1
|
Martinez-Perez JA, Iyengar S, Shannon HE, Bleakman D, Alt A, Clawson DK, Arnold BM, Bell MG, Bleisch TJ, Castaño AM, Del Prado M, Dominguez E, Escribano AM, Filla SA, Ho KH, Hudziak KJ, Jones CK, Mateo A, Mathes BM, Mattiuz EL, Ogden AML, Simmons RMA, Stack DR, Stratford RE, Winter MA, Wu Z, Ornstein PL. GluK1 antagonists from 6-(tetrazolyl)phenyl decahydroisoquinoline derivatives: In vitro profile and in vivo analgesic efficacy. Bioorg Med Chem Lett 2013; 23:6463-6. [DOI: 10.1016/j.bmcl.2013.09.045] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 09/13/2013] [Accepted: 09/13/2013] [Indexed: 11/15/2022]
|
2
|
Martinez-Perez JA, Iyengar S, Shannon HE, Bleakman D, Alt A, Arnold BM, Bell MG, Bleisch TJ, Castaño AM, Del Prado M, Dominguez E, Escribano AM, Filla SA, Ho KH, Hudziak KJ, Jones CK, Mateo A, Mathes BM, Mattiuz EL, Ogden AML, Simmons RMA, Stack DR, Stratford RE, Winter MA, Wu Z, Ornstein PL. GluK1 antagonists from 6-(carboxy)phenyl decahydroisoquinoline derivatives. SAR and evaluation of a prodrug strategy for oral efficacy in pain models. Bioorg Med Chem Lett 2013; 23:6459-62. [DOI: 10.1016/j.bmcl.2013.09.046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 09/13/2013] [Accepted: 09/13/2013] [Indexed: 11/25/2022]
|
3
|
Mattes H, Carcache D, Kalkman HO, Koller M. alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) antagonists: from bench to bedside. J Med Chem 2010; 53:5367-82. [PMID: 20356304 DOI: 10.1021/jm901688m] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Henri Mattes
- Novartis Pharma AG, Werk Klybeck, WKL-122-241 Postfach, CH-4002 Basel, Switzerland.
| | | | | | | |
Collapse
|
4
|
Dargan SL, Clarke VRJ, Alushin GM, Sherwood JL, Nisticò R, Bortolotto ZA, Ogden AM, Bleakman D, Doherty AJ, Lodge D, Mayer ML, Fitzjohn SM, Jane DE, Collingridge GL. ACET is a highly potent and specific kainate receptor antagonist: characterisation and effects on hippocampal mossy fibre function. Neuropharmacology 2009; 56:121-30. [PMID: 18789344 PMCID: PMC2637447 DOI: 10.1016/j.neuropharm.2008.08.016] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Revised: 08/04/2008] [Accepted: 08/07/2008] [Indexed: 11/24/2022]
Abstract
Kainate receptors (KARs) are involved in both NMDA receptor-independent long-term potentiation (LTP) and synaptic facilitation at mossy fibre synapses in the CA3 region of the hippocampus. However, the identity of the KAR subtypes involved remains controversial. Here we used a highly potent and selective GluK1 (formerly GluR5) antagonist (ACET) to elucidate roles of GluK1-containing KARs in these synaptic processes. We confirmed that ACET is an extremely potent GluK1 antagonist, with a Kb value of 1.4+/-0.2 nM. In contrast, ACET was ineffective at GluK2 (formerly GluR6) receptors at all concentrations tested (up to 100 microM) and had no effect at GluK3 (formerly GluR7) when tested at 1 microM. The X-ray crystal structure of ACET bound to the ligand binding core of GluK1 was similar to the UBP310-GluK1 complex. In the CA1 region of hippocampal slices, ACET was effective at blocking the depression of both fEPSPs and monosynaptically evoked GABAergic transmission induced by ATPA, a GluK1 selective agonist. In the CA3 region of the hippocampus, ACET blocked the induction of NMDA receptor-independent mossy fibre LTP. To directly investigate the role of pre-synaptic GluK1-containing KARs we combined patch-clamp electrophysiology and 2-photon microscopy to image Ca2+ dynamics in individual giant mossy fibre boutons. ACET consistently reduced short-term facilitation of pre-synaptic calcium transients induced by 5 action potentials evoked at 20-25Hz. Taken together our data provide further evidence for a physiological role of GluK1-containing KARs in synaptic facilitation and LTP induction at mossy fibre-CA3 synapses.
