D-2 dopamine receptor activation reduces free [3H]arachidonate release induced by hypophysiotropic peptides in anterior pituitary cells

International Nuclear Information System (INIS)

Canonico, P.L.

1989-01-01

Dopamine reduces the stimulation of intracellular [ 3 H]arachidonate release produced by the two PRL-stimulating peptides angiotensin-II and TRH. This effect is concentration dependent and is mediated by stimulation of D-2 dopamine receptors. D-2 receptor agonists (bromocriptine, dihydroergocryptine, and dihydroergocristine) inhibit the release of fatty acid induced by angiotensin-II with a potency that parallels their ability to inhibit PRL release in vitro. Conversely, the selective D-2 receptor antagonist L-sulpiride completely prevents dopamine's effect, whereas SCH 23390 (a D-1 receptor antagonist) is ineffective. The inhibitory action of dopamine does not seem to be consequent to an action on the adenylate cyclase-cAMP system, as 8-bromo-cAMP (1 mM) does not affect either basal or dopamine-inhibited [ 3 H]arachidonate release. However, a 24-h pertussis toxin pretreatment significantly reduces the action of dopamine on fatty acid release. Collectively, these results suggest that D-2 dopamine receptor-mediated inhibition of intracellular [ 3 H]arachidonate release requires the action of a GTP-binding protein, but is not a consequence of an inhibitory action on cAMP levels

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

International Nuclear Information System (INIS)

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

1986-01-01

Human keratinocytes in culture were labelled with 14 C-dihomo-gamma-linolenic acid, 14 C-arachidonic acid or 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

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

glutamate and sPLA2 from bee venom. sPLA2, at concentrations eliciting low neurotoxicity (acid into triacylglycerols. Free [3H]arachidonic acid accumulated at higher enzyme concentrations......, from Taipan snake venom. The NMDA receptor antagonist MK-801 blocked glutamate effects and partially inhibited sPLA2 OS2 but not sPLA2 from bee venom-induced arachidonic acid release. Thus, the synergy with glutamate and very low concentrations of exogenously added sPLA2 suggests a potential role......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...

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

International Nuclear Information System (INIS)

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

1990-01-01

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

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

International Nuclear Information System (INIS)

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

1986-01-01

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

Dietary arachidonic acid in perinatal nutrition

DEFF Research Database (Denmark)

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 lev...

Nitric oxide production from macrophages is regulated by arachidonic acid metabolites.

Science.gov (United States)

Imai, Y; Kolb, H; Burkart, V

1993-11-30

In activated macrophages the inducible form of the enzyme nitric oxide (NO) synthase generates high amounts of the toxic mediator NO. After 20 h of treatment with LPS rat peritoneal macrophages release 12-16 nmol NO2-/10(5) cells which is detectable in the culture supernatant by the Griess reaction as a measure of NO formation. The addition of aminoguanidine (1 mM), a preferential inhibitor of the inducible NO-synthase, completely abolished NO2-accumulation. Incubation with indomethacin or acetyl-salicylic acid, preferential inhibitors of the cyclooxygenase pathway of the arachidonic acid metabolism, did not influence NO2- levels. Nordihydro-guaiaretic acid (50 microM), a preferential inhibitor of the lipoxygenase pathway, caused strong reduction of NO2- accumulation to 1.9 +/- 0.3 nmol/200 microliter. Simultaneous inhibition of cyclo- and lipoxygenase by BW755c resulted in an intermediate effect (7.3 +/- 1.1 nmol/200 microliter NO2-). These results show that the induction of NO production in activated macrophages is regulated by products of the lipoxygenase-pathway of the arachidonic acid metabolism.

Role of arachidonic acid metabolism in transcriptional induction of tumor necrosis factor gene expression by phorbol ester

Energy Technology Data Exchange (ETDEWEB)

Horiguchi, J.; Spriggs, D.; Imamura, K.; Stone, R.; Luebbers, R.; Kufe, D.

1989-01-01

The treatment of human HL-60 promyelocytic leukemia cells with 12-0 tetradecanoylphorbol-13-acetate (TPA) is associated with induction of tumor necrosis factor (TNF) transcripts. The study reported here has examined TPA-induced signaling mechanisms responsible for the regulation of TNF gene expression in these cells. Run-on assays demonstrated that TPA increases TNS mRNA levels by transcriptional activation of this gene. The induction of TNF transcripts by TPA was inhibited by the isoquinolinesulfonamide derivative H7 but not by HA1004, suggesting that this effect of TPA is mediated by activation of protein kinase C. TPA treatment also resulted in increased arachidonic acid release. Moreover, inhibitors of phospholipase, A/sub 2/ blocked both the increase in arachidonic acid release and the induction of TNF transcripts. These findings suggest that TPA induces TNF gene expression through the formation of arachidonic acid metabolites. Although indomethacin had no detectable effect on this induction of TNF transcripts, ketoconazole, an inhibitor of 5-lipoxygenase, blocked TPA-induced increases in TNF mRNA levels. Moreover, TNF mRNA levels were increased by the 5-lipoxygenase metabolite leukotriene B/sub 4/. In contrast, the cyclooxygenase metabolite prostaglandin E/sub 2/ inhibited the induction of TNF transcripts by TPA. Taken together, these results suggest that TPA induces TNF gene expression through the arachidonic acid cascade and that the level of TNF transcripts is regulated by metabolites of the pathway, leukotriene B/sub 4/ and prostaglandin E/sub 2/.

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

The influence of arachidonic acid metabolites on cell division in the intestinal epithelium and in colonic tumors.

Science.gov (United States)

Petry, F M; Tutton, P J; Barkla, D H

1984-09-01

Various metabolites of arachidonic acid are now known to influence cell division. In this paper the effects on cell proliferation of arachidonic acid, some inhibitors of arachidonic acid metabolism and some analogs of arachidonic acid metabolites is described. The epithelial cell proliferation rate in the jejunum, in the descending colon and in dimethylhydrazine-induced tumors of rat colon was measured using a stathmokinetic technique. Administration of arachidonic acid resulted in retardation of cell proliferation in each of the tissues examined. A cyclooxygenase inhibitor (Flurbiprofen) prevented this effect of arachidonic acid in the jejunal crypts and in colonic tumors, but not in colonic crypts. In contrast, inhibitors of both cyclooxygenase and lipoxygenase (Benoxaprofen and BW755c) prevented the effect of arachidonic acid in the colonic crypts and reduced its effect on colonic tumours but did not alter its effect on the jejunum. An inhibitor of thromoboxane A2 synthetase (U51,605) was also able to prevent the inhibitory effect of arachidonic acid on colonic tumors. Treatment with 16,16-dimethyl PGE2 inhibited cell proliferation in jejunal crypts and in colonic tumors, as did a thromboxane A2 mimicking agent, U46619. Nafazatrom, an agent that stimulates prostacyclin synthesis and inhibits lypoxygenase, promoted cell proliferation in the jejunal crypts and colonic crypts, but inhibited cell proliferation in colonic tumours.

The effect of the antipsoriatic drug metabolite etretin (Ro 10-1670) on UVB irradiation induced changes in the metabolism of arachidonic acid in human keratinocytes in culture

International Nuclear Information System (INIS)

Punnonen, Kari; Jansen, C.T.; Puustinen, Tapio

1986-01-01

[ 14 C]Arachidonic acid was avidly incorporated into human keratinocytes in culture and following exposure to UVB irradiation of 9 mJ/cm 2 (erythemally effective, EE) substantial amounts of 14 C-radiolabel were released from the cells. The release of radiolabel was accompanied by a decrease in the labelling of phosphatidylethanolamine whereas the labelling of triacylglycerols and cholesteryl esters was increased. Keratinocytes produced significant amounts of prostaglandin E 2 (PGE 2 ) and following UVB irradiation of 9 mJ/cm 2 (EE) the formation of prostaglandin E 2 was increased. Etretin (Ro 10-1670), the active metabolite of the antipsoriatic drug etretinate (Ro 10-9359), affected significantly neither the total release of radiolabel induced by UVB nor the formation of prostaglandin E 2 . However, in the presence of etretin the UVB irradiation induced transfer of [ 14 C]arachidonic acid into triacylglycerols and cholesteryl esters was not increased as much as in the corresponding experiments without etretin. On the basis of the present study it appears that etretin dose not interfere with the release of arachidonic acid in amounts which could be related to the therapeutic effects of the combination of retinoids with UVB irradiation (Re-UVB) in the treatment of psoriasis. (author)

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.

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

Phospholipid sources for adrenic acid mobilization in RAW 264.7 macrophages. Comparison with arachidonic acid.

Science.gov (United States)

Guijas, Carlos; Astudillo, Alma M; Gil-de-Gómez, Luis; Rubio, Julio M; Balboa, María A; Balsinde, Jesús

2012-11-01

Cells metabolize arachidonic acid (AA) to adrenic acid (AdA) via 2-carbon elongation reactions. Like AA, AdA can be converted into multiple oxygenated metabolites, with important roles in various physiological and pathophysiological processes. However, in contrast to AA, there is virtually no information on how the cells regulate the availability of free AdA for conversion into bioactive products. We have used a comparative lipidomic approach with both gas chromatography and liquid chromatography coupled to mass spectrometry to characterize changes in the levels of AA- and AdA-containing phospholipid species in RAW 264.7 macrophage-like cells. Incubation of the cells with AA results in an extensive conversion to AdA but both fatty acids do not compete with each other for esterification into phospholipids. AdA but not AA, shows preference for incorporation into phospholipids containing stearic acid at the sn-1 position. After stimulation of the cells with zymosan, both AA and AdA are released in large quantities, albeit AA is released to a greater extent. Finally, a variety of phosphatidylcholine and phosphatidylinositol molecular species contribute to AA; however, AdA is liberated exclusively from phosphatidylcholine species. Collectively, these results identify significant differences in the cellular utilization of AA and AdA by the macrophages, suggesting non-redundant biological actions for these two fatty acids. Copyright © 2012 Elsevier B.V. All rights reserved.

Role of lipoxygenase metabolites of arachidonic acid in enhanced pulmonary artery contractions of female rabbits.

Science.gov (United States)

Pfister, Sandra L

2011-04-01

Pulmonary arterial hypertension is characterized by elevated pulmonary artery pressure and vascular resistance. In women the incidence is 4-fold greater than that in men. Studies suggest that sustained vasoconstriction is a factor in increased vascular resistance. Possible vasoconstrictor mediators include arachidonic acid-derived lipoxygenase (LO) metabolites. Our studies in rabbits showed enhanced endothelium-dependent contractions to arachidonic acid in pulmonary arteries from females compared with males. Because treatment with a nonspecific LO inhibitor reduced contractions in females but not males, the present study identified which LO isoform contributes to sex-specific pulmonary artery vasoconstriction. The 15- and 5- but not 12-LO protein expressions were greater in females. Basal and A23187-stimulated release of 15-, 5-, and 12-hydroxyeicosatetraenoic acids (HETEs) from females and males were measured by liquid chromatography/mass spectrometry. Only 15-HETE synthesis was greater in females compared with males under both basal and stimulated conditions. Vascular contractions to 15-HETE were enhanced in females compared with males (maximal contraction: 44±6%versus 25±3%). The specific 15-LO inhibitor PD146176 (12 μmol/L) decreased arachidonic acid-induced contractions in females (maximal contraction: 93±4% versus 57±10%). If male pulmonary arteries were incubated with estrogen (1 μmol/L, 18 hours), protein expression of 15-LO and 15-HETE production increased. Mechanisms to explain the increased incidence of pulmonary hypertension in women are not known. Results suggest that the 15-LO pathway is different between females and males and is regulated by estrogen. Understanding this novel sex-specific mechanism may provide insight into the increased incidence of pulmonary hypertension in females.

Arachidonic acid metabolism in silica-stimulated bovine alveolar macrophages

International Nuclear Information System (INIS)

Englen, M.D.

1989-01-01

The in vitro production of arachidonic acid (AA) metabolites in adherent bovine alveolar macrophages (BAM) incubated with silica was investigated. BAM were pre-labelled with 3 H-AA, and lipid metabolites released into the culture medium were analyzed by high performance liquid chromatography (HPLC). Lactate dehydrogenase (LDH) release was simultaneously assayed to provide an indication of cell injury. Increasing doses of silica selectively stimulated the 5-lipoxygenase pathway of AA metabolism, while cyclooxygenase metabolite output was suppressed. LDH release increased in a linear, dose-dependent fashion over the range of silica doses used. Moreover, within 15 min following addition of a high silica dose, a shift to the production of 5-lipoxygenase metabolites occurred, accompanied by a reduction in cyclooxygenase products. This rapid alteration in AA metabolism preceded cell injury. To examine the relationship between cytotoxicity and AA metabolite release by BAM exposed to silicas with different cytotoxic and fibrogenic activities, BAM were exposed to different doses of DQ-12, Minusil-5, and Sigma silicas, and carbonyl iron beads. The median effective dose (ED 50 ) of each particulate to stimulate the release of AA metabolites and LDH was calculated. The ED 50 values for DQ-12, Minusil-5, and Sigma silica showed that the relative cytotoxicities of the different silicas for BAM corresponded to the relative potencies of the silicas to elicit 5-lipoxygenase metabolites from BAM. These results indicate that the cytotoxic, and presumed fibrogenic potential, of a silica is correlated with the potency to stimulate the release of leukotrienes from AM

Effects of heparin on platelet aggregation and release and thromboxane A2 production

International Nuclear Information System (INIS)

Mohammad, S.F.; Anderson, W.H.; Smith, J.B.; Chuang, H.Y.; Mason, R.G.

1981-01-01

Heparin, when added to citrated platelet-rich plasma (PRP), caused potentiation of platelet aggregation and the release reaction induced by the aggregating agents adenosine diphosphate (ADP), arachidonic acid, collagen, and epinephrine. At low concentrations (4.7 x 10(-5) M) arachidonic acid failed to cause aggregation of platelets in citrated PRP. However, in the presence of heparin, the same concentration of arachidonic acid caused aggregation. Examination of PRP for the presence of thromboxane A2 (TxA2) by use of a bioassay revealed that heparin also stimulated release of TxA2. This finding indicated that platelets released more TxA2 when they were challenged by low concentrations of arachidonic acid in the presence of heparin than in its absence. Platelets were labeled with 3 H-arachidonic acid and 14 C-serotonin, and attempts were made to determine whether heparin stimulated the platelet release reaction first with subsequent increased production of TxA2, or alternatively, whether heparin stimulated TxA2 production first with subsequent enhancement of the release reaction. In view of the demonstrated simultaneous release of 14 C-serotonin and 3 H-arachidonic acid metabolites, it appeared that either release of 14 C and 3 H occurs concurrently or, even if one of these events is dependent on the other, both events take place in rapid succession. Timed sequential studies revealed that in the presence of arachidonic acid, the addition of heparin hastened the apparently simultaneous release of both 14 C and 3 H

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.

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.

Is arachidonic acid an endoschistosomicide?

Directory of Open Access Journals (Sweden)

Violette Said Hanna

2018-05-01

Full Text Available Schistosoma mansoni and Schistosoma haematobium are intravascular, parasitic flatworms that infect >250 million people in 70 developing countries, yet not all people of the same community and household are afflicted. Regarding laboratory rodents, mice but not rats are susceptible to infection with S. mansoni and hamsters but not mice are entirely permissive to infection with S. haematobium. A recent Brazilian publication has demonstrated that resistance of the water-rat, Nectomys squamipes to S. mansoni infection might be ascribed to stores of arachidonic acid (ARA-rich lipids in liver. Several reports have previously shown that ARA is a safe and effective schistosomicide in vitro, and in vivo in mice, hamsters and in children. Schistosoma haematobium appeared more sensitive than S. mansoni to ARA in in vitro and in vivo experiments. Accordingly, it was proposed that ARA increased levels might be predominantly responsible for natural attrition of S. mansoni and S. haematobium in resistant experimental rodents. Therefore, the levels of ARA in serum, lung, and liver of rats (resistant and mice (susceptible at 1, 2, 3, 4 and 6 weeks after infection with S. mansoni cercariae and between mice (semi-permissive and hamster (susceptible at 1, 2, 3, 4, and 12 weeks after infection with S. haematobium cercariae were compared and contrasted. Neutral triglycerides and ARA levels were assessed in serum using commercially available assays and in liver and lung sections by transmission electron microscopy, Oil Red O staining, and specific anti-ARA antibody-based immunohistochemistry assays. Significant (P < .05, consistent, and reproducible correlation was recorded between ARA content in serum, lung, and liver and rodent resistance to schistosome infection, thereby implicating ARA as an endoschistosomicide. Keywords: Schistosoma mansoni, Schistosoma haematobium, Rat schistosomiasis, Arachidonic acid, Oil Red O staining, Immunohistochemistry

Role of Lipoxygenase Metabolites of Arachidonic Acid in Enhanced Pulmonary Artery Contractions of Female Rabbits

OpenAIRE

Pfister, Sandra L.

2011-01-01

Pulmonary arterial hypertension is characterized by elevated pulmonary artery pressure and vascular resistance. In women the incidence is 4 fold greater than that in men. Studies suggest sustained vasoconstriction is a factor in increased vascular resistance. Possible vasoconstrictor mediators include arachidonic acid-derived lipoxygenase metabolites. Our studies in rabbits showed enhanced endothelium-dependent contractions to arachidonic acid in pulmonary arteries from females compared to ma...

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

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

Study of Arachidonic Acid Pathway in Human Bladder Tumor

Directory of Open Access Journals (Sweden)

Masahide Matsuyama

2009-12-01

Full Text Available 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 tumorigenesis 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 tumorigenesis. 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 tumorigenesis. 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 bladder tumor tissues as well as the effects of COX-2 and LOX inhibitors and PPAR-γ ligand.

Study of Arachidonic Acid Pathway in Human Bladder Tumor

Directory of Open Access Journals (Sweden)

Masahide Matsuyama

2009-01-01

Full Text Available 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 tumorigenesis 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 tumorigenesis. 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 tumorigenesis. 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 bladder tumor tissues as well as the effects of COX-2 and LOX inhibitors and PPAR-γ ligand.

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

International Nuclear Information System (INIS)

Gray, P.R.; Derksen, F.J.; Robinson, N.E.; Peter-Golden, M.L.

1990-01-01

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 (≤12 x 1.5 cm) of pseudostratified columnar epithelium attached to a layer of elastic tissue 30-100 μm thick. Epithelial strips (1.2 x 0.5 cm) were attached to plexiglass rods and incubated with [ 3 H]arachidonic acid in M199 medium (0.5 μCi/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 μM calcium ionophore A23187. The extracted supernatant was processed using HPLC, resulting in peaks of radioactivity that co-eluted with authentic PGE 2 , PGF 2 α, and 12-HETE standards. The greatest activity corresponded to the PGE 2 and PGF 2 α standards, which is a similar pattern to that reported for cultured human tracheal epithelium

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

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......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...

Carbon monoxide is not responsible for the cigarette smokeinduced changes in the pulmonary metabolism of arachidonic acid and prostaglandin E2

International Nuclear Information System (INIS)

Maennistoe, J.; Puustinen, T.; Uotila, P.

1985-01-01

Cigarette smoke is known to interfere with the pulmonary metabolism of arachidomic acid and prostaglandin E 2 (PGE 2 ). We investigated the possible role of carbon monoxide in these cigarette smoke-infuced alterations. 4 C-Arachidonic acid (50 nmol) was indused into the pulmonary circulation of isolated perfused hamster lungs and the radioactive metabolites in the perfusion effluent, as well as the distribution of incorporated radioactive arachidonic acid within the lung lipids, were analysed. Carbon monoxide, added into the ventilatory air, had no effect on the oxidative metabolism of arachidonic acid or on the distribution of radioactive arachidonic acid within the lung. In addition, carbon monoxide had no effect on the metabolism of PGE 2 following infusion of 100 nmol of 14 C-PGE 2 into the rat pulmonary circulation. The present study suggests that carbon monoxide is not responsible for the cigarette smoke-induced changes in the pulmonary metabolism of arachidonic acid and PGE 2 . (author)

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

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

NARCIS (Netherlands)

Anholt, R.D. van; Spanings, F.A.T.; Koven, WM; 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

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.

Enhancement of arachidonic acid signaling pathway by nicotinic acid receptor HM74A

International Nuclear Information System (INIS)

Tang, Yuting; Zhou, Lubing; Gunnet, Joseph W.; Wines, Pamela G.; Cryan, Ellen V.; Demarest, Keith T.

2006-01-01

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

Enhancement of arachidonic acid signaling pathway by nicotinic acid receptor HM74A

Energy Technology Data Exchange (ETDEWEB)

Tang, Yuting [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Zhou, Lubing [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Gunnet, Joseph W [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Wines, Pamela G [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Cryan, Ellen V [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Demarest, Keith T [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States)

2006-06-23

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

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,

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

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....... 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...

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

International Nuclear Information System (INIS)

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

2009-01-01

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

A novel dioxygenation product of arachidonic acid possesses potent chemotactic activity for human polymorphonuclear leukocytes.

Science.gov (United States)

Shak, S; Perez, H D; Goldstein, I M

1983-12-25

We have found that a novel dioxygenation product of arachidonic acid, 8(S),15(S)-dihydroxy-5,11-cis-9,13-trans-eicosatetraenoic acid (8,15-diHETE), possesses chemotactic activity for human polymorphonuclear leukocytes comparable to that of leukotriene B4. Authentic 8,15-diHETE, identified by gas chromatography-mass spectrometry, was prepared by treating arachidonic acid with soybean lipoxygenase and was purified by reverse-phase high performance liquid chromatography. Using a "leading front" assay, 8,15-diHETE exhibited significant chemotactic activity at a concentration of 5.0 ng/ml. Maximum chemotactic activity was observed at a concentration of 30 ng/ml. The 8,15-diHETE generated by mixed human leukocytes after stimulation with arachidonic acid and the calcium ionophore, A23187, exhibited quantitatively similar chemotactic activity. Two synthetic all-trans conjugated isomers of 8,15-diHETE, however, were not chemotactic at concentrations up to 500 ng/ml. In contrast to its potent chemotactic activity, 8,15-diHETE (at concentrations up to 10 micrograms/ml) was relatively inactive with respect to its ability to provoke either degranulation or generation of superoxide anion radicals by cytochalasin B-treated leukocytes. Both leukotriene B4 and 8,15-diHETE may be important mediators of inflammation.

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

International Nuclear Information System (INIS)

Uotila, P.; Puustinen, T.

1985-01-01

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

Arachidonic acid metabolites in normal and autoimmune mice do not influence lymphocyte-high endothelial venule interactions.

Science.gov (United States)

Manolios, N; Bakiera, B; Geczy, C L; Schrieber, L

1991-02-01

In peripheral lymphoid organs the number of lymphocytes and the proportion of functional lymphocyte subsets are regulated by multiple factors including the control of lymphocyte migration by selective lymphocyte-high endothelial venule (HEV) interactions. In this study, prostaglandin E2 (PGE2) levels from normal and autoimmune mouse lymph node cells were measured. The contribution of eicosanoids to lymphocyte-HEV interactions in normal (CBA/T6) and autoimmune (MRL/n) mice was examined. There was no association between PGE2 production in normal or autoimmune mice and the age of onset of disease activity in the latter strains. Arachidonic acid metabolites, in particular PGE2 and leukotriene B4 (LTB4), did not have any effects on lymphocyte-HEV binding. Likewise, lymphocytes treated in vivo and/or in vitro with arachidonic acid metabolite inhibitors (acetyl salicylic acid, indomethacin, BW755C) did not alter lymphocyte-HEV binding interactions in both normal and autoimmune mice. No clinical significance could be attributed to lymph node PGE2 production and the age of onset of autoimmune disease. In summary, these findings cast doubt on the role of arachidonic acid metabolites in lymphocyte-HEV binding interactions.

Relative turnover of [3H]arachidonic acid and [14C]eicosapentaenoic acid in stimulated human platelets

International Nuclear Information System (INIS)

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

1986-01-01

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

Docosahexaenoic acid affects arachidonic acid uptake in megakaryocytes

International Nuclear Information System (INIS)

Schick, P.K.; Webster, P.

1987-01-01

Dietary omega 3 fatty acids are thought to prevent atherosclerosis, possibly by modifying platelet (PT) function and arachidonic acid (20:4) metabolism. The study was designed to determine whether omega 3 fatty acids primarily affect 20:4 metabolism in megakaryocytes (MK), bone marrow precursors of PT, rather than in circulating PT. MK and PT were isolated from guinea pigs and incubated with [ 14 C]-20:4 (0.13uM). Docosahexaenoic acid (22:6) is a major omega 3 fatty acid in marine oils. The incubation of MK with 22:6 (0.1, 1.0 uM) resulted in the decrease of incorporation of [ 14 C]-20:4 into total MK phospholipids, 16% and 41% respectively. Alpha-linolenic acid (18:3), a major omega 3 fatty acid present in American diets, had no effect on 20:4 uptake in MK. 22:6 primarily affected the uptake of [ 14 C]-20:4 into phosphatidylethanolamine (PE) and phosphatidylserine (PS) in MK. In MK, 22:6 (0.1, 1.0 uM) caused a decrease of incorporation of [ 14 C]-20:4 into PE, 21% and 55% respectively; a decrease into PS, 16% and 48% respectively; but only a decrease of 4% and 18%, respectively, into phosphatidylcholine; and a decrease of 3% and 21% into phosphatidylinositol 22:6 (3.0 uM) had no effect on the uptake of AA into PT phospholipids. The study shows that 22:6 has a selective effect on AA uptake in MK and that the acylation or transacylation of PE and PS are primarily affected. 22:6 and other marine omega 3 fatty acids appear to primarily affect megakaryocytes which may result in the production of platelets with abnormal content and compartmentalization of AA

Chronic cigarette smoke exposure adversely alters 14C-arachidonic acid metabolism in rat lungs, aortas and platelets

International Nuclear Information System (INIS)

Lubawy, W.C.; Valentovic, M.A.; Atkinson, J.E.; Gairola, G.C.

1983-01-01

Male rats were exposed to freshly generated cigarette smoke once daily, 5 times a week for 10 weeks. Inhalation of smoke was verified by elevated carboxyhemoglobin in blood sampled immediately after smoke exposure and by increased lung aryl hydrocarbon hydroxylase activity 24 hours after the last smoke exposure. Aortic rings isolated from smoke-exposed rats synthesized less prostacyclin (PGI2) from 14 C-arachidonic acid than rings from sham rats. Platelets from smoke-exposed rats synthesized more thromboxane (TXA2) from 14 C-arachidonic acid than platelets from room controls but not those from sham rats. Lung microsomes from smoke-exposed rats synthesized more TXA2 and had a lower PGI2/TXA2 ratio than lung microsomes from room controls and shams. It is concluded that chronic cigarette smoke exposure alters arachidonic acid metabolism in aortas, platelets and lungs in a manner resulting in decreased PGI2 and increased TXA2, thereby creating a condition favoring platelet aggregation and a variety of cardiovascular diseases

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

The lipid mediators generated by phospholipases A(2) (PLA(2)), free arachidonic acid (AA), eicosanoids, and platelet-activating factor, modulate neuronal activity; when overproduced, some of them become potent neurotoxins. We have shown, using primary cortical neuron cultures, that glutamate...... 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......) and in minor changes in other phospholipids. A similar profile, although of greater magnitude, was observed 20 hr posttreatment. Glutamate (80 microM) induced much less mobilization of (3)H-AA than did sPLA(2) and resulted in a threefold greater degradation of (3)H-AA PE than of (3)H-AA PC by 20 hr...

Inhibitors of the 5-lipoxygenase arachidonic acid pathway induce ATP release and ATP-dependent organic cation transport in macrophages.

Science.gov (United States)

da Silva-Souza, Hercules Antônio; Lira, Maria Nathalia de; Costa-Junior, Helio Miranda; da Cruz, Cristiane Monteiro; Vasconcellos, Jorge Silvio Silva; Mendes, Anderson Nogueira; Pimenta-Reis, Gabriela; Alvarez, Cora Lilia; Faccioli, Lucia Helena; Serezani, Carlos Henrique; Schachter, Julieta; Persechini, Pedro Muanis

2014-07-01

We have previously described that arachidonic acid (AA)-5-lipoxygenase (5-LO) metabolism inhibitors such as NDGA and MK886, inhibit cell death by apoptosis, but not by necrosis, induced by extracellular ATP (ATPe) binding to P2X7 receptors in macrophages. ATPe binding to P2X7 also induces large cationic and anionic organic molecules uptake in these cells, a process that involves at least two distinct transport mechanisms: one for cations and another for anions. Here we show that inhibitors of the AA-5-LO pathway do not inhibit P2X7 receptors, as judged by the maintenance of the ATPe-induced uptake of fluorescent anionic dyes. In addition, we describe two new transport phenomena induced by these inhibitors in macrophages: a cation-selective uptake of fluorescent dyes and the release of ATP. The cation uptake requires secreted ATPe, but, differently from the P2X7/ATPe-induced phenomena, it is also present in macrophages derived from mice deficient in the P2X7 gene. Inhibitors of phospholipase A2 and of the AA-cyclooxygenase pathway did not induce the cation uptake. The uptake of non-organic cations was investigated by measuring the free intracellular Ca(2+) concentration ([Ca(2+)]i) by Fura-2 fluorescence. NDGA, but not MK886, induced an increase in [Ca(2+)]i. Chelating Ca(2+) ions in the extracellular medium suppressed the intracellular Ca(2+) signal without interfering in the uptake of cationic dyes. We conclude that inhibitors of the AA-5-LO pathway do not block P2X7 receptors, trigger the release of ATP, and induce an ATP-dependent uptake of organic cations by a Ca(2+)- and P2X7-independent transport mechanism in macrophages. Copyright © 2014 Elsevier B.V. All rights reserved.

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

Science.gov (United States)

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

2015-01-01

Symptoms of cardiovascular diseases are frequently found in patients with hypothyroidism and hyperthyroidism. However, it is unknown whether arachidonic acid metabolites, the potent mediators in cardiovascular system, are involved in cardiovascular disorders caused by hyperthyroidism and hypothyroidism. To answer this question, serum levels of arachidonic acid metabolites in human subjects with hypothyroidism, hyperthyroidism and mice with hypothyroidism or thyroid hormone treatment were determined by a mass spectrometry-based method. Over ten arachidonic acid metabolites belonging to three catalytic pathways: cyclooxygenases, lipoxygenases, and cytochrome P450, were quantified simultaneously and displayed characteristic profiles under different thyroid hormone status. The level of 20-hydroxyeicosatetraenoic acid, a cytochrome P450 metabolite, was positively correlated with thyroid hormone level and possibly contributed to the elevated blood pressured in hyperthyroidism. The increased prostanoid (PG) I2 and decreased PGE2 levels in hypothyroid patients might serve to alleviate atherosclerosis associated with dyslipidemia. The elevated level of thromboxane (TX) A2, as indicated by TXB2, in hyperthyroid patients and mice treated with thyroid hormone might bring about pulmonary hypertension frequently found in hyperthyroid patients. In conclusion, our prospective study revealed that arachidonic acid metabolites were differentially affected by thyroid hormone status. Certain metabolites may be involved in cardiovascular disorders associated with thyroid diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

Arachidonic acid production by the oleaginous fungus Mortierella alpina 1S-4: A review

Directory of Open Access Journals (Sweden)

Hiroshi Kikukawa

2018-05-01

Full Text Available The filamentous fungus Mortierella alpina 1S-4 is capable of accumulating a large amount of triacylglycerol containing C20 polyunsaturated fatty acids (PUFAs. Indeed, triacylglycerol production by M. alpina 1S-4 can reach 20 g/L of culture broth, and the critical cellular signaling and structural PUFA arachidonic acid (ARA comprises 30%–70% of the total fatty acid. The demonstrated health benefits of functional PUFAs have in turn encouraged the search for rich sources of these compounds, including fungal strains showing enhanced production of specific PUFAs. Screening for mutants and targeted gene manipulation of M. alpina 1S-4 have elucidated the functions of various enzymes involved in PUFA biosynthesis and established lines with improved PUFA productivity. In some cases, these strains have been used for indistrial-scale production of PUFAs, including ARA. In this review, we described practical ARA production through mutant breeding, functional analyses of genes encoding enzymes involved in PUFA biosynthesis, and recent advances in the production of specific PUFAs through molecular breeding of M. alpina 1S-4. Keywords: Arachidonic acid, Mortierella alpina, Molecular breeding, Fatty acid desaturase

Novel metabolic pathways for linoleic and arachidonic acid metabolism.

Science.gov (United States)

Moghaddam, M; Motoba, K; Borhan, B; Pinot, F; Hammock, B D

1996-08-13

Mouse liver microsomes oxidized linoleic acid to form 9,10- or 12,13-epoxyoctadecenoate. These monoepoxides were subsequently hydrolyzed to their corresponding diols in the absence of the microsomal epoxide hydrolase inhibitor, 1,2-epoxy-3,3,3-trichloropropane. Furthermore, both 9,10- and 12,13-epoxyoctadecenoates were oxidized to diepoxyoctadecanoate at apparently identical rates by mouse liver microsomal P-450 epoxidation. Both epoxyoctadecanoates and diepoxyoctadecanoates were converted to tetrahydrofuran-diols by microsomes. Tetrahydroxides of linoleate were produced as minor metabolites. Arachidonic acid was metabolized to epoxyeicosatrienoates, dihydroxyeicosatrienoates, and monohydroxyeicosatetraenoates by the microsomes. Microsomes prepared from clofibrate (but not phenobarbital) -treated mice exhibited much higher production rates for epoxyeicosatrienoates and vic-dihydroxyeicosatrienoates. This indicated an induction of P-450 epoxygenase(s) and microsomal epoxide hydrolase in mice by clofibrate and not by phenobarbital. Incubation of synthetic epoxyeicosatrienoates with microsomes led to the production of diepoxyeicosadienoates. Among chemically generated diepoxyeicosadienoate isomers, three of them possessing adjacent diepoxides were hydrolyzed to their diol epoxides which cyclized to the corresponding tetrahydrofuran-diols by microsomes as well as soluble epoxide hydrolase at a much higher rate. Larger cyclic products from non-adjacent diepoxides were not observed. The results of our in vitro experiments suggest that linoleic and arachidonic acid can be metabolized to their tetrahydrofuran-diols by two consecutive microsomal cytochrome P-450 epoxidations followed by microsomal or soluble epoxide hydrolase catalyzed hydrolysis of the epoxides. Incubation experiments with the S-9 fractions indicate that the soluble epoxide hydrolase is more important in this conversion. This manuscript is the first report of techniques for the separation and

The effect of cigarette smoke on the metabolism of arachidonic acid in isolated hamster lungs

International Nuclear Information System (INIS)

Maennistoe, J.; Toivonen, H.; Hartiala, J.; Bakhle, Y.S.; Uotila, P.

1981-01-01

The effects of cigarette smoke on the metabolism of exogenous arachidonic acid (AA) were investigated in isolated hamster lungs. Arachidonate was injected into the pulmonary circulation and the metabolites were analysed from the nonrecirculating perfusion effluent by thin layer chromatography. After the pulmonary injection of 66 nmol of 14C-AA about 20% of the injected radioactivity appeared in the perfusion effluent mostly as metabolites in six minutes. When isolated lungs were ventilated with cigarette smoke during the perfusion, the amounts of PGF2 alpha, PGE2 and two unidentified metabolite groups increased in the lung effluent. In two other experimental series hamsters were exposed to cigarette smoke before the lung perfusion either once for 30 min or during one hour daily for ten consecutive days. Neither pre-exposures caused any changes in the amounts of arachidonate metabolites in the lung effluent

Arachidonic acid metabolism in fibroblasts derived from canine myocardium

International Nuclear Information System (INIS)

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

1986-01-01

Canine fibroblasts from normal or healing infarcted myocardium were grown in culture. The cells were morphologically indistinguishable, but the doubling time of cells from healing myocardium was 39.6 +/- 3.5 hr whereas that of normals was 24 +/- 3.7 (n=5, p 3 H]arachidonate (AA) into phospholipids. Calcium ionophore A23187 (10 μM) caused release and metabolism of [ 3 H] AA. A23187 or AA (10μM) induced production of 6-keto PGF1α, PGE2, and a hydroxy metabolite of AA. RIA of 6-keto PGF1α showed that subconfluent cells from healing myocardium produced 1202 +/- 354 pg/mg protein whereas that of normals was 551 +/- 222 (n=7, p 3 H]AA released but did not metabolize [ 3 H]AA. In coincubations, fibroblasts incorporated myocyte-derived AA. Subsequent stimulation of the fibroblasts with A23187 induced the synthesis of 6-keto PGF1α, PGE2 and a hydroxy metabolite. The fibroblast content of healing myocardium was 35-1000 times that of normal tissue (n=7). Thus even a moderate change in AA metabolism, amplified by the AA released from deteriorating myocytes, may be a significant physiologic or pathologic event

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

Effect of oxygen deprivation on metabolism of arachidonic acid by cultures of rat heart cells

International Nuclear Information System (INIS)

Freyss-Beguin, M.; Millanvoye-van Brussel, E.; Duval, D.

1989-01-01

To investigate the mechanisms responsible for the impairment of phospholipid metabolism observed in ischemic cells, we have studied the effect of conditions simulating ischemia on the metabolism of arachidonic acid (AA) by muscle (M-) and nonmuscle (F-) cells isolated from newborn rat hearts and cultured separately. In muscle cells, oxygen deprivation induces a significant stimulation of the release of [ 14 C]AA from prelabeled cells associated with a preferential redistribution of [ 14 C]AA into cell triglycerides but not formation of radioactive prostaglandins. Moreover, the fatty acid content of phospholipids, as measured by capillary gas chromatography, appears markedly reduced in ischemic myocardial cells. This fact may be related to phospholipase stimulation during ischemia as suggested by the antagonistic effect of mepacrine or p-bromophenacyl bromide. In contrast, oxygen deprivation failed to induce any significant alteration of AA metabolism in fibroblast-like heart cells. Our results indicate that these cultures of newborn rat heart cells, which exhibit many of the features observed in intact organ during ischemia, may represent a useful experimental model to investigate the pharmacological control of the membrane phospholipid turnover

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

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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

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

mRNA levels of enzymes and receptors implicated in arachidonic acid metabolism in gliomas.

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De Armas, Rafael; Durand, Karine; Guillaudeau, Angélique; Weinbreck, Nicolas; Robert, Sandrine; Moreau, Jean-Jacques; Caire, François; Acosta, Gisela; Pebet, Matias; Chaunavel, Alain; Marin, Benoît; Labrousse, François; Denizot, Yves

2010-07-01

Gliomas are tumors of the central nervous system derived from glial cells. They show cellular heterogeneity and lack specific diagnostic markers. Although a possible role for the eicosanoid cascade has been suggested in glioma tumorigenesis, the relationship between enzymes and receptors implicated in arachidonic acid metabolism, with histological tumor type has not yet been determined. Quantitative real-time reverse transcription-polymerase chain reaction was performed to measure and compare transcript levels of enzymes and receptors implicated in both lipoxygenase and cyclooxygenase pathways between oligodendrogliomas, astrocytomas, glioblastomas and mixed oligoastrocytomas. Arachidonic acid metabolism-related enzymes and receptor transcripts (i) were underexpressed in classical oligodendrogliomas compared to astrocytomas and/or glioblastomas, (ii) differed between astrocytomas and glioblastomas and (iii) had an intermediate expression in mixed oligoastrocytomas. mRNA levels of enzymes and receptors implicated both in lipoxygenase and cyclooxygenase pathways differed significantly in gliomas according to the histological type. Copyright 2010 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Decreased arachidonic acid content and metabolism in tissues of NZB/W F1 females fed a diet containing 0.45% dehydroisoandrosterone (DHA)

International Nuclear Information System (INIS)

Matsunaga, A.; Cottam, G.L.

1987-01-01

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- 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 PGF1α 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

Food Polyphenol Apigenin Inhibits the Cytochrome P450 Monoxygenase Branch of the Arachidonic Acid Cascade.

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Steuck, Maryvonne; Hellhake, Stefan; Schebb, Nils Helge

2016-11-30

The product of cytochrome P450 monooxygenase (P450) ω-hydroxylation of arachidonic acid (AA), 20- hydroxyeicosatetraenoic acid (HETE), is a potent vasoconstrictor. Utilizing microsomes as well as individual CYP4 isoforms we demonstrate here that flavonoids can block 20-HETE formation. Apigenin inhibits CYP4F2 with an IC 50 value of 4.6 μM and 20-HETE formation in human liver and kidney microsomes at 2.4-9.8 μM. Interestingly, the structurally similar naringenin shows no relevant effect on the formation of 20-HETE. Based on these in vitro data, it is impossible to evaluate if a relevant blockade of 20-HETE formation can result in humans from intake of polyphenols with the diet. However, the potency of apigenin is comparable to those of P450 inhibitors such as ketoconazole. Moreover, an IC 50 value in the micromolar range is also described for the inhibition of CYP-mediated drug metabolism leading to food-drug interactions. The modulation of the arachidonic acid cascade by food polyphenols therefore warrants further investigation.

Arachidonic acid metabolites and endothelial dysfunction of portal hypertension.

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Sacerdoti, David; Pesce, Paola; Di Pascoli, Marco; Brocco, Silvia; Cecchetto, Lara; Bolognesi, Massimo

2015-07-01

Increased resistance to portal flow and increased portal inflow due to mesenteric vasodilatation represent the main factors causing portal hypertension in cirrhosis. Endothelial cell dysfunction, defined as an imbalance between the synthesis, release, and effect of endothelial mediators of vascular tone, inflammation, thrombosis, and angiogenesis, plays a major role in the increase of resistance in portal circulation, in the decrease in the mesenteric one, in the development of collateral circulation. Reduced response to vasodilators in liver sinusoids and increased response in the mesenteric arterioles, and, viceversa, increased response to vasoconstrictors in the portal-sinusoidal circulation and decreased response in the mesenteric arterioles are also relevant to the pathophysiology of portal hypertension. Arachidonic acid (AA) metabolites through the three pathways, cyclooxygenase (COX), lipoxygenase, and cytochrome P450 monooxygenase and epoxygenase, are involved in endothelial dysfunction of portal hypertension. Increased thromboxane-A2 production by liver sinusoidal endothelial cells (LSECs) via increased COX-1 activity/expression, increased leukotriens, increased epoxyeicosatrienoic acids (EETs) (dilators of the peripheral arterial circulation, but vasoconstrictors of the portal-sinusoidal circulation), represent a major component in the increased portal resistance, in the decreased portal response to vasodilators and in the hyper-response to vasoconstrictors. Increased prostacyclin (PGI2) via COX-1 and COX-2 overexpression, and increased EETs/heme-oxygenase-1/K channels/gap junctions (endothelial derived hyperpolarizing factor system) play a major role in mesenteric vasodilatation, hyporeactivity to vasoconstrictors, and hyper-response to vasodilators. EETs, mediators of liver regeneration after hepatectomy and of angiogenesis, may play a role in the development of regenerative nodules and collateral circulation, through stimulation of vascular endothelial

Prostaglandin release from in vitro guinea-pig gallbladder.

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Booker, M L; LaMorte, W W

1983-02-01

In order to study prostaglandin release from guinea pig gallbladder, full thickness tissue sections were incubated for one hour in Krebs solution. Extraction and two dimensional chromatography of incubation media obtained in the presence of radio-labelled arachidonic acid demonstrated the presence of PGE2, PGF2 alpha, 6-keto-PGF1 alpha and thromboxane B2. These results were supported by radioimmunoassay of incubations conducted in the absence of exogenous arachidonate and in the presence of varying concentrations of unlabelled exogenous arachidonate. The previously reported predominance of PGE2 was only seen at high concentrations of exogenous arachidonate.

Acrolein stimulates eicosanoid release from bovine airway epithelial cells

International Nuclear Information System (INIS)

Doupnik, C.A.; Leikauf, G.D.

1990-01-01

Injury to the airway mucosa after exposure to environmental irritants is associated with pulmonary inflammation and bronchial hyperresponsiveness. To better understand the relationships between mediator release and airway epithelial cell injury during irritant exposures, we studied the effects of acrolein, a low-molecular-weight aldehyde found in cigarette smoke, on arachidonic acid metabolism in cultured bovine tracheal epithelial cells. Confluent airway epithelial cell monolayers, prelabeled with [3H]arachidonic acid, released significant levels of 3H activity when exposed (20 min) to 100 microM acrolein. [3H]arachidonic acid products were resolved using reverse-phase high-performance liquid chromatography. Under control conditions the released 3H activity coeluted predominantly with the cyclooxygenase product, prostaglandin (PG) E2. After exposure to acrolein, significant peaks in 3H activity coeluted with the lipoxygenase products 12-hydroxyeicosatetraenoic acid (HETE) and 15-HETE, as well as with PGE2, PGF2 alpha, and 6-keto-PGF1 alpha. Dose-response relationships for acrolein-induced release of immunoreactive PGF2 alpha and PGE2 from unlabeled epithelial monolayers demonstrated 30 microM acrolein as the threshold dose, with 100 microM acrolein inducing nearly a fivefold increase in both PGF2 alpha and PGE2. Cellular viability after exposure to 100 microM acrolein, determined by released lactate dehydrogenase activity, was not affected until exposure periods were greater than or equal to 2 h. These results implicate the airway epithelial cell as a possible source of eicosanoids after exposure to acrolein

Effects of different arachidonic acid supplementation on psychomotor development in very preterm infants; a randomized controlled trial.

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Alshweki, Ayham; Muñuzuri, Alejandro Pérez; Baña, Ana M; de Castro, Ma José; Andrade, Fernando; Aldamiz-Echevarría, Luís; de Pipaón, Miguel Sáenz; Fraga, José M; Couce, María L

2015-09-30

Nutritional supplementation with polyunsaturated fatty acids is important in preterm infants neurodevelopment, but it is not known if the omega-6/omega-3 ratio affects this process. This study was designed to determine the effects of a balanced contribution of arachidonic acid in very preterm newborns fed with formula milk. This was a randomized trial, in which newborns psychomotor development was assessed using the Brunet Lézine scale at 24 months corrected age. A control group, for comparison of Brunet Lézine score, was made up of 25 newborns from the SEN1500 project, who were fed exclusively with breast milk. At 12 months, arachidonic acid values were significantly higher in group A than in group B (6.95 ± 1.55% vs. 4.55 ± 0.78%), as were polyunsaturated fatty acids (41.02 ± 2.09% vs. 38.08 ± 2.32%) achieved a higher average. Group A achieved a higher average Brunet Lézine score at 24 months than group B (99.9 ± 9 vs. 90.8 ± 11, p =0.028). The Brunet Lézine results from group A were compared with the control group results, with very similar scores registered between the two groups (99.9 ± 9 vs. 100.5 ± 7). There were no significant differences in growth or evoked potentials between the two formula groups. Very preterm infants who received formula with an ω-6/ω-3 ratio of 2/1 had higher blood levels of essential fatty acids during the first year of life, and better psychomotor development, compared with very preterm newborns who consumed formula with an ω-6/ω-3 of 1/1. Therefore, formula milk with an arachidonic acid quantity double that of docosahexaenoic acid should be considered for feeding very preterm infants. ClinicalTrials.gov Identifier NCT02503020.

Arachidonic acid/docosahexaenoic acid-supplemented diet in early life reduces body weight gain, plasma lipids, and adiposity in later life in ApoE*3 Leiden mice

NARCIS (Netherlands)

Wielinga, P.Y.; Harthoorn, L.F.; Verschuren, L.; Schoemaker, M.H.; Jouni, Z.E.; Tol, E.A.F. van; Kleemann, R.; Kooistra, T.

2012-01-01

Scope: This study addresses whether early life arachidonic acid (ARA)/docosahexaenoic acid (DHA) supplementation or eicosapentaenoic acid (EPA)/DHA (Omacor) supplementation affects body weight gain, lipid metabolism, and adipose tissue quantity and quality in later life in ApoE*3Leiden-transgenic

Arachidonic acid and other unsaturated fatty acids and some of their metabolites function as endogenous antimicrobial molecules: A review

Directory of Open Access Journals (Sweden)

Undurti N. Das

2018-05-01

Full Text Available Our body is endowed with several endogenous anti-microbial compounds such as interferon, cytokines, free radicals, etc. However, little attention has been paid to the possibility that lipids could function as antimicrobial compounds. In this short review, the antimicrobial actions of various polyunsaturated fatty acids (PUFAs, mainly free acids and their putative mechanisms of action are described. In general, PUFAs kill microbes by their direct action on microbial cell membranes, enhancing generation of free radicals, augmenting the formation of lipid peroxides that are cytotoxic, and by increasing the formation of their bioactive metabolites, such as prostaglandins, lipoxins, resolvins, protectins and maresins that enhance the phagocytic action of leukocytes and macrophages. Higher intakes of α-linolenic and cis-linoleic acids (ALA and LA respectively and fish (a rich source of eicosapentaenoic acid and docosahexaenoic acid might reduce the risk pneumonia. Previously, it was suggested that polyunsaturated fatty acids (PUFAs: linoleic, α-linolenic, γ-linolenic (GLA, dihomo-GLA (DGLA, arachidonic (AA, eicosapentaenoic (EPA, and docosahexaenoic acids (DHA function as endogenous anti-bacterial, anti-fungal, anti-viral, anti-parasitic, and immunomodulating agents. A variety of bacteria are sensitive to the growth inhibitory actions of LA and ALA in vitro. Hydrolyzed linseed oil can kill methicillin-resistant Staphylococcus aureus. Both LA and AA have the ability to inactivate herpes, influenza, Sendai, and Sindbis virus within minutes of contact. AA, EPA, and DHA induce death of Plasmodium falciparum both in vitro and in vivo. Prostaglandin E1 (PGE1 and prostaglandin A (PGA, derived from DGLA, AA, and EPA inhibit viral replication and show anti-viral activity. Oral mucosa, epidermal cells, lymphocytes and macrophages contain and release significant amounts of PUFAs on stimulation. PUFAs stimulate NADPH-dependent superoxide production by

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

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

2000-12-01

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

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

International Nuclear Information System (INIS)

Schlesinger, R.B.; Driscoll, K.E.; Gunnison, A.F.; Zelikoff, J.T.

1990-01-01

Ozone (O 3 ) and nitrogen dioxide (NO 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 3 at 0.1, 0.3, or 1 ppm; NO 2 at 1, 3, or 10 ppm; or to a mixture of 0.3 ppm O 3 and 3 ppm NO 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 3 . Exposure to 10 ppm NO 2 resulted in a depression of 6-keto-PGF1 alpha, while thromboxane B2 (TxB2) was elevated after exposure to 1 ppm NO 2 and depressed following 3 and 10 ppm. The O 3 /NO 2 mixture resulted in synergistic increases in PGE2 and PGF2 alpha, with the response appearing to be driven by O 3 . This study has demonstrated that acute exposure to either O 3 or NO 2 can alter pulmonary arachidonic acid metabolism and that the responses to these oxidants differ, both quantitatively and qualitatively

12(R)-hydroxyicosatetraenoic acid: a cytochrome P450-dependent arachidonate metabolite that inhibits Na+, K+-ATPase in the cornea

International Nuclear Information System (INIS)

Schwartzman, M.L.; Balazy, M.; Masferrer, J.; Abraham, N.G.; McGiff, J.C.; Murphy, R.C.

