51
|
Evans AK, Lowry CA. Pharmacology of the beta-carboline FG-7,142, a partial inverse agonist at the benzodiazepine allosteric site of the GABA A receptor: neurochemical, neurophysiological, and behavioral effects. CNS DRUG REVIEWS 2008; 13:475-501. [PMID: 18078430 DOI: 10.1111/j.1527-3458.2007.00025.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Given the well-established role of benzodiazepines in treating anxiety disorders, beta-carbolines, spanning a spectrum from full agonists to full inverse agonists at the benzodiazepine allosteric site for the GABA(A) receptor, can provide valuable insight into the neural mechanisms underlying anxiety-related physiology and behavior. FG-7,142 is a partial inverse agonist at the benzodiazepine allosteric site with its highest affinity for the alpha1 subunit-containing GABA(A) receptor, although it is not selective. FG-7,142 also has its highest efficacy for modulation of GABA-induced chloride flux mediated at the alpha1 subunit-containing GABA(A) receptor. FG-7,142 activates a recognized anxiety-related neural network and interacts with serotonergic, dopaminergic, cholinergic, and noradrenergic modulatory systems within that network. FG-7,142 has been shown to induce anxiety-related behavioral and physiological responses in a variety of experimental paradigms across numerous mammalian and non-mammalian species, including humans. FG-7,142 has proconflict actions across anxiety-related behavioral paradigms, modulates attentional processes, and increases cardioacceleratory sympathetic reactivity and neuroendocrine reactivity. Both acute and chronic FG-7,142 treatment are proconvulsive, upregulate cortical adrenoreceptors, decrease subsequent actions of GABA and beta-carboline agonists, and increase the effectiveness of subsequent GABA(A) receptor antagonists and beta-carboline inverse agonists. FG-7,142, as a partial inverse agonist, can help to elucidate individual components of full agonism of benzodiazepine binding sites and may serve to identify the specific GABA(A) receptor subtypes involved in specific behavioral and physiological responses.
Collapse
Affiliation(s)
- Andrew K Evans
- University of Bristol, Henry Wellcome Laboratories of Integrative Neuroscience and Endocrinology, Bristol, UK.
| | | |
Collapse
|
52
|
Patankar JA, Khombare RT, Khanwelkar RR, Shet JB. Novel heterocyclic compounds from 2-carboxy-6-methoxybenzofuran-3-acetic acid anhydride. JOURNAL OF CHEMICAL RESEARCH 2008. [DOI: 10.3184/030823408x303231] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
2-Carboxy-6-methoxybenzofuran-3-acetic acid anhydride is utilised for the synthesis of novel polycyclic heteroaromatic compounds in which the benzofuran ring is fused or bound to pyrido[1,4]benzothiazine, thiazole, pyridine, pyrazolo-pyridine, pyrazole, pyrano-pyridine, and pyrazolo[1,5-a]pyrido[3,2-e]pyrimidines using versatile reaction strategies.
