized that these changes are associated with phospholipase (PLA2 enzymes that regulate arachidonic (AA, 20:4n-6 and docosahexaenoic (DHA, 22:6n-6 acid metabolism, major polyunsaturated fatty acids in brain. Male Wistar rats were fed a control or high-sucrose diet for 8 weeks. Brains were assayed for markers of AA metabolism (calcium-dependent cytosolic cPLA2 IVA and cyclooxygenases, DHA metabolism (calcium-independent iPLA2 VIA and lipoxygenases, brain-derived neurotrophic factor (BDNF, and synaptic integrity (drebrin and synaptophysin. Lipid concentrations were measured in brains subjected to high-energy microwave fixation. Results The high-sucrose compared with control diet induced insulin resistance, and increased phosphorylated-cPLA2 protein, cPLA2 and iPLA2 activity and 12-lipoxygenase mRNA, but decreased BDNF mRNA and protein, and drebrin mRNA. The concentration of several n-6 fatty acids in ethanolamine glycerophospholipids and lysophosphatidylcholine was increased, as was unesterified AA concentration. Eicosanoid concentrations (prostaglandin E2, thromboxane B2 and leukotriene B4 did not change. Conclusion These findings show upregulated brain AA and DHA metabolism and reduced BDNF and drebrin, but no changes in eicosanoids, in an animal model of the metabolic syndrome. These changes might contribute to altered synaptic plasticity and cognitive impairment in rats and humans with the metabolic syndrome.

  16. Involvement of Oxidative Stress and Down-Regulation of Bcl-2 in Arachidonic Acid-Induced Apoptosis in HUVECs

    Institute of Scientific and Technical Information of China (English)

    WANG Bing-hua; WANG Yun; CHEN Li-da; CAO Jin-xiu; ZHOU Wen-jing

    2005-01-01

    Human umbilical vein endothelial cells (HUVECs) were treated with arachidonic acid (AA). After 24 h exposure to AA, typical morphological changes of apoptosis were observed by Giemsa stain and transmission electron microscopy. The apoptotic ratio in HUVECs treated with 50 μmol/L, 100 μmol/L and 150 μmol/L AA were (20.7±3.6) %, (38.6±4.3) % and (52.5±7.5) % respectively. Contrarily, low concentration of AA (≤25 μmol/L) exerted no influence on cell viability by MTT assay. Intracellular malondialdehyde increased significantly in a dose-dependent manner upon AA treatment and the opposite tendency was found for the reduced glutathione. Western Blots show that apoptosis triggered by AA was associated with the down-regulation of Bcl-2 expression, but not with Bax and p53. Pretreatment with 50 μmol/L α-tocopherol reduced AA-induced oxidative stress and apoptosis, also inhibited the down-regulation of Bcl-2/Bax ratio. These results suggested that high concentration of free AA could induce apoptosis in HUVECs probably via oxidative stress and down-regulation of Bcl-2.

  17. [Effect of dauricine on rat and human platelet aggregation and metabolism of arachidonic acid in washed rat platelets].

    Science.gov (United States)

    Tong, L; Yue, T L

    1989-01-01

    Dauricine (Dau), an isoquinoline alkaloid extracted from the roots of Menispermum dauricum D. C. and used as an antiarrhythmic agent in China recently, was shown to inhibit rat platelet aggregation induced by arachidonic acid (AA) and ADP, as well as human platelet aggregation induced by AA, ADP and adrenaline (Adr) in vitro in a dose-dependent manner. The concentration of Dau required for 50% inhibition (IC50) of rat platelet aggregation induced by AA and ADP was 26 and 37 mumol/L, respectively. For human platelet aggregation induced by AA, ADP and Adr the IC50 of Dau was found to be 39, 55 and 43 mumol/L, respectively. Dau inhibited the cyclooxygenase pathway metabolites of AA (TXB2 and HHT) in washed intact rat platelets. The production of TXB2 and HHT was reduced by 26% and 19%, respectively, when the Dau concentration was 50 mumol/L and by 46 and 45%, respectively, when the concentration of Dau was 100 mumol/L. The formation of 12-HETE was also inhibited at 100 mumol/L of Dau. The inhibitory effect of Dau on AA metabolism may be one of the mechanisms related to its inhibition of platelet aggregation.

  18. The effect of basic fibroblast growth factor on glutamate-injured neuroarchitecture and arachidonic acid release in adult hippocampal neurons.

    Science.gov (United States)

    Himmelseher, S; Pfenninger, E; Georgieff, M

    1996-01-22

    During development in culture, basic fibroblast growth factor (bFGF) protected immature primary hippocampal neurons against glutamate-induced neurotoxicity. We investigated the effects of bFGF on mature, differentiated rat hippocampal neurons cultured for 10-12 days after an 8-min exposure to 500 microM glutamate. Seven days post-injury, hippocampal cells demonstrated severe reductions in cellular viability and axonal and dendritic outgrowth, which were accompanied by a marked increase in [3H]arachidonic acid (ARA) release from prelabelled neurons. bFGF applied post-injury attenuated cell death and cytoarchitectural destruction at all concentrations used (500 pg/ml, 1, 10, 20 ng/ml). However, neurite elongation and branching processes were only significantly protected by 10 ng/ml bFGF. [3H]ARA release decreased in a dose-related fashion within a concentration range of 1-10 ng/ml bFGF. 20 ng/ml bFGF was not superior to 10 ng/ml bFGF. Therefore, bFGF's neurotropic actions appear to be concentration-dependent. Our data suggest that bFGF applied post-injury may have a neuroprotective potential for mature, differentiated, completely polarized hippocampal neurons.

  19. SIRT1 prevents pulmonary thrombus formation induced by arachidonic acid via downregulation of PAF receptor expression in platelets.

    Science.gov (United States)

    Kim, Yun Hak; Bae, Jin Ung; Kim, In Suk; Chang, Chulhun L; Oh, Sae Ock; Kim, Chi Dae

    2016-12-01

    SIRT1, a class III histone deacetylase, is critically involved in cellular response to stress and modulates cardiovascular risk factors. However, its role in thrombus formation is largely unknown. Thus, this study investigated the effect of SIRT1 on pulmonary thrombus formation, and then identified its role in the modulation of platelet aggregation. In isolated human platelets, cell aggregation was increased by various platelet activators, such as platelet activating factor (PAF), arachidonic acid (AA), ADP, and thrombin. AA- and PAF-mediated platelet aggregations were suppressed by WEB2086, a PAF receptor (PAFR) antagonist. Pulmonary thrombus formation induced by PAF or AA was also attenuated by WEB2086, suggesting that PAFR plays a key role in AA-induced platelet aggregation. In platelets isolated from SIRT1-TG mice as well as in platelets treated with resveratrol or reSIRT1, PAFR expression was decreased, whereas this expressional downregulation by SIRT1 activators was inhibited in platelets treated with MG132 (a proteasome inhibitor) or NH4Cl (a lysosome inhibitor). Furthermore, platelet aggregation induced by AA was markedly attenuated by resveratrol and reSIRT1. Likewise, the increased pulmonary thrombus formation in mice treated with AA was also attenuated by SIRT1 activators. In line with these results, pulmonary thrombus formation was markedly attenuated in SIRT1-TG mice. Taken together, this study showed that SIRT1 downregulates PAFR expression on platelets via proteasomal and lysosomal pathways, and that this downregulation inhibits platelet aggregation in vitro and pulmonary thrombus formation in vivo.

  20. Lipid droplets in activated mast cells - a significant source of triglyceride-derived arachidonic acid for eicosanoid production.

    Science.gov (United States)

    Dichlberger, Andrea; Schlager, Stefanie; Kovanen, Petri T; Schneider, Wolfgang J

    2016-08-15

    Mast cells are potent effectors of immune reactions and key players in various inflammatory diseases such as atherosclerosis, asthma, and rheumatoid arthritis. The cellular defense response of mast cells represents a unique and powerful system, where external signals can trigger cell activation resulting in a stimulus-specific and highly coordinated release of a plethora of bioactive mediators. The arsenal of mediators encompasses preformed molecules stored in cytoplasmic secretory granules, as well as newly synthesized proteinaceous and lipid mediators. The release of mediators occurs in strict chronological order and requires proper coordination between the endomembrane system and various enzymatic machineries. For the generation of lipid mediators, cytoplasmic lipid droplets have been shown to function as a major intracellular pool of arachidonic acid, the precursor for eicosanoid biosynthesis. Recent studies have revealed that not only phospholipids in mast cell membranes, but also triglycerides in mast cell lipid droplets are a substrate source for eicosanoid formation. The present review summarizes current knowledge about mast cell lipid droplet biology, and discusses expansions and challenges of traditional mechanistic models for eicosanoid production.

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

    Science.gov (United States)

    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.

  2. Coordination of gene expression of arachidonic and docosahexaenoic acid cascade enzymes during human brain development and aging.

    Directory of Open Access Journals (Sweden)

    Veronica H Ryan

    Full Text Available The polyunsaturated arachidonic and docosahexaenoic acids (AA and DHA participate in cell membrane synthesis during neurodevelopment, neuroplasticity, and neurotransmission throughout life. Each is metabolized via coupled enzymatic reactions within separate but interacting metabolic cascades.AA and DHA pathway genes are coordinately expressed and underlie cascade interactions during human brain development and aging.The BrainCloud database for human non-pathological prefrontal cortex gene expression was used to quantify postnatal age changes in mRNA expression of 34 genes involved in AA and DHA metabolism.Expression patterns were split into Development (0 to 20 years and Aging (21 to 78 years intervals. Expression of genes for cytosolic phospholipases A2 (cPLA2, cyclooxygenases (COX-1 and -2, and other AA cascade enzymes, correlated closely with age during Development, less so during Aging. Expression of DHA cascade enzymes was less inter-correlated in each period, but often changed in the opposite direction to expression of AA cascade genes. Except for the PLA2G4A (cPLA2 IVA and PTGS2 (COX-2 genes at 1q25, highly inter-correlated genes were at distant chromosomal loci.Coordinated age-related gene expression during the brain Development and Aging intervals likely underlies coupled changes in enzymes of the AA and DHA cascades and largely occur through distant transcriptional regulation. Healthy brain aging does not show upregulation of PLA2G4 or PTGS2 expression, which was found in Alzheimer's disease.

  3. Effect of dietary fat saturation on lipid metabolism, arachidonic acid turnover and peritoneal macrophage oxidative stress in mice

    Directory of Open Access Journals (Sweden)

    L.B. Oliveros

    2004-03-01

    Full Text Available We investigated the effects of a saturated fat diet on lipid metabolism and arachidonic acid (AA turnover in mouse resident peritoneal macrophages. The pro-oxidative effect of this diet was also studied. Female C57BL/6 mice were weaned at 21 days of age and assigned to either the experimental diet containing coconut oil (COCO diet, or the control diet containing soybean oil as fat source (10 mice per group. The fat content of each diet was 15% (w/w. Mice were fed for 6 weeks and then sacrificed. The concentration of total lipids, triglycerides, (LDL + VLDL-cholesterol, thiobarbituric acid-reactive substances (TBARS and reduced glutathione were increased in the plasma of mice fed the COCO diet, without changes in phospholipid or total cholesterol concentrations compared to control. The concentrations of total cholesterol, free and esterified cholesterol, triglycerides, and TBARS were increased in the macrophages of COCO-fed mice, while the content of total phospholipids did not change. The phospholipid composition showed an increase of phosphatidylcholine and a decrease of phosphatidylethanolamine. The [³H]-AA distribution in the phospholipid classes showed an increase in phosphatidylcholine and phosphatidylethanolamine. Incorporation of [³H]-cholesterol into the macrophages of COCO-fed mice and into the cholesterol ester fraction was increased. The COCO diet did not affect [³H]-AA uptake but induced an increase in [³H]-AA release. The COCO diet also enhanced AA mobilization induced by lipopolysaccharide. These results indicate that the COCO diet, high in saturated fatty acids, alters the lipid metabolism and AA turnover of peritoneal macrophages in female mice and also produces a significant degree of oxidative stress.

  4. Production of arachidonic acid metabolites by macrophages exposed in vitro to asbestos, carbonyl iron particles, or calcium ionophore.

    Science.gov (United States)

    Kouzan, S; Brody, A R; Nettesheim, P; Eling, T

    1985-04-01

    Consequent to asbestos deposition, alveolar macrophages (AM) accumulate at alveolar duct bifurcations where they phagocytize fibers. Because phagocytosis can stimulate the release of arachidonic acid (AA) metabolites, the possibility that secretion of these powerful mediators of inflammation might be induced by chrysotile asbestos was investigated in vitro. Rat AM were treated in vitro with chrysotile asbestos, and the cyclooxygenase products--prostaglandins, thromboxane B2 (TXB2), 12-hydroxy-5,8,10-heptadecatrienoic acid (HHT)--and lipoxygenase products--leukotrienes (LT), hydroxyeicosatetraenoic acids (HETE)--secreted in the medium were isolated by high-performance liquid chromatography. Composition of the AA metabolites released was compared with that from those stimulated by the calcium ionophore A 23187 (20 microM) and by another particulate phagocytic stimulus, i.e., carbonyl iron beads. Calcium ionophore stimulation induced a marked release of various AA metabolites in the medium from both the cyclooxygenase pathway (HHT, TXB2, and PGE2, in decreasing quantities, respectively) and the lipoxygenase pathway (LTB4, 5-HETE, 12-HETE, and LTC4). The major product was LTB4. Treatment of the macrophages with asbestos fibers induced the release of a similar array of AA metabolites, although there were smaller amounts of LTC4 and 12-HETE, but increased quantities of PGF2 alpha. A time course study showed a steady increase in metabolite production for 1 h, followed by a plateau. In addition, the amount of metabolites released was dependent on asbestos concentrations. Phagocytosis of iron beads induced the secretion of the same metabolites as asbestos stimulation, but in larger quantities, probably reflecting the lack of cytotoxicity of the particle.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Role of arachidonic acid in hyposmotic membrane stretch-induced increase in calcium-activated potassium currents in gastric myocytes

    Institute of Scientific and Technical Information of China (English)

    Meng YANG; Wen-xie XU; Xing-lan LI; Hui-ying XU; Jia-bin SUN; Bin MEI; Hai-feng ZHENG; Lian-hua PIAO; De-gang XING; Zhai-liu LI

    2005-01-01

    Aim: To study effects of arachidonic acid (AA) and its metabolites on the hyposmotic membrane stretch-induced increase in calcium-activated potassium currents (IKCa) in gastric myocytes. Methods: Membrane currents were recorded by using a conventional whole cell patch-clamp technique in gastric myocytes isolated with collagenase. Results: Hyposmotic membrane stretch and AA increased both IK(Ca) and spontaneous transient outward currents significantly.Exogenous AA could potentiate the hyposmotic membrane stretch-induced increase in IK(Ca). The hyposmotic membrane stretch-induced increase in IK(Ca) was significantly suppressed by dimethyleicosadienoic acid (100 μmol/L in pipette solution), an inhibitor of phospholipase A2. Nordihydroguaiaretic acid, a lipoxygenase inhibitor, significantly suppressed AA and hyposmotic membrane stretch-induced increases in IK(Ca). External calcium-free or gadolinium chloride, a blocker of stretch-activated channels, blocked the AA-induced increase in IK(Ca) significantly, but it was not blocked by nicardipine, an L-type calcium channel blocker. Ryanodine, a calcium-induced calcium release agonist, completely blocked the AA-induced increase in IK(Ca); however, heparin, a potent inhibitor of inositol triphosphate receptor, did not block the AA-induced increase in IK(Ca). Conclusion:Hyposmotic membrane stretch may activate phospholipase A2, which hydrolyzes membrane phospholipids to ultimately produce AA; AA as a second messenger mediates Ca2+ influx, which triggers Ca2+-induced Ca2+ release and elicits activation of IK(Ca) in gastric antral circular myocytes of the guinea pig.

  6. Hydroxyurea Therapy Mobilises Arachidonic Acid from Inner Cell Membrane Aminophospholipids in Patients with Homozygous Sickle Cell Disease

    Directory of Open Access Journals (Sweden)

    A. A. Daak

    2011-01-01

    Full Text Available The cytotoxic compound hydroxyurea (HU is effective therapy for sickle cell disease. However, its effect on unsaturated membrane lipids is unknown. Red cell fatty acids were investigated in HU-treated (n=19 and HU-untreated (n=17 sickle cell patients and controls (n=20. The HU-treated compared with the HU-untreated patients had lower arachidonic (AA acid level in ethanolamine, physphoglycerids (EPG (22.9±1.2   versus   24.0±1.1%,  P<0.05 serine SPG (22.13±2.2   versus   24.9±2.3%,  P<0.01 phosphoglycerides. The treated patients and controls had comparable levels of docosahexaenoic (DHA and total n-3 fatty acids in EPG and choline phosphoglycerides (CPG. In contrast, the untreated group had significantly (P<0.05 lower DHA and total n-3 compared with the controls in EPG (2.7±0.4   versus   3.2±0.6% and 4.6±0.5   versus   5.2±0.7% and CPG (0.7±0.2   versus   1.0±0.2% and 1.2±0.2   versus   1.4±0.3. HU is known to activate cytosolic phospholipase A2 and cyclooxygenase 2, and from this study, it appears to induce mobilisation of AA from the inner cell membrane EPG and SPG. Hence, eicosanoids generated from the released AA may play a role in clinical improvements which occur in HU-treated patients.

  7. Differential age- and disease-related effects on the expression of genes related to the arachidonic acid signaling pathway in schizophrenia.

    Science.gov (United States)

    Tang, Bin; Capitao, Cristina; Dean, Brian; Thomas, Elizabeth A

    2012-04-30

    We have previously identified differential effects of age on global brain gene expression profiles in subjects with schizophrenia compared to normal controls. Here, we have focused on age-related effects of genes associated with the arachidonic acid-related inflammation pathway. Linear correlation analysis of published microarray expression data reveal strong age- and cell-type- specific-effects on the expression of genes related to the arachidonic acid signaling pathway, which differed in control subjects compared to those with schizophrenia. Using real-time qPCR analysis, we validated age and disease effects of arachidonic acid-related genes in a large cohort of subjects with schizophrenia and matched controls (n=76 subjects in total). We found that levels of prostaglandin-endoperoxide synthase 1 (PTGS1; aka COX-1) and prostaglandin-endoperoxide receptor 3 (PTGER3) mRNA are increased, and levels of prostaglandin-endoperoxide synthase 2 (PTGS2; aka COX-2) mRNA are decreased, in older subjects with schizophrenia (> 40years of age) compared to matched normal controls or younger subjects with schizophrenia (schizophrenia and further suggest that age may be an important factor in the potential use of anti-inflammatory therapies.

  8. Roles of phospholipase A2 isoforms in swelling- and melittin-induced arachidonic acid release and taurine efflux in NIH3T3 fibroblasts

    DEFF Research Database (Denmark)

    Pedersen, Stine Helene Falsig; Poulsen, Kristian Arild; Lambert, Ian H.

    2006-01-01

    Osmotic swelling of NIH3T3 mouse fibroblasts activates a bromoenol lactone (BEL)-sensitive taurine efflux, pointing to the involvement of a Ca2+-independent phospholipase A2 (iPLA2) (Lambert IH. J Membr Biol 192: 19-32, 2003). We report that taurine efflux from NIH3T3 cells was not only increased......-induced PLA2 activity was also detected in lysates devoid of sPLA2, indicating that both sPLA2 and iPLA2 contribute to arachidonic acid release in vivo. Swelling-induced taurine efflux was inhibited potently by BEL and partially by manoalide, whereas the reverse was true for melittin-induced taurine efflux....... It is suggested that in NIH3T3 cells, swelling-induced taurine efflux is dependent at least in part on arachidonic acid release by iPLA2 and possibly also by sPLA2, whereas melittin-induced taurine efflux is dependent on arachidonic acid release by sPLA2 and, to a lesser extent, iPLA2....

  9. Blockade by metal complexing agents and by catalase of the effects of arachidonic acid on platelets: relevance to the study of anti-inflammatory mechanisms.

    Science.gov (United States)

    Vargaftig, B B; Tranier, Y; Chignard, M

    1975-08-01

    Metal-chelating agents inhibited platelet aggregation and the accompanying generation of rabbit aorta contracting and PG-like activities, when platelets were challenged with arachidonic acid. Inhibition required the presence of the chelating agents in the medium, and was insured by reagents avid for free or protein-bound copper. Catalase also prevented aggregation and generation of pharmacologically active substances; its activity was reversed by aminothiol agents and by Cu2+ and Zn2+, shown previously to potentiate the platelet effects of arachidonic acid. Inhibition by indomethacin was not prevented by amino-thiol drugs nor by Cu2+ or Zn2+. The catalase-induced inhibition was not affected by scavenging of thiol groups; this rules out, as a mechanism of action of catalase, the increased destruction of popoperoxides by glutathione peroxidase, which requires reduced glutathione as hydrogen donor. The results are compatible with the hypothesis that the agent that mediates platelet aggregation by arachidonic acid is a popoperoxide, requiring the presence either of H2O2 or of a similarly catalase-sensitive substance to be generated.

  10. 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

    Science.gov (United States)

    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

  11. The influence of dietary concentrations of arachidonic acid and eicosapentaenoic acid at various stages of larval ontogeny on eye migration, pigmentation and prostaglandin content of common sole larvae ( Solea solea L.)

    DEFF Research Database (Denmark)

    Lund, Ivar; Steenfeldt, Svend Jørgen; Banta, G.;

    2008-01-01

    Dietary manipulations of arachidonic acid, ARA and eicosapentaenoic acid, EPA may have an influence on pigmentation in common sole larvae (Solea solea L., Linnaeus 1758) which may be related to a "pigmentation window". This is a specific period in the larval ontogeny where nutritional factors...

  12. Novel liquid chromatography–mass spectrometry method shows that vitamin E deficiency depletes arachidonic and docosahexaenoic acids in zebrafish (Danio rerio embryos

    Directory of Open Access Journals (Sweden)

    Katie M. Lebold

    2014-01-01

    Full Text Available To test the hypothesis that embryogenesis depends upon α-tocopherol (E to protect embryo polyunsaturated fatty acids (PUFAs from lipid peroxidation, new methodologies were applied to measure α-tocopherol and fatty acids in extracts from saponified zebrafish embryos. A solid phase extraction method was developed to separate the analyte classes, using a mixed mode cartridge (reverse phase, π–π bonding, strong anion exchange, then α-tocopherol and cholesterol were measured using standard techniques, while the fatty acids were quantitated using a novel, reverse phase liquid chromatography–mass spectrometry (LC–MS approach. We also determined if α-tocopherol status alters embryonic lipid peroxidation products by analyzing 24 different oxidized products of arachidonic or docosahexaenoic (DHA acids in embryos using LC with hybrid quadrupole-time of flight MS. Adult zebrafish were fed E− or E+ diets for 4 months, and then were spawned to obtain E− and E+ embryos. Between 24 and 72 hours post-fertilization (hpf, arachidonic acid decreased 3-times faster in E− (21 pg/h compared with E+ embryos (7 pg/h, P<0.0001, while both α-tocopherol and DHA concentrations decreased only in E− embryos. At 36 hpf, E− embryos contained double the 5-hydroxy-eicosatetraenoic acids and 7-hydroxy-DHA concentrations, while other hydroxy-lipids remained unchanged. Vitamin E deficiency during embryogenesis depleted DHA and arachidonic acid, and increased hydroxy-fatty acids derived from these PUFA, suggesting that α-tocopherol is necessary to protect these critical fatty acids.

  13. Effect of some saturated and unsaturated fatty acids on prostaglandin biosynthesis in washed human blood platelets from (1-/sup 14/ C)arachidonic acid

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, K.C.; Awasthi, K.K.; Lindegard, P.; Tiwari, K.P.

    1982-03-01

    The effects of some saturated (lauric, palmitic and stearic) an unsaturated (linoleic, gamma-linolenic, alpha-linolenic and oleic) fatty acids at 0.1. 0.25 and 0.5 mM concentrations on the in vitro metabolization of (1-14 C) arachidonic acid by washed human blood platelets have been studied. Effects of these fatty acids were studied with intact as well as lysed platelet preparations. With intact platelet preparations it was found that (i) all unsaturated fatty acids enhanced the biosynthesis of TxB2, PGE2, PGD2 and PGF2 alpha, (ii) unsaturated fatty acids reduced the formation of HHT and HETE with the exception of oleic acid which showed very little effect, (iii) unsaturated fatty acids reduced the formation of MDA, whereas palmitic and stearic acids increased its formation and (iv) all unsaturated fatty acids reduced the synthesis of prostaglandin endoperoxides. These results support our previous observations where effects of fatty acids were examined at higher concentrations (10). At 0.1 mM FA concentration, inconsistent results were obtained. With lysed platelet preparations all cyclooxygenase products were reduced in presence of unsaturated fatty acids, whereas HETE formation was reduced only in presence of linoleic and gamma-linolenic acids. Electron micrographs of washed platelet suspensions were obtained with untreated platelet preparations and platelet preparations treated with 0.25 and 0.5 mM linoleic acid concentrations. The results are discussed in the light of a possible soap-like effect of FA salt on platelets.

  14. Scale-up cultivation enhanced arachidonic acid accumulation by red microalgae Porphyridium purpureum.

    Science.gov (United States)

    Chang, Jingyu; Le, Kai; Song, Xiaoqiang; Jiao, Kailin; Zeng, Xianhai; Ling, Xueping; Shi, Tuo; Tang, Xing; Sun, Yong; Lin, Lu

    2017-08-23

    The present study attempts to cultivate Porphyridium purpureum under different scale-up conditions for further development and commercialization of microalgae-derived PUFAs such as ARA and EPA. Different temperatures (25, 30, and 35 °C) and light intensities (70, 165, and 280 μmol/m(2)s) were applied to the 50 L pilot-scale cultivation of P. purpureum in ASW. The cultivation under the light intensity of 280 μmol/m(2)s at 35 °C obtained biomass concentration up to 9.52 g/L, total fatty acid content to 56.82 mg/g, and ARA content to 22.29 mg/g. While the maximum EPA content of 7.00 mg/g was achieved under the light intensity of 280 μmol/m(2)s at 25 °C and the highest ratio of UFAs to TFAs of 74.66% was also obtained in this trial. Both biomass concentration and TFAs content were improved by increasing light intensity and temperature. Moreover, the ratio of ARA to EPA was enhanced by increasing cultivation temperature under the light intensity of 280 μmol/m(2)s. In contrast with flask culture, the conversion of linoleic acid (C18:2) to ARA was enhanced in scale-up culture, leading to more ARA content. Phosphate limitation enhanced the synthesis of lipid and LPUFAs. Moreover, the biomass concentration and biosynthesis of palmitic acid were preferred by sufficient C (NaHCO3).

  15. Associations between dietary n-6 and n-3 fatty acids and arachidonic acid compositions in plasma and erythrocytes in young and elderly Japanese volunteers

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    Kawabata Terue

    2011-08-01

    Full Text Available Abstract Background We reported that the compositions of arachidonic acid (ARA in erythrocytes and plasma phospholipids (PL in the elderly were lower than those in the young, though the ARA intake was nearly identical. Objective We further analyzed data in four study groups with different ages and sexes, and determined that the blood ARA levels were affected by the kinds of dietary fatty acids ingested. Methods One hundred and four healthy young and elderly volunteers were recruited. Dietary records together with photographic records from 28 consecutive days were reviewed and the fatty acid composition in plasma lipid fractions and erythrocyte PL was analyzed. Results No correlations for ARA between dietary fatty acids and blood lipid fractions were observed. A significant negative correlation between eicosapentaenoic acid (EPA + docosahexaenoic acid (DHA intake and ARA composition in erythrocyte PL was observed. ARA composition in erythrocyte PL was significantly lower in elderly subjects than in young subjects, because EPA and DHA intake in elderly subjects was higher than in young subjects. However, after removing the effect of dietary EPA+DHA intake, the ARA composition in erythrocyte PL in elderly subjects was significantly lower than that in young subjects. Conclusions Changes in physical conditions with aging influenced the low ARA composition of erythrocyte in elderly subjects in addition to the effects of dietary EPA and DHA.

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

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    Eduardo O De Souza

    Full Text Available 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.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.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.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.

  17. Mechanisms for the formation of isoprostane endoperoxides from arachidonic acid. "Dioxetane" intermediate versus beta-fragmentation of peroxyl radicals.

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    Yin, Huiyong; Havrilla, Christine M; Gao, Ling; Morrow, Jason D; Porter, Ned A

    2003-05-09

    The isoprostanes are a class of autoxidation products generated from arachidonic acid (or its esters) by a free radical initiated process. The potent biological activity of these compounds has been attracting intense research interest since they were detected in humans as well as animal models in the early 1990s. The measurement of these compounds has been regarded as one of the most useful non-invasive biomarkers for oxidative stress status. Two mechanisms for the formation of these compounds have been proposed. In the first mechanism, a peroxyl radical undergoes successive 5-exo cyclizations analogous to the enzymatic mechanism proposed for prostaglandin biosynthesis. The second mechanism starts with a 4-exo cyclization of a peroxyl radical leading to an intermediate dioxetane, a mechanism that has also been proposed for prostaglandin biosynthesis as well as for the formation of 4-hydroxy nonenal (HNE). Autoxidation of cholesteryl-15-HpETE under free radical conditions provides Type IV isoprostanes. The "dioxetane" mechanism for isoprostane generation from 15-HpETE requires that optically pure products are formed from an optically pure reactant, whereas an alternate mechanism for the process involving beta-fragmentation of the 15-peroxyl would give racemic isoprostane products. We have carried out a test of the mechanism based upon these stereochemical requirements. The results of analysis of the product mixture derived from autoxidation of optically pure Ch-15-HpETE by atmospheric pressure chemical ionization-mass spectrometry coupled with chiral high performance liquid chromatography indicate that the major isoprostane diastereomers are formed as a racemic mixture. These experimental results are consistent with a mechanism for isoprostane formation involving beta-fragmentation of the 15-peroxyl radical followed by re-addition of oxygen to form the 11-HPETE peroxyl, and they exclude a mechanism proceeding through the formation of a dioxetane intermediate.

  18. How dietary arachidonic- and docosahexaenoic- acid rich oils differentially affect the murine hepatic transcriptome

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    Roberts Matthew A

    2006-04-01

    Full Text Available Introduction Herein, we expand our previous work on the effects of long chain polyunsaturated fatty acids (LC-PUFA on the murine hepatic transcriptome using novel statistical and bioinformatic approaches for evaluating microarray data. The analyses focuses on key differences in the transcriptomic response that will influence metabolism following consumption of FUNG (rich in 20:4n6, FISH (rich in 20:5n3, 22:5n3, and 22:6n3 and COMB, the combination of the two. Results Using a variance-stabilized F-statistic, 371 probe sets (out of 13 K probe sets in the Affymetrix Mu11K chip set were changed by dietary treatment (P Conclusion Distinct transcriptomic, signaling cascades, and predicted affects on murine liver metabolism have been elucidated for 20:4n6-rich dietary oils, 22:6n3-rich oils, and a surprisingly distinct set of genes were affected by the combination of the two. Our results emphasize that the balance of dietary n6 and n3 LC-PUFA provided for infants and in nutritional and neutraceutical applications could have profoundly different affects on metabolism and cell signaling, beyond that previously recognized.

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

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    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.

  20. Leukotrienes and other lipoxygenase products of arachidonic acid synthesized in the kidney.

    Science.gov (United States)

    Ardaillou, R; Baud, L; Sraer, J

    1986-08-25

    Lipoxygenase products are synthesized in the kidney. Rabbit medulla and murine and human glomeruli produce 12- and 15-hydroxy-5,8,10,14-eicosatetraenoic acid (HETE). Minor amounts of leukotrienes are formed under normal conditions, but it is likely that the resident renal cells are capable of synthesizing these metabolites. Rat glomeruli and papillae possess the enzymes necessary to process leukotriene C4 into leukotrienes D4 and E4. However, the enzyme activity of the papillae is masked due to the presence of an inhibitor detected in the 10,000 g supernate of the papillary homogenate. 12-HETE synthesis is markedly increased in glomeruli from rats with nephrotoxic serum nephritis and leukotriene B4 synthesis in glomeruli from rats with cationic bovine gamma-globulin-induced glomerulonephritis. In vivo consequences of the association between the resident glomerular cells and the bone marrow-derived cells have been studied in vitro in co-incubation experiments. Glomeruli release factors that stimulate the cyclo-oxygenase and lipoxygenase pathways in macrophages. Co-incubation of glomeruli, platelets, and polymorphonuclear leukocytes results in the formation of 12,20-diHETE and an excess of 12-HETE. Lipoxygenase products, regardless of their origin, modify the renal functions. Leukotriene C4 binds specifically to rat glomeruli and human cultured glomerular epithelial cells. Leukotrienes C4 or D4 administered in vivo cause renal vasoconstriction and a decline in the glomerular filtration rate. In vitro, these two sulfidopeptide leukotrienes promote epithelial cell proliferation and produce mesangial cell contraction. The lipoxygenase pathway is also implicated in the attachment of macrophages to glomeruli and in the oxidative burst of glomerular mesangial cells during phagocytosis. The future use of specific inhibitors of the synthesis or antagonists of the lipoxygenase products, particularly the leukotrienes, should provide a tool for evaluating the role of these

  1. Arachidonic acid has a dominant effect to regulate lipogenic genes in 3T3-L1 adipocytes compared to omega-3 fatty acids

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    Hitesh Vaidya

    2015-03-01

    Full Text Available Background: The effects of long-chain n-3 and n-6 polyunsaturated fatty acids (PUFA on the regulation of adipocytes metabolism are well known. These fatty acids are generally consumed together in our diets; however, the metabolic regulation of adipocytes in the presence of these fatty acids when given together is not known. Objective: To investigate the effects of n-3 PUFA and arachidonic acid (AA, an n-6 PUFA, on the regulation of adipogenic and lipogenic genes in mature 3T3-L1 adipocytes. Methods: 3T3-L1 adipocytes were incubated in the presence or absence of 100 µM of eicosapentaenoic acid, EPA; docosahexaenoic acid, DHA; docosapentaenoic acid, DPA and AA, either alone or AA+n-3 PUFA; control cells received bovine serum albumin alone. The mRNA expression of adipogenic and lipogenic genes was measured. The fatty acid composition of adipocytes was analyzed using gas chromatography. Results: Individual n-3 PUFA or AA had no effect on the mRNA expression of peroxisome-proliferator-activated receptor-γ; however, AA+EPA and AA+DPA significantly increased (P<0.05 the expression compared to control cells (38 and 42%, respectively. AA and AA+EPA increased the mRNA expression of acetyl-CoA carboxylase 1 (P<0.05. AA treatment decreased the mRNA expression of stearoyl-CoA desaturase (SCD1 (P<0.01, while n-3 PUFA, except EPA, had no effect compared to control cells. AA+DHA and AA+DPA inhibited SCD1 gene expression (P<0.05 suggesting a dominant effect of AA. Fatty acids analysis of adipocytes revealed a higher accretion of AA compared to n-3 PUFA. Conclusions: Our findings reveal that AA has a dominant effect on the regulation of lipogenic genes in adipocytes.

  2. Arachidonic acid triggers [Ca2+]i increases in rat round spermatids by a likely GPR activation, ERK signalling and ER/acidic compartments Ca2+ release

    Science.gov (United States)

    Paillamanque, Joaquin; Sanchez-Tusie, Ana; Carmona, Emerson M.; Treviño, Claudia L.; Sandoval, Carolina; Nualart, Francisco; Osses, Nelson

    2017-01-01

    Arachidonic acid (AA), a compound secreted by Sertoli cells (SC) in a FSH-dependent manner, is able to induce the release of Ca2+ from internal stores in round spermatids and pachytene spermatocytes. In this study, the possible site(s) of action of AA in round spermatids, the signalling pathways associated and the intracellular Ca2+ stores targeted by AA-induced signalling were pharmacologically characterized by measuring intracellular Ca2+ using fluorescent Ca2+ probes. Our results suggest that AA acts by interacting with a fatty acid G protein coupled receptor, initiating a G protein signalling cascade that may involve PLA2 and ERK activation, which in turn opens intracellular ryanodine-sensitive channels as well as NAADP-sensitive channels in acidic intracellular Ca2+ stores. The results presented here also suggest that AMPK and PKA modulate this AA-induced Ca2+ release from intracellular Ca2+ stores in round spermatids. We propose that unsaturated free fatty acid lipid signalling in the seminiferous tubule is a novel regulatory component of rat spermatogenesis. PMID:28192519

  3. Competitive Interaction Between Plasma Omega-3 Fatty Acids and Arachidonic Acid is Related to Down-Regulation of A Signaling Mediator.

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    Yui, Kunio; Imataka, George; Kawasaki, Yohei

    2016-01-01

    Autism spectrum disorders (ASD) may be attributed to altered composition of polyunsaturated fatty acids. We examined the relationships between the plasma ratios of docosahexaenoic acid (DHA)/arachidonic acid (AA) and eicosapentaenoic acid (EPA)/AA, and biomarkers of AA-related signaling mediators, i.e., ceruloplasmin, transferrin and superoxide dismutase, with the behavioral symptoms of 30 individuals with ASD (mean age, 13.0 years old) and 20 age- and gender-matched normal controls (mean age, 13.6 years old). Behavioral symptoms were assessed using the Aberrant Behavior Checklists (ABC). The ASD group had significantly higher plasma DHA/AA and EPA/AA ratios, as well as ABC scores, compared to the control group. The plasma ceruloplasmin levels in the ASD group were significantly reduced compared to those in the control group. Multiple linear regression demonstrated that plasma DHA/AA ratio was a fitting model for distinguishing the ASD group from the control group. These findings suggested that increased plasma DHA/AA ratio may be related to lower plasma levels of ceruloplasmin, which may contribute to the pathophysiology of behavioral symptoms in 30 individuals with ASD.

  4. Long-term modifications of blood pressure in normotensive and spontaneously hypertensive rats by gene delivery of rAAV-mediated cytochrome P450 arachidonic acid hydroxylase

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Arachidonic acid cytochrome P-450 (CYP) hydroxylase 4A isoforms, including 4A1, 4A2, 4A3 and 4A8 in the rat kidney, catalyze arachidonic acid to produce 19/20-Hydroxyeicosatetraenoic acids (20-HETE), a biologically active metabolite, which plays an important role in the regulation of blood pressure. However, controversial results have been reported regarding the exact role of 20-HETE on blood pressure. In the present study, we used recombinant adenoassociated viral vector (rAAV) to deliver CYP 4A1 cDNA and antisense 4A1 cDNA into Sprague-Dawley (SD) rats and spontaneously hypertensive rats (SHR), respectively, to investigate the effects of long-term modifications of blood pressure and the potential for gene therapy of hypertension. The mean systolic pressure increased by 14.2±2.5 mm Hg in rAAV.4A1-treated SD rats and decreased by 13.7±2.2 mm Hg in rAAV.anti4A1-treated SHR rats 5 weeks after the injection compared with controls and these changes in blood pressure were maintained until the experiments ended at 24weeks. In 4A1 treated animals CYP4A was overexpressed in various tissues, but preferentially in the kidney at both mRNA and protein levels. In anti-4A1-treated SHR, CYP4A mRNA in various tissues was probed, especially in kidneys,but 4A1 protein expression was almost completely inhibited. These results suggest that arachidonic acid CYP hydroxylases contribute not only to the maintenance of normal blood pressure but also to the development of hypertension.rAAV-mediated anti4A administration strategy has the potential to be used as targeted gene therapy in human hypertension by blocking expression of CYP 4A in kidneys.

  5. Interrelated effects of dihomo-γ-linolenic and arachidonic acids, and sesamin on hepatic fatty acid synthesis and oxidation in rats.

    Science.gov (United States)

    Ide, Takashi; Ono, Yoshiko; Kawashima, Hiroshi; Kiso, Yoshinobu

    2012-12-14

    Interrelated effects of dihomo-γ-linolenic acid (DGLA) and arachidonic acid (ARA), and sesamin, a sesame lignan, on hepatic fatty acid synthesis and oxidation were examined in rats. Rats were fed experimental diets supplemented with 0 or 2 g/kg sesamin (1:1 mixture of sesamin and episesamin), containing 100 g/kg of maize oil or fungal oil rich in DGLA or ARA for 16 d. Among the groups fed sesamin-free diets, oils rich in DGLA or ARA, especially the latter, compared with maize oil strongly reduced the activity and mRNA levels of various lipogenic enzymes. Sesamin, irrespective of the type of fat, reduced the parameters of lipogenic enzymes except for malic enzyme. The type of dietary fat was rather irrelevant in affecting hepatic fatty acid oxidation among rats fed the sesamin-free diets. Sesamin increased the activities of enzymes involved in fatty acid oxidation in all groups of rats given different fats. The extent of the increase depended on the dietary fat type, and the values became much higher with a diet containing sesamin and oil rich in ARA in combination than with a diet containing lignan and maize oil. Analyses of mRNA levels revealed that the combination of sesamin and oil rich in ARA compared with the combination of lignan and maize oil markedly increased the gene expression of various peroxisomal fatty acid oxidation enzymes but not mitochondrial enzymes. The enhancement of sesamin action on hepatic fatty acid oxidation was also confirmed with oil rich in DGLA but to a lesser extent.

  6. Effects of naturally occurring dihydroflavonols from Inula viscosa on inflammation and enzymes involved in the arachidonic acid metabolism.

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    Hernández, Victoriano; Recio, M Carmen; Máñez, Salvador; Giner, Rosa M; Ríos, José-Luis

    2007-07-19

    The anti-inflammatory properties of three flavanones isolated from Inula viscosa, sakuranetin, 7-O-methylaromadendrin, and 3-acetyl-7-O-methylaromadendrin, have been tested both in vitro and in vivo. Acute inflammation in vivo was induced by means of topical application of 12-O-tetradecanoylphorbol 13-acetate (TPA) to mouse ears or by subcutaneous injection of phospholipase A(2) (PLA(2)) into mouse paws. The test compounds were evaluated in vitro for their effect on both the metabolism of arachidonic acid and on the release and/or activity of enzymes involved in the inflammatory response such as elastase, myeloperoxidase (MPO), and protein kinase C (PKC). The most active compounds in vivo against PLA(2)-induced paw oedema were 7-O-methylaromadendrin (ED(50)=8 mg/kg) and sakuranetin (ED(50)=18 mg/kg). In contrast, the most potent compound against TPA-induced ear oedema was 3-acetyl-7-O-methylaromadendrin (ED(50)=185 microg/ear), followed by sakuranetin (ED(50)=205 microg/ear). In vitro, the latter compound was the most potent inhibitor of leukotriene (LT) B(4) production by peritoneal rat neutrophils (IC(50)=9 microM) and it was also the only compound that directly inhibited the activity of 5-lipoxygenase (5-LOX). 3-Acetyl-7-O-methylaromadendrin also inhibited LTB(4) production (IC(50)=15 microM), but had no effect on 5-LOX activity. The only flavanone that inhibited the secretory PLA(2) activity in vitro was 7-O-methylaromadendrin. This finding may partly explain the anti-inflammatory effect observed in vivo, although other mechanisms such as the inhibition of histamine release by mast cells may also be implicated. Sakuranetin at 100 microM was found to inhibit elastase release, although this result is partly due to direct inhibition of the enzyme itself. At the same concentration, 7-O-methylaromadendrin only affected the enzyme release. Finally, none of the flavanones exhibited any effect on MPO or PKC activities. Taken together, these findings indicate that

  7. An Optimized High Throughput Clean-Up Method Using Mixed-Mode SPE Plate for the Analysis of Free Arachidonic Acid in Plasma by LC-MS/MS.

    Science.gov (United States)

    Wang, Wan; Qin, Suzi; Li, Linsen; Chen, Xiaohua; Wang, Qunjie; Wei, Junfu

    2015-01-01

    A high throughput sample preparation method was developed utilizing mixed-mode solid phase extraction (SPE) in 96-well plate format for the determination of free arachidonic acid in plasma by LC-MS/MS. Plasma was mixed with 3% aqueous ammonia and loaded into each well of 96-well plate. After washing with water and methanol sequentially, 3% of formic acid in acetonitrile was used to elute arachidonic acid. The collected fraction was injected onto a reversed phase column at 30°C with mobile phase of acetonitrile/water (70 : 30, v/v) and detected by LC-MS/MS coupled with electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode. The calibration curve ranged from 10 to 2500 ng/mL with sufficient linearity (r (2) = 0.9999). The recoveries were in the range of 99.38% to 103.21% with RSD less than 6%. The limit of detection is 3 ng/mL.

  8. Differential effects of docoosahexaenoic and arachidonic acid on fatty acid composition and myosin heavy chain-related genes of slow- and fast-twitch skeletal muscle tissues.

    Science.gov (United States)

    Hashimoto, Michio; Inoue, Takayuki; Katakura, Masanori; Hossain, Shahdat; Mamun, Abdullah Al; Matsuzaki, Kentaro; Arai, Hiroyuki; Shido, Osamu

    2016-04-01

    Myosin heavy chain (MHC) mediates the metabolic and contractile responses of skeletal muscles. MHC displays different isoforms, each of which has different characteristics. To better understand the effect of polyunsaturated fatty acids in skeletal muscles, rats were fed with control-, docosahexaenoic acid (DHA)-, and arachidonic acid (ARA)-oil, and the effects on plasma and muscular fatty acid profile, oxidative stress, mRNA levels of myosin heavy chain isoforms MHC1 of slow-twitch muscle (SO) and MHC2A, MHC2X, and MHCB isoforms of extensor digitorum longus (EDL) of fast-twitch muscle were evaluated. Concomitantly, mRNA levels of anti-oxidative enzymes, such as, catalase, glutathione peroxidase (GPx) and superoxide dismutase (SOD were determined. The expressions of MHC1, MHC2A, MHC2X, and MHC2B were lower in the SO of the DHA-fed rats. In the EDL muscles of DHA-fed rats, the expressions of MHC1 and MHC2A increased; however, the expressions of MHC2X increased and that of the MHC2 were not altered. Oxidative stress, as indicated by the levels of LPO, was significantly higher in the plasma of the ARA-fed rats, when compared with that of the DHA-fed rats. The LPO levels were higher both in the SO and EDL muscles of ARA-fed rats. Compared with ARA oil intake, DHA oil showed higher mRNA levels of GPx and SOD. Catalase expression was higher only in the EDL but not in the SO-type muscles. Our studies finally indicate that DHA and ARA differentially affect the regulation of contractile and metabolic properties of slow- and fast-twitch skeletal muscles.

  9. A quantitiative LC-MS/MS method for the measurement of arachidonic acid, prostanoids, endocannabinoids, N-acylethanolamines and steroids in human plasma.

    Science.gov (United States)

    Gachet, María Salomé; Rhyn, Peter; Bosch, Oliver G; Quednow, Boris B; Gertsch, Jürg

    2015-01-22

    Free arachidonic acid is functionally interlinked with different lipid signaling networks including those involving prostanoid pathways, the endocannabinoid system, N-acylethanolamines, as well as steroids. A sensitive and specific LC-MS/MS method for the quantification of arachidonic acid, prostaglandin E2, thromboxane B2, anandamide, 2-arachidonoylglycerol, noladin ether, lineoyl ethanolamide, oleoyl ethanolamide, palmitoyl ethanolamide, steroyl ethanolamide, aldosterone, cortisol, dehydroepiandrosterone, progesterone, and testosterone in human plasma was developed and validated. Analytes were extracted using acetonitrile precipitation followed by solid phase extraction. Separations were performed by UFLC using a C18 column and analyzed on a triple quadrupole MS with electron spray ionization. Analytes were run first in negative mode and, subsequently, in positive mode in two independent LC-MS/MS runs. For each analyte, two MRM transitions were collected in order to confirm identity. All analytes showed good linearity over the investigated concentration range (r>0.98). Validated LLOQs ranged from 0.1 to 190ng/mL and LODs ranged from 0.04 to 12.3ng/mL. Our data show that this LC-MS/MS method is suitable for the quantification of a diverse set of bioactive lipids in plasma from human donors (n=32). The determined plasma levels are in agreement with the literature, thus providing a versatile method to explore pathophysiological processes in which changes of these lipids are implicated.