Collapse
Affiliation(s)
- Sheila L Dargan
- MRC Centre for Synaptic Plasticity, University of Bristol, Bristol BS8 1TD, UK.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Kainate receptors: Pharmacology, function and therapeutic potential. Neuropharmacology 2009; 56:90-113. [DOI: 10.1016/j.neuropharm.2008.08.023] [Citation(s) in RCA: 203] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2008] [Revised: 08/04/2008] [Accepted: 08/07/2008] [Indexed: 01/28/2023]
|
6
|
Abstract
Glutamic acid (Glu) is the major excitatory neurotransmitter in the mammalian central nervous system (CNS) where it is involved in the physiological regulation of different processes. It has been well established that excessive endogenous Glu is associated with many acute and chronic neurodegenerative disorders such as cerebral ischaemia, epilepsy, amiotrophic lateral sclerosis, Parkinson's, and Alzheimer's disease. These data have consequently added great impetus to the research in this field. In fact, many Glu receptor antagonists acting at the N-methyl-D-aspartic acid (NMDA), 2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA), and/or kainic acid (KA) receptors have been developed as research tools and potential therapeutic agents. Ligands showing competitive antagonistic action at the AMPA type of Glu receptors were first reported in 1988, and the systemically active 2,3-dihydroxy-6-nitro-7-sulphamoyl-benzo[f]quinoxaline (NBQX) was first shown to have useful therapeutic effects in animal models of neurological disease in 1990. Since then, the quinoxaline template has represented the backbone of various competitive AMPA receptor antagonists belonging to different classes which had been developed in order to increase potency, selectivity and water solubility, but also to prolong the "in vivo" action. Compounds that present better pharmacokinetic properties and less serious adverse effects with respect to the others previously developed are undergoing clinical evaluation. In the near future, the most important clinical application for the AMPA receptor antagonists will probably be as neuroprotectant in neurodegenerative diseases, such as epilepsy, for the treatment of patients not responding to current therapies. The present review reports the history of competitive AMPA receptor antagonists from 1988 up to today, providing a systematic coverage of both the open and patent literature.
Collapse
Affiliation(s)
- Daniela Catarzi
- Dipartimento di Scienze Farmaceutiche, Universita' degli Studi di Firenze, Polo Scientifico, Via U. Schiff, 6-50019 Sesto Fiorentino (Firenze), Italy.
| | | | | |
Collapse
|
7
|
Dominguez E, Iyengar S, Shannon HE, Bleakman D, Alt A, Arnold BM, Bell MG, Bleisch TJ, Buckmaster JL, Castano AM, Del Prado M, Escribano A, Filla SA, Ho KH, Hudziak KJ, Jones CK, Martinez-Perez JA, Mateo A, Mathes BM, Mattiuz EL, Ogden AML, Simmons RMA, Stack DR, Stratford RE, Winter MA, Wu Z, Ornstein PL. Two prodrugs of potent and selective GluR5 kainate receptor antagonists actives in three animal models of pain. J Med Chem 2005; 48:4200-3. [PMID: 15974569 DOI: 10.1021/jm0491952] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Amino acids 5 and 7, two potent and selective competitive GluR5 KA receptor antagonists, exhibited high GluR5 receptor affinity over other glutamate receptors. Their ester prodrugs 6 and 8 were orally active in three models of pain: reversal of formalin-induced paw licking, carrageenan-induced thermal hyperalgesia, and capsaicin-induced mechanical hyperalgesia.