1987-01-01

When corneal microsomes were incubated with arachidonic acid in the presence of an NADPH-generating system, four polar metabolites (compounds A-D) were formed. Synthesis of these metabolites could be inhibited by carbon monoxide, SKF 525A, and anti-cytochrome c reductase antibodies. One of the metabolites, compound C, was found to inhibit partially purified Na + , K + -ATPase from the corneal epithelium in a dose-dependent manner. After compound C was purified by TLC and HPLC, it was found to have a UV absorption spectrum with a maximum absorbance at 236 nm suggesting the presence of a conjugated diene. Mass spectrometric analysis using positive- and negative-ionization modes was carried out on derivatized compound C. Abundant fragment ions were consistent with compound C being a monooxygenated derivative of arachidonic acid with a hydroxyl substituent at carbon-12 of the icosanoid backbone; all deuterium atoms from [ 2 H 8 ]arachidonate were retained in the structure. Compound C was characterized as a 12-hydroxyicosatetraenoic acid. However, only 12(R) isomer was found to be an inhibitor of the Na + , K + -ATPase from the corneal epithelium, suggesting that the biologically active compound C was 12(R)-hydroxyy-5,8,10,14-icosatetraenoic acid. Such an inhibitor of Na + , K + -ATPase synthesized in the cornea may have an important role in regulating ocular transparency and aqueous human secretion

Clinical implications of eicosapentaenoic acid/arachidonic acid ratio (EPA/AA) in adult patients with congenital heart disease.

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Kanoh, Miki; Inai, Kei; Shinohara, Tokuko; Tomimatsu, Hirofumi; Nakanishi, Toshio

2017-12-01

Recent studies showed that a low ratio between the levels of eicosapentaenoic acid and those of arachidonic acid (EPA/AA) is associated with higher incidence of coronary artery disease and poor prognosis of heart failure, arrhythmia, and cardiac sudden death. However, the clinical implications of EPA/AA in adult patients with congenital heart disease remain unclear. We aimed to assess the prognostic value of EPA/AA regarding cardiac events in adult patients with congenital heart disease. We measured the serum levels of eicosapentaenoic acid and arachidonic acid in 130 adult patients (median age, 31 years) stratified into two groups according to their EPA/AA (low, ≤0.22; high, >0.22). We prospectively analyzed the association between EPA/AA and incidence of cardiac events during a mean observation period of 15 months, expressed in terms of hazard ratio (HR) with 95% confidence interval (95% CI). In the subgroup of patients with biventricular circulation (2VC) (n = 76), we analyzed the same clinical endpoints. In our study population, EPA/AA was not associated with the incidence of arrhythmic events (HR, 1.52; 95% CI, 0.82-2.85; p = 0.19), but low EPA/AA was a predictor of heart failure hospitalization (HR, 2.83; 95% CI, 1.35-6.30; p AA of ≤0.25 was associated with a significantly higher risk of arrhythmic events (HR, 2.55; 95% CI, 1.11-6.41; p = 0.03) and heart failure hospitalization (HR, 5.20; 95% CI, 1.78-18.1; p AA represents a useful predictor of cardiac events in adult patients with congenital heart disease.

Dietary arachidonic acid in perinatal nutrition: a commentary.

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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.

Hepatic arachidonic acid metabolism is disrupted after hexachlorobenzene treatment

International Nuclear Information System (INIS)

Billi de Catabbi, Silvia C.; Faletti, Alicia; Fuentes, Federico; San Martin de Viale, Leonor C.; Cochon, Adriana C.

2005-01-01

Hexaclorobenzene (HCB), one of the most persistent environmental pollutants, can cause a wide range of toxic effects including cancer in animals, and hepatotoxicity and porphyria both in humans and animals. In the present study, liver microsomal cytochrome P450 (CYP)-dependent arachidonic acid (AA) metabolism, hepatic PGE production, and cytosolic phospholipase A 2 (cPLA 2 ) activity were investigated in an experimental model of porphyria cutanea tarda induced by HCB. Female Wistar rats were treated with a single daily dose of HCB (100 mg kg -1 body weight) for 5 days and were sacrificed 3, 10, 17, and 52 days after the last dose. HCB treatment induced the accumulation of hepatic porhyrins from day 17 and increased the activities of liver ethoxyresorufin O-deethylase (EROD), methoxyresorufin O-demethylase (MROD), and aminopyrine N-demethylase (APND) from day 3 after the last dose. Liver microsomes from control and HCB-treated rats generated, in the presence of NADPH, hydroxyeicosatetraenoic acids (HETEs), epoxyeicosatrienoic acids (EETs), 11,12-Di HETE, and ω-OH/ω-1-OH AA. HCB treatment caused an increase in total NADPH CYP-dependent AA metabolism, with a higher response at 3 days after the last HCB dose than at the other time points studied. In addition, HCB treatment markedly enhanced PGE production and release in liver slices. This HCB effect was time dependent and reached its highest level after 10 days. At this time cPLA 2 activity was shown to be increased. Unexpectedly, HCB produced a significant decrease in cPLA 2 activity on the 17th and 52nd day. Our results demonstrated for the first time that HCB induces both the cyclooxygenase and CYP-dependent AA metabolism. The effects of HCB on AA metabolism were previous to the onset of a marked porphyria and might contribute to different aspects of HCB-induced liver toxicity such as alterations of membrane fluidity and membrane-bound protein function. Observations also suggested that a possible role of cPLA 2 in

Lamotrigine blocks NMDA receptor-initiated arachidonic acid signalling in rat brain: Implications for its efficacy in bipolar disorder

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Ramadan, Epolia; Basselin, Mireille; Rao, Jagadeesh S.; Chang, Lisa; Chen, Mei; Ma, Kaizong; Rapoport, Stanley I.

2011-01-01

An upregulated brain arachidonic acid (AA) cascade and a hyperglutamatergic state characterize bipolar disorder (BD). Lamotrigine (LTG), a mood stabilizer approved for treating BD, is reported to interfere with glutamatergic neurotransmission involving N-methyl-D-aspartate receptors (NMDARs). NMDARs allow extracellular calcium into the cell, thereby stimulating calcium-dependent cytosolic phospholipase A2 (cPLA2) to release arachidonic acid (AA) from membrane phospholipid. We hypothesized that LTG, like other approved mood stabilizers, would reduce NMDAR-mediated AA signaling in rat brain. An acute subconvulsant dose of NMDA (25 mg/kg) or saline was administered intraperitoneally to unanesthetized rats that had been treated p.o. daily for 42 days with vehicle or a therapeutically relevant dose of LTG (10 mg/kg/.d). Regional brain AA incorporation coefficients k* and rates Jin, AA signals, were measured using quantitative autoradiography after intravenous [1-14C]AA infusion, as were other AA cascade markers. In chronic vehicle-treated rats, acute NMDA compared to saline increased k* and Jin in widespread regions of the brain, as well as prostaglandin (PG)E2 and thromboxane B2 concentrations. Chronic LTG treatment compared to vehicle reduced brain cyclooxygenase (COX) activity, PGE2 concentration, and DNA binding activity of the COX-2 transcription factor, NF-κB. Pretreatment with chronic LTG blocked the acute NMDA effects on AA cascade markers. In summary, chronic LTG like other mood stabilizers blocks NMDA-mediated signaling involving the AA metabolic cascade. Since markers of the AA cascade and of NMDAR signaling are up-regulated in the postmortem BD brain, mood stabilizers generally may be effective in BD by dampening NMDAR signalling and the AA cascade. PMID:21733229

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.

Differentiation of U937 cells induced by 5,8,11,14-eicosatetraynoic acid, a competitive inhibitor of arachidonic acid metabolism

International Nuclear Information System (INIS)

Ondrey, F.; Anderson, K.; Hoeltgen, D.; Harris, J.

1988-01-01

5,8,11,14-Eicosatetraynoic acid, a competitive inhibitor of arachidonic acid metabolism, rapidly and reversibly inhibited DNA synthesis in U937 cells. This inhibition was not due to cytotoxicity, as judged by studies with trypan blue, release of 51 Cr-labeled proteins, and its reversibility. When cells were cultured in the presence of ETYA for several days, morphologic, enzymatic, and functional changes consistent with differentiation occurred. The cells enlarged, the ratio of cytoplasm to nuclei increased, secretory granules and vacuoles developed, the apparent activity of nonspecific esterase rose, and ingestion of latex particles increased. A morphology consistent with that of an immature monocyte was evident by electron microscopy. When cells differentiated by ETYA were cultured in media free of the inhibitor, DNA synthesis reinitiated and the cell number increased; differentiation was phenotypic and not genotypic. To examine whether ETYA-induced differentiation was obligatorily related to its suppression of DNA synthesis, cells were incubated in 50 μM hydroxyurea and DNA synthesis was inhibited for 24 to 36 h without morphologic evidence of cellular differentiation. However, addition of ETYA to cells prevented from dividing by hydroxyurea and subsequent culture for 72 h induced morphologic evidence of differentiation. The effects of ETYA on cell division and cell differentiation are closely related but can be dissociated

Identification of rabbit cytochromes P450 2C1 and 2C2 as arachidonic acid epoxygenases.

Science.gov (United States)

Laethem, R M; Koop, D R

1992-12-01

Microsomes prepared from COS-1 cells transiently expressing rabbit cytochromes P450 2C1 and 2C2 catalyzed the metabolism of arachidonic acid to predominantly 11,12- and 14,15-epoxyeicosatrienoic acids (EETs) when microsomal epoxide hydrolase activity was inhibited by 0.2 mM 1,2-epoxy-3,3,3-trichloropropane. P450 2C2 catalyzed the formation of 11,12-EET and 14,15-EET at a ratio of 3.0 and also produced 19-hydroxyeicosatetraenoic acid (19-HETE). The 11,12-EET, 14,15-EET, and 19-HETE represented 48.3, 15.9, and 12.8%, respectively, of the total metabolites formed. P450 2C1 produced a similar but distinct ratio of 11,12-EET to 14,15-EET (2.0) and did not produce any detectable 19-HETE. The 11,12-EET and 14,15-EET represented 63.0 and 31.1%, respectively, of the total metabolites formed. The 8,9- and 5,6-EETs were not detected with either enzyme. The ratio of the 11,12-EET to 14,15-EET was 1.5 with P450 2CAA, a P450 arachidonic acid epoxygenase (P450 2CAA) that had an amino-terminal sequence identical to that of P450 2C2 [J. Biol. Chem. 267:5552-5559 (1992)]. P450 2C1, 2C2, and 2CAA metabolized lauric acid. The ratio of omega-1- to omega-hydroxylated laurate was 3.6, 3.4, and 2.4 for P450 2CAA, P450 2C2, and P450 2C1, respectively. Purified P450 2CAA had a slightly greater apparent molecular weight than expressed P450 2C2 on sodium dodecyl sulfate-polyacrylamide gels. The results clearly establish that rabbit P450 2C1 and 2C2 are arachidonic acid epoxygenases, and they suggest that P450 2CAA and 2C2 are very similar but may not be identical isoforms.

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

Evidence confirms that polyunsaturated fatty acids (PUFAs), arachidonic acid (ARA), eicosapentaenoic acid (EPA) and docosahexaenoic acid, DHA are involved in growth as well in pigmentation of marine fish larvae. In the present study we examined the performance of common sole larvae reared...... on Artemia enriched with 10 formulated emulsions, differing in inclusions of ARA, EPA, and DHA. The specific growth rate of the sole larvae until late metamorphosis, 21 days after hatching (dah) was 20 to 27% d(-1). Even though the relative tissue essential fatty acid (EFA) concentrations significantly...... 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...

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

International Nuclear Information System (INIS)

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

1982-01-01

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

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.

A new model to study the role of arachidonic acid in colon cancer pathophysiology

OpenAIRE

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

2016-01-01

A significant increase in cyclooxygenase 2 (COX2) gene expression has been shown to promote cylcooxygenase-dependent colon cancer development. Controversy associated with the role of COX2 inhibitors indicates that additional work is needed to elucidate the effects of arachidonic acid (AA) derived (cyclooxygenase and lipoxygenase) eicosanoids in cancer initiation, progression and metastasis. We have recently developed a novel Fads1 knockout mouse model, which allows for the investigation of AA...

Arachidonic Acid-Induced Expression of the Organic Solute and Steroid Transporter-beta (Ost-beta) in a Cartilaginous Fish Cell Line

Science.gov (United States)

Hwang, Jae-Ho; Parton, Angela; Czechanski, Anne; Ballatori, Nazzareno; Barnes, David

2008-01-01

The organic solute and steroid transporter (OST/Ost) is a unique membrane transport protein heterodimer composed of subunits designated alpha and beta, that transports conjugated steroids and prostaglandin E2 across the plasma membrane. Ost was first identified in the liver of the cartilaginous fish Leucoraja erinacea, the little skate, and subsequently was found in many other species, including humans and rodents. The present study describes the isolation of a new cell line, LEE-1, derived from an early embryo of L. erinacea, and characterizes the expression of Ost in these cells. The mRNA size and amino acid sequence of Ost-beta in LEE-1 was identical to that previously reported for Ost-beta from skate liver, and the primary structure was identical to that of the spiny dogfish shark (Squalus acanthias) with the exception of a single amino acid. Ost-beta was found both on the plasma membrane and intracellularly in LEE-1 cells, consistent with its localization in other cell types. Interestingly, arachidonic acid, the precursor to eiconsanoids, strongly induced Ost-beta expression in LEE-1 cells and a lipid mixture containing arachidonic acid also induced Ost-alpha. Overall, the present study describes the isolation of a novel marine cell line, and shows that this cell line expresses relatively high levels of Ost when cultured in the presence of arachidonic acid. Although the function of this transport protein in embryo-derived cells is unknown, it may play a role in the disposition of eicosanoids or steroid-derived molecules. PMID:18407792

Arachidonic acid in health and disease with focus on hypertension and diabetes mellitus: A review

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Undurti N. Das

2018-05-01

Full Text Available Arachidonic acid (AA 20:4n-6 is an essential component of cell membranes and modulates cell membrane fluidity. AA is metabolized by cyclo-oxygenase (COX, lipoxygenase (LOX and cytochrome P450 enzymes to form several metabolites that have important biological actions. Of all the actions, role of AA in the regulation of blood pressure and its ability to prevent both type 1 and type 2 diabetes mellitus seems to be interesting. Studies showed that AA and its metabolites especially, lipoxin A4 (LXA4 and epoxyeicosatrienoic acids (EETs, potent anti-inflammatory metabolites, have a crucial role in the pathobiology of hypertension and diabetes mellitus. AA, LXA4 and EETs regulate smooth muscle function and proliferation, voltage gated ion channels, cell membrane fluidity, membrane receptors, G-coupled receptors, PPARs, free radical generation, nitric oxide formation, inflammation, and immune responses that, in turn, participate in the regulation blood pressure and pathogenesis of diabetes mellitus. In this review, role of AA and its metabolites LXA4 and EETs in the pathobiology of hypertension, pre-eclampsia and diabetes mellitus are discussed. Based on several lines of evidences, it is proposed that a combination of aspirin and AA could be of benefit in the prevention and management of hypertension, pre-eclampsia and diabetes mellitus. Keywords: Arachidonic acid, Lipoxin A4, Hypertension, Pre-eclampsia, Diabetes mellitus, Inflammation, Cytokines, Free radicals, Nitric oxide

Lowering dietary n-6 polyunsaturated fatty acids: interaction with brain arachidonic and docosahexaenoic acids.

Science.gov (United States)

Alashmali, Shoug M; Hopperton, Kathryn E; Bazinet, Richard P

2016-02-01

Arachidonic (ARA) and docosahexaenoic (DHA) acids are the most abundant polyunsaturated fatty acids (PUFA) in the brain, where they have many biological effects, including on inflammation, cell-signaling, appetite regulation, and blood flow. The Western diet contains a high ratio of n-6: n-3 PUFA. Although interest in lowering this ratio has largely focused on increasing intake of n-3 PUFA, few studies have examined lowering dietary n-6 PUFA. This review will evaluate the effect of lowering dietary n-6 PUFA on levels and metabolism of ARA and DHA in animal models and in humans, with a primary focus on the brain. In animal models, lowering dietary ARA or linoleic acid generally lowers levels of brain ARA and raises DHA. Lowering dietary n-6 PUFA can also modulate the levels of ARA and DHA metabolizing enzymes, as well as their associated bioactive mediators. Human studies examining changes in plasma fatty acid composition following n-6 PUFA lowering demonstrate no changes in levels of ARA and DHA, though there is evidence of alterations in their respective bioactive mediators. Lowering dietary n-6 PUFA, in animal models, can alter the levels and metabolism of ARA and DHA in the brain, but it remains to be determined whether these changes are clinically meaningful.

Metabolism and incorporation of orally administrated arachidonic acid in rats

International Nuclear Information System (INIS)

Magni, F.; Kikawa, Y.; Jedlinski, A.; Lands, W.E.M.

1986-01-01

50 mg 3 H 2 H-20: 4n-6 was administered by oral intubation to rats maintained on a normal diet. The distribution of radioactive arachidonate esterified in the various tissues was similar to that for EFA-deficient rats from their previous study. The amount incorporated in the tissues was 14% in normal rats and 16% in EFA-deficient rats. At 24 hrs, the relative radioactivity in PC was higher (and lower in PE) than after 20 days in the previous study. Urine had 3-4% of initial radioactivity in the first 12 hours and only 1% more by 24 hours. Urine components were analyzed as methyl ester-methoxime-t-butyldimethylsilyl ethers. Most of the arachidonate metabolites in urine reported in the literature have expected ECL values between 26 to 32, whereas they found 68% of radioactivity with ECL values below 26. This represents a substantial divergence from arachidonate metabolite patterns described for injected prostaglandins and indicates the need of examining the metabolites formed from endogenously formed eicosanoids

12(R)-hydroxyicosatetraenoic acid: a cytochrome P450-dependent arachidonate metabolite that inhibits Na/sup +/, K/sup +/-ATPase in the cornea

Energy Technology Data Exchange (ETDEWEB)

Schwartzman, M.L.; Balazy, M.; Masferrer, J.; Abraham, N.G.; McGiff, J.C.; Murphy, R.C.

1987-11-01

When corneal microsomes were incubated with arachidonic acid in the presence of an NADPH-generating system, four polar metabolites (compounds A-D) were formed. Synthesis of these metabolites could be inhibited by carbon monoxide, SKF 525A, and anti-cytochrome c reductase antibodies. One of the metabolites, compound C, was found to inhibit partially purified Na/sup +/, K/sup +/-ATPase from the corneal epithelium in a dose-dependent manner. After compound C was purified by TLC and HPLC, it was found to have a UV absorption spectrum with a maximum absorbance at 236 nm suggesting the presence of a conjugated diene. Mass spectrometric analysis using positive- and negative-ionization modes was carried out on derivatized compound C. Abundant fragment ions were consistent with compound C being a monooxygenated derivative of arachidonic acid with a hydroxyl substituent at carbon-12 of the icosanoid backbone; all deuterium atoms from (/sup 2/H/sub 8/)arachidonate were retained in the structure. Compound C was characterized as a 12-hydroxyicosatetraenoic acid. However, only 12(R) isomer was found to be an inhibitor of the Na/sup +/, K/sup +/-ATPase from the corneal epithelium, suggesting that the biologically active compound C was 12(R)-hydroxyy-5,8,10,14-icosatetraenoic acid. Such an inhibitor of Na/sup +/, K/sup +/-ATPase synthesized in the cornea may have an important role in regulating ocular transparency and aqueous human secretion.

Hypersensitivity to norepinephrine in vasa deferentia from diabetic rats. Possible participation of metabolic products of arachidonic acid

Energy Technology Data Exchange (ETDEWEB)

Peredo, H; Agostini, M D; Gimeno, M F; Borda, E S

1984-08-01

Contractile responses to norepinephrine of the vas deferens isolated from normal and diabetic rats as well as tissue radio-conversion of exogenous arachidonic acid, were studied. Vasa deferentia from rats with acute streptozotocin-induced diabetes showed hypersensitivity to exogenous norepinephrine (NE). This increased contractile response was associated with the interaction of the agonist with alpha adrenoceptors. Inhibitors of cyclooxygenase increased and inhibitors of lipoxygenase(s) abolished the enhanced response to NE of diabetic vas deferens. Vasa deferentia from both normal and diabetic rats, converted (1-/sup 14/C)-arachidonic acid (AA) into PGF, PGE, PGD and thromboxane (TX) B2, but the % of AA metabolites formed was significantly higher in the diabetic than in the normal condition. Moreover, the predominant prostanoid generated by tissue preparations from diabetic animals was PGD2. Taken together the present experimental findings indicate that preparations from rats with acute streptozotocin-induced diabetes have an augmented reactivity towards NE, which appeared associated with changes in metabolites of AA generated via cyclooxygenase and lipoxygenase catalized pathways.

cPLA2a-evoked formation of arachidonic acid and lysophospholipids is required for exocytosis in mouse pancreatic ß-cells

DEFF Research Database (Denmark)

Juhl, Kirstine; Høy, Marianne; Olsen, Hervør L.

2003-01-01

Using capacitance measurements, we investigated the effects of intracellularly applied recombinant human cytosolic phospholipase A2 (cPLA2 ) and its lipolytic products arachidonic acid and lysophosphatidylcholine on Ca2+-dependent exocytosis in single mouse pancreatic -cells. cPLA2 dose dependently......–80 to 280–300. cPLA2 -stimulated exocytosis was antagonized by the specific cPLA2 inhibitor AACOCF3. Ca2+-evoked exocytosis was reduced by 40% in cells treated with AACOCF3 or an antisense oligonucleotide against cPLA2 . The action of cPLA2 was mimicked by a combination of arachidonic acid...... and lysophosphatidylcholine (470% stimulation) in which each compound alone doubled the exocytotic response. Priming of insulin-containing secretory granules has been reported to involve Cl- uptake through ClC-3 Cl- channels. Accordingly, the stimulatory action of cPLA2 was inhibited by the Cl- channel inhibitor DIDS...

cPLA2alpha-evoked formation of arachidonic acid and lysophospholipids is required for exocytosis in mouse pancreatic beta-cells

DEFF Research Database (Denmark)

Juhl, Kirstine; Høy, Marianne; Olsen, Hervør L

2003-01-01

Using capacitance measurements, we investigated the effects of intracellularly applied recombinant human cytosolic phospholipase A2 (cPLA2alpha) and its lipolytic products arachidonic acid and lysophosphatidylcholine on Ca2+-dependent exocytosis in single mouse pancreatic beta-cells. cPLA2alpha...... from 70-80 to 280-300. cPLA2alpha-stimulated exocytosis was antagonized by the specific cPLA2 inhibitor AACOCF3. Ca2+-evoked exocytosis was reduced by 40% in cells treated with AACOCF3 or an antisense oligonucleotide against cPLA2alpha. The action of cPLA2alpha was mimicked by a combination...... of arachidonic acid and lysophosphatidylcholine (470% stimulation) in which each compound alone doubled the exocytotic response. Priming of insulin-containing secretory granules has been reported to involve Cl- uptake through ClC-3 Cl- channels. Accordingly, the stimulatory action of cPLA2alpha was inhibited...

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.

Application of a ω-3 Desaturase with an Arachidonic Acid Preference to Eicosapentaenoic Acid Production in Mortierella alpina

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Chengfeng Ge

2018-01-01

Full Text Available In the industrial oleaginous fungus Mortierella alpina, the arachidonic acid (AA; C20:4; ω-6 fraction can reach 50% of the total fatty acids (TFAs in vivo. However, the eicosapentaenoic acid (EPA; C20:5; ω-3 fraction is less than 3% when this fungus is cultivated at a low temperature (12°C. Omega-3 fatty acid desaturase is a key enzyme in ω-3 long-chain polyunsaturated fatty acids biosynthesis pathways. To enhance EPA production, we transformed the ω-3 fatty acid desaturase (PaD17, which exhibits strong Δ-17 desaturase activity, into M. alpina, thus increasing the AA to EPA conversion rate to 49.8%. This PaD17-harboring M. alpina reconstruction strain produced 617 mg L−1 of EPA at room temperature in broth medium, this yield was increased to 1.73 g L−1 after culture medium optimization (i.e., about threefold higher than that under original culture conditions, with concomitant respective increases in dry cell weight and TFA content to 16.55 and 6.46 g L−1. These findings suggest a new platform for the future industrial production of EPA.

PLA2 - a major regulator of volume-sensitive taurine release in NIH3T3 fibroblasts

DEFF Research Database (Denmark)

Lambert, I. H.

2006-01-01

-lipoxygenase (5-LO) system is prevented by the 5-LO inhibitor ETH 615-139 and is reduced under hypertonic conditions. Exposure to the amphiphilic bee venom peptide melittin, which has no effect on the kinetic properties of PLA2 but promotes substrate replenishment, induces release of arachidonic acid...... conditions but has only a minor effect on the melittin-induced taurine efflux under hypertonic conditions. Bromoenol lactone and manoalide, known inhibitors of Ca2+-independent phospholipase A2 (iPLA2) and secretory phospholipase A2 (sPLA2), respectively, reduce arachidonic acid and taurine release from NIH3......T3 cells under hypotonic conditions and following addition of melittin. It is suggested that iPLA2/sPLA2 activity is responsible for the volume-sensitivity of taurine release in NIH3T3 mouse fibroblasts....

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

International Nuclear Information System (INIS)

Bito, L.Z.; Klein, E.M.

1982-01-01

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

Use of reversed-phase gel partition chromatography for the purification of chemically synthesized (5,6,8,9,11,12,14,15(n)) octadeuterium- and octatritium-labelled arachidonic acid

Energy Technology Data Exchange (ETDEWEB)

Wollard, P M; Lascelles, P T [Department of Chemical Pathology, Institute of Neurology, London, Great Britain; Hensby, C N [Hammersmith Hospital, London (UK). Postgraduate Medical School

1978-12-11

The development of a method is described for the preparation and purification of (5,6,8,9,11,12,14,15(n)-/sup 2/H)arachidonic acid (/sup 2/H/sub 8/-AA). The /sup 2/H/sub 8/-AA was chemically synthesised by the selective reduction of 5,8,11,14-eiconsatetraynoic acid (ETYA) with deuterium gas. Using reversed-phase partition chromatography on a Lipidex 5000 column support, it was shown that: (1) The reaction products could readily be separated from each other to yield /sup 2/H/sub 8/-AA of greater than 98% mass purity by gas chromatography. (2) Closely related C20 cis-ethylenic fatty acids differing only in the degree of unsaturation are efficiently separated. The resolution increases exponentially on saturation of double bonds. (3) Commercially available (5,6,8,9,11,12,14,15(n))octatritium-labelled arachidonic acid (/sup 3/H/sub 8/-AA) was readily purified. Both (/sup 3/H/sub 8/)- and (1-/sup 14/C)arachidonic acid (/sup 14/C-AA) co-chromatographed with /sup 2/H/sub 8/-AA. (4) The mass spectra of the methyl ester and trimethylsilyl ester of the purified /sup 2/H/sub 8/-AA showed molecular ions at m/e 326 and 384, respectively.

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

Science.gov (United States)

De, Soumita; Maroo, Niteeka; Saha, Piu; Hazra, Samik; Chatterjee, Mitali

2013-01-01

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. 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. 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. The present study indicates that PBE has promising analgesic activity, worthy of future pharmacological consideration.

Receptor-mediated inhibition of adenylate cyclase and stimulation of arachidonic acid release in 3T3 fibroblasts. Selective susceptibility to islet-activating protein, pertussis toxin

International Nuclear Information System (INIS)

Murayama, T.; Ui, M.

1985-01-01

Thrombin exhibited diverse effects on mouse 3T3 fibroblasts. It (a) decreased cAMP in the cell suspension, (b) inhibited adenylate cyclase in the Lubrol-permeabilized cell suspension in a GTP-dependent manner, increased releases of (c) arachidonic acid and (d) inositol from the cell monolayer prelabeled with these labeled compounds, (e) increased 45 Ca 2+ uptake into the cell monolayer, and (f) increased 86 Rb + uptake into the cell monolayer in a ouabain-sensitive manner. Most of the effects were reproduced by bradykinin, platelet-activating factor, and angiotensin II. The receptors for these agonists are thus likely to be linked to three separate effector systems: the adenylate cyclase inhibition, the phosphoinositide breakdown leading to Ca 2+ mobilization and phospholipase A2 activation, and the Na,K-ATPase activation. Among the effects of these agonists, (a), (b), (c), and (e) were abolished, but (d) and (f) were not, by prior treatment of the cells with islet-activating protein (IAP), pertussis toxin, which ADP-ribosylates the Mr = 41,000 protein, the alpha-subunit of the inhibitory guanine nucleotide regulatory protein (Ni), thereby abolishing receptor-mediated inhibition of adenylate cyclase. The effects (a), (c), (d), and (e) of thrombin, but not (b), were mimicked by A23187, a calcium ionophore. The effects of A23187, in contrast to those of receptor agonists, were not affected by the treatment of cells with IAP. Thus, the IAP substrate, the alpha-subunit of Ni, or the protein alike, may play an additional role in signal transduction arising from the Ca 2+ -mobilizing receptors, probably mediating process(es) distal to phosphoinositide breakdown and proximal to Ca 2+ gating

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

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

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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.

Docosahexaenoic acid (DHA) and arachidonic acid (ARA) balance in developmental outcomes.

Science.gov (United States)

Colombo, John; Jill Shaddy, D; Kerling, Elizabeth H; Gustafson, Kathleen M; Carlson, Susan E

2017-06-01

The DHA Intake and Measurement of Neural Development (DIAMOND) trial represents one of only a few studies of the long-term dose-response effects of LCPUFA-supplemented formula feeding during infancy. The trial contrasted the effects of four formulations: 0.00% docosahexaenoic acid (DHA)/0.00% arachidonic acid (ARA), 0.32% DHA/0.64% ARA, 0.64% DHA/0.64% ARA, and 0.96% DHA/0.64% ARA against a control condition (0.00% DHA/0.00% ARA). The results of this trial have been published elsewhere, and show improved cognitive outcomes for infants fed supplemented formulas, but a common finding among many of the outcomes show a reduction of benefit for the highest DHA dose (i.e., 0.96%DHA/0.64% ARA, that is, a DHA: ARA ratio 1.5:1.0). The current paper gathers and summarizes the evidence for the reduction of benefit at this dose, and in an attempt to account for this reduced benefit, presents for the first time data from infants' red blood cell (RBC) assays taken at 4 and 12 months of age. Those assays indicate that blood DHA levels generally rose with increased DHA supplementation, although those levels tended to plateau as the DHA-supplemented level exceeded 0.64%. Perhaps more importantly, ARA levels showed a strong inverted-U function in response to increased DHA supplementation; indeed, infants assigned to the formula with the highest dose of DHA (and highest DHA/ARA ratio) showed a reduction in blood ARA relative to more intermediate DHA doses. This finding raises the possibility that reduced ARA may be responsible for the reduction in benefit on cognitive outcomes seen at this dose. The findings implicate the DHA/ARA balance as an important variable in the contribution of LCPUFAs to cognitive and behavioral development in infancy. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

International Nuclear Information System (INIS)

Carlson, R.O.

1990-01-01

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

Modulation of hypericin photodynamic therapy by pretreatment with 12 various inhibitors of arachidonic acid metabolism in colon adenocarcinoma HT-29 cells

Czech Academy of Sciences Publication Activity Database

Kleban, J.; Mikeš, J.; Szilárdiová, B.; Koval, J.; Sačková, V.; Solár, P.; Horváth, Viktor; Hofmanová, Jiřina; Kozubík, Alois; Fedoročko, P.

2007-01-01

Roč. 83, č. 5 (2007), s. 1174-1185 ISSN 0031-8655 R&D Projects: GA AV ČR(CZ) 1QS500040507 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : hypericin * photodynamic therapy * arachidonic acid inhibitors Subject RIV: BO - Biophysics Impact factor: 2.172, year: 2007

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

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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.

Blood fatty acid composition of pregnant and nonpregnant Korean women: red cells may act as a reservoir of arachidonic acid and docosahexaenoic acid for utilization by the developing fetus.

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Ghebremeskel, K; Min, Y; Crawford, M A; Nam, J H; Kim, A; Koo, J N; Suzuki, H

2000-05-01

Relative fatty acid composition of plasma and red blood cell (RBC) choline phosphoglycerides (CPG), and RBC ethanolamine phosphoglycerides (EPG) of pregnant (n = 40) and nonpregnant, nonlactating (n = 40), healthy Korean women was compared. The two groups were of the same ethnic origin and comparable in age and parity. Levels of arachidonic (AA) and docosahexaenoic (DHA) acids were lower (P mothers were mobilizing membrane AA and DHA to meet the high fetal requirement for these nutrients. It may also suggest that RBC play a role as a potential store of AA and DHA and as a vehicle for the transport of these fatty acids from maternal circulation to the placenta to be utilized by the developing fetus.

Targeting arachidonic acid pathway by natural products for cancer prevention and therapy.

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Yarla, Nagendra Sastry; Bishayee, Anupam; Sethi, Gautam; Reddanna, Pallu; Kalle, Arunasree M; Dhananjaya, Bhadrapura Lakkappa; Dowluru, Kaladhar S V G K; Chintala, Ramakrishna; Duddukuri, Govinda Rao

2016-10-01

Arachidonic acid (AA) pathway, a metabolic process, plays a key role in carcinogenesis. Hence, AA pathway metabolic enzymes phospholipase A 2 s (PLA 2 s), cyclooxygenases (COXs) and lipoxygenases (LOXs) and their metabolic products, such as prostaglandins and leukotrienes, have been considered novel preventive and therapeutic targets in cancer. Bioactive natural products are a good source for development of novel cancer preventive and therapeutic drugs, which have been widely used in clinical practice due to their safety profiles. AA pathway inhibitory natural products have been developed as chemopreventive and therapeutic agents against several cancers. Curcumin, resveratrol, apigenin, anthocyans, berberine, ellagic acid, eugenol, fisetin, ursolic acid, [6]-gingerol, guggulsteone, lycopene and genistein are well known cancer chemopreventive agents which act by targeting multiple pathways, including COX-2. Nordihydroguaiaretic acid and baicalein can be chemopreventive molecules against various cancers by inhibiting LOXs. Several PLA 2 s inhibitory natural products have been identified with chemopreventive and therapeutic potentials against various cancers. In this review, we critically discuss the possible utility of natural products as preventive and therapeutic agents against various oncologic diseases, including prostate, pancreatic, lung, skin, gastric, oral, blood, head and neck, colorectal, liver, cervical and breast cancers, by targeting AA pathway. Further, the current status of clinical studies evaluating AA pathway inhibitory natural products in cancer is reviewed. In addition, various emerging issues, including bioavailability, toxicity and explorability of combination therapy, for the development of AA pathway inhibitory natural products as chemopreventive and therapeutic agents against human malignancy are also discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Early docosahexaenoic and arachidonic acid supplementation in extremely-low-birth-weight infants.

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Robinson, Daniel T; Caplan, Michael; Carlson, Susan E; Yoder, Rachel; Murthy, Karna; Frost, Brandy

2016-10-01

Extremely-low-birth-weight (ELBW) infants accrue large deficits in docosahexaenoic acid (DHA) and arachidonic acid (ARA) and require improved supplementation strategies. We hypothesized that once daily DHA+ARA drops applied to buccal mucosa will increase blood levels. Thirty ELBW infants were randomized to receive DHA 20 mg/kg/d + ARA 40 or 60 mg/kg/d + ARA 120 mg/kg/d or placebo within 72 h of age for 8 wk duration. Red blood cell phospholipid levels of DHA (primary) and ARA (secondary) were measured at 2 and 8 wk of age. Twenty-eight survivors with a median birth weight of 806 g completed dosing and sampling. Red blood cell levels were similar between the three groups at 2 wk (DHA: 4.62 wt% (interquartile range (IQR) 4.1-5.5) for all, P = 0.29 between groups; ARA: 21.1 wt% (IQR 18.78-22.6) for all, P = 0.41 between groups) and 8 wk (DHA: 6.0 wt% (IQR 5.1-7.1) for all, P = 0.57 between groups; ARA: 20.1 wt% (IQR 18.3-23.1) for all, P = 0.63 between groups). DHA in all infants showed a median increase of 31% from 2 to 8 wk (P 0.6). Daily buccal DHA and ARA supplements did not affect fatty acid levels in ELBW infants.

Impact of arachidonic versus eicosapentaenoic acid on exotonin-induced lung vascular leakage: relation to 4-series versus 5-series leukotriene generation.

Science.gov (United States)

Grimminger, F; Wahn, H; Mayer, K; Kiss, L; Walmrath, D; Seeger, W

1997-02-01

Escherichia coli hemolysin (HlyA) is a proteinaceous pore-forming exotoxin that is implicated as a significant pathogenicity factor in extraintestinal E. coli infections including sepsis. In perfused rabbit lungs, subcytolytic concentrations of the toxin evoke thromboxane-mediated vasoconstriction and prostanoid-independent protracted vascular permeability increase (11). In the present study, the influence of submicromolar concentrations of free arachidonic acid (AA) and eicosapentaenoic acid (EPA) on the HlyA-induced leakage response was investigated. HlyA at concentration from 0.02 to 0.06 hemolytic units/ml provoked a dose-dependent, severalfold increase in the capillary filtration coefficient (Kfc), accompanied by the release of leukotriene(LT)B4, LTC4, and LTE4 into the recirculating buffer fluid. Simultaneous application of 100 nmol/L AA markedly augmented the HlyA-elicited leakage response, concomitant with an amplification of LTB4 release and a change in the kinetics of cysteinyl-LT generation. In contrast, 50 to 200 nmol/L EPA suppressed in a dose-dependent manner the HlyA-induced increase in Kfc values. This was accompanied by a blockage of 4-series LT generation and a dose-dependent appearance of LTB5, LTC5, and LTE5. In addition, EPA fully antagonized the AA-induced amplification of the HlyA-provoked Kfc increase, again accompanied by a shift from 4-series to 5-series LT generation. We conclude that the vascular leakage provoked by HlyA in rabbit lungs is differentially influenced by free AA versus free EPA, related to the generation of 4- versus 5-series leukotrienes. The composition of lipid emulsions used for parenteral nutrition may thus influence inflammatory capillary leakage.

The Omega-3 Fatty Acid Docosahexaenoic Acid Modulates Inflammatory Mediator Release in Human Alveolar Cells Exposed to Bronchoalveolar Lavage Fluid of ARDS Patients

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Paolo Cotogni

2015-01-01

Full Text Available Background. This study investigated whether the 1 : 2 ω-3/ω-6 ratio may reduce proinflammatory response in human alveolar cells (A549 exposed to an ex vivo inflammatory stimulus (bronchoalveolar lavage fluid (BALF of acute respiratory distress syndrome (ARDS patients. Methods. We exposed A549 cells to the BALF collected from 12 ARDS patients. After 18 hours, fatty acids (FA were added as docosahexaenoic acid (DHA, ω-3 and arachidonic acid (AA, ω-6 in two ratios (1 : 2 or 1 : 7. 24 hours later, in culture supernatants were evaluated cytokines (TNF-α, IL-6, IL-8, and IL-10 and prostaglandins (PGE2 and PGE3 release. The FA percentage content in A549 membrane phospholipids, content of COX-2, level of PPARγ, and NF-κB binding activity were determined. Results. The 1 : 2 DHA/AA ratio reversed the baseline predominance of ω-6 over ω-3 in the cell membranes (P < 0.001. The proinflammatory cytokine release was reduced by the 1 : 2 ratio (P < 0.01 to <0.001 but was increased by the 1 : 7 ratio (P < 0.01. The 1 : 2 ratio reduced COX-2 and PGE2 (P < 0.001 as well as NF-κB translocation into the nucleus (P < 0.01, while it increased activation of PPARγ and IL-10 release (P < 0.001. Conclusion. This study demonstrated that shifting the FA supply from ω-6 to ω-3 decreased proinflammatory mediator release in human alveolar cells exposed to BALF of ARDS patients.

Anti-Inflammatory Effects of Benfotiamine are Mediated Through the Regulation of Arachidonic Acid Pathway in Macrophages

Science.gov (United States)

Shoeb, Mohammad; Ramana, Kota V

2011-01-01

Benfotiamine, a lipid-soluble analogue of vitamin B1, is a potent anti-oxidant that is used as a food supplement for the treatment of diabetic complications. Our recent study indicates a novel role of benfotiamine in the prevention of bacterial endotoxin, lipopolysaccharide (LPS)-induced cytotoxicity and inflammatory response in murine macrophages. Nevertheless, it remains unclear how benfotiamine mediates anti-inflammatory effects. In this study, we investigated the anti-inflammatory role of benfotiamine in regulating the arachidonic acid (AA) pathway generated inflammatory lipid mediators in RAW 264.7 macrophages. Benfotiamine prevented the LPS-induced activation of cPLA2 and release of AA metabolites such as leukotrienes (LTB4), prostaglandin E2 (PGE2), thromboxanes 2 (TXB2) and prostacyclin (PGI2) in macrophages. Further, LPS-induced expressions of AA metabolizing enzymes such as COX-2, LOX-5, TXB synthase and PGI2 synthase were significantly blocked by benfotiamine. Furthermore, benfotiamine prevented the LPS-induced phosphorylation of ERK1/2 and expression of transcription factors NF-kB, and Egr-1. Benfotiamine also prevented the LPS-induced oxidative stress and protein-HNE adducts formation. Most importantly, as compared to specific COX-2 and LOX-5 inhibitors, benfotiamine significantly prevented the LPS-induced macrophage death and monocytes adhesion to endothelial cells. Thus, our studies indicate that the dual regulation of COX and LOX pathways in AA metabolism could be a novel mechanism by which benfotiamine exhibits its potential anti-inflammatory response. PMID:22067901

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

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

2003-04-11

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

Aryl hydrocarbon receptor–ligand axis mediates pulmonary fibroblast migration and differentiation through increased arachidonic acid metabolism

International Nuclear Information System (INIS)

Su, Hsiang-Han; Lin, Hsin-Ting; Suen, Jau-Ling; Sheu, Chau Chyun; Yokoyama, Kazunari K.; Huang, Shau-Ku; Cheng, Chih Mei

2016-01-01

Pulmonary fibroblast migration and differentiation are critical events in fibrogenesis; meanwhile, fibrosis characterizes the pathology of many respiratory diseases. The role of aryl hydrocarbon receptor (AhR), a unique cellular chemical sensor, has been suggested in tissue fibrosis, but the mechanisms through which the AhR-ligand axis influences the fibrotic process remain undefined. In this study, the potential impact of the AhR-ligand axis on pulmonary fibroblast migration and differentiation was analyzed using human primary lung fibroblasts HFL-1 and CCL-202 cells. Boyden chamber-based cell migration assay showed that activated AhR in HFL-1cells significantly enhanced cell migration in response to 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), and a known AhR antagonist, CH223191, inhibited its migratory activity. Furthermore, the calcium mobilization and subsequent upregulated expression of arachidonic acid metabolizing enzymes, including cyclooxygenase2 (COX-2) and 5-lipoxygenase (5-LOX), were observed in TCDD-treated HFL-1 cells, concomitant with elevated levels of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) secretion. Also, significantly increased expression of α-smooth muscle actin α-SMA), a fibroblast differentiation marker, was also noted in TCDD-treated HFL-1 cells (p < 0.05), resulting in a dynamic change in cytoskeleton protein levels and an increase in the nuclear translocation of the myocardin-related transcription factor. Moreover, the enhanced levels of α-SMA expression and fibroblast migration induced by TCDD, PGE2 and LTB4 were abrogated by selective inhibitors for COX-2 and 5-LOX. Knockdown of AhR by siRNA Completely diminished intracellular calcium uptake and reduced α-SMA protein verified by promoter-reporter assays and chromatin immunoprecipitation. Taken together, our results suggested the importance of the AhR-ligand axis in fibroblast migration and differentiation through its capacity in enhancing arachidonic acid metabolism.

Arachidonic acid triggers an oxidative burst in leukocytes

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Pompeia C.

2003-01-01

Full Text Available The change in cellular reducing potential, most likely reflecting an oxidative burst, was investigated in arachidonic acid- (AA stimulated leukocytes. The cells studied included the human leukemia cell lines HL-60 (undifferentiated and differentiated into macrophage-like and polymorphonuclear-like cells, Jurkat and Raji, and thymocytes and macrophages from rat primary cultures. The oxidative burst was assessed by nitroblue tetrazolium reduction. AA increased the oxidative burst until an optimum AA concentration was reached and the burst decreased thereafter. In the leukemia cell lines, optimum concentration ranged from 200 to 400 µM (up to 16-fold, whereas in rat cells it varied from 10 to 20 µM. Initial rates of superoxide generation were high, decreasing steadily and ceasing about 2 h post-treatment. The continuous presence of AA was not needed to stimulate superoxide generation. It seems that the NADPH oxidase system participates in AA-stimulated superoxide production in these cells since the oxidative burst was stimulated by NADPH and inhibited by N-ethylmaleimide, diphenyleneiodonium and superoxide dismutase. Some of the effects of AA on the oxidative burst may be due to its detergent action. There apparently was no contribution of other superoxide-generating systems such as xanthine-xanthine oxidase, cytochromes P-450 and mitochondrial electron transport chain, as assessed by the use of inhibitors. Eicosanoids and nitric oxide also do not seem to interfere with the AA-stimulated oxidative burst since there was no systematic effect of cyclooxygenase, lipoxygenase or nitric oxide synthase inhibitors, but lipid peroxides may play a role, as indicated by the inhibition of nitroblue tetrazolium reduction promoted by tocopherol.

Peroxisome proliferation activation receptor alpha modulation of Ca2+-regulated exocytosis via arachidonic acid in guinea-pig antral mucous cells.

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Sawabe, Yukinori; Shimamoto, Chikao; Sakai, Akiko; Kuwabara, Hiroko; Saad, Adel H; Nakano, Takashi; Takitani, Kimitaka; Tamai, Hiroshi; Mori, Hiroshi; Marunaka, Yoshinori; Nakahari, Takashi

2010-08-01

Indomethacin (IDM, 10 microm), not aspirin (ASA; 10 microm), enhanced the Ca(2+)-regulated exocytosis stimulated by 1 microm acetylcholine (ACh) in guinea-pig antral mucous cells. Indomethacin inhibits prostaglandin G/H (PGG/H) and 15R-hydroperoxy-eicosatetraenoic acid (15R-HPETE) production from arachidonic acid (AA), while ASA inhibits PGG/H production but accelerates 15R-HPETE production. This suggests that IDM accumulates AA. Arachidonic acid (2 microm) enhanced Ca(2+)-regulated exocytosis in antral mucous cells to a similar extent to IDM. Moreover, a stable analogue of AA, arachidonyltrifluoromethyl ketone (AACOCF(3)), also enhanced Ca(2+)-regulated exocytosis, indicating that AA, not products from AA, enhances Ca(2+)-regulated exocytosis. We hypothesized that AA activates peroxisome proliferation activation receptor alpha (PPARalpha), because AA is a natural ligand for PPARalpha. A PPARalpha agonist (WY14643; 1 microm) enhanced Ca(2+)-regulated exocytosis, and a PPARalpha blocker (MK886; 50 microm) abolished the enhancement of Ca(2+)-regulated exocytosis induced by AA, IDM, AACOCF(3) and WY14643. Western blotting and immunohistochemical examinations demonstrated that PPARalpha exists in antral mucous cells. Moreover, MK886 decreased the frequency of Ca(2+)-regulated exocytosis activated by 1 microm ACh or 2 microm thapsigargin alone by 25-30%. Thus, ACh stimulates AA accumulation via an [Ca(2+)](i) increase, which activates PPARalpha, leading to enhancement of Ca(2+)-regulated exocytosis in antral mucous cells. A novel autocrine mechanism mediated via PPARalpha enhances Ca(2+)-regulated exocytosis in guinea-pig antral mucous cells.

Influence of whole-body gamma irradiation upon arachidonic acid metabolism in rat platelets

International Nuclear Information System (INIS)

Lognonne, J.L.; Ducousso, R.; Rocquet, G.; Kergonou, J.F.

1985-01-01

The effects of whole-body gamma irradiation (8.4 Gy) were studied on arachidonic acid (AA) metabolism in rat's blood platelets, from day D + 1 to day D + 10 after irradiation. AA conversion into thromboxane B 2 (TxB 2 ) increased at D + 1 and then gradually decreased to very low values from D + 7 to D + 10. This decrease in the conversion of exogenous AA into TxB 2 was due to a lower AA incorporation into platelets and not to a decrease of cyclooxygenase and thromboxane-synthetase activities. AA incorporation into membrane phospholipids of blood platelets was much more decreased than AA incorporation into whole platelets; moreover, the lipid composition of the platelet membranes was markedly modified after irradiation, which must have resulted in structural and functional changes in these membranes; from these effects of whole-body gamma irradiation on platelets, the latter's membranes appeared as a major site of in vivo radiation damage in these cells

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

International Nuclear Information System (INIS)

Lipchik, R.J.; Chauncey, J.B.; Paine, R.; Simon, R.H.; Peters-Golden, M.

1990-01-01

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

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

International Nuclear Information System (INIS)

Storniolo, C.E.; Moreno, J.J.

2016-01-01

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. [es

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

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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.

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

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

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

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,

Mildly abnormal general movement quality in infants is associated with higher Mead acid and lower arachidonic acid and shows a U-shaped relation with the DHA/AA ratio.

Science.gov (United States)

van Goor, S A; Schaafsma, A; Erwich, J J H M; Dijck-Brouwer, D A J; Muskiet, F A J

2010-01-01

We showed that docosahexaenoic acid (DHA) supplementation during pregnancy and lactation was associated with more mildly abnormal (MA) general movements (GMs) in the infants. Since this finding was unexpected and inter-individual DHA intakes are highly variable, we explored the relationship between GM quality and erythrocyte DHA, arachidonic acid (AA), DHA/AA and Mead acid in 57 infants of this trial. MA GMs were inversely related to AA, associated with Mead acid, and associated with DHA/AA in a U-shaped manner. These relationships may indicate dependence of newborn AA status on synthesis from linoleic acid. This becomes restricted during the intrauterine period by abundant de novo synthesis of oleic and Mead acids from glucose, consistent with reduced insulin sensitivity during the third trimester. The descending part of the U-shaped relation between MA GMs and DHA/AA probably indicates DHA shortage next to AA shortage. The ascending part may reflect a different developmental trajectory that is not necessarily unfavorable. Copyright 2009 Elsevier Ltd. All rights reserved.

LysoPC and PAF Trigger Arachidonic Acid Release by Divergent Signaling Mechanisms in Monocytes

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Janne Oestvang

2011-01-01

Full Text Available Oxidized low-density lipoproteins (LDLs play an important role during the development of atherosclerosis characterized by intimal inflammation and macrophage accumulation. A key component of LDL is lysophosphatidylcholine (lysoPC. LysoPC is a strong proinflammatory mediator, and its mechanism is uncertain, but it has been suggested to be mediated via the platelet activating factor (PAF receptor. Here, we report that PAF triggers a pertussis toxin- (PTX- sensitive intracellular signaling pathway leading to sequential activation of sPLA2, PLD, cPLA2, and AA release in human-derived monocytes. In contrast, lysoPC initiates two signaling pathways, one sequentially activating PLD and cPLA2, and a second parallel PTX-sensitive pathway activating cPLA2 with concomitant activation of sPLA2, all leading to AA release. In conclusion, lysoPC and PAF stimulate AA release by divergent pathways suggesting involvement of independent receptors. Elucidation of monocyte lysoPC-specific signaling mechanisms will aid in the development of novel strategies for atherosclerosis prevention, diagnosis, and therapy.

Diffusion of intracerebrally injected [1-14C]arachidonic acid and [2-3H]glycerol in the mouse brain. Effects of ischemia and electroconvulsive shock

International Nuclear Information System (INIS)

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

1982-01-01

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

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

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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.

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

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...... metamorphosis. Initiation of metamorphosis (i.e. start of eye migration) was related to the size of larvae and not related to ARA or EPA content. Dietary EPA or DHA did not retard the advance of eye migration. More than 90 % of highly malpigmented juveniles, (i.e. "albinos") had a permanent aberrant eye...

Anti-inflammatory effects of benfotiamine are mediated through the regulation of the arachidonic acid pathway in macrophages.