  10. Developmental Outcomes at 24 Months of Age in Toddlers Supplemented with Arachidonic Acid and Docosahexaenoic Acid: Results of a Double Blind Randomized, Controlled Trial

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    Angela M. Devlin

    2017-09-01

    Full Text Available Little is known about arachidonic acid (ARA and docosahexaenoic acid (DHA requirements in toddlers. A longitudinal, double blind, controlled trial in toddlers (n = 133 age 13.4 ± 0.9 months (mean ± standard deviation, randomized to receive a DHA (200 mg/day and ARA (200 mg/day supplement (supplement or a corn oil supplement (control until age 24 months determined effects on neurodevelopment. We found no effect of the supplement on the Bayley Scales of Infant and Toddler Development 3rd Edition (Bayley-III cognitive and language composites and Beery–Buktenica Developmental Test of Visual–Motor Integration (Beery VMI at age 24 months. Supplemented toddlers had higher RBC phosphatidylcholine (PC, phosphatidylethanolamine (PE, and plasma DHA and ARA compared to placebo toddlers at age 24 months. A positive relationship between RBC PE ARA and Bayley III Cognitive composite (4.55 (0.21–9.00, B (95% CI, p = 0.045 in supplemented boys, but not in control boys, was observed in models adjusted for baseline fatty acid, maternal non-verbal intelligence, and BMI z-score at age 24 months. A similar positive relationship between RBC PE ARA and Bayley III Language composite was observed for supplemented boys (11.52 (5.10–17.94, p < 0.001 and girls (11.19 (4.69–17.68, p = 0.001. These findings suggest that increasing the ARA status in toddlers is associated with better neurodevelopment at age 24 months.

  11. The effect of trinitrobenzene sulfonic acid on gut-derived smooth muscle cell arachidonic acid metabolism: role of endogenous prostanoids

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    W. E. Longo

    1997-01-01

    Full Text Available The contribution of smooth muscle cells as a potential source of eicosanoid production during inflammatory states remains to be elucidated. We investigated the effect of trinitrobenzene sulfonic acid (TNB, a known pro-inflammatory agent, on jejunal smooth muscle cell eicosanoid production. Human gut-derived smooth muscle cells (HISM were incubated with TNB for 1 hour. Additionally, some cells were preincubated with either dimethylthiourea, or indomethacin for 1 hour before exposure to identical concentrations of TNB. Incubation with TNB led to significant increases in PGE2 and 6-keto PGF-1α release, but not leukotriene B4 release; responses which were both inhibited by dimethylthiourea and indomethacin treatment. Our results suggest that gutderived smooth muscle cells may represent an important source of proinflammatory prostanoids but not leukotrienes during inflammatory states of the intestine. The inhibition of prostanoid activity by thiourea may be mediated by suppression of cyclooxygenase activity in this cell line.

  12. The effect of non-steroidal anti-inflammatory drugs on the metabolism of /sup 14/C-arachidonic acid by human gingival tissue in vitro

    Energy Technology Data Exchange (ETDEWEB)

    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 /sup 14/C-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.

  13. Arachidonate metabolism in bovine gallbladder muscle

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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

  15. Influencia del [alpha]-tocoferol en la incorporacion y peroxidacion del acido araquidonico en alevines parr de salmon del Atlantico (Salmo salar L.)/Influence of [alpha]-tocopherol on arachidonic acid deposition and peroxidation in Atlantic salmon (Salmo salar L.) fingerlings

    National Research Council Canada - National Science Library

    Patricio Dantagnan; Astrid Domínguez; Aliro Bórquez; Javier Alcaíno; Claudio Pavez; Adrián Hernández

    2012-01-01

      The synergistic effect of arachidonic acid (ARA) (20:4n-6) and a-tocopherol on the accumulation of fatty acids and the peroxidation of lipids in liver and muscle was evaluated in Atlantic salmon (Salmo salar) juveniles...

  16. Isoliquiritigenin induces growth inhibition and apoptosis through downregulating arachidonic acid metabolic network and the deactivation of PI3K/Akt in human breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ying; Zhao, Haixia [Department of Pharmacology, School of Medicine, Wuhan University, Wuhan 430071 (China); Wang, Yuzhong [Key Laboratory for Oral Biomedical Engineering of Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan 430079 (China); Zheng, Hao; Yu, Wei; Chai, Hongyan [Department of Pharmacology, School of Medicine, Wuhan University, Wuhan 430071 (China); Zhang, Jing [Animal Experimental Center of Wuhan University, Wuhan 430071 (China); Falck, John R. [Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390,USA (United States); Guo, Austin M. [Department of Pharmacology, School of Medicine, Wuhan University, Wuhan 430071 (China); Department of Pharmacology, New York Medical College, Valhalla, NY 10595 (United States); Yue, Jiang; Peng, Renxiu [Department of Pharmacology, School of Medicine, Wuhan University, Wuhan 430071 (China); Yang, Jing, E-mail: yangjingliu2013@163.com [Department of Pharmacology, School of Medicine, Wuhan University, Wuhan 430071 (China); Research Center of Food and Drug Evaluation, Wuhan University, Wuhan 430071 (China)

    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

  17. Targeted profiling of arachidonic acid and eicosanoids in rat tissue by UFLC-MS/MS: Application to identify potential markers for rheumatoid arthritis.

    Science.gov (United States)

    Wang, Nannan; Zhao, Xiaoning; Wang, Weihui; Peng, Yan; Bi, Kaishun; Dai, Ronghua

    2017-01-01

    We describe a method for the targeted analysis of bioactive arachidonic acid metabolites through cyclooxygenase (COX) and lipoxygenase (LOX) pathway in knee joint, liver, kidney, spleen and heart using an ultra-fast liquid chromatography-tandem mass (UFLC-MS/MS) method. Method validation was investigated, including linearity, precision, accuracy, matrix effect, extraction recovery and stability for the simultaneous analysis of prostaglandins (PGs), thromboxanes (TXs), leukotrienes (LTs) and hydroxyeicosatetraenoic acids (HETEs). The method enables us to chromatographically separate branched-chain species from their straight-chain isomers as well as separate biologically important eicosanoids. The concentrations of the following major eicosanoids were significantly increased in rheumatoid arthritis model rats than in normal ones: 5-HETE, 8-HETE, 12-HETE, 15-HETE, PGF2α, TXB2, 5-HpETE, LTE4, PGE2, PGD2, LTB4. Further multivariate data analysis (partial least square-discriminant analysis) showed COX products (PGs, TXs) were readily distributed towards liver and kidney, LOX products (LTs, HETEs) towards knee joint and spleen, and heart had no characteristic metabolites. The method described here offers a useful tool for the evaluation of complex regulatory eicosanoids responses in RA disease states and provides support for use of dual inhibitors of COX and LOX enzymes on RA treatment.

  18. Analysis of cytochrome P450 metabolites of arachidonic acid by stable isotope probe labeling coupled with ultra high-performance liquid chromatography/mass spectrometry.

    Science.gov (United States)

    Zhu, Quan-Fei; Hao, Yan-Hong; Liu, Ming-Zhou; Yue, Jiang; Ni, Jian; Yuan, Bi-Feng; Feng, Yu-Qi

    2015-09-04

    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

  19. Developmental docosahexaenoic and arachidonic acid supplementation improves adult learning and increases resistance against excitotoxicity in the brain

    NARCIS (Netherlands)

    Gódor-Kacsándi, A.; Felszeghy, K.; Ranky, M.; Luiten, P.G.M.; Nyakas, C.

    2013-01-01

    Through metabolic imprinting mechanisms a number of bioactive molecules including polyunsaturated fatty acids affect brain functions in the developmental age and longer-lasting beneficial effects are expected. In this study pregnant rats were offered diets either containing no docosahexaenoic acid (

  20. Identification of a cyclooxygenase gene from the red alga Gracilaria vermiculophylla and bioconversion of arachidonic acid to PGF(2α) in engineered Escherichia coli.

    Science.gov (United States)

    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.

  1. The role of the arachidonic acid cascade in the species-specific X-ray-induced inflammation of the rabbit eye

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Arachidonic acid alters tomato HMG expression and fruit growth and induces 3-hydroxy-3-methylglutaryl coenzyme A reductase-independent lycopene accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Concepcion, M.; Gruissem, W. [Univ. of California, Berkeley, CA (United States). Dept. of Plant and Microbial Biology

    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.

  3. Comparison of the effect of timegadine, levamisole, and D-penicillamine on human neutrophil metabolism of endogenous arachidonic acid and chemotaxis

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, O.H.; Ahnfelt-Roenne, I. Department of Pharmacology, Leo Pharmaceutical Products, Ballerup; Elmgreen, J.

    1988-01-01

    The effect of timegadine, a novel experimental antirheumatic drug, on human neutrophil (PMN) 5-lipoxygenase activity and leukotriene B/sub 4/ (LTB/sub 4/) chemotaxis was compared with that of two second-line antiinflammatory drugs, D-penicillamine and levamisole. 1-/sup 14/C-Arachidonic acid (AA) was incorporated into the purified cells until steady state conditions were obtained. After preincubation with serial dilutions of the three drugs, AA release and metabolism was stimulated with calcium ionophore A23187. The radioactive eicosanoids released were extracted and separated by thinlayer chromatography, followed by autoradiography and quantitative laser densitometry. Chemotaxi of PMNs towards LTB/sub 4/ was measured in a modified Boyden chamber. Timegardine showed dose-dependent inhibition of both the 5-lipoxygenase pathway (IC50 3.4 x 10/sup -5/ M), and of chemotaxis (IC50 3 x 10/sup -4/ M). Inhibition of the release of AA from phospholipids, however, occurred only at therapeutically irrelevant doses (millimolar concentrations). Levamisole and D-penicillamine did not inhibit any of the cell functions investigated. Inhibition of both neutrophil motility and cellular synthesis of pro-inflammatory eicosanoids, may thus contribute to the clinical effects of timegadine in rheumatoid arthritis.

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

    Science.gov (United States)

    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.

  5. Chronic dietary n-6 PUFA deprivation leads to conservation of arachidonic acid and more rapid loss of DHA in rat brain phospholipids.

    Science.gov (United States)

    Lin, Lauren E; Chen, Chuck T; Hildebrand, Kayla D; Liu, Zhen; Hopperton, Kathryn E; Bazinet, Richard P

    2015-02-01

    To determine how the level of dietary n-6 PUFA affects the rate of loss of arachidonic acid (ARA) and DHA in brain phospholipids, male rats were fed either a deprived or adequate n-6 PUFA diet for 15 weeks postweaning, and then subjected to an intracerebroventricular infusion of (3)H-ARA or (3)H-DHA. Brains were collected at fixed times over 128 days to determine half-lives and the rates of loss from brain phospholipids (J out). Compared with the adequate n-6 PUFA rats, the deprived n-6-PUFA rats had a 15% lower concentration of ARA and an 18% higher concentration of DHA in their brain total phospholipids. Loss half-lives of ARA in brain total phospholipids and fractions (except phosphatidylserine) were longer in the deprived n-6 PUFA rats, whereas the J out was decreased. In the deprived versus adequate n-6 PUFA rats, the J out of DHA was higher. In conclusion, chronic n-6 PUFA deprivation decreases the rate of loss of ARA and increases the rate of loss of DHA in brain phospholipids. Thus, a low n-6 PUFA diet can be used to target brain ARA and DHA metabolism.

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

    Science.gov (United States)

    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.

  7. Nrf2 is crucial for the down-regulation of Cyp7a1 induced by arachidonic acid in Hepg2 cells.

    Science.gov (United States)

    Zhang, Jin-Ming; Wang, Xing-He; Hao, Li-Hong; Wang, He; Zhang, Xiu-Ying; Muhammad, Ishfaq; Qi, Yue; Li, Guang-Liang; Sun, Xiao-Qi

    2017-03-07

    In former research, cyp7a1 expression was decreased but Nrf2 transcription and hepatic arachidonic acid (AA) concentration were increased in high-fat diet fed mice. This study aims to investigate the influence of AA in CYP7A1 expression and the role of Nrf2 in regulating CYP7A1 in the process. HepG2 cells were administered with different concentrations of AA. Nrf2 and CYP7A1 expressions were analyzed by real-time PCR and western blot. Nrf2 silenced and over-expressed cell models were constructed by Nrf2 siRNA and eukaryotic expression vector transient transfections and were used to investigate the role of Nrf2 in regulating CYP7A1 following AA administration. The results showed that Nrf2 was increased dose-dependently but CYP7A1 was decreased dose-dependently in cells treated with increasing concentrations of AA. The expression of CYP7A1 was increased by Nrf2 silence and was decreased by Nrf2 over-expression in HepG2 cells treated with different concentrations of AA. In conclusion, Nrf2 plays a significant role in the down-regulation of CYP7A1 induced by AA in HepG2 cells.

  8. Determination of arachidonic acid by on-line solid-phase extraction HPLC with UV detection for screening of cytosolic phospholipase A2α inhibitors.

    Science.gov (United States)

    Hanekamp, Walburga; Lehr, Matthias

    2012-07-01

    An on-line solid-phase extraction (SPE)-liquid chromatographic method with ultraviolet detection at 200nm for screening of inhibitors of cytosolic phospholipase A(2)α (cPLA(2)α) was developed and validated. cPLA(2)α was isolated from porcine platelets. Enzyme activity was determined by measuring the release of arachidonic acid from a phospholipid substrate using automated on-line sample clean up on a trap column followed by isocratic back-flush elution on a RP18 analytical column. While the use of a conventional RP18 column for trapping the analyte led to peak broadening only after a few runs due to pollution of the column by binding of components present in the enzyme preparation, the application of a turbulent flow column (TurboFlow Cyclone™) resulted in sharp peaks even after a plurality of injections. Interestingly, for sample introduction a turbulent flow of the mobile phase produced by high flow rates was not necessary to maintain good peak shapes. The same result could also be achieved applying low flow rates (0.5 mL/min). Several known cPLA(2)α inhibitors were used to validate the test system.

  9. Arachidonic acid affects biofilm formation and PGE2 level in Candida albicans and non-albicans species in presence of subinhibitory concentration of fluconazole and terbinafine.

    Science.gov (United States)

    Mishra, Nripendra Nath; Ali, Shakir; Shukla, Praveen K

    2014-01-01

    Candida albicans utilizes arachidonic acid (AA) released during the course of infection (Candidiasis) from phospholipids of infected host cell membranes and synthesizes extracellular prostaglandin(s) which play an important role in hyphae formation and host cell damage. C. albicans biofilms secrete significantly more prostaglandin(s) and evidence suggests that Candida biofilms have dramatically reduced susceptibility to majority of antifungal drugs. AA influences the saturation level of lipids and fluidity of yeast cell membranes. Therefore the aim of this study was to evaluate the effect of AA alone or in combination with antifungal agents on biofilm formation and production of prostaglandin (PGE2) in C. albicans, C. parapsilosis, C. glabrata, C. tropicalis, and C. albicans amphotericin B resistant strain (AmBR). Maximum biofilm formation was found to be in the case of C. albicans compared to C. non-albicans species. However, among the non-albicans species C. tropicalis exhibited highest biofilm formation. Treatment with AA in combination with subinhibitory concentrations of fluconazole and terbinafine separately exhibited significant (p<0.05) reduction in biofilm formation against C. glabrata, C. parapsilosis, C. tropicalis and AmBR as compared to their individual effect. Further, these two antifungal agents in combination with AA caused an increase in production of prostaglandin from fungal cell itself which was significant (p<0.05) in case of all the strains tested.

  10. Dose-dependent changes in neuroinflammatory and arachidonic acid cascade markers with synaptic marker loss in rat lipopolysaccharide infusion model of neuroinflammation

    Directory of Open Access Journals (Sweden)

    Kellom Matthew

    2012-05-01

    Full Text Available Abstract Background Neuroinflammation, caused by six days of intracerebroventricular infusion of bacterial lipopolysaccharide (LPS, stimulates rat brain arachidonic acid (AA metabolism. The molecular changes associated with increased AA metabolism are not clear. We examined effects of a six-day infusion of a low-dose (0.5 ng/h and a high-dose (250 ng/h of LPS on neuroinflammatory, AA cascade, and pre- and post-synaptic markers in rat brain. We used artificial cerebrospinal fluid-infused brains as controls. Results Infusion of low- or high-dose LPS increased brain protein levels of TNFα, and iNOS, without significantly changing GFAP. High-dose LPS infusion upregulated brain protein and mRNA levels of AA cascade markers (cytosolic cPLA2-IVA, secretory sPLA2-V, cyclooxygenase-2 and 5-lipoxygenase, and of transcription factor NF-κB p50 DNA binding activity. Both LPS doses increased cPLA2 and p38 mitogen-activated protein kinase levels, while reducing protein levels of the pre-synaptic marker, synaptophysin. Post-synaptic markers drebrin and PSD95 protein levels were decreased with high- but not low-dose LPS. Conclusions Chronic LPS infusion has differential effects, depending on dose, on inflammatory, AA and synaptic markers in rat brain. Neuroinflammation associated with upregulated brain AA metabolism can lead to synaptic dysfunction.

  11. 内皮源性缩血管因子花生四烯酸代谢物的作用多样性%Diversity of endothelium-derived vasocontracting factors--arachidonic acid metabolites

    Institute of Scientific and Technical Information of China (English)

    KURAHASHI Kazuyoshi; NISHIHASHI Tsuyoshi; TRANDAFIR Cristina Corina; WANG Ai-Min; MURAKAMI Shizuka; JI Xu

    2003-01-01

    Vascular endothelium releases vasocontracting and/or vasorelaxing substances. Here, we report the diversity of endothelium-derived vasocontracting factors (EDCFs), arachidonic acid metabolites, and discuss the pathophysiological significance. In the canine basilar artery and the rabbit intrapulmonary artery, acetylcholine-induced contractions (Ach-induced EDC) are due to endothelial thromboxane A2 (TXA2) (TXA2-type). The Ach-induced EDC in the rabbit coronary artery is due to endothelial leukotrienes (LTs) (LTs-type). In addition, in the rat coronary artery, nicotine and noradrenaline (Nad)-induced EDCs are due to endothelial COX-metabolites (COX metabolite-type). These arachidonic acid metabolites derived from endothelium (activation by vasoactive substances including Ach, Nad and nicotine) cause a contraction of vascular smooth muscle cells and may disturb the local circulation. These EDCFs (TXA2, LTs and COX-metabolites) may be involved in the pathophysiology of cardiovascular immuno-inflammatory diseases.

  12. AD6 (8-monochloro-3-beta-diethylamino-ethyl-4-methyl-7-ethoxycarbonyl-meth oxy coumarin) inhibits the release of arachidonic acid in human platelets stimulated by thrombin

    Energy Technology Data Exchange (ETDEWEB)

    Porcellati, S.; Costantini, V.; Prosdocimi, M.; Pistolesi, R.; Porrovecchio, P.; Nenci, G.G.; Goracci, G.

    1987-07-01

    The coumarin derivative AD6 is known to inhibit platelet aggregation and release and it possesses vasodilatory properties on coronary arteries of laboratory animals. Furthermore, the inhibition of the production of TxB2 from endogenous substrates after stimulation of human platelets with collagen has been demonstrated. The present report demonstrates that AD6 inhibits the production of labeled arachidonic acid and diglycerides from phospholipids of platelets stimulated with thrombin. This effect is dose-dependent and is already evident at a concentration of the drug (25 microM) which is unable to prevent the aggregation. Apparently, AD6 inhibits the release of arachidonic acid from phosphatidylinositol and choline phosphoglycerides which are the main sources of the substrate for the synthesis of prostaglandins and thromboxanes.

  13. Identification and absolute configuration of dihydroxy-arachidonic acids formed by oxygenation of 5S-HETE by native and aspirin-acetylated COX-2

    Science.gov (United States)

    Mulugeta, Surafel; Suzuki, Takashi; Hernandez, Noemi Tejera; Griesser, Markus; Boeglin, William E.; Schneider, Claus

    2010-01-01

    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. PMID:19752399

  14. Inhibition of protein kinase B by Palmitate in the insulin signaling of HepG2 cells and the preventive effect of Arachidonic acid on insulin resistance

    Institute of Scientific and Technical Information of China (English)

    XIA Yanzhi; WAN Xuedong; DUAN Qiuhong; HE Shansu; WANG Ximing

    2007-01-01

    Elevated plasma levels of free fatty acids(FFAs)may contribute to insulin resistance (IR)that is characteristic of type 2 diabetes mellitus.In this study,we investigated the effects of two fatty acids,palmitate(PA)and arachidonic acid (AA)on glycogenesis under insulin signaling in HepG2cells,a transformed hepatic carcinoma cell line.In the presence of 200 μmol of palmitate,insulin(10-7 mol/L)stimulation of glycogenesis was inhibited,as evidenced by increased glucose in the medium and decreased intracellular glycogen.Wortmannin(WM),a specific inhibitor of PI3K,dramatically decreased the amount of intracellular glycogen in cells without PA incubation.However,glycogen in PA treated cells was not significantly changed by WM,indicating that PA may also act on PI3K.Interestingly,AA restored the effects of WM inhibition on glycogenesis in PA cells.Western blot analysis demonstrated that PA in the absence of WM increased phosphorylated glycogen synthase(inactive form of GS)and decreased phosphorylated protein kinase B(active form of PKB),causing a reduction of intracellular glycogen.AA,however,reversed the effects of PA on GS and PKB.Furthermore,inhibition of protein kinase C(PKC)by a specific inhibitor chelerythrine chloride (CC)abolished the inhibitory efrect of PA on glycogen synthesis by decreasing phosphorylated GS and increasing phosphorylated PKB.However,the effect of CC in the presence of PA disappeared when AA was also present.Our results suggest that there is a disruption of the insulin signaling pathway between PKB and GS when the cells were exposed to PA,contributing to IR.PA may also interrupt the PKC signaling pathway.In contrast,AA could rescue glycogenesis impaired by PA.

  15. Consumption of Red Meat, but Not Cooking Oils High in Polyunsaturated Fat, Is Associated with Higher Arachidonic Acid Status in Singapore Chinese Adults

    Directory of Open Access Journals (Sweden)

    Jowy Yi Hoong Seah

    2017-01-01

    Full Text Available High arachidonic acid (AA; 20:4 n − 6 status may have adverse effects on inflammation and risk of cardiovascular diseases. Concerns about high intake of n − 6 polyunsaturated fatty acids (PUFAs are based on the premise that endogenous conversion from linoleic acid (LA; 18:2 n − 6 is an important source of AA, but few population-based studies have investigated dietary determinants of AA status. In this study, we examined habitual food consumption in relation to plasma concentrations of AA and other PUFAs in population-based studies. We used cross-sectional data from 269 healthy, ethnic Chinese participants (25–80 years old with contrasting intakes of fish and red meat from the Singapore Prospective Study Program and 769 healthy participants (44–74 years old from the Singapore Chinese Health Study as a validation set. Multivariable linear regression was used to examine PUFA intake (% energy and food sources of PUFA (fish, red meat, poultry, soy and cooking oils in relation to plasma PUFAs (AA, LA, dihomo-gamma-linolenic acid (DGLA; 20:3 n − 6, alpha-linolenic acid (ALA; 18:3 n − 3, eicosapentaenoic acid (EPA; 20:5 n − 3, and docosahexaenoic acid (DHA; 22:6 n − 3 concentrations. Higher intake of red meat was associated with higher plasma AA concentrations. High intake of PUFA or PUFA-rich oils was associated with higher plasma ALA but not with plasma AA. Higher intakes of soy were associated with higher ALA and fish with higher DHA and EPA concentrations. These associations were statistically significant (p < 0.05 in both studies. Red meat consumption, but not PUFA or PUFA-rich cooking oil, was associated with circulating AA suggesting that intake of pre-formed AA rather than LA is an important determinant of AA status. A diet high in fish, soy products and polyunsaturated cooking oil, and low in red meat may be associated with an optimal plasma profile of PUFA in this Chinese population.

  16. Consumption of Red Meat, but Not Cooking Oils High in Polyunsaturated Fat, Is Associated with Higher Arachidonic Acid Status in Singapore Chinese Adults

    Science.gov (United States)

    Seah, Jowy Yi Hoong; Gay, Gibson Ming Wei; Su, Jin; Tai, E-Shyong; Yuan, Jian-Min; Koh, Woon-Puay; Ong, Choon Nam; van Dam, Rob M.

    2017-01-01

    High arachidonic acid (AA; 20:4n-6) status may have adverse effects on inflammation and risk of cardiovascular diseases. Concerns about high intake of n-6 polyunsaturated fatty acids (PUFAs) are based on the premise that endogenous conversion from linoleic acid (LA; 18:2n-6) is an important source of AA, but few population-based studies have investigated dietary determinants of AA status. In this study, we examined habitual food consumption in relation to plasma concentrations of AA and other PUFAs in population-based studies. We used cross-sectional data from 269 healthy, ethnic Chinese participants (25–80 years old) with contrasting intakes of fish and red meat from the Singapore Prospective Study Program and 769 healthy participants (44–74 years old) from the Singapore Chinese Health Study as a validation set. Multivariable linear regression was used to examine PUFA intake (% energy) and food sources of PUFA (fish, red meat, poultry, soy and cooking oils) in relation to plasma PUFAs (AA, LA, dihomo-gamma-linolenic acid (DGLA; 20:3n-6), alpha-linolenic acid (ALA; 18:3n-3), eicosapentaenoic acid (EPA; 20:5n-3), and docosahexaenoic acid (DHA; 22:6n-3)) concentrations. Higher intake of red meat was associated with higher plasma AA concentrations. High intake of PUFA or PUFA-rich oils was associated with higher plasma ALA but not with plasma AA. Higher intakes of soy were associated with higher ALA and fish with higher DHA and EPA concentrations. These associations were statistically significant (p < 0.05) in both studies. Red meat consumption, but not PUFA or PUFA-rich cooking oil, was associated with circulating AA suggesting that intake of pre-formed AA rather than LA is an important determinant of AA status. A diet high in fish, soy products and polyunsaturated cooking oil, and low in red meat may be associated with an optimal plasma profile of PUFA in this Chinese population. PMID:28146136

  17. Arachidonic acid metabolism in TNS-induced chronic and immunologic enteritis in rats, and the effect of 5-ASA

    NARCIS (Netherlands)

    F.J. Zijlstra (Freek); A.P.J. van Dijk (Arie); N. Selve (N.); J.H.P. Wilson (Paul)

    1993-01-01

    textabstractInflammation of the rat distal intestine was induced by intradermal sensitization and subsequent multiple intrajejunal challenge with the hapten 2,4,6-trinitrobenzenesulphonic acid (TNBS) via an implanted catheter. The time course of the inflammatory reaction was followed by determinatio

  18. Arachidonic acid and lipoxin A4 attenuate alloxan-induced cytotoxicity to RIN5F cells in vitro and type 1 diabetes mellitus in vivo.

    Science.gov (United States)

    Gundala, Naveen K V; Naidu, Vegi G M; Das, Undurti N

    2017-03-01

    We studied whether polyunsaturated fatty acids (PUFAs) can protect rat insulinoma (RIN5F) cells against alloxan-induced apoptosis in vitro and type 1 diabetes mellitus (type 1 DM) in vivo and if so, mechanism of this beneficial action. In vitro study was conducted using RIN5F cells while in vivo study was performed in Wistar rats. The effect of PUFAs, cyclo-oxygenase and lipoxygenase inhibitors, various eicosanoids and PUFAs metabolites: lipoxin A4 (LXA4), resolvin D2 and protectin against alloxan-induced cytotoxicity to RIN5F cells and type 1 DM was studied. Expression of PDX1, P65 NF-kB and IKB in RIN5F cells and Nrf2, GLUT2, COX2, iNOS protein levels in the pancreatic tissue and plasma glucose, insulin and tumor necrosis factor-α and antioxidants, lipid peroxides and nitric oxide were measured. Of all, arachidonic acid (AA) was found to be the most effective against alloxan-induced cytotoxicity to RIN5F cells and preventing type 1 DM. Both cyclo-oxygenase and lipoxygenase inhibitors did not block the beneficial actions of AA in vitro and in vivo. Alloxan inhibited LXA4 production by RIN5F cells and in alloxan-induced type 1 DM Wistar rats. AA-treatment restored LXA4 levels to normal both in vitro and in vivo. LXA4 protected RIN5F cells against alloxan-induced cytotoxicity and prevented type 1 DM and restored expression of Nrf2, Glut2, COX2, and iNOS genes and abnormal antioxidants to near normal. AA seems to bring about its beneficial actions against alloxan-induced cytotoxicity and type 1 DM by enhancing the production of LXA4. © 2016 BioFactors, 43(2):251-271, 2017. © 2016 International Union of Biochemistry and Molecular Biology.

  19. The role of arachidonic acid/cyclooxygenase cascade, phosphodiesterase IV and Rho-kinase in H2S-induced relaxation in the mouse corpus cavernosum.

    Science.gov (United States)

    Aydinoglu, Fatma; Ogulener, Nuran

    2017-08-01

    Penile corpus cavernosum is an extremely vascularized tissue and cavernosal smooth muscle tone is regulated by the balance between contractile and relaxant factor. We investigated the possible role of arachidonic acid/cyclooxygenase cascade, phosphodiesterase IV (PDEIV) and Rho-kinase in exogenous hydrogen sulfide (H2S)-induced relaxation in mouse corpus cavernosum. The relaxant response to H2S (NaHS as exogenous H2S; 1-1000μM) were obtained in isolated mouse corpus cavernosum tissues which pre-contracted by phenylephrine (5μM). The effects of 4-(4-octadecylphenyl)-4-oxobutenoic acid (OBAA; 10μM), a selective phospholipase A2 (PLA2) inhibitor, indomethacin (1μM), a non-selective cyclooxygenase (COX) inhibitor, baicalein (10μM), a lipoxygenase (LOX) inhibitor, and proadifen (10μM), cytochrome P450 inhibitor, on the relaxant responses to H2S were investigated. Furthermore, the effects of theophylline (500μM) and rolipram (1μM), a non-selective and selective PDEIV inhibitor, and fasudil (3μM), a specific Rho-kinase inhibitor, were studied on H2S-induced relaxation. H2S-induced relaxations were significantly reduced by OBAA, indomethacin and proadifen but not baicalein. Furthermore, theophylline, rolipram and fasudil reduced H2S-induced relaxations. These results suggest that PLA2, COX, cytochrome P450, PDEIV and Rho-kinase pathway may involve in H2S-induced relaxation in mouse corpus cavernosum tissues. Copyright © 2017 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  20. Arachidonic acid enhances TPA-induced differentiation in human leukemia HL-60 cells via reactive oxygen species-dependent ERK activation.

    Science.gov (United States)

    Chien, Chih-Chiang; Wu, Ming-Shun; Shen, Shing-Chuan; Yang, Liang-Yo; Wu, Wen-Shin; Chen, Yen-Chou

    2013-04-01

    The phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), is a potent stimulator of differentiation in human leukemia cells; however, the effects of arachidonic acid (AA) on TPA-induced differentiation are still unclear. In the present study, we investigated the contribution of AA to TPA-induced differentiation of human leukemia HL-60 cells. We found that treatment of HL-60 cells with TPA resulted in increases in cell attachment and nitroblue tetrazolium (NBT)-positive cells, which were significantly enhanced by the addition of AA. Stimulation of TPA-induced intracellular reactive oxygen species (ROS) production by AA was detected in HL-60 cells via a DCHF-DA analysis, and the addition of the antioxidant, N-acetyl-cysteine (NAC), was able to reduce TPA+AA-induced differentiation in accordance with suppression of intracellular peroxide elevation by TPA+AA. Furthermore, activation of extracellular-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) by TPA+AA was identified in HL-60 cells, and the ERK inhibitor, PD98059, but not the JNK inhibitor, SP600125, inhibited TPA+AA-induced NBT-positive cells. Suppression of TPA+AA-induced ERK protein phosphorylation by PD98059 and NAC was detected, and AA enhanced ERK protein phosphorylation by TPA was in HL-60 cells. AA clearly increased TPA-induced HL-60 cell differentiation, as evidenced by a marked increase in CD11b expression, which was inhibited by NAC and PD98059 addition. Eicosapentaenoic acid (EPA) as well as AA showed increased intracellular peroxide production and differentiation of HL-60 cells elicited by TPA. Evidence of AA potentiation of differentiation by TPA in human leukemia cells HL-60 via activation of ROS-dependent ERK protein phosphorylation was first demonstrated herein.

  1. Inhibitors of the arachidonic acid pathway and peroxisome proliferator-activated receptor ligands have superadditive effects on lung cancer growth inhibition.

    Science.gov (United States)

    Avis, Ingalill; Martínez, Alfredo; Tauler, Jordi; Zudaire, Enrique; Mayburd, Anatoly; Abu-Ghazaleh, Raed; Ondrey, Frank; Mulshine, James L

    2005-05-15

    Arachidonic acid (AA) metabolizing enzymes and peroxisome proliferator-activated receptors (PPARs) have been shown to regulate the growth of epithelial cells. We have previously reported that exposure to the 5-lipoxygenase activating protein-directed inhibitor MK886 but not the cyclooxygenase inhibitor, indomethacin, reduced growth, increased apoptosis, and up-regulated PPARalpha and gamma expression in breast cancer cell lines. In the present study, we explore approaches to maximizing the proapoptotic effects of PPARgamma on lung cancer cell lines. Non-small-cell cancer cell line A549 revealed dose-dependent PPARgamma reporter activity after treatment with MK886. The addition of indomethacin in combination with MK886 further increases reporter activity. We also show increased growth inhibition and up-regulation of apoptosis after exposure to MK886 alone, or in combination with indomethacin and the PPAR ligand, 15-deoxy-Delta12,14-prostaglandin J2 compared with single drug exposures on the adenocarcinoma cell line A549 and small-cell cancer cell lines H345, N417, and H510. Real-time PCR analyses showed increased PPAR mRNA and retinoid X receptor (RXR)alpha mRNA expression after exposure to MK886 and indomethacin in a time-dependent fashion. The results suggest that the principal proapoptotic effect of these drugs may be mediated through the known antiproliferative effects of the PPARgamma-RXR interaction. We therefore explored a three-drug approach to attempt to maximize this effect. The combination of low-dose MK886, ciglitazone, and 13-cis-retinoic acid interacted at least in a superadditive fashion to inhibit the growth of lung cancer cell lines A549 and H1299, suggesting that targeting PPARgamma and AA action is a promising approach to lung cancer growth with a favorable therapeutic index.

  2. Antagonizing arachidonic acid-derived eicosanoids reduces inflammatory Th17 and Th1 cell-mediated inflammation and colitis severity.

    Science.gov (United States)

    Monk, Jennifer M; Turk, Harmony F; Fan, Yang-Yi; Callaway, Evelyn; Weeks, Brad; Yang, Peiying; McMurray, David N; Chapkin, Robert S

    2014-01-01

    During colitis, activation of two inflammatory T cell subsets, Th17 and Th1 cells, promotes ongoing intestinal inflammatory responses. n-6 polyunsaturated fatty acid- (PUFA-) derived eicosanoids, such as prostaglandin E2 (PGE2), promote Th17 cell-mediated inflammation, while n-3 PUFA antagonize both Th17 and Th1 cells and suppress PGE2 levels. We utilized two genetic mouse models, which differentially antagonize PGE2 levels, to examine the effect on Th17 cells and disease outcomes in trinitrobenzene sulfonic acid- (TNBS-) induced colitis. Fat-1 mice contain the ω3 desaturase gene from C. elegans and synthesize n-3 PUFA de novo, thereby reducing the biosynthesis of n-6 PUFA-derived eicosanoids. In contrast, Fads1 Null mice contain a disrupted Δ5 desaturase gene and produce lower levels of n-6 PUFA-derived eicosanoids. Compared to Wt littermates, Fat-1 and Fads1 Null mice exhibited a similar colitic phenotype characterized by reduced colonic mucosal inflammatory eicosanoid levels and mRNA expression of Th17 cell markers (IL-17A, RORγτ, and IL-23), decreased percentages of Th17 cells and, improved colon injury scores (P ≤ 0.05). Thus, during colitis, similar outcomes were obtained in two genetically distinct models, both of which antagonize PGE2 levels via different mechanisms. Our data highlight the critical impact of n-6 PUFA-derived eicosanoids in the promotion of Th17 cell-mediated colonic inflammation.

  3. Antagonizing Arachidonic Acid-Derived Eicosanoids Reduces Inflammatory Th17 and Th1 Cell-Mediated Inflammation and Colitis Severity

    Directory of Open Access Journals (Sweden)

    Jennifer M. Monk

    2014-01-01

    Full Text Available During colitis, activation of two inflammatory T cell subsets, Th17 and Th1 cells, promotes ongoing intestinal inflammatory responses. n-6 polyunsaturated fatty acid- (PUFA- derived eicosanoids, such as prostaglandin E2 (PGE2, promote Th17 cell-mediated inflammation, while n-3 PUFA antagonize both Th17 and Th1 cells and suppress PGE2 levels. We utilized two genetic mouse models, which differentially antagonize PGE2 levels, to examine the effect on Th17 cells and disease outcomes in trinitrobenzene sulfonic acid- (TNBS- induced colitis. Fat-1 mice contain the ω3 desaturase gene from C. elegans and synthesize n-3 PUFA de novo, thereby reducing the biosynthesis of n-6 PUFA-derived eicosanoids. In contrast, Fads1 Null mice contain a disrupted Δ5 desaturase gene and produce lower levels of n-6 PUFA-derived eicosanoids. Compared to Wt littermates, Fat-1 and Fads1 Null mice exhibited a similar colitic phenotype characterized by reduced colonic mucosal inflammatory eicosanoid levels and mRNA expression of Th17 cell markers (IL-17A, RORγτ, and IL-23, decreased percentages of Th17 cells and, improved colon injury scores (P≤0.05. Thus, during colitis, similar outcomes were obtained in two genetically distinct models, both of which antagonize PGE2 levels via different mechanisms. Our data highlight the critical impact of n-6 PUFA-derived eicosanoids in the promotion of Th17 cell-mediated colonic inflammation.

  4. Effects of arachidonic acid supplementation in maturation diet on female reproductive performance and larval quality of giant river prawn (Macrobrachium rosenbergii)

    Science.gov (United States)

    Pratoomyot, Jarunan; Siranonthana, Nisa; Senanan, Wansuk

    2016-01-01

    The giant river prawn (Macrobrachium rosenbergii) is one of the most farmed freshwater crustaceans in the world. Its global production has been stalling in the past decade due to the inconsistent quality of broodstock and hatchery-produced seeds. A better understanding of the role of nutrition in maturation diets will help overcome some of the production challenges. Arachidonic acid (20:4 n-6, ARA) is a fatty acid precursor of signaling molecules important for crustacean reproduction, prostaglandins E and F of the series II (PGE2 and PGF2α), and is often lacking in maturation diets of shrimp and prawns. We examined the effects of ARA in a combination of different fish oil (FO) and soybean oil (SO) blends on females’ reproductive performance and larval quality. Adult females (15.22 ± 0.13 g and 11.12 ± 0.09 cm) were fed six isonitrogenous and isolipidic diets containing one of two different base compositions (A or B), supplemented with one of three levels of Mortierella alpine-derived ARA (containing 40% active ARA): 0, 1 or 2% by ingredient weight. The two base diets differed in the percentages of (FO and SO with diet A containing 2% SO and 2% FO and diet B containing 2.5% SO and 1.5% FO, resulting in differences in proportional contents of dietary linoleic acid (18:2n-6, LOA) and docosahexaenoic acid (22:6n-3, DHA)). After the eight-week experiment, prawns fed diet B with 1 and 2% ARA supplement (B1 and B2) exhibited the highest gonadosomatic index (GSI), hepatosomatic index (HSI), egg clutch weight, fecundity, hatching rate, number of larvae, and reproductive effort compared to those fed other diets (p ≤ 0.05). Larvae from these two dietary treatments also had higher tolerance to low salinity (2 ppt). The maturation period was not significantly different among most treatments (p ≥ 0.05). ARA supplementation, regardless of the base diet, significantly improved GSI, HSI, egg clutch weight and fecundity. However, the diets with an enhanced ARA and LOA

  5. Effects of fluticasone propionate on arachidonic acid metabolites in BAL-fluid and methacholine dose-response curves in non-smoking atopic asthmatics

    Directory of Open Access Journals (Sweden)

    S. E. Overbeek

    1996-01-01

    Full Text Available Hyperresponsiveness of the airways to nonspecific stimuli is a characteristic feature of asthma. Airway responsiveness is usually characterized in terms of the position and shape of the dose–response curve to methacholine (MDR. In the study we have investigated the influence of fluticasone propionate (FP, a topically active glucocorticoid, on arachidonic acid (AA metabolites in broncho-alveolar lavage (BAL fluid (i.e. TxB2, PGE2, PGD2, 6kPGF1α and LTC4 on the one hand and MDR curves on the other hand. The effect of FP was studied in a randomized, double-blind, placebo-controlled design in 33 stable nonsmoking asthmatics; 16 patients received FP (500 μg b.i.d. whereas 17 patients were treated with placebo. We found that the forced expiratory volume in 1s (FEV1 % predicted increased, the log2PC20 methacholine increased and the plateau value (% fall in FEV1 decreased after a 12 week treatment period. No changes in AA-metabolites could be determined after treatment except for PGD2 which decreased nearly significantly (p = 0.058 within the FP treated group, whereas the change of PGD2 differed significantly (p = 0.05 in the FP treated group from placebo. The levels of the other AA metabolites (i.e. TxB2, PGE2, 6kPGF1α and LTC4 remained unchanged after treatment and were not significantly different from the placebo group. Our results support the hypothesis that although FP strongly influences the position, the shape and also the maximum response plateau of the MDR curve, this effect is not mainly achieved by influence on the level of AA metabolites. Other pro-inflammatory factors may be of more importance for the shape of the MDR curve. It is suggested that these pro-inflammatory factors are downregulated by FP.

  6. Role for calcium signaling and arachidonic acid metabolites in the activity-dependent increase of AHP amplitude in leech T sensory neurons.

    Science.gov (United States)

    Scuri, Rossana; Mozzachiodi, Riccardo; Brunelli, Marcello

    2005-08-01

    Previous studies have revealed a new form of activity-dependent modulation of the afterhyperpolarization (AHP) in tactile (T) neurons of the leech Hirudo medicinalis. The firing of T cells is characterized by an AHP, which is mainly due to the activity of the Na+/K+ ATPase. Low-frequency repetitive stimulation of T neurons leads to a robust increment of the AHP amplitude, which is correlated with a synaptic depression between T neuron and follower cells. In the present study, we explored the molecular cascades underlying the AHP increase. We tested the hypothesis that this activity-dependent phenomenon was triggered by calcium influx during neural activity by applying blockers of voltage-dependent Ca2+ channels. We report that AHP increase requires calcium influx that, in turn, induces release of calcium from intracellular stores so sustaining the enhancement of AHP. An elevation of the intracellular calcium can activate the cytosolic isoforms of the phosholipase A2 (PLA2). Therefore we analyzed the role of PLA2 in the increase of the AHP, and we provide evidence that not only PLA2 but also the recruitment of arachidonic acid metabolites generated by the 5-lipoxygenase pathway are necessary for the induction of AHP increase. These data indicate that a sophisticated cascade of intracellular signals links the repetitive discharge of T neurons to the activation of molecular pathways, which finally may alter the activity of critical enzymes such as the Na+/K+ ATPase, that sustains the generation of the AHP and its increase during repetitive stimulation. These results also suggest the potential importance of the poorly studied 5-lipoxygenase pathway in forms of neuronal plasticity.

  7. Flurbiprofen, a cyclooxygenase inhibitor, reduces the brain arachidonic acid signal in response to the cholinergic muscarinic agonist, arecoline, in awake rats.

    Science.gov (United States)

    Basselin, Mireille; Villacreses, Nelly E; Lee, Ho-Joo; Bell, Jane M; Rapoport, Stanley I

    2007-11-01

    Cholinergic muscarinic receptors, when stimulated by arecoline, can activate cytosolic phospholipase A(2) (cPLA(2)) to release arachidonic acid (AA) from membrane phospholipid. This signal can be imaged in the brain in vivo using quantitative autoradiography following the intravenous injection of radiolabeled AA, as an increment in a regional brain AA incorporation coefficient k*. Arecoline increases k* significantly in brain regions having muscarinic M(1,3,5) receptors in wild-type but not in cyclooxygenase (COX)-2 knockout mice. To further clarify the roles of COX enzymes in the AA signal, in this paper we imaged k* following arecoline (5 mg/kg i.p.) or saline in each of 81 brain regions of unanesthetized rats pretreated 6 h earlier with the non-selective COX inhibitor flurbiprofen (FB, 60 mg/kg s.c.) or with vehicle. Baseline values of k* were unaffected by FB treatment, which however reduced by 80% baseline brain concentrations of prostaglandin E(2) (PGE(2)) and thromboxane B(2) (TXB(2)), eicosanoids preferentially derived from AA via COX-2 and COX-1, respectively. In vehicle-pretreated rats, arecoline increased the brain PGE(2) but not TXB(2) concentration, as well as values for k* in 77 of the 81 brain regions. FB-pretreatment prevented these arecoline-provoked changes. These results and those reported in COX-2 knockout mice suggest that the AA released in brain following muscarinic receptor-mediated activation is lost via COX-2 to PGE(2) but not via COX-1 to TXB(2), and that increments in k* following arecoline largely represent replacement by unesterified plasma AA of this loss.

  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).

    Science.gov (United States)

    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.

  9. Effect of dietary arachidonic acid, eicosapentaenoic acid and docosahexaenoic acid on survival, growth and pigmentation in larvae of common sole ( Solea solea L.)

    DEFF Research Database (Denmark)

    Lund, Ivar; Steenfeldt, Svend Jørgen; Hansen, B.W.

    2007-01-01

    reflected dietary composition, neither standard growth nor larval survival were significantly related to the absolute concentrations of ARA, EPA and DHA or their ratios. This suggests low requirements for essential polyunsaturated fatty acids (PUFAs) in common sole. Malpigmentation was significantly related...... to increased dietary ARA content. However, pigmentation was not affected by inclusion levels of EPA or DHA when ARA was high. This, and no relation between DHA: EPA or ARA: EPA ratios and pigmentation and only a weak relation to ARA: DHA ratio, advocate for that it is the absolute concentration of ARA...... resulted in a lower growth rate, which suggests that visual aberrations affected prey capture. (C) 2007 Elsevier B.V. All rights reserved....

  10. The application of arachidonic acid in dairy products%花生四烯酸在乳制品中的应用

    Institute of Scientific and Technical Information of China (English)

    詹现璞; 吕银德; 赵俊芳

    2009-01-01

    花生四烯酸(AA)是一种人体必需的多不饱和脂肪酸,是人体生长因子,影响婴幼儿大脑和神经发育.AA具有改善记忆力和视力、调节血脂和血糖、降低血清胆固醇、预防心血管疾病、辅助抑制肿瘤、预防癌变、神经功能调节等作用.人体自身不能合成AA,必需从食物补充才能满足机体代谢的需要,牛乳是人体补充营养物质的载体,而AA在牛乳中几乎不存在,所以在牛乳中强化AA已显得非常必要.本文介绍了AA添加带配方奶粉中的工艺流程和操作要点;AA应用于纯牛奶中的工艺流程和操作要点;开发富含AA酸牛奶的生产工艺和操作要点;开发富含AA乳饮料的工艺流程和操作要点.研究发现,AA在酸牛奶和乳饮料中的应用将是新的发展趋势,富含AA的乳制品将会给企业带来巨大的经济效益和社会效益.%Arachidonic acid(AA)is an essential polyunsaturated fatty acids for human.It is a human growth factor,which can greatly affect infant brain and neurological development.AA can improve the memory and vision,regulate blood lipids and blood sugar,reduce cholesterol,and prevent cardiovascular disease and cancer.AA can not be synthesized by human body,it can only be obtained through food.Milk contains rich nutrients except AA,so AA fortified milk has become necessary.In this paper,the formula and process for adding AA into milk has been studied.It is found that AA in the acidophilus milk and milk drinks will be the new trend of dairy products.AA enrichment products will bring enormous economic and social benefits.

  11. Essential function of linoleic acid esterified in acylglucosylceramide and acylceramide in maintaining the epidermal water permeability barrier. Evidence from feeding studies with oleate, linoleate, arachidonate, columbinate and a-linolenate

    DEFF Research Database (Denmark)

    Hansen, Harald S.; Jensen, B.