Collapse
Affiliation(s)
- Jyoti A. Patankar
- Department of Chemistry, The Institute of Science, 15, Madam Cama Road, Mumbai 400 032, India
| | - Rajiv T. Khombare
- Department of Chemistry, The Institute of Science, 15, Madam Cama Road, Mumbai 400 032, India
| | - Rahul R. Khanwelkar
- Department of Chemistry, The Institute of Science, 15, Madam Cama Road, Mumbai 400 032, India
| | - Jyoti B. Shet
- Department of Chemistry, The Institute of Science, 15, Madam Cama Road, Mumbai 400 032, India
| |
Collapse
|
53
|
Klingensmith LM, Bio MM, Moniz GA. Selective protodeboronation: synthesis of 4-methyl-2-thiopheneboronic anhydride and demonstration of its utility in Suzuki–Miyaura reactions. Tetrahedron Lett 2007. [DOI: 10.1016/j.tetlet.2007.09.060] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
54
|
Becerril J, Hamilton AD. Helix mimetics as inhibitors of the interaction of the estrogen receptor with coactivator peptides. Angew Chem Int Ed Engl 2007; 46:4471-3. [PMID: 17487924 DOI: 10.1002/anie.200700657] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jorge Becerril
- Department of Chemistry, Yale University, P. O. Box 208107, New Haven, CT 06520-8107, USA
| | | |
Collapse
|
55
|
Tu S, Zhu X, Shi F, Zhang J, Zhang Y. An efficient microwave-assisted synthesis of 3,5-unsubstituted 4-substituted-6-aryl-3,4-dihydropyridin-2(1H)-ones derivatives. J Heterocycl Chem 2007. [DOI: 10.1002/jhet.5570440414] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
56
|
Becerril J, Hamilton A. Helix Mimetics as Inhibitors of the Interaction of the Estrogen Receptor with Coactivator Peptides. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200700657] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|
57
|
Möhler H. Molecular regulation of cognitive functions and developmental plasticity: impact of GABAA receptors. J Neurochem 2007; 102:1-12. [PMID: 17394533 DOI: 10.1111/j.1471-4159.2007.04454.x] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
By controlling spike timing and sculpting neuronal rhythms, inhibitory interneurons play a key role in regulating neuronal circuits and behavior. The pronounced diversity of GABAergic (gamma-aminobutyric acid) interneurons is paralleled by an extensive diversity of GABAA receptor subtypes. The region- and domain-specific location of these receptor subtypes offers the opportunity to gain functional insights into the role of defined neuronal circuits. These developments are reviewed with regard to the regulation of sleep, anxiety, memory, sensorimotor processing and post-natal developmental plasticity.
Collapse
Affiliation(s)
- Hanns Möhler
- Institute of Pharmacology, University of Zurich, Zurich, Switzerland.
| |
Collapse
|
58
|
Morris HV, Dawson GR, Reynolds DS, Atack JR, Stephens DN. Both alpha2 and alpha3 GABAA receptor subtypes mediate the anxiolytic properties of benzodiazepine site ligands in the conditioned emotional response paradigm. Eur J Neurosci 2006; 23:2495-504. [PMID: 16706856 DOI: 10.1111/j.1460-9568.2006.04775.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mice with point-mutated alpha2 GABAA receptor subunits (rendering them diazepam insensitive) are resistant to the anxiolytic-like effects of benzodiazepines (BZs) in unconditioned models of anxiety. We investigated the role of the alpha2 GABAA subtype in a model of conditioned anxiety. alpha2(H101R) and wildtype mice were trained in a conditioned emotional response (CER) task, in which lever-pressing for food on a variable interval (VI) schedule was suppressed during the presentation of a conditioned stimulus (CS+) that predicted footshock. The ability of diazepam, ethanol and pentobarbital to reduce suppression during the CS+ was interpreted as an anxiolytic response. Diazepam (0, 0.5, 1, 2, 4 and 8 mg/kg) induced a dose-dependent anxiolytic-like effect in wildtype mice. At high doses, diazepam (2, 4 and 8 mg/kg) was sedative in alpha2(H101R) mice. Analysis of the anxiolytic properties of nonsedative diazepam doses (0.5 and 1 mg/kg), showed that alpha2(H101R) mice were resistant to the anxiolytic effects of diazepam. Equivalent anxiolytic properties of pentobarbital (20 mg/kg) and ethanol (1 and 2 g/kg) were seen in both genotypes. These findings confirm the critical importance of the alpha2 GABAA subtype in mediating BZ anxiolysis. However, as a compound, L-838417, with agonist properties at alpha2, alpha3 and alpha5-containing receptors, gave rise to anxiolytic-like activity in alpha2(H101R) mice in the CER test, alpha3-containing GABA receptors are also likely to contribute to anxiolysis. Observations that alpha2(H101R) mice were more active, and displayed a greater suppression of lever pressing in response to fear-conditioned stimuli than wildtype mice, suggests that the alpha2(H101R) mutation may not be behaviourally silent.