Collapse
Affiliation(s)
- Esteban Dominguez
- Centro de Investigación Lilly, S. A. Avda. De la Industria 30, 28108-Alcobendas, Madrid, Spain.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Kwak BS. Applications of Heterogeneous Catalytic Processes to the Environmentally Friendly Synthesis of Fine Chemicals. CATALYSIS SURVEYS FROM ASIA 2005. [DOI: 10.1007/s10563-005-5996-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
9
|
Palecek J, Neugebauer V, Carlton SM, Iyengar S, Willis WD. The effect of a kainate GluR5 receptor antagonist on responses of spinothalamic tract neurons in a model of peripheral neuropathy in primates. Pain 2004; 111:151-61. [PMID: 15327819 DOI: 10.1016/j.pain.2004.06.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2003] [Revised: 05/21/2004] [Accepted: 06/07/2004] [Indexed: 10/26/2022]
Abstract
The responses of antidromically identified spinothalamic tract (STT) neurons to mechanical and thermal stimuli were compared in anesthetized normal and neuropathic monkeys before and after administration of a GluR5 kainate receptor antagonist (LY382884) into the spinal cord dorsal horn through a microdialysis fiber. Peripheral neuropathy was induced by tight ligation of the L7 spinal nerve 13-15 days prior to the experiment. STT neurons recorded in the animals with neuropathy showed increased responsiveness to weak mechanical stimuli and to heating and cooling of the skin compared to STT cells in normal animals. In both normal and the neuropathic monkeys the responses of the STT neurons to mechanical and thermal stimuli were attenuated by LY382884 application in a concentration-dependent manner. Intraspinal application of LY382884 in the neuropathic animals led to a potent reduction of those responses of the STT neurons that were aggravated by the peripheral neuropathy (weak mechanical, heat and innocuous cooling stimuli). These results suggest that kainate receptors are involved in synaptic activation of STT cells in the normal state and may also play an important role in pathological pain states such as peripheral neuropathy in primates. Kainate receptor antagonists could thus be useful for the treatment of certain forms of allodynia and hyperalgesia.
Collapse
Affiliation(s)
- J Palecek
- Institute of Physiology, Academy of Sciences, Prague, Czech Republic
| | | | | | | | | |
Collapse
|
10
|
Lauri SE, Bortolotto ZA, Nistico R, Bleakman D, Ornstein PL, Lodge D, Isaac JTR, Collingridge GL. A role for Ca2+ stores in kainate receptor-dependent synaptic facilitation and LTP at mossy fiber synapses in the hippocampus. Neuron 2003; 39:327-41. [PMID: 12873388 DOI: 10.1016/s0896-6273(03)00369-6] [Citation(s) in RCA: 158] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Compared with NMDA receptor-dependent LTP, much less is known about the mechanism of induction of NMDA receptor-independent LTP; the most extensively studied form of which is mossy fiber LTP in the hippocampus. In the present study we show that Ca2+-induced Ca2+ release from intracellular stores is involved in the induction of mossy fiber LTP. This release also contributes to the kainate receptor-dependent component of the pronounced synaptic facilitation that occurs during high-frequency stimulation. We also present evidence that the trigger for this Ca2+ release is Ca2+ permeation through kainate receptors. However, these novel synaptic mechanisms can be bypassed when the Ca2+ concentration is raised (from 2 to 4 mM), via a compensatory involvement of L-type Ca2+ channels. These findings suggest that presynaptic kainate receptors at mossy fiber synapses can initiate a cascade involving Ca2+ release from intracellular stores that is important in both short-term and long-term plasticity.
Collapse
Affiliation(s)
- Sari E Lauri
- MRC Centre for Synaptic Plasticity, Department of Anatomy, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, United Kingdom
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Rasmussen K, Vandergriff J. The selective iGluR1-4 (AMPA) antagonist LY300168 attenuates morphine-withdrawal-induced activation of locus coeruleus neurons and behavioural signs of morphine withdrawal. Neuropharmacology 2003; 44:88-92. [PMID: 12559125 DOI: 10.1016/s0028-3908(02)00296-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Previously, we have shown that the AMPA (iGluR1-4) antagonist LY293558 attenuates the morphine-withdrawal-induced activation of locus coeruleus neurons and behavioral signs of morphine withdrawal. However, LY293558 has since been shown to also have affinity for one subtype of kainate receptor (iGluR5). In this study, we examined the effects of a selective antagonist of iGluR1-4 receptors, LY300168 (GYKI 53655), and a selective antagonist of iGluR5 receptors, LY382884, on the morphine-withdrawal-induced activation of locus coeruleus neurons and behavioral signs of morphine withdrawal. In in vivo recordings from anesthetized rats, pretreatment with LY300168 (0.3-3.0 mg/kg, s.c.), but not LY382884 (at a dose known to have central effects; 100 mg/kg, s.c.) attenuated the morphine-withdrawal-induced activation of LC neurons. In unanesthetized, morphine-dependent rats, pretreatment with LY300168 (0.3-3.0 mg/kg, s.c.), but not LY382884 (100 mg/kg, s.c.), suppressed the severity and occurrence of naltrexone-precipitated morphine-withdrawal signs. These results indicate iGluR1-4 (AMPA) receptors, but not iGluR5 receptors, play an important role the morphine-withdrawal-induced activation of LC neurons and a subset of behavioral signs of morphine withdrawal. In addition, selective AMPA antagonists may have therapeutic effects in man for the treatment of withdrawal from opiates and other drugs of abuse.