    1985-01-01

    Essential fatty acid-deficient rats were supplemented with 300 mg per day of pure fatty acid esters: oleate (O), linoleate (L), arachidonate (A), and columbinate (C) for 10 days. During this period, the rats in groups L, A, and C all showed a decrease in their initially high trans-epidermal water...... loss, a classical essential fatty acid-deficiency symptom, to a level seen in non-deficient rats (group N). The trans-epidermal water loss in rats of group O was unaffected by the supplementation. Fatty acid composition of two epidermal sphingolipids, acylglucosylceramide and acylceramide, from...... the skin were determined. The results indicate that re-establishment of a low trans-epidermal water loss was associated with incorporation of linolenate into the two epidermal sphingolipids. Supplementation with columbinate resulted in relatively high amounts of this fatty acid in the investigated...

  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.

    Science.gov (United States)

    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. An arachidonic acid-enriched diet does not result in more colonic inflammation as compared with fish oil- or oleic acid-enriched diets in mice with experimental colitis.

    Science.gov (United States)

    Ramakers, Julian D; Mensink, Ronald P; Verstege, Marleen I; te Velde, Anje A; Plat, Jogchum

    2008-08-01

    Fish oils (FO) - rich in EPA and DHA - may protect against colitis development. Moreover, inflammatory bowel disease patients have elevated colonic arachidonic acid (AA) proportions. So far, effects of dietary AA v. FO on colitis have never been examined. We therefore designed three isoenergetic diets, which were fed to mice for 6 weeks preceding and during 7 d dextran sodium sulfate colitis induction. The control diet was rich in oleic acid (OA). For the other two diets, 1.0 % (w/w) OA was exchanged for EPA+DHA (FO group) or AA. At 7 d after colitis induction, the AA group had gained weight (0.46 (sem 0.54) g), whereas the FO and OA groups had lost weight (- 0.98 (SEM 0.81) g and - 0.79 (SEM 1.05) g, respectively; P diet increased colonic AA content, but did not result in more colonic inflammation as compared with FO- and OA-enriched diets. As we only examined effects after 7 d and because the time point for evaluating effects seems to be important, the present results should be regarded as preliminary. Future studies should further elucidate differential effects of fatty acids on colitis development in time.

  14. Cross-ecosystem fluxes: Export of polyunsaturated fatty acids from aquatic to terrestrial ecosystems via emerging insects.

    Science.gov (United States)

    Martin-Creuzburg, Dominik; Kowarik, Carmen; Straile, Dietmar

    2017-01-15

    Cross-ecosystem fluxes can crucially influence the productivity of adjacent habitats. Emerging aquatic insects represent one important pathway through which freshwater-derived organic matter can enter terrestrial food webs. Aquatic insects may be of superior food quality for terrestrial consumers because they contain high concentrations of essential polyunsaturated fatty acids (PUFA). We quantified the export of PUFA via emerging insects from a midsize, mesotrophic lake. Insects were collected using emergence traps installed above different water depths and subjected to fatty acid analyses. Insect emergence from different depth zones and seasonal mean fatty acid concentrations in different insect groups were used to estimate PUFA fluxes. In total, 80.5mg PUFA m(-2)yr(-1) were exported, of which 32.8mgm(-2)yr(-1) were eicosapentaenoic acid (EPA), 7.8mgm(-2)yr(-1) were arachidonic acid (ARA), and 2.6mgm(-2)yr(-1) were docosahexaenoic acid (DHA). While Chironomidae contributed most to insect biomass and total PUFA export, Chaoborus flavicans contributed most to the export of EPA, ARA, and especially DHA. The export of total insect biomass from one square meter declined with depth and the timing at which 50% of total insect biomass emerged was correlated with the water depths over which the traps were installed, suggesting that insect-mediated PUFA fluxes are strongly affected by lake morphometry. Applying a conceptual model developed to assess insect deposition rates on land to our insect-mediated PUFA export data revealed an average total PUFA deposition rate of 150mgm(-2)yr(-1) within 100m inland from the shore. We propose that PUFA export can be reliably estimated using taxon-specific information on emergent insect biomass and seasonal mean body PUFA concentrations of adult insects provided here. Our data indicate that insect-mediated PUFA fluxes from lakes are substantial, implying that freshwater-derived PUFA can crucially influence food web processes in adjacent

  15. 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.

    Science.gov (United States)

    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.

  16. Synthesis of (9Z, 12E-, (9E, 12Z-[1-14C]-linoleic acid, (9Z, 12Z, 15E-, (9E, 12Z, 15Z-[1-14C]-linolenic acid and (5Z, 8Z, 11Z, 14E-[1-14C]-arachidonic acid

    Directory of Open Access Journals (Sweden)

    Enard, Thierry

    1996-04-01

    Full Text Available Trans polyunsaturated fatty acids are produced in vegetable oils during heat treatment (240-250 °C.ln order to study the metabolic pathway of 9c, 12t and 9t, 12c linoleic acid and 9c, 12c, 15t and 9t, 12c, 15c linolenic acid, these products were prepared labelled with carbon 14 in the carboxylic position. 5c, 8c, 11c, 14t-Arachidonic acid was also labelled on the carboxylic position with carbon 14 in order to study its physiological effects. To introduce the labelling (E-bromo precursors with a 17 carbons chain or a 19 carbon chain were needed. The different syntheses were done by elongation steps and creation of cis double bonds via highly stereospecific Wittig reactions. The radioactive carbon atom was introduced from [14C]-potassium cyanide. The final radioactive fatty acids had a specific activity greater than 50 mCi/mmol and a radioactive purity better than 99 % for linoleic and linolenic and better than 98.6 % for arachidonic acid.

  17. beta-oxidation modulates metabolic competition between eicosapentaenoic acid and arachidonic acid regulating prostaglandin E(2) synthesis in rat hepatocytes-Kupffer cells

    DEFF Research Database (Denmark)

    Du, Zhen-Yu; Ma, Tao; Winterthun, Synnøve

    2010-01-01

    and eicosapentaenoic acid (EPA) for PGE(2) synthesis in a rat hepatocyte-Kupffer cell (HPC/KC) co-culture system when the cellular oxidation capacity was enhanced by exogenous l-carnitine. We demonstrate that in the absence of l-carnitine, 1) beta-oxidation rates of EPA and AA were comparable in HPCs and in KCs; 2) AA...... and not EPA was preferentially incorporated into glycerolipids; and 3) addition of EPA significantly decreased AA-dependent PGE(2) synthesis in HPCs and cyclooxygenase-2 (COX-2) expression in co-cultured HPCs/KCs. However, enhancing the cellular oxidation capacity by the addition of l-carnitine 1...

  18. Recent advances on the correlation between 5-LOX pathway of arachidonic acid and periodontitis%5-LOX代谢途径与牙周炎相关性的研究进展

    Institute of Scientific and Technical Information of China (English)

    罗华珍

    2015-01-01

    The metabolism of arachidonic acid plays a signiifcant role in the pathological process of inlfammatory bone destruction disease. The main pathomechanism is osteoclast formation and activation. In recent years, evidence suggests that the level of LTB4 metabolized by LOX enzymatic pathway is elevated in gingival crevicular fluid of patients with periodontitis compared with periodontal health. Giving inhibitor of 5-LOX to the inlfammation model showed that the number of osteoclast and the degree of bone destruction are al below when compared with normal control. Therefore, discuss arachidonic acid metabolized by 5-LOX enzymatic pathway how to influence as wel as mechanism on periodontitis wil be conducive to expound pathogenesis of periodontitis. It proposes a new idea for the prevention and treatment of periodontitis. In this article the relationship between 5-LOX pathway of arachidonic acid and periodontitis will be reviewed.%花生四烯酸的代谢产物在炎症性骨破坏疾病的病理过程中发挥着重的作用,其主病理机制为破骨细胞的形成和活化,近年来发现花生四烯酸经脂氧酶(1ipoxygenase,LOX)途径代谢的产物LTB4在牙周炎患者龈沟液中的含量高于正常者,给予5-LOX抑制剂的炎症模型中破骨细胞的数量和骨破坏的程度均低于对照组,因而探讨花生四烯酸经5-LOX途径代谢对牙周炎的影响及其机制将有利于进一步阐明牙周炎的发病机理,为牙周炎的防治提出新的思路,本文就有关花生四烯酸脂氧酶代谢途径与牙周炎关系的研究做一综述.

  19. Inhibitory effects of Tabebuia impetiginosa inner bark extract on platelet aggregation and vascular smooth muscle cell proliferation through suppressions of arachidonic acid liberation and ERK1/2 MAPK activation.

    Science.gov (United States)

    Son, Dong-Ju; Lim, Yong; Park, Young-Hyun; Chang, Sung-Keun; Yun, Yeo-Pyo; Hong, Jin-Tae; Takeoka, Gary R; Lee, Kwang-Geun; Lee, Sung-Eun; Kim, Mi-Ran; Kim, Jeong-Han; Park, Byeoung-Soo

    2006-11-03

    The antiplatelet and antiproliferative activities of extract of Tabebuia impetiginosa inner bark (taheebo) were investigated using washed rabbit platelets and cultured rat aortic vascular smooth muscle cells (VSMCs) in vitro. n-Hexane, chloroform and ethyl acetate fractions showed marked and selective inhibition of platelet aggregation induced by collagen and arachidonic acid (AA) in a dose-dependent manner. These fractions, especially the chloroform fraction, also significantly suppressed AA liberation induced by collagen in [(3)H]AA-labeled rabbit platelets. The fractions, especially the chloroform fraction, potently inhibited cell proliferation and DNA synthesis induced by platelet derived growth factor (PDGF)-BB, and inhibited the levels of phosphorylated extracellular signal regulated kinase (ERK1/2) mitogen activated protein kinase (MAPK) stimulated by PDGF-BB, in the same concentration range that inhibits VSMC proliferation and DNA synthesis.

  20. Effects of arachidonic acid on L-type calcium channel and its mechanism of antiarrhythmia%花生四烯酸对L-型钙通道的作用及其抗心律失常机制

    Institute of Scientific and Technical Information of China (English)

    刘承云; 陈桂青; 耿小晶; 陈心; 万晶晶

    2009-01-01

    目的 研究花生四烯酸(arachidonic acid,AA)对家兔单个心室肌细胞L-广型钙通道的作用及其抗心律失常作用的机制.方法 采用酶解法分离得到家兔单个心室肌细胞,全细胞膜片钳技术记录单个心室肌细胞L-型钙电流(L-type calcium current,Ica-L),用累积给药的方法在灌流液中加入不同浓度的AA,观察给药前后L-型钙电流的变化,统计学方法采用单因素方差分析.结果 不同浓度的从均能明显抑制心室肌细胞,Ica-L.3 μmol/L,μmol/L,20,μmol/L的AA使Ica-L峰电流密度从(10.79±0.93)pA/pF分别减少剑(8.99 ±0.43)pA/pF、(7.60 ±0.35)pA/pF和(5.60±0.30)pA/pF(n=7,P<0.05),经冲洗后Ica-L可部分恢复,并且AA可使Ica-L的I-V关系曲线上移,其形状和峰值电压保持不变;20 μmol/L的AA使Ica-L失活曲线左移,失活后恢复时间明显延长,但对激活曲线无明显影响.结论 花生四烯酸可通过加快L-型钙通道失活,延长其失活后的恢复过程而减少细胞外钙离子的内流,延长有效不应期,从而发挥抗心律失常作用.%Objective To study the influence of arachidonic acid (AA) on L-type calcium channel in rabbits sin-gle cardiomyocyte and its mechanism of antiarrhythmia. Method The single ventricular cardiomyocyte was isolat-ed by using enzyme dispersion method and whole-cell clamp-patch technique was used to record L-type calcium current.All data were analyzed using ANOVA. Results AA inhibited Ica-L in a concentration-dependent manner. The application of 3 μmol/L, 10 μmol/L and 20 μmol/L arachidonic acid reduced the density of peak Ica-L from (10.79±0.93)pA/pF to (8.99±0.43)pA/pF to (7.60±0.35)pA/pF and to (5.60±0.30)pA/pF, respctive-ly (n=7, P<0. O1 ). The Ica-Lpartially resumed after washout. The AA up-shifted the I-V curves of Ica-L without changes of their shape,peak and reverse potentials. The AA also markedly shifted the inactivation curve to left, and prolonged the recorvery time from inactivation

  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

    Directory of Open Access Journals (Sweden)

    Corsetto Paola

    2010-01-01

    Full Text Available Abstract 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.

  2. Enhanced fatty acid flux triggered by adiponectin overexpression.

    Science.gov (United States)

    Shetty, Shoba; Ramos-Roman, Maria A; Cho, You-Ree; Brown, Jonathan; Plutzky, Jorge; Muise, Eric S; Horton, Jay D; Scherer, Philipp E; Parks, Elizabeth J

    2012-01-01

    Adiponectin overexpression in mice increases insulin sensitivity independent of adiposity. Here, we combined stable isotope infusion and in vivo measurements of lipid flux with transcriptomic analysis to characterize fatty acid metabolism in transgenic mice that overexpress adiponectin via the aP2-promoter (ADNTg). Compared with controls, fasted ADNTg mice demonstrated a 31% reduction in plasma free fatty acid concentrations (P = 0.008), a doubling of ketones (P = 0.028), and a 68% increase in free fatty acid turnover in plasma (15.1 ± 1.5 vs. 25.3 ± 6.8 mg/kg · min, P = 0.011). ADNTg mice had 2-fold more brown adipose tissue mass, and triglyceride synthesis and turnover were 5-fold greater in this organ (P = 0.046). Epididymal white adipose tissue was slightly reduced, possibly due to the approximately 1.5-fold increase in the expression of genes involved in oxidation (peroxisome proliferator-activated receptor α, peroxisome proliferator-activated receptor-γ coactivator 1α, and uncoupling protein 3). In ADNTg liver, lipogenic gene expression was reduced, but there was an unexpected increase in the expression of retinoid pathway genes (hepatic retinol binding protein 1 and retinoic acid receptor beta and adipose Cyp26A1) and liver retinyl ester content (64% higher, P < 0.02). Combined, these data support a physiological link between adiponectin signaling and increased efficiency of triglyceride synthesis and hydrolysis, a process that can be controlled by retinoids. Interactions between adiponectin and retinoids may underlie adiponectin's effects on intermediary metabolism.

  3. 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*

    Science.gov (United States)

    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

  4. 品种与部位对羊肌肉中亚麻酸与花生四烯酸含量的影响%Study on the Linolenic Acid and Arachidonic Acid Content in Different Breeds and Parts of Sheep

    Institute of Scientific and Technical Information of China (English)

    罗玉龙; 杨晶; 刘夏炜; 靳志敏; 段艳; 靳烨

    2015-01-01

    Linolenic acid and Arachidonic acid content of biceps femoris,triceps brachii and longissimus dorsi from 5 months Sunite sheep,Small tailed han sheep and Bahan F2 sheep were detected by gas chromatography to explore the effect of breeds and anatomical locations.The results showed breeds and anatomical locations had significantly influence on Linolenic acid and Arachidonic acid content.Content of Linolenic acid was the highest in the longissimus muscles of Small tailed han sheep;In the same breed,Arachidonic acid content in the longissimus dorsi significantly higher than other anatomical locations.In the different breeds,content of Arachidonic acid in Sunite sheep was higher than other breeds.Compared comprehensively,content of Arachidonic acid in the longissimus dorsi of Sunite lamb was the highest.As the standard evaluation of mutton nutrition value,meat of Sunite sheep was the better than meat of Small tailed han sheep and Bahan F2 sheep,the longissimus dorsi of Sunite sheep was best.%通过选择5月龄苏尼特羊、小尾寒羊及巴寒F2各5只,每只羊就其背最长肌,股二头肌、臂三头肌3个部位用气相色谱法测定其脂肪酸含量,来进一步研究不同品种不同部位羊肉亚麻酸与花生四烯酸的含量,阐明品种及部位对羊肉中亚麻酸与花生四烯酸含量的影响.结果表明:品种和部位都对羊肉中亚麻酸与花生四烯酸的含量有一定影响,小尾寒羊背最长肌部位的亚麻酸含量最高;同一品种,背最长肌部位花生四烯酸含量显著高于其他部位.不同品种的羊,苏尼特羊的花生四烯酸含量高于小尾寒羊和巴寒F2,综合比较得出苏尼特羊背最长肌部位的花生四烯酸含量最高.以这2种酸作为评价羊肉营养价值的标准时,苏尼特肉质较小尾寒羊和巴寒F2好,其中背最长肌肉质为最佳.

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

    Science.gov (United States)

    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...

  6. Virus-induced enhancement of arachidonate metabolism by bovine alveolar macrophages in vitro

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-04-01

    Virus infection of alveolar macrophages both in vivo and in vitro has been associated with a variety of changes in cellular function. Some of these changes are identical to the effects that arachidonate-derived mediators, prostaglandins, leukotrienes, and hydroxyeicosatetraenoic acids, have on macrophage function. Virus infection of macrophages has been previously shown to increase the output of some arachidonate metabolites, most notably PGE2. However, the effect of virus infection on arachidonate metabolism in general has not been well described. In our experiments, primary cultures of alveolar macrophages obtained from normal cattle by bronchoalveolar lavage, were infected in vitro with parainfluenza type 3 virus. At days 0 to 4 post-infection (p.i.) these cells were labelled with 3H-arachidonic acid and stimulated with either serum-coated zymosan, the calcium ionophore A23187, or phorbol myristate acetate. The complete spectrum of arachidonate-derived metabolites was determined by reverse-phase high performance liquid chromatography with UV and on-line radiometric monitoring of column eluant. The total output of metabolites of arachidonic acid by virus-infected alveolar macrophages was increased over that of noninfected controls (with all stimuli tested) by day 4 p.i. (P less than or equal to 0.05). The production of metabolites by the cyclooxygenase, 12- and 5-lipoxygenase enzyme systems was significantly increased, as was the release of 3H-arachidonate. The lack of stimulus specificity and the increases in arachidonate release suggest that greater substrate availability, due either to increased phospholipase activity or direct virus-membrane interaction, may be responsible for the virus-induced enhancement of metabolite output.

  7. Arachidonic acid induces Fas and FasL upregulation in human leukemia U937 cells via Ca2+/ROS-mediated suppression of ERK/c-Fos pathway and activation of p38 MAPK/ATF-2 pathway.

    Science.gov (United States)

    Liu, Wen-Hsin; Chang, Long-Sen

    2009-12-15

    Arachidonic acid (AA)-induced apoptotic death of human leukemia U937 cells was characteristic of increase in intracellular Ca(2+) concentration ([Ca(2+)]i), ROS generation, ERK inactivation, p38 MPAK activation, degradation of procaspase-8 and production of truncated Bid (tBid). Moreover, AA treatment upregulated Fas/FasL protein expression and transcription of Fas/FasL mRNA. Downregulation of FADD blocked AA-induced procaspase-8 degradation and rescued viability of AA-treated cells. BAPTA-AM (Ca(2+) chelator) pretreatment abolished AA-induced ROS generation, while N-acetylcysteine (NAC, ROS scavenger) was unable to alter AA-elicited [Ca(2+)]i increase. Pretreatment with BAPTA-AM or NAC abrogated p38 MAPK activation and restored ERK activation. Suppression of p38 MAPK or transfection of constitutively active MEK1 abolished AA-induced Fas and FasL upregulation. AA treatment repressed ERK-mediated c-Fos phosphorylation but evoked p38 MAPK-mediated ATF-2 phosphorylation. Knockdown of c-Fos and ATF-2 by siRNA reflected that c-Fos counteracted the effect of ATF-2 on Fas/FasL upregulation. Taken together, our data indicate that Fas/FasL upregulation in AA-treated U937 cells is elicited by Ca(2+)/ROS-mediated suppression of ERK/c-Fos pathway and activation of p38 MAPK/ATF-2, and suggest that autocrine Fas-mediated apoptotoic mechanism is involved in AA-induced cell death.

  8. Difference in expression between AQP1 and AQP5 in porcine endometrium and myometrium in response to steroid hormones, oxytocin, arachidonic acid, forskolin and cAMP during the mid-luteal phase of the estrous cycle and luteolysis.

    Science.gov (United States)

    Skowronska, Agnieszka; Mlotkowska, Patrycja; Nielsen, Soren; Skowronski, Mariusz T

    2015-12-01

    Recently, we demonstrated in vitro that AQP1 and AQP5 in the porcine uterus are regulated by steroid hormones (P4, E2), arachidonic acid (AA), forskolin (FSK) and cAMP during the estrous cycle. However, the potential of the porcine separated uterine tissues, the endometrium and myometrium, to express these AQPs remains unknown. Thus, in this study, the responses of AQP1 and AQP5 to P4, E2 oxytocin (OT), AA, FSK and cAMP in the porcine endometrium and myometrium were examined during the mid-luteal phase of the estrous cycle and luteolysis. Real-time PCR and western blot analysis. Progesterone up-regulated the expression of AQP1/AQP5 mRNAs and proteins in the endometrium and myometrium, especially during luteolysis. Similarly, E2 also stimulated the expression of both AQPs, but only in the endometrium. AA led to the upregulation of AQP1/AQP5 in the endometrium during luteolysis. In turn, OT increased the expression of AQP1/AQP5 mRNAs and proteins in the myometrium during mid-luteal phase. Moreover, a stimulatory effect of forskolin and cAMP on the expression of AQP1/AQP5 mRNAs and proteins in the endometrium and myometrium dominated during luteolysis, but during the mid-luteal phase their influence on the expression of these AQPs was differentiated depending on the type of tissue and the incubation duration. These results seem to indicate that uterine tissues; endometrium and myometrium, exhibit their own AQP expression profiles in response to examined factors. Moreover, the responses of AQP1/AQP5 at mRNA and protein levels to the studied factors in the endometrium and myometrium are more pronounced during luteolysis. This suggests that the above effects of the studied factors are connected with morphological and physiological changes taking place in the pig uterus during the estrous cycle.

  9. Effect of resveratrol, tyrosol and beta-sitosterol on oxidised low-density lipoprotein-stimulated oxidative stress, arachidonic acid release and prostaglandin E2 synthesis by RAW 264.7 macrophages.

    Science.gov (United States)

    Vivancos, Marta; Moreno, Juan J

    2008-06-01

    Oxidation of LDL is hypothesised as an early and critical event in atherogenesis. Oxidised LDL (oxLDL) favour the transformation of macrophages into foam cells, an important cell involved in atherosclerosis. Furthermore, oxLDL cause multiple changes in macrophage functions. Thus, oxLDL induces certain genes, suppresses others and alters cell lipid metabolism. Consumption of a Mediterranean diet is associated with a low incidence of atherosclerotic disease, but data about the specific dietary constituents involved and mechanisms conferring cardioprotection are still sparse. The aim of the present study was to determine the effect of representative minor components of wine and olive oil on reactive oxygen species and eicosanoid synthesis induced by oxLDL-stimulated macrophages. We observed that exposure to non-toxic oxLDL concentrations leads to the production of H2O2 by RAW 264.7 macrophages and this effect was reverted by apocynin, a NADPH oxidase inhibitor. Moreover, oxLDL induced arachidonic acid (AA) release, cyclo-oxygenase-2 overexpression and subsequent PGE2 release. We observed that resveratrol and tyrosol revert H2O2 production induced by oxLDL as well as AA release and PGE2 synthesis and that these effects were not as a consequence of these compounds interfering with the oxLDL binding to their receptors. Interestingly, beta-sitosterol presence enhances these polyphenol actions. Thus, we found a synergistic action of polyphenols of olive oil and wine and beta-sitosterol of olive oil led to the modulation of the effects of oxLDL on oxidative stress and PGE2 synthesis.

  10. Interpreting expression data with metabolic flux models: predicting Mycobacterium tuberculosis mycolic acid production.

    Directory of Open Access Journals (Sweden)

    Caroline Colijn

    2009-08-01

    Full Text Available Metabolism is central to cell physiology, and metabolic disturbances play a role in numerous disease states. Despite its importance, the ability to study metabolism at a global scale using genomic technologies is limited. In principle, complete genome sequences describe the range of metabolic reactions that are possible for an organism, but cannot quantitatively describe the behaviour of these reactions. We present a novel method for modeling metabolic states using whole cell measurements of gene expression. Our method, which we call E-Flux (as a combination of flux and expression, extends the technique of Flux Balance Analysis by modeling maximum flux constraints as a function of measured gene expression. In contrast to previous methods for metabolically interpreting gene expression data, E-Flux utilizes a model of the underlying metabolic network to directly predict changes in metabolic flux capacity. We applied E-Flux to Mycobacterium tuberculosis, the bacterium that causes tuberculosis (TB. Key components of mycobacterial cell walls are mycolic acids which are targets for several first-line TB drugs. We used E-Flux to predict the impact of 75 different drugs, drug combinations, and nutrient conditions on mycolic acid biosynthesis capacity in M. tuberculosis, using a public compendium of over 400 expression arrays. We tested our method using a model of mycolic acid biosynthesis as well as on a genome-scale model of M. tuberculosis metabolism. Our method correctly predicts seven of the eight known fatty acid inhibitors in this compendium and makes accurate predictions regarding the specificity of these compounds for fatty acid biosynthesis. Our method also predicts a number of additional potential modulators of TB mycolic acid biosynthesis. E-Flux thus provides a promising new approach for algorithmically predicting metabolic state from gene expression data.

  11. Flux balance analysis in the production of clavulanic acid by Streptomyces clavuligerus.

    Science.gov (United States)

    Sánchez, Claudia; Quintero, Juan Carlos; Ochoa, Silvia

    2015-01-01

    In this work, in silico flux balance analysis is used for predicting the metabolic behavior of Streptomyces clavuligerus during clavulanic acid production. To choose the best objective function for use in the analysis, three different optimization problems are evaluated inside the flux balance analysis formulation: (i) maximization of the specific growth rate, (ii) maximization of the ATP yield, and (iii) maximization of clavulanic acid production. Maximization of ATP yield showed the best predictions for the cellular behavior. Therefore, flux balance analysis using ATP as objective function was used for analyzing different scenarios of nutrient limitations toward establishing the effect of limiting the carbon, nitrogen, phosphorous, and oxygen sources on the growth and clavulanic acid production rates. Obtained results showed that ammonia and phosphate limitations are the ones most strongly affecting clavulanic acid biosynthesis. Furthermore, it was possible to identify the ornithine flux from the urea cycle and the α-ketoglutarate flux from the TCA cycle as the most determinant internal fluxes for promoting clavulanic acid production.

  12. Arachidonic acid and lipoxinA4 attenuate streptozotocin-induced cytotoxicity to RIN5 F cells in vitro and type 1 and type 2 diabetes mellitus in vivo.

    Science.gov (United States)

    Gundala, Naveen K V; Naidu, Vegi G M; Das, Undurti N

    2017-03-01

    The aim of this study was to observe whether polyunsaturated fatty acids (PUFAs) can protect rat insulinoma (RIN5 F) cells against streptozotocin (STZ)-induced apoptosis in vitro and type 1 diabetes mellitus (T1DM) and type 2 DM (T2DM) in vivo and if so, what would be the mechanism of this action. RIN5 F cells were used for the in vitro study, whereas the in vivo study was performed in Wistar rats. STZ was used to induce apoptosis of RIN5 F cells in vitro and T1- and T2DM in vivo. The effect of PUFAs: γ-linolenic acid (GLA), arachidonic acid (AA) of ω-6 series, and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) of ω-3 series; cyclooxygenase (COX) and lipoxygenase (LOX) inhibitors and antiinflammatory metabolite of AA and DHA, lipoxin A4 (LXA4), and resolvin D2 and protectin, respectively against STZ-induced cytotoxicity to RIN5 F cells in vitro and LXA4 against T1- and T2DM in vivo was studied. Changes in the antioxidant content, lipid peroxides, nitric oxide, and expression of PDX1, P65, nuclear factor-κb (NF-κb), and IKB genes in STZ-treated RIN5 F cells in vitro and Nrf2, GLUT2, COX2, iNOS protein levels in the pancreatic tissue of T1- and T2DM and LPCLN2 (lipocalin 2), NF-κb, IKB I in adipose tissue of T2DM after LXA4 treatment were studied. Plasma glucose, insulin, and tumor necrosis factor (TNF)-α levels also were measured in STZ-induced T1- and T2DM Wistar rats. Among all PUFAs tested, AA and EPA are the most effective against STZ-induced cytotoxicity to RIN5 F cells in vitro. Neither COX nor LOX inhibitors blocked the cytoprotective action of AA in vitro and T1- and T2DM by STZ. LXA4 production by RIN5 F cells in vitro and plasma LXA4 levels in STZ-induced T1- and T2DM animals were decreased by STZ that reverted to normal after AA treatment. AA prevented both T1- and T2DM induced by STZ. Antiinflammatory metabolite of AA and LXA4 prevented both T1- and T2DM induced by STZ. The expression of Pdx1, NF-κb, IKB genes in the

  13. 花生四烯酸、二十二碳六烯酸和二十碳五烯酸在炎症中的作用概述%Roles of arachidonic acid, docosahexaenoic acid and eicosapentaenoic acid in inflammation

    Institute of Scientific and Technical Information of China (English)

    柳泽深; 姜悦; 陈峰

    2016-01-01

    心脑血管疾病、肿瘤、糖尿病、神经系统疾病、自身免疫等疾病严重危害着人类的生命和健康,并消耗着大量医疗资源。事实上,很多疾病发生和发展的背后都伴随着炎症反应,炎症是众多疾病的病理基础,甚至是导致这些疾病的诱因。炎症本身是机体的防御性反应,但过度的炎症反应和长期慢性炎症会损害机体的稳态。炎症的调节和控制由炎症介质介导,花生四烯酸(arachidonic acid, AA)、二十二碳六烯酸(docosahexaenoic acid, DHA)和二十碳五烯酸(eicosapentaenoic acid, EPA)等长链多不饱和脂肪酸(long-chain polyunsaturated fatty acids, LC-PUFAs)的衍生物是一类重要的调控炎症的介质。炎性细胞间的交流和细胞内信号传递与LC-PUFAs有关。AA经环氧酶和脂氧合酶合成的类二十烷酸主要起促炎作用,但有的也有抗炎作用。DHA和EPA在体内起抗炎作用,由它们合成的消退素(resolvins, Rvs)和保护素(protectin, PD)是重要的抗炎活性物质。DHA和EPA还可以干扰炎性细胞内信号传导途径来抑制炎症反应。本文从炎症与疾病的关系、LC-PUFAs的衍生物及其促炎和抗炎机制等方面综述了AA、DHA和EPA在炎症中的作用。%ABSTRACT:Cardiovascular disease, cancer, diabetes, neurological diseases and autoimmune disease are major threat to human health and long life, and a large amount of medical resources are consumed on the treatment of these diseases. In fact, the progression of these diseases is pointed out to be accompanied by inflammatory response, and inflammation is regarded as pathological basis of many diseases. Normally inflammation itself is a defensive reaction of body, but excessive inflammatory response and chronic inflammation can damage organ homeostasis. On the other side, regulation and control of inflammation can be mediated by inflammatory mediators. It is indicated that derivatives of long-chain polyunsaturated fatty acids

  14. Progesterone, estradiol, arachidonic acid, oxytocin, forskolin and cAMP influence on aquaporin 1 and 5 expression in porcine uterine explants during the mid-luteal phase of the estrous cycle and luteolysis: an in vitro study.

    Science.gov (United States)

    Skowronska, Agnieszka; Młotkowska, Patrycja; Wojciechowicz, Bartosz; Okrasa, Stanisław; Nielsen, Soren; Skowronski, Mariusz T

    2015-02-18

    The cell membrane water channel protein, aquaporins (AQPs), regulate cellular water transport and cell volume and play a key role in water homeostasis. Recently, AQPs are considered as important players in the field of reproduction. In previous studies, we have established the presence of AQP1 and 5 in porcine uterus. Their expression at protein level altered in distinct tissues of the female reproductive system depending on the phase of the estrous cycle. However, the regulation of aquaporin genes and proteins expression has not been examined in porcine uterine tissue. Therefore, we have designed an in vitro experiment to explain whether steroid hormones, progesterone (P4) and estradiol (E2), and other factors: oxytocine (OT), arachidonic acid (AA; substrate for prostaglandins synthesis) as well as forskolin (FSK; adenylate cyclase activator) and cAMP (second messenger, cyclic adenosine monophosphate) may impact AQPs expression. Uterine tissues were collected on Days 10-12 and 14-16 of the estrous cycle representing the mid-luteal phase and luteolysis. Real-time PCR and Western blot analysis were performed to examine the expression of porcine AQP1 and AQP5. Their expression in the uterine explants was also evaluated by immunohistochemistry. The results indicated that uterine expression of AQP1 and AQP5 potentially remains under control of steroid hormones and AA-derived compounds (e.g. prostaglandins). P4, E2, AA, FSK and cAMP cause translocation of AQP5 from apical to the basolateral plasma membrane of the epithelial cells, which might affect the transcellular water movement (through epithelial cells) between uterine lumen and blood vessels. The AC/cAMP pathway is involved in the intracellular signals transduction connected with the regulation of AQPs expression in the pig uterus. This study documented specific patterns of AQP1 and AQP5 expression in response to P4, E2, AA, FSK and cAMP, thereby providing new indirect evidence of their role in maintaining the

  15. Bile acid flux is necessary for normal liver regeneration.

    Directory of Open Access Journals (Sweden)

    Willscott E Naugler

    Full Text Available BACKGROUND & AIMS: Many signals governing liver regeneration (LR following 2/3 partial hepatectomy (PH are recognized, but the primary signal(s remains unknown. The aim of the study was to confirm that the remnant liver after PH lacks capacity to secrete the BA pool returning via the enterohepatic ciruculation (EHC, which may in turn stimulate LR. METHODS: After standard PH, BA flux was documented and BA signaling (Fgf15 and synthesis (Cyp7a determined by qPCR. Rat biliary fistula (BF and Asbt knockout mouse models interrupted the EHC prior to PH, and standard assays for LR employed along with complete RNA sequencing. CCl4 intoxication after BF tested the hypothesis in an alternate injury model. RESULTS: BA rise in systemic blood immediately following PH, confirming that the remnant liver cannot handle the BA returning via portal circulation. When the BA pool is drained prior to PH in the rat BF model, LR is markedly attenuated, a phenomenon reversed with duodenal BA replacement. Hepatocyte proliferation is similarly attenuated after PH in the Asbt knockout mouse as well as after CCl44 intoxication in rats with BF. Complete RNA sequencing in the rat PH model shows that early c-jun and AP-1 gene expression pathways are down regulated in the absence of BA, coincident with attenuated LR. CONCLUSIONS: Absent BA return to the liver after PH or CCl4 injury markedly attenuates LR, though hepatocyte proliferation still occurs, inferring that BA flux and signaling are not the sole signals governing LR. Transcriptional networks involving c-jun and AP-1 are involved in the BA-specific effects on hepatocyte proliferation.

  16. Metabolic flux analysis of Escherichia coli MG1655 under octanoic acid (C8) stress.

    Science.gov (United States)

    Fu, Yanfen; Yoon, Jong Moon; Jarboe, Laura; Shanks, Jacqueline V

    2015-05-01

    Systems metabolic engineering has made the renewable production of industrial chemicals a feasible alternative to modern operations. One major example of a renewable process is the production of carboxylic acids, such as octanoic acid (C8), from Escherichia coli, engineered to express thioesterase enzymes. C8, however, is toxic to E. coli above a certain concentration, which limits the final titer. (13)C metabolic flux analysis of E. coli was performed for both C8 stress and control conditions using NMR2Flux with isotopomer balancing. A mixture of labeled and unlabeled glucose was used as the sole carbon source for bacterial growth for (13)C flux analysis. By comparing the metabolic flux maps of the control condition and C8 stress condition, pathways that were altered under the stress condition were identified. C8 stress was found to reduce carbon flux in several pathways: the tricarboxylic acid (TCA) cycle, the CO2 production, and the pyruvate dehydrogenase pathway. Meanwhile, a few pathways became more active: the pyruvate oxidative pathway, and the extracellular acetate production. These results were statistically significant for three biological replicates between the control condition and C8 stress. As a working hypothesis, the following causes are proposed to be the main causes for growth inhibition and flux alteration for a cell under stress: membrane disruption, low activity of electron transport chain, and the activation of the pyruvate dehydrogenase regulator (PdhR).

  17. Research on flux decline in nanofiltration of lactic acid solutions with ZRIV/PAA membranes application

    Directory of Open Access Journals (Sweden)

    Połom Ewa

    2016-09-01

    Full Text Available The efficiency of lactic acid solutions nanofiltration with dynamically formed zirconium (IV hydrous oxide polyacrylate (ZrIV/PAA membranes application were considered in this paper. The results of investigations on flux decline in nanofiltration of lactic acid solutions under conditions resulting in low and high lactic acid rejection are reported. In the long term experimental research on pressure driven membrane processes the main reason of permeate flux reduction is an accumulation of concentration polarization and fouling effects. The experimental permeate flux versus time curves were analyzed in the frame of resistance-in-series model with the aim to develop the characteristic fouling and concentration polarization resistances. The analysis of experimental data and results of calculations showed that both: concentration polarization and fouling phenomena in investigated system depend on hydrodynamic conditions and properties of filtered solutions and (ZrIV/PAA membrane.

  18. Effect of source on net portal flux of glucose, lactate, volatile fatty acids and amino acids in the pig

    NARCIS (Netherlands)

    Meulen, van der J.; Bakker, J.G.M.; Smits, B.; Visser, de H.

    1997-01-01

    The ileal digestibilities of maize starch and native pea starch do not differ. However maize starch is digested faster than pea starch and the ileal amino acid digestibility of a diet containing pea starch is lower. In the present study, the net portal fluxes of glucose, lactate, volatile fatty

  19. High Upward Fluxes of Formic Acid from a Boreal Forest Canopy

    Science.gov (United States)

    Schobesberger, S.; Lopez-Hilfiker, F.; Taipale, D.; Millet, D. B.; D'Ambro, E.; Mammarella, I.; Zhou, P.; Wolfe, G.; Lee, B. H.; Boy, M.; Thornton, J. A.

    2016-12-01

    Formic acid, HCOOH, is one of the most abundant carboxylic acids found in the atmosphere, affecting cloud chemistry and acidity, and as a common product in the oxidative processing of volatile organic compounds (VOC), it provides constraints on the importance of various pathways and precursors. Yet, significant uncertainties in the sources and sinks of HCOOH concentrations remain. We present measurements of HCOOH mixing ratios and eddy fluxes over a boreal forest canopy in spring/summer. Boreal forests have been identified as a key region for much of the global production of HCOOH, as well as for our lack of understanding of the underlying processes. To our knowledge, these are the first direct measurements of HCOOH exchange above a boreal forest ecosystem. The measured HCOOH fluxes were bidirectional, but mostly upward during daytime, in contrast to studies made elsewhere that reported mostly downward fluxes. Episodes of downward flux were explained well by standard resistor models of dry deposition. The sum of net observed flux and modeled deposition yields an upward "gross flux" of HCOOH, which could not be quantitatively explained by literature estimates of direct vegetative/soil emissions nor by efficient chemical production from other VOC (e.g. monoterpenes). These observations suggest greatly underestimated HCOOH sources, by up to a factor of 10, of biogenic origin in the boreal forest. We implemented a vegetative HCOOH source into the GEOS-Chem chemical transport model to match our derived gross flux, and evaluated the updated model against air- and space-borne HCOOH observations. Model biases in the boundary layer were substantially reduced based on this revised treatment, suggesting that a significant fraction of the missing HCOOH source in boreal regions is located within or just above the forest canopy. Biases in the free troposphere remain unexplained.

  20. Reliable Metabolic Flux Estimation in Escherichia coli Central Carbon Metabolism Using Intracellular Free Amino Acids

    Directory of Open Access Journals (Sweden)

    Nobuyuki Okahashi

    2014-05-01

    Full Text Available 13C metabolic flux analysis (MFA is a tool of metabolic engineering for investigation of in vivo flux distribution. A direct 13C enrichment analysis of intracellular free amino acids (FAAs is expected to reduce time for labeling experiments of the MFA. Measurable FAAs should, however, vary among the MFA experiments since the pool sizes of intracellular free metabolites depend on cellular metabolic conditions. In this study, minimal 13C enrichment data of FAAs was investigated to perform the FAAs-based MFA. An examination of a continuous culture of Escherichia coli using 13C-labeled glucose showed that the time required to reach an isotopically steady state for FAAs is rather faster than that for conventional method using proteinogenic amino acids (PAAs. Considering 95% confidence intervals, it was found that the metabolic flux distribution estimated using FAAs has a similar reliability to that of the PAAs-based method. The comparative analysis identified glutamate, aspartate, alanine and phenylalanine as the common amino acids observed in E. coli under different culture conditions. The results of MFA also demonstrated that the 13C enrichment data of the four amino acids is required for a reliable analysis of the flux distribution.

  1. Perinatal changes in myocardial supply and flux of fatty acids, carbohydrates, and ketone bodies in lambs

    NARCIS (Netherlands)

    Bartelds, B; Gratama, JWC; Knoester, H; Takens, J; Smid, GB; Aarnoudse, JG; Heymans, HSA; Kuipers, JRG

    1998-01-01

    No information is available on perinatal changes in myocardial metabolism in vivo. We measured myocardial supply and flux of fatty acids, carbohydrates, and ketone bodies in chronically instrumented fetal, newborn (1-4 days), and juvenile (7 wk) lambs, by measuring aorta-coronary sinus concentration

  2. C20∶4和C22∶6对早产儿视功能和认知功能的影响%Effects of Docosahexaenoic and Arachidonic Acid on Visual and Cognitive Function of Premature Infants

    Institute of Scientific and Technical Information of China (English)

    韩宏裕; 苏宜香

    2001-01-01

    【目的】 探讨补充模拟母乳二十二碳六烯酸(C22∶6 ,DHA)和二十碳四烯酸(C20∶4,AA)水平的脂肪酸对早产儿视功能和认知功能的影响 。【方法】 选取体质量<2 100 g ,胎龄<37周的早产儿32名,分为3组:A组,母乳组11例;B组,传统配方组10例;C组,补 充组11例。B组配方不含DHA和AA,C组配方添加了DHA和AA。补充组配方补充至婴儿体质量达 (2.50±0.10) kg。当胎龄满42周±1周时以鲍秀兰等新生儿行为神经测定方法测认知功能 ;出生后3个月时测双眼视网膜电图。【结果】 补充组早产儿在视功能、认知功能等方面都 与母乳组相近,而传统配方组则低于母乳组和补充组(P<0.05)。【结论】 给予早产儿 补充模拟母乳水平的DHA和AA,可促进其正常的脑发育和视网膜发育,使认知功能和视功能 与母乳喂养的早产儿相近。%【Objective】 To study the effects of docosahexaenoic ac id (DHA) and arachidonic acid (AA) intake on the visual and cognitive function o f preterm infants. 【Methods】 32 preterm infants (gestational age<37 weeks) wer e divided into three groups which were fed with different formula respectively: group A, breast milk(n=11); group B, a conventional formula lacking DHA and AA (n=10); group C, DHA and AA enriched formula (n=11). Group C was stop ped to fed enriched formula when infant's weight reached (2.50±0.10) kg. Cognitiv e function was evaluated by NBNA test when the corrected age of each preterm inf ant was 42 week±7 day, ERG of both eyes was tested at three-months old. The ex periment lasted for three months. 【Results】 Cognitive and visual function of g roup C were similar to group A, however, some indexes of group B were significan tly lower than group A and C (P<0.05). 【Conclusion】 Adding DHA and AA to f ormulas similar to breast milk in amounts, can improve cognitive and visual func tion of preterm infants, and help these infants

  3. Carbon fluxes in an acid rain impacted boreal headwater catchment

    Science.gov (United States)

    Marx, Anne; Hintze, Simone; Jankovec, Jakub; Sanda, Martin; Dusek, Jaromir; Vogel, Tomas; van Geldern, Robert; Barth, Johannes A. C.

    2016-04-01

    Terrestrial carbon export via inland aquatic systems is a key process in the budget of the global carbon cycle. This includes loss of carbon to the atmosphere via gas evasion from rivers or reservoirs as well as carbon fixation in freshwater sediments. Headwater streams are the first endmembers of the transition of carbon between soils, groundwater and surface waters and the atmosphere. In order to quantify these processes the experimental catchment Uhlirska (1.78 km2) located in the northern Czech Republic was studied. Dissolved inorganic, dissolved organic and particulate organic carbon (DIC, DOC, POC) concentrations and isotopes were analyzed in ground-, soil -and stream waters between 2014 and 2015. In addition, carbon dioxide degassing was quantified via a stable isotope modelling approach. Results show a discharge-weighted total carbon export of 31.99 g C m-2 yr-1 of which CO2 degassing accounts 79 %. Carbon isotope ratios (δ13C) of DIC, DOC, and POC (in ‰ VPDB) ranged from -26.6 to -12.4 ‰ from -29.4 to -22.7 ‰ and from -30.6 to -26.6 ‰ respectively. The mean values for DIC are -21.8 ±3.8 ‰ -23.6 ±0.9 ‰ and -19.5 ±3.0 ‰ for soil, shallow ground and surface water compartments. For DOC, these compartments have mean values of -27.1 ±0.3 ‰ -27.0 ±0.8 ‰ and -27.4 ±0.7 ‰Ṁean POC value of shallow groundwaters and surface waters are -28.8 ±0.8 ‰ and -29.3 ±0.5 ‰ respectively. These isotope ranges indicate little turnover of organic material and predominant silicate weathering. The degassing of CO2 caused an enrichment of the δ13C-DIC values of up to 6.8 ‰ between a catchment gauge and the catchment outlet over a distance of 866 m. In addition, the Uhlirska catchment has only negligible natural sources of sulphate, yet SO42- accounts for 21 % of major stream water ions. This is most likely a remainder from acid rain impacts in the area.

  4. Combining rational metabolic engineering and flux optimization strategies for efficient production of fumaric acid.

    Science.gov (United States)

    Song, Chan Woo; Lee, Sang Yup

    2015-10-01

    Fumaric acid is an important C4-dicarboxylic acid widely used in chemical, food, and pharmaceutical industries. Rational metabolic engineering together with flux optimization were performed for the development of an Escherichia coli strain capable of efficiently producing fumaric acid. The initial engineered strain, CWF4N overexpressing phosphoenolpyruvate carboxylase (PPC), produced 5.30 g/L of fumaric acid. Optimization of PPC flux by examining 24 types of synthetic PPC expression vectors further increased the titer up to 5.72 g/L with a yield of 0.432 g/g·glucose. Overexpression of the succinate dehydrogenase complex (sdhCDAB) led to an increase in carbon yield up to 0.493 g/g·glucose. Based on this mutant strain, citrate synthase (CS) was combinatorially overexpressed and balanced with PPC using 48 types of synthetic expression vectors. As a result, 6.24 g/L of fumaric acid was produced with a yield of 0.500 g/g·glucose. Fed-batch culture of this final strain allowed production of 25.5 g/L of fumaric acid with a yield of 0.366 g/g·glucose. Deletion of the aspA gene encoding aspartase and supplementation of aspartic acid further increased the fumaric acid titer to 35.1 g/L with a yield of 0.490 g/g·glucose.

  5. Laboratory Study of Methane Flux from Acid Sulphate Soil in South Kalimantan

    Science.gov (United States)

    Annisa, W.; Cahyana, D.; Syahbuddin, H.; Rachman, A.

    2017-06-01

    Addition of organic matter in waterlogged conditions will enhance methanogenesis process that produces greenhouse gases. Fresh organic material is considered reactive because it contains carbons that is subject to decompose, therefore, when it exposed to acid sulphate soil, both in natural condition (aeration required) and intensive (aeration not required) will lower the value of redox potential. This experiment aimed to determine the flux of methane (CH4) from various locally available organic materials applied to acid sulphate soil. The experiment was arranged in factorial design with two factors. The first factor was the source of organic matter, i.e. fresh rice straw, fresh purun, fresh cattle manure, composted rice straw, composted purun and composted cattle manure, and control. The second factor was the management of organic matter i.e. placed on the soil surface with no tillage and mixed with soil during tillage. The results showed that application of fresh organic matter into inundated acid sulphate soil increased CH4 fluxes up to 23.78 µg CH4 g1 d1 which was higher than from composted organic matter (4.327 µg CH4.g1.d1). Methane flux due to organic matter management was significantly negatively (p=0.001) correlated with soil redox potential (Eh) with R2 of - 0.76. Organic matter placed on the soil surface with no tillage produced methane flux ranged from 0.33 to 20.78 g CH4 g1 d1, which was lower than methane flux produced from organic matter mixed with soil during tillage (0.38 to 27.27 g CH4 g1 d1). Composting organic matter before application and mixing them with the soil through tillage are highly recommended to reduce greenhouse gas emissions from cultivated acid sulphate soils.