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Shoeb, Mohammad; Ramana, Kota V

2012-01-01

Benfotiamine, a lipid-soluble analogue of vitamin B1, is a potent antioxidant that is used as a food supplement for the treatment of diabetic complications. Our recent study (U.C. Yadav et al., Free Radic. Biol. Med. 48:1423-1434, 2010) indicates a novel role for benfotiamine in the prevention of bacterial endotoxin, lipopolysaccharide (LPS)-induced cytotoxicity and inflammatory response in murine macrophages. Nevertheless, it remains unclear how benfotiamine mediates anti-inflammatory effects. In this study, we investigated the anti-inflammatory role of benfotiamine in regulating arachidonic acid (AA) pathway-generated inflammatory lipid mediators in RAW264.7 macrophages. Benfotiamine prevented the LPS-induced activation of cPLA2 and release of AA metabolites such as leukotrienes, prostaglandin E2, thromboxane 2 (TXB2), and prostacyclin (PGI2) in macrophages. Further, LPS-induced expression of AA-metabolizing enzymes such as COX-2, LOX-5, TXB synthase, and PGI2 synthase was significantly blocked by benfotiamine. Furthermore, benfotiamine prevented the LPS-induced phosphorylation of ERK1/2 and expression of transcription factors NF-κB and Egr-1. Benfotiamine also prevented the LPS-induced oxidative stress and protein-HNE adduct formation. Most importantly, compared to specific COX-2 and LOX-5 inhibitors, benfotiamine significantly prevented LPS-induced macrophage death and monocyte adhesion to endothelial cells. Thus, our studies indicate that the dual regulation of the COX and LOX pathways in AA metabolism could be a novel mechanism by which benfotiamine exhibits its potential anti-inflammatory response. Copyright © 2011 Elsevier Inc. All rights reserved.

Monoglyceride lipase as a drug target: At the crossroads of arachidonic acid metabolism and endocannabinoid signaling.

Science.gov (United States)

Grabner, Gernot F; Zimmermann, Robert; Schicho, Rudolf; Taschler, Ulrike

2017-07-01

Monoglyerides (MGs) are short-lived, intermediary lipids deriving from the degradation of phospho- and neutral lipids, and monoglyceride lipase (MGL), also designated as monoacylglycerol lipase (MAGL), is the major enzyme catalyzing the hydrolysis of MGs into glycerol and fatty acids. This distinct function enables MGL to regulate a number of physiological and pathophysiological processes since both MGs and fatty acids can act as signaling lipids or precursors thereof. The most prominent MG species acting as signaling lipid is 2-arachidonoyl glycerol (2-AG) which is the most abundant endogenous agonist of cannabinoid receptors in the body. Importantly, recent observations demonstrate that 2-AG represents a quantitatively important source for arachidonic acid, the precursor of prostaglandins and other inflammatory mediators. Accordingly, MGL-mediated 2-AG degradation affects lipid signaling by cannabinoid receptor-dependent and independent mechanisms. Recent genetic and pharmacological studies gave important insights into MGL's role in (patho-)physiological processes, and the enzyme is now considered as a promising drug target for a number of disorders including cancer, neurodegenerative and inflammatory diseases. This review summarizes the basics of MG (2-AG) metabolism and provides an overview on the therapeutic potential of MGL. Copyright © 2017 Elsevier Inc. All rights reserved.

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.

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

Czech Academy of Sciences Publication Activity Database

Šerý, Omar; Hlinecká, L.; Povová, J.; Bonczek, Ondřej; Zeman, T.; Janout, V.; Ambrož, P.; Khan, N. A.; Balcar, V. J.

2016-01-01

Roč. 362, č. 1 (2016), s. 27-32 ISSN 0022-510X Institutional support: RVO:67985904 Keywords : Arachidonic acid * genetics * inflammation * leukotrienes * curcumin Subject RIV: FH - Neurology Impact factor: 2.295, year: 2016

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

Science.gov (United States)

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

2016-09-01

A significant increase in cyclooxygenase 2 (COX2) gene expression has been shown to promote cylcooxygenase-dependent colon cancer development. Controversy associated with the role of COX2 inhibitors indicates that additional work is needed to elucidate the effects of arachidonic acid (AA)-derived (cyclooxygenase and lipoxygenase) eicosanoids in cancer initiation, progression, and metastasis. We have recently developed a novel Fads1 knockout mouse model that allows for the investigation of AA-dependent eicosanoid deficiency without the complication of essential fatty acid deficiency. Interestingly, the survival rate of Fads1-null mice is severely compromised after 2 months on a semi-purified AA-free diet, which precludes long-term chemoprevention studies. Therefore, in this study, dietary AA levels were titrated to determine the minimal level required for survival, while maintaining a distinct AA-deficient phenotype. Null mice supplemented with AA (0.1%, 0.4%, 0.6%, 2.0%, w/w) in the diet exhibited a dose-dependent increase (P sibling littermate control mice. These data indicate that (i) basal/minimal dietary AA supplementation (0.6%) expands the utility of the Fads1-null mouse model for long-term cancer prevention studies and (ii) that AA content in the colonic epithelium modulates colon cancer risk. Cancer Prev Res; 9(9); 750-7. ©2016 AACR. ©2016 American Association for Cancer Research.

An updated review of worldwide levels of docosahexaenoic and arachidonic acid in human breast milk by region.

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Fu, Yuanqing; Liu, Xin; Zhou, Bing; Jiang, Alice C; Chai, Lingying

2016-10-01

We aimed to evaluate the DHA and arachidonic acid (AA) levels in human breast milk worldwide by country, region and socio-economic status. Descriptive review conducted on English publications reporting breast-milk DHA and AA levels. We systematically searched and identified eligible literature in PubMed from January 1980 to July 2015. Data on breast-milk DHA and AA levels from women who had given birth to term infants were included. Seventy-eight studies from forty-one countries were included with 4163 breast-milk samples of 3746 individuals. Worldwide mean levels of DHA and AA in breast milk were 0·37 (sd 0·11) % and 0·55 (sd 0·14) % of total fatty acids, respectively. The breast-milk DHA levels from women with accessibility to marine foods were significantly higher than those from women without accessibility (0·35 (sd 0·20) % v. 0·25 (sd 0·14) %, Pworldwide variation in breast-milk DHA and AA levels and underlines the need for future population- or region-specific investigations.

Arachidonic Acid Metabolite as a Novel Therapeutic Target in Breast Cancer Metastasis

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Thaiz F. Borin

2017-12-01

Full Text Available Metastatic breast cancer (BC (also referred to as stage IV spreads beyond the breast to the bones, lungs, liver, or brain and is a major contributor to the deaths of cancer patients. Interestingly, metastasis is a result of stroma-coordinated hallmarks such as invasion and migration of the tumor cells from the primary niche, regrowth of the invading tumor cells in the distant organs, proliferation, vascularization, and immune suppression. Targeted therapies, when used as monotherapies or combination therapies, have shown limited success in decreasing the established metastatic growth and improving survival. Thus, novel therapeutic targets are warranted to improve the metastasis outcomes. We have been actively investigating the cytochrome P450 4 (CYP4 family of enzymes that can biosynthesize 20-hydroxyeicosatetraenoic acid (20-HETE, an important signaling eicosanoid involved in the regulation of vascular tone and angiogenesis. We have shown that 20-HETE can activate several intracellular protein kinases, pro-inflammatory mediators, and chemokines in cancer. This review article is focused on understanding the role of the arachidonic acid metabolic pathway in BC metastasis with an emphasis on 20-HETE as a novel therapeutic target to decrease BC metastasis. We have discussed all the significant investigational mechanisms and put forward studies showing how 20-HETE can promote angiogenesis and metastasis, and how its inhibition could affect the metastatic niches. Potential adjuvant therapies targeting the tumor microenvironment showing anti-tumor properties against BC and its lung metastasis are discussed at the end. This review will highlight the importance of exploring tumor-inherent and stromal-inherent metabolic pathways in the development of novel therapeutics for treating BC metastasis.

Ultrastructural autoradiographic localization of exogenous arachidonic acid in cultured endothelial and smooth muscle cells

International Nuclear Information System (INIS)

Tasca, S.I.; Galis, Z.

1988-01-01

The uptake and intracellular localization of exogenous arachidonic acid (AA) were investigated in cultured endothelial (EC) and smooth muscle cells (SMC) isolated from bovine aorta. The [ 14 C]AA uptake was assessed biochemically and by light and electron microscopic autoradiography. The highest values of silver grain surface density were associated with the mitochondria, lysosomes, and the Golgi apparatus of the EC. The grain linear density was greater on the nuclear envelope than on plasmalemma. On SMC, the grain density was highest on lipid droplets whereas the linear densities of the nuclear envelope and plasmalemma were similar. The share of each subcellular compartment in the AA distribution was estimated as the percentage of the individual silver grain count out of the total cell-associated radioactivity. The results showed that cytoplasm (including endoplasmic reticulum, ribosomes, and small vesicles) made the main contribution followed by the nucleus and at lower values by other organelles. These subcompartments may represent the intracellular sites from which AA could be mobilized for prostanoid synthesis by EC and SMC. (author)

Oxidation of esterified arachidonate by rat liver microsomes

International Nuclear Information System (INIS)

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

1986-01-01

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- 14 C) was incorporated into rat liver microsomes and NADPH-supported peroxidation was carried out at 37 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 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 3+ and since product formation is unaffected in the presence of carbon monoxide

Prostaglandin E2 release from dermis regulates sodium permeability of frog skin epithelium

DEFF Research Database (Denmark)

Rytved, Klaus A.; Brodin, Birger; Nielsen, Robert

1995-01-01

Arachidonic acid, cAMP, epithelium, frog skin, intracellular calcium, prostaglandin E*U2, sodium transport, tight epithelium.......Arachidonic acid, cAMP, epithelium, frog skin, intracellular calcium, prostaglandin E*U2, sodium transport, tight epithelium....

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

Science.gov (United States)

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

2015-01-01

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

Thiyl radical-induced cis-trans-isomerization of arachidonic acid inhibits prostaglandin metabolism

International Nuclear Information System (INIS)

Kratzsch, S.; Droessler, K.; Sprinz, H.; Brede, O.

2002-01-01

Complete text of publication follows. Thiyl radicals radiolytically generated from thiophenol in methanolic solution are known to isomerise double bonds of poly-unsaturated fatty acids (PUFA). γ-irradiating of such a system containing all-cis 5,8,11,14 eicosatetraenoic acid (arachidonic acid, AA) with low doses (0.1-0.8 kGy) results in a mixture of 8 to 32% mono-trans-isomers. Here we report about the influence of mono-trans-AA on the primary steps of AA-metabolism and prostaglandin synthesis, catalysed by cyclooxygenase (COX). In the cell-free model system the reaction of COX-1 with AA was analysed by controlling the oxygen level during the enzymatic reaction. As an example, a mixture of a low quantity of mono-trans-isomerized AA (10%) and 90% all-cis-isomer exhibits a marked reduced oxygen consumption by 45%. As further proofs - the yield of reactive oxygen species (ROS) generated by the COX-coupled peroxidase reaction was detected, - and the COX-1 activity in presence of different amounts of trans-AA was characterized using a photometric assay based on the oxidation of TMPD. All these methods indicated semiquantitatively a reduced activity of COX-1, depending on the trans-isomer yield. Therefore, an inhibition of COX-1 activity by only one trans-double-bond in AA could be concluded. Furthermore, in vitro cell-line experiments were performed analysing the influence of mono-trans-isomerized AA on the activity of the cell-own COX-2. Hence, VD 3 -differentiated and LPS-stimulated monocyte-like cells were incubated with mono-trans-AA and ROS-production was detected by the chemiluminescence measurements mentioned above. Compared to the reaction with all-cis-AA we found a considerable lowered formation of ROS. Likewise, we obtained a reduced PGE 2 -expression between 15 and 40% for cells treated with 8 to 29% trans-AA. The model as well as in vivo experiments demonstrate an inhibition effect of mono-trans-AA and give rise for postulating an enzyme blocking mechanism

A new model to study the role of arachidonic acid in colon cancer pathophysiology

Science.gov (United States)

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

2016-01-01

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

Docosahexaenoic acid (DHA) supplementation in pregnancy differentially modulates arachidonic acid and DHA status across FADS genotypes in pregnancy.

Science.gov (United States)

Scholtz, S A; Kerling, E H; Shaddy, D J; Li, S; Thodosoff, J M; Colombo, J; Carlson, S E

2015-03-01

Some FADS alleles are associated with lower DHA and ARA status assessed by the relative amount of arachidonic acid (ARA) and docosahexaenoic acid (DHA) in plasma and red blood cell (RBC) phospholipids (PL). We determined two FADS single nucleotide polymorphisms (SNPs) in a cohort of pregnant women and examined the relationship of FADS1rs174533 and FADS2rs174575 to DHA and ARA status before and after supplementation with 600mg per day of DHA. The 205 pregnant women studied were randomly assigned to placebo (mixed soy and corn oil) (n=96) or 600mg algal DHA (n=109) in 3 capsules per day for the last two trimesters of pregnancy. Women homozygous for the minor allele of FADS1rs174533 (but not FADS2rs174575) had lower DHA and ARA status at baseline. At delivery, minor allele homozygotes of FADS1rs174533 in the placebo group had lower RBC-DHA compared to major-allele carriers (P=0.031), while in the DHA-supplemented group, all genotypes had higher DHA status compared to baseline (P=0.001) and status did not differ by genotype (P=0.941). Surprisingly, DHA but not the placebo decreased ARA status of minor allele homozygotes of both FADS SNPs but not major allele homozygotes at delivery. Any physiological effects of changing the DHA to ARA ratio by increasing DHA intake appears to be greater in minor allele homozygotes of some FADS SNPs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Combination Therapy of PPAR Ligands and Inhibitors of Arachidonic Acid in Lung Cancer

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Jordi Tauler

2008-01-01

Full Text Available Lung cancer is the leading cause of cancer death in the United States and five-year survival remains low. Numerous studies have shown that chronic inflammation may lead to progression of carcinogenesis. As a result of inflammatory stimulation, arachidonic acid (AA metabolism produces proliferation mediators through complex and dynamic interactions of the products of the LOX/COX enzymes. One important mediator in the activation of the AA pathways is the nuclear protein PPAR. Targeting LOX/COX enzymes and inducing activation of PPAR have resulted in significant reduction of cell growth in lung cancer cell lines. However, specific COX-inhibitors have been correlated with an increased cardiovascular risk. Clinical applications are still being explored with a novel generation of dual LOX/COX inhibitors. PPAR activation through synthetic ligands (TZDs has revealed a great mechanistic complexity since effects are produced through PPAR-dependent and -independent mechanisms. Furthermore, PPAR could also be involved in regulation of COX-2. Overexpression of PPAR has reported to play a role in control of invasion and differentiation. Exploring the function of PPAR, in this new context, may provide a better mechanistic model of its role in cancer and give an opportunity to design a more efficient therapeutic approach in combination with LOX/COX inhibitors.

The TIP30 protein complex, arachidonic acid and coenzyme A are required for vesicle membrane fusion.

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Chengliang Zhang

Full Text Available Efficient membrane fusion has been successfully mimicked in vitro using artificial membranes and a number of cellular proteins that are currently known to participate in membrane fusion. However, these proteins are not sufficient to promote efficient fusion between biological membranes, indicating that critical fusogenic factors remain unidentified. We have recently identified a TIP30 protein complex containing TIP30, acyl-CoA synthetase long-chain family member 4 (ACSL4 and Endophilin B1 (Endo B1 that promotes the fusion of endocytic vesicles with Rab5a vesicles, which transport endosomal acidification enzymes vacuolar (H⁺-ATPases (V-ATPases to the early endosomes in vivo. Here, we demonstrate that the TIP30 protein complex facilitates the fusion of endocytic vesicles with Rab5a vesicles in vitro. Fusion of the two vesicles also depends on arachidonic acid, coenzyme A and the synthesis of arachidonyl-CoA by ACSL4. Moreover, the TIP30 complex is able to transfer arachidonyl groups onto phosphatidic acid (PA, producing a new lipid species that is capable of inducing close contact between membranes. Together, our data suggest that the TIP30 complex facilitates biological membrane fusion through modification of PA on membranes.

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

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

Science.gov (United States)

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

2010-01-01

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

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

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Fernando Norambuena

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

Maternal dietary n-6 polyunsaturated fatty acid deprivation does not exacerbate post-weaning reductions in arachidonic acid and its mediators in the mouse hippocampus.

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Alashmali, Shoug M; Kitson, Alex P; Lin, Lin; Lacombe, R J Scott; Bazinet, Richard P

2017-09-13

The present study examines how lowering maternal dietary n-6 polyunsaturated fatty acids (PUFA) (starting from pregnancy) compared to offspring (starting from post-weaning) affect the levels of n-6 and n-3 fatty acids in phospholipids (PL) and lipid mediators in the hippocampus of mice. Pregnant mice were randomly assigned to consume either a deprived or an adequate n-6 PUFA diet during pregnancy and lactation (maternal exposure). On postnatal day (PND) 21, half of the male pups were weaned onto the same diet as their dams, and the other half were switched to the other diet for 9 weeks (offspring exposure). At PND 84, upon head-focused high-energy microwave irradiation, hippocampi were collected for PL fatty acid and lipid mediator analyses. Arachidonic acid (ARA) concentrations were significantly decreased in both total PL and PL fractions, while eicosapentaenoic acid (EPA) concentrations were increased only in PL fractions upon n-6 PUFA deprivation of offspring, regardless of maternal exposure. Several ARA-derived eicosanoids were reduced, while some of the EPA-derived eicosanoids were elevated by n-6 PUFA deprivation in offspring. There was no effect of diet on docosahexaenoic acid (DHA) or DHA-derived docosanoids concentrations under either maternal or offspring exposure. These results indicate that the maternal exposure to dietary n-6 PUFA may not be as important as the offspring exposure in regulating hippocampal ARA and some lipid mediators. Results from this study will be helpful in the design of experiments aimed at testing the significance of altering brain ARA levels over different stages of life.

Cross-validated stable-isotope dilution GC-MS and LC-MS/MS assays for monoacylglycerol lipase (MAGL) activity by measuring arachidonic acid released from the endocannabinoid 2-arachidonoyl glycerol.

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Kayacelebi, Arslan Arinc; Schauerte, Celina; Kling, Katharina; Herbers, Jan; Beckmann, Bibiana; Engeli, Stefan; Jordan, Jens; Zoerner, Alexander A; Tsikas, Dimitrios

2017-03-15

2-Arachidonoyl glycerol (2AG) is an endocannabinoid that activates cannabinoid (CB) receptors CB1 and CB2. Monoacylglycerol lipase (MAGL) inactivates 2AG through hydrolysis to arachidonic acid (AA) and glycerol, thus modulating the activity at CB receptors. In the brain, AA released from 2AG by the action of MAGL serves as a substrate for cyclooxygenases which produce pro-inflammatory prostaglandins. Here we report stable-isotope GC-MS and LC-MS/MS assays for the reliable measurement of MAGL activity. The assays utilize deuterium-labeled 2AG (d 8 -2AG; 10μM) as the MAGL substrate and measure deuterium-labeled AA (d 8 -AA; range 0-1μM) as the MAGL product. Unlabelled AA (d 0 -AA, 1μM) serves as the internal standard. d 8 -AA and d 0 -AA are extracted from the aqueous buffered incubation mixtures by ethyl acetate. Upon solvent evaporation the residue is reconstituted in the mobile phase prior to LC-MS/MS analysis or in anhydrous acetonitrile for GC-MS analysis. LC-MS/MS analysis is performed in the negative electrospray ionization mode by selected-reaction monitoring the mass transitions [M-H] - →[M-H - CO 2 ] - , i.e., m/z 311→m/z 267 for d 8 -AA and m/z 303→m/z 259 for d 0 -AA. Prior to GC-MS analysis d 8 -AA and d 0 -AA were converted to their pentafluorobenzyl (PFB) esters by means of PFB-Br. GC-MS analysis is performed in the electron-capture negative-ion chemical ionization mode by selected-ion monitoring the ions [M-PFB] - , i.e., m/z 311 for d 8 -AA and m/z 303 for d 0 -AA. The GC-MS and LC-MS/MS assays were cross-validated. Linear regression analysis between the concentration (range, 0-1μM) of d 8 -AA measured by LC-MS/MS (y) and that by GC-MS (x) revealed a straight line (r 2 =0.9848) with the regression equation y=0.003+0.898x, indicating a good agreement. In dog liver, we detected MAGL activity that was inhibitable by the MAGL inhibitor JZL-184. Exogenous eicosatetraynoic acid is suitable as internal standard for the quantitative determination

Fenspiride inhibits histamine-induced responses in a lung epithelial cell line.

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Quartulli, F; Pinelli, E; Broué-Chabbert, A; Gossart, S; Girard, V; Pipy, B

1998-05-08

Using the human lung epithelial WI26VA4 cell line, we investigated the capacity of fenspiride, an anti-inflammatory drug with anti-bronchoconstrictor properties, to interfere with histamine-induced intracellular Ca2+ increase and eicosanoid formation. Histamine and a histamine H1 receptor agonist elicited a rapid and transient intracellular Ca2+ increase (0-60 s) in fluo 3-loaded WI26VA4 cells. This response was antagonized by the histamine H1 receptor antagonist, diphenhydramine, the histamine H2 receptor antagonist, cimetidine, having no effect. Fenspiride (10(-7)-10(-5) M) inhibited the histamine H1 receptor-induced Ca2+ increase. In addition, histamine induced a biphasic increase in arachidonic acid release. The initial rise (0-30 s), a rapid and transient arachidonic acid release, was responsible for the histamine-induced intracellular Ca2+ increase. In the second phase release (15-60 min), a sustained arachidonic acid release appeared to be associated with the formation of cyclooxygenase and lipoxygenase metabolites. Fenspiride (10(-5) M) abolished both phases of histamine-induced arachidonic acid release. These results suggest that anti-inflammatory and antibronchoconstrictor properties of fenspiride may result from the inhibition of these effects of histamine.

Effects of sexually dimorphic growth hormone secretory patterns on arachidonic acid metabolizing enzymes in rodent heart

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Zhang, Furong; Yu, Xuming [Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); He, Chunyan [Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Ouyang, Xiufang; Wu, Jinhua; Li, Jie; Zhang, Junjie; Duan, Xuejiao [Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Wan, Yu [Department of Physiology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Yue, Jiang, E-mail: yuejiang@whu.edu.cn [Department of Pharmacology, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China)

2015-12-15

The arachidonic acid (AA) metabolizing enzymes are the potential therapeutic targets of cardiovascular diseases (CVDs). As sex differences have been shown in the risk and outcome of CVDs, we investigated the regulation of heart AA metabolizing enzymes (COXs, LOXs, and CYPs) by sex-dependent growth hormone (GH) secretory patterns. The pulsatile (masculine) GH secretion at a physiological concentration decreased CYP1A1 and CYP2J3 mRNA levels more efficiently in the H9c2 cells compared with the constant (feminine) GH secretion; however, CYP1B1 mRNA levels were higher following the pulsatile GH secretion. Sex differences in CYP1A1, CYP1B1, and CYP2J11 mRNA levels were observed in both the wild-type and GHR deficient mice. No sex differences in the mRNA levels of COXs, LOXs, or CYP2E1 were observed in the wild-type mice. The constant GH infusion induced heart CYP1A1 and CYP2J11, and decreased CYP1B1 in the male C57/B6 mice constantly infused with GH (0.4 μg/h, 7 days). The activity of rat Cyp2j3 promoter was inhibited by the STAT5B protein, but was activated by C/EBPα (CEBPA). Compared with the constant GH administration, the levels of the nuclear phosphorylated STAT5B protein and its binding to the rat Cyp2j3 promoter were higher following the pulsatile GH administration. The constant GH infusion decreased the binding of the nuclear phosphorylated STAT5B protein to the mouse Cyp2j11 promoter. The data suggest the sexually dimorphic transcription of heart AA metabolizing enzymes, which might alter the risk and outcome of CVDs. GHR-STAT5B signal transduction pathway may be involved in the sex difference in heart CYP2J levels. - Highlights: • The transcription of heart Cyp1a1, Cyp1b1 and Cyp2j genes is sexually dimorphic. • There are no sex differences in the mRNA levels of heart COXs, LOXs, or CYP2E1. • GHR-STAT5B pathway is involved in sexually dimorphic transcription of heart Cpy2j genes. • Heart CYPs-mediated metabolism pathway of arachidonic acid may be sex

Effects of sexually dimorphic growth hormone secretory patterns on arachidonic acid metabolizing enzymes in rodent heart

International Nuclear Information System (INIS)

Zhang, Furong; Yu, Xuming; He, Chunyan; Ouyang, Xiufang; Wu, Jinhua; Li, Jie; Zhang, Junjie; Duan, Xuejiao; Wan, Yu; Yue, Jiang

2015-01-01

The arachidonic acid (AA) metabolizing enzymes are the potential therapeutic targets of cardiovascular diseases (CVDs). As sex differences have been shown in the risk and outcome of CVDs, we investigated the regulation of heart AA metabolizing enzymes (COXs, LOXs, and CYPs) by sex-dependent growth hormone (GH) secretory patterns. The pulsatile (masculine) GH secretion at a physiological concentration decreased CYP1A1 and CYP2J3 mRNA levels more efficiently in the H9c2 cells compared with the constant (feminine) GH secretion; however, CYP1B1 mRNA levels were higher following the pulsatile GH secretion. Sex differences in CYP1A1, CYP1B1, and CYP2J11 mRNA levels were observed in both the wild-type and GHR deficient mice. No sex differences in the mRNA levels of COXs, LOXs, or CYP2E1 were observed in the wild-type mice. The constant GH infusion induced heart CYP1A1 and CYP2J11, and decreased CYP1B1 in the male C57/B6 mice constantly infused with GH (0.4 μg/h, 7 days). The activity of rat Cyp2j3 promoter was inhibited by the STAT5B protein, but was activated by C/EBPα (CEBPA). Compared with the constant GH administration, the levels of the nuclear phosphorylated STAT5B protein and its binding to the rat Cyp2j3 promoter were higher following the pulsatile GH administration. The constant GH infusion decreased the binding of the nuclear phosphorylated STAT5B protein to the mouse Cyp2j11 promoter. The data suggest the sexually dimorphic transcription of heart AA metabolizing enzymes, which might alter the risk and outcome of CVDs. GHR-STAT5B signal transduction pathway may be involved in the sex difference in heart CYP2J levels. - Highlights: • The transcription of heart Cyp1a1, Cyp1b1 and Cyp2j genes is sexually dimorphic. • There are no sex differences in the mRNA levels of heart COXs, LOXs, or CYP2E1. • GHR-STAT5B pathway is involved in sexually dimorphic transcription of heart Cpy2j genes. • Heart CYPs-mediated metabolism pathway of arachidonic acid may be sex

Fluoride release from fluoride varnishes under acidic conditions.

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Lippert, F

2014-01-01

The aim was to investigate the in vitro fluoride release from fluoride varnishes under acidic conditions. Poly(methyl methacrylate) blocks (Perspex, n=3 per group) were painted with 80 ± 5 mg fluoride varnish (n=10) and placed into artificial saliva for 30 min. Then, blocks were placed into either 1% citric acid (pH 2.27) or 0.3% citric acid (pH 3.75) solutions (n=3 per solution and varnish) for 30 min with the solutions being replaced every 5 min. Saliva and acid solutions were analyzed for fluoride content. Data were analyzed using three-way ANOVA (varnish, solution, time). The three-way interaction was significant (p>0.0001). Fluoride release and release patterns varied considerably between varnishes. Fluoride release in saliva varied by a factor of more than 10 between varnishes. Some varnishes (CavityShield, Nupro, ProFluorid, Vanish) showed higher fluoride release in saliva than during the first 5 min of acid exposure, whereas other varnishes (Acclean, Enamel-Pro, MI Varnish, Vella) showed the opposite behavior. There was little difference between acidic solutions. Fluoride release from fluoride varnishes varies considerably and also depends on the dissolution medium. Bearing in mind the limitations of laboratory research, the consumption of acidic drinks after fluoride varnish application should be avoided to optimize the benefit/risk ratio.

Arachidonic acid metabolism by bovine placental tissue during the last month of pregnancy

International Nuclear Information System (INIS)

Hoedemaker, M.; Weston, P.G.; Wagner, W.C.

1991-01-01

Conversion of tritiated arachidonic acid (AA) into metabolites of the cyclo- and lipoxygenase pathways by bovine fetal placental tissue (200 mg) and fetal plus maternal placental tissue (400 mg) of Days 255, 265, 275 of gestation and at parturition (n = 5) during a 30 min incubation was measured using reverse-phase high pressure liquid chromatography. Fetal placental tissue produced 13,14-dihydro-15-keto-prostaglandin E2 (PGEM) as the major metabolite, the synthesis of which increased from Day 265 to Day 275 and parturition by 150% and 475%, respectively. In tissues collected at parturition, PGE2 synthesis was also detected. On Day 275 and at parturition fetal placental tissue synthesized the metabolite 12-hydroxyheptadecatrienoic acid (HHT), and throughout the experimental period the lipoxygenase product 15-HETE was detected with synthesis rates increasing over time of gestation. In addition, an unidentified metabolite was regularly found in the radiochromatograms which eluted at 1 h and 1 min (U101), between HHT and 15-HETE. The synthesis of this metabolite decreased as pregnancy progressed. Furthermore, various other polar and nonpolar metabolites pooled under the heading UNID were eluted, the production of which increased over time of gestation. The presence of maternal placental tissue did not influence the synthesis of PGEM, 15-HETE and U101, but the production of HHT was decreased when maternal tissue was present. Also, as pregnancy progressed, maternal placental tissue seemed to contribute to the pool of unidentified metabolites. In conclusion, fetal placental tissue seems to be the major source of the AA metabolites when compared with maternal placental tissue, and AA metabolism by bovine placental tissue is markedly increased throughout the last month of pregnancy, suggesting a role for AA metabolites in mechanisms controlling parturition

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

sphingolipids. These rats showed increased evaporation which was comparable to that of essential fatty acid-deficient rats. We interpret these results as strong evidence for a very specific and essential function of linoleic acid in maintaining the integrity of the epidermal water permeability barrier......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...

Arachidonic acid-and docosahexaenoic acid-enriched formulas modulate antigen-specific T cell responses to influenza virus in neonatal piglets.

Science.gov (United States)

Bassaganya-Riera, Josep; Guri, Amir J; Noble, Alexis M; Reynolds, Kathryn A; King, Jennifer; Wood, Cynthia M; Ashby, Michael; Rai, Deshanie; Hontecillas, Raquel

2007-03-01

Whereas the immunomodulatory effects of feeding either arachidonic acid (AA) or docosahexaenoic acid (DHA) separately have been previously investigated, little is known about the immunomodulatory efficacy of AA or DHA when they are fed in combination as infant formula ingredients. The objective of this study was to investigate the ability of AA- and DHA(AA/DHA)-enriched infant formula to modulate immune responses in the neonate in response to an inactivated influenza virus vaccine. Neonatal piglets (n = 48) were weaned on day 2 of age and distributed into 16 blocks of 3 littermate piglets each. Within each block, piglets were randomly assigned to a control formula, AA/DHA-enriched formula (0.63% AA and 0.34% DHA), or sow milk for 30 d. On day 9, 8 blocks of piglets were immunized with an inactivated influenza virus vaccine. On days 0, 9, 16, 23, and 30 after weaning, we measured influenza virus-specific T cell proliferation and phenotype of T subsets in peripheral blood. A delayed-type hypersensitivity reaction test was administered on day 28. Cytokine messenger RNA expression was determined by quantitative real time reverse transcriptase-polymerase chain reaction on day 30. The influenza virus-specific CD4(+) and CD8(+) T cell ex vivo lymphoproliferative responses were significantly lower on day 23 after immunization in piglets receiving dietary AA/DHA supplementation and sow milk than in those receiving the unsupplemented control formula. The immunomodulatory effects of AA/DHA-enriched formulas were consistent with up-regulation of interleukin 10 in peripheral blood mononuclear cells. Overall, it appears that the AA/DHA-enriched formula modulated antigen-specific T cell responses in part through an interleukin 10-dependent mechanism.

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

International Nuclear Information System (INIS)

Elattar, T.M.; Lin, H.S.; Tira, D.E.

1983-01-01

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 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

Novel Caffeic Acid Nanocarrier: Production, Characterization, and Release Modeling

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Milad Fathi

2013-01-01

Full Text Available This paper deals with the development of novel nanocarriers using layer by layer carbohydrate coating of caffeic acid loaded solid lipid nanoparticles (SLNs to improve stability and colon delivery of the poorly water-soluble caffeic acid. Three biopolymers (chitosan, alginate, and pectin in different concentrations (0.1, 0.25, and 0.5% were electrostatically coated over the SLN surface. The size and zeta potential of produced nanocarriers were measured using photon correlation spectroscopy. Mathematical models (i.e., zero-order, first-order, Higuchi, Ritger-Peppas, reciprocal powered time, Weibull, and quadratic models were used to describe the release and kinetic modeling in gastrointestinal solution (GIS. Also, antioxidant activity of caffeic acid during the release in GIS was investigated using DPPH and reducing activity methods. The prepared treatments coated by alginate-chitosan as well as pectin-chitosan coated SLN at the concentration of 0.1% showed nanosized bead; the latter efficiently retarded the release of caffeic acid in gastric media up to 2.5 times higher than that of SLN. Zeta potential values of coated samples were found to significantly increase in comparison to SLN indicating the higher stability of produced nanocarriers. Antioxidant activity of caffeic acid after gastric release did not result in the same trend as observed for caffeic acid release from different treatments; however, in line with less caffeic acid release in the intestine solution by the effect of coating, lower antioxidant activity was determined at the end stage of the experiment.

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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Devlin, Angela M.; Chau, Cecil M. Y.; Matheson, Julie; McCarthy, Deanna; Yurko-Mauro, Karin; Innis, Sheila M.; Grunau, Ruth E.

2017-01-01

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. PMID:28878181

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

Directory of Open Access Journals (Sweden)

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.

Glucocorticoid regulation of gonadotropin release from gonadotropes of ovine pituitary gland in vitro

International Nuclear Information System (INIS)

Nangalama, A.W.

1989-01-01

In order to understand the role of glucocorticoids in the regulation of gonadotropin release by the pituitary gland, the short-term effects of cortisol perifusion (1.5 h to 8 hrs) on GnRH-induced LH secretion were investigated. To determine the biochemical mechanism(s) by which cortisol can act to modulate GnRH-induced LH release, the interactions of cortisol and arachidonic acid in GnRH-stimulated LH release were examined. Cortisol perifusion for 1.5 hr had no effect on GnRH-induced LH release, but longer treatment periods (4 hr-8 hrs) significantly reduced GnRH-stimulated LH release (4.0 hr, p -4 M AA was administered for 20 min before a 10 min, 10 -10 M GnRH pulse. Like cortisol, chloroquine also failed to inhibit AA-induced LH release. Perifusion with 10 -6 M cortisol for 6.0 hours significantly (p 3 ]AA release 24% below the basal (100%) [ 3 H]AA secretion. Reduction of [ 3 H]AA release was accompanied by decreased GnRH-stimulated LH secretion

Alpha 1-adrenergic receptor-mediated phosphoinositide hydrolysis and prostaglandin E2 formation in Madin-Darby canine kidney cells. Possible parallel activation of phospholipase C and phospholipase A2

International Nuclear Information System (INIS)

Slivka, S.R.; Insel, P.A.

1987-01-01

alpha 1-Adrenergic receptors mediate two effects on phospholipid metabolism in Madin-Darby canine kidney (MDCK-D1) cells: hydrolysis of phosphoinositides and arachidonic acid release with generation of prostaglandin E2 (PGE2). The similarity in concentration dependence for the agonist (-)-epinephrine in eliciting these two responses implies that they are mediated by a single population of alpha 1-adrenergic receptors. However, we find that the kinetics of the two responses are quite different, PGE2 production occurring more rapidly and transiently than the hydrolysis of phosphoinositides. The antibiotic neomycin selectively decreases alpha 1-receptor-mediated phosphatidylinositol 4,5-bisphosphate hydrolysis without decreasing alpha 1-receptor-mediated arachidonic acid release and PGE2 generation. In addition, receptor-mediated inositol trisphosphate formation is independent of extracellular calcium, whereas release of labeled arachidonic acid is largely calcium-dependent. Moreover, based on studies obtained with labeled arachidonic acid, receptor-mediated generation of arachidonic acid cannot be accounted for by breakdown of phosphatidylinositol monophosphate, phosphatidylinositol bisphosphate, or phosphatidic acid. Further studies indicate that epinephrine produces changes in formation or turnover of several classes of membrane phospholipids in MDCK cells. We conclude that alpha 1-adrenergic receptors in MDCK cells appear to regulate phospholipid metabolism by the parallel activation of phospholipase C and phospholipase A2. This parallel activation of phospholipases contrasts with models described in other systems which imply sequential activation of phospholipase C and diacylglycerol lipase or phospholipase A2

A role for AMPK in the inhibition of glucose-6-phosphate dehydrogenase by polyunsaturated fatty acids

Energy Technology Data Exchange (ETDEWEB)

Kohan, Alison B.; Talukdar, Indrani; Walsh, Callee M. [Department of Biochemistry, West Virginia University, Morgantown, WV (United States); Salati, Lisa M., E-mail: lsalati@hsc.wvu.edu [Department of Biochemistry, West Virginia University, Morgantown, WV (United States)

2009-10-09

Both polyunsaturated fatty acids and AMPK promote energy partitioning away from energy consuming processes, such as fatty acid synthesis, towards energy generating processes, such as {beta}-oxidation. In this report, we demonstrate that arachidonic acid activates AMPK in primary rat hepatocytes, and that this effect is p38 MAPK-dependent. Activation of AMPK mimics the inhibition by arachidonic acid of the insulin-mediated induction of G6PD. Similar to intracellular signaling by arachidonic acid, AMPK decreases insulin signal transduction, increasing Ser{sup 307} phosphorylation of IRS-1 and a subsequent decrease in AKT phosphorylation. Overexpression of dominant-negative AMPK abolishes the effect of arachidonic acid on G6PD expression. These data suggest a role for AMPK in the inhibition of G6PD by polyunsaturated fatty acids.

Polyunsaturated fatty acids and their metabolites in brain function and disease.

Science.gov (United States)

Bazinet, Richard P; Layé, Sophie

2014-12-01

The brain is highly enriched with fatty acids. These include the polyunsaturated fatty acids (PUFAs) arachidonic acid and docosahexaenoic acid, which are largely esterified to the phospholipid cell membrane. Once PUFAs are released from the membrane, they can participate in signal transduction, either directly or after enzymatic conversion to a variety of bioactive derivatives ('mediators'). PUFAs and their mediators regulate several processes within the brain, such as neurotransmission, cell survival and neuroinflammation, and thereby mood and cognition. PUFA levels and the signalling pathways that they regulate are altered in various neurological disorders, including Alzheimer's disease and major depression. Diet and drugs targeting PUFAs may lead to novel therapeutic approaches for the prevention and treatment of brain disorders.

Gingival tissue-produced inhibition of platelet aggregation and the loss of inhibition in streptozotocin-induced diabetic rats

Energy Technology Data Exchange (ETDEWEB)

Kawamura, Keiichiroh; Tamai, Kazuharu; Shirakawa, Masaharu; Okamoto, Hiroshi; Dohi, Toshihiro; Tsujimoto, Akira

1988-01-01

Addition of medium incubated with normal rat gingival tissue to platelet-rich plasma inhibited ADP-induced platelet aggregation. The ability of rat gingiva to produce activity inhibiting platelet aggregation was enhanced by the addition of arachidonic acid. Diabetic rat gingiva failed to inhibit platelet aggregation but did produce the anti-platelet aggregating activity in the presence of arachidonic acid. Indomethacin blocked the production of anti-platelet aggregating activity. There was no difference in conversion of (1-/sup 14/C)arachidonic acid to prostaglandins by normal and diabetic rat gingiva. These results suggest that an arachidonic acid metabolite released from gingiva during incubation inhibits platelet aggregation, and the synthesis of the metabolite is impaired in diabetic rat gingiva. A decrease in availability of arachidonic acid may be a causal factor of the defect in diabetic rat gingiva.

Gingival tissue-produced inhibition of platelet aggregation and the loss of inhibition in streptozotocin-induced diabetic rats

International Nuclear Information System (INIS)

Kawamura, Keiichiroh; Tamai, Kazuharu; Shirakawa, Masaharu; Okamoto, Hiroshi; Dohi, Toshihiro; Tsujimoto, Akira

1988-01-01

Addition of medium incubated with normal rat gingival tissue to platelet-rich plasma inhibited ADP-induced platelet aggregation. The ability of rat gingiva to produce activity inhibiting platelet aggregation was enhanced by the addition of arachidonic acid. Diabetic rat gingiva failed to inhibit platelet aggregation but did produce the anti-platelet aggregating activity in the presence of arachidonic acid. Indomethacin blocked the production of anti-platelet aggregating activity. There was no difference in conversion of [1- 14 C]arachidonic acid to prostaglandins by normal and diabetic rat gingiva. These results suggest that an arachidonic acid metabolite released from gingiva during incubation inhibits platelet aggregation, and the synthesis of the metabolite is impaired in diabetic rat gingiva. A decrease in availability of arachidonic acid may be a causal factor of the defect in diabetic rat gingiva. (author)

Platelet Arachidonic Acid Deficiency May Contribute to Abnormal Platelet Function During Parenteral Fish Oil Monotherapy in a Piglet Model.

Science.gov (United States)

Turner, Justine M; Field, Catherine J; Goruk, Sue; Wizzard, Pamela; Dicken, Bryan J; Bruce, Aisha; Wales, Paul W

2016-05-01

Fish oil monotherapy has been an advance for treating intestinal failure-associated liver disease (IFALD). However, such patients are at risk of bleeding complications from liver disease and because fish oil can inhibit thrombosis. We have previously reported abnormal platelet function in neonatal piglets given fish oil monotherapy during parenteral nutrition (PN). The purpose of this study was to determine if abnormal fatty acid composition of the platelets could explain the prior observed antiplatelet effect. Neonatal piglets were assigned to 2 treatments: PN with fish oil monotherapy (FO; n = 4) or PN with soy oil (SO; n = 5). On day 14, plasma was collected and platelets isolated by centrifuging. The fatty acid content in plasma and platelet plug were measured using gas liquid chromatography and compared with controls (CON; n = 5). The arachidonic acid (AA) content in the FO group was on average half that of the SO group, in both the platelets (FO, 3.5% vs SO, 7.6%; P = .021; CON, 4.5%-11%) and the plasma (FO, 3.8% vs SO, 9.2%; P = .002; CON, 6.1%-9.5%). No bleeding complications were observed for any piglets during PN treatment. Using platelet mapping, we have previously shown that neonatal piglets given fish oil monotherapy have abnormal platelet function in the AA pathway. This report demonstrates that such an abnormality can be explained by platelet AA deficiency. Platelet mapping and platelet fatty acid analysis should be undertaken in human infants treated with fish oil monotherapy during PN. © 2015 American Society for Parenteral and Enteral Nutrition.

Prostacyclin production in rabbit arteries in situ: inhibition by arachidonic acid-induced endothelial cell damage or by low-dose aspirin.

Science.gov (United States)

Ingerman-Wojenski, C; Silver, M J; Smith, J B; Nissenbaum, M; Sedar, A W

1981-04-01

The central artery of the rabbit ear was perfused in situ and effluent fractions from the artery were assayed for 6-keto-prostaglandin F1 alpha (6-K-PGF1 alpha) and thromboxane B2 (TxB2), the stable metabolites of prostacyclin (PGI2) and TxA2, using specific radioimmunoassays. These metabolites of arachidonic acid (AA) were not detected in the effluent during infusion of Tyrode's solution but both metabolites were detected when small amounts of AA were infused into the artery. Examination of the arteries by scanning electron microscopy revealed that high concentrations of AA which caused a short burst of 6-K-PGF1 alpha and TxB2 production damaged the endothelial cells while lower concentrations which stimulated continuous production did not cause damage. When a non-damaging concentration of AA was infused into an artery that had previously received a damaging concentration, PG production was greatly reduced. Pretreatment of the rabbits with 4 mg/kg acetyl-salicylic acid (ASA) inhibited 6-K-PGF1 alpha production by the rabbit ear artery in response to AA and 70% inhibition was still evident 18 hours after ASA.

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.

Valnoctamide, which reduces rat brain arachidonic acid turnover, is a potential non-teratogenic valproate substitute to treat bipolar disorder.

Science.gov (United States)

Modi, Hiren R; Ma, Kaizong; Chang, Lisa; Chen, Mei; Rapoport, Stanley I

2017-08-01

Valproic acid (VPA), used for treating bipolar disorder (BD), is teratogenic by inhibiting histone deacetylase. In unanaesthetized rats, chronic VPA, like other mood stabilizers, reduces arachidonic acid (AA) turnover in brain phospholipids, and inhibits AA activation to AA-CoA by recombinant acyl-CoA synthetase-4 (Acsl-4) in vitro. Valnoctamide (VCD), a non-teratogenic constitutional isomer of VPA amide, reported effective in BD, also inhibits recombinant Acsl-4 in vitro. VCD like VPA will reduce brain AA turnover in unanaesthetized rats. A therapeutically relevant (50mg/kg i.p.) dose of VCD or vehicle was administered daily for 30 days to male rats. AA turnover and related parameters were determined using our kinetic model, following intravenous [1- 14 C]AA in unanaesthetized rats for 10min, and measuring labeled and unlabeled lipids in plasma and high-energy microwaved brain. VCD, compared with vehicle, increased λ, the ratio of brain AA-CoA to unesterified plasma AA specific activities; and decreased turnover of AA in individual and total brain phospholipids. VCD's ability like VPA to reduce rat brain AA turnover and inhibit recombinant Acsl-4, and its efficacy in BD, suggest that VCD be further considered as a non-teratogenic VPA substitute for treating BD. Published by Elsevier B.V.

Arachidonic acid-induced Ca2+ entry and migration in a neuroendocrine cancer cell line.

Science.gov (United States)

Goswamee, Priyodarshan; Pounardjian, Tamar; Giovannucci, David R

2018-01-01

Store-operated Ca 2+ entry (SOCE) has been implicated in the migration of some cancer cell lines. The canonical SOCE is defined as the Ca 2+ entry that occurs in response to near-maximal depletion of Ca 2+ within the endoplasmic reticulum. Alternatively, arachidonic acid (AA) has been shown to induce Ca 2+ entry in a store-independent manner through Orai1/Orai3 hetero-multimeric channels. However, the role of this AA-induced Ca 2+ entry pathway in cancer cell migration has not been adequately assessed. The present study investigated the involvement of AA-induced Ca 2+ entry in migration in BON cells, a model gastro-enteropancreatic neuroendocrine tumor (GEPNET) cell line using pharmacological and gene knockdown methods in combination with live cell fluorescence imaging and standard migration assays. We showed that both the store-dependent and AA-induced Ca 2+ entry modes could be selectively activated and that exogenous administration of AA resulted in Ca 2+ entry that was pharmacologically distinct from SOCE. Also, whereas homomeric Orai1-containing channels appeared to largely underlie SOCE, the AA-induced Ca 2+ entry channel required the expression of Orai3 as well as Orai1. Moreover, we showed that AA treatment enhanced the migration of BON cells and that this migration could be abrogated by selective inhibition of the AA-induced Ca 2+ entry. Taken together, these data revealed that an alternative Orai3-dependent Ca 2+ entry pathway is an important signal for GEPNET cell migration.

Kupffer cell depletion attenuates leptin-mediated methoxamine-stimulated portal perfusion pressure and thromboxane A2 release in a rodent model of NASH-cirrhosis.

Science.gov (United States)

Yang, Ying-Ying; Huang, Yi-Tsau; Tsai, Tung-Hu; Hou, Ming-Chih; Lee, Fa-Yauh; Lee, Shou-Dong; Lin, Han-Chieh

2012-12-01

Cirrhotic portal hypertension is characterized by increased hepatic oxidative stress, AA (arachidonic acid)-derived TXA(2) (thromboxane A(2)) release and exaggerated hepatic response to the α-adrenergic agonist MTX (methoxamine). Besides promoting hepatic fibrosis, the role of hyperleptinaemia in the modulation of vascular response in NASH (non-alcoholic steatohepatitis) rat livers remains unknown. The aim of the present study was to explore the possible links between hyperleptinaemia and the disarrangement in the hepatic microcirculation. NASH-cirrhosis with hyperleptinaemia was induced in lean rats by feeding with an HF/MCD (high-fat/methionine-choline-deficient) diet. Portal haemodynamics, various substances, protein and mRNA expression and PUFA (polyunsaturated fatty acid) composition were measured. Finally, the effects of leptin pre-infusion on TXA(2) release and concentration-PPP (portal perfusion pressure) curves in response to MTX were evaluated by simultaneously pre-treatment with the Kupffer cell inactivators GdCl(3) (gadolinium chloride) or EC (encapsulated clodronate), the TXS (TXA(2) synthase) inhibitor furegrelate, the TP receptor (TXA(2) receptor) antagonist SQ29548 and the dual TXS/TP receptor antagonist BM567. In HF/MCD+leptin-lean rats, cirrhosis-induced PPP and MTX hyper-responsiveness were associated with increased hepatic TXA(2) production, TBARS (thiobarbituric acid-reacting substances) levels and the AA (arachidonic acid)/n-3 PUFA ratio, and up-regulation of hepatic leptin, FAS (fatty acid synthase), NADPH oxidase subunits, TXS, TP receptor, TGFβ(1) (transforming growth factor β(1)) proteins and mRNAs. Pre-infusion of leptin significantly enhanced MTX-stimulated PPP elevation and TXA(2) release, which were attenuated by GdCl(3) and EC pre-treatment. Concomitantly pre-incubation with BM567, but not furegrelate or SQ29548, significantly abolished the leptin-enhanced MTX-stimulated increase in PPP in NASH-cirrhotic rats. Hyperleptinaemia

Effect of extracellular fatty acids on lipid metabolism in cultured rabbit articular chondrocytes

International Nuclear Information System (INIS)

Nagao, M.; Ishii, S.; Murata, Y.; Akino, T.

1991-01-01

Rabbit articular chondrocytes were cultured for 8 h in the presence of various concentrations (5-500 microM) of 14 C oleic, 14 C linoleic, and 3H arachidonic acids. The radioactive unsaturated fatty acids were incorporated into triacylglycerol (TG) and phosphatidylcholine (PC) in a concentration-dependent manner; more fatty acids were incorporated into TG than into PC, at higher concentrations of extracellular fatty acids. Among these fatty acids, arachidonic acid was incorporated into TG much more than into PC, in spite of a very low concentration of arachidonic acid in TG. After transfer of the labeled cells to maintenance medium, the radioactivity in TG declined rapidly and 3 H arachidonic acid radioactivity in PC increased continuously during the chase time periods. Palmitoyl-unsaturated species were mainly formed in PC when cultured at a concentration of 5 microM of each fatty acid. However, when cultured at 500 microM, unsaturated-unsaturated species, specific for each unsaturated fatty acid were actively formed. These findings indicate that (1) fatty acid composition of TG and PC in articular chondrocytes is influenced by the degree of fatty acid supply, (2) formation and turnover of TG plays a role in fatty acid metabolism of cells, and (3) fatty acid pairing in PC is modulated by extracellular fatty acid concentrations

Effects of carnitine and its congeners on eicosanoid discharge from rat cells: implications for release of TNFα

Directory of Open Access Journals (Sweden)

Ingrid M. Garrelds

1993-01-01

Full Text Available THE acyl carrier coenzyme A (CoA is involved in fatty acid metabolism. The carnitine/CoA ratio is of particular importance in regulating the transport of long-chain fatty acids into mitochondria for oxidation. Also CoA has a role in the formation and breakdown of products from both the cyclooxygenase and lipoxygenase pathways of the precursor arachidonic acid. In the present study the effect of 4 days feeding of 300 mg/kg/day of L-carnitine, acetyl Lcarnitine and propionyl L-carnitine on the basal and calcium ionophore (A23187 stimulated release of arachidonic acid metabolites from rat carrageenin elicited peritoneal cells was investigated. There were two series of experiments carried out. In the first, the harvested peritoneal cell population consisted of less than 90% macrophages and additional polymorphonuclear (PMN leucocytes. The basal release of prostaglandin E2 (PGE2, 6-ketoprostaglandin F1α (6-keto-PGF1α and leukotriene B4 (LTB4 was stimulated by all treatments. The A23187 stimulated release of 6-keto-PGF1α and LTB4 was increased by all three compounds. The 6-keto-PGF1α:TxB2 and 6-keto-PGF1α:LTB4 ratios were increased by carnitine treatment. These results suggested that carnitine could modify the macrophage component of an inflammatory site in vivo. In the second series of experiments the harvested cell population was highly purified (>95% macrophages and none of the compounds fed to the rats caused a change of either eicosanoid or TNFα formation. Moreover the 6-keto-PGF1α:TxB2 and 6-keto-PGF1α:LTB4 ratios were not enhanced by any of the compounds tested. It is conceivable that in the first series the increased ratios 6-keto-PGF1α:TxB2 and 6-keto-PGF1α:LTB4 reflected the effect of carnitine or its congeners on PMN leucocytes rather than on macrophages.