Collapse
Affiliation(s)
- Kurt Rasmussen
- Neuroscience Research, Lilly Research Laboratories, Eli Lilly & Co., Indianapolis, IN 46285, USA.
| | | |
Collapse
|
12
|
Filla SA, Winter MA, Johnson KW, Bleakman D, Bell MG, Bleisch TJ, Castaño AM, Clemens-Smith A, del Prado M, Dieckman DK, Dominguez E, Escribano A, Ho KH, Hudziak KJ, Katofiasc MA, Martinez-Perez JA, Mateo A, Mathes BM, Mattiuz EL, Ogden AML, Phebus LA, Stack DR, Stratford RE, Ornstein PL. Ethyl (3S,4aR,6S,8aR)-6-(4-ethoxycar- bonylimidazol-1-ylmethyl)decahydroiso-quinoline-3-carboxylic ester: a prodrug of a GluR5 kainate receptor antagonist active in two animal models of acute migraine. J Med Chem 2002; 45:4383-6. [PMID: 12238915 DOI: 10.1021/jm025548q] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Amino diacid 3, a highly selective competitive GluR5 kainate receptor antagonist, exhibited high GluR5 receptor affinity and selectivity over other glutamate receptors. Its diethyl ester prodrug 4 was orally active in two models of migraine: the neurogenic dural plasma protein extravasation model and the nucleus caudalis c-fos expression model. These data suggest that a GluR5 kainate receptor antagonist might be an efficacious antimigraine therapy with a novel mechanism of action.
Collapse
Affiliation(s)
- Sandra A Filla
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, 46285, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Kidd FL, Coumis U, Collingridge GL, Crabtree JW, Isaac JTR. A presynaptic kainate receptor is involved in regulating the dynamic properties of thalamocortical synapses during development. Neuron 2002; 34:635-46. [PMID: 12062046 DOI: 10.1016/s0896-6273(02)00699-2] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Previous studies have shown that pharmacological activation of presynaptic kainate receptors at glutamatergic synapses facilitates or depresses transmission in a dose-dependent manner. However, the only synaptically activated kainate autoreceptor described to date is facilitatory. Here, we describe a kainate autoreceptor that depresses synaptic transmission. This autoreceptor is present at developing thalamocortical synapses in the barrel cortex, specifically regulates transmission at frequencies corresponding to those observed in vivo during whisker activation, and is developmentally down regulated during the first postnatal week. This receptor may, therefore, limit the transfer of high-frequency activity to the developing cortex, the loss of which mechanism may be important for the maturation of sensory processing.
Collapse
Affiliation(s)
- Fleur L Kidd
- MRC Centre for Synaptic Plasticity, Department of Anatomy, University of Bristol, BS8 1TD, United Kingdom
| | | | | | | | | |
Collapse
|
14
|
Lauri SE, Delany C, J Clarke VR, Bortolotto ZA, Ornstein PL, T R Isaac J, Collingridge GL. Synaptic activation of a presynaptic kainate receptor facilitates AMPA receptor-mediated synaptic transmission at hippocampal mossy fibre synapses. Neuropharmacology 2001; 41:907-15. [PMID: 11747895 DOI: 10.1016/s0028-3908(01)00152-6] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The development of GluR5-selective kainate receptor ligands is helping to elucidate the functions of kainate receptors in the CNS. Here we have further characterised the actions of a GluR5 selective agonist, ATPA, and a GluR5 selective antagonist, LY382884, in the CA3 region of rat hippocampal slices. In addition, we have used LY382884 to study a novel synaptic mechanism. This antagonist substantially reduces frequency facilitation of mossy fibre synaptic transmission, monitored as either AMPA or NMDA receptor-mediated EPSCs. This suggests that GluR5-containing kainate receptors on mossy fibres function as autoreceptors to facilitate the synaptic release of L-glutamate, in a frequency-dependent manner.