  6. Domestication of the high-sugar-tolerant Mortierella alpina on arachidonic acid (ARA) production%花生四烯酸产生菌高山被孢霉的高糖驯化研究

    Institute of Scientific and Technical Information of China (English)

    曾思钰; 凌雪萍; 张长杰; 卢英华

    2012-01-01

    [目的]提高花生四烯酸(Arachidonic acid,ARA)产量,克服ARA产生菌高山被孢霉(Mortierella alpina)在长期的保存及使用过程中易受到外界条件影响发生退化,从而导致菌种耗糖量降低、影响菌种摄入营养的能力和不利于工业化生产的缺点.[方法]首先采用固体培养基驯化,将菌种逐级涂布于梯度高糖PDA平板(含糖量分别为2%、5%、7%、10%和15%)培养,挑选经固体驯化后能耐受10%高糖浓度平板的菌种,转接到两种含不同氮源的梯度高糖(含糖量分别为3%、4%、5%和6%)液体培养基中进行驯化,最后对驯化后的菌种进行2L发酵罐放大实验.[结果]当培养基中以酵母粉为氮源时,驯化后菌体的最高耗糖量由3 g/(L·d)提高到12 g/(L·d);当培养基中以玉米浆为氮源时,驯化后菌体的最高耗糖量由7 g/(L·d)提高到12 g/(L·d).摇瓶驯化实验结果表明以玉米浆为氮源驯化的菌种发酵效果较好,发酵罐实验结果显示菌体生物量为50 g/L,总油脂为18 g/L,目的产物ARA产量为8g/L.相比未驯化之前的发酵结果,生物量和总油脂含量提高了近3倍,ARA产量提高了近4倍.[结论]经过高糖驯化,菌种的耗糖能力得到提高,生物量、总油脂及ARA的产量也都有所增加,从而可以使菌种在保存和使用过程中不易退化,保持稳定.%[Objective] In order to improve arachidonia acid (ARA) production, and prevent the degeneration of ARA-producing strain Mortierella alpina in long-term culture preservation and cultivation, which could lead to low consumption rate of substrates like carbon source. [Methods] Mortierella alpina strain was first domesticated in high-sugar PDA plate with gradient sugar content (2%, 5%, 7%, 10% and 15%). The strain which grew better in the solid medium containing 10% sugar was then selected and transferred to two liquid high-sugar media with different nitrogen sources to domesticate. The gradient sugar

  7. Competition for amino acid flux among translation, growth and detoxification in bacteria.

    Science.gov (United States)

    Ferro, Iolanda; Chelysheva, Irina; Ignatova, Zoya

    2017-03-15

    Transfer RNAs (tRNAs) are central entities for translation that deliver amino acids to the ribosome to translate genetic information in an mRNA-template dependent manner. Recent discoveries from our laboratory show that in E. coli and B. licheniformis, some tRNAs are poorly charged despite the plentiful intracellular cognate amino acid. Specifically, tRNAs carrying amino acids that exert toxicity and inhibit bacterial growth when added separately to the growth medium are poorly charged. Here, we discuss various evolutionary strategies different bacterial cells have adopted to precisely hone the competition between amino acid utilization for translation and proliferation and combat the inhibitory effect towards maximizing bacterial fitness. These data add a new twist to the amino acid flux models and to our understanding of the complex intimate link between dynamics of translation and bacterial growth.

  8. Seasonal measurements of organic acid fluxes over a ponderosa pine forest

    Science.gov (United States)

    Fulgham, S. R.; Brophy, P.; Link, M.; Ortega, J. V.; Farmer, D.

    2016-12-01

    The biosphere acts as both a source and a sink of oxidized organic compounds. Ignoring dry deposition leads to overestimation of secondary organic aerosols by aerosol models, while ignoring emission sources underestimates the budget of organic acids. Developing parameterizations for oxidized organic dry deposition and emission requires observational constraints. Although biosphere parameters are impacted by seasonal variability, most reactive, trace-gas exchange measurements are made for only short periods of time in the main growing season. Here we make fast (5 - 10 Hz) and sensitive (e.g. 0.73 ppt mean limit of detection for formic acid with 10 s averaging) eddy covariance measurements of gas-phase organic acids and other oxidized organic species with a high resolution Time-of-Flight Chemical Ionization Mass Spectrometer with acetate and iodide reagent ions. Measurements were made in 4 - 6 week campaigns over five seasons from summer 2015 to fall 2016 as part of the Seasonal Particles in Forests Flux studY (SPIFFY) at the Manitou Experimental Forest Observatory near Woodland Park, Colorado. Permeation tubes were used for online calibration of carboxylic acids including formic (C1), propionic (C3), butyric (C4), methacrylic (CH2C(CH3)COOH), valeric (C5), and heptanoic (C7) acids. Average daytime mixing ratios for formic acid were 100 ± 100 ppt in winter and 1500 ± 1000 ppt in summer 2016. Upward fluxes of formic acid were observed throughout the experiment, daytime averages and standard deviations ranging from 1900 ± 1000 ppt cm s-1 in winter to 170 ± 130 ppt cm s-1 in spring. Propionic (22 ± 22 ppt cm s-1), butyric (17 ± 16 ppt cm s-1), and methacrylic (3.5 ± 6.1 ppt cm s-1) acids exhibit a mix of upward, near-zero, and downward fluxes. Fluxes were exponentially correlated to temperature, suggesting an ecosystem-scale source of these acids. We also measure exchange velocities of a broad suite of other oxidized organic compounds (31.99 m/z to 311.523 m/z in

  9. Oxidation of esterified arachidonate by rat liver microsomes

    Energy Technology Data Exchange (ETDEWEB)

    Davis, H.W.; Suzuki, T.; Schenkman, J.B.

    1986-03-05

    The authors have previously demonstrated a relationship between phospholipid arachidonate in liver microsomes and malondialdehyde (MDA) formation during lipid peroxidation. In this study arachidonic acid (U-/sup 14/C) was incorporated into rat liver microsomes and NADPH-supported peroxidation was carried out at 37/sup 0/C for 15 minutes. The microsomes were pelleted by centrifugation and the labeled products in the supernatant were isolated by a solid phase method. Pellets were hydrolyzed with phospholipase A/sub 2/ and extracted with diethyl ether and the products from both fractions were separated by reverse phase HPLC. The results show that (1) oxidation occurs in all of the major phospholipids but that phosphatidylethanolamine is the most susceptible; (2) a linear correlation exists between MDA formation and supernatant radioactivity; (3) several different polar products are found in both the supernatant and the hydrolyzed pellet but that the ratios of product peaks in HPLC do not change during the peroxidation, indicating no secondary metabolism or propagation; and (4) cytochrome P-450 is not involved in the peroxidative reactions since no oxidation occurs in the absence of Fe/sup 3 +/ and since product formation is unaffected in the presence of carbon monoxide.

  10. Milk in the island of Chole [Tanzania] is high in lauric, myristic, arachidonic and docosahexaenoic acids, and low in linoleic acid - Reconstructed diet of infants born to our ancestors living in tropical coastal regions

    NARCIS (Netherlands)

    Kuipers, Remko S.; Smit, Ella N.; van der Meulen, Jan; Dijck-Brouwer, D. A. Janneke; Boersma, E. Rudy; Muskiet, Frits A. J.

    2007-01-01

    Background: We need information on the diet on which our genes evolved. Objective: We studied the milk fatty acid [FA] composition of mothers living in the island of Chole [Tanzania, Indian Ocean]. These mothers have high intakes of boiled marine fish and coconut, and consume plenty amount of fruits

  11. A relaxed eddy accumulation system for measuring vertical fluxes of nitrous acid

    Directory of Open Access Journals (Sweden)

    X. Ren

    2011-10-01

    Full Text Available A relaxed eddy accumulation (REA system combined with a nitrous acid (HONO analyzer was developed to measure atmospheric HONO vertical fluxes. The system consists of three major components: (1 a fast-response sonic anemometer measuring both vertical wind velocity and air temperature, (2 a fast-response controlling unit separating air motions into updraft and downdraft samplers by the sign of vertical wind velocity, and (3 a highly sensitive HONO analyzer based on aqueous long path absorption photometry that measures HONO concentrations in the updrafts and downdrafts. A dynamic velocity threshold (±0.5σw, where σw is a standard deviation of the vertical wind velocity was used for valve switching determined by the running means and standard deviations of the vertical wind velocity. Using measured temperature as a tracer and the average values from two field deployments, the flux proportionality coefficient, β, was determined to be 0.42 ± 0.02, in good agreement with the theoretical estimation. The REA system was deployed in two ground-based field studies. In the California Research at the Nexus of Air Quality and Climate Change (CalNex study in Bakersfield, California in summer 2010, measured HONO fluxes appeared to be upward during the day and were close to zero at night. The upward HONO flux was highly correlated to the product of NO2 and solar radiation. During the Biosphere Effects on Aerosols and Photochemistry Experiment (BEARPEX 2009 at Blodgett Forest, California in July 2009, the overall HONO fluxes were small in magnitude and were close to zero. Causes for the different HONO fluxes in the two different environments are briefly discussed.

  12. Optimization of Mortierella Isabellina culture medium conditions in fermentation of arachidonic acid by response surface methodology%响应面法优化深黄被孢霉发酵生产花生四烯酸的培养基条件

    Institute of Scientific and Technical Information of China (English)

    于新新; 于长青

    2013-01-01

    为了降低深黄被孢霉YZ-124生产花生四烯酸的成本,研究了不同添加量的玉米黄浆水对发酵的影响,与葡萄糖培养基相比,在发酵培养基中添加一定量的玉米黄浆水对发酵产量无显著影响.在单因素实验的基础上,利用Design Expert设计了响应面实验,研究了葡萄糖浓度、不同添加量的玉米黄浆水和初始pH对花生四烯酸产量的影响.结果表明,最佳的培养基条件是葡萄糖浓度为90g/L、添加体积分数为25%的玉米黄浆水、初始pH6时,花生四烯酸(ARA)产量达到最大,为3.11g/L.%Fermentative production arachidonic acid of Mortierella isabellina using waste water from maize paste was investigated to reduce the cost,adding waste water from maize paste into the culture medium had no obvious effect on the fermentation. On the basis of single factor tests .response surface analysis was designed by Design Expert,and the glucose concentration,different quality of waste water from maize paste and pH were investigated. The results showed that the optimal culture medium conditions were the glucose concentration was 90g/L,the maize paste waste water was 25% in the culture medium and pH was 6. Under this condition,the yield of arachidonic acid was 3.11g/L.

  13. Phosphorus limitation strategy to increase propionic acid flux towards 3-hydroxyvaleric acid monomers in Cupriavidus necator.

    Science.gov (United States)

    Grousseau, Estelle; Blanchet, Elise; Déléris, Stéphane; Albuquerque, Maria G E; Paul, Etienne; Uribelarrea, Jean-Louis

    2014-02-01

    Properties of polyhydroxybutyrate-co-hydroxyvalerate (P(3HB-co-3HV)) depend on their 3HV content. 3HV can be produced by Cupriavidus necator from propionic acid. Few studies explored carbon distribution and dynamics of 3HV and 3HB monomers production, and none of them have been done with phosphorus as limiting nutrient. In this study, fed-batch cultures of C. necator with propionic acid, as sole carbon source or mixed with butyric acid, were performed. Phosphorus deficiency allowed sustaining 3HV production rate and decreasing 3HB production rate, leading to an instant production of up to 100% of 3HV. When a residual growth is sustained by a phosphorus feeding, the maximum 3HV percentage produced from propionic acid is limited to 33% (Mole.Mole(-1)). The association of a second carbon source like butyric acid lead to higher conversion of propionic acid into 3HV. This study showed the importance of the limiting nutrient and of the culture strategy to get the appropriate product. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Central metabolic responses to the overproduction of fatty acids in Escherichia coli based on 13C-metabolic flux analysis.

    Science.gov (United States)

    He, Lian; Xiao, Yi; Gebreselassie, Nikodimos; Zhang, Fuzhong; Antoniewiez, Maciek R; Tang, Yinjie J; Peng, Lifeng

    2014-03-01

    We engineered a fatty acid overproducing Escherichia coli strain through overexpressing tesA (“pull”) and fadR (“push”) and knocking out fadE (“block”). This “pull-push-block” strategy yielded 0.17 g of fatty acids (C12–C18) per gram of glucose (equivalent to 48% of the maximum theoretical yield) in batch cultures during the exponential growth phase under aerobic conditions. Metabolic fluxes were determined for the engineered E. coli and its control strain using tracer ([1,2-13C]glucose) experiments and 13C-metabolic flux analysis. Cofactor (NADPH) and energy (ATP) balances were also investigated for both strains based on estimated fluxes. Compared to the control strain, fatty acid overproduction led to significant metabolic responses in the central metabolism: (1) Acetic acid secretion flux decreased 10-fold; (2) Pentose phosphate pathway and Entner–Doudoroff pathway fluxes increased 1.5- and 2.0-fold, respectively; (3) Biomass synthesis flux was reduced 1.9-fold; (4) Anaplerotic phosphoenolpyruvate carboxylation flux decreased 1.7-fold; (5) Transhydrogenation flux converting NADH to NADPH increased by 1.7-fold. Real-time quantitative RT-PCR analysis revealed the engineered strain increased the transcription levels of pntA (encoding the membrane-bound transhydrogenase) by 2.1-fold and udhA (encoding the soluble transhydrogenase) by 1.4-fold, which is in agreement with the increased transhydrogenation flux. Cofactor and energy balances analyses showed that the fatty acid overproducing E. coli consumed significantly higher cellular maintenance energy than the control strain. We discussed the strategies to future strain development and process improvements for fatty acid production in E. coli.

  15. Improvement of glucaric acid production in E. coli via dynamic control of metabolic fluxes

    Directory of Open Access Journals (Sweden)

    Irene M. Brockman Reizman

    2015-12-01

    Full Text Available D-glucaric acid can be used as a building block for biopolymers as well as in the formulation of detergents and corrosion inhibitors. A biosynthetic route for production in Escherichia coli has been developed (Moon et al., 2009, but previous work with the glucaric acid pathway has indicated that competition with endogenous metabolism may limit carbon flux into the pathway. Our group has recently developed an E. coli strain where phosphofructokinase (Pfk activity can be dynamically controlled and demonstrated its use for improving yields and titers of the glucaric acid precursor myo-inositol on glucose minimal medium. In this work, we have explored the further applicability of this strain for glucaric acid production in a supplemented medium more relevant for scale-up studies, both under batch conditions and with glucose feeding via in situ enzymatic starch hydrolysis. It was found that glucaric acid titers could be improved by up to 42% with appropriately timed knockdown of Pfk activity during glucose feeding. The glucose feeding protocol could also be used for reduction of acetate production in the wild type and modified E. coli strains.

  16. Regulation of amino-acid metabolism controls flux to lipid accumulation in Yarrowia lipolytica

    DEFF Research Database (Denmark)

    Kerkhoven, Eduard J.; Pomraning, Kyle R.; Baker, Scott E.

    2016-01-01

    cultures. We first reconstructed a genome-scale metabolic model and used this for integrative analysis of multilevel omics data. Metabolite profiling and lipidomics was used to quantify the cellular physiology, while regulatory changes were measured using RNAseq. Analysis of the data showed that lipid......Yarrowia lipolytica is a promising microbial cell factory for the production of lipids to be used as fuels and chemicals, but there are few studies on regulation of its metabolism. Here we performed the first integrated data analysis of Y. lipolytica grown in carbon and nitrogen limited chemostat...... accumulation in Y. lipolytica does not involve transcriptional regulation of lipid metabolism but is associated with regulation of amino-acid biosynthesis, resulting in redirection of carbon flux during nitrogen limitation from amino acids to lipids. Lipid accumulation in Y. lipolytica at nitrogen limitation...

  17. Synthesis and regulation of chlorogenic acid in potato: Rerouting phenylpropanoid flux in HQT-silenced lines.

    Science.gov (United States)

    Payyavula, Raja S; Shakya, Roshani; Sengoda, Venkatesan G; Munyaneza, Joseph E; Swamy, Prashant; Navarre, Duroy A

    2015-05-01

    Chlorogenic acid (CGA) is the major phenolic sink in potato tubers and can constitute over 90% of total phenylpropanoids. The regulation of CGA biosynthesis in potato and the role of the CGA biosynthetic gene hydroxycinnamoyl CoA:quinate hydroxycinnamoyl transferase (HQT) was characterized. A sucrose induced accumulation of CGA correlated with the increased expression of phenylalanine ammonia-lyase (PAL) rather than HQT. Transient expression of the potato MYB transcription factor StAN1 (anthocyanin 1) in tobacco increased CGA. RNAi suppression of HQT resulted in over a 90% reduction in CGA and resulted in early flowering. The reduction in total phenolics and antioxidant capacity was less than the reduction in CGA, suggesting flux was rerouted into other phenylpropanoids. Network analysis showed distinct patterns in different organs, with anthocyanins and phenolic acids showing negative correlations in leaves and flowers and positive in tubers. Some flavonols increased in flowers, but not in leaves or tubers. Anthocyanins increased in flowers and showed a trend to increase in leaves, but not tubers. HQT suppression increased biosynthesis of caffeoyl polyamines, some of which are not previously reported in potato. Decreased PAL expression and enzyme activity was observed in HQT suppressed lines, suggesting the existence of a regulatory loop between CGA and PAL. Electrophysiology detected no effect of CGA suppression on potato psyllid feeding. Collectively, this research showed that CGA in potatoes is synthesized through HQT and HQT suppression altered phenotype and redirected phenylpropanoid flux.

  18. Subchronic (13-week) oral toxicity study, preceded by an in utero exposure phase, with arachidonate-enriched triglyceride oil (SUNTGA40S) in rats

    NARCIS (Netherlands)

    Lina, B.A.R.; Wolterbeek, A.P.M.; Suwa, Y.; Fujikawa, S.; Ishikura, Y.; Tsuda, S.; Dohnalek, M.

    2006-01-01

    Polyunsaturated fatty acids (PUFAs), such as arachidonic acid (ARA) and docosahexaenoic acid (DHA) are natural constituents found in human milk, fish oil or egg yolk. Until recently, infant formulas, though providing the essential fatty acid precursors for these PUFAs, did not contain preformed ARA

  19. Subchronic (13-week) oral toxicity study, preceded by an in utero exposure phase, with arachidonate-enriched triglyceride oil (SUNTGA40S) in rats

    NARCIS (Netherlands)

    Lina, B.A.R.; Wolterbeek, A.P.M.; Suwa, Y.; Fujikawa, S.; Ishikura, Y.; Tsuda, S.; Dohnalek, M.

    2006-01-01

    Polyunsaturated fatty acids (PUFAs), such as arachidonic acid (ARA) and docosahexaenoic acid (DHA) are natural constituents found in human milk, fish oil or egg yolk. Until recently, infant formulas, though providing the essential fatty acid precursors for these PUFAs, did not contain preformed ARA

  20. Effects of α-linolenic acid and arachidonic acid on the expressions of nuclear transcription factor Nrf 2 and phase Ⅰ metabolism enzyme CYP7A1%α-亚麻酸和花生四烯酸对Nrf2和Ⅰ相代谢酶CYP7A1表达的影响

    Institute of Scientific and Technical Information of China (English)

    张金铭; 张秀英; 郝丽红; 马丽梅

    2016-01-01

    为了检测α-亚麻酸(α-linolenic acid,ALA)和花生四烯酸(arachidonic acid,AA)对于人肝癌细胞系(HepG2细胞)中核转录因子Nrf 2和Ⅰ相代谢酶胆固醇7α-羟化酶(CYP7A1)的mRNA和蛋白质表达的影响,并探究CYP7A1是否受Nrf2的调控,试验以不同浓度的ALA和AA诱导HepG2细胞24 h,之后采用Real-time PCR法和Western-blot法分别检测HepG2细胞内Nrf 2和CYP7A1的mRNA和蛋白质的表达量.结果表明:当使ALA浓度为0.25,0.5,1 mmol/L作用于HepG2细胞时,Nrf2和CYP7A1的mRNA和蛋白质的表达量相比于细胞对照均呈剂量依赖性升高(P<0.01);当使AA浓度为0.25,0.5,1 mmol/L作用于HepG2细胞时,Nrf 2的mRNA和蛋白质的表达量相比于细胞对照呈剂量依赖性升高(P<0.01),但CYP7A1的mRNA和蛋白质的表达量相比于细胞对照则呈剂量依赖性减少(P<0.01).说明不同剂量的ALA和AA对Nrf 2和CYP7A1的mRNA和蛋白质的表达量影响不同,Nrf 2和CYP7A1呈正相关或负相关.

  1. (13)C Metabolic Flux Analysis for Systematic Metabolic Engineering of S. cerevisiae for Overproduction of Fatty Acids.

    Science.gov (United States)

    Ghosh, Amit; Ando, David; Gin, Jennifer; Runguphan, Weerawat; Denby, Charles; Wang, George; Baidoo, Edward E K; Shymansky, Chris; Keasling, Jay D; García Martín, Héctor

    2016-01-01

    Efficient redirection of microbial metabolism into the abundant production of desired bioproducts remains non-trivial. Here, we used flux-based modeling approaches to improve yields of fatty acids in Saccharomyces cerevisiae. We combined (13)C labeling data with comprehensive genome-scale models to shed light onto microbial metabolism and improve metabolic engineering efforts. We concentrated on studying the balance of acetyl-CoA, a precursor metabolite for the biosynthesis of fatty acids. A genome-wide acetyl-CoA balance study showed ATP citrate lyase from Yarrowia lipolytica as a robust source of cytoplasmic acetyl-CoA and malate synthase as a desirable target for downregulation in terms of acetyl-CoA consumption. These genetic modifications were applied to S. cerevisiae WRY2, a strain that is capable of producing 460 mg/L of free fatty acids. With the addition of ATP citrate lyase and downregulation of malate synthase, the engineered strain produced 26% more free fatty acids. Further increases in free fatty acid production of 33% were obtained by knocking out the cytoplasmic glycerol-3-phosphate dehydrogenase, which flux analysis had shown was competing for carbon flux upstream with the carbon flux through the acetyl-CoA production pathway in the cytoplasm. In total, the genetic interventions applied in this work increased fatty acid production by ~70%.

  2. 13C Metabolic Flux Analysis for systematic metabolic engineering of S. cerevisiae for overproduction of fatty acids.

    Directory of Open Access Journals (Sweden)

    Amit Ghosh

    2016-10-01

    Full Text Available Efficient redirection of microbial metabolism into the abundant production of desired bioproducts remains non-trivial. Here we used flux-based modeling approaches to improve yields of fatty acids in S. cerevisiae. We combined 13C labeling data with comprehensive genome-scale models to shed light onto microbial metabolism and improve metabolic engineering efforts. We concentrated on studying the balance of acetyl-CoA, a precursor metabolite for the biosynthesis of fatty acids. A genome-wide acetyl-CoA balance study showed ATP citrate lyase from Y. lipolytica as a robust source of cytoplasmic acetyl-CoA and malate synthase as a desirable target for down-regulation in terms of acetyl-CoA consumption. These genetic modifications were applied to S. cerevisiae WRY2, a strain that is capable of producing 460 mg L of free fatty acids. With the addition of ATP citrate lyase and down-regulation of malate synthase the engineered strain produced 26 per cent more free fatty acids. Further increases in free fatty acid production of 33 per cent were obtained by knocking out the cytoplasmic glycerol-3-phosphate dehydrogenase, which flux analysis had shown was competing for carbon flux upstream with the carbon flux through the acetyl-CoA production pathway in the cytoplasm. In total, the genetic interventions applied in this work increased fatty acid production by 70 per cent.

  3. Acyl-CoA synthetase activity links wild-type but not mutant a-Synuclein to brain arachidonate metabolism

    DEFF Research Database (Denmark)

    Golovko, Mikhail; Rosenberger, Thad; Færgeman, Nils J.

    2006-01-01

    Because alpha-synuclein (Snca) has a role in brain lipid metabolism, we determined the impact that the loss of alpha-synuclein had on brain arachidonic acid (20:4n-6) metabolism in vivo using Snca-/- mice. We measured [1-(14)C]20:4n-6 incorporation and turnover kinetics in brain phospholipids usi...

  4. Sheep erythrocyte membrane binding and transfer of long-chain fatty acids

    DEFF Research Database (Denmark)

    Bojesen, Inge Norby; Bojesen, Eigil

    1999-01-01

    Palmitic acid, oleic acid, linoleic acid, arachidonic acid, sheep erythrocyte ghosts, transporting elements, transport kinetics, fatty acid transport, transport rate constants......Palmitic acid, oleic acid, linoleic acid, arachidonic acid, sheep erythrocyte ghosts, transporting elements, transport kinetics, fatty acid transport, transport rate constants...

  5. Extraction, purification, methylation and GC-MS analysis of short-chain carboxylic acids for metabolic flux analysis.

    Science.gov (United States)

    Tivendale, Nathan D; Jewett, Erin M; Hegeman, Adrian D; Cohen, Jerry D

    2016-08-15

    Dynamic metabolic flux analysis requires efficient and effective methods for extraction, purification and analysis of a plethora of naturally-occurring compounds. One area of metabolism that would be highly informative to study using metabolic flux analysis is the tricarboxylic acid (TCA) cycle, which consists of short-chain carboxylic acids. Here, we describe a newly-developed method for extraction, purification, derivatization and analysis of short-chain carboxylic acids involved in the TCA cycle. The method consists of snap-freezing the plant material, followed by maceration and a 12-15h extraction at -80 °C. The extracts are then subject to reduction (to stabilize β-keto acids), purified by strong anion exchange solid phase extraction and methylated with methanolic HCl. This method could also be readily adapted to quantify many other short-chain carboxylic acids.

  6. Formation of isoprostane bicyclic endoperoxides from the autoxidation of cholesteryl arachidonate.

    Science.gov (United States)

    Yin, Huiyong; Havrilla, Christine M; Morrow, Jason D; Porter, Ned A

    2002-07-03

    Autoxidation of polyunsaturated fatty acids and esters leads to a complex mixture containing hydroperoxides and cyclic peroxides. Prostaglandin bicyclic endoperoxides have been detected from the autoxidation of cholesteryl arachidonate by LC-MS and GC-MS techniques. All four possible types (I-IV) of bicyclic endoperoxides have been found starting from different regioisomeric hydroperoxides of cholesteryl arachidonate. Furthermore, the stereochemistry of Type IV bicyclic endoperoxides has been determined by conversion to pentafluorobenzyl (PFB) ester, trimethylsilyl (TMS) derivatives, and comparison with synthetic standards by the use of GC-MS. All eight possible diastereomers of the derivatized isoprostanes were observed and were separated by gas chromatography. The bicyclic endoperoxides with the two alkyl chains syn on the cyclopentane ring were formed preferentially to those with anti configuration, a result anticipated from earlier work. Substantial amounts of the anti-substituted isoprostanes, including PGF(2)(alpha), were, however, observed in the product mixture.

  7. Systems-level metabolic flux profiling elucidates a complete, bifurcated tricarboxylic acid cycle in Clostridium acetobutylicum.

    Science.gov (United States)

    Amador-Noguez, Daniel; Feng, Xiao-Jiang; Fan, Jing; Roquet, Nathaniel; Rabitz, Herschel; Rabinowitz, Joshua D

    2010-09-01

    Obligatory anaerobic bacteria are major contributors to the overall metabolism of soil and the human gut. The metabolic pathways of these bacteria remain, however, poorly understood. Using isotope tracers, mass spectrometry, and quantitative flux modeling, here we directly map the metabolic pathways of Clostridium acetobutylicum, a soil bacterium whose major fermentation products include the biofuels butanol and hydrogen. While genome annotation suggests the absence of most tricarboxylic acid (TCA) cycle enzymes, our results demonstrate that this bacterium has a complete, albeit bifurcated, TCA cycle; oxaloacetate flows to succinate both through citrate/alpha-ketoglutarate and via malate/fumarate. Our investigations also yielded insights into the pathways utilized for glucose catabolism and amino acid biosynthesis and revealed that the organism's one-carbon metabolism is distinct from that of model microbes, involving reversible pyruvate decarboxylation and the use of pyruvate as the one-carbon donor for biosynthetic reactions. This study represents the first in vivo characterization of the TCA cycle and central metabolism of C. acetobutylicum. Our results establish a role for the full TCA cycle in an obligatory anaerobic organism and demonstrate the importance of complementing genome annotation with isotope tracer studies for determining the metabolic pathways of diverse microbes.

  8. Alternative method for thermal neutron flux measurements based on common boric acid as converter and Lr-15 detectors

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, D.; Greaves, E. D.; Sajo B, L.; Barros, H. [Universidad Simon Bolivar, Laboratorio de Fisica Nuclear, Apdo. Postal 89000, Caracas (Venezuela, Bolivarian Republic of); Ingles, R. [Universidad Nacional de San Antonio Abad del Cusco, Av. de la Cultura No. 733, Cusco (Peru)

    2010-02-15

    A method to determine the flux and angular distribution of thermal neutrons with the use of Lr-115 detectors was developed. The use of the Lr-115 detector involves the exposure of a pressed boric acid sample (tablet) as a target, in tight contact with the track detector, to a flux of thermalized neutrons. The self-absorption effects in thin films or foil type thermal neutron detectors can be neglected by using the Lr-115 detector and boric acid tablet setup to operate via backside irradiation. The energy window and the critical angle-residual energy curve were determined by comparisons between the experimental and simulated track parameters. A computer program was developed to calculate the detector registration efficiency, so that the thermal neutron flux can be calculated from the track densities induced in the Lr-115 detector using the derived empirical formula. The proposed setup can serves as directional detector of thermal neutrons. (Author)

  9. Nitrous-Oxide Flux from Nitric-Acid-Treated Cattle Slurry Applied to Grassland under Semi-Controlled Conditions

    NARCIS (Netherlands)

    Velthof, G.L.; Oenema, O.

    1993-01-01

    Nitrous oxide (N2O) fluxes from cattle slurry after surface application to grassland were measured under semi-controlled environmental conditions during three periods in 1991. Three types of cattle slurry were examined; untreated slurry and slurries treated with nitric acid (HNO3) to pH 6.0 and 4.5.

  10. Post-operative changes in hepatic, intestinal, splenic and muscle fluxes of amino acids and ammonia in pigs.

    Science.gov (United States)

    Deutz, N E; Reijven, P L; Athanasas, G; Soeters, P B

    1992-11-01

    1. After operation, changes in nitrogen metabolism occur. Although increased flux of amino acids from peripheral to splanchnic organs after operation has been described, substrate utilization by the individual organs in the splanchnic area is less well characterized. We were specifically interested in substrate flux across the spleen as it is an organ with important immunological functions. 2. Therefore, hindquarter, gut, spleen and liver fluxes of amino acids, ammonia, glucose, lactate and blood gases were measured for 4 days after a standard operation in pigs. In a separate control group, fluxes were measured 2-3 weeks after this operation and these values were assumed to represent the normal situation. 3. One day after operation, the hindquarter effluxes of glutamine, alanine and several essential amino acids were increased (P > 0.001), but these normalized at the end of the observation period. In the same period, liver glutamine uptake increased (P ammonia production decreased, concomitant with decreased glutamine uptake (P ammonia increased sevenfold (P < 0.05) and that of lactate increased from -158 +/- 544 to 3294 +/- 642 nmol min-1 kg-1 body weight (P < 0.001). Glucose uptake increased from -964 +/- 632 to -3933 +/- 1524 nmol min-1 kg-1 body weight and glutamine efflux (391 +/- 143) reversed to uptake (-752 +/- 169 nmol min-1 kg-1 body weight) (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

  11. BIRM 270: a novel inhibitor of arachidonate release that blocks leukotriene B4 and platelet-activating factor biosynthesis in human neutrophils.

    Science.gov (United States)

    Farina, P R; Graham, A G; Hoffman, A F; Watrous, J M; Borgeat, P; Nadeau, M; Hansen, G; Dinallo, R M; Adams, J; Miao, C K

    1994-12-01

    (S)-N-[2-Cyclohexyl-1-(2-pyridinyl)ethyl]-5-methyl-2-benzoxazolamine+ ++ (BIRM 270) was identified as a potent and enantiomerically selective inhibitor of calcium ionophore A23187-stimulated leukotriene B4 biosynthesis in human neutrophils. The (S)- and (R)-enantiomers exhibited IC50 values of 1 nM and 40 nM, respectively. BIRM 270 did not inhibit 5-lipoxygenase activity in a cell-free assay. In addition, the compound did not interfere with the conversion of exogenous 5-lipoxygenase substrate (15S)-hydroperoxyeicosatetraenoic acid to (5S, 15S)-dihydroxyeicosatetraenoic acid in intact, ionophore-stimulated neutrophils. Under the same experimental conditions, BIRM 270 inhibited the production of 5-lipoxygenase products from endogenous substrate, suggesting that the compound affected arachidonate availability rather than metabolism. Consistent with this concept, the inhibition of leukotriene B4 biosynthesis by BIRM 270 was overcome by the addition of exogenous arachidonic acid to the leukocyte preparation. Direct measurement of free arachidonate by gas chromatography-mass spectrometry confirmed that BIRM 270 inhibited arachidonate release from ionophore-stimulated neutrophils. The compound did not affect arachidonate reacylation. The blockage of arachidonate release coincided with inhibition of leukotriene B4 biosynthesis in these cells. BIRM 270 also inhibited ionophore-stimulated platelet-activating factor biosynthesis by human neutrophils. Although these results suggest that BIRM 270 inhibited phospholipase A2-mediated deacylation of membrane phospholipids, the compound did not directly inhibit the high molecular weight, cytosolic phospholipase A2 derived from human neutrophils or U937 cells. Thus, suppression of arachidonate mobilization by BIRM 270 may be due to indirect inhibition of intracellular phospholipase A2 or to inhibition of another acylhydrolase activity.

  12. Protective effect of eicosapentaenoic acid on ouabain toxicity in neonatal rat cardiac myocytes

    Energy Technology Data Exchange (ETDEWEB)

    Hallaq, H.; Leaf, A. (Harvard Medical School, Boston, MA (USA)); Sellmayer, A. (Univ. Munchen, (Germany)); Smith, T.W. (Brigham and Women' s Hospital, Boston, MA (USA))

    1990-10-01

    Isolated neonatal cardiac myocytes have been utilized as a model for the study of cardiac arrhythmogenic factors. The myocytes respond to the toxic effects of a potent cardiac glycoside, ouabain at 0.1 mM, by an increase in their spontaneous beating rate and a reduction in amplitude of contractions resulting within minutes in a lethal state of contracture. Incubating the isolated myocytes for 3{endash}5 days in culture medium enriched with 5 {mu}M arachidonic acid had no effect on the development of lethal contracture after subsequent exposure to 0.1 mM ouabain. By contrast, incubating the myocytes for 3{endash}5 days with 5 {mu}M eicosapentaenoic acid completely prevented the toxic effects of ouabain at 0.1 mM. No differences in bumetanide-inhibitable {sup 86}Rb flux were observed between the three preparations. However, measurements with fura-2 of cytosolic free calcium levels indicated that control and arachidonic acid-enriched myocytes developed toxic cytosolic calcium concentrations of 845 {plus minus} 29 and 757 {plus minus} 64 nM, respectively, on exposure to 0.1 mM ouabain, whereas in eicosapentaenoic acid-enriched myocytes, physiologic calcium levels were preserved. Incubating the myocytes with eicosapentaenoic acid for 3{endash}5 days resulted in a small reduction of arachidonic acid and a small but significant increase of eicosapentaenoic acid in membrane phospolipids of the myocytes.

  13. Synergism interaction between arachidonic acid by 5-hydroxytryptamine in human platelet aggregation is mediated through multiple signalling pathways%多种信号途径介导花生四烯酸与5-羟色胺在促人类血小板凝集中的协同作用

    Institute of Scientific and Technical Information of China (English)

    Sheikh Arshad SAEED; Huma RASHEED; Anwar-ul-Hassan GILANI

    2003-01-01

    AIM: To examine the signalling mechanisms involved in the synergistic interaction of 5-hydroxytryptamine (5-HT)and arachidonic acid (AA) in human platelet aggregation. METHODS: Blood was obtained from healthy human subjects, mixed with 3.8 % sodium citrate (9:1), and centrifuged to prepare platelet rich plasma (PRP). Aggregation was monitored using a Dual-channel Lumi-aggregometer. The agonist-induced influx of Ca2+ was measured using Fura-2 AM. TXA2 formation was studied using radiochemical method. RESULTS: Subthreshold concentration of 5-HT (2 μmol/L) potentiated the effect of low dose of AA (0.2 mmol/L) in human platelets. This synergistic effect was blocked by 5-HT2 receptor antagonist (methysergide IC50=5.2 nmol/L; cyproheptadine IC50=0.6 nmol/L), and thromboxane A2 receptor antagonist (SQ 29 548; IC50=30 nmol/L), showing that the effect is receptor-mediated.To examine the down-stream signalling pathways, we found that such an interaction was inhibited by calcium channel blockers (diltiazem; IC50=3 μmol/L and verapamil; IC50=5 μmol/L), phospholipase C (PLC) inhibitor (U73122;IC50=4 μmol/L), cyclooxygenase inhibitor, (indomethacin; IC50=0.2 μmol/L) and mitogen-activated protein (MAP)kinase inhibitor (PD98059; IC50=3 μmol/L). The effect was also inhibited by a specific tyrosine light chain kinase (TLCK) inhibitor, herbimycin A with IC50 value of 5 μmol/L. Pretreatment of platelet with 5-HT and AA induced rise in intracellular calcium and this effect was blocked by verapamil. CONCLUSION: The synergism between 5-HT and AA in platelet aggregation involves activation of PLC/Ca2+, COX, and MAP kinase pathways.

  14. Comparison of humic acid rejection and flux decline during filtration with negatively charged and uncharged ultrafiltration membranes.

    Science.gov (United States)

    Shao, Jiahui; Hou, Juan; Song, Hongchen

    2011-01-01

    Increasingly stringent regulations for drinking water quality have stimulated the ultrafiltration (UF) to become one of the best alternatives replacing conventional drinking water treatment technologies. However, UF is not very effectively to remove humic acid due to the comparatively larger pore size compared to the size of humic acid. Fouling issue is another factor that restricts its widespread application. In this study, rejection of humic acid and flux decline were compared with essentially neutral, negatively charged version of a regenerated cellulose membrane, in which electrostatic interaction was explored for a better humic acid removal and less fouling. Solution environment, including ionic strength, pH and calcium ion concentration, affecting humic acid removal and flux decline on negatively charged and neutral membranes was also compared. Results indicated that the appropriate charge modification on the neutral UF membrane could be an effective way for better removal of NOM and reduction of the membrane fouling due to the electrostatic interactions with the combination effect of membrane pore size. Electrostatic interactions are significant important to achieve high humic acid removal and less fouling, and to improve the water quality and protect people's health. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. Cardiac lipoprotein lipase activity in the hypertrophied heart may be regulated by fatty acid flux.

    Science.gov (United States)

    Hauton, David; Caldwell, Germaine M

    2012-04-01

    Cardiac hypertrophy is characterised by an imbalance between lipid uptake and fatty acid β-oxidation leading to an accumulation of lipids, particularly triacylglycerol (TAG). It is unclear whether uptake mechanisms such as lipoprotein lipase (LPL) can be attenuated to diminish this uptake. Rats were cold acclimated to induce cardiac hypertrophy and increase cardiac LPL. Lipid uptake and metabolism were altered by feeding a 'Western-style' high fat diet (WSD) or feeding oxfenicine (2g/L) in the drinking water. Diastolic stiffness (increased volume change/unit pressure change) was induced in hypertrophied hearts for rats fed WSD (Pmuscle, estimated from stress-strain calculations was unchanged. Cold acclimation increased cardiac endothelial LPL (P<0.05) but this was diminished following oxfenicine. Following WSD LPL was further decreased below WSD-fed control hearts (P<0.05) with no further decrease by oxfenicine supplementation. A negative correlation was noted between plasma TAG and endothelial LPL (correlation coefficient=-0.654; P<0.001) but not cardiac TAG concentration. Transcript levels of angiopoietin-like protein-4 (ANGPTL4) were increased 6-fold by WSD (P<0.05) and increased 15-fold following WSD+oxfenicine (P<0.001). For CA-hearts fed WSD or WSD+oxfenicine ANGPTL4 mRNA levels were preserved at chow-fed levels. VLDLR protein levels were increased 10-fold (P<0.01) by CA. ANGPTL4 protein levels were increased 2-fold (P<0.05) by WSD, but restored following oxfenicine. For CA-hearts WSD increased ANGPTL4 protein levels 3-fold (P<0.01) with WSD+oxfenicine increasing ANGPTL4 protein 4-fold (P<0.01). These data suggest that endothelial LPL levels in the heart are altered to maintain FA flux and may exploit ANGPTL4. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Acid-base and ionic fluxes in rainbow trout (Oncorhynchus mykiss) during exposure to chloramine-T

    Energy Technology Data Exchange (ETDEWEB)

    Powell, M.D.; Perry, S.F. [Department of Biology, University of Ottawa, 30 Marie Curie Ottawa, Ontario, K1N 6N5 (Canada)

    1998-09-01

    The effects of chloramine-T and its degradation products, sodium hypochlorite (NaOCl) and para-toluenesulphonamide (pTSA), on whole body acid-base and branchial and renal ion (Na{sup +}and Cl{sup -}) fluxes were examined in rainbow trout (Oncorhynchus mykiss). Exposure to chloramine-T (3.5 h, 18 mg l{sup -1}) resulted in increases in plasma total CO{sub 2} but no coincident rise in P{sub a}CO{sub 2} or reduction in blood pH. Exposure of fish to 2, 9 or 18 mg l{sup -1} chloramine-T (3.5 h duration) resulted in a reduction in net acid uptake suggesting the development of a metabolic alkalosis. Exposure to the chloramine-T breakdown product pTSA (dissolved in DMSO) resulted in increased net acid uptake (decreased acid excretion) suggesting a metabolic acidosis. Whole body ion fluxes demonstrated increases in the losses of both Na{sup +}and Cl{sup -} with chloramine-T, NaOCl and pTSA. However, the effect of DMSO alone could not be isolated. Confirmatory studies using fish in which the urinary bladder (to allow collection of urine) and dorsal aorta (to allow injection of [{sup 14}C]polyethylene glycol 4000 ([{sup 14}C]PEG), an extracellular fluid marker) were catheterised, revealed that changes in whole body ion fluxes during chloramine-T exposure could not be explained by increased renal efflux through urine flow, glomerular filtration or renal clearance. Branchial effluxes of [{sup 14}C]PEG were not significantly affected by chloramine-T exposure suggesting that the changes in whole body ionic fluxes were caused by transcellular rather than paracellular processes. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  17. Influence of gas-particle partitioning on ammonia and nitric acid fluxes above a deciduous forest in the Midwestern USA

    Science.gov (United States)

    Hansen, K.; Sørensen, L. L.; Hornsby, K. E.; Boegh, E.; Pryor, S. C.

    2013-12-01

    Quantifying the atmosphere-biosphere exchange of reactive nitrogen gasses (including ammonia (NH3) and nitric acid (HNO3)) is crucial to assessing the impact of anthropogenic activities on natural and semi-natural ecosystems. However, measuring the deposition of reactive nitrogen is challenging due to bi-directionality of the flux, and the dynamics of the chemical gas/aerosol equilibrium of NH3 and HNO3 (or other atmospheric acids) with aerosol-phase ammonium (NH4+) and nitrate (NO3-). NH3 and HNO3 are both very reactive and typically exhibit higher deposition velocities than aerosol NH4+. Therefore, the phase partitioning between gas and aerosol phases can have a significant effect on local budgets and atmospheric transport distances (Nemitz et al., Atmos. Chem. Phys., 2004). In this study, fluxes of NH3, HNO3 and carbon dioxide (CO2) along with size-resolved N-aerosol concentrations are measured above the deciduous forest, Morgan Monroe State Forest (MMSF) in south-central Indiana (39°53'N, 86°25'W) during a field campaign. Two relaxed eddy accumulation (REA) systems are used to measure fluxes and concentrations of NH3 and HNO3 at 44 m. The NH3 REA system operates based on wet effluent diffusion denuders with detection by florescence and half-hourly flux measurements are calculated. HNO3 REA system is based on gas capture on sodium chloride (NaCl) coated denuders with subsequent analysis by ion-chromatography, and the resulting fluxes have a resolution of 3-4 hours. CO2 fluxes are measured by eddy covariance using a closed-path Licor LI-7500, while two MSP MOUDI-110 impactors are used to measure the 24-hourly average inorganic and 48 hourly averaged organic ion concentrations in 11 size bins, respectively, just above the canopy level (28 m). The results of this field campaign are used to quantify the fluxes of NH3, HNO3, CO2 to/from the forest during the transition towards senescence, and to investigate process-level controls (e.g. the role of phase

  18. Impact of suboxia on sinking particulate organic carbon: Enhanced carbon flux and preferential degradation of amino acids via denitrification

    Science.gov (United States)

    Van Mooy, Benjamin A. S.; Keil, Richard G.; Devol, Allan H.

    2002-02-01

    Fluxes of particulate organic carbon (POC) through the oxygen deficient waters in the eastern tropical North Pacific were found to be relatively less attenuated with depth than elsewhere in the eastern North Pacific. The attenuation coefficient (b) for the flux was found to be 0.40 versus the composite value of 0.86 determined by Martin et al. (1987). To examine this further, sinking POC was collected using sediment traps and allowed to degrade in oxic and suboxic experiments. Using a kinetic model, it was found that degradation proceeded at similar rates (roughly 0.8 day-1) under oxic and suboxic conditions, but a greater fraction of bulk POC was resistant to degradation in the suboxic experiments (61% vs. 23%). Amino acids accounted for 37% of POC collected at 75m, but following degradation the value dropped to 17% and 16% in the oxic and suboxic experiments respectively. POC collected from 500m was 10% amino acids. The non-AA component of POC collected at 75m was not degraded under suboxic conditions, while under oxic conditions it was. These results suggest that microbes degrading OC under suboxic conditions via denitrification preferentially utilize nitrogen-rich amino acids. This preferential degradation of amino acids suggests that 9% more nitrogen may be lost via water column denitrification than is accounted for when a more ;Redfieldian; stoichiometry for POC is assumed.

  19. Low Penetrance Alleles in Colorectal Cancer: the arachidonic acid pathway

    NARCIS (Netherlands)

    C.L.E. Siezen

    2006-01-01

    textabstractIn summary, we can conclude that we have successfully identified low penetrance alleles in the PPAR., PLA2G2A and ALOX15 genes, conferring differential colorectal adenoma risk, and two such alleles in the PTGS2 gene, one of which is also involved in colorectal cancer risk. These resul

  20. Association between polymorphisms of arachidonate 12-lipoxygenase (ALOX12 and schizophrenia in a Korean population

    Directory of Open Access Journals (Sweden)

    Park Jin

    2010-07-01

    Full Text Available Abstract Arachidonic acid (AA, an essential polyunsaturated fatty acid, is one of the major components of neural membranes, which show an altered phospholipid composition in schizophrenia. Arachidonate 12-lipoxygenase (ALOX12, an important enzyme, metabolizes AA to 12-HPETE, which affects catecholamine synthesis. However, research has yet to show the genetic association between ALOX12 and schizophrenia. Therefore, we investigated single nucleotide polymorphisms (SNP of the ALOX12 gene in schizophrenia, recruiting patients with schizophrenia (n = 289 and normal controls (n = 306 from a Korean population. We selected three SNPs (rs1126667, rs434473, and rs1042357 of the ALOX12 gene and genotyped them by direct sequencing. We reviewed the schizophrenic patients' medical records and assessed them clinically using the Brief Psychiatric Rating Scale (BPRS, the Scale for the Assessment of Negative Symptoms (SANS, and the Operational Criteria Checklist (OPCRIT. Then we statistically analyzed the genetic associations between the SNPs and schizophrenia, finding a genetic association between both rs1126667 and rs1042357 and schizophrenia, in the recessive model (p = 0.015 and 0.015, respectively. We also found an association between rs434473 and negative symptoms, defined through a factor analysis of the OPCRIT data (p = 0.040. Consequently, we suggest that SNPs of the ALOX12 gene might be associated with schizophrenia and negative symptoms in this Korean population. These weak positives require additional study.

  1. In vivo microdialysis studies on the effects of decortication and excitotoxic lesions on kainic acid-induced calcium fluxes, and endogenous amino acid release, in the rat striatum

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, S.P.; Lazarewicz, J.W.; Hamberger, A.