Changes in cholesterol content and fatty acid composition of serum lipid in irradiated rat

International Nuclear Information System (INIS)

Ohashi, Shigeru

1979-01-01

The effect of a single dose of whole body irradiation on the serum cholesterol content and fatty acid composition of serum lipids in rats was investigated. A change in the fatty acid composition of liver lipids was also observed. After 600 rad of irradiation, the cholesterol content increased, reached a maximum 3 days after irradiation, and then decreased. After irradiation, an increase in cholesterol content and a marked decrease in triglyceride content were observed, bringing about a change in the amount of total serum lipids. The fatty acid compositions of normal and irradiated rat sera were compared. The relative percentages of palmitic and oleic acids in total lipids decreased while those of stearic and arachidonic acids increased. Serum triglyceride had trace amounts of arachidonic acid and the unsaturated fatty acid component decreased after irradiation. On the other hand, unsaturated fatty acid in cholesterol ester increased after irradiation, while linoleic and arachidonic acids made up 29% and 22% in the controls and 17% and 61% after irradiation, respectively. The fatty acid composition of total liver lipids after irradiation showed a decrease in palmitic and oleic acids and an increase in stearic and arachidonic acids, the same trend as observed in serum lipid fatty acid. Liver cholesterol ester showed trace amounts of linoleic and arachidonic acids and an increase in short-chain fatty acid after irradiation. The major component of serum phospholipids was phosphatidylcholine while palmitostearyl lecithine and unsaturated fatty acid were minor components. Moreover, phosphatidylcholine and phosphatidylethanolamine were the major components of liver phospholipids, having highly unsaturated fatty acids. The changes in fatty acid composition were similar to the changes in total phospholipids. (J.P.N.)

Bifidobacterium breve with α-linolenic acid and linoleic acid alters fatty acid metabolism in the maternal separation model of irritable bowel syndrome.

Science.gov (United States)

Barrett, Eoin; Fitzgerald, Patrick; Dinan, Timothy G; Cryan, John F; Ross, R Paul; Quigley, Eamonn M; Shanahan, Fergus; Kiely, Barry; Fitzgerald, Gerald F; O'Toole, Paul W; Stanton, Catherine

2012-01-01

The aim of this study was to compare the impact of dietary supplementation with a Bifidobacterium breve strain together with linoleic acid & α-linolenic acid, for 7 weeks, on colonic sensitivity and fatty acid metabolism in rats. Maternally separated and non-maternally separated Sprague Dawley rats (n = 15) were orally gavaged with either B. breve DPC6330 (10(9) microorganisms/day) alone or in combination with 0.5% (w/w) linoleic acid & 0.5% (w/w) α-linolenic acid, daily for 7 weeks and compared with trehalose and bovine serum albumin. Tissue fatty acid composition was assessed by gas-liquid chromatography and visceral hypersensitivity was assessed by colorectal distension. Significant differences in the fatty acid profiles of the non-separated controls and maternally separated controls were observed for α-linolenic acid and arachidonic acid in the liver, oleic acid and eicosenoic acid (c11) in adipose tissue, and for palmitoleic acid and docosahexaenoic acid in serum (pbreve DPC6330 to MS rats significantly increased palmitoleic acid, arachidonic acid and docosahexaenoic acid in the liver, eicosenoic acid (c11) in adipose tissue and palmitoleic acid in the prefrontal cortex (pbreve DPC6330 to non separated rats significantly increased eicosapentaenoic acid and docosapentaenoic acid in serum (pbreve DPC6330 in combination with linoleic acid and α-linolenic acid to maternally separated rats significantly increased docosapentaenoic acid in the serum (pbreve DPC6330 with fatty acid supplementation to non-separated rats significantly increased liver and serum docosapentaenoic acid (pbreve DPC6330 influenced host fatty acid metabolism. Administration of B. breve DPC6330 to maternally separated rats significantly modified the palmitoleic acid, arachidonic acid and docosahexaenoic acid contents in tissues. The effect was not observed in non-separated animals.

Ethyl cellulose microcapsules for protecting and controlled release of folic acid.

Science.gov (United States)

Prasertmanakit, Satit; Praphairaksit, Nalena; Chiangthong, Worawadee; Muangsin, Nongnuj

2009-01-01

Ethyl cellulose microcapsules were developed for use as a drug-delivery device for protecting folic acid from release and degradation in the undesirable environmental conditions of the stomach, whilst allowing its release in the intestinal tract to make it available for absorption. The controlled release folic acid-loaded ethyl cellulose microcapsules were prepared by oil-in-oil emulsion solvent evaporation using a mixed solvent system, consisting of a 9:1 (v/v) ratio of acetone:methanol and light liquid paraffin as the dispersed and continuous phase. Span 80 was used as the surfactant to stabilize the emulsion. Scanning electron microscopy revealed that the microcapsules had a spherical shape. However, the particulate properties and in vitro release profile depended on the concentrations of the ethyl cellulose, Span 80 emulsifier, sucrose (pore inducer), and folic acid. The average diameter of the microcapsules increased from 300 to 448 microm, whilst the folic acid release rate decreased from 52% to 40%, as the ethyl cellulose concentration was increased from 2.5% to 7.5% (w/v). Increasing the Span 80 concentration from 1% to 4% (v/v) decreased the average diameter of microcapsules from 300 to 141 microm and increased the folic acid release rate from 52% to 79%. The addition of 2.5-7.5% (w/v) of sucrose improved the folic acid release from the microcapsules. The entrapment efficiency was improved from 64% to 88% when the initial folic acid concentration was increased from 1 to 3 mg/ml.

Biotransformation of arachidonic acid (AA) and eicosapentaenoic acid (EPA) into lipoxins and lipoxenes by porcine leukocytes

International Nuclear Information System (INIS)

Wong, P.Y.K.; Spur, B.; Hirai, A.; Yoshida, S.; Tamura, Y.; Lam, B.K.

1986-01-01

Lipoxins and lipoxenes have been reported to be formed after incubation of 15-hydroperoxyeicosatetraenoic acid and 15-hydroperoxyeicosapentaenoic acid with human leukocytes and porcine leukocytes, respectively. The authors examined the ability of porcine leukocytes to metabolize [ 14 C]-AA and [ 14 C]-EPA (100 μM) to lipoxins and lipoxenes. Incubation products were separated by RP-HPLC and identified by U.V. spectrum and GC/MS. Porcine leukocytes metabolized both AA and EPA to form lipoxins and lipoxenes in addition to mono- and di-hydroxyl fatty acids. Quantitative analysis from U.V. absorbance after RP-HPLC revealed that about 0.05% of AA was converted to lipoxins A and B and 0.1% of EPA was converted to lipoxenes A and B. In addition, treatment of leukotriene A 4 and leukotriene A 5 with 15-lipoxygenase also gave rise to several isomers of lipoxin and lipoxene. Thus, lipoxins and lipoxenes would have been derived from AA and EPA after dioxygenation by 5-lipoxygenase and 15-lipoxygenase, respectively. When tested for biological activity, lipoxene A (2 μM), like lipoxin A, induced superoxide anion generation in canine neutrophils but had no effect on lysosomal enzyme release on neutrophil aggregation

Influence of Citric Acid on the Metal Release of Stainless Steels

Energy Technology Data Exchange (ETDEWEB)

Mazinanian, N.; Wallinder, I. Odnevall; Hedberg, Y. S. [KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Chemistry, Division of Surface and Corrosion Science, Stockholm (Sweden)

2015-08-15

Knowledge of how metal releases from the stainless steels used in food processing applications and cooking utensils is essential within the framework of human health risk assessment. A new European standard test protocol for testing metal release in food contact materials made from metals and alloys has recently been published by the Council of Europe. The major difference from earlier test protocols is the use of citric acid as the worst-case food simulant. The objectives of this study were to assess the effect of citric acid at acidic, neutral, and alkaline solution pH on the extent of metal release for stainless steel grades AISI 304 and 316, commonly used as food contact materials. Both grades released lower amounts of metals than the specific release limits when they were tested according to test guidelines. The released amounts of metals were assessed by means of graphite furnace atomic absorption spectroscopy, and changes in the outermost surface composition were determined using X-ray photoelectron spectroscopy. The results demonstrate that both the pH and the complexation capacity of the solutions affected the extent of metal release from stainless steel and are discussed from a mechanistic perspective. The outermost surface oxide was significantly enriched in chromium upon exposure to citric acid, indicating rapid passivation by the acid. This study elucidates the effect of several possible mechanisms, including complex ion- and ligand-induced metal release, that govern the process of metal release from stainless steel under passive conditions in solutions that contain citric acid.

Anaphylatoxin C3a induced mediator release from mast cells

International Nuclear Information System (INIS)

Herrscher, R.; Hugli, T.E.; Sullivan, T.J.

1986-01-01

The authors investigated the biochemical and functional consequences of the binding of highly purified human C3a to isolated rat serosal mast cells. C3a caused a dose-dependent (1-30 μM), noncytotoxic release of up to 64% (+/- 7 SEM) of the mast cell histamine content. C3a (10μM) increased 45 Ca ++ uptake 8.2- fold (+/- 2.2 SEM) above unstimulated control values within 10 minutes. Arachidonyl-diacylglycerol and arachidonyl-monoacylglycerol levels increased significantly within 2 minutes after C3a (10 μM) stimulation. Turnover of phosphatidylinositol, phosphatidic acid, and phosphatidylcholine were increased within 15 minutes. In contrast to antigen, C3a stimulation (10 μM) was not enhanced by exogenous phosphatidylserine, and was not inhibited by ethanol (100 μmM). C3a suppressed arachidonic acid (AA) release to 38% (+/- 9 SEM) below baseline, and did not cause PGD 2 formation. C3a and the desarginine form of C3a caused identical responses in all experiments. These studies indicate that C3a stimulation activates mast cell preformed mediator release in a manner very similar to antigen-IgE stimulation, but C3a suppresses free AA levels and does not stimulate PGD 2 synthesis

Cell Swelling Activates Phospholipase A2 in Ehrlich Ascites Tumor Cells

DEFF Research Database (Denmark)

Thoroed, S.M.; Lauritzen, L.; Lambert, I.H.

1997-01-01

Ehrlich ascites tumor cells! loaded with H-labeled arachidonic acid and C-labeled stearic acid for two hours, were washed and transferred to either isotonic or hypotonic media containing BSA to scavenge the labeled fatty acids released from the cells. During the first two minutes of hypo......-osmotic exposure the rate of H-labeled arachidonic acid release is 3.3 times higher than that observed at normal osmolality. Cell swelling also causes an increase in the production of C-stearic acid-labeled lysophosphatidylcholine. This indicates that a phospholipase A is activated by cell swelling in the Ehrlich...... cells. Within the same time frame there is no swelling-induced increase in C-labeled stearic acid release nor in the synthesis of phosphatidyl C-butanol in the presence of C-butanol. Furthermore, U7312, an inhibitor of phospholipase C, does not affect the swelling induced release of C...

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

International Nuclear Information System (INIS)

Li, Ying; Zhao, Haixia; Wang, Yuzhong; Zheng, Hao; Yu, Wei; Chai, Hongyan; Zhang, Jing; Falck, John R.; Guo, Austin M.; Yue, Jiang; Peng, Renxiu; Yang, Jing

2013-01-01

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 2 (PGE 2 ) and 20-hydroxyeicosatetraenoic acid (20-HETE), without affecting COX-1, 5-lipoxygenase (5-LOX), 5-lipoxygenase activating protein (FLAP), and leukotriene B 4 (LTB 4 ). In addition, it downregulated the levels of phospho-PI3K, phospho-PDK (Ser 241 ), phospho-Akt (Thr 308 ), phospho-Bad (Ser 136 ), and Bcl-x L expression, thereby activating caspase cascades and eventually cleaving poly(ADP-ribose) polymerase (PARP). Conversely, the addition of exogenous eicosanoids, including PGE 2 , LTB 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 308 ). Collectively, these data suggest that isoliquiritigenin induces growth inhibition and apoptosis through downregulating AA metabolic network and the deactivation of PI3K/Akt in

The role of arachidonic acid metabolites in signal transduction in an identified neural network mediating presynaptic inhibition in Aplysia

International Nuclear Information System (INIS)

Shapiro, E.; Piomelli, D.; Feinmark, S.; Vogel, S.; Chin, G.; Schwartz, J.H.

1988-01-01

Neuromodulation is a form of signal transduction that results in the biochemical control of neuronal excitability. Many neurotransmitters act through second messengers, and the examination of biochemical cascades initiated by neurotransmitter-receptor interaction has advanced the understanding of how information is acquired and stored in the nervous system. For example, 5-HT and other facilitory transmitters increase cAMP in sensory neurons of Aplysia, which enhances excitability and facilitates transmitter output. The authors have examined the role of arachidonic acid metabolites in a neuronal circuit mediating presynaptic inhibition. L32 cells are a cluster of putative histaminergic neurons that each make dual-action synaptic potentials onto two follower neurons, L10 and L14. The synaptic connections, biophysical properties, and roles in behavior of the L10 and L14 follower cells have been well studied. The types of ion channels causing each component of the L32-L10 and L32-L14 dual actions have been characterized and application of histamine mimics the effects of stimulating L32 in both L10 and L14

Synthesis and release of fatty acids by human trophoblast cells in culture

International Nuclear Information System (INIS)

Coleman, R.A.; Haynes, E.B.

1987-01-01

In order to determine whether placental cells can synthesize and release fatty acids, trophoblast cells from term human placentas were established in monolayer culture. The cells continued to secrete placental lactogen and progesterone and maintained specific activities of critical enzymes of triacylglycerol and phosphatidylcholine biosynthesis for 24 to 72 hr in culture. Fatty acid was rapidly synthesized from [ 14 C]acetate and released by the cells. Palmitoleic, palmitic, and oleic acids were the major fatty acids synthesized from [ 14 C]acetate and released. Small amounts of lauric, myristic, and stearic acids were also identified. [ 14 C]acetate was also incorporated into cellular triacylglycerol, phospholipid, and cholesterol, but radiolabeled free fatty acid did not accumulate intracellularly. In a pulse-chase experiment, cellular glycerolipids were labeled with [1- 14 C]oleate; trophoblast cells then released 14 C-labeled fatty acid into the media as the cellular content of labeled phospholipid and triacylglycerol decreased without intracellular accumulation of free fatty acid. Twenty percent of the 14 C-label lost from cellular glycerolipid could not be recovered as a chloroform-extractable product, suggesting that some of the hydrolyzed fatty acid had been oxidized. These data indicate that cultured placenta trophoblast cells can release fatty acids that have either been synthesized de novo or that have been hydrolyzed from cellular glycerolipids. Trophoblast cells in monolayer culture should provide an excellent model for molecular studies of placental fatty acid metabolism and release

Dietary effects of arachidonate-rich fungal oil and fish oil on murine hepatic and hippocampal gene expression

Directory of Open Access Journals (Sweden)

Mutch David M

2002-10-01

Full Text Available Abstract Background The functions, actions, and regulation of tissue metabolism affected by the consumption of long chain polyunsaturated fatty acids (LC-PUFA from fish oil and other sources remain poorly understood; particularly how LC-PUFAs affect transcription of genes involved in regulating metabolism. In the present work, mice were fed diets containing fish oil rich in eicosapentaenoic acid and docosahexaenoic acid, fungal oil rich in arachidonic acid, or the combination of both. Liver and hippocampus tissue were then analyzed through a combined gene expression- and lipid- profiling strategy in order to annotate the molecular functions and targets of dietary LC-PUFA. Results Using microarray technology, 329 and 356 dietary regulated transcripts were identified in the liver and hippocampus, respectively. All genes selected as differentially expressed were grouped by expression patterns through a combined k-means/hierarchical clustering approach, and annotated using gene ontology classifications. In the liver, groups of genes were linked to the transcription factors PPARα, HNFα, and SREBP-1; transcription factors known to control lipid metabolism. The pattern of differentially regulated genes, further supported with quantitative lipid profiling, suggested that the experimental diets increased hepatic β-oxidation and gluconeogenesis while decreasing fatty acid synthesis. Lastly, novel hippocampal gene changes were identified. Conclusions Examining the broad transcriptional effects of LC-PUFAs confirmed previously identified PUFA-mediated gene expression changes and identified novel gene targets. Gene expression profiling displayed a complex and diverse gene pattern underlying the biological response to dietary LC-PUFAs. The results of the studied dietary changes highlighted broad-spectrum effects on the major eukaryotic lipid metabolism transcription factors. Further focused studies, stemming from such transcriptomic data, will need to

Chemical evolution. XXI - The amino acids released on hydrolysis of HCN oligomers

Science.gov (United States)

Ferris, J. P.; Wos, J. D.; Nooner, D. W.; Oro, J.

1974-01-01

Major amino acids released by hydrolysis of acidic and basic HCN oligomers are identified by chromatography as Gly, Asp, and diaminosuccinic acid. Smaller amounts of Ala, Ile and alpha-aminoisobutyric acid are also detected. The amino acids released did not change appreciably when the hydrolysis medium was changed from neutral to acidic or basic. The presence of both meso and d, l-diaminosuccinic acids was established by paper chromatography and on an amino acid analyzer.

Recognition of acidic phospholipase A2 activity in plasma membranes of resident peritoneal macrophages

International Nuclear Information System (INIS)

Shibata, Y.; Abiko, Y.; Ohno, H.; Araki, T.; Takiguchi, H.

1988-01-01

Phospholipase (PLase) activities in the plasma membrane of guinea pig peritoneal macrophages were studied, as these enzymes having such activity may be candidates for the release of arachidonic acid (AA) from phosphatidylcholine (PC). An AA release system operating at acidic pH was identified in the macrophage plasma membrane and characterized. This membrane-bound acidic PLase A 2 had an optimum pH at 4.5, and enzyme activation was observed in Ca ++ -free medium; but the maximum activity was found at 0.5 mM Ca ++ concentration. The Km value for PC of acidic PLase A 2 was 4.2 μM, and a Michaelis-Menten relationship was evident. Calcium might act as a cofactor at some intermediate step during the activation of acidic PLase A 2 in light of the uncompetitive manner of Ca ++ action. Furthermore, the release of [ 3 H]-AA from preradiolabelled macrophage plasma membranes occurred with the addition of Ca ++ at pH 4.5. These data suggest that the acid PLase A 2 is a component of the plasma membrane and is not due to lysosomal contamination since membrane-bound acidic PLase A 2 properties are opposite to those found for lysosomal PLase A 2

Ameliorative effects of polyunsaturated fatty acids against palmitic acid-induced insulin resistance in L6 skeletal muscle cells

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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.

Intestinal release and uptake of phenolic antioxidant diferulic acids

DEFF Research Database (Denmark)

Andreasen, Mette Findal; Kroon, P A; Williamson, G

2001-01-01

Diferulic acids are potent antioxidants and are abundant structural components of plant cell walls, especially in cereal brans. As such, they are part of many human and animal diets and may contribute to the beneficial effect of cereal brans on health. However, these phenolics are ester-linked to......Diferulic acids are potent antioxidants and are abundant structural components of plant cell walls, especially in cereal brans. As such, they are part of many human and animal diets and may contribute to the beneficial effect of cereal brans on health. However, these phenolics are ester...... in oil. Our study also reveals that human and rat colonic microflora contain esterase activity able to release 5-5-, 8-O-4-, and 8-5-diferulic acids from model compounds and dietary cereal brans, hence providing a mechanism for release of dietary diferulates prior to absorption of the free acids....... In addition, cell-free extracts from human and rat small intestine mucosa exhibited esterase activity towards diferulate esters. Hence, we have shown that esterified diferulates can be released from cereal brans by intestinal enzymes, and that free diferulic acids can be absorbed and enter the circulatory...

Bifidobacterium breve with α-linolenic acid and linoleic acid alters fatty acid metabolism in the maternal separation model of irritable bowel syndrome.

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Eoin Barrett

Full Text Available The aim of this study was to compare the impact of dietary supplementation with a Bifidobacterium breve strain together with linoleic acid & α-linolenic acid, for 7 weeks, on colonic sensitivity and fatty acid metabolism in rats. Maternally separated and non-maternally separated Sprague Dawley rats (n = 15 were orally gavaged with either B. breve DPC6330 (10(9 microorganisms/day alone or in combination with 0.5% (w/w linoleic acid & 0.5% (w/w α-linolenic acid, daily for 7 weeks and compared with trehalose and bovine serum albumin. Tissue fatty acid composition was assessed by gas-liquid chromatography and visceral hypersensitivity was assessed by colorectal distension. Significant differences in the fatty acid profiles of the non-separated controls and maternally separated controls were observed for α-linolenic acid and arachidonic acid in the liver, oleic acid and eicosenoic acid (c11 in adipose tissue, and for palmitoleic acid and docosahexaenoic acid in serum (p<0.05. Administration of B. breve DPC6330 to MS rats significantly increased palmitoleic acid, arachidonic acid and docosahexaenoic acid in the liver, eicosenoic acid (c11 in adipose tissue and palmitoleic acid in the prefrontal cortex (p<0.05, whereas feeding B. breve DPC6330 to non separated rats significantly increased eicosapentaenoic acid and docosapentaenoic acid in serum (p<0.05 compared with the NS un-supplemented controls. Administration of B. breve DPC6330 in combination with linoleic acid and α-linolenic acid to maternally separated rats significantly increased docosapentaenoic acid in the serum (p<0.01 and α-linolenic acid in adipose tissue (p<0.001, whereas feeding B. breve DPC6330 with fatty acid supplementation to non-separated rats significantly increased liver and serum docosapentaenoic acid (p<0.05, and α-linolenic acid in adipose tissue (p<0.001. B. breve DPC6330 influenced host fatty acid metabolism. Administration of B. breve DPC6330 to maternally separated

On methods for the detection of reactive oxygen species generation by human spermatozoa: analysis of the cellular responses to catechol oestrogen, lipid aldehyde, menadione and arachidonic acid.

Science.gov (United States)

Aitken, R J; Smith, T B; Lord, T; Kuczera, L; Koppers, A J; Naumovski, N; Connaughton, H; Baker, M A; De Iuliis, G N

2013-03-01

Oxidative stress is known to have a major impact on human sperm function and, as a result, there is a need to develop sensitive methods for measuring reactive oxygen species (ROS) generation by these cells. A variety of techniques have been developed for this purpose including chemiluminescence (luminol and lucigenin), flow cytometry (MitoSOX Red, dihydroethidium, 4,5-diaminofluorescein diacetate and 2',7'-dichlorodihydrofluorescein diacetate) and spectrophotometry (nitroblue tetrazolium). The relative sensitivity of these assays and their comparative ability to detect ROS generated in different subcellular compartments of human spermatozoa, have not previously been investigated. To address this issue, we have compared the performance of these assays when ROS generation was triggered with a variety of reagents including 2-hydroxyestradiol, menadione, 4-hydroxynonenal and arachidonic acid. The results revealed that menadione predominantly induced release of ROS into the extracellular space where these metabolites could be readily detected by luminol-peroxidase and, to a lesser extent, 2',7'-dichlorodihydrofluorescein. However, such sensitivity to extracellular ROS meant that these assays were particularly vulnerable to interference by leucocytes. The remaining reagents predominantly elicited ROS generation by the sperm mitochondria and could be optimally detected by MitoSOX Red and DHE. Examination of spontaneous ROS generation by defective human spermatozoa revealed that MitoSOX Red was the most effective indicator of oxidative stress, thereby emphasizing the general importance of mitochondrial dysregulation in the aetiology of defective sperm function. © 2013 American Society of Andrology and European Academy of Andrology.

Participation of Arachidonic Acid Metabolism in the Aortic Aneurysm Formation in Patients with Marfan Syndrome

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María E. Soto

2018-02-01

Full Text Available Marfan syndrome (MFS is a pleiotropic genetic disease involving the cardiovascular system where a fibrillin-1 mutation is present. This mutation is associated with accelerated activation of transforming growth factor β (TGFβ1 which contributes to the formation of aneurysms in the root of the aorta. There is an imbalance in the synthesis of thromboxane A2 (TXA2 and prostacyclin, that is a consequence of a differential protein expression of the isoforms of cyclooxygenases (COXs, suggesting an alteration of arachidonic acid (AA metabolism. The aim of this study was to analyze the participation of AA metabolism associated with inflammatory factors in the dilation and dissection of the aortic aneurysm in patients with MFS. A decrease in AA (p = 0.02, an increase in oleic acid (OA, TGFβ1, tumor necrosis factor alpha (TNFα, prostaglandin E2 (PGE2 (p < 0.05, and COXs activity (p = 0.002 was found. The expressions of phospholipase A2 (PLA2, cytochrome P450 (CYP450 4A, 5-lipoxygenase (5-LOX, COX2 and TXA2R (p < 0.05 showed a significant increase in the aortic aneurysm of patients with MFS compared to control subjects. COX1, 6-keto-prostaglandin 1 alpha (6-keto-PG1α and 8-isoprostane did not show significant changes. Histological examination of the aortas showed an increase of cystic necrosis, elastic fibers and collagen in MFS. The results suggest that there are inflammatory factors coupled to genetic factors that predispose to aortic endothelial dysfunction in the aortic tissue of patients with MFS. There is a decrease in the percentage of AA, associated with an increase of PLA2, COX2/TXA2R, CYP450 4A, and 5-LOX which leads to a greater synthesis of PGE2 than of 6-keto-PGF1α, thus contributing to the formation of the aortic aneurysm. The evident loss of the homeostasis in these mechanisms confirms that there is a participation of the AA pathway in the aneurysm progression in MFS.

Mechanistic Perspectives of Maslinic Acid in Targeting Inflammation

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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.

Transient postnatal fluoxetine decreases brain concentrations of 20-HETE and 15-epi-LXA4, arachidonic acid metabolites in adult mice.

Science.gov (United States)

Yuan, Zhi-Xin; Rapoport, Stanley I

2015-10-01

Transient postnatal exposure of rodents to the selective serotonin (5-HT) reuptake inhibitor (SSRI) fluoxetine alters behavior and brain 5-HT neurotransmission during adulthood, and also reduces brain arachidonic (ARA) metabolic consumption and protein level of the ARA metabolizing enzyme, cytochrome P4504A (CYP4A). Brain 20-hydroxyeicosatetraenoic acid (20-HETE), converted by CYP4A from ARA, will be reduced in adult mice treated transiently and postnatally with fluoxetine. Male mice pups were injected i.p. daily with fluoxetine (10mg/kg) or saline during P4-P21. At P90 their brain was high-energy microwaved and analyzed for 20-HETE and six other ARA metabolites by enzyme immunoassay. Postnatal fluoxetine vs. saline significantly decreased brain concentrations of 20-HETE (-70.3%) and 15-epi-lipoxin A4 (-60%) in adult mice, but did not change other eicosanoid concentrations. Behavioral changes in adult mice treated postnatally with fluoxetine may be related to reduced brain ARA metabolism involving CYP4A and 20-HETE formation. Published by Elsevier Ltd.

Arachidonic acid and DHA status in pregnant women is not associated with cognitive performance of their children at 4 or 6-7 years.

Science.gov (United States)

Crozier, Sarah R; Sibbons, Charlene M; Fisk, Helena L; Godfrey, Keith M; Calder, Philip C; Gale, Catharine R; Robinson, Sian M; Inskip, Hazel M; Baird, Janis; Harvey, Nicholas C; Cooper, Cyrus; Burdge, Graham C

2018-06-01

Arachidonic acid (ARA) and DHA, supplied primarily from the mother, are required for early development of the central nervous system. Thus, variations in maternal ARA or DHA status may modify neurocognitive development. We investigated the relationship between maternal ARA and DHA status in early (11·7 weeks) or late (34·5 weeks) pregnancy on neurocognitive function at the age of 4 years or 6-7 years in 724 mother-child pairs from the Southampton Women's Survey cohort. Plasma phosphatidylcholine fatty acid composition was measured in early and late pregnancy. ARA concentration in early pregnancy predicted 13 % of the variation in ARA concentration in late pregnancy (β=0·36, PDHA concentration in early pregnancy predicted 21 % of the variation in DHA concentration in late pregnancy (β=0·46, PDHA nor ARA concentrations in early or late pregnancy were associated significantly with neurocognitive function in children at the age of 4 years or the age of 6-7 years. These findings suggest that ARA and DHA status during pregnancy in the range found in this cohort are unlikely to have major influences on neurocognitive function in healthy children.

Digestion of thyroglobulin with purified thyroid lysosomes: preferential release of iodoamino acids

International Nuclear Information System (INIS)

Tokuyama, T.; Yoshinari, M.; Rawitch, A.B.; Taurog, A.

1987-01-01

[ 131 I]Thyroglobulin [( 131 I]Tg), prepared by either enzymatic iodination of human goiter Tg in vitro or isolation from the thyroids of rats previously injected with 131 I, was digested with a solubilized enzyme mixture prepared from purified hog thyroid lysosomes. The digestion was performed at 37 C for 24 h under nitrogen at pH 5.0 in the presence of 4 mM dithiothreitol. Under these conditions the release of free [ 131 I] iodoamino acids (MIT, DIT, T4, and T3) was quantitatively very similar to that observed with a standard pronase digestion procedure. To determine whether other amino acids in Tg were released as quantitatively as the iodoamino acids, free amino acids in the lysosomal digest were measured, and total free amino acid release was compared with a similar analysis performed after digestion of [ 131 I]Tg with 6 N HCl. Total amino acid release was much less complete than iodoamino acid release, indicating preferential release of iodoamino acids from Tg by lysosomal digestion. Analysis of the lysosomal digest by HPLC on a size exclusion column indicated that Tg was degraded to peptides with a mol wt less than 4000. Assuming that the in vitro lysosomal digestion system represents a valid model for the physiological proteolytic system that degrades Tg, the results of the present study suggest that a substantial portion of the Tg in the thyroid is not degraded to free amino acids and that peptide fragments of Tg are normally present in the thyroid. In such a case, the fate and possible physiological activity of these fragments require further elucidation

Development of a Controlled Release of Salicylic Acid Loaded Stearic Acid-Oleic Acid Nanoparticles in Cream for Topical Delivery

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J. O. Woo

2014-01-01

Full Text Available Lipid nanoparticles are colloidal carrier systems that have extensively been investigated for controlled drug delivery, cosmetic and pharmaceutical applications. In this work, a cost effective stearic acid-oleic acid nanoparticles (SONs with high loading of salicylic acid, was prepared by melt emulsification method combined with ultrasonication technique. The physicochemical properties, thermal analysis and encapsulation efficiency of SONs were studied. TEM micrographs revealed that incorporation of oleic acid induces the formation of elongated spherical particles. This observation is in agreement with particle size analysis which also showed that the mean particle size of SONs varied with the amount of OA in the mixture but with no effect on their zeta potential values. Differential scanning calorimetry analysis showed that the SONs prepared in this method have lower crystallinity as compared to pure stearic acid. Different amount of oleic acid incorporated gave different degree of perturbation to the crystalline matrix of SONs and hence resulted in lower degrees of crystallinity, thereby improving their encapsulation efficiencies. The optimized SON was further incorporated in cream and its in vitro release study showed a gradual release for 24 hours, denoting the incorporation of salicylic acid in solid matrix of SON and prolonging the in vitro release.

Glucose-stimulated acrolein production from unsaturated fatty acids.

Science.gov (United States)

Medina-Navarro, R; Duran-Reyes, G; Diaz-Flores, M; Hicks, J J; Kumate, J

2004-02-01

Glucose auto-oxidation may be a significant source of reactive oxygen species (ROS), and also be important in the lipid peroxidation process, accompanied by the release of toxic reactive products. We wanted to demonstrate that acrolein can be formed directly and actively from free fatty acids in a hyperglycemic environment. A suspension of linoleic and arachidonic acids (2.5 mM) was exposed to different glucose concentrations (5, 10 and 15 mmol/L) in vitro. The samples were extracted with organic solvents, partitioned, followed at 255-267 nm, and analysed using capillary electrophoresis and mass spectroscopy. The total release of aldehydes significantly (P products, acrolein (5% of total) and its condensing product, 4-hydroxy-hexenal, were identified. From the results presented here, it was possible to demonstrate the production of acrolein, probably as a fatty acid product, due to free radicals generated from the glucose auto-oxidation process. The results led us to propose that acrolein, which is one of the most toxic aldehydes, is produced during hyperglycemic states, and may lead to tissue injury, as one of the initial problems to be linked to high levels of glucose in vivo.

Hypercholesterolemia increases plasma saturated and n-6 fatty acids altering prostaglandin homeostasis and promotes endothelial dysfunction in rabbits.

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Medina, M; Alberto, M R; Sierra, L; Van Nieuwenhove, C; Saad, S; Isla, M I; Jerez, S

2014-07-01

The present study evaluated the plasma fatty acid levels and the vascular prostaglandin (PG) release in a rabbit model of early hypercholesterolemia with endothelial dysfunction. Rabbits were fed either a control diet (CD) or a diet containing 1 % cholesterol (HD) for 5-6 weeks. The level of fatty acids was measured in plasma. The levels of PG and nitric oxide (NO) released from the aorta were also determined. Vascular morphology of the aorta was characterized by intima and media thickness measurements. The rabbits fed with HD had higher levels of arachidonic acid (ARA) and lower levels of oleic acid. The linoleic acid level was unchanged. PGI(2) and NO were diminished and PGF(2α) levels, the PGI(2)/TXA(2) ratio and the intima/media ratio were increased in rabbits fed with HD. In conclusion, feeding HD for a short period increased ARA plasma levels and unbalanced release of vasodilator/vasoconstrictor PG redirected the pathway to vasoconstrictor metabolite release. These lipid metabolism alterations in addition to the reduced NO levels and the moderate changes in the vascular morphology contributed to the endothelial dysfunction in this animal model. Therefore, the present findings support the importance of early correction or prevention of high cholesterol levels to disrupt the endothelial dysfunction process that leads to cardiovascular disease.

Decreased Polyunsaturated Fatty Acid Content Contributes to Increased Survival in Human Colon Cancer

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Manuela Oraldi

2009-01-01

Full Text Available Among diet components, some fatty acids are known to affect several stages of colon carcinogenesis, whereas others are probably helpful in preventing tumors. In light of this, our aim was to determine the composition of fatty acids and the possible correlation with apoptosis in human colon carcinoma specimens at different Duke's stages and to evaluate the effect of enriching human colon cancer cell line with the possible reduced fatty acid(s. Specimens of carcinoma were compared with the corresponding non-neoplastic mucosa: a significant decrease of arachidonic acid, PPARα, Bad, and Bax and a significant increase of COX-2, Bcl-2, and pBad were found. The importance of arachidonic acid in apoptosis was demonstrated by enriching a Caco-2 cell line with this fatty acid. It induced apoptosis in a dose- and time-dependent manner via induction of PPARα that, in turn, decreased COX-2. In conclusion, the reduced content of arachidonic acid is likely related to carcinogenic process decreasing the susceptibility of cancer cells to apoptosis.

Arachidonic acid metabolomic study of BPH in rats and the interventional effects of Zishen pill, a traditional Chinese medicine.

Science.gov (United States)

Bian, Qiaoxia; Wang, Weihui; Wang, Nannan; Peng, Yan; Ma, Wen; Dai, Ronghua

2016-09-05

Zishen pill (ZSP) is a traditional Chinese medicine (TCM) used to treat benign prostatic hyperplasia (BPH). The study used a metabolomic approach based on UHPLC-MS/MS to profile arachidonic acid (AA) metabolic changes and to investigate the interventional mechanisms of ZSP in testosterone- induced BPH rats. In order to explore the potential therapeutic effect of ZSP, rat models were constructed and orally administrated with ZSP. Plasma and urine samples were collected after four weeks and then eleven potential biomarkers (15-HETE, 12-HETE, TXA2, 5-HETE, AA, PGI2, PGF2α, 8-HETE, PGD2, PGE2 and LTB4) were identified and quantified by UHPLC-MS/MS. The chromatographic separation was carried out with gradient elution using a mobile phase comprised of 0.05% formic acid aqueous solution (pH=3.3) (A) and acetonitrile: methanol (80:20, V/V) (B), and each AA metabolites was measured using electrospray ionization source with negative mode and multiple reaction monitoring. The eleven biomarkers in BPH group rat plasma and urine were significant higher than those in sham group rats. Using the potential biomarkers as a screening index, the results suggest that ZSP can potentially reverse the process of BPH by partially regulating AA metabolism through refrain the expression of cyclooxygenase (COX) and lipoxygenase (LOX). This study demonstrates that a metabolomic strategy is useful for identifying potential BPH biomarkers and investigating the underlying mechanisms of a TCM in BPH treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

Safety and tolerability of prolonged-release nicotinic acid in statin-treated patients

NARCIS (Netherlands)

Birjmohun, R. S.; Kastelein, J. J. P.; Poldermans, D.; Stroes, E. S. G.; Hostalek, U.; Assmann, G.

2007-01-01

Objective: To evaluate the safety and tolerability of prolonged -release nicotinic acid (Niaspan*) added to statin therapy in patients at increased cardiovascular risk. Methods: This was a 6-month, prospective, observational, multicentre, open-label evaluation of prolonged-release nicotinic acid

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

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Gaoliang Yan

Full Text Available 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.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.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.

Phosphorus release from phosphate rock and iron phosphate by low-molecular-weight organic acids.

Science.gov (United States)

Xu, Ren-kou; Zhu, Yong-guan; Chittleborough, David

2004-01-01

Low-molecular-weight(LMW) organic acids widely exist in soils, particularly in the rhizosphere. A series of batch experiments were carried out to investigate the phosphorus release from rock phosphate and iron phosphate by low-molecular-weight organic acids. Results showed that citric acid had the highest capacity to solubilize P from both rock and iron phosphate. P solubilization from rock phosphate and iron phosphate resulted in net proton consumption. P release from rock phosphate was positively correlated with the pKa values. P release from iron phosphate was positively correlated with Fe-organic acid stability constants except for aromatic acids, but was notcorrelated with pKa. Increase in the concentrations of organic acids enhanced P solubilization from both rock and iron phosphate almost linearly. Addition of phenolic compounds further increased the P release from iron phosphate. Initial solution pH had much more substantial effect on P release from rock phosphate than from iron phosphate.

Adsorption and release of ofloxacin from acid- and heat-treated halloysite.

Science.gov (United States)

Wang, Qin; Zhang, Junping; Zheng, Yue; Wang, Aiqin

2014-01-01

Halloysite nanotube is an ideal vehicle of the controlled release of drugs. In this study, we systematically investigated the effects of acid- and heat-treatments on the physicochemical properties, structure and morphology of halloysite by XRD, FTIR, SEM and TEM. Afterwards, the adsorption and in vitro release properties of halloysite for cationic ofloxacin (OFL) were evaluated. The results indicate that HCl treatment has no influence on the crystal structure of halloysite, whereas it becomes amorphous after calcined at temperature higher than 500 °C. Both acid- and heat-treatments have no evident influence on the tubular structure of halloysite. OFL was adsorbed onto halloysite via electrostatic interaction between protonated OFL and negative halloysite surface, cation exchange as well as electrostatic interaction between the OFL-Al(3+) complexes and the negative halloysite surface. Acid-treatment facilitates the release of the adsorbed OFL compared with the natural halloysite in spite of a slight decrease of adsorption capacity. However, heat-treatment results in a sharp decrease of adsorption capacity for OFL owning to the OFL-promoted dissolution of aluminum and the disappearance of the porous structure. Although heat-treatment also facilitates release of the adsorbed OFL, the amount of OFL released is in fact less than the natural halloysite owing to the very low adsorption capacity. Thus, acid-activation is an effective protocol to improve the adsorption and release of halloysite for cationic drug molecules. Copyright © 2013 Elsevier B.V. All rights reserved.

Changes of fatty acid aerosol hygroscopicity induced by ozonolysis under humid conditions

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O. Vesna

2008-08-01

Full Text Available Unsaturated fatty acids are important constituents of the organic fraction of atmospheric aerosols originating from biogenic or combustion sources. Oxidative processing of these may change their interaction with water and thus affect their effect on climate. The ozonolysis of oleic and arachidonic acid aerosol particles was studied under humid conditions in a flow reactor at ozone exposures close to atmospheric levels, at concentrations between 0.5 and 2 ppm. While oleic acid is a widely used proxy for such studies, arachidonic acid represents polyunsaturated fatty acids, which may decompose into hygroscopic products. The hygroscopic (diameter growth factor at 93% relative humidity (RH of the oxidized arachidonic particles increased up to 1.09 with increasing RH during the ozonolysis. In contrast, the growth factor of oleic acid was very low (1.03 at 93% RH and was almost invariant to the ozonolysis conditions, so that oleic acid is not a good model to observe oxidation induced changes of hygroscopicity under atmospheric conditions. We show for arachidonic acid particles that the hygroscopic changes induced by humidity during ozonolysis are accompanied by about a doubling of the ratio of carboxylic acid protons to aliphatic protons. We suggest that, under humid conditions, the reaction of water with the Criegee intermediates might open a pathway for the formation of smaller acids that lead to more significant changes in hygroscopicity. Thus the effect of water to provide a competing pathway during ozonolysis observed in this study should be motivation to include water, which is ubiquitously present in and around atmospheric particles, in future studies related to aerosol particle aging.

Metabolism of phosphatidylinositol in plasma membranes and synaptosomes of rat cerebral cortex: A comparison between endogenous vs exogenous substrate pools

International Nuclear Information System (INIS)

Navidi, M.; MacQuarrie, R.A.; Sun, G.Y.

1990-01-01

The metabolism of phosphatidylinositols (PI) labeled with [14C]arachidonic acid within plasma membranes or synaptosomes was compared to the metabolism of PI prelabeled with [14C]arachidonic acid and added exogenously to the same membranes. Incubation of membranes containing the endogenously-labeled PI pool in the presence of Ca2+ resulted in the release of labeled arachidonic acid, as well as a small amount of labeled diacylglycerol. Labeled arachidonic acid was effectively reutilized and returned to the membrane phospholipids in the presence of adenosine triphosphate (ATP), CoA, and lysoPI. Although Ca2+ promoted the release of labeled diacylglycerol from prelabeled plasma membranes, this amount was only 17% of the maximal release, i.e., release in the presence of deoxycholate and Ca2+. This latter condition is known to fully activate the PI-phospholipase C, and incubation of prelabeled plasma membranes resulted in a six-fold increase in labeled diacylglycerols. On the other hand, when exogenously labeled PI were incubated with plasma membranes in the presence of Ca2+, the labeled diacylglycerols released were 59% of that compared to the fully activated condition. The phospholipase C action was calcium-dependent, regardless of whether exogenous or endogenous substrates were used in the incubation. In contrast to plasma membranes, intact synaptosomes had limited ability to metabolize exogenous PI even in the presence of Ca2+, although the activity of phospholipase C was similar to that in the plasma membranes when assayed in the presence of deoxycholate and Ca2+. These results suggest that discrete pools of PI are present in plasma membranes, and that the pool associated with the acyltransferase is apparently not readily accessible to hydrolysis by phospholipase C

Metabolism of arachidonic acid in 1 yr old New Zealand white (NZW) and watanabe heritable hyperlipidemic (WHHL) rabbit aortas

International Nuclear Information System (INIS)

Pfister, S.L.; Schmitz, J.M.; Willerson, J.T.; Campbell, W.B.

1986-01-01

This study was designed to characterize the metabolism of arachidonic acid (AA) in normal and atherosclerotic aortas. Segments of aortas were obtained from 1 yr old NZW rabbits, and WHHL rabbits, a genetic model of athero-sclerosis resembling familial hypercholesterolemia. Aortas were incubated at 37 0 C for 15 min with 14 C-AA (5 x 10 -5 M) during stimulation by A23187. The media was extracted using octadecylsilica columns and resolved into metabolites by reverse-phase HPLC. Prostaglandins (PGs) were identified by comigration of 14 C-metabolites with standards. The monoxygenated metabolites of AA (HETEs) were resolved by normal-phase HPLC, and their structures confirmed by GC-MS. In extracts from NZW and WHHL aortas, approximately 14% and 6% of the total radioactivity was converted to PGs and HETEs, respectively. The major PG produced by NZW and WHHL aortas was 6-keto PGF/sub 1α/ with lesser amounts of PGE 2 . Similarly, NZW and WHHL aortas produced primarily 12- and 15-HETE with lesser amounts of 11-, 9-, 8-, and 5-HETE. There were no qualitative differences between NZW and WHHL aortas in PG and HETE production. Therefore, despite extensive atherosclerosis in aortas of WHHL rabbits, the vessels maintain the ability to synthesize PGs and HETEs

Arachidonic acid containing phosphatidylcholine increases due to microglial activation in ipsilateral spinal dorsal horn following spared sciatic nerve injury.

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Tomohiro Banno

Full Text Available Peripheral nerve injury induces substantial molecular changes in the somatosensory system that leads to maladaptive plasticity and cause neuropathic pain. Understanding the molecular pathways responsible for the development of neuropathic pain is essential to the development of novel rationally designed therapeutics. Although lipids make up to half of the dry weight of the spinal cord, their relation with the development of neuropathic pain is poorly understood. We aimed to elucidate the regulation of spinal lipids in response to neuropathic peripheral nerve injury in mice by utilizing matrix-assisted laser desorption/ionization imaging mass spectrometry, which allows visualization of lipid distribution within the cord. We found that arachidonic acid (AA containing [PC(diacyl-16:0/20:4+K]+ was increased temporarily at superficial ipsilateral dorsal horn seven days after spared nerve injury (SNI. The spatiotemporal changes in lipid concentration resembled microglia activation as defined by ionized calcium binding adaptor molecule 1 (Iba1 immunohistochemistry. Suppression of microglial function through minocycline administration resulted in attenuation of hypersensitivity and reduces [PC(diacyl-16:0/20:4+K]+ elevation in the spinal dorsal horn. These data suggested that AA containing [PC(diacyl-16:0/20:4+K]+ is related to hypersensitivity evoked by SNI and implicate microglial cell activation in this lipid production.

Controlled Pesticide Release from Porous Composite Hydrogels Based on Lignin and Polyacrylic Acid

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Yajie Sun

2016-01-01

Full Text Available For the controlled release of pesticides, a novel composite porous hydrogel (LBPAA was prepared based on lignin and polyacrylic acid for use as the support frame of a pore structure for water delivery. The LBPAA was analyzed to determine its water-swelling and slow release properties. The controlled release properties of LBPAA were evaluated through experiments in relation to the cumulative release of pesticides, with particular emphasis on environmental effects and release models. The porous LBPAA hydrogel showed improved properties compared to polyacrylic acid, and could therefore be considered an efficient material for application in controlled release systems in agriculture.

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

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Ryan, Veronica H; Primiani, Christopher T; Rao, Jagadeesh S; Ahn, Kwangmi; Rapoport, Stanley I; Blanchard, Helene

2014-01-01

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.

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

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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.

Targeted metabolomics analysis reveals the association between maternal folic acid supplementation and fatty acids and amino acids profiles in rat pups.

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Liu, Zhipeng; Liu, Rui; Chou, Jing; Yu, Jiaying; Liu, Xiaowei; Sun, Changhao; Li, Ying; Liu, Liyan

2018-07-15

Maternal diet during pregnancy can influence offspring's health by affecting development and metabolism. This study aimed to analyze the influence of maternal folic acid (FA) supplementation on the metabolism of rat pups using targeted metabolomics. Twenty female rats were randomly assigned to a FA supplementation (FAS group, n = 10) or control group (n = 10), which were fed AIN93G diet with 2 or 10 mg/kg FA, respectively. We then measured amino acids and their derivatives, biogenic amines, and fatty acids in the female rats and their pups by ultra-high performance liquid chromatography-triple quadrupole mass spectrometry (UHPLC/MS-MS) and gas chromatography-mass spectrometry (GC/MS-MS). In maternal rats, the significant changes of three metabolites (proline, γ-aminobutyric acid and esterified octadecatetraenoic acid, P acids (leucine, isoleucine, serine, proline) were obtained in FAS pups. Furthermore, there were the decreased esterified fatty acids (arachidonic acid, eicosapentaenoic acid, and docosatetraenoic acid) and free fatty acids (oleic acid, linoleic acid, γ-linolenic acid, octadecatetraenoic acid, arachidonic acid, eicosapentaenoic acid and selacholeic acid) in FAS pups. Metabolic changes in the FAS pups were characterized by changes in fatty acids and amino acids. These results suggested that FA supplementation during pregnancy influenced amino acids and fatty acids metabolism in rat pups. This study provides new insights into the regulation of amino acids and fatty acids metabolism during early life. Copyright © 2018 Elsevier B.V. All rights reserved.

Developmentally dependent and different roles of fatty acids OMEGA-6 and OMEGA-3

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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...... that created mutual relationship between those two substances (with immunological basis and following recuperation). The anti-inflammatory actions of PUFA-OMEGA-3 are the most visible (and significant) contrasts as compared with the large affects of namely arachidonic acid and its metabolites....

A human dietary arachidonic acid supplementation study conducted in a metabolic research unit: rationale and design.

