90 research outputs found

    Antinociceptive effects of tetrazole inhibitors of endocannabinoid inactivation: Cannabinoid and non-cannabinoid receptor-mediated mechanisms

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    Background and purpose: Tetrazoles were recently developed as inhibitors of the cellular uptake of the endocannabinoid anandamide or of its hydrolysis by fatty acid amide hydrolase (FAAH), but were proposed to act also on non-endocannabinoid-related serine hydrolases. Experimental approach: We tested, in a model of inflammatory pain induced in mice by formalin, five chemically similar inhibitors: (i) OMDM119 and OMDM122, two potent carbamoyl tetrazole FAAH inhibitors with no effect on anandamide uptake; (ii) LY2183240, a carbamoyl tetrazole with activity as both FAAH and uptake inhibitor; (iii) OMDM132, a non-carbamoyl tetrazole with activity only as uptake inhibitor and iv) OMDM133, a non-carbamoyl tetrazole with no activity at either FAAH or uptake. Results: All compounds (2.5-10 mg kg -1, i.p.) inhibited the second phase of the nocifensive response induced by intraplantar injection of formalin. The effects of OMDM119, OMDM122 and OMDM133 were not antagonized by pretreatment with cannabinoid CB 1 receptor antagonists, such as rimonabant or AM251 (1-3 mg kg -1, i.p.). The effects of LY2183240 and OMDM132 were fully or partially antagonized by rimonabant, respectively, and the latter compound was also partly antagonized by the CB 2 receptor antagonist, AM630. Conclusions and implications: (i) non-FAAH hydrolases might be entirely responsible for the antinociceptive activity of some, but not all, tetrazole FAAH inhibitors, (ii) the presence of a carbamoylating group is neither necessary nor sufficient for such compounds to act through targets other than FAAH and (iii) inhibition of anandamide uptake is responsible for part of this antinociceptive activity, independently of effects on FAAH. © 2008 Macmillan Publishers Limited All rights reserved

    A Social Sciences and Humanities research agenda for transport and mobility in Europe: key themes and 100 research questions

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    Transport and mobility systems need to be transformed to meet climate change goals and reduce negative environmental and social effects. Despite EU policies having targeted such problems for more than three decades, transitions have been slow and geographically uneven. For effective change to happen, transport and mobility research needs fresh perspectives and better integration of knowledge from the Social Sciences and Humanities. Based on a Horizon Scanning approach, which allowed for a great deal of openness and variety in scholarly viewpoints, this paper presents a novel research agenda consisting of 8 themes and 100 research questions that may contribute to achieving environmentally sustainable mobility transitions within Europe. This research agenda highlights the need to not only support technological solutions for low-carbon mobility, but the importance of transformative policies that include new processes of knowledge production, civic participation and epistemic justice. We contend that the agenda points to the need for further research on the dynamics of science-society interactions

    Endocannabinoids Generated by Ca2+ or by Metabotropic Glutamate Receptors Appear to Arise from Different Pools of Diacylglycerol Lipase

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    The identity and subcellular sources of endocannabinoids (eCBs) will shape their ability to affect synaptic transmission and, ultimately, behavior. Recent discoveries support the conclusion that 2-arachidonoyl glycerol, 2-AG, is the major signaling eCB, however, some important issues remain open. 2-AG can be synthesized by a mechanism that is strictly Ca2+-dependent, and another that is initiated by G-protein coupled receptors (GPCRs) and facilitated by Ca2+. An important question is whether or not the 2-AG in these cases is synthesized by the same pool of diacylglycerol lipase alpha (DAGLα). Using whole-cell voltage-clamp techniques in CA1 pyramidal cells in acute in vitro rat hippocampal slices, we investigated two mechanistically distinct eCB-mediated responses to address this issue. We now report that pharmacological inhibitors of DGLα have quantitatively different effects on eCB-mediated responses triggered by different stimuli, suggesting that functional, and perhaps physical, distinctions among pools of DAGLα exist

    A Social Sciences and Humanities research agenda for transport and mobility in Europe: key themes and 100 research questions