    1987-11-01

    The in vivo effects of kainate (1 mM) on fluxes of /sup 45/Ca2+, and endogenous amino acids, were examined in the rat striatum using the brain microdialysis technique. Kainate evoked a rapid decrease in dialysate /sup 45/Ca2+, and an increase in the concentration of amino acids in dialysates in Ca2+-free dialysates. Taurine was elevated six- to 10-fold, glutamate two- to threefold, and aspartate 1.5- to twofold. There was also a delayed increase in phosphoethanolamine, whereas nonneuroactive amino acids were increased only slightly. The kainic acid-evoked reduction in dialysate /sup 45/Ca2+ activity was attenuated in striata lesioned previously with kainate, suggesting the involvement of intrinsic striatal neurons in this response. The increase in taurine concentration induced by kainate was slightly smaller under these conditions. Decortication did not affect the kainate-evoked alterations in either dialysate /sup 45/Ca2+ or amino acids. These data suggest that kainate does not release acidic amino acids from their transmitter pools located in corticostriatal terminals.

  2. Computational estimation of tricarboxylic acid cycle fluxes using noisy NMR data from cardiac biopsies

    NARCIS (Netherlands)

    H. Hettling (Hannes); D.J. C. Alders (David); M.P. Heringa (Martijn); T.W. Binsl (Thomas); A.B.J. Groeneveld (Johan); J.H.G.M. van Beek (Johannes)

    2013-01-01

    textabstractBackground: The aerobic energy metabolism of cardiac muscle cells is of major importance for the contractile function of the heart. Because energy metabolism is very heterogeneously distributed in heart tissue, especially during coronary disease, a method to quantify metabolic fluxes in

  3. Effect of arachidonic acid supplementation and cyclooxygenase/lipoxygenase inhibition on the development of early bovine embryos Influência do ácido araquidónico e da inibição da ciclo-oxigenase ou lipo-oxigenase no desenvolvimento inicial de embriões bovinos

    Directory of Open Access Journals (Sweden)

    Rosa Maria Pereira

    2006-04-01

    Full Text Available The effect of arachidonic acid (AA cascade on bovine embryo development in a granulosa cell co-culture system was studied. Arachidonic acid (100 µM was supplemented from 1-cell to 8-16 cell block stage (first three days of co-culture and from 1-cell to hatching. Specific cyclooxygenase (indomethacin, 28 µM and lipoxygenase (nordihydroguaiaretic acid - NDGA, 28 µM inhibitors were used from 1-cell to 8-16 cell block stage with AA. Embryo development was assessed by cleavage, day 7-day 8 and hatched embryo rates and by measuring growth rates through development stages found in days 7-10 of culture (day 0 = insemination day. Embryo quality was scored at day 8. A 6.5-10.4% increase on cleavage rate after AA supplementation was found. This AA supplementation from 1-cell to hatching delayed embryo growth rate beyond day 7 and a reduction on hatching rate was detected. When AA supplementation was restricted to the first three days of co-culture those negative effects were overcome. Also, indomethacin and NDGA prevented the positive effect of AA and induced a significant reduction on cleavage, respectively. NDGA further decreased day 7 embryo rate and quality. Results suggest that AA has a two-phase action on bovine embryos, promoting early development and impairing embryo growth from day 7 onwards and hatching rates. Both cyclooxygenase and lipoxygenase were found to be important pathways to promote cleavage.Estudou-se a influência da cascata do ácido araquidónico (AA no desenvolvimento de embriões bovinos produzidos in vitro em co-cultura com células da granulosa. Os embriões foram suplementados com AA (100 µM desde o estádio de 1 célula até 8-16 células (primeiros três dias de co-cultura ou até a eclosão. Introduziram-se inibidores específicos da ciclo-oxigenase (indometacina, 28 µM e da lipo-oxigenase (ácido nordihidroguaiarético - NDGA, 28 µM, juntamente com o ácido araquidónico, desde o estádio de 1 célula até 8-16 c

  4. Lipotoxic Palmitate Impairs the Rate of β-Oxidation and Citric Acid Cycle Flux in Rat Neonatal Cardiomyocytes.

    Science.gov (United States)

    Haffar, Taha; Akoumi, Ali; Bousette, Nicolas

    2016-01-01

    Diabetic hearts exhibit intracellular lipid accumulation. This suggests that the degree of fatty acid oxidation (FAO) in these hearts is insufficient to handle the elevated lipid uptake. We previously showed that palmitate impaired the rate of FAO in primary rat neonatal cardiomyocytes. Here we were interested in characterizing the site of FAO impairment induced by palmitate since it may shed light on the metabolic dysfunction that leads to lipid accumulation in diabetic hearts. We measured fatty acid oxidation, acetyl-CoA oxidation, and carnitine palmitoyl transferase (Cpt1b) activity. We measured both forward and reverse aconitase activity, as well as NAD+ dependent isocitrate dehydrogenase activity. We also measured reactive oxygen species using the 2', 7'-Dichlorofluorescin Diacetate (DCFDA) assay. Finally we used thin layer chromatography to assess diacylglycerol (DAG) levels. We found that palmitate significantly impaired mitochondrial β-oxidation as well as citric acid cycle flux, but not Cpt1b activity. Palmitate negatively affected net aconitase activity and isocitrate dehydrogenase activity. The impaired enzyme activities were not due to oxidative stress but may be due to DAG mediated PKC activation. This work demonstrates that palmitate, a highly abundant fatty acid in human diets, causes impaired β-oxidation and citric acid cycle flux in primary neonatal cardiomyocytes. This metabolic defect occurs prior to cell death suggesting that it is a cause, rather than a consequence of palmitate mediated lipotoxicity. This impaired mitochondrial metabolism can have important implications for metabolic diseases such as diabetes and obesity. © 2016 The Author(s) Published by S. Karger AG, Basel.

  5. Lipotoxic Palmitate Impairs the Rate of β-Oxidation and Citric Acid Cycle Flux in Rat Neonatal Cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Taha Haffar

    2016-12-01

    Full Text Available Background/Aims: Diabetic hearts exhibit intracellular lipid accumulation. This suggests that the degree of fatty acid oxidation (FAO in these hearts is insufficient to handle the elevated lipid uptake. We previously showed that palmitate impaired the rate of FAO in primary rat neonatal cardiomyocytes. Here we were interested in characterizing the site of FAO impairment induced by palmitate since it may shed light on the metabolic dysfunction that leads to lipid accumulation in diabetic hearts. Methods: We measured fatty acid oxidation, acetyl-CoA oxidation, and carnitine palmitoyl transferase (Cpt1b activity. We measured both forward and reverse aconitase activity, as well as NAD+ dependent isocitrate dehydrogenase activity. We also measured reactive oxygen species using the 2', 7'-Dichlorofluorescin Diacetate (DCFDA assay. Finally we used thin layer chromatography to assess diacylglycerol (DAG levels. Results: We found that palmitate significantly impaired mitochondrial β-oxidation as well as citric acid cycle flux, but not Cpt1b activity. Palmitate negatively affected net aconitase activity and isocitrate dehydrogenase activity. The impaired enzyme activities were not due to oxidative stress but may be due to DAG mediated PKC activation. Conclusion: This work demonstrates that palmitate, a highly abundant fatty acid in human diets, causes impaired β-oxidation and citric acid cycle flux in primary neonatal cardiomyocytes. This metabolic defect occurs prior to cell death suggesting that it is a cause, rather than a consequence of palmitate mediated lipotoxicity. This impaired mitochondrial metabolism can have important implications for metabolic diseases such as diabetes and obesity.

  6. Influence of gas-particle partitioning on ammonia and nitric acid fluxes above a deciduous forest in the Midwestern USA

    DEFF Research Database (Denmark)

    Hansen, Kristina; Sørensen, Lise Lotte; Hornsby, Karen E.

    Quantifying the atmosphere-biosphere exchange of reactive nitrogen gasses (including ammonia (NH3) and nitric acid (HNO3)) is crucial to assessing the impact of anthropogenic activities on natural and semi-natural ecosystems. However, measuring the deposition of reactive nitrogen is challenging due...... are measured above the deciduous forest, Morgan Monroe State Forest (MMSF) in south-central Indiana (39°53’N, 86°25’W) during a field campaign. Two relaxed eddy accumulation (REA) systems are used to measure fluxes and concentrations of NH3 and HNO3 at 44 m. The NH3 REA system operates based on wet effluent...

  7. Comparison of increased arachidonic acid content in Myrmecia incisa cultured during the course of nitrogen or phosphorus starvation%氮饥饿与磷饥饿促使缺刻缘绿藻花生四烯酸含量增加的比较

    Institute of Scientific and Technical Information of China (English)

    童牧; 于水燕; 欧阳珑玲; 周志刚

    2011-01-01

    The growth rate and biomass,contents of arachidonic acid(AA) and other fatty acids in Myrmecia incisa Reisigl H4301, a freshwater green microalga rich in AA, were comparatively studied while cultured between nitrogen and phosphorus starvation under different light intensities. It was found that either nitrogen or phosphorus starvation could cause a reduced growth rate of this microalga as well as a resultant biomass.If grown under a lower light intensity [ 60 μmol photons/( m2 · s) ], the lowest average growth rate [ 0.025 g/( d · L) ] of this microalga resulted from phosphorus starvation, which was nearly half of the growth rate while grown in a complete BG-11 medium. Both of nitrogen and phosphorus starvation could increase the contents of total fatty acids and AA,however, when this alga was exposed to low light intensity the positive effect of phosphorus starvation was limited. High light intensity [ 200 μmol photons/( m2 · s ) ] was not beneficial to the synthesis and accumulation of AA no matter how this microalga was cultured in the complete or nitrogen-free or phosphorus-free media. The AA content gradually increased accompanying with a decrease of linoleic acid content during the starvation. However, the oleic acid percentage also gradually increased which limited more significantly the accumulation of AA in this microalga grown under phosphorus starvation than nitrogen one. Based on the composition changes of every species of fatty acids, the main synthesis metabolic pathway of AA suggested that it proceeded from linoleic acid to γ-linolenic acid and then to 20:3ω6 under nitrogen or phosphate starvation,and that the Δ6 desaturase was a rate-limiting enzyme. The step in which ω3 desaturase played was down regulated by nitrogen or phosphorus starvation, thus ensuring the synthesis and accumulation of AA positively. Nitrogen starvation blocked the protein synthesis, and phosphorus starvation caused the disorders of nucleic acid, carbohydrate and

  8. ρ0 Cells Feature De-Ubiquitination of SLC Transporters and Increased Levels and Fluxes of Amino Acids

    Directory of Open Access Journals (Sweden)

    André Bordinassi Medina

    2017-04-01

    Full Text Available Solute carrier (SLC transporters are a diverse group of membrane transporter proteins that regulate the cellular flux and distribution of endogenous and xenobiotic compounds. Post-translational modifications (PTMs, such as ubiquitination, have recently emerged as one of the major regulatory mechanisms in protein function and localization. Previously, we showed that SLC amino acid transporters were on average 6-fold de-ubiquitinated and increased amino acid levels were detected in ρ0 cells (lacking mitochondrial DNA, mtDNA compared to parental cells. Here, we elucidated the altered functionality of SLC transporters and their dynamic ubiquitination status by measuring the uptake of several isotopically labeled amino acids in both human osteosarcoma 143B.TK- and ρ0 cells. Our pulse chase analysis indicated that de-ubiquitinated amino acid transporters in ρ0 cells were accompanied by an increased transport rate, which leads to higher levels of amino acids in the cell. Finding SLC transport enhancers is an aim of the pharmaceutical industry in order to compensate for loss of function mutations in these genes. Thus, the ubiquitination status of SLC transporters could be an indicator for their functionality, but evidence for a direct connection between de-ubiquitination and transporter activity has to be further elucidated.

  9. River inputs and organic matter fluxes in the northern Bay of Bengal: Fatty acids

    Digital Repository Service at National Institute of Oceanography (India)

    Reemtsma, T.; Ittekkot, V.; Bartsch, M.; Nair, R.R.

    of particulate material on its way from the shal- low (809 m) to the deep trap ( 1750 m) follow some well known trends (Table 2 ). Saturated fatty acids, namely the long-chain homo- logues, become relatively enriched, since sta- bility of fatty acids rises...

  10. Maximising metal ions flux across a microdialysis membrane by incorporating poly-L-aspartic acid, poly-L-histidine, 8-hydroxyquinoline and ethylenediaminetetraacetic acid in the perfusion liquid

    Energy Technology Data Exchange (ETDEWEB)

    Mogopodi, Dikabo [University of Botswana, Department of Chemistry, Private Bag UB 00704, Gaborone (Botswana); Torto, Nelson [University of Botswana, Department of Chemistry, Private Bag UB 00704, Gaborone (Botswana)]. E-mail: torton@mopipi.ub.bw

    2005-04-08

    This paper presents a study of quiescent microdialysis sampling of Cr{sup 3+}, Cu{sup 2+}, Ni{sup 2+} and Pb{sup 2+} involving the incorporation of poly-L-aspartic acid, poly-L-histidine, 8-hydroxyquinoline (8-HQ) and ethylenediaminetetraacetic acid (EDTA), in the perfusion liquid as an approach to maximise metal analyte flux across the microdialysis membrane. These chelating agents were individually optimised with respect to microdialysis recovery and subsequently combined in the perfusion liquid. A combination of 20% (w/v) poly-L-histidine, 0.032% (w/v) poly-L-aspartic acid and 1 mM 8-HQ achieved microdialysis recovery up to 90%. Since 1 mM EDTA achieved recoveries greater than 80% for all metals understudy, EDTA was not combined with any of the chelating agents. Under the optimal conditions of maximum metal ion flux across the microdialysis membrane, metal ions from natural and wastewater were sampled and analysed with an electrothermal atomic absorption spectrometer equipped with a Zeeman background corrector. Results showed higher concentrations of detected metal ions after microdialysis sampling compared to direct detection without sample clean-up. Incorporation of chelating agents in the microdialysis perfusion liquid enhanced metal ions recovery in real samples and achieved enrichment factors of up to 42. The study demonstrated that combining chelating agents is a good approach towards maximising metal flux across the dialysis membrane. Given that recoveries between 80 and 90% were achieved under quiescent microdialysis sampling conditions, these findings are an important development for in vivo diagnostic sampling of metal ions.

  11. Arachidonate metabolism increases as rat alveolar type II cells differentiate in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Lipchik, R.J.; Chauncey, J.B.; Paine, R.; Simon, R.H.; Peters-Golden, M. (Univ. of Michigan, Ann Arbor (USA))

    1990-08-01

    Rat type II alveolar epithelial cells are known to undergo morphological and functional changes when maintained in culture for several days. Having previously demonstrated that these cells can deacylate free arachidonic acid (AA) and metabolize it to products of the cyclooxygenase pathway, the present study was undertaken to determine whether in vitro differentiation was accompanied by alterations in the availability and metabolism of AA. We assessed the constitutive and ionophore A23187-induced deacylation and metabolism of endogenous AA, as well as the metabolism of exogenously supplied AA, in primary cultures of rat type II cells at days 2, 4, and 7 after isolation. Levels of free endogenous AA were increased at day 4, whereas eicosanoid synthesis, predominantly prostaglandin E2 and prostacyclin, increased markedly only at day 7. A similar time course of augmentation of prostanoid release was seen in response to exogenous AA. Type II cells cultured on fibronectin, intended to hasten cell flattening and spreading, demonstrated accelerated increases in available free AA in response to A23187; cells cultured on basement membrane derived from Engelbreth-Holm-Swarm mouse sarcoma, known to maintain the type II phenotype, exhibited diminished levels of available free AA. From these findings, we conclude that alterations in arachidonate metabolism are linked to alterations in cellular phenotype. The potentiation of eicosanoid synthesis accompanying in vitro differentiation suggests a possible role for the alveolar epithelium in the modulation of inflammation and fibrosis in the distal lung.

  12. Stage-Specific Fatty Acid Fluxes Play a Regulatory Role in Glycerolipid Metabolism during Seed Development in Jatropha curcas L.

    Science.gov (United States)

    Chaitanya, Bharatula Sri Krishna; Kumar, Sumit; Kaki, Shiva Shanker; Balakrishna, Marrapu; Karuna, Mallampalli Sri Lakshmi; Prasad, Rachapudi Badari Narayana; Sastry, Pidaparty Seshadri; Reddy, Attipalli Ramachandra

    2015-12-23

    The present study describes the changes in lipid profile as well as fatty acid fluxes during seed development in Jatropha curcas L. Endosperm from 34, 37, and 40 days after anthesis (DAA), incubated with [(14)C]acetate, showed significant synthesis of phosphatidylcholine (PC) at seed maturation. The fatty acid methyl ester profile showed PC from 34 DAA was rich in palmitic acid (16:0), whereas PC from 37 and 40 DAA was rich in oleic acid (18:1n-9). Molecular species analysis of diacylglycerol (DAG) indicated DAG (16:0/18:2n-6) was in abundance at 34 DAA, whereas DAG (18:1n-9/18:2n-6) was significantly high at 40 DAA. Triacylglycerol (TAG) analysis revealed TAG (16:0/18:2n-6/16:0) was abundant at 34 DAA, whereas TAG (18:1n-9/18:2n-6/18:1n-9) formed the majority at 40 DAA. Expression of two types of diacylglycerol acyltransferases varied with seed maturation. These data demonstrate stage-specific distinct pools of PC and DAG synthesis during storage TAG accumulation in Jatropha seed.

  13. Regulation of adipose branched chain amino acid catabolism enzyme expression and cross-adipose amino acid flux in human obesity

    Science.gov (United States)

    Elevated blood branched chain amino acids (BCAA) are often associated with insulin resistance and type 2 diabetes. One possibility is that under these conditions there is a reduced cellular utilization and/or lower complete oxidation of BCAAs. White adipose tissue (WAT) has become appreciated as a...

  14. Investigating the stomatal, cuticular and soil ammonia fluxes over a growing tritical crop under high acidic loads

    Directory of Open Access Journals (Sweden)

    B. Loubet

    2011-10-01

    Full Text Available Ammonia concentration and fluxes were measured above a growing triticale field for two months during May and June 2010 at the NitroEurope crop site in Grignon (Fr-Gri near Paris, France. The measurement campaign started 15 days following a 40 kg N ha−1 application of an ammonium nitrate solution. A new mini-WEDD (Wet Effluent Denuder flow injection analyser with three channels (ROSAA, RObust and Sensitive Ammonia Analyser was used to measure NH3 fluxes using the aerodynamic gradient method. The measured ammonia concentrations varied from 0.01 to 39 μg NH3 m−3 and were largely influenced by advection from the nearby farm. The ammonia fluxes ranged from −560 to 220 ng NH3 m−2 s−1 and averaged −29 ng NH3 m−2 s−1. During some periods the large deposition fluxes could only be explained by a very small surface resistance, which may be due to the high concentrations in certain acid gases (HNO3 and SO2 observed in this suburban area. Ammonia emissions were also measured occasionally. The canopy compensation point Cc was around 1.5 μg NH3 m−3 on average. The canopy emission potential Γc (Cc normalised for the temperature response of the Henry equilibrium decreased over the course of the measurement campaign from Γc = 2200 to Γc = 450, the latter value being close to the median stomatal emission potential (Γs for managed ecosystems reported in the literature. The temporal dynamics of the measured NH3 flux compared well with the Surfatm- NH3 model using fitted parameters. The subjectivity of the model fitting is discussed based on a sensitivity analysis.

  15. Investigating the stomatal, cuticular and soil ammonia fluxes over a growing tritical crop under high acidic loads

    Directory of Open Access Journals (Sweden)

    B. Loubet

    2012-04-01

    Full Text Available Ammonia concentration and fluxes were measured above a growing triticale field for two months during May and June 2010 at the NitroEurope crop site in Grignon (Fr-Gri near Paris, France. The measurement campaign started 15 days following a 40 kg N ha−1 application of an ammonium nitrate solution. A new mini-wedd (Wet Effluent Denuder flow injection analyser with three channels (ROSAA, RObust and Sensitive Ammonia Analyser was used to measure NH3 fluxes using the aerodynamic gradient method. The measured ammonia concentrations varied from 0.01 to 39 μg NH3 m−3 and were largely influenced by advection from the nearby farm. The ammonia fluxes ranged from –560 to 220 ng NH3 m−2 s−1 and averaged –29 ng NH3 m−2 s−1. During some periods the large deposition fluxes could only be explained by a very small surface resistance, which may be partly due to the high concentrations of certain acid gases (HNO3 and SO2 observed in this suburban area. Ammonia emissions were also observed. The canopy compensation point Cc was around 1.5 μg NH3 m−3 on average. The canopy emission potential Γc (Cc normalised for the temperature response of the Henry equilibrium decreased over the course of the measurement campaign from Γc = 2200 to Γc = 450, the latter value being close to the median stomatal emission potential (Γs and lower than the median ground emission potential (Γg for managed ecosystems reported in the literature. The temporal dynamics of the measured NH3 flux compared well with the Surfatm-NH3 model using fitted parameters. The subjectivity of the model fitting is discussed based on a sensitivity analysis.

  16. Metal and acidity fluxes controlled by precipitation/dissolution cycles of sulfate salts in an anthropogenic mine aquifer

    Science.gov (United States)

    Cánovas, C. R.; Macías, F.; Pérez-López, R.

    2016-05-01

    Underground mine drainages are extremely difficult to study due to the lack of information about the flow path and source proximity in relation to the outflow adit. Geochemical processes controlling metals and acidity fluxes in a complex anthropogenic mine aquifer in SW Spain during the dry and rainy season were investigated by geochemical and statistical tools. High concentrations of acidity, sulfate, metals and metalloids (e.g. Fe, Cu, Zn, As, Cd, Ni, Co) were observed due to intense sulfide oxidation processes. The high residence time inside the anthropogenic aquifer, around 40 days, caused the release of significant quantities of metals linked to host rocks (e.g. Al, Ca, Ge, Li, Mg, REE). The most outstanding characteristic of the acid mine drainage (AMD) outflows is the existence of higher Fe/SO4 molar ratios than those theoretical of pyrite (0.50) during most of the monitored period, due to a fire which occurred in 1949 and remained active for decades. Permanent and temporal retention mechanisms of acidity and metals were observed in the galleries. Once released from sulfide oxidation, Pb and As are sorbed on Fe oxyhydroxysulfate or precipitated as low solubility minerals (i.e. anglesite) inside the galleries. The precipitation of evaporitic sulfate salts during the dry season and the subsequent re-dissolution after rainfall control the fluxes of acidity and main metals (i.e. Fe, Mg, Al) from this anthropogenic aquifer. Some elements, such as Cd, Cu, Ni, REE and Zn, are retained in highly soluble sulfate salts while other elements, such as Ge, Pb and Sc, have a lower response to washout processes due to its incorporation in less soluble sulfate salts. In this way, metal concentration during the washout processes would be controlled by the proportion and solubility of each type of evaporitic sulfate salt stored during the dry season. The recovery of metals of economic interest contained in the AMD could help to self-finance the remediation of these waters in

  17. Fluxes of amino acids and hexosamines to the deep Arabian sea

    Digital Repository Service at National Institute of Oceanography (India)

    Haake, B.; Ittekkot, V.; Ramaswamy, V.; Nair, R.R.; Honjo, S.

    Results of organic carbon, total nitrogen, amino acid and hexosamine of samples collected during time-series sediment trap in investigations in the Arabian Sea are presented. Samples were taken over a period of 1 1/2 years at two depths at each...

  18. Synthesis and regulation of chlorogenic acid in potato: Rerouting phenylpropanoid flux in HQT silenced lines

    Science.gov (United States)

    Chlorogenic acid (CGA) is the major phenolic sink in potato tubers and can constitute over 90% of total phenylpropanoids. The regulation of CGA biosynthesis in potato and the role of the CGA biosynthetic gene hydroxycinnamoyl-CoA:quinate hydroxycinnamoyl transferase (HQT) was characterized. A sucros...

  19. Legionella pneumophila couples fatty acid flux to microbial differentiation and virulence.

    Science.gov (United States)

    Edwards, Rachel L; Dalebroux, Zachary D; Swanson, Michele S

    2009-03-01

    During its life cycle, Legionella pneumophila alternates between at least two phenotypes: a resilient, infectious form equipped for transmission and a replicative cell type that grows in amoebae and macrophages. Considering its versatility, we postulated that multiple cues regulate L. pneumophila differentiation. Beginning with a Biolog Phenotype MicroArray screen, we demonstrate that excess short-chain fatty acids (SCFAs) trigger replicative cells to cease growth and activate their panel of transmissive traits. To co-ordinate their response to SCFAs, L. pneumophila utilizes the LetA/LetS two-component system, but not phosphotransacetylase or acetyl kinase, two enzymes that generate high-energy phosphate intermediates. Instead, the stringent response enzyme SpoT appears to monitor fatty acid biosynthesis to govern transmission trait expression, as an altered distribution of acylated acyl carrier proteins correlated with the SpoT-dependent differentiation of cells treated with either excess SCFAs or the fatty acid biosynthesis inhibitors cerulenin and 5-(tetradecyloxy)-2-furoic acid. We postulate that, by exploiting the stringent response pathway to couple cellular differentiation to its metabolic state, L. pneumophila swiftly acclimates to stresses encountered in its host or the environment, thereby enhancing its overall fitness.

  20. The key to acetate: metabolic fluxes of acetic acid bacteria under cocoa pulp fermentation-simulating conditions.

    Science.gov (United States)

    Adler, Philipp; Frey, Lasse Jannis; Berger, Antje; Bolten, Christoph Josef; Hansen, Carl Erik; Wittmann, Christoph

    2014-08-01

    Acetic acid bacteria (AAB) play an important role during cocoa fermentation, as their main product, acetate, is a major driver for the development of the desired cocoa flavors. Here, we investigated the specialized metabolism of these bacteria under cocoa pulp fermentation-simulating conditions. A carefully designed combination of parallel 13C isotope labeling experiments allowed the elucidation of intracellular fluxes in the complex environment of cocoa pulp, when lactate and ethanol were included as primary substrates among undefined ingredients. We demonstrate that AAB exhibit a functionally separated metabolism during coconsumption of two-carbon and three-carbon substrates. Acetate is almost exclusively derived from ethanol, while lactate serves for the formation of acetoin and biomass building blocks. Although this is suboptimal for cellular energetics, this allows maximized growth and conversion rates. The functional separation results from a lack of phosphoenolpyruvate carboxykinase and malic enzymes, typically present in bacteria to interconnect metabolism. In fact, gluconeogenesis is driven by pyruvate phosphate dikinase. Consequently, a balanced ratio of lactate and ethanol is important for the optimum performance of AAB. As lactate and ethanol are individually supplied by lactic acid bacteria and yeasts during the initial phase of cocoa fermentation, respectively, this underlines the importance of a well-balanced microbial consortium for a successful fermentation process. Indeed, AAB performed the best and produced the largest amounts of acetate in mixed culture experiments when lactic acid bacteria and yeasts were both present.

  1. Platelet adhesion, contact phase coagulation activation, and C5a generation of polyethylene glycol acid-grafted high flux cellulosic membrane with varieties of grafting amounts.

    Science.gov (United States)

    Fushimi, F; Nakayama, M; Nishimura, K; Hiyoshi, T

    1998-10-01

    Grafting of polyethylene glycol chains onto cellulosic membrane can be expected to reduce the interaction between blood (plasma protein and cells) and the membrane surface. Alkylether carboxylic acid (PEG acid) grafted high flux cellulosic membranes for hemodialysis, in which the polyethylene glycol chain bears an alkyl group at one side and a carboxyl group at the other side, have been developed and evaluated. PEG acid-grafted high flux cellulosic membranes with various grafting amounts have been compared with respect to platelet adhesion, the contact phase of blood coagulation, and complement activation in vitro. A new method of quantitating platelet adhesion on hollow-fiber membrane surfaces has been developed, which is based on the determination of lactate dehydrogenase (LDH) activity after lysis of the adhered platelets. PEG acid-grafted high flux cellulosic membranes showed reduced platelet adhesion and complement activation effects in grafting amounts of 200 ppm or higher without detecting adverse effects up to grafting amounts of 850 ppm. The platelet adhesion of a PEG acid-grafted cellulosic membrane depends on both the flux and grafting amounts of the membrane. It is concluded that the grafting of PEG acid onto a cellulosic membrane improves its biocompatibility as evaluated in terms of platelet adhesion, complement activation, and thrombogenicity.

  2. Downward flux of particulate fatty acids in the Central Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Reemtsma, T.; Haake, B.; Ittekkot, V.; Nair, R.R.; Brockmann, U.H.

    species often overlap, however, and also are dependent on environmental factors such as nutrient supply, temperature, pressure and light intensity (Lee et al., 1971; Smith and Morris, 1980; Morris, 1984; de Long and Yayanos, 1986). Hence, the use....2 m of toluene to the dried extracts 2 ml of double-distilled water were added and the mixture was extracted three times with n-hexane. Fatty acid methyl esters (FAME) were separated from long-chain alcohols and hydrocarbons by thin- layer...

  3. Omega-3 Fatty Acids and Inflammatory Processes

    Directory of Open Access Journals (Sweden)

    Philip C. Calder

    2010-03-01

    Full Text Available Long chain fatty acids influence inflammation through a variety of mechanisms; many of these are mediated by, or at least associated with, changes in fatty acid composition of cell membranes. Changes in these compositions can modify membrane fluidity, cell signaling leading to altered gene expression, and the pattern of lipid mediator production. Cell involved in the inflammatory response are typically rich in the n-6 fatty acid arachidonic acid, but the contents of arachidonic acid and of the n-3 fatty acids eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA can be altered through oral administration of EPA and DHA. Eicosanoids produced from arachidonic acid have roles in inflammation. EPA also gives rise to eicosanoids and these often have differing properties from those of arachidonic acid-derived eicosanoids. EPA and DHA give rise to newly discovered resolvins which are anti-inflammatory and inflammation resolving. Increased membrane content of EPA and DHA (and decreased arachidonic acid content results in a changed pattern of production of eicosanoids and resolvins. Changing the fatty acid composition of cells involved in the inflammatory response also affects production of peptide mediators of inflammation (adhesion molecules, cytokines etc.. Thus, the fatty acid composition of cells involved in the inflammatory response influences their function; the contents of arachidonic acid, EPA and DHA appear to be especially important. The anti-inflammatory effects of marine n-3 PUFAs suggest that they may be useful as therapeutic agents in disorders with an inflammatory component.

  4. [EFfect of quinazolone-alkyl-carboxylic acid derivatives on the transmembrane Ca2+ ion flux mediated by AMPA receptors].

    Science.gov (United States)

    Szárics, Eva; LaszTóczi, Bálint; Nyikos, Lajos; Barabás, Péter; Kovács, Ilona; Skuban, Nina; Nagy, Péter I; Kökösi, József; Takácsné, Novák Krisztina; Kardos, Julianna

    2002-01-01

    The excitatory neurotransmitter, Glu, plays a crucial role in many sensory and motor functions as well as in brain development, learning and memory and it is also involved in the pathogenesis of a number of neurological disorders, including epilepsy, Alzheimer's and Parkinson's diseases. Therefore, the study of Glu receptors (GluRs) is of therapeutical importance. We showed here by fluorescence monitoring of transmembrane Ca2+ ion fluxes in response to (S)-alpha-amino-3-hidroxi-5-metil-4-izoxazol propionic acid ((S)-AMPA) on the time scale of 0.00004-10 s that Ca2+ ion influx proceeds through faster and slower desensitizing receptors. Pharmacological isolation of the slower and faster desensitizing AMPA receptor was possible by fluorescence monitoring of Ca2+ ion translocation in response to (S)-AMPA in the presence and absence of various 2-methyl-4-oxo-3H-quinazoline-3-alkyl-carboxilic acid derivatives (Qxs): the acetic acid Q1 inhibits the slower desensitizing receptor response specifically, while the acetyl-piperidine Q5 is a more potent inhibitor of the faster desensitizing receptor response. In addition, spontaneous interictal activity, as induced by high [K+] conditions in hippocampal slices, was reduced significantly by Q5, suggesting a possible anticonvulsant property of Q5. Substitutions of Qxs into the GluR2 S1S2 binding core were consistent with their effect by causing variable degree of S1S2 bridging interaction as one of the main determinants of AMPA receptor agonist activity. The exploitation of differences between similar receptors will be important in the development and use of drugs with high pharmacological specificity.

  5. Metabolically Engineered Fungal Cells With Increased Content Of Polyunsaturated Fatty Acids

    DEFF Research Database (Denmark)

    2008-01-01

    This invention relates to the production of fatty acids and particularly to the production of the polyunsaturated fatty acids (PUFAs) arachidonic acid (ARA) and eicosapentaenoic acid (EPA) in genetically engineered fungal cells, in particular, to metabolically engineered Saccharomyces cerevisiae...

  6. The effect of lipid and aqueous solubilities on flux of nicotinic acid esters from water through silicone membrane.

    Science.gov (United States)

    Synovec, Jennifer; Wasdo, Scott C; Sloan, Kenneth B

    2013-09-01

    The maximum fluxes (J(M)) of nicotinic acid esters (NAE) across silicone membranes from water (J(MPAQ)) have been measured to determine how well they correlate with J(M) of NAE across human skin from water in vitro (J(MHAQ)) and in vivo (J(MHAQ1)) and with J(M) of NAE across hairless mouse skin from water (J(MMAQ)). The NAE were all commercially available. Solubilities in water (S(AQ)), isopropyl myristate (S(IPM)) and octanol (S(OCT)) were obtained from literature sources. J(MPAQ) were measured at saturation for all the esters except the methyl ester. In that case, flux was measured at a concentration (C) less than saturation (J(PAQ)) and converted to J(MPAQ) = (J(PAQ))(S(AQ)/C(AQ)). J(MPAQ) values predicted from the previously reported coefficients to the parameters in the Roberts-Sloan (RS) equation (PRE J(MPAQ)) were substantially lower than the experimental J(MPAQ) values (EXP J(MPAQ)) values obtained here. The EXP J(MPAQ) were incorporated into the previous J(MPAQ) database and new coefficients were obtained: x = -1.837; y = 0.742; z = 0.00435; r² = 0.86. Correlation of J(MPAQ) values with J(MHAQ), J(MHAQ1), and J(MMAQ) values show the same trend as the J(MPAQ) values. The inclusion of the NAE n = 6 data into the previous n = 32 database for the permeation of the prodrugs through a silicone membrane from water (J(MPAQ)) greatly improved the fit of the n = 38 database to the RS equation: r² = 0.86 vs r² = 0.77. The correlation between log J(MHAQ) and log J(MPAQ) gave r² = 0.98. This suggests that J(MPAQ) values are good predictors of J(MHAQ) values.

  7. Effect of dietary neutral detergent fiber on ileal digestibility and portal flux of nitrogen and amino acids and on the nitrogen utilization in growing pigs

    NARCIS (Netherlands)

    Lenis, N.P.; Bikker, P.; Meulen, van der J.; Diepen, van J.Th.M.; Bakker, J.G.M.; Jongbloed, A.W.

    1996-01-01

    Two experiments were conducted to determine the effects of dietary NDF on apparent ileal and fecal digestibility and portal flux of nitrogen (N) and amino acids, and on N retention in growing pigs. In four equal portions (at 0600, 1200, 1800, and 2400) barrows on Treatment B received a basal diet, b

  8. 13C Metabolic Flux Analysis for Systematic Metabolic Engineering of S. cerevisiae for Overproduction of Fatty Acids

    DEFF Research Database (Denmark)

    Ghosh, Amit; Ando, David; Gin, Jennifer

    2016-01-01

    Efficient redirection of microbial metabolism into the abundant production of desired bioproducts remains non-trivial. Here, we used flux-based modeling approaches to improve yields of fatty acids in Saccharomyces cerevisiae. We combined 13C labeling data with comprehensive genome-scale models to...

  9. A simple mathematical model and practical approach for evaluating citric acid cycle fluxes in perfused rat hearts by 13C-NMR and 1H-NMR spectroscopy.

    Science.gov (United States)

    Tran-Dinh, S; Hoerter, J A; Mateo, P; Bouet, F; Herve, M

    1997-04-15

    We propose a simple mathematical model and a practical approach for evaluating the flux constant and the absolute value of flux in the citric acid cycle in perfused organs by 13C-NMR and 1H-NMR spectroscopy. We demonstrate that 13C-NMR glutamate spectra are independent of the relative sizes of the mitochondrial and cytosolic compartments and the exchange rates of glutamates, unless there is a difference in 13C chemical shifts of glutamate carbons between the two compartments. Wistar rat hearts (five beating and four KCl-arrested hearts) were aerobically perfused with 100% enriched [2-(13)C]acetate and the kinetics of glutamate carbon labeling from perchloric acid extracts were studied at various perfusion times. Under our experimental conditions, the citric acid cycle flux constant, which represents the fraction of glutamate in exchange with the citric acid cycle per unit time, is about 0.350 +/- 0.003 min(-1) for beating hearts and 0.0741 +/- 0.004 min(-1) for KCl-arrested hearts. The absolute values of the citric acid flux for beating hearts and for KCl-arrested hearts are 1.06 +/- 0.06 micromol x min(-1) x mg(-1) and 0.21 +/- 0.02 micromol x min(-1) x g(-1), respectively. The fraction of unlabeled acetate determined from the proton signal of the methyl group is small and essentially the same in beating and arrested hearts (7.4 +/- 1.7% and 8.8 +/- 2.1%, respectively). Thus, the large difference in the Glu C2/C4 between beating and arrested hearts is not due to the important contribution from anaplerotic sources in arrested hearts but simply to a substantial difference in citric acid cycle fluxes. Our model fits the experimental data well, indicating a fast exchange between 2-oxoglutarate and glutamate in the mitochondria of rat hearts. Analysis of the flux constant, calculated from the half-time of glutamate C4 labeling given in the literature, allows for a comparison of the citric acid flux for various working conditions in different animal species.

  10. Arachidonic Acid Metabolites Increased in Ulcerative Colitis Rats with Damp-heat Syndrome and were Down-regulated by Huanqin Decoction%花生四烯酸代谢物在湿热型溃疡性结肠炎大鼠的表达与调节

    Institute of Scientific and Technical Information of China (English)

    郑学宝; 戴世学; 邹颖

    2011-01-01

    Objective :To explore the role of arachidonic acid metabolites (AAMs) in ulcerative colitis (UC) rats with damp -heat syndrome (DHS), and to observe the effect of Huanqin decoction on the model. Methods: 45 rats were put into an artificial bioclimatic chamber with temperature of 36℃, humidity of 98% and feed in fat and sugar forage to establish the model for 4 weeks. After a one - week treatment by Huanqin decoction ( group H, n = 13) and by mesalazine (group M, n = 12), concentration of PGE2, LTB4, PAF and COX -2 in serum and colon were detected using ELISA.Triglycercide (TG) and T-cholesterol (CH) were also tested to reflect the degree of DHS, so were the fat globules in the feces. Histological scores for colon were rated through naked eyes to assess the severity of UC. Besides, the relations between the upper indexes were calculated by Pearson analysis. Results: Compared with the control group ( n = 15 ),PGE2, PAF, LTB4 and COX - 2 increased significantly in the model rats ( n = 12,P < 0.05 ). PGE2 and LTB4 in group H were obviously lower than that in group M, so were the TG, CH and feces fat globules(all P<0.05). But there was no statistical difference of the histological scores between group H and M. Pearson analysis showed there was a definited positive relationship between any two of PGE2,PAF,LTB4, COX -2, TG, CH, feces fat globules and histological scores (r > 0. 930, P < 0. 01 ). Conclsion: AAMs increased apparently in UC rats with DHS, which was closely related to the indexes involving both UC and damp - heat syndrome. It was proved to be more effective of Huangqin decoction to down -regulate PGE2, LTB4, TG, CH and and feces fat globules than mesalazine.%目的:探讨花生四烯酸(AA)代谢物在湿热型溃疡性结肠炎(UC)大鼠发病的作用以及黄芩汤的调节.方法:采用高脂高糖饲料结合人工气候箱法造成大鼠湿热,使用三硝基苯磺酸灌肠造成湿热型UC模型;将造模大鼠分为模型组(n=12)

  11. Carbon Flux Trapping: Highly Efficient Production of Polymer-Grade d-Lactic Acid with a Thermophilic d-Lactate Dehydrogenase.

    Science.gov (United States)

    Li, Chao; Tao, Fei; Xu, Ping

    2016-08-17

    High production of polymer-grade d-lactic acid is urgently required, particularly for the synthesis of polylactic acid. High-temperature fermentation has multiple advantages, such as lower equipment requirement and energy consumption, which are essential for lowering operating costs. We identified and introduced a unique d-lactate dehydrogenase into a thermotolerant butane-2,3-diol-producing strain. Carbon flux "trapping" was achieved by a "trapping point" created by combination of the introduced enzyme and the host efflux pump, which afforded irreversible transport of d-lactic acid. The overall carbon flux of the engineered strain was significantly enhanced and was redistributed predominantly to d-lactic acid. Under optimized conditions at 50 °C, d-lactic acid reached the highest titer (226.6 g L(-1) ) reported to date. This discovery allows us to extend the carbon flux trapping strategy to engineering complex metabolic networks. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Effect of sorbic acid doping on flux pinning in bulk MgB{sub 2} with the percolation model

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y. [Key Laboratory of Advanced Technologies of Materials (Ministry of Education of China), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Key Laboratory of Magnetic Levitation and Maglev Train (Ministry of Education of China), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Cheng, C.H. [School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia); Wang, L.; Sun, H.H. [Key Laboratory of Advanced Technologies of Materials (Ministry of Education of China), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Key Laboratory of Magnetic Levitation and Maglev Train (Ministry of Education of China), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Zhao, Y., E-mail: yzhao@swjtu.edu.c [Key Laboratory of Advanced Technologies of Materials (Ministry of Education of China), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Key Laboratory of Magnetic Levitation and Maglev Train (Ministry of Education of China), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); Superconductivity R and D Center (SRDC), Mail Stop 165, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China); School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia)

    2010-11-01

    In this paper, we study the doping effect of sorbic acid (C{sub 6}H{sub 8}O{sub 2}), from 0 to 20 wt.% of the total MgB{sub 2}, on critical temperature (T{sub c}), critical current density (J{sub c}), irreversibility field (H{sub irr}) and crystalline structure. The XRD patterns of samples show a slightly decrease in a-axis lattice parameter for doped samples, due to the partial substitution of carbon at boron site. On the other hand, we investigate the influence of doping on the behavior of flux pinning and J{sub c}(B) in the framework of percolation theory and it is found that the J{sub c}(B) behavior could be well fitted in high field region. The two key parameters, anisotropy and percolation threshold, play very important roles. It is believed that the enhancement of J{sub c} is due to the reduction of anisotropy in high field region.

  13. Chloride, gluconate, sulfate, and short-chain fatty acids affect calcium flux rates across the sheep forestomach epithelium.

    Science.gov (United States)

    Leonhard-Marek, S; Becker, G; Breves, G; Schröder, B

    2007-03-01

    In ruminants, more than 50% of overall gastrointestinal Ca absorption can occur preintestinally, and the anions of orally applied Ca salts are thought to play an important role in stimulating ruminal Ca absorption. This assumption is based mainly on ion-exchange studies that have used gluconate as the control anion, which may bind Ca2+ ions and interfere with treatment effects. In the present study, we investigated the distinct effects of different anions on Ca absorption across the sheep rumen and on the concentration of free Ca2+ ions ([Ca2+]ion). We showed that gluconate, sulfate, and short-chain fatty acids (SCFA) remarkably reduced [Ca2+]ion in buffer solutions. Nevertheless, increasing the Cl or SCFA concentration by 60 mM stimulated net ruminal Ca absorption 5- to 7-fold, but these effects could be antagonized by gluconate. Therefore, ion-exchange experiments must be (re)evaluated very carefully, because changes in [Ca2+]ion in the presence of gluconate, sulfate, or SCFA not only might entail an underestimation of Ca flux rates, but also might have effects on other cellular pathways that are Ca2+ dependent. Concerning the optimal Ca supply for dairy cows, the present study suggests that CaCl2 formulations and Ca salts of the SCFA stimulate Ca absorption across the rumen wall and are beneficial in preventing or correcting a Ca deficiency.

  14. Bile acid flux through portal but not peripheral veins inhibits CYP7A1 expression without involvement of ileal FGF19 in rabbits.

    Science.gov (United States)

    Shang, Quan; Guo, Grace L; Honda, Akira; Shi, Daniel; Saumoy, Monica; Salen, Gerald; Xu, Guorong

    2014-08-15

    It was proposed that CYP7A1 expression is suppressed through the gut-hepatic signaling pathway fibroblast growth factor (FGF) 15/19-fibroblast growth factor receptor 4, which is initiated by activation of farnesoid X receptor in the intestine rather than in the liver. The present study tested whether portal bile acid flux alone without ileal FGF19 could downregulate CYP7A1 expression in rabbits. A rabbit model was developed by infusing glycodeoxycholic acid (GDCA) through the splenic vein to bypass ileal FGF19. Study was conducted in four groups of rabbits: control; bile fistula + bovine serum albumin solution perfusion (BF); BF + GDCA (by portal perfusion); and BF + GDCA-f (by femoral perfusion). Compared with only BF, BF + GDCA (6 h portal perfusion) suppressed CYP7A1 mRNA, whereas BF + GDCA-f (via femoral vein) with the same perfusion rate of GDCA did not show inhibitory effects. Meanwhile, there was a decrease in ileal FGF19 expression and portal FGF19 protein levels, but an equivalent increase in biliary bile acid outputs in both GDCA perfusion groups. This study demonstrated that portal bile acid flux alone downregulated CYP7A1 expression with diminished FGF19 expression and protein levels, whereas the same bile acid flux reaching the liver through the hepatic artery via femoral vein had no inhibitory effect on CYP7A1. We propose that bile acid flux through the portal venous system may be a kind of "intestinal factor" that suppresses CYP7A1 expression.

  15. Metabolic flux rearrangement in the amino acid metabolism reduces ammonia stress in the α1-antitrypsin producing human AGE1.HN cell line.

    Science.gov (United States)

    Priesnitz, Christian; Niklas, Jens; Rose, Thomas; Sandig, Volker; Heinzle, Elmar

    2012-03-01

    This study focused on metabolic changes in the neuronal human cell line AGE1.HN upon increased ammonia stress. Batch cultivations of α(1)-antitrypsin (A1AT) producing AGE1.HN cells were carried out in media with initial ammonia concentrations ranging from 0mM to 5mM. Growth, A1AT production, metabolite dynamics and finally metabolic fluxes calculated by metabolite balancing were compared. Growth and A1AT production decreased with increasing ammonia concentration. The maximum A1AT concentration decreased from 0.63g/l to 0.51g/l. Central energy metabolism remained relatively unaffected exhibiting only slightly increased glycolytic flux at high initial ammonia concentration in the medium. However, the amino acid metabolism was significantly changed. Fluxes through transaminases involved in amino acid degradation were reduced concurrently with a reduced uptake of amino acids. On the other hand fluxes through transaminases working in the direction of amino acid synthesis, i.e., alanine and phosphoserine, were increased leading to increased storage of excess nitrogen in extracellular alanine and serine. Glutamate dehydrogenase flux was reversed increasingly fixing free ammonia with increasing ammonia concentration. Urea production additionally observed was associated with arginine uptake by the cells and did not increase at high ammonia stress. It was therefore not used as nitrogen sink to remove excess ammonia. The results indicate that the AGE1.HN cell line can adapt to ammonia concentrations usually present during the cultivation process to a large extent by changing metabolism but with slightly reduced A1AT production and growth.