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Nelson, G J; Kelley, D S; Emken, E A; Phinney, S D; Kyle, D; Ferretti, A

1997-04-01

While there are many reports of studies that fed arachidonic acid (AA) to animals, there are very few reports of AA feeding to humans under controlled conditions. This 130-d study was conceived as a controlled, symmetrical crossover design with healthy, adult male volunteers. They lived in the metabolic research unit (MRU) of the Western Human Nutrition Research (WHNRC) for the entire study. All food was prepared by the WHNRC kitchen. The basal (low-AA) diet consisted of natural foods (30 en% fat, 15 en% protein, and 55 en% carbohydrate), containing 210 mg/d of AA, and met the recommended daily allowance for all nutrients. The high-AA (intervention) diet was similar except that 1.5 g/d of AA in the form of a triglyceride containing 50% AA replaced an equal amount of high-oleic safflower oil in the basal diet. The subjects (ages 20 to 39) were within -10 to +20% of ideal body weight, nonsmoking, and not allowed alcohol in the MRU. Their exercise level was constant, and their body weights were maintained within 2% of entry level. Subjects were initially fed the low-AA diet for 15 d. On day 16, half of the subjects (group A) wee placed on the high-AA diet, and the other group (B) remained on the low-AA diets. On day 65, the two groups switched diets. On day 115, group B returned to the low-AA diet. This design, assuming no carryover effect, allowed us to merge the data from the two groups, with the data comparison days being 65 (low-AA) and 115 (high-AA) for group B and 130 (low-AA) and 65 (high-AA) for group A. The main indices studied were the fatty acid composition of the plasma, red blood cells, platelets, and adipose tissue; in vitro platelet aggregation, bleeding times, clotting factors; immune response as measured by delayed hypersensitivity skin tests, cellular proliferation of peripheral blood mononuclear cells in response to various mitogens and antigens, natural killer cell activity, and response to measles/mumps/rubella and influenza vaccines; the

Biological and therapeutic effects of ortho-silicic acid and some ortho-silicic acid-releasing compounds: New perspectives for therapy

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Jurkić Lela Munjas

2013-01-01

Full Text Available Abstract Silicon (Si is the most abundant element present in the Earth's crust besides oxygen. However, the exact biological roles of silicon remain unknown. Moreover, the ortho-silicic acid (H4SiO4, as a major form of bioavailable silicon for both humans and animals, has not been given adequate attention so far. Silicon has already been associated with bone mineralization, collagen synthesis, skin, hair and nails health atherosclerosis, Alzheimer disease, immune system enhancement, and with some other disorders or pharmacological effects. Beside the ortho-silicic acid and its stabilized formulations such as choline chloride-stabilized ortho-silicic acid and sodium or potassium silicates (e.g. M2SiO3; M= Na,K, the most important sources that release ortho-silicic acid as a bioavailable form of silicon are: colloidal silicic acid (hydrated silica gel, silica gel (amorphous silicon dioxide, and zeolites. Although all these compounds are characterized by substantial water insolubility, they release small, but significant, equilibrium concentration of ortho-silicic acid (H4SiO4 in contact with water and physiological fluids. Even though certain pharmacological effects of these compounds might be attributed to specific structural characteristics that result in profound adsorption and absorption properties, they all exhibit similar pharmacological profiles readily comparable to ortho-silicic acid effects. The most unusual ortho-silicic acid-releasing agents are certain types of zeolites, a class of aluminosilicates with well described ion(cation-exchange properties. Numerous biological activities of some types of zeolites documented so far might probably be attributable to the ortho-silicic acid-releasing property. In this review, we therefore discuss biological and potential therapeutic effects of ortho-silicic acid and ortho-silicic acid -releasing silicon compounds as its major natural sources.

Cyclic-AMP mediated drugs: differential or global reduction of eicosanoid synthesis in the isolated rat lung?

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Mark J. Post

1992-01-01

Full Text Available In this study the question was addressed whether cAMP mediated drugs induce a differential reduction of branches of the arachidonic acid metabolism rather than a global reduction of eicosanoid synthesis. The isolated lungs of actively sensitized rats were employed to study prostaglandin and leukotriene release in the presence and absence of the cAMP mediated drugs theophylline, milrinone, sulmazole, isobutyl-methylxanthine and salbutamol. The release of eicosanoids as measured by RIA was predominantly basal and continuous, with a mild antigen induced stimulation only for TXB2 and the leukotrienes. All drugs reduced eicosanoid release globally. It is concluded that cAMP mediated drugs interfere with arachidonic acid metabolism at a site proximal to the branching into lipoxygenase and cyclo-oxygenase pathways.

Characterization of unsaturated fatty acid sustained-release microspheres for long-term algal inhibition.

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Ni, Lixiao; Jie, Xiaoting; Wang, Peifang; Li, Shiyin; Hu, Shuzhen; Li, Yiping; Li, Yong; Acharya, Kumud

2015-02-01

The unsaturated fatty acid (linoleic acid) sustained-release microspheres were prepared with linoleic acid (LA) using alginate-chitosan microcapsule technology. These LA sustained-release microspheres had a high encapsulation efficiency (up to 62%) tested by high performance liquid chromatography with a photo diode array. The dry microspheres were characterized by a scanning electron microscope, X-ray diffraction measurement, dynamic thermogravimetric analysis and Fourier transform infrared spectral analysis. The results of characterization showed that the microspheres had good thermal stability (decomposition temperature of 236°C), stable and temperature independent release properties (release time of more than 40 d). Compared to direct dosing of LA, LA sustained-released microspheres could inhibit Microcystis aeruginosa growth to the non-growth state. The results of this study suggested that the LA sustained-release microspheres may be a potential candidate for algal inhibition. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

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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.

Depolarization-induced release of amino acids from the vestibular nuclear complex.

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Godfrey, Donald A; Sun, Yizhe; Frisch, Christopher; Godfrey, Matthew A; Rubin, Allan M

2012-04-01

There is evidence from immunohistochemistry, quantitative microchemistry, and pharmacology for several amino acids as neurotransmitters in the vestibular nuclear complex (VNC), including glutamate, γ-aminobutyrate (GABA), and glycine. However, evidence from measurements of release has been limited. The purpose of this study was to measure depolarization-stimulated calcium-dependent release of amino acids from the VNC in brain slices. Coronal slices containing predominantly the VNC were prepared from rats and perfused with artificial cerebrospinal fluid (ACSF) in an interface chamber. Fluid was collected from the chamber just downstream from the VNC using a microsiphon. Depolarization was induced by 50 mM potassium in either control calcium and magnesium concentrations or reduced calcium and elevated magnesium. Amino acid concentrations in effluent fluid were measured by high performance liquid chromatography. Glutamate release increased fivefold during depolarization in control calcium concentration and twofold in low calcium/high magnesium. These same ratios were 6 and 1.5 for GABA, 2 and 1.3 for glycine, and 2 and 1.5 for aspartate. Differences between release in control and low calcium/high magnesium ACSF were statistically significant for glutamate, GABA, and glycine. Glutamine release decreased during and after depolarization, and taurine release slowly increased. No evidence for calcium-dependent release was found for serine, glutamine, alanine, threonine, arginine, taurine, or tyrosine. Our results support glutamate and GABA as major neurotransmitters in the VNC. They also support glycine as a neurotransmitter and some function for taurine.

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

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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 using......, our data demonstrate that alpha-synuclein has a major role in brain 20:4n-6 metabolism through its modulation of endoplasmic reticulum-localized acyl-CoA synthetase activity, although mutant forms of alpha-synuclein fail to restore this activity....

Masturbation to Orgasm Stimulates the Release of the Endocannabinoid 2-Arachidonoylglycerol in Humans.

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Fuss, Johannes; Bindila, Laura; Wiedemann, Klaus; Auer, Matthias K; Briken, Peer; Biedermann, Sarah V

2017-11-01

Endocannabinoids are critical for rewarding behaviors such as eating, physical exercise, and social interaction. The role of endocannabinoids in mammalian sexual behavior has been suggested because of the influence of cannabinoid receptor agonists and antagonists on rodent sexual activity. However, the involvement of endocannabinoids in human sexual behavior has not been studied. To investigate plasma endocannabinoid levels before and after masturbation in healthy male and female volunteers. Plasma levels of the endocannabinoids 2-arachidonoylglycerol (2-AG), anandamide, the endocannabinoid-like lipids oleoyl ethanolamide and palmitoyl ethanolamide, arachidonic acid, and cortisol before and after masturbation to orgasm. In study 1, endocannabinoid and cortisol levels were measured before and after masturbation to orgasm. In study 2, masturbation to orgasm was compared with a control condition using a single-blinded, randomized, 2-session crossover design. In study 1, masturbation to orgasm significantly increased plasma levels of the endocannabinoid 2-AG, whereas anandamide, oleoyl ethanolamide, palmitoyl ethanolamide, arachidonic acid, and cortisol levels were not altered. In study 2, only masturbation to orgasm, not the control condition, led to a significant increase in 2-AG levels. Interestingly, we also found a significant increase of oleoyl ethanolamide after masturbation to orgasm in study 2. Endocannabinoids might play an important role in the sexual response cycle, leading to possible implications for the understanding and treatment of sexual dysfunctions. We found an increase of 2-AG through masturbation to orgasm in 2 studies including a single-blinded randomized design. The exact role of endocannabinoid release as part of the sexual response cycle and the biological significance of the finding should be studied further. Cannabis and other drug use and the attainment of orgasm were self-reported in the present study. Our data indicate that the

pH-independent release of propranolol hydrochloride from HPMC-based matrices using organic acids

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2008-08-01

Full Text Available Background and purpose of the study: Propranolol HCl, a widely used drug in the treatment of cardiac arrhythmias and hypertension, is a weak basic drug with pH-dependent solubility that may show release problems from sustained release dosage forms at higher pH of small intestine. This might decrease drug bioavailability and cause variable oral absorption. Preparation of a sustained release matrix system with a pH-independent release profile was the aim of the present study. Methods: Three types of organic acids namely tartaric, citric and fumaric acid in the concentrations of 5, 10 and 15 % were added to the matrices prepared by hydroxypropyl methylcellulose (HPMC and dicalcium phosphate. The drug release studies were carried out at pH 1.2 and pH 6.8 separately and mean dissolution time (MDT as well as similarity factor (¦2 were calculated for all formulations. Results and discussion: It was found that incorporation of 5 and 10 % tartaric acid in tablet formulations with 30 % HPMC resulted in a suitable pH-independent release profiles with significant higher ¦2 values (89.9 and 87.6 respectively compared to acid free tablet (58.03. The other two acids did not show the desirable effects. It seems that lower pKa of tartaric acid accompanied by its higher solubility were the main factors in the achievement of pH-independent release profiles.

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.

The effects of photosensitizing antibiotics and ultraviolet irradiation on the biosynthesis of prostaglandins

International Nuclear Information System (INIS)

Lord, J.T.; Ziboh, V.A.; Blick, G.; Poitier, J.; Kursunoglu, I.; Penneys, N.S.

1978-01-01

Oxygenation of arachidonic acid in vitro by calf skin microsomal acetone powder was enhanced by UV-irradiation at wavelengths of 254 and 360 nm. Further enhancement of the oxygenation reaction was observed in the presence of two photosensitizing cyclic antibiotics, tetracycline and demethylchlortetracycline. To test whether or not the oxygenation of arachidonic acid was related to the biosynthesis of prostaglandins, [I- 14 C]-arachidonic acid was incubated with calf skin acetone powder in the presence of UV-irradiation and the cyclic antibiotics. Prostaglandin biosynthesis from arachidonic acid by the calf skin microsomal acetone powder was enhanced after exposure to UV-irradiation at 254 nm and moderately at 360 nm. Incubation in the presence of demethylchlortetra-cycline (0.2 mM) increased prostaglandin biosynthesis approximately 95% over control by UV-irradiation at 254 nm. No significant stimulation of prostaglandin biosynthesis was observed at 360 nm. Non-photosensitizing antibiotics had no effect either on the oxygenation of arachidonic acid or on the biosynthesis of prostaglandin with or without UV-irradiation. It is suggested that the inflammatory reactions associated with these photo-reactive antibiotics may in part, be via the biosynthesis and release of the prostaglandins which are known to produce cutaneous inflammatory reactions. (author)

Amino Acid Transporters and Release of Hydrophobic Amino Acids in the Heterocyst-Forming Cyanobacterium Anabaena sp. Strain PCC 7120

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Rafael Pernil

2015-04-01

Full Text Available Anabaena sp. strain PCC 7120 is a filamentous cyanobacterium that can use inorganic compounds such as nitrate or ammonium as nitrogen sources. In the absence of combined nitrogen, it can fix N2 in differentiated cells called heterocysts. Anabaena also shows substantial activities of amino acid uptake, and three ABC-type transporters for amino acids have been previously characterized. Seven new loci encoding predicted amino acid transporters were identified in the Anabaena genomic sequence and inactivated. Two of them were involved in amino acid uptake. Locus alr2535-alr2541 encodes the elements of a hydrophobic amino acid ABC-type transporter that is mainly involved in the uptake of glycine. ORF all0342 encodes a putative transporter from the dicarboxylate/amino acid:cation symporter (DAACS family whose inactivation resulted in an increased uptake of a broad range of amino acids. An assay to study amino acid release from Anabaena filaments to the external medium was set up. Net release of the alanine analogue α-aminoisobutyric acid (AIB was observed when transport system N-I (a hydrophobic amino acid ABC-type transporter was engaged in the uptake of a specific substrate. The rate of AIB release was directly proportional to the intracellular AIB concentration, suggesting leakage from the cells by diffusion.

Enhancement of bradykinin and resensitization of its B2 receptor.

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Marcic, B; Deddish, P A; Jackman, H L; Erdös, E G

1999-03-01

We studied the enhancement of the effects of bradykinin B2 receptor agonists by agents that react with active centers of angiotensin-converting enzyme (ACE) independent of enzymatic inactivation. The potentiation and the desensitization and resensitization of B2 receptor were assessed by measuring [3H]arachidonic acid release and [Ca2+]i mobilization in Chinese hamster ovary cells transfected to express human ACE and B2 receptor, or in endothelial cells with constitutively expressed ACE and receptor. Administration of bradykinin or its ACE-resistant analogue desensitized the receptor, but it was resensitized (arachidonic acid release or [Ca2+]i mobilization) by agents such as enalaprilat (1 micromol/L). Enalaprilat was inactive in the absence of ACE expression. La3+ (100 micromol/L) inhibited the apparent resensitization, probably by blocking the entry of extracellular calcium. Enalaprilat resensitized the receptor via ACE to release arachidonic acid by bradykinin at a lower concentration (5 nmol/L) than required to mobilize [Ca2+]i (1 micromol/L). Monoclonal antibodies inhibiting the ACE N-domain active center and polyclonal antiserum potentiated bradykinin. The snake venom peptide BPP5a and metabolites of angiotensin and bradykinin (angiotensin-[1-9], angiotensin-[1-7], bradykinin-[1-8]; 1 micromol/L) enhanced arachidonic acid release by bradykinin. Angiotensin-(1-9) and -(1-7) also resensitized the receptor. Enalaprilat potentiated the bradykinin effect in cells expressing a mutant ACE with a single N-domain active site. Agents that reacted with a single active site, on the N-domain or on the C-domain, potentiated bradykinin not by blocking its inactivation but by inducing crosstalk between ACE and the receptor. Enalaprilat enhanced signaling via ACE by Galphai in lower concentration than by Galphaq-coupled receptor.

Acid-Labile Acyclic Cucurbit[n]uril Molecular Containers for Controlled Release.

Science.gov (United States)

Mao, Dake; Liang, Yajun; Liu, Yamin; Zhou, Xianhao; Ma, Jiaqi; Jiang, Biao; Liu, Jia; Ma, Da

2017-10-02

Stimuli-responsive molecular containers are of great importance for controlled drug delivery and other biomedical applications. A new type of acid labile acyclic cucurbit[n]uril (CB[n]) molecular containers is presented that can degrade and release the encapsulated cargo at accelerated rates under mildly acidic conditions (pH 5.5-6.5). These containers retain the excellent recognition properties of CB[n]-type hosts. A cell culture study demonstrated that the cellular uptake of cargos could be fine-tuned by complexation with different containers. The release and cell uptake of cargo dye was promoted by acidic pH. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The preparation and the sustained release of titanium dioxide hollow particles encapsulating L-ascorbic acid

Science.gov (United States)

Tominaga, Yoko; Kadota, Kazunori; Shimosaka, Atsuko; Yoshida, Mikio; Oshima, Kotaro; Shirakawa, Yoshiyuki

2018-05-01

The preparation of the titanium dioxide hollow particles encapsulating L-ascorbic acid via sol-gel process using inkjet nozzle has been performed, and the sustained release and the effect protecting against degradation of L-ascorbic acid in the particles were investigated. The morphology of titanium dioxide particles was evaluated by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). The sustained release and the effect protecting against degradation of L-ascorbic acid were estimated by dialysis bag method in phosphate buffer saline (PBS) (pH = 7.4) as release media. The prepared titanium dioxide particles exhibited spherical porous structures. The particle size distribution of the titanium dioxide particles was uniform. The hollow titanium dioxide particles encapsulating L-ascorbic acid showed the sustained release. It was also found that the degradation of L-ascorbic acid could be inhibited by encapsulating L-ascorbic acid in the titanium dioxide hollow particles.

Long-chain n-3 fatty acids and inflammation: potential application in surgical and trauma patients

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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.

Antimony leaching release from brake pads: Effect of pH, temperature and organic acids.

Science.gov (United States)

Hu, Xingyun; He, Mengchang; Li, Sisi

2015-03-01

Metals from automotive brake pads pollute water, soils and the ambient air. The environmental effect on water of antimony (Sb) contained in brake pads has been largely untested. The content of Sb in one abandoned brake pad reached up to 1.62×10(4) mg/kg. Effects of initial pH, temperature and four organic acids (acetic acid, oxalic acid, citric acid and humic acid) on Sb release from brake pads were studied using batch reactors. Approximately 30% (97 mg/L) of the total Sb contained in the brake pads was released in alkaline aqueous solution and at higher temperature after 30 days of leaching. The organic acids tested restrained Sb release, especially acetic acid and oxalic acid. The pH-dependent concentration change of Sb in aqueous solution was best fitted by a logarithmic function. In addition, Sb contained in topsoil from land where brake pads were discarded (average 9×10(3) mg/kg) was 3000 times that in uncontaminated soils (2.7±1 mg/kg) in the same areas. Because potentially high amounts of Sb may be released from brake pads, it is important that producers and environmental authorities take precautions. Copyright © 2015. Published by Elsevier B.V.

Immunoregulatory and anti-inflammatory effects of n-3 polyunsaturated fatty acids

Directory of Open Access Journals (Sweden)

P.C. Calder

1998-04-01

Full Text Available 1. Fish oils are rich in the long-chain n-3 polyunsaturated fatty acids (PUFAs, eicosapentaenoic (20:5n-3 and docosahexaenoic (22:6n-3 acids. Linseed oil and green plant tissues are rich in the precursor fatty acid, a-linolenic acid (18:3n-3. Most vegetable oils are rich in the n-6 PUFA linoleic acid (18:2n-6, the precursor of arachidonic acid (20:4n-6. 2. Arachidonic acid-derived eicosanoids such as prostaglandin E2 are pro-inflammatory and regulate the functions of cells of the immune system. Consumption of fish oils leads to replacement of arachidonic acid in cell membranes by eicosapentaenoic acid. This changes the amount and alters the balance of eicosanoids produced. 3. Consumption of fish oils diminishes lymphocyte proliferation, T-cell-mediated cytotoxicity, natural killer cell activity, macrophage-mediated cytotoxicity, monocyte and neutrophil chemotaxis, major histocompatibility class II expression and antigen presentation, production of pro-inflammatory cytokines (interleukins 1 and 6, tumour necrosis factor and adhesion molecule expression. 4. Feeding laboratory animals fish oil reduces acute and chronic inflammatory responses, improves survival to endotoxin and in models of autoimmunity and prolongs the survival of grafted organs. 5. Feeding fish oil reduces cell-mediated immune responses. 6. Fish oil supplementation may be clinically useful in acute and chronic inflammatory conditions and following transplantation. 7. n-3 PUFAs may exert their effects by modulating signal transduction and/or gene expression within inflammatory and immune cells.

Effect of different polyphenol sources on the efficiency of ellagic acid release by Aspergillus niger.

Science.gov (United States)

Sepúlveda, Leonardo; de la Cruz, Reynaldo; Buenrostro, José Juan; Ascacio-Valdés, Juan Alberto; Aguilera-Carbó, Antonio Francisco; Prado, Arely; Rodríguez-Herrera, Raúl; Aguilar, Cristóbal Noé

2016-01-01

Fungal hydrolysis of ellagitannins produces hexahydroxydiphenic acid, which is considered an intermediate molecule in ellagic acid release. Ellagic acid has important and desirable beneficial health properties. The aim of this work was to identify the effect of different sources of ellagitannins on the efficiency of ellagic acid release by Aspergillus niger. Three strains of A. niger (GH1, PSH and HT4) were assessed for ellagic acid release from different polyphenol sources: cranberry, creosote bush, and pomegranate used as substrate. Polyurethane foam was used as support for solid-state culture in column reactors. Ellagitannase activity was measured for each of the treatments. Ellagic acid was quantified by high performance liquid chromatography. When pomegranate polyphenols were used, a maximum value of ellagic acid (350.21 mg/g) was reached with A. niger HT4 in solid-state culture. The highest amount of ellagitannase (5176.81 U/l) was obtained at 8h of culture when cranberry polyphenols and strain A. niger PSH were used. Results demonstrated the effect of different polyphenol sources and A. niger strains on ellagic acid release. It was observed that the best source for releasing ellagic acid was pomegranate polyphenols and A. niger HT4 strain, which has the ability to degrade these compounds for obtaining a potent bioactive molecule such as ellagic acid. Copyright © 2015 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Omega-6 fatty acid biomarkers and incident type 2 diabetes

NARCIS (Netherlands)

Wu, Jason H.Y.; Marklund, Matti; Imamura, Fumiaki; Tintle, Nathan; Ardisson Korat, Andres V.; Goede, de Janette; Zhou, Xia; Yang, Wei Sin; Oliveira Otto, de Marcia C.; Kröger, Janine; Qureshi, Waqas; Virtanen, Jyrki K.; Bassett, Julie K.; Frazier-Wood, Alexis C.; Lankinen, Maria; Murphy, Rachel A.; Rajaobelina, Kalina; Gobbo, Del Liana C.; Forouhi, Nita G.; Luben, Robert; Khaw, Kay Tee; Wareham, Nick; Kalsbeek, Anya; Veenstra, Jenna; Luo, Juhua; Hu, Frank B.; Lin, Hung Ju; Siscovick, David S.; Boeing, Heiner; Chen, Tzu An; Steffen, Brian; Steffen, Lyn M.; Hodge, Allison; Eriksdottir, Gudny; Smith, Albert V.; Gudnason, Vilmunder; Harris, Tamara B.; Brouwer, Ingeborg A.; Berr, Claudine; Helmer, Catherine; Samieri, Cecilia; Laakso, Markku; Tsai, Michael Y.; Giles, Graham G.; Nurmi, Tarja; Wagenknecht, Lynne; Schulze, Matthias B.; Lemaitre, Rozenn N.; Chien, Kuo Liong; Soedamah-Muthu, Sabita S.; Geleijnse, Johanna M.; Sun, Qi; Harris, William S.; Lind, Lars; Ärnlöv, Johan; Riserus, Ulf; Micha, Renata; Mozaffarian, Dariush

2017-01-01

Background: The metabolic effects of omega-6 polyunsaturated fatty acids (PUFAs) remain contentious, and little evidence is available regarding their potential role in primary prevention of type 2 diabetes. We aimed to assess the associations of linoleic acid and arachidonic acid biomarkers with

Regulation of cytosolic Phospholipase A2 activity plays a central role in cell responses

NARCIS (Netherlands)

Rossum, Gerarda Sophia Agnes Theodora van

2001-01-01

Phospholipases A2 are enzymes that hydrolyse fatty acids from the sn-2 position of phospholipids, resulting in the release of free fatty acids and lysophospholipids. The sn-2 position of phospholipids in mammalian cells is enriched with arachidonic acid, which is a substrate for cyclooxygenases,

Micromotors Spontaneously Neutralize Gastric Acid for pH-Responsive Payload Release.

Science.gov (United States)

Li, Jinxing; Angsantikul, Pavimol; Liu, Wenjuan; Esteban-Fernández de Ávila, Berta; Thamphiwatana, Soracha; Xu, Mingli; Sandraz, Elodie; Wang, Xiaolei; Delezuk, Jorge; Gao, Weiwei; Zhang, Liangfang; Wang, Joseph

2017-02-13

The highly acidic gastric environment creates a physiological barrier for using therapeutic drugs in the stomach. While proton pump inhibitors have been widely used for blocking acid-producing enzymes, this approach can cause various adverse effects. Reported herein is a new microdevice, consisting of magnesium-based micromotors which can autonomously and temporally neutralize gastric acid through efficient chemical propulsion in the gastric fluid by rapidly depleting the localized protons. Coating these micromotors with a cargo-containing pH-responsive polymer layer leads to autonomous release of the encapsulated payload upon gastric-acid neutralization by the motors. Testing in a mouse model demonstrate that these motors can safely and rapidly neutralize gastric acid and simultaneously release payload without causing noticeable acute toxicity or affecting the stomach function, and the normal stomach pH is restored within 24 h post motor administration. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Radiation-induced increase in the release of amino acids by isolated, perfused skeletal muscle

International Nuclear Information System (INIS)

Schwenen, M.

1989-01-01

Local exposure of the hindquarter of the rat to 15Gy of gamma-radiation resulted, 4-6h after irradiation, in increased release of amino acids by the isolated, perfused hindquarter preparation, 70% of which is skeletal muscle. This increase in release involves not only alanine and glutamine, but also those amino acids not metabolized by muscle and, therefore, released in proportion to their occurrence in muscle proteins. Because metabolic parameters and content of energy-rich phosphate compounds in muscle remain unchanged, it is unlikely that general cellular damage is the underlying cause of the radiation-induced increase in amino acid release. The findings strongly favour the hypothesis that increased availability of amino acids results from enhanced protein break-down in skeletal muscle which has its onset shortly after irradiation. This radiation-induced disturbance in protein metabolism might be one of the pathogenetic factors in the aetiology of radiation myopathy. (author)

Inhibition of basophil histamine release by gangliosides. Further studies on the significance of cell membrane sialic acid in the histamine release process

DEFF Research Database (Denmark)

Jensen, C; Norn, S; Thastrup, Ole

1987-01-01

with the glucolipid mixture increased the sialic acid content of the cells, and this increase was attributed to an insertion of gangliosides into the cell membrane. The inhibition of histamine release was abolished by increasing the calcium concentration, which substantiates our previous findings that cell membrane......Histamine release from human basophils was inhibited by preincubation of the cells with a glucolipid mixture containing sialic acid-containing gangliosides. This was true for histamine release induced by anti-IgE, Concanavalin A and the calcium ionophore A23187, whereas the release induced by S....... aureus Wood 46 was not affected. It was demonstrated that the inhibitory capacity of the glucolipid mixture could be attributed to the content of gangliosides, since no inhibition was obtained with cerebrosides or with gangliosides from which sialic acid was removed. Preincubation of the cells...

Simultaneous Intercalation of 1-Naphthylacetic Acid and Indole-3-butyric Acid into Layered Double Hydroxides and Controlled Release Properties

Directory of Open Access Journals (Sweden)

Shifeng Li

2014-01-01

Full Text Available Controlled release formulations have been shown to have potential in overcoming the drawbacks of conventional plant growth regulators formulations. A controlled-release formulation of 1-naphthylacetic acid (NAA and indole-3-butyric acid (IBA simultaneous intercalated MgAl-layered double hydroxides (LDHs was prepared. The synthetic nanohybrid material was characterized by various techniques, and release kinetics was studied. NAA and IBA anions located in the gallery of MgAl-LDHs with bilayer arrangement, and the nanohybrids particles were of typical plate-like shape with the lateral size of 50–100 nm. The results revealed that NAA and IBA have been intercalated into the interlayer spaces of MgAl-LDHs. The release of NAA and IBA fits pseudo-second-order model and is dependent on temperature, pH value, and release medium. The nanohybrids of NAA and IBA simultaneously intercalated in LDHs possessed good controlled release properties.

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

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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

Ultrasound stimulated release of gallic acid from chitin hydrogel matrix

Energy Technology Data Exchange (ETDEWEB)

Jiang, Huixin; Kobayashi, Takaomi, E-mail: takaomi@nagaokaut.ac.jp

2017-06-01

Ultrasound (US) stimulated drug release was examined in this study using a chitin hydrogel matrix loaded with gallic acid (GA), a drug used for wound healing and anticancer. Using phase inversion, GA-chitin hydrogels were prepared from chitin-dimethylacetamide (DMAc)/lithium chloride (LiCl) solution in the presence of GA, with 24 h exposure of the solution to water vapor. The GA release from the GA-chitin hydrogel was examined under different US powers of 0–30 W at 43 kHz. The effects of GA loading amounts in the hydrogels (0.54, 0.43, and 0.25 mg/cm{sup 3}) and chitin concentrations (0.1, 0.5, and 1 wt%) on the release behaviors were recorded under 43 kHz US exposure at 30 W. Results show that US accelerated the release efficiencies for all samples. Furthermore, the release efficiency increased concomitantly with increasing US power, GA loading amount, and decrease of the chitin concentration. The highest release rate of 0.74 μg/mL·min was obtained from 0.54 mg/cm{sup 3} of GA-loaded hydrogel fabricated from a 0.1 wt% chitin mixture solution under 43 kHz US exposure at 30 W: nine times higher than that of the sample without US exposure. The hydrogel viscoelasticity demonstrated that the US irradiation rigidified the material. FT-IR showed that US can break the hydrogen bonds in the GA-chitin hydrogels. - Highlights: • Ultrasound (US) stimulated Gallic acid (GA) release from chitin hydrogel was studied. • The release efficiency of GA from chitin hydrogel increased nine times when irradiated by 43 kHz US compared with the sample without US. • Generalized 2D correlation and deconvolution study of FT-IR showed that US could promote the GA release by breaking hydrogen bonds.

Ultrasound stimulated release of gallic acid from chitin hydrogel matrix

International Nuclear Information System (INIS)

Jiang, Huixin; Kobayashi, Takaomi

2017-01-01

Ultrasound (US) stimulated drug release was examined in this study using a chitin hydrogel matrix loaded with gallic acid (GA), a drug used for wound healing and anticancer. Using phase inversion, GA-chitin hydrogels were prepared from chitin-dimethylacetamide (DMAc)/lithium chloride (LiCl) solution in the presence of GA, with 24 h exposure of the solution to water vapor. The GA release from the GA-chitin hydrogel was examined under different US powers of 0–30 W at 43 kHz. The effects of GA loading amounts in the hydrogels (0.54, 0.43, and 0.25 mg/cm 3 ) and chitin concentrations (0.1, 0.5, and 1 wt%) on the release behaviors were recorded under 43 kHz US exposure at 30 W. Results show that US accelerated the release efficiencies for all samples. Furthermore, the release efficiency increased concomitantly with increasing US power, GA loading amount, and decrease of the chitin concentration. The highest release rate of 0.74 μg/mL·min was obtained from 0.54 mg/cm 3 of GA-loaded hydrogel fabricated from a 0.1 wt% chitin mixture solution under 43 kHz US exposure at 30 W: nine times higher than that of the sample without US exposure. The hydrogel viscoelasticity demonstrated that the US irradiation rigidified the material. FT-IR showed that US can break the hydrogen bonds in the GA-chitin hydrogels. - Highlights: • Ultrasound (US) stimulated Gallic acid (GA) release from chitin hydrogel was studied. • The release efficiency of GA from chitin hydrogel increased nine times when irradiated by 43 kHz US compared with the sample without US. • Generalized 2D correlation and deconvolution study of FT-IR showed that US could promote the GA release by breaking hydrogen bonds.

Effects of dietary conjugated linoleic acid and linoleic:linolenic acid ratio on polyunsaturated fatty acid status in laying hens.

Science.gov (United States)

Du, M; Ahn, D U; Sell, J L

2000-12-01

A study was conducted to determine the effects of dietary conjugated linoleic acid (CLA) and the ratio of linoleic:linolenic acid on long-chain polyunsaturated fatty acid status. Thirty-two 31-wk-old White Leghorn hens were randomly assigned to four diets containing 8.2% soy oil, 4.1% soy oil + 2.5% CLA (4.1% CLA source), 4.1% flax oil + 2.5% CLA, or 4.1% soy oil + 4.1% flax oil. Hens were fed the diets for 3 wk before eggs and tissues were collected for the study. Lipids were extracted from egg yolk and tissues, classes of egg yolk lipids were separated, and fatty acid concentrations of total lipids, triglyceride, phosphatidylethanolamine, and phosphatidylcholine were analyzed by gas chromatography. The concentrations of monounsaturated fatty acids and non-CLA polyunsaturated fatty acids were reduced after CLA feeding. The amount of arachidonic acid was decreased after CLA feeding in linoleic acid- and linolenic acid-rich diets, but amounts of eicosapentaenoic acid and docosahexaenoic acid were increased in the linolenic-rich diet, indicating that the synthesis or deposition of long-chain n-3 fatty acids was accelerated after CLA feeding. The increased docosahexaenoic acid and eicosapentaenoic acid contents in lipid may be compensation for the decreased arachidonic acid content. Dietary supplementation of linoleic acid increased n-6 fatty acid levels in lipids, whereas linolenic acid increased n-3 fatty acid levels. Results also suggest that CLA might not be elongated to synthesize long-chain fatty acids in significant amounts. The effect of CLA in reducing the level of n-6 fatty acids and promoting the level of n-3 fatty acids could be related to the biological effects of CLA.

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

Directory of Open Access Journals (Sweden)

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.

Release of endothelial cell lipoprotein lipase by plasma lipoproteins and free fatty acids

International Nuclear Information System (INIS)

Saxena, U.; Witte, L.D.; Goldberg, I.J.

1989-01-01

Lipoprotein lipase (LPL) bound to the lumenal surface of vascular endothelial cells is responsible for the hydrolysis of triglycerides in plasma lipoproteins. Studies were performed to investigate whether human plasma lipoproteins and/or free fatty acids would release LPL which was bound to endothelial cells. Purified bovine milk LPL was incubated with cultured porcine aortic endothelial cells resulting in the association of enzyme activity with the cells. When the cells were then incubated with media containing chylomicrons or very low density lipoproteins (VLDL), a concentration-dependent decrease in the cell-associated LPL enzymatic activity was observed. In contrast, incubation with media containing low density lipoproteins or high density lipoproteins produced a much smaller decrease in the cell-associated enzymatic activity. The addition of increasing molar ratios of oleic acid:bovine serum albumin to the media also reduced enzyme activity associated with the endothelial cells. To determine whether the decrease in LPL activity was due to release of the enzyme from the cells or inactivation of the enzyme, studies were performed utilizing radioiodinated bovine LPL. Radiolabeled LPL protein was released from endothelial cells by chylomicrons, VLDL, and by free fatty acids (i.e. oleic acid bound to bovine serum albumin). The release of radiolabeled LPL by VLDL correlated with the generation of free fatty acids from the hydrolysis of VLDL triglyceride by LPL bound to the cells. Inhibition of LPL enzymatic activity by use of a specific monoclonal antibody, reduced the extent of release of 125 I-LPL from the endothelial cells by the added VLDL. These results demonstrated that LPL enzymatic activity and protein were removed from endothelial cells by triglyceride-rich lipoproteins (chylomicrons and VLDL) and oleic acid

Simulating the Fate and Transport of an Acid Mine Drainage Release

Science.gov (United States)

On August 5, 2015, approximately 3 million gallons of acid mine drainage were released from the Gold King Mine into Cement Creek in the San Juan River watershed (CO, NM, UT). The release further mobilized additional metals, which resulted in a large mass of solids and dissolved m...

Enhancement of nitric oxide release and hemocompatibility by surface chirality of D-tartaric acid grafting

Science.gov (United States)

Han, Honghong; Wang, Ke; Fan, Yonghong; Pan, Xiaxin; Huang, Nan; Weng, Yajun

2017-12-01

Nitric Oxide (NO) generation from endogenous NO-donors catalyzed by diselenide modified biomaterials has been reported. Here we reported surface chirality by L-tartaric acid and D-tartaric acid grafting on the outermost showed a significant impact on diselenide modified biomaterials, which modulated protein adsorption, NO release and anti-platelet adhesion properties. D-tartaric acid grafted surface showed more blood protein adsorption than that of L-surfaces by QCM analysis, however, ELISA analysis disclosed less fibrinogen denatured on the D surfaces. Due to the surface ratio of selenium decreasing, NO release catalyzed by L-tartaric acid grafting on the outermost significantly decreased in comparison to that of only selenocystamine immobilized surfaces. While NO release catalyzed by D-tartaric acid grafting on the outermost didn't decrease and was similar with that of selenocystamine immobilized surfaces. Surface chirality combined with NO release had synergetic effects on platelet adhesion, and it showed the lowest number of platelets adhered on the D-tartaric acid grafted surfaces. Thus surface chirality from D-tartaric acid grafting enhanced hemocompatibility of the surface in this study. Our work provides new insights into engineering novel blood contacting biomaterials by taking into account surface chirality.

Omega 3 fatty acids increase spontaneous release of cytosolic components from tumor cells

International Nuclear Information System (INIS)

Jenski, L.J.; Sturdevant, L.K.; Ehringer, W.D.; Stillwell, W.

1991-01-01

Mice fed menhaden (fish) oil or coconut oil-rich diets were inoculated intraperitoneally with a rapidly growing leukemia, T27A. After one week, the tumor cells were harvested, and 51Cr was used to label intracellular molecules. Spontaneous release of 51Cr was used as a measure of plasma membrane permeability. Compared to cells from mice fed coconut oil (rich in saturated fatty acids), tumor cells from mice fed menhaden oil (rich in long chain polyunsaturated omega 3 fatty acids) showed an increased level of spontaneous 51Cr release, which was exacerbated by increased temperature and reduced by extracellular protein. At physiological salt concentrations, the released 51Cr was detected in particles of approximately 2700 daltons. Enhanced permeability correlated with the incorporation of dietary (fish oil) omega 3 polyunsaturated fatty acids docosahexaenoic and eicosapentaenoic acid into the tumor cells. The results demonstrate that omega 3 fatty acids are incorporated into cellular constituents of tumor cells and change properties associated with the plasma membrane. This result suggests that dietary manipulation may be used to enhance tumor cell permeability and contribute to tumor eradication

Production of ascorbic acid releasing biomaterials for pelvic floor repair.

Science.gov (United States)

Mangır, Naşide; Bullock, Anthony J; Roman, Sabiniano; Osman, Nadir; Chapple, Christopher; MacNeil, Sheila

2016-01-01

An underlying abnormality in collagen turnover is implied in the occurrence of complications and recurrences after mesh augmented pelvic floor repair surgeries. Ascorbic acid is a potent stimulant of collagen synthesis. The aim of this study is to produce ascorbic acid releasing poly-lactic acid (PLA) scaffolds and evaluate them for their effects on extracellular matrix production and the strength of the materials. Scaffolds which contained either l-ascorbic acid (AA) and Ascorbate-2-Phosphate (A2P) were produced with emulsion electrospinning. The release of both drugs was measured by UV spectrophotometry. Human dermal fibroblasts were seeded on scaffolds and cultured for 2weeks. Cell attachment, viability and total collagen production were evaluated as well as mechanical properties. No significant differences were observed between AA, A2P, Vehicle and PLA scaffolds in terms of fibre diameter and pore size. The encapsulation efficiency and successful release of both AA and A2P were demonstrated. Both AA and A2P containing scaffolds were significantly more hydrophilic and stronger in both dry and wet states compared to PLA scaffolds. Fibroblasts produced more collagen on scaffolds containing either AA or A2P compared to cells grown on control scaffolds. This study is the first to directly compare the two ascorbic acid derivatives in a tissue engineered scaffold and shows that both AA and A2P releasing electrospun PLA scaffolds increased collagen production of fibroblasts to similar extents but AA scaffolds seemed to be more hydrophilic and stronger compared to A2P scaffolds. Mesh augmented surgical repair of the pelvic floor currently relies on non-degradable materials which results in severe complications in some patients. There is an unmet and urgent need for better pelvic floor repair materials. Our current understanding suggests that the ideal material should be able to better integrate into sites of implantation both biologically and mechanically. The impact of

Safflower and olive oil dietary treatments rescue aberrant embryonic arachidonic acid and nitric oxide metabolism and prevent diabetic embryopathy in rats.

Science.gov (United States)

Higa, R; White, V; Martínez, N; Kurtz, M; Capobianco, E; Jawerbaum, A

2010-04-01

Aberrant arachidonic acid and nitric oxide (NO) metabolic pathways are involved in diabetic embryopathy. Previous works have found diminished concentrations of PGE(2) and PGI(2) in embryos from diabetic rats, and that PGI(2) is capable of increasing embryonic PGE(2) concentrations through the activation of the nuclear receptor PPARdelta. PPARdelta activators are lipid molecules such as oleic and linoleic acids, present in high concentrations in olive and safflower oils, respectively. The aim of this study was to analyze the capability of dietary supplementation with either 6% olive or 6% safflower oils to regulate PGE(2), PGI(2) and NO concentrations in embryos and deciduas from control and diabetic rats during early organogenesis. Diabetes was induced by a single injection of streptozotocin (55 mg/kg) 1 week before mating. Animals were fed with the oil-supplemented diets from Days 0.5 to 10.5 of gestation. PGI(2) and PGE(2) were measured by EIA and NO through the evaluation of its stable metabolites nitrates-nitrites in 10.5 day embryos and deciduas. We found that the olive and safflower oil-supplemented treatments highly reduced resorption and malformation rates in diabetic animals, and that they were able to prevent maternal diabetes-induced alterations in embryonic and decidual PGI(2) and PGE(2) concentrations. Moreover, these dietary treatments prevented NO overproduction in embryos and deciduas from diabetic rats. These data indicate that in maternal diabetes both the embryo and the decidua benefit from the olive and safflower oil supplementation probably through mechanisms that involve the rescue of aberrant prostaglandin and NO generation and that prevent developmental damage during early organogenesis.

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

International Nuclear Information System (INIS)

Hallaq, H.; Leaf, A.; Sellmayer, A.; Smith, T.W.

1990-01-01

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 μM 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 μM eicosapentaenoic acid completely prevented the toxic effects of ouabain at 0.1 mM. No differences in bumetanide-inhibitable 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 ± 29 and 757 ± 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

Liver conversion of docosahexaenoic and arachidonic acids from their 18-carbon precursors in rats on a DHA-free but α-LNA-containing n-3 PUFA adequate diet.

Science.gov (United States)

Gao, Fei; Kim, Hyung-Wook; Igarashi, Miki; Kiesewetter, Dale; Chang, Lisa; Ma, Kaizong; Rapoport, Stanley I

2011-01-01

The long-chain polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA, 20:5n-3), docosahexaenoic acid (DHA, 22:6n-3), and arachidonic acid (AA, 20:4n-6), are critical for health. These PUFAs can be synthesized in liver from their plant-derived precursors, α-linolenic acid (α-LNA, 18:3n-3) and linoleic acid (LA, 18:2n-6). Vegetarians and vegans may have suboptimal long-chain n-3 PUFA status, and the extent of the conversion of α-LNA to EPA and DHA by the liver is debatable. We quantified liver conversion of DHA and other n-3 PUFAs from α-LNA in rats fed a DHA-free but α-LNA (n-3 PUFA) adequate diet, and compared results to conversion of LA to AA. [U-(13)C]LA or [U-(13)C]α-LNA was infused intravenously for 2h at a constant rate into unanesthetized rats fed a DHA-free α-LNA adequate diet, and published equations were used to calculate kinetic parameters. The conversion coefficient k(⁎) of DHA from α-LNA was much higher than for AA from LA (97.2×10(-3) vs. 10.6×10(-3)min(-1)), suggesting that liver elongation-desaturation is more selective for n-3 PUFA biosynthesis on a per molecule basis. The net daily secretion rate of DHA, 20.3μmol/day, exceeded the reported brain DHA consumption rate by 50-fold, suggesting that the liver can maintain brain DHA metabolism with an adequate dietary supply solely of α-LNA. This infusion method could be used in vegetarians or vegans to determine minimal daily requirements of EPA and DHA in humans. Published by Elsevier B.V.

[Shikimic acid inhibits the degranulation and histamine release in RBL-2H3 cells].

Science.gov (United States)

Chen, Xianyong; Zheng, Qianqian; Liu, Wei; Yu, Lingling; Wang, Jinling; Li, Shigang

2017-05-01

Objective To study the effects of shikimic acid on the proliferation of rat RBL-2H3 cells and the degranulation of the cells induced by C48/80 and its mechanism. Methods MTT assay was performed to measure the proliferation of RBL-2H3 cells treated with 3, 10, 30 μg/mL shikimic acid. Toluidine blue staining was used to observe the degranulation of RBL-2H3 cells. The release of β-hexosaminidase from RBL-2H3 cells treated with 0, 12.5, 25, 50, 80, 100 μg/mL C48/80 was determined by substrate assay. ELISA was used to detect the histamine content in the supernatant of each treated group. Results Shikimic acid at 3, 10, 300 μg/mL had no obvious inhibitory effect on the proliferation of RBL-2H3 cells. There was a dose-effect relationship between the degranulation of RBL-2H3 cells and C48/80 concentration. Shikimic acid inhibited the degranulation of RBL-2H3 cells compared with the positive control group, the β-hexosaminidase release rate and histamine release were significantly reduced in RBL-2H3 cells treated with shikimic acid and C48/80. Conclusion Shikimic acid can inhibit the degranulation of RBL-2H3 cells and reduce histamine release.

Docosahexaenoic acid and other fatty acids induce a decrease in pHi in Jurkat T-cells

OpenAIRE

Aires, Virginie; Hichami, Aziz; Moutairou, Kabirou; Khan, Naim Akhtar

2003-01-01

Docosahexaenoic acid (DHA) induced rapid (t1/2=33 s) and dose-dependent decreases in pHi in BCECF-loaded human (Jurkat) T-cells. Addition of 5-(N,N-dimethyl)-amiloride, an inhibitor of Na+/H+ exchanger, prolonged DHA-induced acidification as a function of time, indicating that the exchanger is implicated in pHi recovery.Other fatty acids like oleic acid, arachidonic acid, eicosapentaenoic acid, but not palmitic acid, also induced a fall in pHi in these cells.To assess the role of calcium in t...

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

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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. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

Omega-6 and trans fatty acids in blood cell membranes: a risk factor for acute coronary syndromes?

Science.gov (United States)

Block, Robert C; Harris, William S; Reid, Kimberly J; Spertus, John A

2008-12-01

Although fatty acid intake has been associated with risk of coronary disease events, the association between blood omega-6 and trans fatty acids (FAs) at the time of an acute coronary syndrome (ACS) is unknown. The relationship of blood FA composition to ACS was analyzed in 768 incident cases and 768 controls (matched on age, sex, and race). Compared to controls, ACS cases' blood cell membrane content of linoleic acid was 13% lower (P 3 times the odds for being a case (odds ratio [OR] 3.23, 95% confidence interval [CI] 2.63-4.17). The relationship of arachidonic acid to ACS was U shaped; compared to the first quartile of arachidonic acid, the ORs for case status in the second, third, and fourth quartiles were 0.73 (95% CI 0.47-1.13), 0.65 (95% CI 0.41-1.04), and 2.32 (95% CI 1.39-3.90), respectively. The OR for a 1-SD increase in trans oleic acid was 1.24 (95% CI 1.06-1.45), and for trans-trans linoleic acid, 1.1 (95% CI 0.93-1.30). All associations were independent of membrane omega-3 FA content. High blood levels of linoleic acid but low levels of trans oleic acid are inversely associated with ACS. The relationship of arachidonic acid to ACS appears more complex.

Biowaiver Monographs for Immediate-Release Solid Oral Dosage Forms: Folic Acid.

Science.gov (United States)

Hofsäss, Martin A; Souza, Jacqueline de; Silva-Barcellos, Neila M; Bellavinha, Karime R; Abrahamsson, Bertil; Cristofoletti, Rodrigo; Groot, D W; Parr, Alan; Langguth, Peter; Polli, James E; Shah, Vinod P; Tajiri, Tomokazu; Mehta, Mehul U; Dressman, Jennifer B

2017-12-01

This work presents a review of literature and experimental data relevant to the possibility of waiving pharmacokinetic bioequivalence studies in human volunteers for approval of immediate-release solid oral pharmaceutical forms containing folic acid as the single active pharmaceutical ingredient. For dosage forms containing 5 mg folic acid, the highest dose strength on the World Health Organization Essential Medicines List, the dose/solubility ratio calculated from solubility studies was higher than 250 mL, corresponding to a classification as "not highly soluble." Small, physiological doses of folic acid (≤320 μg) seem to be absorbed completely via active transport, but permeability data for higher doses of 1-5 mg are inconclusive. Following a conservative approach, folic acid is classified as a Biopharmaceutics Classification System class IV compound until more reliable data become available. Commensurate with its solubility characteristics, the results of dissolution studies indicated that none of the folic acid products evaluated showed rapid dissolution in media at pH 1.2 or 4.5. Therefore, according to the current criteria of the Biopharmaceutics Classification System, the biowaiver approval procedure cannot be recommended for immediate-release solid oral dosage forms containing folic acid. Copyright © 2017 American Pharmacists Association®. All rights reserved.

Characterization of arachidonate 5-lipoxygenase and leukotriene A4 synthetase from RBL-1 cells

International Nuclear Information System (INIS)

Cook, M.; Hogaboom, G.K.; Sarau, H.M.; Foley, J.J.; Crooke, S.T.

1986-01-01

5-lipoxygenase (LO) and leukotriene (LT) A4 synthetase from RBL-1 high speed (105,000 x g for 60 min) supernatants were partially purified by protein-high performance liquid chromatography (HPLC) and characterized in detail. The partially purified preparation contained only 5-LO and LTA4 synthetase and was isolated from 12-LO, peroxidase and LTA4 hydrolase activities. Reaction products were separated by reversed phase HPLC and quantitated by absorption spectrophotometry and radiochemical detection. The enzyme preparation rapidly converted [ 14 C]arachidonate to [ 14 C]5-hydroperoxyeicosatetraenoic acid (HPETE) and [ 14 C]5,12-dihydroperoxyeicosatetraenoic acids (diHETEs). The 5,12-diHETEs were primarily non-enzymatic breakdown products of LTA4 (e.g., 6-trans-LTB4 and 6-trans-12-epi-LTB4). Both the 5-LO and LTA4 synthetase activities were Ca 2+- and ATP-dependent. For both enzyme activities, the CA 2+ stimulation required the presence of ATP. The fatty acid hydroperoxides, 5-,12-, and 15-HPETE, both stimulated ([ 3 μM]) 5-LO and LTA4 synthetase activities. The rapid isolation and subsequent characterization of 5-LO and LTA4 synthetase provide the bases for the further understanding of the role of the LO pathway in biological processes

Ursodeoxycholic acid inhibits TNFα-induced IL-8 release from monocytes.

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O'Dwyer, Aoife M; Lajczak, Natalia K; Keyes, Jennifer A; Ward, Joseph B; Greene, Catherine M; Keely, Stephen J

2016-08-01

Monocytes are critical to the pathogenesis of inflammatory bowel disease (IBD) as they infiltrate the mucosa and release cytokines that drive the inflammatory response. Ursodeoxycholic acid (UDCA), a naturally occurring bile acid with anti-inflammatory actions, has been proposed as a potential new therapy for IBD. However, its effects on monocyte function are not yet known. Primary monocytes from healthy volunteers or cultured U937 monocytes were treated with either the proinflammatory cytokine, TNFα (5 ng/ml) or the bacterial endotoxin, lipopolysaccharide (LPS; 1 μg/ml) for 24 h, in the absence or presence of UDCA (25-100 μM). IL-8 release into the supernatant was measured by ELISA. mRNA levels were quantified by qPCR and changes in cell signaling proteins were determined by Western blotting. Toxicity was assessed by measuring lactate dehydrogenase (LDH) release. UDCA treatment significantly attenuated TNFα-, but not LPS-driven, release of IL-8 from both primary and cultured monocytes. UDCA inhibition of TNFα-driven responses was associated with reduced IL-8 mRNA expression. Both TNFα and LPS stimulated NFκB activation in monocytes, while IL-8 release in response to both cytokines was attenuated by an NFκB inhibitor, BMS-345541. Interestingly, UDCA inhibited TNFα-, but not LPS-stimulated, NFκB activation. Finally, TNFα, but not LPS, induced phosphorylation of TNF receptor associated factor (TRAF2), while UDCA cotreatment attenuated this response. We conclude that UDCA specifically inhibits TNFα-induced IL-8 release from monocytes by inhibiting TRAF2 activation. Since such actions would serve to dampen mucosal immune responses in vivo, our data support the therapeutic potential of UDCA for IBD. Copyright © 2016 the American Physiological Society.