Collapse
Affiliation(s)
- S E Lauri
- MRC Centre for Synaptic Plasticity, Department of Anatomy, Medical School, University of Bristol, BS8 1TD, Bristol, UK
| | | | | | | | | | | | | |
Collapse
|
15
|
Lauri SE, Bortolotto ZA, Bleakman D, Ornstein PL, Lodge D, Isaac JT, Collingridge GL. A critical role of a facilitatory presynaptic kainate receptor in mossy fiber LTP. Neuron 2001; 32:697-709. [PMID: 11719209 DOI: 10.1016/s0896-6273(01)00511-6] [Citation(s) in RCA: 166] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The mechanisms involved in mossy fiber LTP in the hippocampus are not well established. In the present study, we show that the kainate receptor antagonist LY382884 (10 microM) is selective for presynaptic kainate receptors in the CA3 region of the hippocampus. At a concentration at which it blocks mossy fiber LTP, LY382884 selectively blocks the synaptic activation of a presynaptic kainate receptor that facilitates AMPA receptor-mediated synaptic transmission. Following the induction of mossy fiber LTP, there is a complete loss of the presynaptic kainate receptor-mediated facilitation of synaptic transmission. These results identify a central role for the presynaptic kainate receptor in the induction of mossy fiber LTP. In addition, these results suggest that the pathway by which kainate receptors facilitate glutamate release is utilized for the expression of mossy fiber LTP.
Collapse
Affiliation(s)
- S E Lauri
- MRC Centre for Synaptic Plasticity, Department of Anatomy, Medical School, University of Bristol, Bristol BS8 1TD, United Kingdom
| | | | | | | | | | | | | |
Collapse
|
16
|
Erratum: correction: Kainate receptors are involved in synaptic plasticity. Nature 2001. [DOI: 10.1038/35054109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
17
|
Stanfa LC, Dickenson AH. The role of non-N-methyl-D-aspartate ionotropic glutamate receptors in the spinal transmission of nociception in normal animals and animals with carrageenan inflammation. Neuroscience 1999; 93:1391-8. [PMID: 10501464 DOI: 10.1016/s0306-4522(99)00310-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The role of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) and kainate receptors in spinal nociceptive transmission in both normal animals and animals with carrageenan inflammation was investigated using the AMPA/kainate receptor antagonist 6-nitro-7-sulphamoylbenzo(f)quinoxaline-2,3-dione (NBQX) and the selective GluR5 kainate receptor antagonist LY382884 [3S,4aR,6S,8aR-6-(4-carboxyphenyl)methyl-1,2,3,4,4a,5,6,7,8, 8a-deca-hydroisoquinoline-3-carboxylic acid]. In normal animals, spinal administration of 100 microg of LY382884 produced a significant inhibition of both the C-fibre-evoked response and post-discharge of dorsal horn neurons, with the wind-up of the neurons being reduced by both 50 and 100 microg of LY382884. The spinal actions of LY382884 were enhanced following 3 h of carrageenan inflammation, such that doses of 20 microg and above were able to produce significant inhibitions of the noxious-evoked response of the neurons. Spinal administration of NBQX in normal animals (5-50 microg) inhibited the C-fibre-evoked response of the dorsal horn neurons, but only 50 microg of NBQX was able to inhibit the wind-up and post-discharge of the neurons. Following 3 h of carrageenan inflammation, the ability of NBQX to inhibit the wind-up and post-discharge of the neurons was markedly enhanced. These data suggest that both AMPA and kainate GluR5 receptors play an enhanced role in spinal nociceptive processing following the development of peripheral inflammation, as antagonists at both receptors are more effective against nociceptive responses, including wind-up under these inflammatory conditions.