    Get PDF
    Transport and mobility systems need to be transformed to meet climate change goals and reduce negative environmental and social effects. Despite EU policies having targeted such problems for more than three decades, transitions have been slow and geographically uneven. For effective change to happen, transport and mobility research needs fresh perspectives and better integration of knowledge from the Social Sciences and Humanities. Based on a Horizon Scanning approach, which allowed for a great deal of openness and variety in scholarly viewpoints, this paper presents a novel research agenda consisting of 8 themes and 100 research questions that may contribute to achieving environmentally sustainable mobility transitions within Europe. This research agenda highlights the need to not only support technological solutions for low-carbon mobility, but the importance of transformative policies that include new processes of knowledge production, civic participation and epistemic justice. We contend that the agenda points to the need for further research on the dynamics of science-society interactions

    The effects of an Inhibitor of Diglyceride Lipase on Collagen-induced Pltelet Activation

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    Human platelet activation by collagen occurs in a dose-dependent manner. High concentrations of collagen bind to a pair of receptors, the α2ß1 integrin and GPVI/FcRγ, which stimulate a cascade of events including Syk, LAT, Btk , Gads and phospholipase Cγ2, leading to calcium release and protein kinase C (PKC) activation. Calcium and PKC are responsible for a range of platelet responses including exocytosis and aggregation, as well as the cytosolic phospholipase A2 (cPLA2)-mediated release of arachidonic acid which is converted to thromboxane (Tx) A2. In contrast low concentrations of collagen are acutely aspirin sensitive, and calcium release and aggregation are TxA2–dependent. Under these conditions cPLA2 is not involved and it has been suggested that phospholipase C generates diglyceride (DG) from which arachidonic acid is liberated by diacylglycerol lipase (DGL). Here a novel DGL blocker (OMDM-188), inhibited collagen-, but not arachidonic acid-, induced aggregation and TxA2 synthesis. Furthermore OMDM-188 inhibited collagen-induced arachidonic acid release. Finally OMDM-188 inhibited collagen-induced p38MAPK, but not ERK, phosphorylation, with no effect on the phosphorylation of either enzyme in response to arachidonic acid. Taken together these data suggest a role for a pathway involving PLC liberating DG from membrane phospholipids in response to minimallyactivate concentrations of collagen. The DG serves as a substrate for DGL, potentially under the regulations of p38MAPK, to release arachidonic acid which is subsequently converted to TxA2 which mediates the final platelet response

    Exploring the interest of 1,2-dithiolane ring system in peptide chemistry. Synthesis of a chemotactic tripeptide and X-ray crystal structure of a 4-amino-1,2-dithiolane-4-carboxylic acid derivative.

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    Due to their relevant biological functions and specific chemical reactivity 1,2-dithiolanes (five-membered cyclic disulfides) represent an emerging class of heterocyclic compounds. However, despite the extensive research centered on lipoic acid and its analogues, only very few data are at the present available on peptides containing this ring system. We report here synthesis, conformation and bioactivity of a fMLF-OMe analogue, namely For-Met-Adt-Phe-OMe (7), in which the residue of the 4-amino-1,2-dithiolane-4-carboxylic acid (Adt) (4) replaces the central L-leucine. The crystal conformation of the synthetic intermediate Boc-Adt-OMe (5) is also described and compared to that of lipoic acid (R-1,2-dithiolane-3-pentanoic acid) (3) and asparagusic acid (1,2-dithiolane-4-carboxylic acid) (2)

    Preparative and regiochemical aspects of the palladium-catalyzed carbonylative coupling of 2-hydroxyaryl iodides with ethynylarenes

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    The title reaction has been conveniently carried out in DMF at 60°C unakr 1 atm of CO pressure using DBU as the base and Pd(OAc)z(DPPF)2 as the catalyst to t@ord generally muhtres offlavones 4 and atuones 5 in varying yields, dependtng on the mbstituents in the both reactants. Factors controlling the regioselectivtty for 4 or 5 formation in thts and in sunilar, previotuly reported . coupling procedwes have been examined
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