Selective remodeling of cardiolipin fatty acids in the aged rat heart

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Rapoport Stanley I

2006-01-01

Full Text Available Abstract Background The heart is rich in cardiolipin, a phospholipid acylated in four sites, predominately with linoleic acid. Whether or not aging alters the composition of cardiolipin acyl chains is controversial. We therefore measured the fatty acid concentration of cardiolipin in hearts of 4, 12 and 24 month old rats that consumed one diet, adequate in fatty acids for the duration of their life. Results The concentration (nmol/g of linoleic acid was decreased in 24 month old rats (3965 ± 617, mean ± SD vs 4 month old rats (5525 ± 656, while the concentrations of arachidonic and docosahexaenoic acid were increased in 24 month old rats (79 ± 9 vs 178 ± 27 and 104 ± 16 vs 307 ± 68 for arachidonic and docosahexaenoic acids, 4 months vs 24 months, respectively. Similar changes were not observed in ethanolamine glycerophospholipids or plasma unesterified fatty acids, suggesting specificity of these effects to cardiolipin. Conclusion These results demonstrate that cardiolipin remodeling occurs with aging, specifically an increase in highly unsaturated fatty acids.

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...

Prolonged local anesthetic action through slow release from poly (lactic acid co castor oil).

Science.gov (United States)

Sokolsky-Papkov, Marina; Golovanevski, Ludmila; Domb, Abraham J; Weiniger, Carolyn F

2009-01-01

To evaluate a new formulation of bupivacaine loaded in an injectable fatty acid based biodegradable polymer poly(lactic acid co castor oil) in prolonging motor and sensory block when injected locally. The polyesters were synthesized from DL: -lactic acid and castor oil with feed ratio of 4:6 and 3:7 w/w. Bupivacaine was dispersed in poly(fatty ester) liquid and tested for drug release in vitro. The polymer p(DLLA:CO) 3:7 loaded with 10% bupivacaine was injected through a 22G needle close to the sciatic nerve of ICR mice and the duration of sensory and motor nerve blockade was measured. The DL: -lactic acid co castor oil p(DLLA:CO) 3:7 released 65% of the incorporated bupivacaine during 1 week in vitro. Single injection of 10% bupivacaine loaded into this polymer caused motor block that lasted 24 h and sensory block that lasted 48 h. Previously we developed a ricinoleic acid based polymer with incorporated bupivacaine which prolonged anesthesia to 30 h. The new polymer poly(lactic acid co castor oil) 3:7 provides slow release of effective doses of the incorporated local anesthetic agent and prolongs anesthesia to 48 h.

In Vitro Investigation of Self-Assembled Nanoparticles Based on Hyaluronic Acid-Deoxycholic Acid Conjugates for Controlled Release Doxorubicin: Effect of Degree of Substitution of Deoxycholic Acid

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Wen-Hao Wei

2015-03-01

Full Text Available Self-assembled nanoparticles based on a hyaluronic acid-deoxycholic acid (HD chemical conjugate with different degree of substitution (DS of deoxycholic acid (DOCA were prepared. The degree of substitution (DS was determined by titration method. The nanoparticles were loaded with doxorubicin (DOX as the model drug. The human cervical cancer (HeLa cell line was utilized for in vitro studies and cell cytotoxicity of DOX incorporated in the HD nanoparticles was accessed by the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. In addition, cellular uptake of fluorescently labeled nanoparticles was also investigated. An increase in the degree of deoxycholic acid substitution reduced the size of the nanoparticles and also enhanced their drug encapsulation efficiency (EE, which increased with the increase of DS. A higher degree of deoxycholic acid substitution also lead to a lower release rate and an initial burst release of doxorubicin from the nanoparticles. In summary, the degree of substitution allows the modulation of the particle size, drug encapsulation efficiency, drug release rate, and cell uptake efficiency of the nanoparticles. The herein developed hyaluronic acid-deoxycholic acid conjugates are a good candidate for drug delivery and could potentiate therapeutic formulations for doxorubicin–mediated cancer therapy.

Chronic sucrose intake decreases concentrations of n6 fatty acids, but not docosahexaenoic acid in the rat brain phospholipids.

Science.gov (United States)

Mašek, Tomislav; Starčević, Kristina

2017-07-13

We investigated the influence of high sucrose intake, administered in drinking water, on the lipid profile of the brain and on the expression of SREBP1c and Δ-desaturase genes. Adult male rats received 30% sucrose solution for 20 weeks (Sucrose group), or plain water (Control group). After the 20th week of sucrose treatment, the Sucrose group showed permanent hyperglycemia. Sucrose treatment also increased the amount of total lipids and fatty acids in the brain. The brain fatty acid profile of total lipids as well as phosphatidylethanolamine, phosphatidylcholine and cardiolipin of the Sucrose group was extensively changed. The most interesting change was a significant decrease in n6 fatty acids, including the important arachidonic acid, whereas the content of oleic and docosahexaenoic acid remained unchanged. RT-qPCR revealed an increase in Δ-5-desaturase and SREBP1c gene expression. In conclusion, high sucrose intake via drinking water extensively changes rat brain fatty acid profile by decreasing n6 fatty acids, including arachidonic acid. In contrast, the content of docosahexaenoic acid remains constant in the brain total lipids as well as in phospholipids. Changes in the brain fatty acid profile reflect changes in the lipid metabolism of the rat lipogenic tissues and concentrations in the circulation. Copyright © 2017 Elsevier B.V. All rights reserved.

n-3 fatty acids reduce plasma 20-hydroxyeicosatetraenoic acid and blood pressure in patients with chronic kidney disease.

Science.gov (United States)

Barden, Anne E; Burke, Valerie; Mas, Emilie; Beilin, Lawrence J; Puddey, Ian B; Watts, Gerald F; Irish, Ashley B; Mori, Trevor A

2015-09-01

Metabolism of arachidonic acid by cytochrome P450 ω-hydroxylase leads to the formation of 20-hydroxyeicosatetraenoic acid (20-HETE) that regulates vascular function, sodium homeostasis and blood pressure (BP). Supplementation with n-3 fatty acids is known to alter arachidonic acid metabolism and reduce the formation of the lipid peroxidation products F2-isoprostanes, but the effect of n-3 fatty acids on 20-HETE has not been studied. We previously reported a significant effect of n-3 fatty acids but not coenzyme Q10 (CoQ) to reduce BP in a double-blind, placebo-controlled intervention, wherein patients with chronic kidney disease (CKD) were randomized to n-3 fatty acids (4 g), CoQ (200 mg), both supplements or control (4 g olive oil), daily for 8 weeks. This study examined the effect of n-3 fatty acids on plasma and urinary 20-HETE in the same study, as well as plasma and urinary F2-isoprostanes, and relate these to changes in BP. Seventy-four patients completed the 8-week intervention. n-3 fatty acids but not CoQ significantly reduced plasma 20-HETE (P = 0.001) and F2-isoprostanes (P fatty acids. This is the first report that n-3 fatty acid supplementation reduces plasma 20-HETE in humans and that this associates with reduced BP. These results provide a plausible mechanism for the reduction in BP observed in patients with CKD following n-3 fatty acid supplementation.

Endothelium-derived vasoactive factors and hypertension: possible roles in pathogenesis and as treatment targets

DEFF Research Database (Denmark)

Félétou, Michel; Köhler, Ralf; Vanhoutte, Paul M

2010-01-01

Endothelial cells regulate vascular tone by releasing various contracting and relaxing factors including nitric oxide (NO), arachidonic acid metabolites (derived from cyclooxygenases, lipoxygenases, and cytochrome P450 monooxygenases), reactive oxygen species, and vasoactive peptides. Additionally...

[Effect of glucocorticoides on the release of amino acids in the perfused rat hindquarter (author's transl)].

Science.gov (United States)

Thienhaus, R; Tharandt, L; Zais, U; Staib, W

1975-06-01

The release of amino acids by skeletal muscle was studied in the isolated perfused rat hindquarter. Adrenalectomy depressed the formation of glutamine and alanine as well as the efflux of all other amino acids measured. Betamethasone--a synthetic glucocorticoid--caused a significant increase in the efflux of nearly all amino acids up to the level of normal controls. The release of amino acids was also increased in perfused hindquarters of diabetic rats. On the other hand, insulin exhibited a depressing effect on the release of amino acids by hindquarters of normal rats. The metabolic integrity of the muscle tissue was proved by measuring creatine phosphate, ATP, ADP and water content as well as by the significant insulin effect on glucose uptake and on [14C]leucine incorporation into muscle proteins.

Controlled Release of 5-Aminosalicylic Acid (5-ASA from New Biodegradable Polyurethanes

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El-Refaie Kenawy

2010-03-01

Full Text Available Segmented polyurethanes containing azo aromatic groups in the main chain were synthesized by reaction of 3,3'-azobis(6-hydroxybenzoic acid (ABHB, 5-[4-(hydroxyphenylazo] salicylic acid (HPAS, and 5-[1-hydroxynaphthylazo] salicylic acid (HNAS with hexamethylenediisocyanate (HDI. All synthesized monomers and polymers were characterized by elemental analysis, FTIR, 1H-NMR spectra, TGA and DSC analysis. All the synthesized azo polymers showed good thermal stability and the onset decomposition temperature of all these polymers was found to be above 195 ºC under nitrogen atmosphere.The release of 5-ASA under physiological conditions (pH = 7.8 and pH = 1.5 was investigated at body temperature (37 ºC. The release rate of 5-ASA increased with increasing pH (i.e., 7.8 > 1.5.

Characterisation of (R-2-(2-Fluorobiphenyl-4-yl-N-(3-Methylpyridin-2-ylPropanamide as a Dual Fatty Acid Amide Hydrolase: Cyclooxygenase Inhibitor.

Directory of Open Access Journals (Sweden)

Sandra Gouveia-Figueira

Full Text Available Increased endocannabinoid tonus by dual-action fatty acid amide hydrolase (FAAH and substrate selective cyclooxygenase (COX-2 inhibitors is a promising approach for pain-relief. One such compound with this profile is 2-(2-fluorobiphenyl-4-yl-N-(3-methylpyridin-2-ylpropanamide (Flu-AM1. These activities are shown by Flu-AM1 racemate, but it is not known whether its two single enantiomers behave differently, as is the case towards COX-2 for the parent flurbiprofen enantiomers. Further, the effects of the compound upon COX-2-derived lipids in intact cells are not known.COX inhibition was determined using an oxygraphic method with arachidonic acid and 2-arachidonoylglycerol (2-AG as substrates. FAAH was assayed in mouse brain homogenates using anandamide (AEA as substrate. Lipidomic analysis was conducted in unstimulated and lipopolysaccharide + interferon γ- stimulated RAW 264.7 macrophage cells. Both enantiomers inhibited COX-2 in a substrate-selective and time-dependent manner, with IC50 values in the absence of a preincubation phase of: (R-Flu-AM1, COX-1 (arachidonic acid 6 μM; COX-2 (arachidonic acid 20 μM; COX-2 (2-AG 1 μM; (S-Flu-AM1, COX-1 (arachidonic acid 3 μM; COX-2 (arachidonic acid 10 μM; COX-2 (2-AG 0.7 μM. The compounds showed no enantiomeric selectivity in their FAAH inhibitory properties. (R-Flu-AM1 (10 μM greatly inhibited the production of prostaglandin D2 and E2 in both unstimulated and lipopolysaccharide + interferon γ- stimulated RAW 264.7 macrophage cells. Levels of 2-AG were not affected either by (R-Flu-AM1 or by 10 μM flurbiprofen, either alone or in combination with the FAAH inhibitor URB597 (1 μM.Both enantiomers of Flu-AM1 are more potent inhibitors of 2-AG compared to arachidonic acid oxygenation by COX-2. Inhibition of COX in lipopolysaccharide + interferon γ- stimulated RAW 264.7 cells is insufficient to affect 2-AG levels despite the large induction of COX-2 produced by this treatment.

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...... randomly selected groups of 62 Faroese and 37 Danish women with an assessable gestational age. Average ratio of long-chain n-3 fatty acids to arachidonic acid [(3/6) ratio] was 0.73 (SD = 0.11) in Faroese women and 0.61 (SD = 0.12) in Danish women (p ...-3 fatty acids in the Faroes. A 20% increase in the (3/6) ratio was associated with an increase in pregnancy duration of 5.7 days in Danish women (95% confidence interval, 1.4 to 10.1 days; p = 0.02) and 0.7 days in Faroese women (95% confidence interval, -2.0 to 3.3; p = 0.6). The hypothesized...

FATTY ACID COMPOSITION AND PROSTAGLANDIN CONTENT OF THE RED SEAWEED Gracilaria sp. FROM INDONESIA

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Muhammad Ikbal Illijas

2012-06-01

Full Text Available High content of polyunsaturated fatty acids (PUFAs such as arachidonic and eicosapentaenoic acids are typical for the red alga. Analysis of fatty acid composition and prostaglandin content was conducted in the red alga Gracilaria sp. from Indonesia. Total lipid of the alga was extracted with CHCl3-MeOH (2:1, v/v. Analysis of the fatty acids composition was performed on gas chromatography (GC equipped with omega wax column (30 m x 0,32 mm i.d., Supelco, PA, USA and analysis of prostaglandins were carried out by HPLC on ODS column (Mightysil RP-18 GP, 250 mm x 4.6 mm, 5 μm. The content of fatty acids high for were palmitic acid (50% and arachidonic acid (26.9%, whereas prostaglandin E2 was identified and found lower concentration (44.2 μg/gram total lipid.

Uranium Release from Acidic Weathered Hanford Sediments: Single-Pass Flow-Through and Column Experiments.

Science.gov (United States)

Wang, Guohui; Um, Wooyong; Wang, Zheming; Reinoso-Maset, Estela; Washton, Nancy M; Mueller, Karl T; Perdrial, Nicolas; O'Day, Peggy A; Chorover, Jon

2017-10-03

The reaction of acidic radioactive waste with sediments can induce mineral transformation reactions that, in turn, control contaminant fate. Here, sediment weathering by synthetic uranium-containing acid solutions was investigated using bench-scale experiments to simulate waste disposal conditions at Hanford's cribs (Hanford, WA). During acid weathering, the presence of phosphate exerted a strong influence over uranium mineralogy and a rapidly precipitated, crystalline uranium phosphate phase (meta-ankoleite [K(UO 2 )(PO 4 )·3H 2 O]) was identified using spectroscopic and diffraction-based techniques. In phosphate-free system, uranium oxyhydroxide minerals such as K-compreignacite [K 2 (UO 2 ) 6 O 4 (OH) 6 ·7H 2 O] were formed. Single-pass flow-through (SPFT) and column leaching experiments using synthetic Hanford pore water showed that uranium precipitated as meta-ankoleite during acid weathering was strongly retained in the sediments, with an average release rate of 2.67 × 10 -12 mol g -1 s -1 . In the absence of phosphate, uranium release was controlled by dissolution of uranium oxyhydroxide (compreignacite-type) mineral with a release rate of 1.05-2.42 × 10 -10 mol g -1 s -1 . The uranium mineralogy and release rates determined for both systems in this study support the development of accurate U-release models for the prediction of contaminant transport. These results suggest that phosphate minerals may be a good candidate for uranium remediation approaches at contaminated sites.

Uranium Release from Acidic Weathered Hanford Sediments: Single-Pass Flow-Through and Column Experiments

Energy Technology Data Exchange (ETDEWEB)

Wang, Guohui [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Um, Wooyong [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Pohang University of Science and Technology (POSTECH), Pohang, South Korea; Wang, Zheming [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Reinoso-Maset, Estela [Sierra; Washton, Nancy M. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Mueller, Karl T. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Perdrial, Nicolas [Department; Department; O’Day, Peggy A. [Sierra; Chorover, Jon [Department

2017-09-21

The reaction of acidic radioactive waste with sediments can induce mineral transformation reactions that, in turn, control contaminant fate. Here, sediment weathering by synthetic uranium-containing acid solutions was investigated using bench-scale experiments to simulate waste disposal conditions at Hanford’s cribs, USA. During acid weathering, the presence of phosphate exerted a strong influence over uranium mineralogy and a rapidly precipitated, crystalline uranium phosphate phase (meta-ankoleite [K(UO2)(PO4)·3H2O]) was identified using spectroscopic and diffraction-based techniques. In phosphate-free system, uranium oxyhydroxide minerals such as K-compreignacite [K2(UO2)6O4(OH)6·7H2O] were formed. Single-pass flow-through (SPFT) and column leaching experiments using synthetic Hanford pore water showed that uranium precipitated as meta-ankoleite during acid weathering was strongly retained in the sediments, with an average release rate of 2.67E-12 mol g-1 s-1. In the absence of phosphate, uranium release was controlled by dissolution of uranium oxyhydroxide (compreignacite-type) mineral with a release rate of 1.05-2.42E-10 mol g-1 s-1. The uranium mineralogy and release rates determined for both systems in this study support the development of accurate U-release models for prediction of contaminant transport. These results suggest that phosphate minerals may be a good candidate for uranium remediation approaches at contaminated sites.

Liquid-Phase Heat-Release Rates of the Systems Hydrazine-Nitric Acid and Unsymmetrical Dimethylhydrazine-Nitric Acid

Science.gov (United States)

Somogyi, Dezso; Feiler, Charles E.

1960-01-01

The initial rates of heat release produced by the reactions of hydrazine and unsymmetrical dimethylhydrazine with nitric acid were determined in a bomb calorimeter under conditions of forced mixing. Fuel-oxidant weight ratio and injection velocity were varied. The rate of heat release apparently depended on the interfacial area between the propellants. Above a narrow range of injection velocities representing a critical amount of interfacial area, the rates reached a maximum and were almost constant with injection velocity. The maximum rate for hydrazine was about 70 percent greater than that for unsymmetrical dimethylhydrazine. The total heat released did not vary with mixture ratio over the range studied.

Dietary Linoleic and a-Linolenic Acid Affect Anxiety-Related Responses and Exploratory Activity in Growing Pigs

NARCIS (Netherlands)

Clouard, C.M.; Gerrits, W.J.J.; Kerkhof, van I.; Smink, W.; Bolhuis, J.E.

2015-01-01

Background: Growing evidence suggests that the dietary ratio of linoleic acid (LA) to a-linolenic acid (ALA), the precursors of arachidonic acid (AA) and docosahexaenoic acid (DHA), respectively, may affect behavior in mammals. Objective: This study aimed at evaluating the impact of dietary LA and

Time-related fatty acid profiles of plasma and lymph after gastric administration of fats to rats fed high-fat diets

DEFF Research Database (Denmark)

Porsgaard, Trine; Straarup, E. M.; Brand, C. L.

2000-01-01

investigated. Although decreasing during the early absorptive phase a continuous contribution of endogenous trans-C18:I and arachidonic acid was observed in plasma. Small differences were observed between the 4 dietary fats. In lymph, the transport of trans-C18:1 rose markedly after butter administration...... partly caused by the content of this fatty acid in butter, while the transport of trans-C18:1 after R/C10 was unchanged although still transported at a reasonable high rate. The transport of arachidonic acid increased after administration of both butter and R/C10. Minor changes were observed in plasma...

Suppression of Remodeling Behaviors with Arachidonic Acid Modification for Enhanced in vivo Antiatherogenic Efficacies of Lovastatin-loaded Discoidal Recombinant High Density Lipoprotein.

Science.gov (United States)

He, Hongliang; Zhang, Mengyuan; Liu, Lisha; Zhang, Shuangshuang; Liu, Jianping; Zhang, Wenli

2015-10-01

A series of in vitro evaluation in our previous studies had proved that arachidonic acid (AA) modification could suppress the remodeling behaviors of lovastatin-loaded discoidal reconstituted high density lipoprotein (LT-d-rHDL) by restraining the reactivity with lecithin cholesterol acyltransferase (LCAT) for reducing undesired drug leakage. This study focuses on the investigation of AA-modified LT-d-rHDL (AA-LT-d-rHDL) in atherosclerotic New Zealand White (NZW) rabbit models to explore whether AA modification could enhance drug targeting delivery and improve antiatherogenic efficacies in vivo. After pharmacokinetics of AA-LT-d-rHDL modified with different AA amount were investigated in atherosclerotic NZW rabbits, atherosclerotic lesions targeting property was assessed by ex vivo imaging of aortic tree and drug distribution. Furthermore, their antiatherogenic efficacies were elaborately evaluated and compared by typical biochemical indices. With AA modification amount augmenting, circulation time of AA-LT-d-rHDL was prolonged, and drug accumulation in the target locus was increased, eventually the significant appreciation in antiatherogenic efficacies were further supported by lower level of bad cholesterol, decreased atherosclerotic lesions areas and mean intima-media thickness (MIT), markedly attenuated matrix metalloproteinase-9 (MMP-9) protein expression and macrophage infiltration. This proof-of-concept study demonstrated that AA-LT-d-rHDL could enhance drug accumulation in atherosclerotic lesion and impede atherosclerosis progression more effectively.

Ibuprofen-loaded poly(lactic-co-glycolic acid films for controlled drug release

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Pang JM

2011-04-01

Full Text Available Jianmei Pang1, Yuxia Luan1, Feifei Li1, Xiaoqing Cai1, Jimin Du2, Zhonghao Li31School of Pharmaceutical Science, Shandong University, Jinan, Shandong Province, PR China; 2School of Chemistry and Chemical Engineering, Anyang Normal University, Henan Province, PR China; 3School of Materials Science and Engineering, Shandong University, Jinan, Shandong Province, PR ChinaAbstract: Ibuprofen- (IBU loaded biocompatible poly(lactic-co-glycolic acid (PLGA films were prepared by spreading polymer/ibuprofen solution on the nonsolvent surface. By controlling the weight ratio of drug and polymer, different drug loading polymer films can be obtained. The synthesized ibuprofen-loaded PLGA films were characterized with scanning electron microscopy, powder X-ray diffraction, and differential scanning calorimetry. The drug release behavior of the as-prepared IBU-loaded PLGA films was studied to reveal their potential application in drug delivery systems. The results show the feasibility of the as-obtained films for controlling drug release. Furthermore, the drug release rate of the film could be controlled by the drug loading content and the release medium. The development of a biodegradable ibuprofen system, based on films, should be of great interest in drug delivery systems.Keywords: ibuprofen, controlled release, poly(lactic-co-glycolic acid, films

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.

Neutralization method for a hydrofluoric acid release

International Nuclear Information System (INIS)

Williams, D.L.; Deacon, L.E.

1976-01-01

A laboratory investigation of methods for neutralizing a release at the hydrofluoric acid tank farm at the Portsmouth Gaseous Diffusion Plant has revealed that the best neutralization method incorporates the use of a lime/water slurry. In this method, settling of suspended solids in the liquid is enhanced by the application of sodium dodecyl sulfate, which causes immediate flocculation and settling. Dilution and expulsion of the supernatant liquid above the flocculated solids result in an effluent which meets the one part per million fluoride limit established by the U.S. Environmental Protection Agency. A fluoride specific ion electrode is used to determine fluoride concentration. This method presently is being adapted for use in the hydrofluoric acid tank farm and is being considered for use at the plant's fluorine generation facility. It could be adapted for use in any facility that contains fluoride in aqueous solution

Activation and inactivation of the volume-sensitive taurine leak pathway in NIH3T3 fibroblasts and Ehrlich Lettre ascites cells

DEFF Research Database (Denmark)

Lambert, Ian Henry

2007-01-01

Hypotonic exposure provokes the mobilization of arachidonic acid, production of ROS, and a transient increase in taurine release in Ehrlich Lettre cells. The taurine release is potentiated by H(2)O(2) and the tyrosine phosphatase inhibitor vanadate and reduced by the phospholipase A(2) (PLA(2......)) inhibitors bromoenol lactone (BEL) and manoalide, the 5-lipoxygenase (5-LO) inhibitor ETH-615139, the NADPH oxidase inhibitor diphenyl iodonium (DPI), and antioxidants. Thus, swelling-induced taurine efflux in Ehrlich Lettre cells involves Ca(2+)-independent (iPLA(2))/secretory PLA(2) (sPLA(2)) plus 5-LO...... activity and modulation by ROS. Vanadate and H(2)O(2) stimulate arachidonic acid mobilization and vanadate potentiates ROS production in Ehrlich Lettre cells and NIH3T3 fibroblasts under hypotonic conditions. However, vanadate-induced potentiation of the volume-sensitive taurine efflux is, in both cell...

Carboxylic acid functionalization of halloysite nanotubes for sustained release of diphenhydramine hydrochloride

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Zargarian, S. Sh.; Haddadi-Asl, V., E-mail: haddadi@aut.ac.ir; Hematpour, H. [Amirkabir University of Technology, Department of Polymer Engineering and Color Technology (Iran, Islamic Republic of)

2015-05-15

Halloysite nanotubes (HNT) (cylindrical shape with external diameter and length in the range of 30–80 nm and 0.2–1 µm, respectively) were functionalized with 3-aminopropyltriethoxysilane (APTES) from hydroxyl groups by a coupling reaction. Subsequently, maleic anhydride was attached to the APTES moieties to yield carboxylic acid-functionalized HNT. Loading and subsequent release of a model drug molecule diphenhydramine hydrochloride (DPH) on modified and unmodified nanotubes were investigated. Morphology of HNT was studied by electron microscopy. Successful attachment of APTES and carboxylic acid groups to halloysite and drug loading were evaluated by Fourier transform infrared spectroscopy. The amount of surface modification and drug adsorption capacity were calculated via thermogravimetric analysis. The ordered crystal structure of loaded drug was evaluated by X-ray diffraction. UV–Visible spectrophotometer was used to study drug release from modified and unmodified samples. Carboxylated halloysite exhibits higher loading capacity and prolonged release of DPH as compared to that of the natural halloysite.

Carboxylic acid functionalization of halloysite nanotubes for sustained release of diphenhydramine hydrochloride

International Nuclear Information System (INIS)

Zargarian, S. Sh.; Haddadi-Asl, V.; Hematpour, H.

2015-01-01

Halloysite nanotubes (HNT) (cylindrical shape with external diameter and length in the range of 30–80 nm and 0.2–1 µm, respectively) were functionalized with 3-aminopropyltriethoxysilane (APTES) from hydroxyl groups by a coupling reaction. Subsequently, maleic anhydride was attached to the APTES moieties to yield carboxylic acid-functionalized HNT. Loading and subsequent release of a model drug molecule diphenhydramine hydrochloride (DPH) on modified and unmodified nanotubes were investigated. Morphology of HNT was studied by electron microscopy. Successful attachment of APTES and carboxylic acid groups to halloysite and drug loading were evaluated by Fourier transform infrared spectroscopy. The amount of surface modification and drug adsorption capacity were calculated via thermogravimetric analysis. The ordered crystal structure of loaded drug was evaluated by X-ray diffraction. UV–Visible spectrophotometer was used to study drug release from modified and unmodified samples. Carboxylated halloysite exhibits higher loading capacity and prolonged release of DPH as compared to that of the natural halloysite

A study of marine pollution caused by the release of metals into seawater following acid spills.

Science.gov (United States)

Cabon, Jean-Yves; Giamarchi, Philippe; Le Floch, Stephane

2010-07-01

This study examined the potential metal pollution induced by the accidental spill of different acids into seawater. The acids sink to the bottom according to their densities and subsequently react with marine sediments. The acids selected for this study were acetic, hydrochloric, nitric, sulfuric, and phosphoric acids; the metallic elements selected were Cr, Cu, Fe, Mn, Pb and Zn. The sediment was collected in Brest Harbour. The percentages of metals released from this sediment in the presence of various concentrations of acids in seawater were important; concentrations of approximately 7 mg L(-1) for Mn and 60 mg L(-1) for Zn were observed under our experimental conditions. We also examined the rate of release of these metals from the sediment into the seawater in the presence of the different acids and under different experimental conditions. We found that most of the metallic elements were released from the sediments into the seawater during the first fifteen minutes of exposure. After this time, a high degree of pollution was induced if acids leached into seawater were not rapidly diluted. Copyright 2010 Elsevier Ltd. All rights reserved.

Proximate composition, amino acid and fatty acid composition of fish maws.

Science.gov (United States)

Wen, Jing; Zeng, Ling; Xu, Youhou; Sun, Yulin; Chen, Ziming; Fan, Sigang

2016-01-01

Fish maws are commonly recommended and consumed in Asia over many centuries because it is believed to have some traditional medical properties. This study highlights and provides new information on the proximate composition, amino acid and fatty acid composition of fish maws of Cynoscion acoupa, Congresox talabonoides and Sciades proops. The results indicated that fish maws were excellent protein sources and low in fat content. The proteins in fish maws were rich in functional amino acids (FAAs) and the ratio of FAAs and total amino acids in fish maws ranged from 0.68 to 0.69. Among species, croaker C. acoupa contained the most polyunsaturated fatty acids, arachidonic acid, docosahexaenoic acid and eicosapntemacnioc acid, showing the lowest value of index of atherogenicity and index of thrombogenicity, showing the highest value of hypocholesterolemic/hypercholesterolemic ratio, which is the most desirable.

Release of Polyphenols Is the Major Factor Influencing the Bioconversion of Rice Straw to Lactic Acid.

Science.gov (United States)

Chen, Xingxuan; Xue, Yiyun; Hu, Jiajun; Tsang, Yiu Fai; Gao, Min-Tian

2017-11-01

In this study, we found that p-coumaric acid (p-CA), ferulic acid (FA), and condensed tannins were released from rice straw during saccharification. The presence of polyphenols prolonged the lag phase and lowered the productivity of lactic acid. p-CA was identified as a key inhibitor. Tannins had a lower inhibitory effect than p-CA; FA had little inhibitory effect. Acid, alkaline, and ball milling pretreatments elicited different levels of polyphenol release from rice straw. Due to the different levels of polyphenol release in the pretreatment step, the enzymatic hydrolysates contained different concentrations of polyphenols. Compared with fermentation with a synthetic medium, fermentation with the hydrolysates of ball-milled rice straw provided much lower productivity and yield of lactic acid due to the presence of polyphenols. Removal of these compounds played an important role in lactic acid fermentation. When rice straw was alkaline pretreated, the hydrolysates contained few phenolic compounds, resulting in high productivity and yield of lactic acid (1.8 g/L/h and 26.7 g/100 g straw), which were comparable to those in a synthetic medium. This indicates that there is a correlation between removal of phenolic compounds and efficiency in lactic acid fermentation.

An investigation into the mechanisms of drug release from taste-masking fatty acid microspheres.

Science.gov (United States)

Qi, Sheng; Deutsch, David; Craig, Duncan Q M

2008-09-01

Fatty acid microspheres based on stearic and palmitic acids are known to form effective taste masking systems, although the mechanisms by which the drug is preferentially released in the lower gastrointestinal tract are not known. The objective of the present study was to identify the mechanisms involved, with a particular view to clarify the role of acid soap formation in the dissolution process. Microspheres were prepared by a spray chilling process. Using benzoic acid as a model drug and an alkaline dissolution medium, a faster drug release was observed in the mixed fatty acid formulation (50:50 stearic:palmitic acid (w/w)) compared to the single fatty acid component systems. Thermal and powder X-ray diffraction studies indicated a greater degree of acid soap formation for the mixed formulation in alkaline media compared to the single fatty acid systems. Particle size and porosity studies indicated a modest reduction in size for the mixed systems and an increase in porosity on immersion in the dissolution medium. It is proposed that the mixed fatty acid system form a mixed crystal system which in turn facilitates interaction with the dissolution medium, thereby leading to a greater propensity for acid soap formation which in turn forms a permeable liquid crystalline phase through which the drug may diffuse. The role of dissolution of palmitic acid into the dissolution medium is also discussed as a secondary mechanism.

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...... and docosahexaenoic acid (22:6 n-3) (DHA) had accumulated in ovarian polar lipids......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...... (EFA) resembling wild European eel were sampled after 0, 5, 10, 14 and 44 weeks of feeding to examine changes in fatty acid composition (FAC) in ovaries, visceral fat and muscle. The results showed a slow but steady incorporation of EFA. Lipids are incorporated in the oocytes early in oogenesis...

Measurement of 12(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid and its metabolite 12-oxo-5Z,8E,10E-heptadecatrienoic acid in human plasma by gas chromatography/negative ion chemical ionization mass spectrometry

International Nuclear Information System (INIS)

Hofmann, U.; Seefried, S.; Meese, C.O.; Mettang, T.; Huebel, E.K.; Kuhlmann, U.

1990-01-01

Thromboxane A2, the predominant product of arachidonic acid metabolism in the blood platelet, is a potent vasoconstrictor and platelet agonist. During its biosynthesis from cyclic endoperoxide, 12(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid (HHT) is formed in equal amounts. The further metabolism of HHT, catalyzed by 15-hydroxyprostaglandin dehydrogenase, leads to 12-oxo-5Z,8E,10E-heptadecatrienoic acid (Oxo-HT). Sample workup procedures are described which allow for the sensitive and reproducible determination of these two arachidonic acid metabolites in human plasma by gas chromatography-mass spectrometry in the presence of deuterated analogues as internal standards. HHT is derivatized to the pentafluorobenzyl ester tert-butyldimethylsilyl ether. In order to enable quantification of low concentrations of about 10 pg/ml in nonstimulated human plasma, the samples have to be purified by HPLC. Oxo-HT is derivatized to the pentafluorobenzyl ester, which is purified by HPLC, and then derivatized to the trimethylsilyloxime. The method allows quantification of Oxo-HT in concentrations down to 10 pg/ml plasma. The reported methods have been used to measure HHT and Oxo-HT in stimulated platelet rich plasma and to quantify HHT in nonstimulated plasma. Determination of endogenous levels of these two arachidonic acid metabolites may give new insights into the overall biosynthesis of thromboxane A2 in man

Cross-Linked Dependency of Boronic Acid-Conjugated Chitosan Nanoparticles by Diols for Sustained Insulin Release

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Nabil A. Siddiqui

2016-10-01

Full Text Available Boronic acids have been widely investigated for their potential use as glucose sensors in glucose responsive polymeric insulin delivery systems. Interactions between cyclic diols and boronic acids, anchored to polymeric delivery systems, may result in swelling of the delivery system, releasing the drug. In this study, 4-formylphenylboronic acid conjugated chitosan was formulated into insulin containing nanoparticles via polyelectrolyte complexation. The nanoparticles had an average diameter of 140 ± 12.8 nm, polydispersity index of 0.17 ± 0.1, zeta potential of +19.1 ± 0.69 mV, encapsulation efficiency of 81% ± 1.2%, and an insulin loading capacity of 46% ± 1.8% w/w. Changes in size of the nanoparticles and release of insulin were type of sugar- and concentration-dependent. High concentration of diols resulted in a sustained release of insulin due to crosslink formation with boronic acid moieties within the nanoparticles. The formulation has potential to be developed into a self-regulated insulin delivery system for the treatment of diabetes.

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

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Francesco Gatto

2016-07-01

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

Omega-3 fatty acids for breast cancer prevention and survivorship.

Science.gov (United States)

Fabian, Carol J; Kimler, Bruce F; Hursting, Stephen D

2015-05-04

Women with evidence of high intake ratios of the marine omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) relative to the omega-6 arachidonic acid have been found to have a reduced risk of breast cancer compared with those with low ratios in some but not all case-control and cohort studies. If increasing EPA and DHA relative to arachidonic acid is effective in reducing breast cancer risk, likely mechanisms include reduction in proinflammatory lipid derivatives, inhibition of nuclear factor-κB-induced cytokine production, and decreased growth factor receptor signaling as a result of alteration in membrane lipid rafts. Primary prevention trials with either risk biomarkers or cancer incidence as endpoints are underway but final results of these trials are currently unavailable. EPA and DHA supplementation is also being explored in an effort to help prevent or alleviate common problems after a breast cancer diagnosis, including cardiac and cognitive dysfunction and chemotherapy-induced peripheral neuropathy. The insulin-sensitizing and anabolic properties of EPA and DHA also suggest supplementation studies to determine whether these omega-3 fatty acids might reduce chemotherapy-associated loss of muscle mass and weight gain. We will briefly review relevant omega-3 fatty acid metabolism, and early investigations in breast cancer prevention and survivorship.

Electron autoradiographic study of intracellular conversion of fatty acids into glycogen in rats with alloxan diabetes

International Nuclear Information System (INIS)

Lebkova, N.P.; Bobkov, Y.I.; Gorbonova, V.D.; Kolesova, O.E.

1985-01-01

An electron-autoradiographic study was undertaken of the intracellular distribution of hydrogen of fatty acids in alloxan diabetes. Alloxan diabetes was induced in rats; between 2 weeks and 2 months after development of the disease 0.1 ml of tritium-oleic or tritium-arachidonic acid was injected into the caudel vein of the rats. After decapitation, myocardial tissue from the subendocardial zone of the left ventricle, liver tissue, and glycogen isolated from the liver by a biochemical method, were taken for electron-autoradiographic investigation. Analysis of the data showed that a radioactive isotope, injected into the blood stream of the animals in the form of oleic or arachidonic acids, is incorporated into various structures of hepatocytes and cardiomyocytes. Direct proof is obtained to show that glycogen in hepatocytes and cardiomyoctyes of diabetic rats may be formed from fatty acids

Melatonin prevents maternal fructose intake-induced programmed hypertension in the offspring: roles of nitric oxide and arachidonic acid metabolites.

Science.gov (United States)

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

2014-08-01

Fructose intake has increased globally and is linked to hypertension. Melatonin was reported to prevent hypertension development. In this study, we examined whether maternal high fructose (HF) intake causes programmed hypertension and whether melatonin therapy confers protection against the process, with a focus on the link to epigenetic changes in the kidney using next-generation RNA sequencing (NGS) technology. Pregnant Sprague-Dawley rats received regular chow or chow supplemented with HF (60% diet by weight) alone or with additional 0.01% melatonin in drinking water during the whole period of pregnancy and lactation. Male offspring were assigned to four groups: control, HF, control + melatonin (M), and HF + M. Maternal HF caused increases in blood pressure (BP) in the 12-wk-old offspring. Melatonin therapy blunted the HF-induced programmed hypertension and increased nitric oxide (NO) level in the kidney. The identified differential expressed gene (DEGs) that are related to regulation of BP included Ephx2, Col1a2, Gucy1a3, Npr3, Aqp2, Hba-a2, and Ptgs1. Of which, melatonin therapy inhibited expression and activity of soluble epoxide hydrolase (SEH, Ephx2 gene encoding protein). In addition, we found genes in arachidonic acid metabolism were potentially involved in the HF-induced programmed hypertension and were affected by melatonin therapy. Together, our data suggest that the beneficial effects of melatonin are attributed to its ability to increase NO level in the kidney, epigenetic regulation of genes related to BP control, and inhibition of SEH expression. The roles of DEGs by the NGS in long-term epigenetic changes in the adult offspring kidney require further clarification. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Development of Poly Lactic/Glycolic Acid (PLGA Microspheres for Controlled Release of Rho-Associated Kinase Inhibitor

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Sho Koda

2017-01-01

Full Text Available Purpose. The purpose of this study was to investigate the feasibility of poly lactic/glycolic acid (PLGA as a drug delivery carrier of Rho kinase (ROCK inhibitor for the treatment of corneal endothelial disease. Method. ROCK inhibitor Y-27632 and PLGA were dissolved in water with or without gelatin (W1, and a double emulsion [(W1/O/W2] was formed with dichloromethane (O and polyvinyl alcohol (W2. Drug release curve was obtained by evaluating the released Y-27632 by using high performance liquid chromatography. PLGA was injected into the anterior chamber or subconjunctiva in rabbit eyes, and ocular complication was evaluated by slitlamp microscope and histological analysis. Results. Y-27632 incorporated PLGA microspheres with different molecular weights, and different composition ratios of lactic acid and glycolic acid were fabricated. A high molecular weight and low content of glycolic acid produced a slower and longer release. The Y-27632 released from PLGA microspheres significantly promoted the cell proliferation of cultured corneal endothelial cells. The injection of PLGA did not induce any evident eye complication. Conclusions. ROCK inhibitor-incorporated PLGA microspheres were fabricated, and the microspheres achieved the sustained release of ROCK inhibitor over 7–10 days in vitro. Our data should encourage researchers to use PLGA microspheres for treating corneal endothelial diseases.

In situ microdialysis of intramuscular prostaglandin and thromboxane in contracting skeletal muscle in humans

DEFF Research Database (Denmark)

Karamouzis, M; Langberg, Henning; Skovgaard, D

2001-01-01

Arachidonic acid metabolites, especially prostacyclin I2, are regulators of vascular tone, and may be released from contracting muscle. In the present study, the influence of exercise on accumulation of prostaglandins and thromboxane in skeletal muscle was determined by the use of microdialysis...

Enantioselective changes in oxidative stress and toxin release in Microcystis aeruginosa exposed to chiral herbicide diclofop acid

Energy Technology Data Exchange (ETDEWEB)

Ye, Jing [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418 (China); MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Natural Research and Environmental Sciences, Zhejiang University, Hangzhou 310058 (China); Zhang, Ying [Department of Environmental Science, East China Normal University, Shanghai 200241 (China); Chen, Shengwen [School of Urban Development and Environment Engineering, Shanghai Second Polytechnic University, Shanghai 201209 (China); Liu, Chaonan; Zhu, Yongqiang [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418 (China); Liu, Weiping, E-mail: wliu@zju.edu.cn [MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Natural Research and Environmental Sciences, Zhejiang University, Hangzhou 310058 (China)

2014-01-15

Highlights: •The first study on enantioselective oxidative stress and toxin release from Microcystis aeruginosa. •Provide information for the R-enantiomer poses more oxidative stress than the S-enantiomer. •Lifecycle analysis of chiral pollutants needs more attention in environmental assessment. -- Abstract: Enantioselective oxidative stress and toxin release from Microcystis aeruginosa after exposure to the chiral herbicide diclofop acid were investigated. Racemic diclofop acid, R-diclofop acid and S-diclofop acid induced reactive oxygen species (ROS) generation, increased the concentration of malondialdehyde (MDA), enhanced the activity of superoxide dismutase (SOD) and triggered toxin release in M. aeruginosa to varying degrees. The increase in MDA concentration and SOD activity in M. aeruginosa occurred sooner after exposure to diclofop acid than when the cyanobacteria was exposed to either the R- and the S-enantiomer. In addition, enantioselective toxicity of the enantiomers was observed. The R-enantiomer trigged more ROS generation, more SOD activity and more toxin synthesis and release in M. aeruginosa cells than the S-enantiomer. Diclofop acid and its R-enantiomer may collapse the transmembrane proton gradient and destroy the cell membrane through lipid peroxidation and free radical oxidation, whereas the S-enantiomer did not demonstrate such action. R-diclofop acid inhibits the growth of M. aeruginosa in the early stage, but ultimately induced greater toxin release, which has a deleterious effect on the water column. These results indicate that more comprehensive study is needed to determine the environmental safety of the enantiomers, and application of chiral pesticides requires more direct supervision and training. Additionally, lifecycle analysis of chiral pollutants in aquatic system needs more attention to aide in the environmental assessment of chiral pesticides.

Acid stimulation (sour taste elicits GABA and serotonin release from mouse taste cells.

Directory of Open Access Journals (Sweden)

Yijen A Huang

Full Text Available Several transmitter candidates including serotonin (5-HT, ATP, and norepinephrine (NE have been identified in taste buds. Recently, γ-aminobutyric acid (GABA as well as the associated synthetic enzymes and receptors have also been identified in taste cells. GABA reduces taste-evoked ATP secretion from Receptor cells and is considered to be an inhibitory transmitter in taste buds. However, to date, the identity of GABAergic taste cells and the specific stimulus for GABA release are not well understood. In the present study, we used genetically-engineered Chinese hamster ovary (CHO cells stably co-expressing GABA(B receptors and Gαqo5 proteins to measure GABA release from isolated taste buds. We recorded robust responses from GABA biosensors when they were positioned against taste buds isolated from mouse circumvallate papillae and the buds were depolarized with KCl or a stimulated with an acid (sour taste. In contrast, a mixture of sweet and bitter taste stimuli did not trigger GABA release. KCl- or acid-evoked GABA secretion from taste buds was Ca(2+-dependent; removing Ca(2+ from the bathing medium eliminated GABA secretion. Finally, we isolated individual taste cells to identify the origin of GABA secretion. GABA was released only from Presynaptic (Type III cells and not from Receptor (Type II cells. Previously, we reported that 5-HT released from Presynaptic cells inhibits taste-evoked ATP secretion. Combined with the recent findings that GABA depresses taste-evoked ATP secretion, the present results indicate that GABA and 5-HT are inhibitory transmitters in mouse taste buds and both likely play an important role in modulating taste responses.

Bile Acids Trigger GLP-1 Release Predominantly by Accessing Basolaterally Located G Protein-Coupled Bile Acid Receptors

DEFF Research Database (Denmark)

Brighton, Cheryl A.; Rievaj, Juraj; Kuhre, Rune E.

2015-01-01

Bile acids are well-recognized stimuli of glucagon-like peptide-1 (GLP-1) secretion. This action has been attributed to activation of the G protein-coupled bile acid receptor GPBAR1 (TGR5), although other potential bile acid sensors include the nuclear farnesoid receptor and the apical sodium......-coupled bile acid transporter ASBT. The aim of this study was to identify pathways important for GLP-1 release and to determine whether bile acids target their receptors on GLP-1-secreting L-cells from the apical or basolateral compartment. Using transgenic mice expressing fluorescent sensors specifically in L...... to either TLCA or TDCA. We conclude that the action of bile acids on GLP-1 secretion is predominantly mediated by GPBAR1 located on the basolateral L-cell membrane, suggesting that stimulation of gut hormone secretion may include postabsorptive mechanisms....

Immunoregulation of antitumor response; differential secretion of arachidonic acid metabolites by macrophages during stimulation ''in vitro'' with BCG and ''Corynebacterium parvum''

International Nuclear Information System (INIS)

Tomecki, Jaroslaw; Sukiennik, Jadwiga; Kordowiak, Anna

1993-01-01

The level of arachidonic acid (AA) metabolites in the supernatants of cultures peritoneal exudate cells (PEC) were studied under various conditions using BCG and ''Corynebacterium parvum'' as stimulators. The metabolite levels were analyzed by thin layer chromatography (TLC). The degree of macrophage cytotoxic/cytostatic activity was dependent on the dose and character of stimulators used and the source of macrophages. The application of micro cytotoxicity assay for the evaluation of tumor cell lysis (lung sarcoma SaL-1) ''in vitro'' revealed that peritoneal macrophages from healthy and tumor bearing BALB/c mice may affect the degree of antitumor response. In the supernatants of cultured PEC from tumor bearing mice AA level increased (by 10-fold) in comparison with PEC from healthy mice. Stimulation with BCG induced over a double level of AA in PEC isolated from tumor bearing mice non-stimulated or stimulated with ''C.parvum''. A lower level of prostaglandins (PGs) was found in the supernatants of cultured PEC isolated from healthy mice (stimulated and non-stimulated), but the highest level of PGs was observed in the supernatants of cultured PEC isolated from tumor bearing mice stimulated with BCG. The unique metabolite of AA was found only in the supernatants form non-stimulated PEC from tumor bearing mice. PEC from tumor bearing mice produced metabolites of AA which were not detected in control group. These results suggest that macrophages also play a regulatory role by secretion of AA. This process can be modified by bacterial antigens. (author). 21 refs, 7 figs

Evidence for the essentiality of arachidonic and docosahexaenoic acid in the postnatal maternal and infant diet for the development of the infant's immune system early in life.

Science.gov (United States)

Richard, Caroline; Lewis, Erin D; Field, Catherine J

2016-05-01

Long-chain polyunsaturated fatty acids (LCPUFA), especially the balance between arachidonic (AA) and docosahexaenoic (DHA) acids are known to have important immunomodulatory roles during the postnatal period when the immune system is rapidly developing. AA and DHA are required in infant formula in many countries but are optional in North America. The rationale for adding these LCPUFA to full-term formula is based on their presence in breast milk and randomized controlled studies that suggest improved cognitive function in preterm infants, but results are more variable in full-term infants. Recently, the European Food Safety Authority has proposed, based on a lack of functional evidence, that AA is not required in infant formula for full-term infants during the first year of life but DHA should remain mandatory. The purpose of this review is to review the evidence from epidemiological and intervention studies regarding the essentiality of AA and DHA in the postnatal infant and maternal diet (breast-feeding) for the immune system development early in life. Although studies support the essentiality of DHA for the immune system development, more research is needed to rule out the essentiality of AA. Nevertheless, intervention studies have demonstrated improvement in many markers of immune function in infants fed formula supplemented with AA and DHA compared with unsupplemented formula, which appears to consistently result in beneficial health outcomes including reduction in the risk of developing allergic and atopic disease early in life.

Effects of low molecular weight organic acids on 137Cs release from contaminated soils

International Nuclear Information System (INIS)

Chiang, Po Neng; Wang, Ming Kuang; Huang, Pan Ming; Wang, Jeng Jong

2011-01-01

Radio pollutant removal is one of several priority restoration strategies for the environment. This study assessed the effect of low molecular weight organic acid on the lability and mechanisms for release of 137 Cs from contaminated soils. The amount of 137 Cs radioactivity released from contaminated soils reacting with 0.02 M low molecular weight organic acids (LMWOAs) specifically acetic, succinic, oxalic, tartaric, and citric acid over 48 h were 265, 370, 760, 850, and 1002 Bq kg -1 , respectively. The kinetic results indicate that 137 Cs exhibits a two-step parabolic diffusion equation and a good linear relationship, indicating that the parabolic diffusion equation describes the data quite well, as shown by low p and high r 2 values. The fast stage, which was found to occur within a short period of time (0.083-3 h), corresponds to the interaction of LMWOAs with the surface of clay minerals; meanwhile, during the slow stage, which occurs over a much longer time period (3-24 h), desorption primarily is attributed to inter-particle or intra-particle diffusion. After a fifth renewal of the LMWOAs, the total levels of 137 Cs radioactivity released by acetic, succinic, oxalic, tartaric, and citric acid were equivalent to 390, 520, 3949, 2061, and 4422 Bq kg -1 soil, respectively. H + can protonate the hydroxyl groups and oxygen atoms at the broken edges or surfaces of the minerals, thereby weakening Fe-O and Al-O bonds. After protonation of H + , organic ligands can attack the OH and OH 2 groups in the minerals easily, to form complexes with surface structure cations, such as Al and Fe. The amounts of 137 Cs released from contaminated soil treated with LMWOAs were substantially increased, indicating that the LMWOAs excreted by the roots of plants play a critical role in 137 Cs release.

Tissue levels of fish fatty acids and risk of colorectal adenomas: a case-control study (Netherlands).

NARCIS (Netherlands)

Busstra, M.C.; Siezen, C.L.; Grubben, M.J.A.L.; Kranen, H.J. van; Nagengast, F.M.; Veer, P. van 't

2003-01-01

Epidemiological and animal studies have suggested that a high ratio of n-3 fish fatty acids to arachidonic acid (AA), might protect against colorectal carcinogenesis. Competition of n-3 and n-6 fatty acids, especially AA, for the enzyme cyclooxygenase-2 may be responsible for this effect. To examine

Tissue levels of fish fatty acids and risk of colorectal adenomas: a case-control study (Netherlands)

NARCIS (Netherlands)

Busstra, M.C.; Siezen, C.L.E.; Grubben, M.J.A.L.; Kranen, H.J.; Nagengast, F.M.; Veer, van 't P.

2003-01-01

Epidemiological and animal studies have suggested that a high ratio of n-3 fish fatty acids to arachidonic acid (AA), might protect against colorectal carcinogenesis. Competition of n-3 and n-6 fatty acids, especially AA, for the enzyme cyclooxygenase-2 may be responsible for this effect. To examine

Effects of global change factors on fatty acids and mycosporine-like amino acid production in Chroothece richteriana (Rhodophyta).