  16. Comparison of arachidonate metabolism by alveolar macrophages from bighorn and domestic sheep.

    Science.gov (United States)

    Silflow, R M; Foreyt, W J; Taylor, S M; Laegreid, W W; Liggitt, H D; Leid, R W

    1991-02-01

    We have defined the metabolites of arachidonic acid (AA) secreted by alveolar macrophages (AMs) of bighorn sheep and domestic sheep in response to three agents: calcium ionophore A23187, phorbol myristate acetate (PMA), and opsonized zymosan. Cells were labeled with [3H]AA prior to stimulation and 11 tritiated metabolites, including prostaglandins (PGs), thromboxanes (TXs), leukotrienes (LTs), and hydroxyeicosatetraenoic acids (HETEs), were detected and quantitated by high-performance liquid chromotography and radiometry. Zymosan stimulation resulted in the release of significantly elevated quantities (P less than 0.05), of LTB4, [5(S), 12(R)-dihydroxy-6,14-cis-8,10-trans-eicosatetraenoic acid], 5-HETE, [5(S)-hydroxyeicosatetraenoic acid], and the nonenzymatic isomers of LTB4, [LTB I, 5(S),12(R)-6-trans-LTB4] and LTB II, [5(S), 12(S)-6-trans-LTB4], from domestic sheep AM when compared to bighorn sheep AM. Phorbol myristate acetate (PMA) stimulation released significantly elevated quantities (P less than 0.04), of TXB2, (thromboxane B2), HHT, [12(S)-12-hydroxy-5,8,10-heptadecaenoic acid], LTB I, LTB II, and 15-HETE, [15(S)-hydroxyeicosatetraenoic acid] from domestic sheep AMs when compared to bighorn sheep AMs. However, after A23187 challenge, only 15-HETE was significantly elevated (P less than 0.04) in domestic sheep AMs when compared to bighorn sheep AMs. These clear differences in AA metabolism of AMs obtained from bighorn and domestic sheep in response to three different agonists suggest not only different control mechanisms for lung metabolism of AA in the two species, but also suggest that differences in the metabolites released may lead to quite different regulation of lung defense mechanisms in the two sheep species.

  17. Mathematical models for determining metabolic fluxes through the citric acid and the glyoxylate cycles in Saccharomyces cerevisiae by 13C-NMR spectroscopy.

    Science.gov (United States)

    Tran-Dinh, S; Bouet, F; Huynh, Q T; Herve, M

    1996-12-15

    We propose, first, a practical method for studying the isotopic transformation of glutamate or any other metabolite isotopomers in the citric acid and the glyoxylate cycles; second, two mathematical models, one for evaluating the flux through the citric acid cycle and the other for evaluating the flux through the latter coupled to the glyoxylate cycle in yeast. These models are based on the analysis of 13C-NMR spectra of glutamate obtained from Saccharomyces cerevisiae, NCYC strain, fed with 100% enriched [2-13C]acetate. The population of each glutamate isotopomer, the change in intensity of each multiplet component or the enrichment of any glutamate carbon is expressed by a specific analytical equation from which the flux in the citric acid and the glyoxylate cycles can be deduced. The aerobic metabolism of 100% [2-13C]acetate in acetate-grown S. cerevisiae cells was studied as a function of time using 13C-NMR. 1H-NMR and biochemical techniques. The C1 and C6 doublet and singlet of labeled trehalose increase continuously with time indicating that there is no isotopic transformation between trehalose isotopomers even though the corresponding formation rates are different. By contrast, the glutamate C4 singlet increases then decreases with time. The C4 doublet, which is lower than the singlet for t 90 min. A similar observation was made for the C2 resonance singlet and doublet. In addition, the glutamate C2 multiplet consists of only seven instead of nine peaks as in random labeling. These results agree well with our models and demonstrate that, in the presence of acetate, anaplerotic carbon sources involved in the synthesis of acetyl-CoA are negligible in yeast. The flux in the citric acid cycle was deduced from a plot of the C4 area versus incubation time, while the flux within the glyoxylate cycle was determined from the relative intensity of the glutamate C4 doublet and singlet. The fluxes in the citric acid and the glyoxylate cycles were found to be comparable

  18. Acid soldering flux poisoning

    Science.gov (United States)

    ... Throat swelling (which may also cause breathing difficulty) SKIN Burn Holes in the skin or tissues under the skin Irritation ... tracing) Endoscopy -- camera down the throat to see burns in the ... burned skin Washing of the skin (irrigation), perhaps every few ...

  19. Solder Flux Residues and Humidity-Related Failures in Electronics: Relative Effects of Weak Organic Acids Used in No-Clean Flux Systems

    DEFF Research Database (Denmark)

    Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

    2015-01-01

    (RH) to ∼99%RH at 25°C. The following parameters were used for characterization of WOAs: mass gain due to water adsorption and deliquescence of the WOA (by quartz crystal microbalance), resistivity of the water layer formed on the printed circuit board (by impedance spectroscopy), and leakage current...... measured using the surface insulation resistance pattern in the potential range from 0 V to 10 V. The combined results indicate the importance of the WOA chemical structure for the water adsorption and therefore conductive water layer formation on the printed circuit board assembly (PCBA). A substantial...... increase of leakage currents and probability of electrochemical migration was observed at humidity levels above the RH corresponding to the deliquescence point of WOAs present as contaminants on the printed circuit boards. The results suggest that use of solder fluxes with WOAs having higher deliquescence...

  20. Mechanism of cAMP-induced H+ -efflux of Dictyostelium cells: a role for fatty acids

    Indian Academy of Sciences (India)

    H Flaadt; R Schaloske; D Malchow

    2000-09-01

    Aggregating Dictyostelium cells release protons when stimulated with cAMP. To find out whether the protons are generated by acidic vesicles or in the cytosol, we permeabilized the cells and found that this did not alter the cAMP-response. Proton efflux in intact cells was inhibited by preincubation with the V-type H+ ATPase inhibitor concanamycin A and with the plasma membrane H+ ATPase blocker miconazole. Surprisingly, miconazole also inhibited efflux in permeabilized cells, indicating that this type of H+ ATPase is present on intracellular vesicles as well. Vesicular acidification was inhibited by miconazole and by concanamycin A, suggesting that the acidic vesicles contain both V-type and P-type H+ ATPases. Moreover, concanamycin A and miconazole acted in concert, both in intact cells and in vesicles. The mechanism of cAMP-induced Ca2+-fluxes involves phospholipase A2 activity. Fatty acids circumvent the plasma membrane and stimulate vesicular Ca2+-efflux. Here we show that arachidonic acid elicited H+-efflux not only from intact cells but also from acidic vesicles. The target of regulation by arachidonic acid seemed to be the vesicular Ca2+-relase channel.

  1. Combined Flux Chamber and Genomics Approach Links Nitrous Acid Emissions to Ammonia Oxidizing Bacteria and Archaea in Urban and Agricultural Soil.

    Science.gov (United States)

    Scharko, Nicole K; Schütte, Ursel M E; Berke, Andrew E; Banina, Lauren; Peel, Hannah R; Donaldson, Melissa A; Hemmerich, Chris; White, Jeffrey R; Raff, Jonathan D

    2015-12-01

    Nitrous acid (HONO) is a photochemical source of hydroxyl radical and nitric oxide in the atmosphere that stems from abiotic and biogenic processes, including the activity of ammonia-oxidizing soil microbes. HONO fluxes were measured from agricultural and urban soil in mesocosm studies aimed at characterizing biogenic sources and linking them to indigenous microbial consortia. Fluxes of HONO from agricultural and urban soil were suppressed by addition of a nitrification inhibitor and enhanced by amendment with ammonium (NH4(+)), with peaks at 19 and 8 ng m(-2) s(-1), respectively. In addition, both agricultural and urban soils were observed to convert (15)NH4(+) to HO(15)NO. Genomic surveys of soil samples revealed that 1.5-6% of total expressed 16S rRNA sequences detected belonged to known ammonia oxidizing bacteria and archaea. Peak fluxes of HONO were directly related to the abundance of ammonia-oxidizer sequences, which in turn depended on soil pH. Peak HONO fluxes under fertilized conditions are comparable in magnitude to fluxes reported during field campaigns. The results suggest that biogenic HONO emissions will be important in soil environments that exhibit high nitrification rates (e.g., agricultural soil) although the widespread occurrence of ammonia oxidizers implies that biogenic HONO emissions are also possible in the urban and remote environment.

  2. Impaired cytosolic NADH shuttling and elevated UCP3 contribute to inefficient citric acid cycle flux support of postischemic cardiac work in diabetic hearts.

    Science.gov (United States)

    Banke, Natasha H; Lewandowski, E Douglas

    2015-02-01

    Diabetic hearts are subject to more extensive ischemia/reperfusion (ISC/REP) damage. This study examined the efficiency of citric acid cycle (CAC) flux and the transfer of cytosolic reducing equivalents into the mitochondria for oxidative support of cardiac work following ISC/REP in hearts of c57bl/6 (NORM) and type 2 diabetic, db/db mouse hearts. Flux through the CAC and malate-aspartate shuttle (MA) were monitored via dynamic (13)C NMR of isolated hearts perfused with (13)C palmitate+glucose. MA flux was lower in db/db than NORM. Oxoglutarate malate carrier (OMC) was elevated in the db/db heart, suggesting a compensatory response to low NADHc. Baseline CAC flux per unit work (rate-pressure-product, RPP) was similar between NORM and db/db, but ISC/REP reduced the efficiency of CAC flux/RPP by 20% in db/db. ISC/REP also increased UCP3 transcription, indicating potential for greater uncoupling. Therefore, ISC/REP induces inefficient carbon utilization through the CAC in hearts of diabetic mice due to the combined inefficiencies in NADHc transfer per OMC content and increased uncoupling via UCP3. Ischemia and reperfusion exacerbated pre-existing mitochondrial defects and metabolic limitations in the cytosol of diabetic hearts. These limitations and defects render diabetic hearts more susceptible to inefficient carbon fuel utilization for oxidative energy metabolism. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Carboxylic Acid Ionophores as Probes of the Role of Calcium in Biological Systems

    Science.gov (United States)

    Reed, P. W.

    1983-01-01

    The biological effects of calcium ionophores are described, focusing on arachidonic acid oxygenation, and the formation of a number of oxygenated metabolites of arachidonic acid. These metabolites are involved in a number of bodily functions, and their production may be regulated by calcium.

  4. Flux control exerted by mitochondrial outer membrane carnitine palmitoyltransferase over beta-oxidation, ketogenesis and tricarboxylic acid cycle activity in hepatocytes isolated from rats in different metabolic states.

    Science.gov (United States)

    Drynan, L; Quant, P A; Zammit, V A

    1996-08-01

    The Flux Control Coefficients of mitochondrial outer membrane carnitine palmitoyltransferase (CPT I) with respect to the overall rates of beta-oxidation, ketogenesis and tricarboxylic acid cycle activity were measured in hepatocytes isolated from rats in different metabolic states (fed, 24 h-starved, starved-refed and starved/insulin-treated). These conditions were chosen because there is controversy as to whether, when significant control ceases to be exerted by CPT I over the rate of fatty oxidation [Moir and Zammit (1994) Trends Biochem. Sci. 19, 313-317], this is transferred to one or more steps proximal to acylcarnitine synthesis (e.g. decreased delivery of fatty acids to the liver) or to the reaction catalysed by mitochondrial 3-hydroxy-3-methyl-glutaryl-CoA synthase [Hegardt (1995) Biochem. Soc. Trans. 23, 486-490]. Therefore isolated hepatocytes were used in the present study to exclude the involvement of changes in the rate of delivery of non-esterified fatty acids (NEFA) to the liver, such as occur in vivo, and to ascertain whether, under conditions of constant supply of NEFA, CPT I retains control over the relevant fluxes of fatty acid oxidation to ketones and carbon dioxide, or whether control is transferred to another (intrahepatocytic) site. The results clearly show that the Flux Control Coefficients of CPT I with respect to overall beta-oxidation and ketogenesis are very high under all conditions investigated, indicating that control is not lost to another intrahepatic site during the metabolic transitions studied. The control of CPT I over tricarboxylic acid cycle activity was always very low. The significance of these findings for the integration of fatty acid and carbohydrate metabolism in the liver is discussed.

  5. Pancreatic islet function in omega-3 fatty acid-depleted rats : Alteration of calcium fluxes and calcium-dependent insulin release

    OpenAIRE

    Zhang, Ying; Oguzhan, Berrin; Louchami, Karim; Chardigny, Jean-Michel; Portois, Laurence; Carpentier, Yvon; Malaisse, Willy-Jean; Herchuelz, André; Sener, Abdullah

    2006-01-01

    Considering the insufficient supply of long-chain polyunsaturated omega-3 fatty acids often prevailing in Western populations, this report deals mainly with alterations of Ca2+ fluxes and Ca2+-dependent insulin secretory events in isolated pancreatic islets from omega-3-depleted rats. In terms of Ca-45(2+) handling, the islets from omega-3-depleted rats, compared with those from normal animals, displayed an unaltered responsiveness to an increase in extracellular K+ concentration, a lower inf...

  6. 13C-NMR spectroscopic evaluation of the citric acid cycle flux in conditions of high aspartate transaminase activity in glucose-perfused rat hearts.

    Science.gov (United States)

    Tran-Dinh, S; Hoerter, J A; Mateo, P; Gyppaz, F; Herve, M

    1998-12-01

    A new mathematical model, based on the observation of 13C-NMR spectra of two principal metabolites (glutamate and aspartate), was constructed to determine the citric acid cycle flux in the case of high aspartate transaminase activity leading to the formation of large amounts of labeled aspartate and glutamate. In this model, the labeling of glutamate and aspartate carbons by chemical and isotopic exchange with the citric acid cycle are considered to be interdependent. With [U-13C]Glc or [1,2-(13)C]acetate as a substrate, all glutamate and aspartate carbons can be labeled. The isotopic transformations of 32 glutamate isotopomers into 16 aspartate isotopomers or vice versa were studied using matrix operations; the results were compiled in two matrices. We showed how the flux constants of the citric acid cycle and the 13C-enrichment of acetyl-CoA can be deduced from 13C-NMR spectra of glutamate and/or aspartate. The citric acid cycle flux in beating Wistar rat hearts, aerobically perfused with [U-13C]glucose in the absence of insulin, was investigated by 13C-NMR spectroscopy. Surprisingly, aspartate instead of glutamate was found to be the most abundantly-labeled metabolite, indicating that aspartate transaminase (which catalyses the reversible reaction: (glutamate + oxaloacetate 2-oxoglutarate + aspartate) is highly active in the absence of insulin. The amount of aspartate was about two times larger than glutamate. The quantities of glutamate (G0) or aspartate (A0) were approximately the same for all hearts and remained constant during perfusion: G0 = (0.74 +/- 0.03) micromol/g; A0 = (1.49 +/- 0.05) micromol/g. The flux constants, i.e., the fraction of glutamate and aspartate in exchange with the citric acid cycle, were about 1.45 min(-1) and 0.72 min(-1), respectively; the flux of this cycle is about (1.07 +/- 0.02) micromol min(-1) g(-1). Excellent agreement between the computed and experimental data was obtained, showing that: i) in the absence of insulin, only 41

  7. Abscisic acid flux alterations result in differential abscisic acid signaling responses and impact assimilation efficiency in barley under terminal drought stress.

    Science.gov (United States)

    Seiler, Christiane; Harshavardhan, Vokkaliga T; Reddy, Palakolanu S; Hensel, Götz; Kumlehn, Jochen; Eschen-Lippold, Lennart; Rajesh, Kalladan; Korzun, Viktor; Wobus, Ulrich; Lee, Justin; Selvaraj, Gopalan; Sreenivasulu, Nese

    2014-04-01

    Abscisic acid (ABA) is a central player in plant responses to drought stress. How variable levels of ABA under short-term versus long-term drought stress impact assimilation and growth in crops is unclear. We addressed this through comparative analysis, using two elite breeding lines of barley (Hordeum vulgare) that show senescence or stay-green phenotype under terminal drought stress and by making use of transgenic barley lines that express Arabidopsis (Arabidopsis thaliana) 9-cis-epoxycarotenoid dioxygenase (AtNCED6) coding sequence or an RNA interference (RNAi) sequence of ABA 8'-hydroxylase under the control of a drought-inducible barley promoter. The high levels of ABA and its catabolites in the senescing breeding line under long-term stress were detrimental for assimilate productivity, whereas these levels were not perturbed in the stay-green type that performed better. In transgenic barley, drought-inducible AtNCED expression afforded temporal control in ABA levels such that the ABA levels rose sooner than in wild-type plants but also subsided, unlike as in the wild type , to near-basal levels upon prolonged stress treatment due to down-regulation of endogenous HvNCED genes. Suppressing of ABA catabolism with the RNA interference approach of ABA 8'-hydroxylase caused ABA flux during the entire period of stress. These transgenic plants performed better than the wild type under stress to maintain a favorable instantaneous water use efficiency and better assimilation. Gene expression analysis, protein structural modeling, and protein-protein interaction analyses of the members of the PYRABACTIN RESISTANCE1/PYRABACTIN RESISTANCE1-LIKE/REGULATORY COMPONENT OF ABA RECEPTORS, TYPE 2C PROTEIN PHOSPHATASE Sucrose non-fermenting1-related protein kinase2, and ABA-INSENSITIVE5/ABA-responsive element binding factor family identified specific members that could potentially impact ABA metabolism and stress adaptation in barley.

  8. Regulation of adipose branched-chain amino acid catabolism enzyme expression and cross-adipose amino acid flux in human obesity.

    Science.gov (United States)

    Lackey, Denise E; Lynch, Christopher J; Olson, Kristine C; Mostaedi, Rouzbeh; Ali, Mohamed; Smith, William H; Karpe, Fredrik; Humphreys, Sandy; Bedinger, Daniel H; Dunn, Tamara N; Thomas, Anthony P; Oort, Pieter J; Kieffer, Dorothy A; Amin, Rajesh; Bettaieb, Ahmed; Haj, Fawaz G; Permana, Paska; Anthony, Tracy G; Adams, Sean H

    2013-06-01

    Elevated blood branched-chain amino acids (BCAA) are often associated with insulin resistance and type 2 diabetes, which might result from a reduced cellular utilization and/or incomplete BCAA oxidation. White adipose tissue (WAT) has become appreciated as a potential player in whole body BCAA metabolism. We tested if expression of the mitochondrial BCAA oxidation checkpoint, branched-chain α-ketoacid dehydrogenase (BCKD) complex, is reduced in obese WAT and regulated by metabolic signals. WAT BCKD protein (E1α subunit) was significantly reduced by 35-50% in various obesity models (fa/fa rats, db/db mice, diet-induced obese mice), and BCKD component transcripts significantly lower in subcutaneous (SC) adipocytes from obese vs. lean Pima Indians. Treatment of 3T3-L1 adipocytes or mice with peroxisome proliferator-activated receptor-γ agonists increased WAT BCAA catabolism enzyme mRNAs, whereas the nonmetabolizable glucose analog 2-deoxy-d-glucose had the opposite effect. The results support the hypothesis that suboptimal insulin action and/or perturbed metabolic signals in WAT, as would be seen with insulin resistance/type 2 diabetes, could impair WAT BCAA utilization. However, cross-tissue flux studies comparing lean vs. insulin-sensitive or insulin-resistant obese subjects revealed an unexpected negligible uptake of BCAA from human abdominal SC WAT. This suggests that SC WAT may not be an important contributor to blood BCAA phenotypes associated with insulin resistance in the overnight-fasted state. mRNA abundances for BCAA catabolic enzymes were markedly reduced in omental (but not SC) WAT of obese persons with metabolic syndrome compared with weight-matched healthy obese subjects, raising the possibility that visceral WAT contributes to the BCAA metabolic phenotype of metabolically compromised individuals.

  9. Niflumic acid modulates uncoupled substrate-gated conductances in the human glutamate transporter EAAT4.

    Science.gov (United States)

    Poulsen, M V; Vandenberg, R J

    2001-07-01

    1. The effects of niflumic acid on the substrate-gated currents mediated by the glutamate transporter EAAT4 expressed in Xenopus laevis oocytes were examined using radiolabelled substrate flux measurements and two-electrode voltage clamp techniques. 2. Niflumic acid significantly enhanced the substrate-gated currents in EAAT4, without affecting the affinity of the substrates towards EAAT4. At a concentration of 300 microM, niflumic acid caused a 19 +/- 5 % reduction in L-[(3)H]glutamate uptake and no significant effect on the uptake of DL-[(3)H]aspartate. Thus, enhancement of the substrate-gated currents in EAAT4 does not correlate with the rate of substrate transport and suggests that the niflumic acid-induced currents are not thermodynamically coupled to the transport of substrate. 3. Niflumic acid and arachidonic acid co-applied with substrate to EAAT4-expressing oocytes had similar functional consequences. However, niflumic acid still enhanced the L-glutamate-gated current to the same extent in the presence and absence of a saturating dose of arachidonic acid, which suggests that the sites of action of the two compounds are distinct. 4. The EAAT4-mediated currents for the two substrates, L-glutamate and L-aspartate, were not enhanced equally by addition of the same dose of niflumic acid and the ionic composition of the niflumic acid-induced currents was not the same for the two substrates. Protons carry the L-glutamate-gated niflumic acid-induced current and both protons and chloride ions carry the L-aspartate-gated niflumic acid-induced current. 5. These results show that niflumic acid can be used to probe the functional aspects of EAAT4 and that niflumic acid and other non-steroid anti-inflammatory drugs could be used as the basis for the development of novel modulators of glutamate transporters.

  10. Fatty acid fouling of forward osmosis membrane: Effects of pH, calcium, membrane orientation, initial permeate flux and foulant composition.

    Science.gov (United States)

    Zhao, Pin; Gao, Baoyu; Yue, Qinyan; Liu, Pan; Shon, Ho Kyong

    2016-08-01

    Octanoic acid (OA) was selected to represent fatty acids in effluent organic matter (EOM). The effects of feed solution (FS) properties, membrane orientation and initial permeate flux on OA fouling in forward osmosis (FO) were investigated. The undissociated OA formed a cake layer quickly and caused the water flux to decline significantly in the initial 0.5hr at unadjusted pH3.56; while the fully dissociated OA behaved as an anionic surfactant and promoted the water permeation at an elevated pH of 9.00. Moreover, except at the initial stage, the sudden decline of water flux (meaning the occurrence of severe membrane fouling) occurred in two conditions: 1. 0.5mmol/L Ca(2+), active layer facing draw solution (AL-DS) and 1.5mol/L NaCl (DS); 2. No Ca(2+), active layer-facing FS (AL-FS) and 4mol/L NaCl (DS). This demonstrated that cake layer compaction or pore blocking occurred only when enough foulants were absorbed into the membrane surface, and the water permeation was high enough to compact the deposit inside the porous substrate. Furthermore, bovine serum albumin (BSA) was selected as a co-foulant. The water flux of both co-foulants was between the fluxes obtained separately for the two foulants at pH3.56, and larger than the two values at pH9.00. This manifested that, at pH3.56, BSA alleviated the effect of the cake layer caused by OA, and OA enhanced BSA fouling simultaneously; while at pH9.00, the mutual effects of OA and BSA eased the membrane fouling.

  11. Effects of ω-3 polyunsaturated fatty acids on prostaglandin E-2 and arachidonic acid in rats with senile dementia%ω-3多不饱和脂肪酸对老年痴呆大鼠前列腺素E2、花生四烯酸的影响

    Institute of Scientific and Technical Information of China (English)

    赵秀娟; 冯亚青; 李文景; 刘月欣; 张振凤; 吕佩源

    2009-01-01

    Objective To investigate the mechanism of ω-3 polyunsaturated fatty acids in senile dementi-a. Methods The normal 15 months old Wistar rats were randomly divided into normal control,model group andre-cape latency time and mistaken times were evaluated by using the step down test. The content of serum PGE2 and urachidonic acid(AA),EPA and DHA of cerebral tissue in rats were detected. Results The lingeringly latency and error times were ( 264.83±16.99) s and (4.8±1.7) times in control group, ( 189.26±31.42)s and ( 9.6± 2.2) times in model group, (230.88±29.35) s and (7.3±2.2) times in treatment group, respectively. Differences in three groups were very significantly by analyses of variance(F=20.114, F=13.638, P=0.000). Compared with model group, control group and treatment group had lingeringly latency(LSD-t=6.332,P=0.000 and LSD-t =3.987, P=0.002, respectively) and less error times (LSD-t=5.221, P=0.000 and LSD-t=3.502, P= 0.019,respectively). Serum PGE2 were in control group, model group and treatment group were very significantly by analyses of variance(F=6.851 , P=0.004). Compared with model group,control group had less serum PGE2 (LSD-t=3.684, P=0.001 ). Compared with model group,ω-3 polyunsaturated fatty acids chould decrease serum PGE2( LSD-t=2.152, P=0.041 ). AA, EPA and DHA of cerebral tissue in control group, in model group, in treatment group, respectively. Differences in three groups were very significantly by analyses of variance (F=5.538, P=0.010, F=4.240, P=0.025, F=4.633, P=0.019). Compared with model group,ω-3 polyunsaturat-ed fatty acids could decrease A A(LSD-t=2.273, P=0.031) and increase EPA and D HA (LSD-t=2.428, P= 0.022,LSD-t=2.520, P=0.018,respectively). Conclusions ω-3 polyunsaturated fatty acids can improve learning-memory function in rats,change the proportion of AA,EPA and DHA in cerebral tissue and prevent senile dementia.%目的 探讨ω-3多不饱和脂肪酸治疗老年痴呆的可能机制.方法 将15月龄雌性健

  12. Essential fatty acid nutrition of the American alligator (Alligator mississippiensis).

    Science.gov (United States)

    Staton, M A; Edwards, H M; Brisbin, I L; Joanen, T; McNease, L

    1990-07-01

    The essential fatty acid (EFA) nutrition of young American alligators (Alligator mississippiensis) was examined by feeding a variety of fats/oils with potential EFA activity. Over a 12-wk period, alligators fed diets containing 2.5 or 5.0% chicken liver oil grew longer and heavier and converted feed to body mass more efficiently than alligators fed other fat/oil combinations that lacked or contained only trace amounts of arachidonic acid [20:4(n-6)]. Alligators fed an EFA-deficient diet (containing only coconut fat as the dietary fat) were the slowest-growing animals and converted feed to body mass least efficiently. However, over a 41-wk feeding period, alligators fed this diet showed no obvious external signs of deficiency other than being reduced in size and unthrifty. Fatty acid composition of heart, liver, muscle, skin and adipose tissue lipids was influenced markedly by dietary fat composition. Tissues varied significantly in response to dietary fat composition. Heart lipids contained the lowest levels of short- and medium-chain fatty acids and the highest levels of arachidonic acid. Arachidonic acid levels were less influenced by diet than were levels of other 20- and 22-carbon polyunsaturated fatty acids. Radiotracer studies indicated that linoleic acid was converted to arachidonic acid in the liver. Nevertheless, tissue arachidonic acid levels also appeared to be maintained by concentration from dietary sources and selective conservation. It appears that a dietary source of arachidonic acid may be required for a maximum rate of growth.

  13. Oral gold compound auranofin triggers arachidonate release and cyclooxygenase metabolism in the alveolar macrophage

    Energy Technology Data Exchange (ETDEWEB)

    Peters-Golden, M.; Shelly, C.

    1988-12-01

    We examined the effect of in vitro incubation with the oral gold compound auranofin (AF) on arachidonic acid (AA) release and metabolism by rat alveolar macrophages (AMs). AF stimulated dose- and time-dependent release of /sup 14/C-AA from prelabeled AMs, which reached 4.7 +/- 0.3% (mean +/- SEM) of incorporated radioactivity at 10 micrograms/ml for 90 min, as compared to 0.5 +/- 0.1% release following control incubation for 90 min (p less than 0.001). Similar dose- and time-dependent synthesis of thromboxane (Tx) A2 (measured as TxB2) and prostaglandin (PG) E2 was demonstrated by radioimmunoassay of medium from unlabeled cultures, reaching 18-fold and 9-fold, respectively, of the control values at 10 micrograms/ml AF for 90 min (p less than 0.001 for both). AF-induced TxB2 and PGE2 synthesis was inhibited by indomethacin as well as by pretreatment with methylprednisolone. No increase in the synthesis of immunoreactive leukotrienes (LT) B4 or C4 was noted at any dose or time of AF. High performance liquid chromatographic separation of /sup 14/C-eicosanoids synthesized by prelabeled AMs confirmed that AF induced the release of free AA and its metabolism to cyclooxygenase, but not 5-lipoxygenase, metabolites. The ability of AF to trigger macrophage AA metabolism may be relevant to the exacerbation of certain inflammatory processes which sometimes accompany gold therapy.

  14. Effects of the sintering temperature on the flux-pinning mechanism and the activation energy of malic-acid doped MgB2

    Directory of Open Access Journals (Sweden)

    J Peleckis

    2012-12-01

    Full Text Available   The flux-pinning mechanism and activation energy of 10 wt % malic acid-doped MgB2 were investigated by measuring of the critical current density and resistivity as a function of magnetic field and temperature. A crossover field, Bsb, was observed from the single vortex to the small vortex bundle pinning regime. For the sintered sample, the temperature dependence of Bsb(T at low temperature is in good agreement with the δℓ pinning mechanism, i.e., pinning associated with charge-carrier mean free path fluctuation. The activation energy was decreased by increasing the magnetic field and increased by increasing sintering temperature.

  15. The European Food Safety Authority recommendation for polyunsaturated fatty acid composition of infant formula overrules breast milk, puts infants at risk, and should be revised.

    Science.gov (United States)

    Crawford, Michael A; Wang, Yiqun; Forsyth, Stewart; Brenna, J Thomas

    2015-12-01

    The European Food Safety Authority (EFSA) has concluded from a limited review of the literature that although docosahexaenoic acid (DHA) is required for infant formula, arachidonic acid is not required "even in the presence of DHA" (EFSA Journal, 12 (2014) 3760). This flawed opinion is grounded in human trials which tested functionality of DHA in neural outcomes and included arachidonic acid ostensibly to support growth. The EFSA report mistakes a nutrient ubiquitous in the diets of newborn infants, through breast milk and with wide-ranging health and neurodevelopmental effects, for an optional drug targeted to a particular outcome that is properly excluded when no benefit is found for that particular outcome. Arachidonic acid has very different biological functions compared to DHA, for example, arachidonic acid has unique functions in the vasculature and in specific aspects of immunity. Indeed, the overwhelming majority of trials include both DHA and arachidonic acid, and test development specific to DHA such as neural and visual development. DHA suppresses membrane arachidonic acid concentrations and its function. An infant formula with DHA and no arachidonic acid runs the risk of cardio and cerebrovascular morbidity and even mortality through suppression of the favorable oxylipin derivatives of arachidonic acid. The EFSA recommendation overruling breast milk composition should be revised forthwith, otherwise being unsafe, ungrounded in most of the evidence, and risking lifelong disability.

  16. Toxicological evaluation of arachidonic acid (ARA)-rich oil and docosahexaenoic acid (DHA)-rich oil.

    Science.gov (United States)

    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.

  17. Improvement effect on corrosion under heat flux in nitric acid solutions of anti-IGC stainless steel and high Cr-W-Si Ni base RW alloy

    Energy Technology Data Exchange (ETDEWEB)

    Doi, Masamitsu; Kiuchi, Kiyoshi; Yano, Masaya; Sekiyama, Yoshio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-03-01

    In the advanced purex reprocessing equipment, the higher corrosion resistance is required for materials because of the high corrosive environment caused from the thermodynamic decomposition of boiling nitric acid. The authors group has been developed the two types of new corrosion resistant materials for application to the reprocessing equipment. One is the type 304ULC stainless steel with controlled microstructure and decreased minor elements (EB-SAR). The other is the nickel base alloy with the ability of forming stable oxide film by addition of Cr, W and Si (RW alloy). In this study, the heat transfer tubes applied in diminished pressure was postulated. In addition to the dominant factors of heat conducting corrosion by the nitric acid solution, the effect of the heat flux and the concentration of the corrosive vanadium ions were investigated. (author)

  18. The short-chain fatty acid uptake fluxes by mice on a guar gum supplemented diet associate with amelioration of major biomarkers of the metabolic syndrome.

    Science.gov (United States)

    den Besten, Gijs; Havinga, Rick; Bleeker, Aycha; Rao, Shodhan; Gerding, Albert; van Eunen, Karen; Groen, Albert K; Reijngoud, Dirk-Jan; Bakker, Barbara M

    2014-01-01

    Studies with dietary supplementation of various types of fibers have shown beneficial effects on symptoms of the metabolic syndrome. Short-chain fatty acids (SCFAs), the main products of intestinal bacterial fermentation of dietary fiber, have been suggested to play a key role. Whether the concentration of SCFAs or their metabolism drives these beneficial effects is not yet clear. In this study we investigated the SCFA concentrations and in vivo host uptake fluxes in the absence or presence of the dietary fiber guar gum. C57Bl/6J mice were fed a high-fat diet supplemented with 0%, 5%, 7.5% or 10% of the fiber guar gum. To determine the effect on SCFA metabolism, 13C-labeled acetate, propionate or butyrate were infused into the cecum of mice for 6 h and the isotopic enrichment of cecal SCFAs was measured. The in vivo production, uptake and bacterial interconversion of acetate, propionate and butyrate were calculated by combining the data from the three infusion experiments in a single steady-state isotope model. Guar gum treatment decreased markers of the metabolic syndrome (body weight, adipose weight, triglycerides, glucose and insulin levels and HOMA-IR) in a dose-dependent manner. In addition, hepatic mRNA expression of genes involved in gluconeogenesis and fatty acid synthesis decreased dose-dependently by guar gum treatment. Cecal SCFA concentrations were increased compared to the control group, but no differences were observed between the different guar gum doses. Thus, no significant correlation was found between cecal SCFA concentrations and metabolic markers. In contrast, in vivo SCFA uptake fluxes by the host correlated linearly with metabolic markers. We argue that in vivo SCFA fluxes, and not concentrations, govern the protection from the metabolic syndrome by dietary fibers.

  19. The short-chain fatty acid uptake fluxes by mice on a guar gum supplemented diet associate with amelioration of major biomarkers of the metabolic syndrome.

    Directory of Open Access Journals (Sweden)

    Gijs den Besten

    Full Text Available Studies with dietary supplementation of various types of fibers have shown beneficial effects on symptoms of the metabolic syndrome. Short-chain fatty acids (SCFAs, the main products of intestinal bacterial fermentation of dietary fiber, have been suggested to play a key role. Whether the concentration of SCFAs or their metabolism drives these beneficial effects is not yet clear. In this study we investigated the SCFA concentrations and in vivo host uptake fluxes in the absence or presence of the dietary fiber guar gum. C57Bl/6J mice were fed a high-fat diet supplemented with 0%, 5%, 7.5% or 10% of the fiber guar gum. To determine the effect on SCFA metabolism, 13C-labeled acetate, propionate or butyrate were infused into the cecum of mice for 6 h and the isotopic enrichment of cecal SCFAs was measured. The in vivo production, uptake and bacterial interconversion of acetate, propionate and butyrate were calculated by combining the data from the three infusion experiments in a single steady-state isotope model. Guar gum treatment decreased markers of the metabolic syndrome (body weight, adipose weight, triglycerides, glucose and insulin levels and HOMA-IR in a dose-dependent manner. In addition, hepatic mRNA expression of genes involved in gluconeogenesis and fatty acid synthesis decreased dose-dependently by guar gum treatment. Cecal SCFA concentrations were increased compared to the control group, but no differences were observed between the different guar gum doses. Thus, no significant correlation was found between cecal SCFA concentrations and metabolic markers. In contrast, in vivo SCFA uptake fluxes by the host correlated linearly with metabolic markers. We argue that in vivo SCFA fluxes, and not concentrations, govern the protection from the metabolic syndrome by dietary fibers.

  20. n-3 Polyunsaturated Fatty Acids and their Role in Cancer Chemoprevention

    OpenAIRE

    Gu, Zhennan; Shan, Kai; Chen, Haiqin; Chen, Yong Q.

    2015-01-01

    Polyunsaturated fatty acids (PUFAs), including omega-3 (n-3) and omega-6 (n-6) PUFAs, are essential for human health. Recent research shows n-3 PUFAs and their mediators can inhibit inflammation, angiogenesis and cancer via multiple mechanisms, including reduced release of n-6 fatty acid arachidonic acid from cell membranes, inhibition of enzymatic activities, and direct competition with arachidonic acid for enzymatic conversions. In this review, we discuss inflammation-related cancer, anti-i...

  1. Influence of sodium chloride and weak organic acids (flux residues) on electrochemical migration of tin on surface mount chip components

    DEFF Research Database (Denmark)

    Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

    2013-01-01

    The electrolytic properties of sodium chloride and no-clean solder flux residue, and their effects on electrochemical migration and dendrite growth on surface mount chip capacitors were investigated. The leakage current dependency on concentration of contaminants was measured by a solution...... showed a difference which is caused by polarization effects, and demonstrated existing issues when indexing contamination levels on printed circuit board assemblies using a standardised solvent extract method. The experimental results showed that dendrite growth was dependent on the type and amount...

  2. 13C based proteinogenic amino acid (PAA and metabolic flux ratio analysis of Lactococcus lactis reveals changes in pentose phosphate (PP pathway in response to agitation and temperature related stresses

    Directory of Open Access Journals (Sweden)

    Kamalrul Azlan Azizan

    2017-07-01

    Full Text Available Lactococcus lactis subsp. cremoris MG1363 is an important starter culture for dairy fermentation. During industrial fermentations, L. lactis is constantly exposed to stresses that affect the growth and performance of the bacterium. Although the response of L. lactis to several stresses has been described, the adaptation mechanisms at the level of in vivo fluxes have seldom been described. To gain insights into cellular metabolism, 13C metabolic flux analysis and gas chromatography mass spectrometry (GC-MS were used to measure the flux ratios of active pathways in the central metabolism of L. lactis when subjected to three conditions varying in temperature (30°C, 37°C and agitation (with and without agitation at 150 rpm. Collectively, the concentrations of proteinogenic amino acids (PAAs and free fatty acids (FAAs were compared, and Pearson correlation analysis (r was calculated to measure the pairwise relationship between PAAs. Branched chain and aromatic amino acids, threonine, serine, lysine and histidine were correlated strongly, suggesting changes in flux regulation in glycolysis, the pentose phosphate (PP pathway, malic enzyme and anaplerotic reaction catalysed by pyruvate carboxylase (pycA. Flux ratio analysis revealed that glucose was mainly converted by glycolysis, highlighting the stability of L. lactis’ central carbon metabolism despite different conditions. Higher flux ratios through oxaloacetate (OAA from pyruvate (PYR reaction in all conditions suggested the activation of pyruvate carboxylate (pycA in L. lactis, in response to acid stress during exponential phase. Subsequently, more significant flux ratio differences were seen through the oxidative and non-oxidative pentose phosphate (PP pathways, malic enzyme, and serine and C1 metabolism, suggesting NADPH requirements in response to environmental stimuli. These reactions could play an important role in optimization strategies for metabolic engineering in L. lactis. Overall

  3. ω-Alkynyl lipid surrogates for polyunsaturated fatty acids: free radical and enzymatic oxidations.

    Science.gov (United States)

    Beavers, William N; Serwa, Remigiusz; Shimozu, Yuki; Tallman, Keri A; Vaught, Melissa; Dalvie, Esha D; Marnett, Lawrence J; Porter, Ned A

    2014-08-13

    Lipid and lipid metabolite profiling are important parameters in understanding the pathogenesis of many diseases. Alkynylated polyunsaturated fatty acids are potentially useful probes for tracking the fate of fatty acid metabolites. The nonenzymatic and enzymatic oxidations of ω-alkynyl linoleic acid and ω-alkynyl arachidonic acid were compared to that of linoleic and arachidonic acid. There was no detectable difference in the primary products of nonenzymatic oxidation, which comprised cis,trans-hydroxy fatty acids. Similar hydroxy fatty acid products were formed when ω-alkynyl linoleic acid and ω-alkynyl arachidonic acid were reacted with lipoxygenase enzymes that introduce oxygen at different positions in the carbon chains. The rates of oxidation of ω-alkynylated fatty acids were reduced compared to those of the natural fatty acids. Cyclooxygenase-1 and -2 did not oxidize alkynyl linoleic but efficiently oxidized alkynyl arachidonic acid. The products were identified as alkynyl 11-hydroxy-eicosatetraenoic acid, alkynyl 11-hydroxy-8,9-epoxy-eicosatrienoic acid, and alkynyl prostaglandins. This deviation from the metabolic profile of arachidonic acid may limit the utility of alkynyl arachidonic acid in the tracking of cyclooxygenase-based lipid oxidation. The formation of alkynyl 11-hydroxy-8,9-epoxy-eicosatrienoic acid compared to alkynyl prostaglandins suggests that the ω-alkyne group causes a conformational change in the fatty acid bound to the enzyme, which reduces the efficiency of cyclization of dioxalanyl intermediates to endoperoxide intermediates. Overall, ω-alkynyl linoleic acid and ω-alkynyl arachidonic acid appear to be metabolically competent surrogates for tracking the fate of polyunsaturated fatty acids when looking at models involving autoxidation and oxidation by lipoxygenases.

  4. Metabolic flux between unsaturated and saturated fatty acids is controlled by the FabA:FabB ratio in the fully reconstituted fatty acid biosynthetic pathway of Escherichia coli.

    Science.gov (United States)

    Xiao, Xirui; Yu, Xingye; Khosla, Chaitan

    2013-11-19

    The entire fatty acid biosynthetic pathway of Escherichia coli, starting from the acetyl-CoA carboxylase, has been reconstituted in vitro from 14 purified protein components. Radiotracer analysis verified stoichiometric conversion of acetyl-CoA and NAD(P)H to the free fatty acid product, allowing implementation of a facile spectrophotometric assay for kinetic analysis of this multienzyme system. At steady state, a maximal turnover rate of 0.5 s(-1) was achieved. Under optimal turnover conditions, the predominant products were C16 and C18 saturated as well as monounsaturated fatty acids. The reconstituted system allowed us to quantitatively interrogate the factors that influence metabolic flux toward unsaturated versus saturated fatty acids. In particular, the concentrations of the dehydratase FabA and the β-ketoacyl synthase FabB were found to be crucial for controlling this property. Via changes in these variables, the percentage of unsaturated fatty acid produced could be adjusted between 10 and 50% without significantly affecting the maximal turnover rate of the pathway. Our reconstituted system provides a powerful tool for understanding and engineering rate-limiting and regulatory steps in this complex and practically significant metabolic pathway.

  5. Humic acid acts as a natural antidote of graphene by regulating nanomaterial translocation and metabolic fluxes in vivo.

    Science.gov (United States)

    Hu, Xiangang; Mu, Li; Kang, Jia; Lu, Kaicheng; Zhou, Ruiren; Zhou, Qixing

    2014-06-17

    Graphene-related research has intensified rapidly in a wide range of disciplines, but few studies have examined ecosystem risks, particularly phytotoxicity. This study revealed that graphene significantly inhibits the number of wheat roots and the biosynthesis of chlorophyll, and altered the morphology of shoots. Humic acid (HA), a ubiquitous form of natural organic matter, significantly (P nanomaterial risks and can be used to control nanomaterial contamination.

  6. Regulation of adipose branched-chain amin acid catabolism enzyme expression and cross-adipose amino acid flux in human obesity

    Science.gov (United States)

    Elevated blood branched-chain amin acids (BCAA)are often assoicated with insulin resistance and type2 diabetes, which might result from a reduced cellular utilization and/or incomplete BCAA oxidation. White adipose tissue (WAT) has become appreciated as a potential player in whole body BCAA metaboli...

  7. Fibroblast Fatty-Acid Oxidation Flux Assays Stratify Risk in Newborns with Presumptive-Positive Results on Screening for Very-Long Chain Acyl-CoA Dehydrogenase Deficiency

    Directory of Open Access Journals (Sweden)

    Simon E. Olpin

    2017-02-01

    Full Text Available Very-long chain acyl-CoA dehydrogenase deficiency (VLCADD is a clinically heterogeneous disorder with three major phenotypes: severe neonatal/infantile, milder childhood and late onset myopathic. VLCADD is genetically heterogeneous with numerous pathogenic mutations and variants of uncertain significance. VLCADD is included in many newborn screening programs but these suffer from high false positive rates, primarily due to positive screens in heterozygotes. Separating these and newborns with two low-risk “mild” variants from clinically at risk patients can be problematic, as clinical and biochemical markers are often unreliable, particularly in stable neonates. We have measured fibroblast fatty acid oxidation flux using [9,10-H3]myristic acid and [9,10-H3]oleic acid from 69 clinically presenting VLCADD patients including myopathic and infantile phenotypes and 13 positive newborn screened patients. We also measured fibroblast VLCADD enzyme activity by UV-HPLC detection of product in a sub-set of patients and compared these results to oleate FAO-flux. Fibroblast enzyme assay by UV-HPLC detection failed to clearly discriminate between some clinically presenting VLCADD patient cell lines and cell lines from some simple heterozygotes. FAO-flux clearly discriminated between clinically presenting VLCADD patients and the false positive screened patients. FAO-flux at 37 °C provides information as to the likely clinical phenotype but FAO-flux at 41 °C is the best discriminator for identifying clinically at risk patients.

  8. Phloem sugar flux and jasmonic acid-responsive cell wall invertase control extrafloral nectar secretion in Ricinus communis.

    Science.gov (United States)

    Millán-Cañongo, Cynthia; Orona-Tamayo, Domancar; Heil, Martin

    2014-07-01

    Plants secrete extrafloral nectar (EFN) that attracts predators. The efficiency of the resulting anti-herbivore defense depends on the quantity and spatial distribution of EFN. Thus, according to the optimal defense hypothesis (ODH), plants should secrete EFN on the most valuable organs and when herbivore pressure is high. Ricinus communis plants secreted most EFN on the youngest (i.e., most valuable) leaves and after the simulation of herbivory via the application of jasmonic acid (JA). Here, we investigated the physiological mechanisms that might produce these seemingly adaptive spatiotemporal patterns. Cell wall invertase (CWIN; EC 3.2.1.26) was most active in the hours before peak EFN secretion, its decrease preceded the decrease in EFN secretion, and CWIN activity was inducible by JA. Thus, CWIN appears to be a central player in EFN secretion: its activation by JA is likely to cause the induction of EFN secretion after herbivory. Shading individual leaves decreased EFN secretion locally on these leaves with no effect on CWIN activity in the nectaries, which is likely to be because it decreased the content of sucrose, the substrate of CWIN, in the phloem. Our results demonstrate how the interplay of two physiological processes can cause ecologically relevant spatiotemporal patterns in a plant defense trait.

  9. Effects of forage intake level on nitrogen net flux by portal-drained viscera of mature sheep with abomasal infusion of an amino acid mixture.

    Science.gov (United States)

    EL-Sabagh, M; Sugino, T; Obitsu, T; Taniguchi, K

    2013-10-01

    This study aimed to investigate the pattern of nitrogen (N) metabolites flux across the portal-drained viscera (PDV) of mature sheep over a wide range of forage intake, and to determine the effect of dry matter intake (DMI) on the PDV recovery of an abomasally infused amino acids (AA) mixture. Four Suffolk mature sheep (61.4 ± 3.6 kg BW) surgically fitted with abomasal cannulae and multi-catheters were fed four levels of DMI of lucerne hay cubes ranging from 0.4 to 1.6 fold the metabolizable energy requirements for maintenance. Each period lasted for 17 days: 7 days for diet adaptation, 5 days for measurement of N balance and N metabolites flux under basal pre-infusion conditions (basal phase) and 5 days for determining the recovery of the infused AA (584 mmol/day) across the PDV (infusion phase). Six sets of blood samples were collected on the last day of both basal and infusion phases. Increasing DMI increased portal release of AA and enhanced N retention. At 0.4 M and as a proportion of digested N, there was a marked drop in total AA-N release accompanied by greater ammonia-N release and urea-N uptake across the PDV. The incremental recovery ratio of infused AA across the PDV was altered with increasing DMI accounting for 0.88, 1.12, 1.23 and 1.31 at 0.4, 0.8, 1.2 and 1.6 M, respectively. In addition, across the individual AA, the net portal recovery ratio of infused methionine and valine increased linearly (P < 0.05) while that of phenylalanine, branched-chain AA and total essential AA tended to increase linearly (P < 0.10) with increasing DMI. These results indicated that DMI affects the net portal recovery of AA available in the small intestine of mature sheep.

  10. Studies on the fatty acids of the red alga Chondria armata (Kutz.) okamura

    Digital Repository Service at National Institute of Oceanography (India)

    Govenkar, M.B.; Wahidullah, S.

    of arachidonic acid in algae. Phytochemis- try 8: 190721915. Roessler, P. G. 1990. Environmental control of glycerolipid metabolism in microalgae; commercial implication and future research direction. J. Phycol. 26: 3932399. Rosell, K. G. and L. M. Srivastava...

  11. Methane Flux

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Methane (CH4) flux is the net rate of methane exchange between an ecosystem and the atmosphere. Data of this variable were generated by the USGS LandCarbon project...

  12. Arachidonate Metabolism in Breast Cancer Cultures: Identification of Antagonists/Agonist for Possible Intervention Strategies.