Collapse
Affiliation(s)
- L C Stanfa
- Department of Pharmacology, University College London, UK.
| | | |
Collapse
|
18
|
Kotoris CC, Chen MJ, Taylor SD. Preparation of Benzylic α,α-Difluoronitriles, -tetrazoles, and -sulfonates via Electrophilic Fluorination. J Org Chem 1998. [DOI: 10.1021/jo981163x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Christopher C. Kotoris
- Department of Chemistry, University of Toronto, Mississauga Campus, 3359 Mississauga Road North, Mississauga, Ontario, Canada L5L 1C6
| | - Mei-Jin Chen
- Department of Chemistry, University of Toronto, Mississauga Campus, 3359 Mississauga Road North, Mississauga, Ontario, Canada L5L 1C6
| | - Scott D. Taylor
- Department of Chemistry, University of Toronto, Mississauga Campus, 3359 Mississauga Road North, Mississauga, Ontario, Canada L5L 1C6
| |
Collapse
|
19
|
O'Neill MJ, Bond A, Ornstein PL, Ward MA, Hicks CA, Hoo K, Bleakman D, Lodge D. Decahydroisoquinolines: novel competitive AMPA/kainate antagonists with neuroprotective effects in global cerebral ischaemia. Neuropharmacology 1998; 37:1211-22. [PMID: 9849659 DOI: 10.1016/s0028-3908(98)00134-8] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In the present studies, we have evaluated the activity of a series of glutamate receptor antagonists from the decahydroisoquinoline group of compounds both in vitro and in vivo. Compound activity at alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) and kainate receptors was assessed using ligand binding to cloned iGluR2 and iGluR5 receptors and on responses evoked by AMPA and N-methyl-D-aspartate (NMDA) in the cortical wedge preparation. In vivo, compounds were examined for antagonist activity electrophysiologically in the rat spinal cord preparation and in the gerbil model of global cerebral ischaemia. Compounds tested were LY293558, which has been shown to protect in models of focal cerebral ischaemia, LY202157 (an NMDA antagonist), LY246492 (an NMDA and AMPA receptor antagonist), LY302679, LY292025, LY307190, LY280263, LY289178, LY289525, LY294486 (AMPA/kainate antagonists) and LY382884 (an iGluR5 selective antagonist). Results obtained support a role for AMPA receptors in cerebral ischemia. LY377770 (a mixed AMPA/iGluR5 antagonist and active isomer of LY294486) demonstrated good neuroprotection with a 2-h time window and may therefore be useful in the treatment of ischaemic conditions.
Collapse
Affiliation(s)
- M J O'Neill
- Lilly Research Centre, Eli Lilly and Co. Ltd., Windlesham, UK.
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Simmons RM, Li DL, Hoo KH, Deverill M, Ornstein PL, Iyengar S. Kainate GluR5 receptor subtype mediates the nociceptive response to formalin in the rat. Neuropharmacology 1998; 37:25-36. [PMID: 9680256 DOI: 10.1016/s0028-3908(97)00188-3] [Citation(s) in RCA: 142] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In order to study the roles of the AMPA and kainate subtypes of non-NMDA glutamate receptors in the processing of persistent nociceptive information, compounds with varying activities at these receptors were examined for effects on the formalin-induced paw-licking behavior in rats. The selective AMPA antagonist, LY300164 and the mixed AMPA/kainate antagonist, NBQX, were compared for their effects on formalin-induced pain behavior. NBQX (3, 10, 20 mg/kg, i.p.), caused antinociception as well as ataxia whereas the selective AMPA antagonist, LY300164 (3,5,10 mg/kg, i.p.), did not cause antinociception at doses that did not produce ataxia. In view of the well documented distribution of kainate receptors on C fibres and of the kainate-preferring iGluR5 subtype on dorsal root ganglia (DRG), we tested a series of three decahydroisoquinolines with different profiles of activity between iGluR5 and AMPA receptors and all without activity on iGluR6, iGluR7 or KA2 subtypes. LY293558 (0.1, 1, 3, 5 mg/kg, i.p.), which had low micromolar affinity for both iGluR5 and 2 caused, like NBQX, both antinociceptive and ataxic effects. However, the selective iGluR5 antagonist LY382884 (5, 10, 30, 100 mg/kg, i.p.), exhibited antinociceptive actions without ataxia while the iGluR2 preferring antagonist LY302679 (5 mg/kg, i.p), caused ataxia but did not produce antinociceptive effects at that dose. These actions were stereoselective since the enantiomeric compounds, LY293559 and LY302680, were ineffective in these tests. The data strongly suggest an involvement of iGluR5 in the processing of nociceptive information.
Collapse
Affiliation(s)
- R M Simmons
- Lilly Research Laboratories, Eli Lilly, Lilly Corporate Center, Indianapolis, IN 46285, USA
| | | | | | | | | | | |
Collapse
|
21
|
|