Science.gov (United States)

Gonzalez-Silvera, Daniel; Pérez, Sandra; Korbee, Nathalie; Figueroa, Félix L; Asencio, Antonia D; Aboal, Marina; López-Jiménez, José Ángel

2017-10-01

Under natural conditions, Chroothece richteriana synthesizes a fairly high proportion of fatty acids. However, nothing is known about how environmental changes affect their production, or about the production of protective compounds, when colonies develop under full sunshine with high levels of UV radiation. In this study, wild colonies of C. richteriana were subjected to increasing temperature, conductivity, ammonium concentrations and photosynthetically active radiation (PAR), and UV radiations to assess the potential changes in lipid composition and mycosporine-like amino acids (MAAs) concentration. The PERMANOVA analysis detected no differences for the whole fatty acid profile among treatments, but the percentages of α-linolenic acid and total polyunsaturated fatty acids increased at the lowest assayed temperature. The percentages of linoleic and α-linolenic acids increased with lowering temperature. γ-linolenic and arachidonic acids decreased with increasing conductivity, and a high arachidonic acid concentration was related with increased conductivity. The samples exposed to UVB radiation showed higher percentages of eicosapentaenoic acid and total monounsaturated fatty acids, at the expense of saturated fatty acids. MAAs accumulation increased but not significantly at the lowest conductivity, and also with the highest PAR and UVR exposure, while ammonium and temperature had no effect. The observed changes are probably related with adaptations of both membrane fluidity to low temperature, and metabolism to protect cells against UV radiation damage. The results suggest the potential to change lipid composition and MAAs concentration in response to environmental stressful conditions due to climate change, and highlight the interest of the species in future research about the biotechnological production of both compound types. © 2017 Phycological Society of America.

Adsorption and release of amino acids mixture onto apatitic calcium phosphates analogous to bone mineral

Science.gov (United States)

El Rhilassi, A.; Mourabet, M.; El Boujaady, H.; Bennani-Ziatni, M.; Hamri, R. El; Taitai, A.

2012-10-01

Study focused on the interaction of adsorbate with poorly crystalline apatitic calcium phosphates analogous to bone mineral. Calcium phosphates prepared in water-ethanol medium at physiological temperature (37 °C) and neutral pH, their Ca/P ratio was between 1.33 and 1.67. Adsorbate used in this paper takes the mixture form of two essential amino acids L-lysine and DL-leucine which have respectively a character hydrophilic and hydrophobic. Adsorption and release are investigated experimentally; they are dependent on the phosphate type and on the nature of adsorbate L-lysine, DL-leucine and their mixture. Adsorption of mixture of amino acids on the apatitic calcium phosphates is influenced by the competition between the two amino acids: L-lysine and DL-leucine which exist in the medium reaction. The adsorption kinetics is very fast while the release kinetics is slow. The chemical composition of apatite has an influence on both adsorption and release. The interactions adsorbate-adsorbent are electrostatic type. Adsorption and release reactions of the amino acid mixture are explained by the existence of the hydrated surface layer of calcium phosphate apatite. The charged sbnd COOsbnd and sbnd NH3+ of adsorbates are the strongest groups that interact with the surface of apatites, the adsorption is mainly due to the electrostatic interaction between the groups sbnd COOsbnd of amino acids and calcium Ca2+ ions of the apatite. Comparative study of interactions between adsorbates (L-lysine, DL-leucine and their mixture) and apatitic calcium phosphates is carried out in vitro by using UV-vis and infrared spectroscopy IR techniques.

Improving release completeness from PLGA-based implants for the acid-labile model protein ovalbumin.

Science.gov (United States)

Duque, Luisa; Körber, Martin; Bodmeier, Roland

2018-03-01

The objectives of this study were to assess the feasibility of hot melt extrusion (HME) for the preparation of PLGA-based ovalbumin-loaded implants as well as to characterize and improve protein release from the implants. Ovalbumin (OVA) was stable during extrusion, which was attributed to a protective effect of the biodegradable matrix. OVA release was characterized by a low burst, a slow release up to day 21, which plateaued thereafter resulting in incomplete release for all evaluated protein loadings. Release incompleteness was accompanied by the formation of an insoluble residual mass. Further characterization of this mass indicated that it consisted of non-covalent protein aggregates and polymer, where ovalbumin was ionically bound as the pH inside the degrading matrix decreased below the pI of the protein. Although higher protein release was obtained with the inclusion of weak bases because of their neutralizing effect, OVA aggregation and release incompleteness were not fully avoided. With the use of shellac, a well-known enteric and biocompatible polymer, as protective excipient, a distinct late release phase occurred and release completeness was increased to more than 75% cumulative release. Shellac apparently protected the protein against the acidic microclimate due to its low solubility at low pH. Protected OVA was thus released once the pH increased due to a declining PLGA-oligomer formation. The result was a triphasic release profile consisting of an initial burst, a slow diffusion phase over about 7 weeks, and an erosion-controlled dissolution phase over the next 3 weeks. An acid-labile protein like OVA was thus feasibly protected from interactions with PLGA and its degradation products, resulting in a controlled delivery of more than 85% of the original payload. Copyright © 2018 Elsevier B.V. All rights reserved.

Cathepsin B-sensitive polymers for compartment-specific degradation and nucleic acid release.

Science.gov (United States)

Chu, David S H; Johnson, Russell N; Pun, Suzie H

2012-02-10

Degradable cationic polymers are desirable for in vivo nucleic acid delivery because they offer significantly decreased toxicity over non-degradable counterparts. Peptide linkers provide chemical stability and high specificity for particular endopeptidases but have not been extensively studied for nucleic acid delivery applications. In this work, enzymatically degradable peptide-HPMA copolymers were synthesized by RAFT polymerization of HPMA with methacrylamido-terminated peptide macromonomers, resulting in polymers with low polydispersity and near quantitative incorporation of peptides. Three peptide-HPMA copolymers were evaluated: (i) pHCathK(10), containing peptides composed of the linker phe-lys-phe-leu (FKFL), a substrate of the endosomal/lysosomal endopeptidase cathepsin B, connected to oligo-(L)-lysine for nucleic acid binding, (ii) pHCath(D)K(10), containing the FKFL linker with oligo-(D)-lysine, and (iii) pH(D)Cath(D)K(10), containing all (D) amino acids. Cathepsin B degraded copolymers pHCathK(10) and pHCath(D)K(10) within 1 h while no degradation of pH(D)Cath(D)K(10) was observed. Polyplexes formed with pHCathK(10) copolymers show DNA release by 4 h of treatment with cathepsin B; comparatively, polyplexes formed with pHCath(D)K(10) and pH(D)Cath(D)K(10) show no DNA release within 8 h. Transfection efficiency in HeLa and NIH/3T3 cells were comparable between the copolymers but pHCathK(10) was less toxic. This work demonstrates the successful application of peptide linkers for degradable cationic polymers and DNA release. Copyright © 2011 Elsevier B.V. All rights reserved.

Biosíntesis de los productos del ácido araquidónico y su repercusión sobre la inflamación

Directory of Open Access Journals (Sweden)

Andrés O Pérez Ruiz

1998-08-01

Full Text Available La liberación de ácido araquidónico o de otros ácidos grasos insaturados de 20 átomos de carbono, el icosatrienoico y el ecosapentanoico, de las reservas hísticas, es la primera fase de la síntesis de las prostaglandinas, tromboxanos y leucotrienos. Una vez liberado el ácido araquidónico de las reservas hísticas, se inicia su transformación en prostaciclina, prostaglandinas y tromboxano mediante la ciclación e incorporación de oxígeno molecular, catalizada por la ciclooxigenasa que está presente en la mayoría de las células. Las lipooxigenasas metabolizan también el ácido araquidónico hasta dar diversos productos con el grupo hidroxi-peroxi en posiciones distintas e incrementar así la síntesis de leucotrienos. Los metabolitos del ácido araquidónico, tanto de la vía de la ciclooxigenasa como de la lipooxigenasa, tienen una definida e importante participación en las diversas etapas del proceso inflamatorio. Diversos fármacos contribuyen a mejorar el proceso inflamatorio al inhibir enzimas específicas.The release of arachidonic acid or other unsaturated 20-carbon fatty acids, the icosatrienoic and icopentanoic acids, from hystic reserves is the first phase of the prostaglandins, thromboxines and leukotrienes synthesis. Once the arachidonic acid is released from thystic reserves, it is then turned into prostacyclines, prostaglandins and thromboxines through molecular oxygen cycling and addition catalyzed by cyclooxygenase present in the majority of cells. The lipoxygenases also metabolize the arachidonic acid into various products with hidroi-peroxi group in different positions and thus increase the leukotriene biosynthesis. The arachidonic acid metabolites resulted from both cycloxigenase and lipoxygenase action have a defined and important role in the various inflammatory process phases. Several pharmaceuticals assist in improving the inflammatory process by the inhibition of specific enzymes.

Identification and characterization of zebrafish thrombocytes.

Science.gov (United States)

Jagadeeswaran, P; Sheehan, J P; Craig, F E; Troyer, D

1999-12-01

To analyse primary haemostasis in the zebrafish we have identified and characterized the zebrafish thrombocyte by morphologic, immunologic and functional approaches. Novel methods were developed for harvesting zebrafish blood with preservation of thrombocytes, and assaying whole blood adhesion/aggregation responses in microtitre plates. Light and electron microscopy of the thrombocyte illustrated morphological characteristics including the formation of aggregates, pseudopodia, and surface-connected vesicles analagous to the platelet canalicular system. Immunostaining with polyclonal antisera versus human platelet glycoproteins demonstrated the presence of glycoprotein Ib and IIb/IIIa-like complexes on the thrombocyte surface. Whole blood assays for adhesion/aggregation and ATP release showed ristocetin-induced adhesion without ATP release, and platelet agonist (collagen, arachidonic acid) induced aggregation with ATP release. Blood harvested from zebrafish treated with aspirin demonstrated inhibition of arachidonic acid induced aggregation and agonist induced ATP release, consistent with at least partial dependence on an intact cyclo oxygenase pathway. The combined morphologic immunologic and functional evidence suggest that the zebrafish thrombocyte is the haemostatic homologue of the mammalian platelet. Conservation of major haemostatic pathways involved in platelet function and coagulation suggests that the zebrafish is a relevant model for mammalian haemostasis and thrombosis.

Altered aortic and cremaster muscle prostaglandin synthesis in diabetic rats

International Nuclear Information System (INIS)

Myers, T.O.; Messina, E.J.; Rodrigues, A.M.; Gerritsen, M.E.

1985-01-01

Alterations in the synthesis and release of prostaglandins have been reported in humans and animal models of diabetes mellitus. In the present study synthesis and release of prostaglandins by thoracic aorta and cremaster muscle of rats with streptozotocin-induced diabetes of 8 wk duration was compared with age-matched controls. Prostaglandin synthesis was assessed by the measurement of immunoreactive prostaglandin E2 (PGE2) and 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha) release and by quantifying metabolism of exogenous [1- 14 C]arachidonic acid by thoracic aortic rings and minced cremaster muscle. These studies indicate that diminished prostacyclin (PGI2) and/or PGE2 production is not a general feature of all diabetic vascular tissues, suggesting that large and small blood vessels may not be similarly affected by diabetes in regard to the metabolism of exogenous arachidonic acid and the synthesis and release of prostaglandins. Furthermore, the vascular changes often observed in conjunction with diabetes, i.e., alterations in vascular reactivity and microangiopathy in small blood vessels and atherosclerosis of large blood vessels may be related in some way to the segmental differences observed in prostaglandin synthesis

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.

PAR-2 activation enhances weak acid-induced ATP release through TRPV1 and ASIC sensitization in human esophageal epithelial cells.

Science.gov (United States)

Wu, Liping; Oshima, Tadayuki; Shan, Jing; Sei, Hiroo; Tomita, Toshihiko; Ohda, Yoshio; Fukui, Hirokazu; Watari, Jiro; Miwa, Hiroto

2015-10-15

Esophageal visceral hypersensitivity has been proposed to be the pathogenesis of heartburn sensation in nonerosive reflux disease. Protease-activated receptor-2 (PAR-2) is expressed in human esophageal epithelial cells and is believed to play a role in inflammation and sensation. PAR-2 activation may modulate these responses through adenosine triphosphate (ATP) release, which is involved in transduction of sensation and pain. The transient receptor potential vanilloid receptor 1 (TRPV1) and acid-sensing ion channels (ASICs) are both acid-sensitive nociceptors. However, the interaction among these molecules and the mechanisms of heartburn sensation are still not clear. We therefore examined whether ATP release in human esophageal epithelial cells in response to acid is modulated by TRPV1 and ASICs and whether PAR-2 activation influences the sensitivity of TRPV1 and ASICs. Weak acid (pH 5) stimulated the release of ATP from primary human esophageal epithelial cells (HEECs). This effect was significantly reduced after pretreatment with 5-iodoresiniferatoxin (IRTX), a TRPV1-specific antagonist, or with amiloride, a nonselective ASIC blocker. TRPV1 and ASIC3 small interfering RNA (siRNA) transfection also decreased weak acid-induced ATP release. Pretreatment of HEECs with trypsin, tryptase, or a PAR-2 agonist enhanced weak acid-induced ATP release. Trypsin treatment led to the phosphorylation of TRPV1. Acid-induced ATP release enhancement by trypsin was partially blocked by IRTX, amiloride, or a PAR-2 antagonist. Conversely, acid-induced ATP release was augmented by PAR-2 activation through TRPV1 and ASICs. These findings suggested that the pathophysiology of heartburn sensation or esophageal hypersensitivity may be associated with the activation of PAR-2, TRPV1, and ASICs. Copyright © 2015 the American Physiological Society.

Polyunsaturated fatty acids and prostate cancer risk

DEFF Research Database (Denmark)

Khankari, Nikhil K; Murff, Harvey J; Zeng, Chenjie

2016-01-01

BACKGROUND: Prostate cancer is a common cancer worldwide with no established modifiable lifestyle factors to guide prevention. The associations between polyunsaturated fatty acids (PUFAs) and prostate cancer risk have been inconsistent. Using Mendelian randomisation, we evaluated associations...... and prostate cancer risk. However, risk reductions were observed for short-chain PUFAs, linoleic (ORLA=0.95, 95%CI=0.92, 0.98) and α-linolenic acids (ORALA=0.96, 95%CI=0.93, 0.98), among men ...-chain PUFAs (i.e., arachidonic, eicosapentaenoic, and docosapentaenoic acids), increased risks were observed among men

Studies of insulin secretory responses and of arachidonic acid incorporation into phospholipids of stably transfected insulinoma cells that overexpress group VIA phospholipase A2 (iPLA2beta ) indicate a signaling rather than a housekeeping role for iPLA2beta.

Science.gov (United States)

Ma, Z; Ramanadham, S; Wohltmann, M; Bohrer, A; Hsu, F F; Turk, J

2001-04-20

A cytosolic 84-kDa group VIA phospholipase A(2) (iPLA(2)beta) that does not require Ca(2+) for catalysis has been cloned from several sources, including rat and human pancreatic islet beta-cells and murine P388D1 cells. Many potential iPLA(2)beta functions have been proposed, including a signaling role in beta-cell insulin secretion and a role in generating lysophosphatidylcholine acceptors for arachidonic acid incorporation into P388D1 cell phosphatidylcholine (PC). Proposals for iPLA(2)beta function rest in part on effects of inhibiting iPLA(2)beta activity with a bromoenol lactone (BEL) suicide substrate, but BEL also inhibits phosphatidate phosphohydrolase-1 and a group VIB phospholipase A(2). Manipulation of iPLA(2)beta expression by molecular biologic means is an alternative approach to study iPLA(2)beta functions, and we have used a retroviral construct containing iPLA(2)beta cDNA to prepare two INS-1 insulinoma cell clonal lines that stably overexpress iPLA(2)beta. Compared with parental INS-1 cells or cells transfected with empty vector, both iPLA(2)beta-overexpressing lines exhibit amplified insulin secretory responses to glucose and cAMP-elevating agents, and BEL substantially attenuates stimulated secretion. Electrospray ionization mass spectrometric analyses of arachidonic acid incorporation into INS-1 cell PC indicate that neither overexpression nor inhibition of iPLA(2)beta affects the rate or extent of this process in INS-1 cells. Immunocytofluorescence studies with antibodies directed against iPLA(2)beta indicate that cAMP-elevating agents increase perinuclear fluorescence in INS-1 cells, suggesting that iPLA(2)beta associates with nuclei. These studies are more consistent with a signaling than with a housekeeping role for iPLA(2)beta in insulin-secreting beta-cells.

Dual inhibitory action of enadoline (CI977) on release of amino acids in the rat hippocampus.

Science.gov (United States)

Millan, M H; Chapman, A G; Meldrum, B S

1995-06-06

The effect of the kappa-opioid receptor agonist enadoline (CI977, (5R)-(5 alpha,7 alpha,8 beta)-N-methyl-N-[7-(1-pyrrilidinyl)-1-oxaspiro [4,5]dec-8-yl-4-benzofuranacetamide monohydrochloride), on the release of amino acids was studied in the hippocampus of freely moving rats. K+, 100 mM, or veratrine, 100 microM, were applied for 10 min via the dialysis probe, either alone (control groups) or together with CI977 (after a 10 min pretreatment with CI977 in the perfusion medium). To test the specificity of the response to CI977, nor-binaltorphimine, a selective kappa-opioid receptor antagonist, was delivered together with CI977 in two groups of animals. To test the effect of systemic injection, CI977 was given subcutaneously 30 min prior to either stimulus. K(+)-induced release of glutamate and aspartate was significantly reduced by CI977, 2.5 mM; release of gamma-aminobutyric acid (GABA) was reduced by 250 microM CI977 in the probe. The effect of CI977 on release of glutamate and aspartate, but not of GABA, was reversed by nor-binaltorphimine (45 microM). Systemic treatment with CI977, 1 or 10 mg/kg, did not reduce K(+)-induced release of glutamate. Veratrine-induced release of aspartate and glutamate was significantly inhibited by 25 microM and release of GABA by 250 microM CI977 in the probe, and this effect was not modified by nor-binaltorphimine (58 microM). Systemic injection of CI977 1 mg/kg significantly reduced veratrine-induced release of glutamate. These results indicate that CI977 regulates release of amino acids by two independent mechanisms.(ABSTRACT TRUNCATED AT 250 WORDS)

Oleic acid stimulates glucagon-like peptide-1 release from enteroendocrine cells by modulating cell respiration and glycolysis.

Science.gov (United States)

Clara, Rosmarie; Langhans, Wolfgang; Mansouri, Abdelhak

2016-03-01

Glucagon-like peptide-1 (GLP-1) is a potent satiating and incretin hormone released by enteroendocrine L-cells in response to eating. Dietary fat, in particular monounsaturated fatty acids, such as oleic acid (OA), potently stimulates GLP-1 secretion from L-cells. It is, however, unclear whether the intracellular metabolic handling of OA is involved in this effect. First we determined the optimal medium for the bioenergetics measurements. Then we examined the effect of OA on the metabolism of the immortalized enteroendocrine GLUTag cell model and assessed GLP-1 release in parallel. We measured oxygen consumption rate and extracellular acidification rate in response to OA and to different metabolic inhibitors with the Seahorse extracellular flux analyzer. OA increased cellular respiration and potently stimulated GLP-1 release. The fatty acid oxidation inhibitor etomoxir did neither reduce OA-induced respiration nor affect the OA-induced GLP-1 release. In contrast, inhibition of the respiratory chain or of downstream steps of aerobic glycolysis reduced the OA-induced GLP-1 release, and an inhibition of the first step of glycolysis by addition of 2-deoxy-d-glucose even abolished it. These findings indicate that an indirect stimulation of glycolysis is crucial for the OA-induced release of GLP-1. Copyright © 2015 Elsevier Inc. All rights reserved.

Ontogeny of 6-keto-PGF/sub 1α/ synthesis in rabbit aorta and the effect of premature weaning

International Nuclear Information System (INIS)

Bydlowski, S.P.; Yunker, R.L.; Subbiah, M.T.R.

1987-01-01

A systematic study of the ontogeny of aortic 6-ketoprostaglandin F/sub 1α/ synthesis from birth to adult life and the effect of premature weaning on this process was investigated in rabbits. Prostacyclin (PGI 2 ) synthesis by both endogenous and exogenous arachidonic acid and its relation to aortic arachidonic acid content was determined. It was found that 1) PGI 2 synthesis from endogenous arachidonic acid increased with age, whereas 2) PGI 2 synthesis from exogenous arachidonic acid decreased. This correlated with a decrease in the incorporation of [ 14 C]arachidonic acid into phospholipids with age. Aortic arachidonic acid concentration did not change from birth until 3 wk of life but increased markedly by 5 wk of age. Premature weaning caused a decrease in the synthesis of aortic PGI 2 and in aortic arachidonic acid concentration initially, but the changes did not persist in later life. These studies suggest that the utilization of exogenous arachidonic acid by aorta decreases after birth perhaps due to maturity of the enzyme systems that synthesize and utilize endogenous substrates

Swelling and drug release behavior of poly(2-hydroxyethyl methacrylate/itaconic acid) copolymeric hydrogels obtained by gamma irradiation

International Nuclear Information System (INIS)

Tomic, S.Lj.; Micic, M.M.; Filipovic, J.M.; Suljovrujic, E.H.

2007-01-01

The new copolymeric hydrogels based on 2-hydroxyethyl methacrylate (HEMA) and itaconic acid (IA) were prepared by gamma irradiation, in order to examine the potential use of these hydrogels in controlled drug release systems. The influence of IA content in the gel on the swelling characteristics and the releasing behavior of hydrogels, and the effect of different drugs, theophylline (TPH) and fenethylline hydrochloride (FE), on the releasing behavior of P(HEMA/IA) matrix were investigated in vitro. The diffusion exponents for swelling and drug release indicate that the mechanisms of buffer uptake and drug release are governed by Fickian diffusion. The swelling kinetics and, therefore, the release rate depends on the matrix swelling degree. The drug release was faster for copolymeric hydrogels with a higher content of itaconic acid. Furthermore, the drug release for TPH as model drug was faster due to a smaller molecular size and a weaker interaction of the TPH molecules with(in) the P(HEMA/IA) copolymeric networks

Pathway-specific variations in neurovascular and neurometabolic coupling in rat primary somatosensory cortex

DEFF Research Database (Denmark)

Enager, Pia; Hansen, Henning Piilgaard; Offenhauser, Nikolas

2009-01-01

Functional neuroimaging signals are generated, in part, by increases in cerebral blood flow (CBF) evoked by mediators, such as nitric oxide and arachidonic acid derivatives that are released in response to increased neurotransmission. However, it is unknown whether the vascular and metabolic resp...... critically on the type of input, and that a positive blood oxygen level-dependent (BOLD) signal may be a consequence of the activation of both pyramidal cells and inhibitory interneurons.......Functional neuroimaging signals are generated, in part, by increases in cerebral blood flow (CBF) evoked by mediators, such as nitric oxide and arachidonic acid derivatives that are released in response to increased neurotransmission. However, it is unknown whether the vascular and metabolic...... different inputs to a single cortical area. We show that, for a given level of glutamatergic synaptic activity, corticocortical and thalamocortical inputs evoked activity in pyramidal cells and different classes of interneurons, and produced different changes in oxygen consumption and CBF. Furthermore...

Long-wave ultraviolet light induces phospholipase activation in cultured human epidermal keratinocytes

International Nuclear Information System (INIS)

Hanson, D.; DeLeo, V.

1990-01-01

Long wave ultraviolet radiation (UVA) has been shown to play an important role in the overall response of skin to solar radiation, including sunburn, tanning, premature aging, and non-melanoma skin cancer. UVA induction of inflammation in human skin is thought to be mediated by membrane lipid derived products. In order to investigate the mechanism of this response we examined the effect of UVA on phospholipid metabolism of human epidermal keratinocytes in culture. Keratinocytes were grown in serum free low calcium medium. The cells were prelabeled with [3H] arachidonic acid or [3H] choline and irradiated with UVA (Honle 2002-Hg vapor lamp). Identification and quantitation of specific membrane phospholipid-derived components was achieved using high-performance liquid chromatography, paper chromatography, and radioimmunoassay. UVA resulted in a linear dose dependent release of [3H] arachidonic acid into medium between 1 and 20 joule/cm2. This response was inhibited in an oxygen-reduced environment. The radiolabel released was predominantly free arachidonate and cyclooxygenase metabolites. Cyclooxygenase metabolites prostaglandin E2 and prostacyclin derivative, 6-keto-prostaglandin F1a, were stimulated following UVA irradiation, but the lipoxygenase metabolite, leukotriene B was not detected. Maximal release was measured immediately after irradiation and changed little over 24 h post-irradiation. UVA stimulated an increase of [3H] choline metabolites glycerophosphorylcholine and phosphorylcholine in media extracts suggesting UVA activation of phospholipase C and phospholipase A2 or diacylglyceride lipase

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...

Low molecular weight polylactic acid as a matrix for the delayed release of pesticides.

Science.gov (United States)

Zhao, Jing; Wilkins, Richard M

2005-05-18

Low molecular weight polylactic acid (LMW PLA) was used as a matrix to formulate biodegradable matrix granules and films with bromacil using a melt process. The compatibility of the PLA with bromacil was evaluated. The release characteristics of the formulations were investigated in vitro. The degradation and erosion of the formulations were monitored by pH and gravimetric analysis during the course of release. Various granules and films had similar biphasic release patterns, a delayed release followed by an explosive release. The release rates were independent of bromacil content in the matrix, but varied with the geometry of matrices. The mechanisms of diffusion and erosion were involved in the release. The delayed release of the formulations was dominantly governed by the degradation and erosion of PLA. LMW PLA underwent bulk erosion. LMW PLA-based matrix formulations could thus be useful for the application of pesticides to sensitive targets such as seed treatment.

New type of chitosan/2-hydroxypropyl-β-cyclodextrin composite membrane for gallic acid encapsulation and controlled release.

Science.gov (United States)

Paun, Gabriela; Neagu, Elena; Tache, Andreia; Radu, G L

2014-01-01

A new type of chitosan/2-hydroxypropyl-β-cyclodextrin composite membrane have been developed for the encapsulation and controlled release of gallic acid. The morphology of the composite membrane was investigated by infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM), whereas swelling gallic acid and release properties were investigated by UV-visible spectroscopy. The release behavior with pH changes was also explored. The composite membrane based on chitosan/2-hydroxypropyl-β-cyclodextrin with gallic acid included showed improved antioxidant capacities compared to plain chitosan membrane. The information obtained in this study will facilitate the design and preparation of composite membrane based on chitosan and could open a wide range of applications, particularly its use as an antioxidant in food, food packaging, biomedical (biodegradable soft porous scaffolds for enhance the surrounding tissue regeneration), pharmaceutical and cosmetics industries.

Cadmium Alters the Concentration of Fatty Acids in THP-1 Macrophages.

Science.gov (United States)

Olszowski, Tomasz; Gutowska, Izabela; Baranowska-Bosiacka, Irena; Łukomska, Agnieszka; Drozd, Arleta; Chlubek, Dariusz

2018-03-01

Fatty acid composition of human immune cells influences their function. The aim of this study was to evaluate the effects of known toxicant and immunomodulator, cadmium, at low concentrations on levels of selected fatty acids (FAs) in THP-1 macrophages. The differentiation of THP-1 monocytes into macrophages was achieved by administration of phorbol myristate acetate. Macrophages were incubated with various cadmium chloride (CdCl 2 ) solutions for 48 h at final concentrations of 5 nM, 20 nM, 200 nM, and 2 μM CdCl 2 . Fatty acids were extracted from samples according to the Folch method. The fatty acid levels were determined using gas chromatography. The following fatty acids were analyzed: long-chain saturated fatty acids (SFAs) palmitic acid and stearic acid, very long-chain saturated fatty acid (VLSFA) arachidic acid, monounsaturated fatty acids (MUFAs) palmitoleic acid, oleic acid and vaccenic acid, and n-6 polyunsaturated fatty acids (PUFAs) linoleic acid and arachidonic acid. Treatment of macrophages with very low concentrations of cadmium (5-200 nM) resulted in significant reduction in the levels of arachidic, palmitoleic, oleic, vaccenic, and linoleic acids and significant increase in arachidonic acid levels (following exposure to 5 nM Cd), without significant reduction of palmitic and stearic acid levels. Treatment of macrophages with the highest tested cadmium concentration (2 μM) produced significant reduction in the levels of all examined FAs: SFAs, VLSFA, MUFAs, and PUFAs. In conclusion, cadmium at tested concentrations caused significant alterations in THP-1 macrophage fatty acid levels, disrupting their composition, which might dysregulate fatty acid/lipid metabolism thus affecting macrophage behavior and inflammatory state.

[An experimental study on a slow-release complex with rifampicin-polylactic-co-glycolic acid-calcium 
phosphate cement].

Science.gov (United States)

Wu, Jianhuang; Ding, Zhou; Lei, Qing; Li, Miao; Liang, Yan; Lu, Tao

2016-09-28

To prepare the slow-release complex with rifampicin (RFP)-polylactic-co-glycolic acid (PLGA)-calcium phosphate cement (CPC) (RFP-PLGA-CPC complex), and to study its physical and chemical properties and drug release properties in vitro.
 The emulsification-solvent evaporation method was adopted to prepare rifampicin polylactic acid-glycolic acid (RFP-PLGA) slow-release microspheres, which were divided into 3 groups: a calcium phosphate bone cement group (CPC group), a CPC embedded with RFP group (RFP-CPC group), and a PLGA slow-release microspheres carrying RFP and the self-curing CPC group (RFP- PLGA-CPC complex group). The solidification time and porosity of materials were determined. The drug release experiments in vitro were carried out to observe the compressive strength, the change of section morphology before and after drug release. 
 The CPC group showed the shortest solidification time, while the RFP-PLGA-CPC complex group had the longest one. There was statistical difference in the porosity between the CPC group and the RFP-CPC group (Pbehavior of the complex, which was in accordance with zero order kinetics equation F=0.168×t.
 The porosity of RFP-PLGA-CPC complex is significantly higher than that of CPC, and it can keep slow release of the effective anti-tuberculosis drugs and maintain a certain mechanical strength for a long time.

Amino acid and fatty acid compositions of Rusip from fermented Anchovy fish (Stolephorussp)

Science.gov (United States)

Koesoemawardani, D.; Hidayati, S.; Subeki

2018-04-01

Rusip is a typical food of Bangka Belitung Indonesia made from fermented anchovy. This study aims to determine the properties of chemistry, microbiology, composition of amino acids and fatty acids from fermented fish spontaneously and non spontaneously. Spontaneous rusip treatment is done by anchovy fish (Stolephorussp) after cleaning and added salt 25% (w/w) and palm sugar 10% (w/w). While, non-spontaneous rusip is done by adding a culture mixture of Streptococcus, Leuconostoc, and Lactobacillus bacteria 2% (w/v). The materials are then incubated for 2 weeks. The data obtained were then performed t-test at the level of 5%. Spontaneous and non-spontaneous rusip fermentation process showed significant differences in total acid, reducing sugar, salt content, TVN, total lactic acid bacteria, total mold, and total microbial. The dominant amino acid content of spontaneous and non-spontaneous rusip are glutamic acid and aspartic acid, while the dominant fatty acids in spontaneous and non-spontaneous rusip are docosahexaenoic acid, palmitic acid, oleic acid, arachidonic acid, stearic acid, eicosapentaenoic acid, palmitoleic acid, and myristic acid.

Preparation and in vitro evaluation of carboxymethylated κ-carrageenan aluminum hydrogel microbeads for prolonged release of mefenamic acid

International Nuclear Information System (INIS)

Beron, Pia Maria G.; Cruzado, Shervin T.; Dela Cruz, Sharmaine F.; Estanislao, Fides Mae L.; Evangelista, Charina Joy; Mandocdoc, Larra Minnellie W.; Salas, Sharlaine B.; Tiu, Mark Brian C.; Carigma, Andrea Q.; Bayquen, Aristea V.

2012-01-01

Polymers that swell in an aqueous medium have been widely used to formulate controlled-release dosage forms. This study aims to prepare carboxymethyl κ-carrageenan (CMKC) microbeads and evaluate its potential for controlled release of mefenamic acid in comparison to the positive control, carboxymethylcellulose (CMC) microbeads. The powdered κ-carrageenan was carboxymethylated and Fourier-Transform Infrared Spectroscopy confirmed the carboxy methylation. Aqueous solutions of CMC (3% w/v) and CMKC (3%, 4%, 5% w/v) were prepared as microbeads using ionotropic gelation technique. Microbeads were loaded with mefenamic acid by suspending it in the aqueous solution (0.5% w/v) of the drug for 72 hours. Particle size and surface morphology were characterized using scanning electron microscopy. One-way ANOVA was used to determine a significant difference between the release activity of the drug-loaded CMKC and CMC microbeads. Differential Scanning Calorimetry was performed on the drug, drug- free, and drug-loaded microbeads of CMC and CMKC. Two-way ANOVARM showed significant interaction in % drug release of the three groups being analyzed in respect to time effect (p≤0.001) and group effect (p≤0.001). Post Hoc Duncan Multiple Range Test showed that 3% CMC and 4% CMKC has equal average % drug release values and is significantly higher compared to the commercial mefenamic acid. Also, one way ANOVA showed that 3% CMC was able to release the drug with no significant difference in time (p = 0.159), while 4% CMKC (p < 0.001) and the commercial mefenamic acid (p≤0.001) were able to release the drug with significant difference in time (author)

Prostaglandin E2 and thromboxane B2 release from human monocytes treated with bacterial lipopolysaccharide

International Nuclear Information System (INIS)

Nichols, F.C.; Garrison, S.W.; Davis, H.W.

1988-01-01

We investigated the capacity of counterflow-isolated human monocytes to independently synthesize thromboxane B2 (TxB2) and prostaglandin E2 (PGE2) when stimulated with bacterial lipopolysaccharide (LPS). Independent metabolism was confirmed by establishing different specific activities (dpm/ng) of TxB2 and PGE2 released from LPS-treated cells. For metabolites released during the initial 2-hr treatment period, the specific activity of PGE2 was approximately threefold higher than that of TxB2 regardless of labeling with [3H]arachidonic acid (AA) or [14C]AA. Cells that were pulse-labeled for 2 hr with [3H]AA demonstrated a decreasing PGE2 specific activity over 24 hr, whereas the TxB2 specific activity remained unchanged. In contrast, cells continuously exposed to [14C]AA demonstrated an increasing TxB2 specific activity that approached the level of PGE2 by 24 hr. These results suggest the presence of at least 2 cyclooxygenase metabolic compartments in counterflow-isolated monocytes. Although freshly isolated monocytes have been reported to contain variable numbers of adherent platelets, additional experiments demonstrated that counterflow-isolated platelets are not capable of releasing elevated levels of TxB2 or PGE2 when treated with LPS. It is proposed from these findings that at least two subsets of monocytes exist in peripheral blood that can be distinguished on the basis of independent conversion of AA to TxB2 and PGE2

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...

The effect of carbohydrate and fat variation in euenergetic diets on postabsorptive free fatty acid release

NARCIS (Netherlands)

Bisschop, PH; Ackermans, MT; Endert, E; Ruiter, AFC; Meijer, AJ; Kuipers, F; Sauerwein, HP; Romijn, JA

Diet composition and energy content modulate free fatty acid (FFA) release. The aim of this study was to evaluate the dose-response effects of euenergetic variations in dietary carbohydrate and fat content on postabsorptive FFA release. The rate of appearance (R-a) of palmitate was measured by

An evaluation of trace element release associated with acid mine drainage

International Nuclear Information System (INIS)

Sullivan, P.J.; Yelton, J.L.

1988-01-01

The determination of trace element release from geologic materials, such as oil shale and coal overburden, is important for proper solid waste management planning. The objective of this study was to determine a correlation between release using the following methods: (1) sequential selective dissolution for determining trace element residencies, (2) toxicity characteristic leaching procedure (TCLP), and (3) humidity cell weathering study simulating maximum trace element release. Two eastern oil shales were used, a New Albany shale that contains 4.6 percent pyrite, and a Chattanooga shale that contains 1.5 percent pyrite. Each shale was analyzed for elemental concentrations by soluble, adsorbed, organic, carbonate, and sulfide phases. The results of the results of the selective dissolution studies show that each trace element has a unique distribution between the various phases. Thus, it is possible to predict trace element release based on trace element residency. The TCLP results show that this method is suitable for assessing soluble trace element release but does not realistically assess potential hazards. The results of the humidity cell studies do demonstrate a more reasonable method for predicting trace element release and potential water quality hazards. The humidity cell methods, however, require months to obtain the required data with a large number of analytical measurements. When the selective dissolution data are compared to the trace element concentrations in the TCLP and humidity cell leachates, it is shown that leachate concentrations are predicted by the selective dissolution data. Therefore, selective dissolution may represent a rapid method to assess trace element release associated with acid mine drainage

Autoradiographic observations of the induced vascular injuries by arachidonic acid in rabbit's brain and lung using 111In-oxine labeled platelets

International Nuclear Information System (INIS)

Fujimoto, Tsukasa; Fukushima, Yoshiharu; Suzuki, Hidenori; Kuroiwa, Kyoko; Tanoue, Kenjiro; Yamazaki, Hiroh.

1985-01-01

Autoradiography using 111 In-oxine labeled autologous platelets was performed to observe the behavior of platelets in induced vascular injury by activated platelets in rabbit's brain and lung. Cerebrovascular injuries were induced by injection of arachidonic acid (AA) (0.7 mg/kg) into right internal carotid artery. Fourteen animals were pretreated with antiplatelet drug, ticlopidine (200 mg/kg) and 10 were controls. Before the AA injection, 111 In-oxine (300 μCi) labeled platelets were injected intravenously. Evans blue was given as a marker of disturbances of blood brain barrier. Sixty min after the AA injection, brains were removed and autoradiographic and electron microscopic studies were done. In the nontreated animals and some of the treated animals whose platelet aggregability was not suppressed, blue staining were seen in the cerebral hemisphere of injection side and hot radioactivity in autoradiogram were revealed in corresponding area. In the treated animals whose platelet aggregability was remarkably suppressed, no or slight blue staining or radioactivity were recognized. Only in hot radioactive area, platelet thrombi and vascular injuries were seen. Vascular injuries of lung were produced by decompression after keeping animals under hyperbalic condition (6 atomosphere absolute for 40 min). Before this procedure, 111 In-oxine labeled platelets were injected. Lungs of both 4 control and 4 decompression sickness animals were removed and autoradiographic and lightmicroscopic observations were performed. In lungs of decompression sickness animals remarkable spotty high radioactivity and prominent platelet aggregates in the vessels were seen. These findings were not seen in control animals. Our results suggested important roles of platelets in induced vascular injuries. And this autoradiographic approach seemed to be quite useful for observation of platelet's behavior in injured vessels and evaluation of antiplatelet drugs. (author)

Effects of omega-3 fatty acids on regulatory T cells in hematologic neoplasms

Directory of Open Access Journals (Sweden)

Dayanne da Silva Borges Betiati

2013-01-01

Full Text Available The development of leukemia and lymphomas is related to the increase in inflammatory process modulators. These, in turn, have divergent actions on the neoplastic process. Populations of T cells have different roles in the neoplastic environment; while interferon-gamma positive T cells have antitumor activity, the FoxP3+interleukin-10 positive population present a pro-tumor activity. Simultaneously, the inflammatory process promotes the mobilization of fatty acids from the cell membrane to produce lipid mediators, which also participate of the inflammatory response. Eicosapentaenoic (EPA and docosahexaenoic (DHA omega-3 fatty acids, when incorporated in the plasmatic membrane, decrease the arachidonic acid (AA metabolism and the production of eicosanoids derived from it. Thus, an alternative family of lipid mediators are produced that are often less inflammatory than those produced from arachidonic acid. Fatty acids can also influence the production of peptide mediators such as cytokines, and the expression of transcription factors, which can determine the production patterns of eicosanoids and cytokines as well as cell differentiation. Due to these properties, the objective of this literature review was to investigate studies published over the last 15 years on the effects of using omega-3 fatty acids on inflammatory markers in leukemia and lymphomas.

Release of Water Soluble Drugs from Dynamically Swelling POLY(2-HYDROXYETHYL Methacrylate - CO - Methacrylic Acid) Hydrogels.

Science.gov (United States)

Kou, Jim Hwai-Cher

In this study, ionizable copolymers of HEMA and methacrylic acid (MA) are investigated for their potential use in developing pH dependent oral delivery systems. Because of the MA units, these gels swell extensively at high pH. Since solute diffusion in the hydrophilic polymers depends highly on the water content of the matrix, it is anticipated that the release rate will be modulated by this pH induced swelling. From a practical point of view, the advantage of the present system is that one can minimize drug loss in the stomach and achieve a programmed release in intestine. This approach is expected to improve delivery of acid labile drugs or drugs that cause severe gastrointestinal side effects. This work mainly focuses on the basic understanding of the mechanism involved in drug release from the poly(HEMA -co- MA) gels, especially under dynamic swelling conditions. Equilibrium swelling is first characterized since water content is the major determinant of transport properties in these gels. Phenylpropanolamine (PPA) is chosen as the model drug for the release study and its diffusion characteristics in the gel matrix determined. The data obtained show that the PPA diffusivity follows the free volume theory of Yasuda, which explains the accelerating effect of swelling on drug release. A mathematical model based on a diffusion mechanism has been developed to describe PPA release from the swelling gels. Based on this model, several significant conclusions can be drawn. First, the release rate can be modulated by the aspect ratio of the cylindrical geometry, and this has a practical implication in dosage form design. Second, the release rate can be lowered quite considerably if the dimensional increase due to swelling is significant. Consequently, it is the balance between the drug diffusivity increase and the gel dimensional growth that determines the release rate from the swelling matrix. Third, quasi-steady release kinetics, which are characteristic of swelling

Omega-6 fatty acid biomarkers and incident type 2 diabetes: Pooled analysis of individual-level data for 39740 adults from 20 prospective cohort studies

Science.gov (United States)

The metabolic effects of omega-6 polyunsaturated fatty acids (PUFAs) remain contentious, and little evidence is available regarding their potential role in primary prevention of type 2 diabetes. We aimed to assess the associations of linoleic acid and arachidonic acid biomarkers with incident type 2...

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

International Nuclear Information System (INIS)

Wu Defeng; Cederbaum, Arthur

2006-01-01

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

Metabolomics of Dietary Fatty Acid Restriction in Patients with Phenylketonuria

Science.gov (United States)

Mütze, Ulrike; Beblo, Skadi; Kortz, Linda; Matthies, Claudia; Koletzko, Berthold; Bruegel, Mathias; Rohde, Carmen; Thiery, Joachim; Kiess, Wieland; Ceglarek, Uta

2012-01-01

Background Patients with phenylketonuria (PKU) have to follow a lifelong phenylalanine restricted diet. This type of diet markedly reduces the intake of saturated and unsaturated fatty acids especially long chain polyunsaturated fatty acids (LC-PUFA). Long-chain saturated fatty acids are substrates of mitochondrial fatty acid oxidation for acetyl-CoA production. LC-PUFA are discussed to affect inflammatory and haemostaseological processes in health and disease. The influence of the long term PKU diet on fatty acid metabolism with a special focus on platelet eicosanoid metabolism has been investigated in the study presented here. Methodology/Principal Findings 12 children with PKU under good metabolic control and 8 healthy controls were included. Activated fatty acids (acylcarnitines C6–C18) in dried blood and the cholesterol metabolism in serum were analyzed by liquid chromatographic tandem mass spectrometry (LC-MS/MS). Fatty acid composition of plasma glycerophospholipids was determined by gas chromatography. LC-PUFA metabolites were analyzed in supernatants by LC-MS/MS before and after platelet activation and aggregation using a standardized protocol. Patients with PKU had significantly lower free carnitine and lower activated fatty acids in dried blood compared to controls. Phytosterols as marker of cholesterol (re-) absorption were not influenced by the dietary fatty acid restriction. Fatty acid composition in glycerophospholipids was comparable to that of healthy controls. However, patients with PKU showed significantly increased concentrations of y-linolenic acid (C18:3n-6) a precursor of arachidonic acid. In the PKU patients significantly higher platelet counts were observed. After activation with collagen platelet aggregation and thromboxane B2 and thromboxane B3 release did not differ from that of healthy controls. Conclusion/Significance Long-term dietary fatty acid restriction influenced the intermediates of mitochondrial beta-oxidation. No functional

Metabolomics of dietary fatty acid restriction in patients with phenylketonuria.

Directory of Open Access Journals (Sweden)

Ulrike Mütze

Full Text Available BACKGROUND: Patients with phenylketonuria (PKU have to follow a lifelong phenylalanine restricted diet. This type of diet markedly reduces the intake of saturated and unsaturated fatty acids especially long chain polyunsaturated fatty acids (LC-PUFA. Long-chain saturated fatty acids are substrates of mitochondrial fatty acid oxidation for acetyl-CoA production. LC-PUFA are discussed to affect inflammatory and haemostaseological processes in health and disease. The influence of the long term PKU diet on fatty acid metabolism with a special focus on platelet eicosanoid metabolism has been investigated in the study presented here. METHODOLOGY/PRINCIPAL FINDINGS: 12 children with PKU under good metabolic control and 8 healthy controls were included. Activated fatty acids (acylcarnitines C6-C18 in dried blood and the cholesterol metabolism in serum were analyzed by liquid chromatographic tandem mass spectrometry (LC-MS/MS. Fatty acid composition of plasma glycerophospholipids was determined by gas chromatography. LC-PUFA metabolites were analyzed in supernatants by LC-MS/MS before and after platelet activation and aggregation using a standardized protocol. Patients with PKU had significantly lower free carnitine and lower activated fatty acids in dried blood compared to controls. Phytosterols as marker of cholesterol (re- absorption were not influenced by the dietary fatty acid restriction. Fatty acid composition in glycerophospholipids was comparable to that of healthy controls. However, patients with PKU showed significantly increased concentrations of y-linolenic acid (C18:3n-6 a precursor of arachidonic acid. In the PKU patients significantly higher platelet counts were observed. After activation with collagen platelet aggregation and thromboxane B(2 and thromboxane B(3 release did not differ from that of healthy controls. CONCLUSION/SIGNIFICANCE: Long-term dietary fatty acid restriction influenced the intermediates of mitochondrial beta

Omega-6 fatty acid biomarkers and incident type 2 diabetes : pooled analysis of individual-level data for 39 740 adults from 20 prospective cohort studies

NARCIS (Netherlands)

Wu, Jason H.Y.; Marklund, Matti; Imamura, Fumiaki; Tintle, Nathan; Ardisson Korat, Andres V.; de Goede, Janette; Zhou, Xia; Yang, Wei Sin; de Oliveira Otto, Marcia C.; Kröger, Janine; Qureshi, Waqas; Virtanen, Jyrki K.; Bassett, Julie K.; Frazier-Wood, Alexis C.; Lankinen, Maria; Murphy, Rachel A.; Rajaobelina, Kalina; Del Gobbo, Liana C.; Forouhi, Nita G.; Luben, Robert; Khaw, Kay Tee; Wareham, Nick; Kalsbeek, Anya; Veenstra, Jenna; Luo, Juhua; Hu, Frank B.; Lin, Hung Ju; Siscovick, David S.; Boeing, Heiner; Chen, Tzu An; Steffen, Brian; Steffen, Lyn M.; Hodge, Allison; Eriksdottir, Gudny; Smith, Albert V.; Gudnason, Vilmunder; Harris, Tamara B.; Brouwer, Ingeborg A.; Berr, Claudine; Helmer, Catherine; Samieri, Cecilia; Laakso, Markku; Tsai, Michael Y.; Giles, Graham G.; Nurmi, Tarja; Wagenknecht, Lynne; Schulze, Matthias B.; Lemaitre, Rozenn N.; Chien, Kuo Liong; Soedamah-Muthu, Sabita S.; Geleijnse, Johanna M.; Sun, Qi; Harris, William S.; Lind, Lars; Ärnlöv, Johan; Riserus, Ulf; Micha, Renata; Mozaffarian, Dariush

2017-01-01

Background The metabolic effects of omega-6 polyunsaturated fatty acids (PUFAs) remain contentious, and little evidence is available regarding their potential role in primary prevention of type 2 diabetes. We aimed to assess the associations of linoleic acid and arachidonic acid biomarkers with

Fatty Acid Modulation of the Endocannabinoid System and the Effect on Food Intake and Metabolism

Directory of Open Access Journals (Sweden)

Shaan S. Naughton

2013-01-01

Full Text Available Endocannabinoids and their G-protein coupled receptors (GPCR are a current research focus in the area of obesity due to the system’s role in food intake and glucose and lipid metabolism. Importantly, overweight and obese individuals often have higher circulating levels of the arachidonic acid-derived endocannabinoids anandamide (AEA and 2-arachidonoyl glycerol (2-AG and an altered pattern of receptor expression. Consequently, this leads to an increase in orexigenic stimuli, changes in fatty acid synthesis, insulin sensitivity, and glucose utilisation, with preferential energy storage in adipose tissue. As endocannabinoids are products of dietary fats, modification of dietary intake may modulate their levels, with eicosapentaenoic and docosahexaenoic acid based endocannabinoids being able to displace arachidonic acid from cell membranes, reducing AEA and 2-AG production. Similarly, oleoyl ethanolamide, a product of oleic acid, induces satiety, decreases circulating fatty acid concentrations, increases the capacity for β-oxidation, and is capable of inhibiting the action of AEA and 2-AG in adipose tissue. Thus, understanding how dietary fats alter endocannabinoid system activity is a pertinent area of research due to public health messages promoting a shift towards plant-derived fats, which are rich sources of AEA and 2-AG precursor fatty acids, possibly encouraging excessive energy intake and weight gain.

Interleukin-2 stimulates osteoclastic activity: Increased acid production and radioactive calcium release

International Nuclear Information System (INIS)

Ries, W.L.; Seeds, M.C.; Key, L.L.

1989-01-01

Recombinant human interleukin-2 (IL-2) was studied to determine effects on acid production by individual osteoclasts in situ on mouse calvarial bones. This analysis was performed using a microspectrofluorimetric technique to quantify acid production in individual cells. Radioactive calcium release was determined using calvarial bones in a standard tissue culture system. This allowed us to correlate changes in acid production with a measure of bone resorption. IL-2 stimulated acid production and bone resorbing activity. Both effects were inhibited by calcitonin. No stimulation of bone resorption occurred when IL-2-containing test media was incubated with a specific anti-IL-2 antibody and ultrafiltered. Our data demonstrated a correlation between acid production and bone resorbing activity in mouse calvaria exposed to parathyroid hormone (PTH). The data obtained from cultured mouse calvaria exposed to IL-2 demonstrated similar stimulatory effects to those seen during PTH exposure. These data suggest that calvaria exposed to IL-2 in vitro have increased osteoclastic acid production corresponding with increased bone resorption. (author)

Acid and stretch, but not capsaicin, are effective stimuli for ATP release in the porcine bladder mucosa: Are ASIC and TRPV1 receptors involved?

Science.gov (United States)

Sadananda, Prajni; Kao, Felicity C L; Liu, Lu; Mansfield, Kylie J; Burcher, Elizabeth

2012-05-15

Stretch-evoked ATP release from the bladder mucosa is a key event in signaling bladder fullness. Our aim was to examine whether acid and capsaicin can also release ATP and to determine the receptors involved, using agonists and antagonists at TRPV1 and acid-sensing ion channels (ASICs). Strips of porcine bladder mucosa were exposed to acid, capsaicin or stretch. Strip tension was monitored. Bath fluid was collected for ATP measurement. Gene expression of ASICs and TRPV1 in porcine bladders was quantified using quantitative real-time PCR (qRT-PCR). Stretch stimulus (150% of original length) repeatedly and significantly increased ATP release to approximately 45 times basal release. Acid (pH 6.5, 6.0, 5.6) contracted mucosal strips and also increased ATP release up to 30-fold, without evidence of desensitization. Amiloride (0.3 μM) reduced the acid-evoked ATP release by approximately 70%, while capsazepine (10 μM) reduced acid-evoked ATP release at pH 6.0 and pH 5.6 (by 68% and 61%, respectively). Capsaicin (0.1-10 μM) was ineffective in causing ATP release, and also failed to contract porcine mucosal or detrusor strips. Gene expression for ASIC1, ASIC2, ASIC3 and TRPV1 was seen in the lateral wall, dome, trigone and neck of both detrusor and mucosa. In conclusion, stretch and acid induce ATP release in the porcine bladder mucosa, but capsaicin is ineffective. The pig bladder is a well-known model for the human bladder, however these data suggest that it should be used with caution, particularly for TRPV1 related studies. Copyright © 2012 Elsevier B.V. All rights reserved.