    Science.gov (United States)

    1995-10-01

    counter which we are now using is so powerful that we needed to take the time to compare many options and see what labor -saving techniques can be...fluorescence assay is still under evaluation. As mentioned in Methods, the Top Count scintillation counter is a significant labor -saving piece of...estrogen receptors, markers of Go, and responsiveness to hormones and other growth factors such as oxytocin and IGF-I. 2. Generation of arachidonate

  13. Effects of particle size and dry matter content of a total mixed ration on intraruminal equilibration and net portal flux of volatile fatty acids in lactating dairy cows

    DEFF Research Database (Denmark)

    Storm, Adam Christian; Kristensen, Niels Bastian

    2010-01-01

    Effects of physical changes in consistency of ruminal contents on intraruminal equilibration and net portal fluxes of volatile fatty acids (VFA) in dairy cows were studied. Four Danish Holstein cows (121 ± 17 d in milk, 591 ± 24 kg of body weight, mean ± SD) surgically fitted with a ruminal cannula......H or milk fat percentage. Cows maintained average ventral ruminal pH of 6.65 ± 0.02, medial ruminal pH of 5.95 ± 0.04, and milk fat of 4.42 ± 0.12% with chewing time of 28.0 ± 2.1 min/kg of DM when fed short particles. The medial ruminal pool of wet particulate matter was decreased by 10.53 ± 2.29 kg...... particles. The estimated ruminal fluid flow and therefore intraruminal VFA transport between medial and ventral phase was not affected by the FPS. In conclusion, the ruminal mat pool of VFA was proportional to the size of the mat and the only detected effects of decreasing FPS were decreasing the mat size...

  14. Small amount of water induced preparation of several morphologies for InBO3:Eu3+ phosphor via a facile boric acid flux method and their luminescent properties

    Science.gov (United States)

    Ding, Wen; Liang, Pan; Liu, Zhi-Hong

    2017-05-01

    Four kinds of morphologies for InBO3:Eu3+ phosphor have been prepared via a facile boric acid flux method only by adjusting the small amount of added water. The prepared samples have been characterized by XRD, FT-IR, and SEM. It was found that the size and morphology of the samples could be effectively controlled by adjusting reaction temperature, reaction time, especially the small amount of added water, which plays an extremely critical role in the controlling morphology. The possible growth mechanisms for microsphere and flower-like morphologies were further discussed on the basis of time-dependent experiments. Furthermore, the luminescence properties of prepared InBO3:Eu3+ samples have been investigated by photoluminescence (PL) spectra. The results show that the InBO3:Eu3+ phosphors show strong orange emissions under ultraviolet excitation at 237 nm. The monodisperse microsphere sample possesses the highest PL intensity among above four morphologies, which can be used as a potential orange luminescent material.

  15. Specific high-affinity binding of fatty acids to epidermal cytosolic proteins

    Energy Technology Data Exchange (ETDEWEB)

    Raza, H.; Chung, W.L.; Mukhtar, H. (Department of Dermatology, University Hospitals of Cleveland, Case Western Reserve University, OH (USA))

    1991-08-01

    Cytosol from rat, mouse, and human skin or rat epidermis was incubated with (3H)arachidonic acid, (14C)retinoic acid, (14C)oleic acid, (3H)leukotriene A4, (3H)prostaglandin E2 (PGE2) or (3H) 15-hydroxyeicosatetraenoic acid (15-HETE), and protein-bound ligands were separated using Lipidex-1000 at 4C to assess the binding specificity. The binding of oleic acid and arachidonic acid with rat epidermal cytosol was rapid, saturable, and reversible. Binding of oleic acid was competed out with the simultaneous addition of other ligands and found to be in the following order: arachidonic acid greater than oleic acid greater than linoleic acid greater than lauric acid greater than leukotriene A4 greater than 15-HETE = PGE1 greater than PGE2 = PGF2. Scatchard analysis of the binding with arachidonic acid, oleic acid, and retinoic acid revealed high-affinity binding sites with the dissociation constant in the nM range. SDS-PAGE analysis of the oleic acid-bound epidermal cytosolic protein(s) revealed maximum binding at the 14.5 kDa region. The presence of the fatty acid-binding protein in epidermal cytosol and its binding to fatty acids and retinoic acid may be of significance both in the trafficking and the metabolism of fatty acids and retinoids across the skin.

  16. Effects of Fish Oil Diet and Age on the Fatty Acid Composition and the Endogenous Lipase Activity in Mouse Brain.

    Science.gov (United States)

    Suzuki, H; Jin, Z; Wada, O

    2000-01-01

    The influences of a fish oil diet and aging on the fatty acid composition in mouse brain, and the release of polyunsaturated fatty acids from brain membranes by endogenous lipase were studied. The changes in brain fatty acid composition with aging were determined in 5-weeks, 5-months and 19-months old mice fed on a commercial chow. Mice of different ages were also fed a fish oil or lard diet for 30 days, and the influence of the diets on brain fatty acid composition and endogenous lipase activity was analyzed. In aged mice fed on a commercial chow brain arachidonic acid and docosahexaenoic acid (%) decreased significantly, whereas blood arachidonic acid (%) increased and docosahexaenoic acid (%) did not change. The percentages of brain docosahexaenoic acid were significantly higher but those of arachidonic acid were lower in the fish oil diet group than in the lard diet group. However, there were no significant differences in the endogenous lipase activity between the different age or dietary groups. The release of arachidonic acid showed a tendency to decrease and docosahexaenoic acid to increase in mice fed on the fish oil diet. These results suggest that dietary lipids affect the percentages of arachidonic and docosahexaenoic acids which are released by the endogenous lipase in brain although the decreases in brain polyunsaturated fatty acid content with aging are not due to the enzyme activation, and dietary lipids do not influence the enzyme activity.

  17. Synthesis of long-chain polyunsaturated fatty acids in preterm newborns fed formula with long-chain polyunsaturated fatty acids

    NARCIS (Netherlands)

    Carnielli, Virgilio P.; Simonato, Manuela; Verlato, Giovanna; Luijendijk, Ingrid; De Curtis, Mario; Sauer, Pieter J. J.; Cogo, Paola E.

    2007-01-01

    Background: Docosahexaenoic acid (DHA) and arachidonic acid (AA) are long-chain polyunsaturated fatty acids (LCPs) that play pivotal roles in growth and neurodevelopment. Objective: We aimed to quantify the synthesis of LCPs in preterm infants fed infant formula containing LCPs. Design: Twenty-two p

  18. Oxidative modulation of transient potassium current by arachidonic acid in brain central neurons

    OpenAIRE

    Angelova, Plamena

    2007-01-01

    Der neuronale Zelluntergang bei einer Vielzahl von Krankheiten des ZNS, wie z.B. Morbus Alzheimer (AD) und Temporallappenepilepsie (TLE), wird mit oxidativem Stress sowie Fehlfunktionen von Kaliumkanälen in Verbindung gebracht. In dieser Studie soll die selektive neuronale Sensitivität auf oxidativen Stress durch die Messung der oxidativen Modulation von Kaliumströmen untersucht werden. Dabei werden sternförmige Neuronen der zweiten Schicht des entorhinalen Kortex (EC) (bei AD bereits früh ge...

  19. Arachidonic and oleic acid exert distinct effects on the DNA methylome

    DEFF Research Database (Denmark)

    Silva-Martínez, Guillermo A; Rodríguez-Ríos, Dalia; Alvarado-Caudillo, Yolanda

    2016-01-01

    embryonic fibroblasts. Comparisons with publicly available data were conducted by standard bioinformatics. AA and OA elicited a complex response marked by a general DNA hypermethylation and hypomethylation in the 1-200 μM range, respectively, with a maximal differential response at the 100 μM dose...

  20. Effect of steroid hormones on arachidonic acid metabolites of endothelial cells.

    Science.gov (United States)

    Witter, F R; DiBlasi, M C

    1984-05-01

    The effect of estrogen, progesterone, testosterone, and hydrocortisone on prostacyclin, thromboxane, prostaglandin E, and prostaglandin F from cultured endothelial cells was investigated. No effect was found on prostacyclin, prostaglandin E, and prostaglandin F. Estrogen increased the release of thromboxane. The significance of this finding with regard to venous thrombolic events associated with estrogen use is discussed.

  1. Glutamate signalling and secretory phospholipase A2 modulate the release of arachidonic acid from neuronal membranes

    DEFF Research Database (Denmark)

    Rodriguez De Turco, Elena B; Jackson, Fannie R; DeCoster, Mark A

    2002-01-01

    and secretory PLA(2) (sPLA(2)) from bee venom (bv sPLA(2)) and Taipan snake venom (OS2) elicit synergy in inducing neuronal cell death. Low concentrations of sPLA(2) are selective ligands of cell-surface sPLA(2) receptors. We investigated which neuronal arachidonoyl phospholipids are targeted by glutamate...

  2. Arachidonic acid metabolism and inhibition of cyclooxygenase in platelets from asthmatic subjects with aspirin intolerance.

    Science.gov (United States)

    Bonne, C; Moneret-Vautrin, D A; Wayoff, M; Descharmes, A; Gazel, P; Legrand, A; Kalt, C

    1985-02-01

    Exaggerated inhibition of cyclooxygenase has been proposed as a mechanism of drug-induced bronchospasm in aspirin-intolerant patients. This study, using platelets, shows that inhibition of prostaglandin biosynthesis by aspirin is unmodified in patients when compared with healthy subjects. The ratio of cyclooxygenase:lipoxygenase products is similar in platelets from patients and control subjects. We conclude that the cyclooxygenase alteration observed in cells from the respiratory tract is not generalised to other cells such as platelets. We also propose that the major abnormality in NSAID-intolerant patients would affect receptivity to lipoxygenase products more than their biosynthesis.

  3. Effects of some iridoids from plant origin on arachidonic acid metabolism in cellular systems.

    Science.gov (United States)

    Bermejo Benito, P; Díaz Lanza, A M; Silván Sen, A M; De Santos Galindez, J; Fernandez Matellano, L; Sanz Gómez, A; Abad Martínez, M J

    2000-05-01

    Seven iridoid glycosides isolated from different extracts of Scrophularia scorodonia L., namely bartsioside, aucubin, harpagide, harpagoside, 8-acetylharpagide, scorodioside and scropolioside B, had been evaluated for their in vitro anti-inflammatory activity in cellular systems generating COX and LOX metabolites. Structure-activity relationships obtained from in vitro screening results were discussed. Most compounds assayed did not exhibit any significant effect on PGE2- and LTC4-release from calcium ionophore-stimulated mouse peritoneal macrophages. In the LTC4-assay, only aucubin showed a significant effect, with an IC50 value of 72 microM. Harpagoside and harpagide also inhibited release of LTC4, but neither effect reached statistical significance. The release of PGE2 by mouse peritoneal macrophages stimulated with calcium ionophore was inhibited by harpagoside and 8-acetylharpagide, but this effect is not statistically significant. However, most iridoids assayed showed a significant effect on TXB2-release from calcium ionophorestimulated human platelets, with inhibition percentages slightly lower than the reference drug ibuprofen. Only harpagide, scorodioside and scropolioside B had no significant effect on TXB2-release. Our results indicate that selective inhibition of the TX-synthase enzyme may be the primary target of action of most of these iridoids, and one of the mechanisms through which they exert their anti-inflammatory effects.

  4. Influence of mineral dusts on metabolism of arachidonic acid by alveolar macrophage

    Energy Technology Data Exchange (ETDEWEB)

    Demers, L.M.; Kuhn, D.C. [Pennsylvania State University, Hershey, PA (United States). Dept. of Pathology

    1994-12-01

    The alveolar macrophage (AM) responds to stimuli such as coal mine dust by releasing inflammatory mediators such as cytokines, growth factors, reactive oxygen species, and eicosanoids. In this report, the authors examined the effects of an antioxidant, vitamin E, on dust-induced synthesis of PGE(2) and TXB(2) in vitro and in vivo by AM obtained by bronchoalveolar lavage from rats. They also looked at the effects of the surface of silica particles on AM eicosanoid biosynthesis under conditions of calcination, a process that removes exposed hydroxyl groups from the surface of silica particles, thus reducing the likelihood of soluble hydroxyl radical formation. Treatment of AM with vitamin E in vivo and in vitro reduced the augmentation in eicosanoid production usually observed when AM are exposed to mine dusts. These results suggest that vitamin E may effectively reduce the inflammatory and fibrotic response produced by inhalation of mineral dust through an antioxidant mechanism. Silica that has been chemically altered by calcination was unable to activate AM eicosanoid production in vitro when compared to untreated, freshly fractured silica. These findings suggest that the mechanism by which dust particles can activate AM eicosanoid release may involve interaction of surface and/or soluble factors with the cell membrane. Taken together, these studies point to the involvement of Am eicosanoid production as part of the proinflammatory response of this cell to occupational inhalation of mineral dust.

  5. Ozone effects on mechanics and arachidonic acid metabolite concentrations in isolated rat lungs

    Energy Technology Data Exchange (ETDEWEB)

    Joad, J.P.; McDonald, R.J.; Giri, S.N.; Bric, J.M. (Univ. of California, Davis, CA (United States))

    1994-08-01

    In whole animals, ozone acutely impairs pulmonary function, an effect which may be mediated by eicosanoids. This study determined if the lung itself, separated from blood components and the CNS, responds to ozone with increased eicosanoid production and decreased function. Wistar rat lungs were placed in a negatively ventilated, buffer-perfused, isolated system, where they were exposed to filtered air or 1 ppm ozone for 3 hr. ozone increased lung resistance (P = 0.02) and decreased dynamic compliance (P = 0.003, multivariate ANOVA for repeated measures). Pulmonary artery pressure, lung weight/body weight, and cells in lung lavage (BALF) did not change. In the perfusate, ozone increased the concentration of 6-keto-PGF[sub 1[alpha

  6. Relationships between Arachidonic Acid, Uterine Activity and Metabolic Regulation of Placental Lactogen Secretion.

    Science.gov (United States)

    1982-08-01

    conclusions can be made. Io I I 1~ .. MATERIALS AND METHODS 1. Fasting Study. Pregnant and non-pregnant Dorset ewes weighing 50 to 55 kg were selected from...the uterus. Amniotic catheters and flow probe cables were exteriorized from the abdominal cavity through the maternal flank via a metal trocar and...cannula. Vascular catheters and EMG wires were passed tn the opposite direction using a second trocar and 4I cannula. I. ,° * -- - - -31- The fetal head

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

    Science.gov (United States)

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

    2008-10-08

    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.

  8. Effect of amino acid supplementation on titer and glycosylation distribution in hybridoma cell cultures-Systems biology-based interpretation using genome-scale metabolic flux balance model and multivariate data analysis.

    Science.gov (United States)

    Reimonn, Thomas M; Park, Seo-Young; Agarabi, Cyrus D; Brorson, Kurt A; Yoon, Seongkyu

    2016-09-01

    Genome-scale flux balance analysis (FBA) is a powerful systems biology tool to characterize intracellular reaction fluxes during cell cultures. FBA estimates intracellular reaction rates by optimizing an objective function, subject to the constraints of a metabolic model and media uptake/excretion rates. A dynamic extension to FBA, dynamic flux balance analysis (DFBA), can calculate intracellular reaction fluxes as they change during cell cultures. In a previous study by Read et al. (2013), a series of informed amino acid supplementation experiments were performed on twelve parallel murine hybridoma cell cultures, and this data was leveraged for further analysis (Read et al., Biotechnol Prog. 2013;29:745-753). In order to understand the effects of media changes on the model murine hybridoma cell line, a systems biology approach is applied in the current study. Dynamic flux balance analysis was performed using a genome-scale mouse metabolic model, and multivariate data analysis was used for interpretation. The calculated reaction fluxes were examined using partial least squares and partial least squares discriminant analysis. The results indicate media supplementation increases product yield because it raises nutrient levels extending the growth phase, and the increased cell density allows for greater culture performance. At the same time, the directed supplementation does not change the overall metabolism of the cells. This supports the conclusion that product quality, as measured by glycoform assays, remains unchanged because the metabolism remains in a similar state. Additionally, the DFBA shows that metabolic state varies more at the beginning of the culture but less by the middle of the growth phase, possibly due to stress on the cells during inoculation. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1163-1173, 2016.

  9. GC-MS/MS survey of collision-induced dissociation of tert-butyldimethylsilyl-derivatized amino acids and its application to (13)C-metabolic flux analysis of Escherichia coli central metabolism.

    Science.gov (United States)

    Okahashi, Nobuyuki; Kawana, Shuichi; Iida, Junko; Shimizu, Hiroshi; Matsuda, Fumio

    2016-09-01

    Stable isotope labeling experiments using mass spectrometry have been employed to investigate carbon flow levels (metabolic flux) in mammalian, plant, and microbial cells. To achieve a more precise (13)C-metabolic flux analysis ((13)C-MFA), novel fragmentations of tert-butyldimethylsilyl (TBDMS)-amino acids were investigated by gas chromatography-tandem mass spectrometry (GC-MS/MS). The product ion scan analyses of 15 TBDMS-amino acids revealed 24 novel fragment ions. The amino acid-derived carbons included in the five fragment ions were identified by the analyses of (13)C-labeled authentic standards. The identification of the fragment ion at m/z 170 indicated that the isotopic abundance of S-methyl carbon in methionine could be determined from the cleavage of C5 in the precursor of [M-159](+) (m/z 218). It was also confirmed that the precision of (13)C-MFA in Escherichia coli central carbon metabolism could be improved by introducing (13)C-labeling data derived from novel fragmentations. Graphical Abstract Novel collision-induced dissociation fragmentations of tert-butyldimethylsilyl amino acids were investigated and identified by GC-MS/MS.

  10. Critical flux determination by flux-stepping

    DEFF Research Database (Denmark)

    Beier, Søren; Jonsson, Gunnar Eigil

    2010-01-01

    In membrane filtration related scientific literature, often step-by-step determined critical fluxes are reported. Using a dynamic microfiltration device, it is shown that critical fluxes determined from two different flux-stepping methods are dependent upon operational parameters such as step......, such values are more or less useless in itself as critical flux predictors, and constant flux verification experiments have to be conducted to check if the determined critical fluxes call predict sustainable flux regimes. However, it is shown that using the step-by-step predicted critical fluxes as start...

  11. EETs mediate cardioprotection of salvianolic acids through MAPK signaling pathway

    OpenAIRE

    Shoubao Wang; Weiku Zhang; Xiaobin Pang; Li Li; Guorong He; Xiuying Yang; Lianhua Fang; Juntian Zhang; Guanhua Du

    2013-01-01

    Salvianolic acids, including salvianolic acid A (SAA) and salvianolic acid B (SAB), are the main water-soluble bioactive compounds isolated from the Chinese medicinal herb Danshen and have been shown to exert in vitro and in vivo cardiovascular protection. Recent studies suggest that epoxyeicosatrienoic acids (EETs), the primary cytochrome P450 2J (CYP2J) epoxygenase metabolites of arachidonic acid, are involved in the progression of ischemic injury in diverse organs. Here, we investigated th...

  12. Effect of resistant starch on net portal-drained viscera flux of glucose, volatile fatty acids, urea, and ammonia in growing pigs

    NARCIS (Netherlands)

    Meulen, van der J.; Bakker, G.C.M.; Bakker, J.G.M.; Visser, de H.; Jongbloed, A.W.; Everts, H.

    1997-01-01

    Net portal-drained viscera (PDV) flux of glucose, VFA, ammonia, and urea was determined in pigs fed diets with or without resistant starch. Diets consisted of 65% cornstarch (diet CS), 32.5% cornstarch and 32.5% raw potato starch (diet CPS), or 65% raw potato starch (diet PS); the remaining 35% supp

  13. Metabolic flux analysis of recombinant Pichia pastoris growing on different glycerol/methanol mixtures by iterative fitting of NMR-derived (13)C-labelling data from proteinogenic amino acids.

    Science.gov (United States)

    Jordà, Joel; de Jesus, Sérgio S; Peltier, Solenne; Ferrer, Pau; Albiol, Joan

    2014-01-25

    The yeast Pichia pastoris has emerged as one of the most promising yeast cell factories for the production of heterologous proteins. The readily available genetic tools and the ease of high-cell density cultivations using methanol or glycerol/methanol mixtures are among the key factors for this development. Previous studies have shown that the use of mixed feeds of glycerol and methanol seem to alleviate the metabolic burden derived from protein production, allowing for higher specific and volumetric process productivities. However, initial studies of glycerol/methanol co-metabolism in P. pastoris by classical metabolic flux analyses using (13)C-derived Metabolic Flux Ratio (METAFoR) constraints were hampered by the reduced labelling information obtained when using C3:C1 substrate mixtures in relation to the conventional C6 substrate, that is, glucose. In this study, carbon flux distributions through the central metabolic pathways in glycerol/methanol co-assimilation conditions have been further characterised using biosynthetically directed fractional (13)C labelling. In particular, metabolic flux distributions were obtained under 3 different glycerol/methanol ratios and growth rates by iterative fitting of NMR-derived (13)C-labelling data from proteinogenic amino acids using the software tool (13)CFlux2. Specifically, cells were grown aerobically in chemostat cultures fed with 80:20, 60:40 and 40:60 (w:w) glycerol/methanol mixtures at two dilutions rates (0.05 hour(-1) and 0.16 hour(-1)), allowing to obtain additional data (biomass composition and extracellular fluxes) to complement pre-existing datasets. The performed (13)C-MFA reveals a significant redistribution of carbon fluxes in the central carbon metabolism as a result of the shift in the dilution rate, while the ratio of carbon sources has a lower impact on carbon flux distribution in cells growing at the same dilution rate. At low growth rate, the percentage of methanol directly dissimilated to CO2 ranges

  14. Arginine-vasopressin stimulates the formation of phosphatidic acid in rat Leydig cells

    DEFF Research Database (Denmark)

    Nielsen, J.R.; Hansen, Harald S.; Jensen, B.

    1987-01-01

    Arginine-vasopressin (AVP) stimulated the formation of labelled phosphatidic acid (PA) in [C]arachidonic acid-prelabelled rat Leydig cells. After addition of 10 M AVP [C]arachidonoylphosphatidic acid reached a maximum within 2 min. The increase was dose-dependent (10-10 M). No change in labelling...

  15. Modification of essential fatty acid composition in broodstock of cultured European eel Anguilla anguilla L

    DEFF Research Database (Denmark)

    Støttrup, Josianne; Jacobsen, Charlotte; Tomkiewicz, Jonna

    2013-01-01

    Farmed eels had lower levels of arachidonic acid (20:4 n-6) (ARA) and higher ratios of eicosapentaenoic acid (20:5 n-3) (EPA):ARA compared to wild European eels collected from the Baltic Sea and southern Norwegian coast. Eels fed a formulated feed (JD) with a distribution of essential fatty acids...

  16. Gestational age in relation to marine n-3 fatty acids in maternal erythrocytes

    DEFF Research Database (Denmark)

    Olsen, S.F.; Hansen, Harald S.; Sommer, S.;

    1991-01-01

    Gestation is longer in Faroese than Danish women, possibly because of the high intake of marine long-chain n-3 fatty acids that down regulates formation of prostaglandins from arachidonic acid. Polyunsaturated fatty acids were quantified in erythrocytes obtained within 2 days of delivery from...

  17. Changes in plasma and erythrocyte omega-6 and omega-3 fatty acids in response to intravenous supply of omega-3 fatty acids in patients with hepatic colorectal metastases

    OpenAIRE

    Al-Taan, Omer; Stephenson, James A.; Spencer, Laura; Pollard, Cristina; West, Annette L; Philip C. Calder; Metcalfe, Matthew; Dennison, Ashley R.

    2013-01-01

    Background Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are functionally the most important omega-3 polyunsaturated fatty acids (PUFAs). Oral supply of these fatty acids increases their levels in plasma and cell membranes, often at the expense of the omega-6 PUFAs arachidonic acid (ARA) and linoleic acid. This results in an altered pattern of lipid mediator production to one which is less pro-inflammatory. We investigated whether short term intravenous supply of omega-3 PUFAs co...

  18. Essential fatty acid requirements of cats: pathology of essential fatty acid deficiency.

    Science.gov (United States)

    MacDonald, M L; Anderson, B C; Rogers, Q R; Buffington, C A; Morris, J G

    1984-07-01

    The pathologic changes of essential fatty acid (EFA) deficiency were studied in specific-pathogen-free, domestic shorthair cats which were fed purified diets for 1.5 to 2.5 years. Cats fed an EFA-deficient diet exhibited signs of deficiency: severe fatty degeneration of the liver, excessive fat in the kidneys, dystrophic mineralization of the adrenal glands, degeneration of the testes, and hyperkeratosis of the skin. Minor clinical pathologic changes were consistent with liver damage. Fatty acid analyses of plasma lipids revealed low concentrations of linoleate and other n6-fatty acids, and high concentrations of n7- and n9-fatty acids, consistent with EFA deficiency. These signs of deficiency were prevented by including safflower seed oil in the diet at a concentration to supply linoleate at 6.7% of dietary energy. Therefore, linoleate is an EFA for the cat, despite negligible conversion of linoleate to arachidonate in cat liver. However, in cats fed a diet containing linoleate, but lacking arachidonate, there was mild mineralization of the kidneys, and the neutral fat content of the liver was slightly higher than that of cats fed a diet containing arachidonate and other long-chain polyunsaturated fatty acids. Also, 2 of the 19 cats fed arachidonate-deficient diets developed unusual inflammatory skin lesions. In cats fed a diet containing hydrogenated coconut oil, safflower seed oil, and chicken fat, fatty livers developed despite the presence of high levels of linoleate. The fatty livers appeared to result from a specific deleterious effect of the medium-chain triglycerides in hydrogenated coconut oil. Most of the organ pathologic changes of EFA deficiency in the cat can be prevented by feeding dietary linoleate. Linoleate meets the EFA requirement for functions which depend on proper membrane structure: growth, lipid transport, normal skin and coat condition, and maintenance of the epidermal permeability barrier. However, dietary arachidonate is required by the

  19. Stimulation of polyunsaturated fatty acid oxidation in myocytes by regulating its cellular uptake

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-aleem, S.; Frangakis, C. (Glaxo Inc., Research Triangle Park, NC (USA)); Badr, M. (Univ. of Missouri-Kansas City, MO (USA))

    1991-01-01

    In order to investigate the regulation of polyunsaturated fatty acid oxidation in the heart, the effect of the phosphodiesterase inhibitor enoximone on the oxidation of (1-{sup 14}C) arachidonic acid, and (1-{sup 14}C) arachidonyl-CoA, were studied in adult rat myocytes, and isolated rat heart mitochondria. Enoximone stimulated arachidonate oxidation by 94%, at a concentration of 0.25 mM. The apparent Vmax value of archidonate oxidation in the presence of enoximone was approximately 75% higher than the value observed with the control in isolated myocytes. Also, enoximone stimulated arachidonate uptake by 27% at a concentration of 0.25 mM. On the other hand, enoximone had no effect on the oxidation of (1-{sup 14}C) arachidonyl-CoA in isolated rat heart mitochondria. These results suggest that the oxidation of polyunsaturated fatty acids in myocytes is regulated by the rate of uptake of these acids across sarcolemmal membranes.

  20. Acid Resistant Lead Free Flux for Ceramic On-glaze Coblat Blue Pigments%陶瓷釉上钴蓝颜料用耐酸无铅熔剂的研究

    Institute of Scientific and Technical Information of China (English)

    余峰; 卢希龙; 陈婧; 冯枫; 曹春娥

    2012-01-01

    采用固相法合成了硅锌矿型钴蓝色料,然后选取耐酸性较强的无铅熔剂与色料按照一定比例混合,在一定温度下彩烤得到钴蓝颜料.通过单因素试验、正交试验对熔剂配方进行优化,制得呈色鲜艳、耐酸性良好的釉上钴蓝颜料.XRD分析结果表明:彩烤后颜料中存在(Co,Zn)2SiO4和ZrSiO4晶相.%Willemite type cobalt blue colorant was prepared by the solid state synthesis. Flux of high acid resistance and the as-prepared colorant were mixed in a proper proportion followed by decoration firing. Single factor experiments and orthogonal tests were carried out to optimize the composition of flux. On-glaze coblat blue pigments with rich-brilliant coloration and excellent acid resistance were successfully prepared. XRD results indicate that (Co,Zn)2SiO4 and ZrSiO4 crystals present in the pigments after decoration firing.

  1. Flux-P: Automating Metabolic Flux Analysis

    OpenAIRE

    Ebert, Birgitta E.; Anna-Lena Lamprecht; Bernhard Steffen; Blank, Lars M.

    2012-01-01

    Quantitative knowledge of intracellular fluxes in metabolic networks is invaluable for inferring metabolic system behavior and the design principles of biological systems. However, intracellular reaction rates can not often be calculated directly but have to be estimated; for instance, via 13C-based metabolic flux analysis, a model-based interpretation of stable carbon isotope patterns in intermediates of metabolism. Existing software such as FiatFlux, OpenFLUX or 13CFLUX supports experts in ...

  2. Influence d'une microsporidiose à Thelohania contejeani sur le métabolisme des acides gras totaux, musculaires, hépatopancréatiques et hémolymphatiques chez l'Écrevisse Austropotamobius pallipes le reboulet, 1858.

    Science.gov (United States)

    Kabre, G

    1988-03-01

    The fatty acids of muscular, hepatopancreatic, hemolymphatic of complete lipids of A. pallipes have a high degree of insaturation (40-50%). Palmitic, eicosapentenoïc, arachidonic, stearic, oleic acids are more than 90% of the acids. Into the parasited crayfishes, there is a decrease of the amount of the non-saturated acids and an increase of saturated acids rate.

  3. Inhibition of fatty acid synthesis in rat hepatocytes by exogenous polyunsaturated fatty acids is caused by lipid peroxidation

    DEFF Research Database (Denmark)

    Mikkelsen, L.; Hansen, Harald S.; Grunnet, N.

    1993-01-01

    by the peroxidized PUFA. Arachidonic acid and eicosapentaenoic acid showed a dose- and time-dependent cytotoxicity. Two other antioxidants: 50 µM a-tocopherol acid succinate and 1 µM N,N'-diphenyl-1,4-phenylenediamine, both proved more efficient than a-tocopherol phosphate. There was a significant correlation......Rat hepatocyte long-term cultures were utilized to investigate the impact of different polyunsaturated fatty acids (PUFA) on the insulin-induced de novo fatty acid synthesis in vitro. The addition of 0.5 mM albumin-complexed oleic, linoleic, columbinic, arachidonic, eicosapentaenoic...... or docosahexaenoic acid resulted in a marked suppression of fatty acid synthesis. By evaluation of cell viability (determined as the leakage of lactate dehydrogenase (LDH)) it turned our, that the antioxidant used (50 µM a-tocopherol phosphate) had a low antioxidant activity, resulting in cytotoxic effects...

  4. Mechanisms in bradykinin stimulated arachidonate release and synthesis of prostaglandin and platelet activating factor

    Directory of Open Access Journals (Sweden)

    D. Ricupero

    1992-01-01

    Full Text Available Regulatory mechanisms in bradykinin (BK activated release of arachidonate (ARA and synthesis of prostaglandin (PG and platelet activating factor (PAF were studied in bovine pulmonary artery endothelial cells (BPAEC. A role for GTP binding protein (G-protein in the binding of BK to the cells was determined. Guanosine 5-O- (thiotriphosphate, (GTPτS, lowered the binding affinity for BK and increased the Kd for the binding from 0.45 to 1.99 nM. The Bmax remained unaltered at 2.25 × 10-11 mole. Exposure of the cells to aluminium fluoride also reduced the affinity for BK. Bradykinin-induced release of ARA proved pertussis toxin (PTX sensitive, with a maximum sensitivity at 10 ug/ml PTX. GTPτS at 100 μM increased the release of arachidonate. The effect of GTPτS and BK was additive at suboptimal doses of BK up to 0.5 nM but never exceeded the levels of maximal BK stimulation at 50 nM. PTX also inhibited the release of ARA induced by the calcium ionophore, A23187. Phorbol 12-myristate 13-acetate or more commonly known as tetradecanoyl phorbol acetate (TPA itself had little effect on release by the intact cells. However, at 100 nM it augmented the BK activated release. This was downregulated by overnight exposure to TPA and correlated with down-regulation of protein kinase C (PKC activity. The down-regulation only affected the augmentation of ARA release by TPA but not the original BK activated release. TPA displayed a similar, but more potent amplification of PAF synthesis in response to both BK or the calcium ionophore A23187. These results taken together point to the participation of G-protein in the binding of BK to BPAEC and its activation of ARA release. Possibly two types of G-protein are involved, one associated with the receptor, the other activated by Ca2+ and perhaps associated with phospholipase A2 (PLA2. Our results further suggest that a separate route of activation, probably also PLA2 related, takes place through a PKC catalysed

  5. p38 mitogen-activated protein kinase interacts with vinculin at focal adhesions during fatty acid-stimulated cell adhesion.

    Science.gov (United States)

    George, Margaret D; Wine, Robert N; Lackford, Brad; Kissling, Grace E; Akiyama, Steven K; Olden, Kenneth; Roberts, John D

    2013-12-01

    Arachidonic acid stimulates cell adhesion by activating α2β1 integrins in a process that depends on protein kinases, including p38 mitogen activated protein kinase. Here, we describe the interaction of cytoskeletal components with key signaling molecules that contribute to the spreading of, and morphological changes in, arachidonic acid-treated MDA-MB-435 human breast carcinoma cells. Arachidonic acid-treated cells showed increased attachment and spreading on collagen type IV, as measured by electric cell-substrate impedance sensing. Fatty acid-treated cells displayed short cortical actin filaments associated with an increased number of β1 integrin-containing pseudopodia, whereas untreated cells displayed elongated stress fibers and fewer clusters of β1 integrins. Confocal microscopy of arachidonic acid-treated cells showed that vinculin and phospho-p38 both appeared enriched in pseudopodia and at the tips of actin filaments, and fluorescence ratio imaging indicated the increase was specific for the phospho-(active) form of p38. Immunoprecipitates of phospho-p38 from extracts of arachidonic acid-treated cells contained vinculin, and GST-vinculin fusion proteins carrying the central region of vinculin bound phospho-p38, whereas fusion proteins expressing the terminal portions of vinculin did not. These data suggest that phospho-p38 associates with particular domains on critical focal adhesion proteins that are involved in tumor cell adhesion and spreading, and that this association can be regulated by factors in the tumor microenvironment.

  6. Effect of Long-Chain Polyunsaturated Fatty Acid Supplementation on Neurodevelopmental Outcome in Full-Term Infants

    NARCIS (Netherlands)

    Hadders-Algra, Mijna

    2010-01-01

    It takes more than 20 years before the human brain obtains its complex, adult configuration. Most dramatic developmental changes occur prenatally and early postnatally. During development, long-chain polyunsaturated fatty acids (LCPUFA) such as doxosahexaenoic acid (DHA) and arachidonic acid (AA) ar

  7. FiatFlux--a software for metabolic flux analysis from 13C-glucose experiments.

    Science.gov (United States)

    Zamboni, Nicola; Fischer, Eliane; Sauer, Uwe

    2005-08-25

    Quantitative knowledge of intracellular fluxes is important for a comprehensive characterization of metabolic networks and their functional operation. In contrast to direct assessment of metabolite concentrations, in vivo metabolite fluxes must be inferred indirectly from measurable quantities in 13C experiments. The required experience, the complicated network models, large and heterogeneous data sets, and the time-consuming set-up of highly controlled experimental conditions largely restricted metabolic flux analysis to few expert groups. A conceptual simplification of flux analysis is the analytical determination of metabolic flux ratios exclusively from MS data, which can then be used in a second step to estimate absolute in vivo fluxes. Here we describe the user-friendly software package FiatFlux that supports flux analysis for non-expert users. In the first module, ratios of converging fluxes are automatically calculated from GC-MS-detected 13C-pattern in protein-bound amino acids. Predefined fragmentation patterns are automatically identified and appropriate statistical data treatment is based on the comparison of redundant information in the MS spectra. In the second module, absolute intracellular fluxes may be calculated by a 13C-constrained flux balancing procedure that combines experimentally determined fluxes in and out of the cell and the above flux ratios. The software is preconfigured to derive flux ratios and absolute in vivo fluxes from [1-13C] and [U-13C]glucose experiments and GC-MS analysis of amino acids for a variety of microorganisms. FiatFlux is an intuitive tool for quantitative investigations of intracellular metabolism by users that are not familiar with numerical methods or isotopic tracer experiments. The aim of this open source software is to enable non-specialists to adapt the software to their specific scientific interests, including other 13C-substrates, labeling mixtures, and organisms.

  8. FiatFlux – a software for metabolic flux analysis from 13C-glucose experiments

    Directory of Open Access Journals (Sweden)

    Fischer Eliane

    2005-08-01

    Full Text Available Abstract Background Quantitative knowledge of intracellular fluxes is important for a comprehensive characterization of metabolic networks and their functional operation. In contrast to direct assessment of metabolite concentrations, in vivo metabolite fluxes must be inferred indirectly from measurable quantities in 13C experiments. The required experience, the complicated network models, large and heterogeneous data sets, and the time-consuming set-up of highly controlled experimental conditions largely restricted metabolic flux analysis to few expert groups. A conceptual simplification of flux analysis is the analytical determination of metabolic flux ratios exclusively from MS data, which can then be used in a second step to estimate absolute in vivo fluxes. Results Here we describe the user-friendly software package FiatFlux that supports flux analysis for non-expert users. In the first module, ratios of converging fluxes are automatically calculated from GC-MS-detected 13C-pattern in protein-bound amino acids. Predefined fragmentation patterns are automatically identified and appropriate statistical data treatment is based on the comparison of redundant information in the MS spectra. In the second module, absolute intracellular fluxes may be calculated by a 13C-constrained flux balancing procedure that combines experimentally determined fluxes in and out of the cell and the above flux ratios. The software is preconfigured to derive flux ratios and absolute in vivo fluxes from [1-13C] and [U-13C]glucose experiments and GC-MS analysis of amino acids for a variety of microorganisms. Conclusion FiatFlux is an intuitive tool for quantitative investigations of intracellular metabolism by users that are not familiar with numerical methods or isotopic tracer experiments. The aim of this open source software is to enable non-specialists to adapt the software to their specific scientific interests, including other 13C-substrates, labeling mixtures

  9. Environment and phenology: CO2 net ecosystem exchange and CO2 flux partitioning at an acid and oligotrophic mire system in northern Sweden

    Science.gov (United States)

    Gažovič, Michal; Peichl, Matthias; Vermeij, Ilse; Limpens, Juul; Nilsson, Mats. B.

    2015-04-01

    Static chamber and environmental measurements in combination with vegetation indices (i.e. vascular green area (VGA) and the greenness chromatic color index (gcc) derived from digital camera images) were used to investigate effects of environment and phenology on the CO2 net ecosystem exchange (NEE) and CO2 flux partitioning at the Degerö Stormyr site in northern Sweden (64°11' 23.565" N, 19°33' 55.291 E) during two environmentally different years. Our measurement design included a control plot, a moss plot (where vascular plants were removed by clipping) and four heterotrophic respiration (RH) collars (where all green moss and vascular plant biomass were removed) to partition between soil heterotrophic and plant autotrophic (moss and vascular plants) respiration (RA), as well as between moss and vascular plant gross primary production (GPP). Environmental conditions, especially the shallow snow cover, peat soil frost and cold spring in 2014 caused delayed onset of spring green up, reduced soil respiration flux and reduced GPP of vascular plants. Soil temperature measured in 26 cm depth started to rise from spring temperatures of ~ 0.6 °C in 2013 and 0.15 °C in 2014 about 20 days earlier in 2013 compared to 2014. With earlier onset of the growing season and higher soil temperatures in 2013, heterotrophic soil respiration was higher in year 2013 than in year 2014. In 2013, RH dominated the total ecosystem respiration in all months but June and August. On contrary, autotrophic respiration dominated ecosystem respiration in all months of 2014. In both years, vascular plants and mosses were more or less equally contributing to autotrophic respiration. We measured higher GPP in year 2013 compared to year 2014. Also VGA and gcc were higher in spring and throughout the rest of 2013 compared to 2014. The onset of VGA was delayed by ~ 10 days in 2014. In general, total GPP was dominated by GPP of vascular plants in both years, although moss GPP had substantial

  10. The Short-Chain Fatty Acid Uptake Fluxes by Mice on a Guar Gum Supplemented Diet Associate with Amelioration of Major Biomarkers of the Metabolic Syndrome

    NARCIS (Netherlands)

    den Besten, Gijs; Havinga, Rick; Bleeker, Aycha; Rao, Shodhan; Gerding, Albert; van Eunen, Karen; Groen, Albert K.; Reijngoud, Dirk-Jan; Bakker, Barbara M.

    2014-01-01

    Studies with dietary supplementation of various types of fibers have shown beneficial effects on symptoms of the metabolic syndrome. Short-chain fatty acids (SCFAs), the main products of intestinal bacterial fermentation of dietary fiber, have been suggested to play a key role. Whether the concentra

  11. Interaction of fatty acid genotype and diet on changes in colonic fatty acids in a Mediterranean diet intervention study.

    Science.gov (United States)

    Porenta, Shannon R; Ko, Yi-An; Gruber, Stephen B; Mukherjee, Bhramar; Baylin, Ana; Ren, Jianwei; Djuric, Zora

    2013-11-01

    A Mediterranean diet increases intakes of n-3 and n-9 fatty acids and lowers intake of n-6 fatty acids. This can impact colon cancer risk as n-6 fatty acids are metabolized to proinflammatory eicosanoids. The purpose of this study was to evaluate interactions of polymorphisms in the fatty acid desaturase (FADS) genes, FADS1 and FADS2, and changes in diet on fatty acid concentrations in serum and colon. A total of 108 individuals at increased risk of colon cancer were randomized to either a Mediterranean or a Healthy Eating diet. Fatty acids were measured in both serum and colonic mucosa at baseline and after six months. Each individual was genotyped for four single-nucleotide polymorphisms in the FADS gene cluster. Linear regression was used to evaluate the effects of diet, genotype, and the diet by genotype interaction on fatty acid concentrations in serum and colon. Genetic variation in the FADS genes was strongly associated with baseline serum arachidonic acid (n-6) but serum eicosapentaenoic acid (n-3) and colonic fatty acid concentrations were not significantly associated with genotype. After intervention, there was a significant diet by genotype interaction for arachidonic acid concentrations in colon. Subjects who had all major alleles for FADS1/2 and were following a Mediterranean diet had 16% lower arachidonic acid concentrations in the colon after six months of intervention than subjects following the Healthy Eating diet. These results indicate that FADS genotype could modify the effects of changes in dietary fat intakes on arachidonic acid concentrations in the colon.

  12. Developmentally dependent and different roles of fatty acids OMEGA-6 and OMEGA-3

    DEFF Research Database (Denmark)

    Mourek, J; Mourek, J

    2011-01-01

    The developmentally-dependent differences in the biological significances and effects of PUFA-OMEGA-6 (namely of arachidonic acid) and PUFA-OMEGA-3 (namely of docosahexaenoic acid) are discussed. The clinical results as well as developmental experiences are indicating a hypothesis of the evolution...

  13. Long-chain polyunsaturated fatty acid status and early growth of low birth weight infants

    NARCIS (Netherlands)

    Woltil, HA; van Beusekom, CM; Schaafsma, A; Muskiet, FAJ; Okken, A

    1998-01-01

    We correlated arachidonic acid (AA) and docosahexaenoic acid (DHA) status with anthropometric measures and growth rates in a group of low birth weight infants (less than or equal to 2500 g; gestational ages 30-41 weeks; n = 143). AA and DHA status were measured in erythrocytes (RBC) and plasma chole

  14. Subchronic (13-week) oral toxicity study, preceded by an in utero exposure phase, with arachidonate-enriched triglyceride oil (SUNTGA40S) in rats.

    Science.gov (United States)

    Lina, B A R; Wolterbeek, A P M; Suwa, Y; Fujikawa, S; Ishikura, Y; Tsuda, S; Dohnalek, M

    2006-03-01

    Polyunsaturated fatty acids (PUFAs), such as arachidonic acid (ARA) and docosahexaenoic acid (DHA) are natural constituents found in human milk, fish oil or egg yolk. Until recently, infant formulas, though providing the essential fatty acid precursors for these PUFAs, did not contain preformed ARA or DHA. In this study the safety of SUNTGA40S as source of ARA, not only for use in infant formulas but also for nutritional products or food supplements, was evaluated in a subchronic study in Wistar rats, preceded by a 4-week pretreatment period of parental (F(0)) rats and exposure of the F(0) dams throughout mating, gestation and lactation. SUNTGA40S was administered at dietary levels of 0.5%, 1.5% and 5% (wt/wt) adjusted with corn oil to 5.76% added fat. An additional group received 3.65% (wt/wt) SUNTGA40S in conjunction with 2.11% (wt/wt) high DHA Tuna oil, providing an ARA:DHA ratio of 2.7:1. High-fat and low-fat controls received basal diet with or without 5.76% corn-oil supplement. The content, stability and homogeneous distribution of the test substances in the diet were confirmed under study conditions. The administration of SUNTGA40S, with or without DHA oil, did not affect health, growth, fertility or reproductive performance of the parental rats, nor pup characteristics (condition, weight gain, viability, number per litter or sex ratio). In the subchronic study with the offspring (F(1)) rats, no significant differences were found in condition, neurobehavioural observations, ophthalmoscopy, growth, urinalysis or macroscopic and microscopic findings between the test groups and the low-fat or the high-fat controls. In males of the 5% SUNTGA40S and the SUNTGA40S/DHA group, red blood cell counts, haemoglobin concentration and packed cell volume were lower and reticulocytes were slightly higher than in the high-fat and low-fat control groups. Cholesterol, triglycerides and phospholipids in plasma were lower than in the high-fat controls in both sexes in the 5

  15. Growth and development of term infants fed with milk with long-chain polyunsaturated fatty acid supplementation

    Institute of Scientific and Technical Information of China (English)

    BEN Xiao-ming 贲晓明; ZHOU Xiao-yu 周晓玉; ZHAO Wei-hua 赵卫华; YU Wen-liang 喻文亮; PAN Wei 潘伟; ZHANG Wei-li 张伟利; WU Sheng-mei 吴圣楣; Christien M. Van Beusekom; Anne Schaafsma

    2004-01-01

    @@ Presently, there is growing interest in long-chain polyunsaturated fatty acids (LCPUFAs), which are considered a major determinant of growth, visual and neural development, and long-term health.1 Two groups of LCPUFAs have received special interest: homologues of linoleic acid (LA) of the n-6 series, which are precursors of arachidonic acid (AA), and homologues of α-linolenic acid (ALA) of the n-3 series, which are precursors of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

  16. Inhibition of arachidonate 15-lipoxygenase prevents 4-hydroxynonenal-induced protein damage in male germ cells.

    Science.gov (United States)

    Bromfield, Elizabeth G; Mihalas, Bettina P; Dun, Matthew D; Aitken, R John; McLaughlin, Eileen A; Walters, Jessica L H; Nixon, Brett

    2017-03-01

    Lipid peroxidation products, such as 4-hydroxynonenal (4HNE), are causative agents responsible for extensive protein damage within the male and female germlines. Recently, we have demonstrated that 4HNE production can initiate the proteolytic degradation of the molecular chaperone Heat Shock Protein A2 (HSPA2) in male germ cells. These events may be partially responsible for HSPA2 deficiency in the spermatozoa of patients that repeatedly fail in vitro fertilization. Given this, mechanisms that limit the production of 4HNE will be highly advantageous for the preservation of male fertility. The propagation of 4HNE in somatic cells has been linked to the enzymatic actions of arachidonate 15-lipoxygenase (ALOX15), a member of the lipoxygenase family of proteins. In view of this association, this study sought to explore ALOX15 as a physiological target to manipulate the levels of 4HNE produced in the male germline. Herein, we have demonstrated that ALOX15 is markedly upregulated in response to oxidative stress in round spermatids and the GC-2 cell line. Pharmacological inhibition of ALOX15 in GC-2 cells resulted in a significant reduction in both mitochondrial and cytoplasmic reactive oxygen species, as well as a dramatic reduction in 4HNE. Importantly, the reduced bioavailability of this aldehyde appears to confer positive downstream effects to its target proteins such that HSPA2 could be protected from damage by 4HNE. Taken together, these results suggest that the actions of ALOX15 are intimately tied to the production of 4HNE. Thus, the ALOX15 protein may be a promising new target for the mitigation of germline oxidative stress. © The Authors 2017. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Flux-P: Automating Metabolic Flux Analysis

    Directory of Open Access Journals (Sweden)

    Birgitta E. Ebert

    2012-11-01

    Full Text Available Quantitative knowledge of intracellular fluxes in metabolic networks is invaluable for inferring metabolic system behavior and the design principles of biological systems. However, intracellular reaction rates can not often be calculated directly but have to be estimated; for instance, via 13C-based metabolic flux analysis, a model-based interpretation of stable carbon isotope patterns in intermediates of metabolism. Existing software such as FiatFlux, OpenFLUX or 13CFLUX supports experts in this complex analysis, but requires several steps that have to be carried out manually, hence restricting the use of this software for data interpretation to a rather small number of experiments. In this paper, we present Flux-P as an approach to automate and standardize 13C-based metabolic flux analysis, using the Bio-jETI workflow framework. Exemplarily based on the FiatFlux software, it demonstrates how services can be created that carry out the different analysis steps autonomously and how these can subsequently be assembled into software workflows that perform automated, high-throughput intracellular flux analysis of high quality and reproducibility. Besides significant acceleration and standardization of the data analysis, the agile workflow-based realization supports flexible changes of the analysis workflows on the user level, making it easy to perform custom analyses.