Risk of hydrocyanic acid release in the electroplating industry.

Science.gov (United States)

Piccinini, N; Ruggiero, G N; Baldi, G; Robotto, A

2000-01-07

This paper suggests assessing the consequences of hydrocyanic acid (HCN) release into the air by aqueous cyanide solutions in abnormal situations such as the accidental introduction of an acid, or the insertion of a cyanide in a pickling bath. It provides a well-defined source model and its resolution by methods peculiar to mass transport phenomena. The procedure consists of four stages: calculation of the liquid phase concentration, estimate of the HCN liquid-vapour equilibrium, determination of the mass transfer coefficient at the liquid-vapour interface, evaluation of the air concentration of HCN and of the damage distances. The results show that small baths operating at high temperatures are the major sources of risk. The building up of lethal air concentrations, on the other hand, is governed by the values of the mass transfer coefficient, which is itself determined by the flow dynamics and bath geometry. Concerning the magnitude of the risk, the fallout for external emergency planning is slight in all the cases investigated.

A radiochemical assay for detection of leukotriene B4 production from isolated cells

International Nuclear Information System (INIS)

Aharony, D.; Dobson, P.; Krell, R.D.

1984-01-01

A radiochemical procedure for quantitating the effect of inhibitors of leukotriene B4 (LTB4) biosynthesis is described. Rat peritoneal cells were labeled with 3 H-arachidonic acid and stimulated with the calcium ionophore A23187. 3 H-LTB4 was isolated by processing on C18-Sep Pak cartridges followed by reverse-phase high pressure liquid chromatography (HPLC). The identity of this product, as well as other arachidonic acid metabolites, was verified by using silicic acid column chromatography followed by straight-phase HPLC and thin layer chromatography. Using this assay, LTB4 release by ionophore A23187 has been shown to be both time- and concentration-dependent. Indomethacin enhanced, while NDGA and ETYA inhibited, the A23187-induced production of LTB4. This procedure is both simple and direct and is capable of assessing the ability of novel compounds to alter LTB4 production

Development of paradigm for the study of amino acid neurotransmitter release in human autopsy brain samples

International Nuclear Information System (INIS)

Kuo, K.-W.; Dodd, P.R.

2001-01-01

Full text: This study attempted to establish a release protocol to characterize both the vesicular and cytoplasmic components of amino acid transmitter release in human synaptosomes. Experiments with rat synaptosomes showed that, with depolarizing concentrations of K + ions, vesicular release could be successfully differentiated from cytoplasmic release for preloaded L-[ 3 H ]glutamate and [ 14 C ]GABA. However, human tissue studies did not give clear-cut results. Experiments were carried out to optimize the release paradigm as well as to improve the vesicular uptake of labeled transmitters. A 'pulse- chase' protocol, with an unlabelled D-aspartate chase, was performed in human tissue samples in order to enhance the L-[ 3 H ] glutamate release signal derived from exocytosis by removing the cytoplasmic pool of L-[ 3 H ] glutamate first. However, the results showed that total release was not enhanced effectively in comparison with the non-pulse-chase protocol. In brief, the pulse-chase protocol did not build up the vesicular pool of L-[ 3 H ]glutamate, though the cytoplasmic L- [ 3 H ] glutamate pool was effectively depressed by D-aspartate. Further studies applied 4- aminopyridine (4-AP) to trigger release, to circumvent the problem of the reversal of plasma membrane transporters caused by raised K + ion concentrations. The results showed that the application of 4-AP elicited the release of amino acid transmitters from rat synaptosomes, but failed to produce successful release signals in the human tissue experiments. Our findings suggest that the vesicular compartment may be impaired by freezing and affected by post-mortem delay (PMD). Rat studies showed that the freezing step had a major effect on Ca 2+-dependent release, as less L- [3 H ]glutamate and [ 14 C ]GABA were released from the frozen rat tissue preparations. Moreover, there was an indication of a decline in L-[ 3 H ]glutamate release with increasing PMD. Copyright (2001) Australian Neuroscience Society

Targeting thyroid cancer with acid-triggered release of doxorubicin from silicon dioxide nanoparticles

Directory of Open Access Journals (Sweden)

Li SJ

2017-08-01

Full Text Available Shijie Li,1 Daqi Zhang,1 Shihou Sheng,2 Hui Sun1 1Department of Thyroid Surgery, 2Department of Gastrointestinal Colorectal and Anal Surgery, China–Japan Union Hospital of Jilin University, Chang Chun, People’s Republic of China Abstract: Currently, therapy for thyroid cancer mainly involves surgery and radioiodine therapy. However, chemotherapy can be used in advanced and aggressive thyroid cancer that cannot be treated by other options. Nevertheless, a major obstacle to the successful treatment of thyroid cancer is the delivery of drugs to the thyroid gland. Here, we present an example of the construction of silicon dioxide nanoparticles with thyroid–stimulating-hormone receptor-targeting ligand that can specifically target the thyroid cancer. Doxorubicin nanoparticles can be triggered by acid to release the drug payload for cancer therapy. These nanoparticles shrink the tumor size in vivo with less toxic side effects. This research paves the way toward effective chemotherapy for thyroid cancer. Keywords: thyroid cancer, silicon dioxide nanoparticle, doxorubicin, acid-triggered release

Effects of undecylenic acid released from denture liner on Candida biofilms.

Science.gov (United States)

Gonçalves, L M; Del Bel Cury, A A; Sartoratto, A; Garcia Rehder, V L; Silva, W J

2012-10-01

Denture liners (DL) are easily colonized by Candida spp. In an attempt to prevent biofilm colonization, manufacturers have incorporated undecylenic acid (UDA) into DL. In this in vitro study, the effects of UDA released from DL on Candida biofilms were investigated. The concentrations of UDA released from commercial DL were determined by gas chromatography-mass spectrometry (GC-MS). Minimum inhibitory concentration (MIC) and minimum fungistatic concentration (MFC) tests were performed for C. albicans or C. glabrata, with UDA for comparison with the concentrations released from DL. Specimens of DL with (experimental group) and without UDA (control group) were fabricated, and Candida biofilms were developed on DL surfaces. Biofilms were evaluated by cell counts, metabolic activity, structure, and secretion of proteinase or phospholipase. The concentrations of UDA released were within the MIC and MFC ranges. In the presence of UDA, C. albicans biofilms were thinner and had lower numbers of viable and active cells, although no significant enzymatic changes were observed relative to the control group (p > 0.05). In contrast, C. glabrata biofilms exhibited higher cell counts and greater metabolic activity and also increased proteinase activity in the presence of UDA relative to the control group (p < 0.05). Overall, UDA did not prevent Candida biofilm formation.

Sustained release of nucleic acids from polymeric nanoparticles using microemulsion precipitation in supercritical carbon dioxide.

Science.gov (United States)

Ge, Jun; Jacobson, Gunilla B; Lobovkina, Tatsiana; Holmberg, Krister; Zare, Richard N

2010-12-21

A general approach for producing biodegradable nanoparticles for sustained nucleic acid release is presented. The nanoparticles are produced by precipitating a water-in-oil microemulsion in supercritical CO(2). The microemulsion consists of a transfer RNA aqueous solution (water phase), dichloromethane containing poly(l-lactic acid)-poly(ethylene glycol) (oil phase), the surfactant n-octyl β-D-glucopyranoside, and the cosurfactant n-butanol.

Stimulation of prostaglandin E2 production by phorbol esters and epidermal growth factor in porcine thyroid cells

International Nuclear Information System (INIS)

Kasai, K.; Hiraiwa, M.; Emoto, T.; Akimoto, K.; Takaoka, T.; Shimoda, S.I.

1987-01-01

Effects of phorbol esters and epidermal growth factor (EGF) on prostaglandin E 2 production by cultured porcine thyroid cells were examined. Both phorbol 12-myristate 13-acetate (PMA) and EGF stimulated prostaglandin E 2 production by the cells in dose related fashion. PMA stimulated prostaglandin E 2 production over fifty-fold with the dose of 10 -7 M compared with control. EGF (10 -7 M) also stimulated it about ten-fold. The ED 50 values of PMA and EGF were respectively around 1 x 10 -9 M and 5 x 10 -10 M. Thyroid stimulating hormone (TSH), however, did not stimulate prostaglandin E 2 production from 1 to 24-h incubation. The release of radioactivity from [ 3 H]-arachidonic acid prelabeled cells was also stimulated by PMA and EGF, but not by TSH. These results indicate that both PMA and EGF are potent stimulators of prostaglandin E 2 production, associated with the activity to stimulate arachidonic acid release in porcine thyroid cells. 36 references, 2 figures, 1 table

Biodegradable hyaluronic acid hydrogels to control release of dexamethasone through aqueous Diels–Alder chemistry for adipose tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Fan, Ming; Ma, Ye; Zhang, Ziwei; Mao, Jiahui [School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing (China); Tan, Huaping, E-mail: hptan@njust.edu.cn [School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing (China); Hu, Xiaohong [School of Material Engineering, Jinling Institute of Technology, Nanjing (China)

2015-11-01

A robust synthetic strategy of biopolymer-based hydrogels has been developed where hyaluronic acid derivatives reacted through aqueous Diels–Alder chemistry without the involvement of chemical catalysts, allowing for control and sustain release of dexamethasone. To conjugate the hydrogel, furan and maleimide functionalized hyaluronic acid were synthesized, respectively, as well as furan functionalized dexamethasone, for the covalent immobilization. Chemical structure, gelation time, morphologies, swelling kinetics, weight loss, compressive modulus and dexamethasone release of the hydrogel system in PBS at 37 °C were studied. The results demonstrated that the aqueous Diels–Alder chemistry provides an extremely selective reaction and proceeds with high efficiency for hydrogel conjugation and covalent immobilization of dexamethasone. Cell culture results showed that the dexamethasone immobilized hydrogel was noncytotoxic and preserved proliferation of entrapped human adipose-derived stem cells. This synthetic approach uniquely allows for the direct fabrication of biologically functionalized gel scaffolds with ideal structures for adipose tissue engineering, which provides a competitive alternative to conventional conjugation techniques such as copper mediated click chemistry. - Highlights: • A biodegradable hyaluronic acid hydrogel was crosslinked via aqueous Diels–Alder chemistry. • Dexamethasone was covalently immobilized into the hyaluronic acid hydrogel via aqueous Diels–Alder chemistry. • Dexamethasone could be released from the Diels–Alder hyaluronic acid hydrogel in a controlled fashion.

Biodegradable hyaluronic acid hydrogels to control release of dexamethasone through aqueous Diels–Alder chemistry for adipose tissue engineering

International Nuclear Information System (INIS)

Fan, Ming; Ma, Ye; Zhang, Ziwei; Mao, Jiahui; Tan, Huaping; Hu, Xiaohong

2015-01-01

A robust synthetic strategy of biopolymer-based hydrogels has been developed where hyaluronic acid derivatives reacted through aqueous Diels–Alder chemistry without the involvement of chemical catalysts, allowing for control and sustain release of dexamethasone. To conjugate the hydrogel, furan and maleimide functionalized hyaluronic acid were synthesized, respectively, as well as furan functionalized dexamethasone, for the covalent immobilization. Chemical structure, gelation time, morphologies, swelling kinetics, weight loss, compressive modulus and dexamethasone release of the hydrogel system in PBS at 37 °C were studied. The results demonstrated that the aqueous Diels–Alder chemistry provides an extremely selective reaction and proceeds with high efficiency for hydrogel conjugation and covalent immobilization of dexamethasone. Cell culture results showed that the dexamethasone immobilized hydrogel was noncytotoxic and preserved proliferation of entrapped human adipose-derived stem cells. This synthetic approach uniquely allows for the direct fabrication of biologically functionalized gel scaffolds with ideal structures for adipose tissue engineering, which provides a competitive alternative to conventional conjugation techniques such as copper mediated click chemistry. - Highlights: • A biodegradable hyaluronic acid hydrogel was crosslinked via aqueous Diels–Alder chemistry. • Dexamethasone was covalently immobilized into the hyaluronic acid hydrogel via aqueous Diels–Alder chemistry. • Dexamethasone could be released from the Diels–Alder hyaluronic acid hydrogel in a controlled fashion

Nucleic acid therapeutic carriers with on-demand triggered release.

Science.gov (United States)

Venkatesh, Siddarth; Wower, Jacek; Byrne, Mark E

2009-09-01

Biohybrid platforms such as synthetic polymer networks engineered from artificial and natural materials hold immense potential as drug and gene delivery vehicles. Here, we report the synthesis and characterization of novel polymer networks that release oligonucleotide sequences via enzymatic and physical triggers. Chemical monomers and acrylated oligonucleotides were copolymerized into networks, and phosphoimaging revealed that 70% of the oligonucleotides were incorporated into the networks. We observed that the immobilized oligonucleotides were readily cleaved when the networks were incubated with the type II restriction enzyme BamHI. The diffusion of the cleaved fragments through the macromolecular chains resulted in relatively constant release profiles very close to zero-order. To our knowledge, this is the first study which harnesses the sequence-specificity of restriction endonucleases as triggering agents for the cleavage and release of oligonucleotide sequences from a synthetic polymer network. The polymer networks exhibited an oligonucleotide diffusion coefficient of 5.6 x 10(-8) cm(2)/s and a diffusional exponent of 0.92. Sigmoidal temperature responsive characteristics of the networks matched the theoretical melting temperature of the oligonucleotides and indicated a cooperative melting transition of the oligonucleotides. The networks were also triggered to release a RNA-cleaving deoxyribozyme, which degraded a HIV-1 mRNA transcript in vitro. To tailor release profiles of the oligonucleotides, we controlled the structure of the macromolecular architecture of the networks by varying their cross-linking content. When incubated with DNase I, networks of cross-linking content 0.15%, 0.22%, and 0.45% exhibited oligonucleotide diffusion coefficients of 1.67 x 10(-8), 7.65 x 10(-9), and 2.7 x 10(-9) cm(2)/s, and diffusional exponents of 0.55, 0.8, and 0.8, respectively. The modular nature of our platform promises to open new avenues for the creation and

Maslinic acid modulates secreted phospholipase A2-IIA (sPLA2-IIA ...

Indian Academy of Sciences (India)

Wei Hsum Yap

2018-03-29

Mar 29, 2018 ... Further analysis revealed that sPLA2-IIA only induced modest LDL oxidation and that inhibitory .... COX-2, was also reduced in primary human chondrocyte, primary rat .... oxidation (4.34 nmol MDA/mg protein) compared to native ..... rheumatoid fibroblast-like synoviocyte arachidonic acid meta- bolism.

Decapeptides as effective agonists from L-amino acids biologically equivalent to the luteinizing hormone-releasing hormone

International Nuclear Information System (INIS)

Folkers, K.; Bowers, C.Y.; Tang, P.L.; Kubota, M.

1986-01-01

Apparently, no agonist has been found that is comparable in potency to the luteinizing hormone-releasing hormone (LHRH) for release of LH and follicle-stimulating hormone (FSH) without substitutions with unnatural or D forms of natural amino acids. Of 139 known agonist analogs of LHRH, two were active in the range of 65%. The four LHRHs known to occur in nature involve a total of six amino acids (Tyr, His, Leu, Trp, Arg, Gln) in positions 5, 7, and 8. There are 16 possible peptides with these six amino acids in positions 5, 7, and 8, of which 4 are the known LHRHs, and 2 more were synthesized. The authors have synthesized the 10 new peptides and assayed 11 in vivo and in vitro, and they found not only 1 but a total of 5 that have activity equivalent to or greater than that of LHRH for the release of LH and/or FSH under at least one assay condition. These five are as follows: [His 5 ,Trp 7 ,Gln 8 ]LHRH; [His 5 ,Trp 7 ,Leu 8 ]LHRH; [His 5 ,Trp 7 ]LHRH; [Trp 7 ]LHRH; [His 5 ]LHRH. These structures are a basis for the design of antagonists without Arg 8 toward avoiding histamine release. Complete inhibition of LH and FSH release in vivo may be induced by joint use of Arg 8 and Gln 8 or Leu 8 antagonists. These potent agonists, related to LHRH, may be therapeutically useful in disorders of reproduction, the central nervous system, and for the control of hormone-dependent carcinomas. Radioreceptor assays and radioimmunoassays were utilized

Photolabile protection for amino acids: studies on the release from novel benzoquinolone cages.

Science.gov (United States)

Fonseca, Andrea S C; Soares, Ana M S; Gonçalves, M Sameiro T; Costa, Susana P G

2015-12-01

The synthesis of a novel fused nitrogen heterocycle, benzoquinolone, for evaluation as a photocleavable protecting group is described for the first time by coupling to model amino acids (alanine, phenylalanine and glutamic acid). Conversion of the phenylalanine ester conjugate to the thionated derivative was accomplished by reaction with Lawesson's reagent. Photocleavage studies of the carbonyl and thiocarbonyl benzoquinolone conjugates in various solvents and at different wavelengths (300, 350 and 419 nm) showed that the most interesting result was obtained at 419 nm for the thioconjugate, revealing that the presence of the thiocarbonyl group clearly improved the photolysis rates, giving practicable irradiations times for the release of the amino acids (less than 1 min).

Generation, Release, and Uptake of the NAD Precursor Nicotinic Acid Riboside by Human Cells.

Science.gov (United States)

Kulikova, Veronika; Shabalin, Konstantin; Nerinovski, Kirill; Dölle, Christian; Niere, Marc; Yakimov, Alexander; Redpath, Philip; Khodorkovskiy, Mikhail; Migaud, Marie E; Ziegler, Mathias; Nikiforov, Andrey

2015-11-06

NAD is essential for cellular metabolism and has a key role in various signaling pathways in human cells. To ensure proper control of vital reactions, NAD must be permanently resynthesized. Nicotinamide and nicotinic acid as well as nicotinamide riboside (NR) and nicotinic acid riboside (NAR) are the major precursors for NAD biosynthesis in humans. In this study, we explored whether the ribosides NR and NAR can be generated in human cells. We demonstrate that purified, recombinant human cytosolic 5'-nucleotidases (5'-NTs) CN-II and CN-III, but not CN-IA, can dephosphorylate the mononucleotides nicotinamide mononucleotide and nicotinic acid mononucleotide (NAMN) and thus catalyze NR and NAR formation in vitro. Similar to their counterpart from yeast, Sdt1, the human 5'-NTs require high (millimolar) concentrations of nicotinamide mononucleotide or NAMN for efficient catalysis. Overexpression of FLAG-tagged CN-II and CN-III in HEK293 and HepG2 cells resulted in the formation and release of NAR. However, NAR accumulation in the culture medium of these cells was only detectable under conditions that led to increased NAMN production from nicotinic acid. The amount of NAR released from cells engineered for increased NAMN production was sufficient to maintain viability of surrounding cells unable to use any other NAD precursor. Moreover, we found that untransfected HeLa cells produce and release sufficient amounts of NAR and NR under normal culture conditions. Collectively, our results indicate that cytosolic 5'-NTs participate in the conversion of NAD precursors and establish NR and NAR as integral constituents of human NAD metabolism. In addition, they point to the possibility that different cell types might facilitate each other's NAD supply by providing alternative precursors. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Controlled Release of Indomethacin from Smart Starch-Based Hydrogels Prepared Acrylic Acid and b-Cyclodextrin as a Nanocarrier

Directory of Open Access Journals (Sweden)

Hossein Ghasemzadeh Mohammadi

2017-01-01

Full Text Available Controlled release of drugs can reduce the undesired effects of drug level fluctuations, and diminish the side effects as well as improve the therapeutic outcome of the drugs. In recent year, the scope of the drug delivery systems has been greatly expanded by the development of various hydrogels. The present work has focused on the design of a pH sensitive drug delivery system (DDS based on starch, acrylic acid (AA and β-cyclodextrins for controlled delivery of indomethacin. The hydrogels were prepared via graft polymerization of acrylic acid (AA onto starch and β-cyclodextrins backbones by a free radical polymerization technique. Cyclodextrins are able to form water-soluble complexes with many lipophilic water-insoluble drugs. In aqueous solutions, the drug molecules located in the central cavity of the cyclodextrin are in a dynamic equilibrium with free drug molecules. The interaction of drug with the polymer was evidenced by FTIR spectroscopy and thermal gravimetric analysis (TGA. The morphology of the samples was examined by scanning electron microscopy (SEM. The results showed that the hydrogels have good porosity and provided high surface area for the loading and release of drugs. Drug release behavior was carried out at physiological conditions of phosphate buffer, pH 8. In basic pH (like the intestine medium the hydrogels released the indomethacin, but in acidic pH (like the stomach medium there was no tendency to drug release. By increasing the amount of cyclodextrin, the rate of drug loading and release increased due to the dynamic equilibrium and interaction between the loaded drug and the cyclodextrin. This study has demonstrated that the hydrogel matrices are potentially suitable for controlled-release systems.

[Research of preparation craft of Danshen phenolic acid fast release unit in multi-drug delivery system of Tongmai micro-pellets].

Science.gov (United States)

Chen, Bin; Xiao, Wei; Jia, Xiao-Bin; Huang, Yang

2012-07-01

To prepare Danshen phenolic acid fast release micro-pellets and study its preparation craft. The factors which could impact yield, extrude shaping, dissolution of Danshen phenolic acid micro-pellets such as wetting agent, drug loading dose, adjuvant, lactose dose, disintegrant, CMS-Na dose and wetting agent dose was investigated. The optimum preparation craft of Danshen phenolic acid fast release micro-pellets was screened out by orhogonal design. Formula of Danshen phenolic acid fast release micro-pellets was calculated as volume dose 50 g. The formula was as follows: principal agent 22.5 g, lactose 5 g, CMS-Na 2 g, MCC 20.5 g, 27 mL 30% ethanol as wetting agent. Extrusion-spheronization was applied. The optimum conditions were screened out as follows: extrusion frequency (25 Hz), spheronization machine frequency (50 Hz), spheronization time (4 min). The process was scientific and rational. The preparation is stable settles basis for multi-drug delivery system of Tongmai micro-pellets.

The oxygen isotope composition of phosphate released from phytic acid by the activity of wheat and Aspergillus niger phytase

Science.gov (United States)

von Sperber, C.; Tamburini, F.; Brunner, B.; Bernasconi, S. M.; Frossard, E.

2015-07-01

Phosphorus (P) is an essential nutrient for living organisms. Under P-limiting conditions plants and microorganisms can exude extracellular phosphatases that release inorganic phosphate (Pi) from organic phosphorus compounds (Porg). Phytic acid (myo-inositol hexakisphosphate, IP6) is an important form of Porg in many soils. The enzymatic hydrolysis of IP6 by phytase yields available Pi and less phosphorylated inositol derivates as products. The hydrolysis of organic P compounds by phosphatases leaves an isotopic imprint on the oxygen isotope composition (δ18O) of released Pi, which might be used to trace P in the environment. This study aims at determining the effect of phytase on the oxygen isotope composition of released Pi. For this purpose, enzymatic assays with histidine acid phytases from wheat and Aspergillus niger were prepared using IP6, adenosine 5'-monophosphate (AMP) and glycerophosphate (GPO4) as substrates. For a comparison to the δ18O of Pi released by other extracellular enzymes, enzymatic assays with acid phosphatases from potato and wheat germ with IP6 as a substrate were prepared. During the hydrolysis of IP6 by phytase, four of the six Pi were released, and one oxygen atom from water was incorporated into each Pi. This incorporation of oxygen from water into Pi was subject to an apparent inverse isotopic fractionation (ϵ ~ 6 to 10 ‰), which was similar to that imparted by acid phosphatase from potato during the hydrolysis of IP6 (ϵ ~ 7 ‰), where less than three Pi were released. The incorporation of oxygen from water into Pi during the hydrolysis of AMP and GPO4 by phytase yielded a normal isotopic fractionation (ϵ ~ -12 ‰), similar to values reported for acid phosphatases from potato and wheat germ. We attribute this similarity in ϵ to the same amino acid sequence motif (RHGXRXP) at the active site of these enzymes, which leads to similar reaction mechanisms. We suggest that the striking

Effect of molecular weight and glass transition on relaxation and release behaviour of poly(DL-lactic acid) tablets

NARCIS (Netherlands)

Steendam, R.; Van Steenbergen, M.J.; Hennink, W.E.; Frijlink, H.W.; Lerk, C.F.

2001-01-01

Different molecular weight grades of poly(DL-lactic acid) were applied as release controlling excipients in tablets for oral drug administration. The role of molecular weight and glass transition in the mechanism of water-induced volume expansion and drug release of PDLA tablets was investigated.

Modulation of ASIC channels in rat cerebellar purkinje neurons by ischaemia-related signals

Science.gov (United States)

Allen, Nicola J; Attwell, David

2002-01-01

Acid-sensing ion channels (ASICs), activated by a decrease of extracellular pH, are found in neurons throughout the nervous system. They have an amino acid sequence similar to that of ion channels activated by membrane stretch, and have been implicated in touch sensation. Here we characterize the pH-dependent activation of ASICs in cerebellar Purkinje cells and investigate how they are modulated by factors released in ischaemia. Lowering the external pH from 7.4 activated an inward current at −66 mV, carried largely by Na+ ions, which was half-maximal for a step to pH 6.4 and was blocked by amiloride and gadolinium. The H+-gated current desensitized within a few seconds, but approximately 30% of cells showed a sustained inward current (11% of the peak current) in response to the maintained presence of pH 6 solution. The peak H+-evoked current was potentiated by membrane stretch (which occurs in ischaemia when [K+]o rises) and by arachidonic acid (which is released when [Ca2+]i rises in ischaemia). Arachidonic acid increased to 77% the fraction of cells showing a sustained current evoked by acid pH. The ASIC currents were also potentiated by lactate (which is released when metabolism becomes anaerobic in ischaemia) and by FMRFamide (which may mimic the action of related mammalian RFamide transmitters). These data reinforce suggestions of a mechanosensory aspect to ASIC channel function, and show that the activation of ASICs reflects the integration of multiple signals which are present during ischaemia. PMID:12205186

Reversal of reflex pulmonary vasoconstriction induced by main pulmonary arterial distension.

Science.gov (United States)

Juratsch, C E; Grover, R F; Rose, C E; Reeves, J T; Walby, W F; Laks, M M

1985-04-01

Distension of the main pulmonary artery (MPA) induces pulmonary hypertension, most probably by neurogenic reflex pulmonary vasoconstriction, although constriction of the pulmonary vessels has not actually been demonstrated. In previous studies in dogs with increased pulmonary vascular resistance produced by airway hypoxia, exogenous arachidonic acid has led to the production of pulmonary vasodilator prostaglandins. Hence, in the present study, we investigated the effect of arachidonic acid in seven intact anesthetized dogs after pulmonary vascular resistance was increased by MPA distention. After steady-state pulmonary hypertension was established, arachidonic acid (1.0 mg/min) was infused into the right ventricle for 16 min; 15-20 min later a 16-mg bolus of arachidonic acid was injected. MPA distension was maintained throughout the study. Although the infusion of arachidonic acid significantly lowered the elevated pulmonary vascular resistance induced by MPA distension, the pulmonary vascular resistance returned to control levels only after the bolus injection of arachidonic acid. Notably, the bolus injection caused a biphasic response which first increased the pulmonary vascular resistance transiently before lowering it to control levels. In dogs with resting levels of pulmonary vascular resistance, administration of arachidonic acid in the same manner did not alter the pulmonary vascular resistance. It is concluded that MPA distension does indeed cause reflex pulmonary vasoconstriction which can be reversed by vasodilator metabolites of arachidonic acid. Even though this reflex may help maintain high pulmonary vascular resistance in the fetus, its function in the adult is obscure.

Releasing Pattern of Applied Phosphorus and Distribution Change of Phosphorus Fractions in the Acid Upland Soils with Successive Resin Extraction

Directory of Open Access Journals (Sweden)

Arief Hartono

2008-05-01

Full Text Available The releasing pattern of applied P in the acid upland soils and the soil properties influencing the pattern were studied. Surface horizons of six acid upland soils from Sumatra, Java and Kalimantan were used in this study. The releasing pattern of applied P (300 mg P kg-1 of these soils were studied by successive resin extraction. P fractionation was conducted to evaluate which fractions released P to the soil solution after successive resin extraction. The cumulative of resin-Pinorganic (Pi release of soils was fitted to the first order kinetic. Regression analyses using factor scores obtained from the previous principal components analyses was applied to determine soil properties influencing P releasing pattern. The results suggested that the maximum P release was significantly (P < 0.05 increased by acidity plus 1.4 nm mineral-related factor (PC2 i.e. exchangeable Al and 1.4 nm minerals (smectite and vermiculite and decreased by oxide related factor (PC1 i.e. aluminum (Al plus 1/2 iron (Fe (by ammonium oxalate, crystalline Al and Fe oxides, cation exchange capacity, and clay content. P fractionation analysis after successive resin extraction showed that both labile and less labile in the form of NaHCO3-Pi and NaOH-Pi fractions, respectively, can be transformed into resin-Pi when in the most labile resin-Pi is depleted. Most of P released in high oxides soils were from NaOH-Pi fraction while in low oxides soils were from NaHCO3-Pi. P release from the former fraction resulted in the maximum P release lower than that of the latter one. When NaHCO3-Pi was high, NaOH-Pi was relatively more stable than NaHCO3-Pi despite resin-Pi removal. NaHCO3-Pi and NaOH-Pi are very important P fractions in replenishing resin-Pi in these acid upland soils.

The Nitric Oxide Donor SNAP-Induced Amino Acid Neurotransmitter Release in Cortical Neurons. Effects of Blockers of Voltage-Dependent Sodium and Calcium Channels

Science.gov (United States)

Merino, José Joaquín; Arce, Carmen; Naddaf, Ahmad; Bellver-Landete, Victor; Oset-Gasque, Maria Jesús; González, María Pilar

2014-01-01

Background The discovery that nitric oxide (NO) functions as a signalling molecule in the nervous system has radically changed the concept of neuronal communication. NO induces the release of amino acid neurotransmitters but the underlying mechanisms remain to be elucidated. Findings The aim of this work was to study the effect of NO on amino acid neurotransmitter release (Asp, Glu, Gly and GABA) in cortical neurons as well as the mechanism underlying the release of these neurotransmitters. Cortical neurons were stimulated with SNAP, a NO donor, and the release of different amino acid neurotransmitters was measured by HPLC. The involvement of voltage dependent Na+ and Ca2+ channels as well as cGMP in its mechanism of action was evaluated. Conclusions Our results indicate that NO induces release of aspartate, glutamate, glycine and GABA in cortical neurons and that this release is inhibited by ODQ, an inhibitor of soluble guanylate cyclase. Thus, the NO effect on amino acid neurotransmission could be mediated by cGMP formation in cortical neurons. Our data also demonstrate that the Na+ and Ca2+ voltage- dependent calcium channels are involved in the NO effects on cortical neurons. PMID:24598811

The nitric oxide donor SNAP-induced amino acid neurotransmitter release in cortical neurons. Effects of blockers of voltage-dependent sodium and calcium channels.

Science.gov (United States)

Merino, José Joaquín; Arce, Carmen; Naddaf, Ahmad; Bellver-Landete, Victor; Oset-Gasque, Maria Jesús; González, María Pilar

2014-01-01

The discovery that nitric oxide (NO) functions as a signalling molecule in the nervous system has radically changed the concept of neuronal communication. NO induces the release of amino acid neurotransmitters but the underlying mechanisms remain to be elucidated. The aim of this work was to study the effect of NO on amino acid neurotransmitter release (Asp, Glu, Gly and GABA) in cortical neurons as well as the mechanism underlying the release of these neurotransmitters. Cortical neurons were stimulated with SNAP, a NO donor, and the release of different amino acid neurotransmitters was measured by HPLC. The involvement of voltage dependent Na+ and Ca2+ channels as well as cGMP in its mechanism of action was evaluated. Our results indicate that NO induces release of aspartate, glutamate, glycine and GABA in cortical neurons and that this release is inhibited by ODQ, an inhibitor of soluble guanylate cyclase. Thus, the NO effect on amino acid neurotransmission could be mediated by cGMP formation in cortical neurons. Our data also demonstrate that the Na+ and Ca2+ voltage- dependent calcium channels are involved in the NO effects on cortical neurons.

The nitric oxide donor SNAP-induced amino acid neurotransmitter release in cortical neurons. Effects of blockers of voltage-dependent sodium and calcium channels.

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José Joaquín Merino

Full Text Available The discovery that nitric oxide (NO functions as a signalling molecule in the nervous system has radically changed the concept of neuronal communication. NO induces the release of amino acid neurotransmitters but the underlying mechanisms remain to be elucidated.The aim of this work was to study the effect of NO on amino acid neurotransmitter release (Asp, Glu, Gly and GABA in cortical neurons as well as the mechanism underlying the release of these neurotransmitters. Cortical neurons were stimulated with SNAP, a NO donor, and the release of different amino acid neurotransmitters was measured by HPLC. The involvement of voltage dependent Na+ and Ca2+ channels as well as cGMP in its mechanism of action was evaluated.Our results indicate that NO induces release of aspartate, glutamate, glycine and GABA in cortical neurons and that this release is inhibited by ODQ, an inhibitor of soluble guanylate cyclase. Thus, the NO effect on amino acid neurotransmission could be mediated by cGMP formation in cortical neurons. Our data also demonstrate that the Na+ and Ca2+ voltage- dependent calcium channels are involved in the NO effects on cortical neurons.

Impact on sediments and water by release of copper from chalcopyrite bearing rock due to acidic mine drainage

Science.gov (United States)

Shukla, Anoop Kant; Pradhan, Manoj; Tiwari, Onkar Nath

2018-04-01

Mining activity causes transition of rock-mass from its original position in earth into open environment. The action of environmental elements such air, water, microorganisms leads to oxidation of minerals which constitute the rock. The oxidation of sulphide minerals in presence of moisture releases acidic mine discharge (AMD). The acidic nature of AMD causes leaching of metals from rock minerals. Dissolution of other minerals may occur upon reaction with AMD. Chalcopyrite (CuFeS2) undergoes oxidation in acidic condition releasing copper among other products. This study reveals contamination of copper in sediment samples and seepage water from the tailing dam of a large copper project in located in central India. Elevation was studied using GIS to ascertain to the topographic elevation of tailing dam area. It was located at relatively high altitude causing seepage to flow away from tailing dam. The seepage water from tailing dam was found to be acidic with mean pH value of 4.0 and elevated copper content. Similarly, sediments from seepage water flow displayed elevated copper concentration. The copper concentration in seepage water was found with a mean value of 10.73 mg/l. The sediments from seepage water flow also displayed elevated copper concentration with mean value of 26.92 g/kg. This indicates impact on sediments by release of copper due to acidic mine drainage.

Omega-3 fatty acids and inflammatory processes: from molecules to man.

Science.gov (United States)

Calder, Philip C

2017-10-15

Inappropriate, excessive or uncontrolled inflammation contributes to a range of human diseases. Inflammation involves a multitude of cell types, chemical mediators and interactions. The present article will describe nutritional and metabolic aspects of omega-6 (n-6) and omega-3 (n-3) fatty acids and explain the roles of bioactive members of those fatty acid families in inflammatory processes. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are n-3 fatty acids found in oily fish and fish oil supplements. These fatty acids are capable of partly inhibiting many aspects of inflammation including leucocyte chemotaxis, adhesion molecule expression and leucocyte-endothelial adhesive interactions, production of eicosanoids like prostaglandins and leukotrienes from the n-6 fatty acid arachidonic acid and production of pro-inflammatory cytokines. In addition, EPA gives rise to eicosanoids that often have lower biological potency than those produced from arachidonic acid, and EPA and DHA give rise to anti-inflammatory and inflammation resolving mediators called resolvins, protectins and maresins. Mechanisms underlying the anti-inflammatory actions of EPA and DHA include altered cell membrane phospholipid fatty acid composition, disruption of lipid rafts, inhibition of activation of the pro-inflammatory transcription factor nuclear factor κB so reducing expression of inflammatory genes and activation of the anti-inflammatory transcription factor peroxisome proliferator-activated receptor γ. Animal experiments demonstrate benefit from EPA and DHA in a range of models of inflammatory conditions. Human trials demonstrate benefit of oral n-3 fatty acids in rheumatoid arthritis and in stabilizing advanced atherosclerotic plaques. Intravenous n-3 fatty acids may have benefits in critically ill patients through reduced inflammation. The anti-inflammatory and inflammation resolving actions of EPA, DHA and their derivatives are of clinical relevance. © 2017 The Author

Omega 3 but not omega 6 fatty acids inhibit AP-1 activity and cell transformation in JB6 cells

OpenAIRE

Liu, Guangming; Bibus, Douglas M.; Bode, Ann M.; Ma, Wei-Ya; Holman, Ralph T.; Dong, Zigang

2001-01-01

Epidemiological and animal-based investigations have indicated that the development of skin cancer is in part associated with poor dietary practices. Lipid content and subsequently the derived fatty acid composition of the diet are believed to play a major role in the development of tumorigenesis. Omega 3 (ω3) fatty acids, including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), can effectively reduce the risk of skin cancer whereas omega 6 (ω6) fatty acids such as arachidonic ac...

Wheat bran promotes enrichment within the human colonic microbiota of butyrate-producing bacteria that release ferulic acid.

Science.gov (United States)

Duncan, Sylvia H; Russell, Wendy R; Quartieri, Andrea; Rossi, Maddalena; Parkhill, Julian; Walker, Alan W; Flint, Harry J

2016-07-01

Cereal fibres such as wheat bran are considered to offer human health benefits via their impact on the intestinal microbiota. We show here by 16S rRNA gene-based community analysis that providing amylase-pretreated wheat bran as the sole added energy source to human intestinal microbial communities in anaerobic fermentors leads to the selective and progressive enrichment of a small number of bacterial species. In particular, OTUs corresponding to uncultured Lachnospiraceae (Firmicutes) related to Eubacterium xylanophilum and Butyrivibrio spp. were strongly enriched (by five to 160 fold) over 48 h in four independent experiments performed with different faecal inocula, while nine other Firmicutes OTUs showed > 5-fold enrichment in at least one experiment. Ferulic acid was released from the wheat bran during degradation but was rapidly converted to phenylpropionic acid derivatives via hydrogenation, demethylation and dehydroxylation to give metabolites that are detected in human faecal samples. Pure culture work using bacterial isolates related to the enriched OTUs, including several butyrate-producers, demonstrated that the strains caused substrate weight loss and released ferulic acid, but with limited further conversion. We conclude that breakdown of wheat bran involves specialist primary degraders while the conversion of released ferulic acid is likely to involve a multi-species pathway. © 2015 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

Transcellular lipoxygenase metabolism between monocytes and platelets

Energy Technology Data Exchange (ETDEWEB)

Bigby, T.D.; Meslier, N. (Univ. of California, San Francisco (USA))

1989-09-15

We have examined the effects of co-culture and in vitro co-stimulation on lipoxygenase metabolism in monocytes and platelets. Monocytes were obtained from the peripheral blood of normal volunteers by discontinuous gradient centrifugation and adherence to tissue culture plastic. Platelets were obtained from the platelet-rich plasma of the same donor. When 10(9) platelets and 2.5 x 10(6) monocytes were co-stimulated with 1 microM A23187, these preparations released greater quantities of 12(S)-hydroxy-10-trans-5,8,14-cis-eicosatetraenoic acid, 5(S),12-(S)dihydroxy-6,10-trans-8,14-cis-eicosatetraenoic acid, and leukotriene C4, 5(S)-hydroxy-6(R)-S-glutathionyl-7,9-trans-11,14-cis-eicosatetraenoic (LTC4) when compared with monocytes alone. Release of arachidonic acid, 5-HETE, delta 6-trans-LTB4, and delta 6-trans-12-epi-LTB4 from monocytes was decreased in the presence of platelets. A dose-response curve was constructed and revealed that the above changes became evident when the platelet number exceeded 10(7). Dual radiolabeling experiments with 3H- and 14C-arachidonic acid revealed that monocytes provided arachidonic acid, 5-HETE, and LTA4 for further metabolism by the platelet. Monocytes did not metabolize platelet intermediates detectably. In addition, as much as 1.2 microM 12(S)-hydroxy-10-trans-5,8,14-cis-eicosatetraenoic acid and 12(S)-hydroperoxy-10-trans-5,8,14-cis-eicosatetraenoic acid had no effect on monocyte lipoxygenase metabolism. Platelets were capable of converting LTA4 to LTC4, but conversion of LTA4 to LTB4 was not detected. We conclude that the monocyte and platelet lipoxygenase pathways undergo a transcellular lipoxygenase interaction that differs from the interaction of the neutrophil and platelet lipoxygenase pathways. In this interaction monocytes provide intermediate substrates for further metabolic conversion by platelets in an unidirectional manner.

Acculturation and Plasma Fatty Acid Concentrations in Hispanic and Chinese-American Adults: The Multi-Ethnic Study of Atherosclerosis.

Science.gov (United States)

Diep, Cassandra S; Lemaitre, Rozenn N; Chen, Tzu-An; Baranowski, Tom; Lutsey, Pamela L; Manichaikul, Ani W; Rich, Stephen S; St-Jules, David E; Steffen, Brian T; Tsai, Michael Y; Siscovick, David S; Frazier-Wood, Alexis C

2016-01-01

Acculturation to the U.S. is associated with increased risk of cardiovascular disease, but the etiologic pathways are not fully understood. Plasma fatty acid levels exhibit ethnic differences and are emerging as biomarkers and predictors of cardiovascular disease risk. Thus, plasma fatty acids may represent one pathway underlying the association between acculturation and cardiovascular disease. We investigated the cross-sectional relationship between acculturation and plasma phospholipid fatty acids in a diverse sample of Hispanic- and Chinese-American adults. Participants included 377 Mexican, 320 non-Mexican Hispanic, and 712 Chinese adults from the Multi-Ethnic Study of Atherosclerosis, who had full plasma phospholipid assays and acculturation information. Acculturation was determined from three proxy measures: nativity, language spoken at home, and years in the U.S., with possible scores ranging from 0 (least acculturated) to 5 (most acculturated) points. α-Linolenic acid, linoleic acid, eicosapentaenoic acid, docosahexaenoic acid, and arachidonic acid were measured in fasting plasma. Linear regression models were conducted in race/ethnicity-stratified analyses, with acculturation as the predictor and plasma phospholipid fatty acids as the outcome variables. We ran secondary analyses to examine associations between acculturation and dietary fatty acids for comparison. Covariates included age, gender, education, and income. Contrary to our hypothesis, no statistically significant associations were detected between acculturation and plasma phospholipid fatty acids for Chinese, non-Mexican Hispanic, or Mexican participants. However, acculturation was related to dietary total n-6 fatty acids and dietary n-3/n-6 ratios in expected directions for Mexican, non-Mexican Hispanic, and combined Hispanic participants. In Chinese individuals, acculturation was unexpectedly associated with lower arachidonic acid intake. Absence of associations between acculturation and

Free amino acids exhibit anthozoan "host factor" activity: they induce the release of photosynthate from symbiotic dinoflagellates in vitro.

Science.gov (United States)

Gates, R D; Hoegh-Guldberg, O; McFall-Ngai, M J; Bil, K Y; Muscatine, L

1995-08-01

Reef-building corals and other tropical anthozoans harbor endosymbiotic dinoflagellates. It is now recognized that the dinoflagellates are fundamental to the biology of their hosts, and their carbon and nitrogen metabolisms are linked in important ways. Unlike free living species, growth of symbiotic dinoflagellates is unbalanced and a substantial fraction of the carbon fixed daily by symbiont photosynthesis is released and used by the host for respiration and growth. Release of fixed carbon as low molecular weight compounds by freshly isolated symbiotic dinoflagellates is evoked by a factor (i.e., a chemical agent) present in a homogenate of host tissue. We have identified this "host factor" in the Hawaiian coral Pocillopora damicornis as a set of free amino acids. Synthetic amino acid mixtures, based on the measured free amino acid pools of P. damicornis tissues, not only elicit the selective release of 14C-labeled photosynthetic products from isolated symbiotic dinoflagellates but also enhance total 14CO2 fixation.

In vivo incorporation of labeled fatty acids in rat liver lipids after oral administration

International Nuclear Information System (INIS)

Leyton, J.; Drury, P.J.; Crawford, M.A.

1987-01-01

Striking differences were found in the compartmentalization of fatty acids into liver lipid fractions. The saturated fatty acids--lauric, myristic, palmitic and stearic--were incorporated into phosphoglycerides at faster rates with increasing chain lengths, while triglyceride incorporation was almost uniform. The degree of incorporation of the unsaturated fatty acids into phosphoglycerides (structural) compared to triglyceride (storage and energy) was the converse of their oxidation rates. The incorporation of oleic, linoleic and alpha-linolenic acids was mainly into triglyceride, whereas dihomo-gamma-linolenic acid and arachidonic acid were preferentially incorporated into phosphoglycerides. The data suggest that distribution of each fatty acid is different depending on its destination for structural or energy function

Preparation of magnetic polylactic acid microspheres and investigation of its releasing property for loading curcumin

Energy Technology Data Exchange (ETDEWEB)

Li Fengxia [Heilongjiang Key Laboratory of Molecular Design and Preparation of Flame Retarded Materials, College of Science, Northeast Forestry University, Harbin 150040 (China); Li Xiaoli, E-mail: lixiaoli0903@163.com [Heilongjiang Key Laboratory of Molecular Design and Preparation of Flame Retarded Materials, College of Science, Northeast Forestry University, Harbin 150040 (China); Li Bin, E-mail: libinzh62@163.com [Heilongjiang Key Laboratory of Molecular Design and Preparation of Flame Retarded Materials, College of Science, Northeast Forestry University, Harbin 150040 (China)

2011-11-15

In order to obtain a targeting drug carrier system, magnetic polylactic acid (PLA) microspheres loading curcumin were synthesized by the classical oil-in-water emulsion solvent-evaporation method. In the Fourier transform infrared spectra of microspheres, the present functional groups of PLA were all kept invariably. The morphology and size distribution of magnetic microspheres were observed with scanning electron microscopy and dynamic light scattering, respectively. The results showed that the microspheres were regularly spherical and the surface was smooth with a diameter of 0.55-0.75 {mu}m. Magnetic Fe{sub 3}O{sub 4} was loaded in PLA microspheres and the content of magnetic particles was 12 wt% through thermogravimetric analysis. The magnetic property of prepared microspheres was measured by vibrating sample magnetometer. The results showed that the magnetic microspheres exhibited typical superparamagnetic behavior and the saturated magnetization was 14.38 emu/g. Through analysis of differential scanning calorimetry, the curcumin was in an amorphous state in the magnetic microspheres. The drug loading, encapsulation efficiency and releasing properties of curcumin in vitro were also investigated by ultraviolet-visible spectrum analysis. The results showed that the drug loading and encapsulation efficiency were 8.0% and 24.2%, respectively. And curcumin was obviously slowly released because the cumulative release percentage of magnetic microspheres in the phosphate buffer (pH=7.4) solution was only 49.01% in 72 h, and the basic release of curcumin finished in 120 h. - Highlights: > We prepare magnetic polylactic acid microspheres loading curcumin. > The classical oil-in-water emulsion solvent-evaporation method is used. > The magnetic microspheres are regularly spherical with a diameter of 0.55-0.75 {mu}m. > They show a certain sustained release effect on in vitro drug releasing.

Kinetics of aluminum and sulfate release from forest soil by mono- and diprotic aliphatic acids

Energy Technology Data Exchange (ETDEWEB)

Evans, A. Jr.; Zelazny, L.W. (Virginia Polytechnic Institute and State Univ., Blacksburg (USA))

1990-06-01

A batch equilibration study evaluated the influence of naturally occurring low-molecular-weight mono- and diprotic aliphatic acids on the rate of Al and SO{sub 4}{sup 2{minus}} release in a Cecil soil (Typic Hapludult). The authors adjusted the pH of the organic acids (OAs) and of the soil suspension (3.8% w/w) to pH 4.0 and allowed them to equilibrate thermally before the experiment. After rapid addition of OAs to the soil suspension, they took solution samples at various time intervals and analyzed for Al, SO{sub 4}{sup 2{minus}}, and OA concentration. The initial concentration of OA in suspension was 1 {times} 10{sup {minus}5} mol liter{sup {minus}1}. Both Al and SO{sub 4}{sup 2{minus}} release followed pseudo-first-order kinetics, whereas OA adsorption obeyed simple first-order kinetics. The rate of Al release (k{sub 1}) was more rapid for the diprotic OA treatment (20.4 {times} 10{sup {minus}8} mol s{sup {minus}1}), as was SO{sub 4}{sup 2{minus}} release (1.63 {times} 10{sup {minus}8} mol s{sup {minus}1}), compared to the monoprotic OA treatment. The rate of Al release varied inversely with OA chain length and the distance between -COOH functional groups. The addition of substituent -OH groups between the -COOH groups further reduced K{sub 1}. A similar trend was observed for the rate of SO{sub 4}{sup 2{minus}} release (k{sub 1}) into solution. Monoprotic OAs were more rapidly adsorbed to the particle surfaces than were diprotic OAs. The authors postulate that removal of Al and SO{sub 4}{sup 2{minus}} from solution occurs via selective mineral precipitation.

Preparation of magnetic polylactic acid microspheres and investigation of its releasing property for loading curcumin

International Nuclear Information System (INIS)

Li Fengxia; Li Xiaoli; Li Bin

2011-01-01

In order to obtain a targeting drug carrier system, magnetic polylactic acid (PLA) microspheres loading curcumin were synthesized by the classical oil-in-water emulsion solvent-evaporation method. In the Fourier transform infrared spectra of microspheres, the present functional groups of PLA were all kept invariably. The morphology and size distribution of magnetic microspheres were observed with scanning electron microscopy and dynamic light scattering, respectively. The results showed that the microspheres were regularly spherical and the surface was smooth with a diameter of 0.55-0.75 μm. Magnetic Fe 3 O 4 was loaded in PLA microspheres and the content of magnetic particles was 12 wt% through thermogravimetric analysis. The magnetic property of prepared microspheres was measured by vibrating sample magnetometer. The results showed that the magnetic microspheres exhibited typical superparamagnetic behavior and the saturated magnetization was 14.38 emu/g. Through analysis of differential scanning calorimetry, the curcumin was in an amorphous state in the magnetic microspheres. The drug loading, encapsulation efficiency and releasing properties of curcumin in vitro were also investigated by ultraviolet-visible spectrum analysis. The results showed that the drug loading and encapsulation efficiency were 8.0% and 24.2%, respectively. And curcumin was obviously slowly released because the cumulative release percentage of magnetic microspheres in the phosphate buffer (pH=7.4) solution was only 49.01% in 72 h, and the basic release of curcumin finished in 120 h. - Highlights: → We prepare magnetic polylactic acid microspheres loading curcumin. → The classical oil-in-water emulsion solvent-evaporation method is used. → The magnetic microspheres are regularly spherical with a diameter of 0.55-0.75 μm. → They show a certain sustained release effect on in vitro drug releasing.

Reduction of free fatty acids by acipimox enhances the growth hormone (GH) responses to GH-releasing peptide 2 in elderly men

NARCIS (Netherlands)

Smid, HEC; de Vries, WR; Niesink, M; Bolscher, E; Waasdorp, EJ; Dieguez, C; Casanueva, FF; Koppeschaar, HPF

2000-01-01

GH release is increased by reducing circulating free fatty acids (FFAs). Aging is associated with decreased plasma GH concentrations. We evaluated GH releasing capacity in nine healthy elderly men after administration of GH-releasing peptide 2 (GHRP-2), with or without pretreatment with the

Synthesis and HNO Donating Properties of the Piloty's Acid Analogue Trifluoromethanesulphonylhydroxamic acid: Evidence for Quantitative Release of HNO at Neutral pH Conditions.