  18. The roles of long-chain polyunsaturated fatty acids in pregnancy, lactation and infancy: review of current knowledge and consensus recommendations

    DEFF Research Database (Denmark)

    Koletzko, Berthold; Lien, Eric; Agostoni, Carlo;

    2008-01-01

    This paper reviews current knowledge on the role of the long-chain polyunsaturated fatty acids (LC-PUFA), docosahexaenoic acid (DHA, C22:6n-3) and arachidonic acid (AA, 20:4n-6), in maternal and term infant nutrition as well as infant development. Consensus recommendations and practice guidelines...

  19. [Study of the fatty acid components of the triglyceride fraction of the blood in normal and thalassemic subjects, using gas chromatography].

    Science.gov (United States)

    Gilli, G; Moiraghi Ruggenini, A; Nani, E; Bottura, G; Mastretta, L

    1977-01-01

    Thin layer chromatography was used to separate the triglyceridic fraction of plasma lipides in normal (19) and thalassaemic (15) subjects. Gas chromatographic analysis of the fraction was then carried out and the fatty acids represented were identified qualitatively and quantitatively. Statistically significant variations, specifically increase in arachidonic acid and reduction in palmitic and linoleic acids, were observed in the thalassaemic patients.

  20. Dietary supplementation of essential fatty acids in larval pikeperch (Sander lucioperca); short and long term effects on stress tolerance and metabolic physiology

    DEFF Research Database (Denmark)

    Lund, Ivar; Skov, Peter Vilhelm; Hansen, Benni Winding

    2012-01-01

    The present study examined the effects of feeding pike perch larvae Artemia, enriched with either docosahexanoic acid (DHA), arachidonic acid (ARA), oleic acid (OA), olive oil (OO) or a commercial enrichment DHA Selco (DS) on tissue lipid deposition, stress tolerance, growth and development...

  1. Oxidizability of unsaturated fatty acids and of a non-phenolic lignin structure in the manganese peroxidase-dependent lipid peroxidation system

    Science.gov (United States)

    Alexander N. Kapich; Tatyana V. Korneichik; Annele Hatakka; Kenneth E. Hammel

    2010-01-01

    Unsaturated fatty acids have been proposed to mediate the oxidation of recalcitrant, non-phenolic lignin structures by fungal manganese peroxidases (MnP), but their precise role remains unknown. We investigated the oxidizability of three fatty acids with varying degrees of polyunsaturation (linoleic, linolenic, and arachidonic acids) by measuring conjugated dienes...

  2. Long-chain polyunsaturated fatty acids (LCPUFA) from genesis to senescence: the influence of LCPUFA on neural development, aging, and neurodegeneration.

    NARCIS (Netherlands)

    Janssen, C.I.F.; Kiliaan, A.J.

    2014-01-01

    Many clinical and animal studies demonstrate the importance of long-chain polyunsaturated fatty acids (LCPUFA) in neural development and neurodegeneration. This review will focus on involvement of LCPUFA from genesis to senescence. The LCPUFA docosahexaenoic acid and arachidonic acid are important

  3. Long-chain polyunsaturated fatty acids (LCPUFA) from genesis to senescence: the influence of LCPUFA on neural development, aging, and neurodegeneration.

    NARCIS (Netherlands)

    Janssen, C.I.F.; Kiliaan, A.J.

    2014-01-01

    Many clinical and animal studies demonstrate the importance of long-chain polyunsaturated fatty acids (LCPUFA) in neural development and neurodegeneration. This review will focus on involvement of LCPUFA from genesis to senescence. The LCPUFA docosahexaenoic acid and arachidonic acid are important c

  4. Manipulation of carbon flux into fatty acid biosynthesis pathway in Dunaliella salina using AccD and ME genes to enhance lipid content and to improve produced biodiesel quality

    Directory of Open Access Journals (Sweden)

    Ahmad Farhad Talebi

    2014-08-01

    Full Text Available Advanced generations of biofuels basically revolve around non-agricultural energy crops. Among those, microalgae owing to its unique characteristics i.e. natural tolerance to waste and saline water, sustainable biomass production and high lipid content (LC, is regarded by many as the ultimate choice for the production of various biofuels such as biodiesel. In the present study, manipulation of carbon flux into fatty acid biosynthesis pathway in Dunaliella salina was achieved using pGH plasmid harboring AccD and ME genes to enhance lipid content and to improve produced biodiesel quality. The stability of transformation was confirmed by PCR after several passages. Southern hybridization of AccD probe with genomic DNA revealed stable integration of the cassette in the specific positions in the chloroplast genome with no read through transcription by indigenous promoters. Comparison of the LC and fatty acid profile of the transformed algal cell line and the control revealed the over-expression of the ME/AccD genes in the transformants leading to 12% increase in total LC and significant improvements in biodiesel properties especially by increasing algal oil oxidation stability. The whole process successfully implemented herein for transforming algal cells by genes involved in lipid production pathway could be helpful for large scale biodiesel production from microalgae.

  5. Lack of excitatory amino acid-induced effects on calcium fluxes measured with sup 45 Ca sup 2+ in rat cerebral cortex synaptosomes

    Energy Technology Data Exchange (ETDEWEB)

    Simonato, M.; Jope, R.S.; Bianchi, C.; Beani, L. (Univ. of Ferrara (Italy))

    1989-07-01

    Ca{sup 2+} uptake was measured in purified rat cerebral cortex synaptosomes (P3 pellets) using {sup 45}Ca{sup 2+} as a tracer. Ca{sup 2+} influx increased in time, and with an increase in external K+ concentration and temperature. The net (external K+-induced, depolarization-dependent) uptake follows a two-component course. The exponential term, due to the opening of voltage-operated calcium channels (VOC), has a rate constant which increases with an increase in the depolarization level (1.04 versus 0.54 nmol/s/mg protein for 50 mM - versus 15 mM (K+)-dependent net influx). The linear term, due to the Na{sup +}/Ca{sup 2+} exchange system, has a similar rate constant at all depolarization levels (0.16 +/- 0.05 and 0.11 +/- 0.02 nmol/s/mg protein). Excitatory amino acids (glutamate, kainate and n-methyl-d-aspartate-NMDA-) were tested on this preparation at doses ranging between 5 x 10(-5) M and 5 x 10(-3) M and at multiple incubation times, under resting conditions and under two depolarizing conditions (partial depolarization: 15 mM external K{sup +} and maximal depolarization: 50 mM external K+). NMDA was also tested in the absence of Mg{sup 2+}. No effect was detectable under any of these experimental conditions. Hypotheses to interpret these data are discussed. Further studies on other preparations are needed in order to directly investigate the presynaptic effects of excitatory amino acids.

  6. Mechanistic Perspectives of Maslinic Acid in Targeting Inflammation

    Directory of Open Access Journals (Sweden)

    Wei Hsum Yap

    2015-01-01

    Full Text Available Chronic inflammation drives the development of various pathological diseases such as rheumatoid arthritis, atherosclerosis, multiple sclerosis, and cancer. The arachidonic acid pathway represents one of the major mechanisms for inflammation. Prostaglandins (PGs are lipid products generated from arachidonic acid by the action of cyclooxygenase (COX enzymes and their activity is blocked by nonsteroidal anti-inflammatory drugs (NSAIDS. The use of natural compounds in regulation of COX activity/prostaglandins production is receiving increasing attention. In Mediterranean diet, olive oil and table olives contain significant dietary sources of maslinic acid. Maslinic acid is arising as a safe and novel natural pentacyclic triterpene which has protective effects against chronic inflammatory diseases in various in vivo and in vitro experimental models. Understanding the anti-inflammatory mechanism of maslinic acid is crucial for its development as a potential dietary nutraceutical. This review focuses on the mechanistic action of maslinic acid in regulating the inflammation pathways through modulation of the arachidonic acid metabolism including the nuclear factor-kappa B (NF-κB/COX-2 expression, upstream protein kinase signaling, and phospholipase A2 enzyme activity. Further investigations may provide insight into the mechanism of maslinic acid in regulating the molecular targets and their associated pathways in response to specific inflammatory stimuli.

  7. Clustering of Emerging Flux

    Science.gov (United States)

    Ruzmaikin, A.

    1997-01-01

    Observations show that newly emerging flux tends to appear on the Solar surface at sites where there is flux already. This results in clustering of solar activity. Standard dynamo theories do not predict this effect.

  8. Different roles for non-receptor tyrosine kinases in arachidonate release induced by zymosan and Staphylococcus aureus in macrophages

    Directory of Open Access Journals (Sweden)

    Sundler Roger

    2006-05-01

    Full Text Available Abstract Background Yeast and bacteria elicit arachidonate release in macrophages, leading to the formation of leukotrienes and prostaglandins, important mediators of inflammation. Receptors recognising various microbes have been identified, but the signalling pathways are not entirely understood. Cytosolic phospholipase A2 is a major down-stream target and this enzyme is regulated by both phosphorylation and an increase in intracellular Ca2+. Potential signal components are MAP kinases, phosphatidylinositol 3-kinase and phospholipase Cγ2. The latter can undergo tyrosine phosphorylation, and Src family kinases might carry out this phosphorylation. Btk, a Tec family kinase, could also be important. Our aim was to further elucidate the role of Src family kinases and Btk. Methods Arachidonate release from murine peritoneal macrophages was measured by prior radiolabeling. Furthermore, immunoprecipitation and Western blotting were used to monitor changes in activity/phosphorylation of intermediate signal components. To determine the role of Src family kinases two different inhibitors with broad specificity (PP2 and the Src kinase inhibitor 1, SKI-1 were used as well as the Btk inhibitor LFM-A13. Results Arachidonate release initiated by either Staphylococcus aureus or yeast-derived zymosan beads was shown to depend on members of the Src kinase family as well as Btk. Src kinases were found to act upstream of Btk, phosphatidylinositol 3-kinase, phospholipase Cγ2 and the MAP kinases ERK and p38, thereby affecting all branches of the signalling investigated. In contrast, Btk was not involved in the activation of the MAP-kinases. Since the cytosolic phospholipase A2 in macrophages is regulated by both phosphorylation (via ERK and p38 and an increase in intracellular Ca2+, we propose that members of the Src kinase family are involved in both types of regulation, while the role of Btk may be restricted to the latter type. Conclusion Arachidonate release

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

    Energy Technology Data Exchange (ETDEWEB)

    Magnusson, Lisa U.; Lundqvist, Annika [Sahlgrenska Center for Cardiovascular and Metabolic Research, Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg (Sweden); Asp, Julia [Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg (Sweden); Synnergren, Jane [Systems Biology Research Center, School of Life Sciences, University of Skoevde, Skoevde (Sweden); Johansson, Cecilia Thalen [Sahlgrenska Center for Cardiovascular and Metabolic Research, Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg (Sweden); Palmqvist, Lars [Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg (Sweden); Jeppsson, Anders [Department of Cardiothoracic Surgery, Sahlgrenska University Hospital, Gothenburg (Sweden); Hulten, Lillemor Mattsson, E-mail: Lillemor.Mattsson@wlab.gu.se [Sahlgrenska Center for Cardiovascular and Metabolic Research, Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg (Sweden)

    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

  10. Ameliorative effects of polyunsaturated fatty acids against palmitic acid-induced insulin resistance in L6 skeletal muscle cells

    Directory of Open Access Journals (Sweden)

    Sawada Keisuke

    2012-03-01

    Full Text Available Abstract Background Fatty acid-induced insulin resistance and impaired glucose uptake activity in muscle cells are fundamental events in the development of type 2 diabetes and hyperglycemia. There is an increasing demand for compounds including drugs and functional foods that can prevent myocellular insulin resistance. Methods In this study, we established a high-throughput assay to screen for compounds that can improve myocellular insulin resistance, which was based on a previously reported non-radioisotope 2-deoxyglucose (2DG uptake assay. Insulin-resistant muscle cells were prepared by treating rat L6 skeletal muscle cells with 750 μM palmitic acid for 14 h. Using the established assay, the impacts of several fatty acids on myocellular insulin resistance were determined. Results In normal L6 cells, treatment with saturated palmitic or stearic acid alone decreased 2DG uptake, whereas unsaturated fatty acids did not. Moreover, co-treatment with oleic acid canceled the palmitic acid-induced decrease in 2DG uptake activity. Using the developed assay with palmitic acid-induced insulin-resistant L6 cells, we determined the effects of other unsaturated fatty acids. We found that arachidonic, eicosapentaenoic and docosahexaenoic acids improved palmitic acid-decreased 2DG uptake at lower concentrations than the other unsaturated fatty acids, including oleic acid, as 10 μM arachidonic acid showed similar effects to 750 μM oleic acid. Conclusions We have found that polyunsaturated fatty acids, in particular arachidonic and eicosapentaenoic acids prevent palmitic acid-induced myocellular insulin resistance.

  11. Effects of dietary fatty acids on the production and quality of eggs and larvae of Atlantic cod (Gadus morhua L.)

    DEFF Research Database (Denmark)

    Røjbek, Maria; Støttrup, Josianne; Jacobsen, Charlotte

    2014-01-01

    Cultivated Atlantic cod (Gadus morhua) entering their first year of gamete maturation were fed diets with different levels of arachidonic acid (ARA) and eicosapentaenoic acid (EPA) for 6.5 months prior to commencement of spawning. Gravid females were stripped three times: at the beginning, peak...

  12. FLUXES FOR MECHANIZED ELECTRIC WELDING,

    Science.gov (United States)

    WELDING FLUXES, WELDING ), (* WELDING , WELDING FLUXES), ARC WELDING , WELDS, STABILITY, POROSITY, WELDING RODS, STEEL, CERAMIC MATERIALS, FLUXES(FUSION), TITANIUM ALLOYS, ALUMINUM ALLOYS, COPPER ALLOYS, ELECTRODEPOSITION

  13. Nitro-fatty acids: novel anti-inflammatory lipid mediators

    Directory of Open Access Journals (Sweden)

    H. Rubbo

    2013-09-01

    Full Text Available Nitro-fatty acids are formed and detected in human plasma, cell membranes, and tissue, modulating metabolic as well as inflammatory signaling pathways. Here we discuss the mechanisms of nitro-fatty acid formation as well as their key chemical and biochemical properties. The electrophilic properties of nitro-fatty acids to activate anti-inflammatory signaling pathways are discussed in detail. A critical issue is the influence of nitroarachidonic acid on prostaglandin endoperoxide H synthases, redirecting arachidonic acid metabolism and signaling. We also analyze in vivo data supporting nitro-fatty acids as promising pharmacological tools to prevent inflammatory diseases.

  14. [Biology of essential fatty acids (EFA)].

    Science.gov (United States)

    Dobryniewski, Jacek; Szajda, Sławomir Dariusz; Waszkiewicz, Napoleon; Zwierz, Krzysztof

    2007-01-01

    Essential Fatty Acids (EFA), are unsaturated fatty acids not produced by human being, but essential for proper functioning of the human body. To EFA-s belongs: linoleic acid (LA) (18:2,cis detla(9,12), omega6)--precursor o f gamma-linolenic acid (GLA), gamma-linolenic acid (GLA) (18:3,cisA6,9,12, )6) and alpha-linolenic acid (ALA)(18:3,cisdelta(9, 12, 15), omega3)--product of dehydrogenation of linoleic acid (LA). Most important EFA is gamma-linolenic acid (GLA)--18 carbons, one-carboxylic, non-branched fatty acid with 3 double cis-bonds (the last is situated by 6-th carbon from methylic end). The diet devoided of EFA leads to decreased growth, skin and kidney injury and infertility. Modern research of GLA and others EFA's is concerned mainly on therapeutic impact on the inflammatory process. The biogenic amines, cytokines, prostaglandins, tromboxanes and leukotrienes are the main inflammatory mediators. The last three are described with the common name eicosanoides (eico-twenty). Eicosanoides are synthesized from 20-carbon unsaturated fatty acids: dihomo-gamma-linoleic (DGLA) (20:3, cis delta(8,11,14), omega6), arachidonic acid (AA-20:4, cis delta(5,8,11,14), omega6), and eicosapentaenoic acid (EPA-20:5, cis delta(5,8,11,14,17, omega3). Derivatives of gamma and gamma-linolenic acids regulate the inflammatory process, through their opposed activity. PG2, leucotrien C4 and tromboxan A2 have the strongest proinflammatory action. Derivatives of alpha-linolenic acid 15-HETE and prostaglandin E1 (PGE1) have weak pro-inflammatory action, or even anti-inflammatory (PGE1), and additionally, they inhibit the transformation of arachidonic acid (AA) to leukotriens. delta6-desaturase (transformes linolenic acid into gamma-linolenic acid by making additional double bond) is the slowest step of the fatty acid metabolism. It's activity is impaired by many physiological and pathologic factors and leads to gamma-linolenic acid (GLA) deficiency. The gamma-linolenic acid

  15. Patterns of Flux Emergence

    Science.gov (United States)

    Title, A.; Cheung, M.

    2008-05-01

    The high spatial resolution and high cadence of the Solar Optical Telescope on the JAXA Hinode spacecraft have allowed capturing many examples of magnetic flux emergence from the scale of granulation to active regions. The observed patterns of emergence are quite similar. Flux emerges as a array of small bipoles on scales from 1 to 5 arc seconds throughout the region that the flux eventually condenses. Because the fields emerging from the underlying flux rope my appear many in small segments and the total flux (absolute sum) is not a conserved quantity the amount of total flux on the surface may vary significantly during the emergence process. Numerical simulations of flux emergence exhibit patterns similar to observations. Movies of both observations and numerical simulations will be presented.

  16. Fatty acid composition of red blood cell membranes and risk of squamous cell carcinoma of the skin.

    Science.gov (United States)

    Harris, Robin B; Foote, Janet A; Hakim, Iman A; Bronson, Dan L; Alberts, David S

    2005-04-01

    Differential effects of fatty acids on carcinogenesis suggest that fatty acid composition is important in tumor development. Arachidonic acid and its metabolites elicit inflammation and promote tumor formation in mouse skin. Inhibitors of the arachidonic cascade inhibit tumor incidence. A population-based case control study in Southeastern Arizona tested the hypothesis that lower levels of arachidonic acid in RBC membranes were associated with decreased risk of skin squamous cell carcinoma (SCC; n = 335 SCC cases and 321 controls). Extracted and esterified RBC fatty acids were analyzed using capillary gas chromatography. Individual peaks for 14 fatty acids were measured as a percentage of total fatty acids. Logistic regression was used to estimate odds ratios (OR), adjusting for SCC risk factors (age, gender, actinic keratosis history, freckling, and tanning ability). Increased levels of arachidonic acid in RBC membranes were associated with increased risk of SCC [odds ratio (OR), 1.08 per mg/100 mL change; 95% confidence interval (95% CI), 1.02-1.15] and this association remained when controls with actinic keratosis precursor lesions were excluded. SCC risk was highest among the upper quartile of arachidonic acid (OR, 2.38; 95% CI, 1.37-4.12). In contrast, increasing proportions of palmitic acid (OR, 0.94; 95% CI, 0.89-1.00) and palmitoleicacid (OR, 0.49; 95% CI, 0.30-0.81) were associated with reduced SCC risk. More studies are needed to elucidate the function of RBC fatty acids so that recommendations can be made to alter the human diet for cancer prevention.

  17. Feedback Control of the Arachidonate Cascade in Osteoblastic Cells by 15-deoxy-Δ12,14-Prostaglandin J2

    Science.gov (United States)

    Ishino, Hidetaka; Kawahito, Yutaka; Tsubouchi, Yasunori; Kohno, Masataka; Wada, Makoto; Yamamoto, Aihiro; Hamaguchi, Masahide; Kadoya, Masatoshi; Tokunaga, Daisaku; Hojo, Tatsuya; Matsuyama, Masahide; Yoshimura, Rikio; Yoshikawa, Toshikazu

    2008-01-01

    15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) and an anti-diabetic thiazolidinedione, troglitazone (TRO) are peroxisome proliferator-activated receptor (PPAR)-γ ligands, which regulate immuno-inflammatory reactions as well as adipocyte differentiation. We previously reported that 15d-PGJ2 can suppress interleukin (IL)-1β-induced prostaglandin E2 (PGE2) synthesis in synoviocytes of rheumatoid arthritis (RA). IL-1 also stimulates PGE2 synthesis in osteoblasts by regulation of cyclooxygenase (COX)-2 and regulates osteoclastic bone resorption in various diseases such as RA and osteoporosis. In this study, we investigated the feedback mechanism of the arachidonate cascade in mouse osteoblastic cells, MC3T3-E1 cells, which differentiate into mature osteoblasts. Treatment with 15d-PGJ2 led to a significant increase in IL-1α-induced COX-2 expression and PGE2 production in a dose dependent manner. The effect of 15d-PGJ2 was stronger than that of TRO. However, it did not affect the expression of COX-1. In addition, cell viability of MC3T3-E1 cells was not changed in the condition we established. This means that 15d-PGJ2 exerts a positive feedback regulation of the arachidonate cascade of PGE2 in osteoblastic cells. These results may provide important information about the pathogenesis and treatment of bone resorption in a variety of diseases such as RA and osteoporosis. PMID:18231633

  18. The dominant glutamic acid metabolic flux to produce γ-amino butyric acid over proline in Nicotiana tabacum leaves under water stress relates to its significant role in antioxidant activity.

    Science.gov (United States)

    Liu, Cuili; Zhao, Li; Yu, Guanghui

    2011-08-01

    γ-Amino butyric acid (GABA) and proline play a crucial role in protecting plants during various environmental stresses. Their synthesis is from the common precursor glutamic acid, which is catalyzed by glutamate decarboxylase and Δ(1) -pyrroline-5-carboxylate synthetase respectively. However, the dominant pathway under water stress has not yet been established. To explore this, excised tobacco leaves were used to simulate a water-stress condition. The results showed GABA content was much higher than that of proline in leaves under water-deficit and non-water-deficit conditions. Specifically, the amount of GABA significantly increased compared to proline under continuous water loss for 16 h, indicating that GABA biosynthesis is the dominant pathway from glutamic acid metabolism under these conditions. Quantitative reverse transcription polymerase chain reaction and protein Western gel-blot analysis further confirmed this. To explore the function of GABA accumulation, a system producing superoxide anion (O(2) (-) ), peroxide hydrogen (H(2) O(2) ), and singlet oxygen ((1) O(2) ) was employed to investigate the scavenging role on free-radical production. The results demonstrated that the scavenging ability of GABA for O(2) (-) , H(2) O(2) , and (1) O(2) was significantly higher than that of proline. This indicated that GABA acts as an effective osmolyte to reduce the production of reactive oxygen species under water stress.

  19. A plasma membrane-targeted cytosolic domain of STIM1 selectively activates ARC channels, an arachidonate-regulated store-independent Orai channel.

    Science.gov (United States)

    Thompson, Jill L; Shuttleworth, Trevor J

    2012-01-01

    The Orai family of calcium channels includes the store-operated CRAC channels and store-independent, arachidonic acid (AA)-regulated ARC channels. Both depend on STIM1 for their activation but, whereas CRAC channel activation involves sensing the depletion of intracellular calcium stores via a luminal N terminal EF-hand of STIM1 in the endoplasmic reticulum (ER) membrane, ARC channels are exclusively activated by the pool of STIM1 that constitutively resides in the plasma membrane (PM). Here, the EF-hand is extracellular and unlikely to ever lose its bound calcium, suggesting that STIM1-dependent activation of ARC channels is very different from that of CRAC channels. We now show that attachment of the cytosolic portion of STIM1 to the inner face of the PM via an N terminal Lck-domain sequence is sufficient to enable normal AA-dependent activation of ARC channels, while failing to allow activation of store-operated CRAC channels. Introduction of a point mutation within the Lck-domain resulted in the loss of both PM localization and ARC channel activation. Reversing the orientation of the PM-anchored STIM1 C terminus via a C-terminal CAAX-box fails to support either CRAC or ARC channel activation. Finally, the Lck-anchored STIM1 C-terminal domain also enabled the exclusive activation of the ARC channels following physiological agonist addition. These data demonstrate that simple tethering of the cytosolic C-terminal domain of STIM1 to the inner face of the PM is sufficient to allow the full, normal and exclusive activation of ARC channels, and that the N-terminal regions of STIM1 (including the EF-hand domain) play no significant role in this activation.

  20. Release of arachidonic and linoleic acid metabolites in skin organ cultures as characteristics of in vitro skin irritancy

    NARCIS (Netherlands)

    Sandt, J.J.M. van de; Maas, W.J.M.; Doornink, P.C.; Rutten, A.A.J.J.L.

    1995-01-01

    In vitro techniques make a major contribution to the development of alternatives to the in vivo 'Draize' skin irritation test, and the development of sensitive and generally applicable in vitro endpoints of cutaneous toxicity is an area of intensive research. To investigate in vitro characteristics

  1. Release of arachidonic and linoleic acid metabolites in skin organ cultures as characteristics of in vitro skin irritancy

    NARCIS (Netherlands)

    Sandt, J.J.M. van de; Maas, W.J.M.; Doornink, P.C.; Rutten, A.A.J.J.L.

    1995-01-01

    In vitro techniques make a major contribution to the development of alternatives to the in vivo 'Draize' skin irritation test, and the development of sensitive and generally applicable in vitro endpoints of cutaneous toxicity is an area of intensive research. To investigate in vitro characteristics

  2. Calcium ionophore (A-23187 induced peritoneal eicosanoid biosynthesis: a rapid method to evaluate inhibitors of arachidonic acid metabolism in vivo

    Directory of Open Access Journals (Sweden)

    T. S. Rao

    1993-01-01

    Full Text Available The present investigation characterizes calcium ionophore (A-23187 induced peritoneal eicosanoid biosynthesis in the rat. Intraperitoneal injection of A-23187 (20 μg/rat stimulated marked biosynthesis of 6-keto-PGF1α (6-KPA, TxB2, LTC4 and LTB4, with no detectable changes on levels of PGE2. Levels of all eicosanoids decreased rapidly after a peak which was seen as early as 5 min. Enzyme markers of cellular contents of neutrophils and mononuclear cells, MPO and NAG respectively, decreased rapidly after ionophore injection; this was followed by increases after 60 min. Indomethacin, a selective cyclooxygenase inhibitor, and zileuton and ICI D-2138, two selective 5-lipoxygenase inhibitors attenuated prostaglandin and leukotriene pathways respectively. Oral administration of zileuton (20 mg/kg, p.o. inhibited LTB4 biosynthesis for up to 6 h suggesting a long duration of pharmacological activity in the rats consistent with its longer half-life. The rapid onset and the magnitude of increases in levels of eicosanoids render the ionophore induced peritoneal eicosanoid biosynthesis a useful model to evaluate pharmacological profiles of inhibitors of eicosanoid pathways in vivo.

  3. Long-Term Effect of Docosahexaenoic Acid Feeding on Lipid Composition and Brain Fatty Acid-Binding Protein Expression in Rats

    OpenAIRE

    2015-01-01

    Arachidonic (AA) and docosahexaenoic acid (DHA) brain accretion is essential for brain development. The impact of DHA-rich maternal diets on offspring brain fatty acid composition has previously been studied up to the weanling stage; however, there has been no follow-up at later stages. Here, we examine the impact of DHA-rich maternal and weaning diets on brain fatty acid composition at weaning and three weeks post-weaning. We report that DHA supplementation during lactation maintains high DH...

  4. The function of very long chain polyunsaturated fatty acids in the pineal gland.

    Science.gov (United States)

    Catalá, Angel

    2010-02-01

    The mammalian pineal gland is a prominent secretory organ with a high metabolic activity. Melatonin (N-acetyl-5-methoxytryptamine), the main secretory product of the pineal gland, efficiently scavenges both the hydroxyl and peroxyl radicals counteracting lipid peroxidation in biological membranes. Approximately 25% of the total fatty acids present in the rat pineal lipids are represented by arachidonic acid (20:4n-6) and docosahexaenoic acid (22:6n-3). These very long chain polyunsaturated fatty acids play important roles in the pineal gland. In addition to the production of melatonin, the mammalian pineal gland is able of convert these polyunsaturated fatty acids into bioactive lipid mediators. Lipoxygenation is the principal lipoxygenase (LOX) activity observed in the rat pineal gland. Lipoxygenation in the pineal gland is exceptional because no other brain regions express significant LOX activities under normal physiological conditions. The rat pineal gland expresses both 12- and 15-lipoxygenase (LOX) activities, producing 12- and 15-hydroperoxyeicosatetraenoic acid (12- and 15-HpETE) from arachidonic acid and 14- and 17-hydroxydocosahexaenoic acid (14- and 17-HdoHE) from docosahexaenoic acid, respectively. The rat pineal also produces hepoxilins via LOX pathways. The hepoxilins are bioactive epoxy-hydroxy products of the arachidonic acid metabolism via the 12S-lipoxygenase (12S-LOX) pathway. The two key pineal biochemical functions, lipoxygenation and melatonin synthesis, may be synergistically regulated by the status of n-3 essential fatty acids.

  5. Metabolic flux analysis of propionic acid biosynthesis with two immobilized cell reactors fermentation by Propionibacterium%丙酸杆菌的两种固定化细胞反应器发酵生产丙酸及其代谢通量分析

    Institute of Scientific and Technical Information of China (English)

    陈飞; 冯小海; 吴波; 李莎; 徐虹

    2011-01-01

    根据构建的费氏丙酸杆菌合成丙酸的生化反应网络,利用代谢通量分析法分析了课题组构建的两种固定化细胞反应器对丙酸发酵的影响.结果表明,固定化细胞发酵可以调节葡萄糖-6-磷酸、磷酸烯醇式丙酮酸和丙酮酸节点处的代谢通量分布,从而最终影响生物量和各种有机酸的合成.与游离发酵相比,两种固定化发酵方式戊糖磷酸途径通最都有显著提高,乙酸和乳酸通量均有减少.与植物纤维床反应器主要靠直接加强丙酸合成途径使丙酸产率提高了242.72%不同,多点式棉纤维床反应器发酵主要是通过琥珀酸合成途径的增强而使丙酸产率提高了56.80%.比较了相关关键酶的比活.酶活变化与代谢通量结果基本一致.%The metabolic network of Propionibacterium freudenreichii CCTCC M207015 for propionic acid biosynthesis, with glucose as the sole carbon source, was built based on the stoichiometric balance equations to illustrate the carbon flux distribution of intermediates and metabolites. The propionic acid production with two immobilized cell reactors fermentation was studied by using the metabolic flux analysis method. The results showed that the flux distribution of nodes of glucose 6-phosphate, phosphoenolpyruvate and pyruvate changed after immobilized cells fermentation regulation. Compared with free cells fermentation, the flux of HMP of the two immobilized cells fermentation significantly increased, also with decrease fluxes of acetic acid and lactic acid. The productivity of propionic acid in plant fibrous-bed reactor fermentation increased 242.72% mainly by directly enhancing propionic acid synthesis pathway, while in the multi-point fibrous-bed reactor fermentation it increased 56.80% through the enhancement of succinic acid biosynthetic pathway, and the relevant key enzyme activity and metabolic flux variation had good consistency.

  6. Trans isomeric octadecenoic acids are related inversely to arachidonic acid and DHA and positively related to mead acid in umbilical vessel wall lipids

    NARCIS (Netherlands)

    Decsi, T; Boehm, G; Tjoonk, HMR; Molnar, S; Dijck-Brouwer, DAJ; Hadders-Algra, M; Martini, IA; Muskiet, FAJ; Boersma, ER

    2002-01-01

    Long-chain PUFA play an important role in early human neurodevelopment. Significant inverse correlations were reported between values of trans isomeric and long-chain PUFA in plasma lipids of preterm infants and children aged 1-15 yr as well as in venous cord blood lipids of full-term infants. Here

  7. Prompt atmospheric neutrino flux

    CERN Document Server

    Jeong, Yu Seon; Enberg, Rikard; Kim, C S; Reno, Mary Hall; Sarcevic, Ina; Stasto, Anna

    2016-01-01

    We evaluate the prompt atmospheric neutrino flux including nuclear correction and $B$ hadron contribution in the different frameworks: NLO perturbative QCD and dipole models. The nuclear effect is larger in the prompt neutrino flux than in the total charm production cross section, and it reduces the fluxes by $10\\% - 30\\%$ depending on the model. We also investigate the uncertainty using the QCD scales allowed by the charm cross section data from RHIC and LHC experiments.

  8. Urinary prostaglandin E and vasopressin excretion in essential fatty acid-deficient rats

    DEFF Research Database (Denmark)

    Hansen, Harald S.; Jensen, B.

    1983-01-01

    and the (n-3) rats, even though large differences were found in the percentage of arachidonic acid (20:4[n-6]), icosapentaenoic acid (20:5[n-3]), and icosatrienoic acid (20:3[n-9]) of total kidney fatty acids as well as of kidney phosphatidylinositol fatty acids. Fractionation of urine extracts on high...... excretion of prostaglandin E (PGE), immunoreactive arginine vasopressin (iA VP), and kallikrein were determined. PGE was quantitated with a radioimmunoassay having 4.9% cross-reactivity with prostaglandin E (PGE). After 4 weeks on the diet, water consumption and urinary iAVP excretion increased...... an arachidonic acid pool, which is rather resistant to restriction in dietary linoleate. © 1983 American Oil Chemists' Society (AOCS)....

  9. Alpha-synuclein gene ablation increases docosahexaenoic acid incorporation and turnover in brain phospholipids

    DEFF Research Database (Denmark)

    Golovko, Mikhail Y; Rosenberger, Thad A; Feddersen, Søren

    2007-01-01

    Previously, we demonstrated that ablation of alpha-synuclein (Snca) reduces arachidonate (20:4n-6) turnover in brain phospholipids through modulation of an endoplasmic reticulum-localized acyl-CoA synthetase (Acsl). The effect of Snca ablation on docosahexaenoic acid (22:6n-3) metabolism is unkno...

  10. Video Meteor Fluxes

    Science.gov (United States)

    Campbell-Brown, M. D.; Braid, D.

    2011-01-01

    The flux of meteoroids, or number of meteoroids per unit area per unit time, is critical for calibrating models of meteoroid stream formation and for estimating the hazard to spacecraft from shower and sporadic meteors. Although observations of meteors in the millimetre to centimetre size range are common, flux measurements (particularly for sporadic meteors, which make up the majority of meteoroid flux) are less so. It is necessary to know the collecting area and collection time for a given set of observations, and to correct for observing biases and the sensitivity of the system. Previous measurements of sporadic fluxes are summarized in Figure 1; the values are given as a total number of meteoroids striking the earth in one year to a given limiting mass. The Gr n et al. (1985) flux model is included in the figure for reference. Fluxes for sporadic meteoroids impacting the Earth have been calculated for objects in the centimeter size range using Super-Schmidt observations (Hawkins & Upton, 1958); this study used about 300 meteors, and used only the physical area of overlap of the cameras at 90 km to calculate the flux, corrected for angular speed of meteors, since a large angular speed reduces the maximum brightness of the meteor on the film, and radiant elevation, which takes into account the geometric reduction in flux when the meteors are not perpendicular to the horizontal. They bring up corrections for both partial trails (which tends to increase the collecting area) and incomplete overlap at heights other than 90 km (which tends to decrease it) as effects that will affect the flux, but estimated that the two effects cancelled one another. Halliday et al. (1984) calculated the flux of meteorite-dropping fireballs with fragment masses greater than 50 g, over the physical area of sky accessible to the MORP fireball cameras, counting only observations in clear weather. In the micron size range, LDEF measurements of small craters on spacecraft have been used to

  11. Effects of Fatty Acids on Intracellular [Ca2+], Mitochondrial Uncoupling and Apoptosis in Rat Pachytene Spermatocytes and Round Spermatids.

    Directory of Open Access Journals (Sweden)

    Joaquín Paillamanque

    Full Text Available The aim of this work was to explore the ability of free arachidonic acid, palmitic acid and the unsaturated fatty acids oleic acid and docosahexaenoic acid to modify calcium homeostasis and mitochondrial function in rat pachytene spermatocytes and round spermatids. In contrast to palmitic acid, unsaturated fatty acids produced significant increases in intracellular calcium concentrations ([Ca2+]i in both cell types. Increases were fatty acid specific, dose-dependent and different for each cell type. The arachidonic acid effects on [Ca2+]i were higher in spermatids than in spermatocytes and persisted when residual extracellular Ca2+ was chelated by EGTA, indicating that the increase in [Ca2+]i originated from release of intracellular calcium stores. At the concentrations required for these increases, unsaturated fatty acids produced no significant changes in the plasma membrane potential of or non-specific permeability in spermatogenic cells. For the case of arachidonic acid, the [Ca2+]i increases were not caused by its metabolic conversion to eicosanoids or anandamide; thus we attribute this effect to the fatty acid itself. As estimated with fluorescent probes, unsaturated fatty acids did not affect the intracellular pH but were able to induce a progressive decrease in the mitochondrial membrane potential. The association of this decrease with reduced reactive oxygen species (ROS production strongly suggests that unsaturated fatty acids induced mitochondrial uncoupling. This effect was stronger in spermatids than in spermatocytes. As a late event, arachidonic acid induced caspase 3 activation in a dose-dependent manner both in the absence and presence of external Ca2+. The concurrent but differential effects of unsaturated fatty acids on [Ca2+]i and mitochondrial functions are additional manifestations of the metabolic changes that germ cells undergo during their differentiation.

  12. Les rôles physiologiques majeurs exercés par les acides gras polyinsaturés (AGPI)

    OpenAIRE

    Guesnet Philippe; Alessandri Jean-Marc; Astorg Pierre; Pifferi Fabien; Lavialle Monique

    2005-01-01

    Polyunsaturated fatty acids (PUFAs) are essential nutrients for mammals and the human species, and belong to either of two distinct and not interconvertible series, omega 6 and omega 3. The metabolic precursors of these two series, linoleic and α-linolenic acids respectively, are the dietary essential fatty acids. These two fatty acids, once absorbed, lead to the specific synthesis and incorporation in practically all cell membranes of long-chain active PUFA derivatives such as arachidonic ac...

  13. Long-chain n-3 fatty acids and inflammation: potential application in surgical and trauma patients

    Directory of Open Access Journals (Sweden)

    Calder P.C.

    2003-01-01

    Full Text Available Lipids used in nutritional support of surgical or critically ill patients have been based on soybean oil, which is rich in the n-6 fatty acid linoleic acid (18:2n-6. Linoleic acid is the precursor of arachidonic acid (20:4n-6. In turn, arachidonic acid in cell membrane phospholipids is the substrate for the synthesis of a range of biologically active compounds (eicosanoids including prostaglandins, thromboxanes, and leukotrienes. These compounds can act as mediators in their own right and can also act as regulators of other processes, such as platelet aggregation, blood clotting, smooth muscle contraction, leukocyte chemotaxis, inflammatory cytokine production, and immune function. There is a view that an excess of n-6 fatty acids should be avoided since this could contribute to a state where physiological processes become dysregulated. One alternative is the use of fish oil. The rationale of this latter approach is that fish oil contains long chain n-3 fatty acids, such as eicosapentaenoic acid. When fish oil is provided, eicosapentaenoic acid is incorporated into cell membrane phospholipids, partly at the expense of arachidonic acid. Thus, there is less arachidonic acid available for eicosanoid synthesis. Hence, fish oil decreases production of prostaglandins like PGE2 and of leukotrienes like LTB4. Thus, n-3 fatty acids can potentially reduce platelet aggregation, blood clotting, smooth muscle contraction, and leukocyte chemotaxis, and can modulate inflammatory cytokine production and immune function. These effects have been demonstrated in cell culture, animal feeding and healthy volunteer studies. Fish oil decreases the host metabolic response and improves survival to endotoxin in laboratory animals. Recently clinical studies performed in various patient groups have indicated benefit from this approach.

  14. [Phospholipid and fatty acid content of the blood of sheep infected with the nematode Dictyocaulus filaria].

    Science.gov (United States)

    Kuchbaev, A E; Bastarbekova, G M

    2001-01-01

    The results of analysis of phospholipids (PL) and fatty acid content in the blood of sheep infected with the nematodes Dictyocaulus filaria are displayed. A significant increase of lysophosphatidylcholine and arachidonic acid as well as a decrease of docozagexaenic acid in PL of infected sheep have been recorded. That points out to structural and functional disorders of cellular membranes during the infection. These disorder could be used as a metabolic criterion to estimate the relationships within the host-parasite system examined.

  15. Electron heat flux instability

    Science.gov (United States)

    Saeed, Sundas; Sarfraz, M.; Yoon, P. H.; Lazar, M.; Qureshi, M. N. S.

    2017-02-01

    The heat flux instability is an electromagnetic mode excited by a relative drift between the protons and two-component core-halo electrons. The most prominent application may be in association with the solar wind where drifting electron velocity distributions are observed. The heat flux instability is somewhat analogous to the electrostatic Buneman or ion-acoustic instability driven by the net drift between the protons and bulk electrons, except that the heat flux instability operates in magnetized plasmas and possesses transverse electromagnetic polarization. The heat flux instability is also distinct from the electrostatic counterpart in that it requires two electron species with relative drifts with each other. In the literature, the heat flux instability is often called the 'whistler' heat flux instability, but it is actually polarized in the opposite sense to the whistler wave. This paper elucidates all of these fundamental plasma physical properties associated with the heat flux instability starting from a simple model, and gradually building up more complexity towards a solar wind-like distribution functions. It is found that the essential properties of the instability are already present in the cold counter-streaming electron model, and that the instability is absent if the protons are ignored. These instability characteristics are highly reminiscent of the electron firehose instability driven by excessive parallel temperature anisotropy, propagating in parallel direction with respect to the ambient magnetic field, except that the free energy source for the heat flux instability resides in the effective parallel pressure provided by the counter-streaming electrons.

  16. CO2 flux geothermometer for geothermal exploration

    Science.gov (United States)

    Harvey, M. C.; Rowland, J. V.; Chiodini, G.; Rissmann, C. F.; Bloomberg, S.; Fridriksson, T.; Oladottir, A. A.

    2017-09-01

    A new geothermometer (TCO2 Flux) is proposed based on soil diffuse CO2 flux and shallow temperature measurements made on areas of steam heated, thermally altered ground above active geothermal systems. This CO2 flux geothermometer is based on a previously reported CO2 geothermometer that was designed for use with fumarole analysis. The new geothermometer provides a valuable additional exploration tool for estimating subsurface temperatures in high-temperature geothermal systems. Mean TCO2 Flux estimates fall within the range of deep drill hole temperatures at Wairakei (New Zealand), Tauhara (New Zealand), Rotokawa (New Zealand), Ohaaki (New Zealand), Reykjanes (Iceland) and Copahue (Argentina). The spatial distribution of geothermometry estimates is consistent with the location of major upflow zones previously reported at the Wairakei and Rotokawa geothermal systems. TCO2 Flux was also evaluated at White Island (New Zealand) and Reporoa (New Zealand), where limited sub-surface data exists. Mode TCO2 Flux at White Island is high (320 °C), the highest of the systems considered in this study. However, the geothermometer relies on mineral-water equilibrium in neutral pH reservoir fluids, and would not be reliable in such an active and acidic environment. Mean TCO2 Flux at Reporoa (310 °C) is high, which indicates Reporoa has a separate upflow from the nearby Waiotapu geothermal system; an outflow from Waiotapu would not be expected to have such high temperature.

  17. Inhibitors of arachidonate-regulated calcium channel signaling suppress triggered activity induced by the late sodium current.

    Science.gov (United States)

    Wolkowicz, Paul; Umeda, Patrick K; Sharifov, Oleg F; White, C Roger; Huang, Jian; Mahtani, Harry; Urthaler, Ferdinand

    2014-02-05

    Disturbances in myocyte calcium homeostasis are hypothesized to be one cause for cardiac arrhythmia. The full development of this hypothesis requires (i) the identification of all sources of arrhythmogenic calcium and (ii) an understanding of the mechanism(s) through which calcium initiates arrhythmia. To these ends we superfused rat left atria with the late sodium current activator type II Anemonia sulcata toxin (ATXII). This toxin prolonged atrial action potentials, induced early afterdepolarization, and provoked triggered activity. The calmodulin-dependent protein kinase II (CaMKII) inhibitor KN-93 (N-[2-[[[3-(4-chlorophenyl)-2-propenyl]methylamino]methyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenzenesulphon-amide) suppressed ATXII triggered activity but its inactive congener KN-92 (2-[N-(4-methoxy benzenesulfonyl)]amino-N-(4-chlorocinnamyl)-N-methylbenzylamine) did not. Neither drug affected normal atrial contractility. Calcium entry via L-type channels or calcium leakage from sarcoplasmic reticulum stores are not critical for this type of ectopy as neither verapamil ((RS)-2-(3,4-dimethoxyphenyl)-5-{[2-(3,4-dimethoxyphenyl)ethyl]-(methyl)amino}-2-prop-2-ylpentanenitrile) nor ryanodine affected ATXII triggered activity. By contrast, inhibitors of the voltage independent arachidonate-regulated calcium (ARC) channel and the store-operated calcium channel specifically suppressed ATXII triggered activity without normalizing action potentials or affecting atrial contractility. Inhibitors of cytosolic calcium-dependent phospholipase A2 also suppressed triggered activity suggesting that this lipase, which generates free arachidonate, plays a key role in ATXII ectopy. Thus, increased left atrial late sodium current appears to activate atrial Orai-linked ARC and store operated calcium channels, and these voltage-independent channels may be unexpected sources for the arrhythmogenic calcium that underlies triggered activity.

  18. Lipid malnutrition of patients with liver cirrhosis: effect of low intake of dietary lipid on plasma fatty acid composition.

    Directory of Open Access Journals (Sweden)

    Okita,Misako

    1989-02-01

    Full Text Available The plasma fatty acid composition of cirrhotic patients and their dietary intake of fatty acids were determined. Significantly lower plasma arachidonic, docosahexaenoic, dihomo-gamma-linolenic and eicosapentaenoic acid levels were observed in cirrhotic patients than in healthy controls. A remarkably low dietary intake of polyunsaturated fatty acids supplied from fish, vegetable oil and pulses was shown in cirrhotic patients. Positive correlations were observed between plasma arachidonic acid concentrations and clearance rate of indocyanine green (KICG (r = 0.826, p less than 0.05 and between dihomo-gamma-linolenic acid levels and cholinesterase activities (r = 0.841, p less than 0.05. From these results, we conclude that a supply of polyunsaturated fatty acids is necessary for the nutritional treatment of patients with liver cirrhosis.

  19. Enhancement of neutrophil-mediated killing of Plasmodium falciparum asexual blood forms by fatty acids: importance of fatty acid structure.

    Science.gov (United States)

    Kumaratilake, L M; Ferrante, A; Robinson, B S; Jaeger, T; Poulos, A

    1997-10-01

    Effects of fatty acids on human neutrophil-mediated killing of Plasmodium falciparum asexual blood forms were investigated by using a quantitative radiometric assay. The results showed that the antiparasitic activity of neutrophils can be greatly increased (>threefold) by short-term treatment with fatty acids with 20 to 24 carbon atoms and at least three double bonds. In particular, the n-3 polyenoic fatty acids, eicosapentaenoic and docosahexaenoic acids, and the n-6 fatty acid, arachidonic acid, significantly enhanced neutrophil antiparasitic activity. This effect was >1.5-fold higher than that induced by an optical concentration of the know