Collapse
Affiliation(s)
- H V Morris
- Department of Psychology, University of Sussex, Falmer, Brighton, BN1 9QG, UK
| | | | | | | | | |
Collapse
|
59
|
Möhler H. GABA(A) receptor diversity and pharmacology. Cell Tissue Res 2006; 326:505-16. [PMID: 16937111 DOI: 10.1007/s00441-006-0284-3] [Citation(s) in RCA: 262] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2006] [Accepted: 06/13/2006] [Indexed: 12/22/2022]
Abstract
Because of its control of spike-timing and oscillatory network activity, gamma-aminobutyric acid (GABA)-ergic inhibition is a key element in the central regulation of somatic and mental functions. The recognition of GABA(A) receptor diversity has provided molecular tags for the analysis of distinct neuronal networks in the control of specific pharmacological and physiological brain functions. Neurons expressing alpha(1)GABA(A) receptors have been found to mediate sedation, whereas those expressing alpha(2)GABA(A) receptors mediate anxiolysis. Furthermore, associative temporal and spatial memory can be regulated by modulating the activity of hippocampal pyramidal cells via extrasynaptic alpha(5)GABA(A) receptors. In addition, neurons expressing alpha(3)GABA(A) receptors are instrumental in the processing of sensory motor information related to a schizophrenia endophenotype. Finally, during the postnatal development of the brain, the maturation of GABAergic interneurons seems to provide the trigger for the experience-dependent plasticity of neurons in the visual cortex, with alpha(1)GABA(A) receptors setting the time of onset of a critical period of plasticity. Thus, particular neuronal networks defined by respective GABA(A) receptor subtypes can now be linked to the regulation of various clearly defined behavioural patterns. These achievements are of obvious relevance for the pharmacotherapy of certain brain disorders, in particular sleep dysfunctions, anxiety disorders, schizophrenia and diseases associated with memory deficits.
Collapse
Affiliation(s)
- H Möhler
- Institute of Pharmacology and Department of Chemistry and Applied Biosciences, University and ETH Zurich, Winterthurerstrasse 190, Zürich, CH-8057, Switzerland.
| |
Collapse
|
60
|
Sabat M, Vanrens JC, Brugel TA, Maier J, Laufersweiler MJ, Golebiowski A, De B, Easwaran V, Hsieh LC, Rosegen J, Berberich S, Suchanek E, Janusz MJ. The development of novel 1,2-dihydro-pyrimido[4,5-c]pyridazine based inhibitors of lymphocyte specific kinase (Lck). Bioorg Med Chem Lett 2006; 16:4257-61. [PMID: 16757169 DOI: 10.1016/j.bmcl.2006.05.072] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Revised: 05/21/2006] [Accepted: 05/22/2006] [Indexed: 11/21/2022]
Abstract
This communication details the synthesis, biological activity, and proposed binding mode of a novel class of tri-cyclic derivatives of 1,2-dihydro-pyrimido[4,5-c]pyridazines 1 and 2. The most potent analogs disclosed showed low nanomolar activity for the inhibition of Lck kinase.
Collapse
Affiliation(s)
- Mark Sabat
- Procter and Gamble Pharmaceuticals, Health Care Research Center, Mason, OH 45040, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
61
|
Carling RW, Russell MGN, Moore KW, Mitchinson A, Guiblin A, Smith A, Wafford KA, Marshall G, Atack JR, Street LJ. 2,3,7-Trisubstituted pyrazolo[1,5-d][1,2,4]triazines: Functionally selective GABAA α3-subtype agonists. Bioorg Med Chem Lett 2006; 16:3550-4. [PMID: 16621541 DOI: 10.1016/j.bmcl.2006.03.081] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2006] [Revised: 03/23/2006] [Accepted: 03/24/2006] [Indexed: 10/24/2022]
Abstract
Novel synthetic routes have been devised for the preparation of previously inaccessible 2,3,7-trisubstituted pyrazolo[1,5-d][1,2,4]triazines 2. These compounds are high affinity ligands for the GABA(A) benzodiazepine binding site and some analogues show functional selectivity for agonism at alpha3-containing receptors over alpha1-containing receptors with the lead compound being 32.
Collapse
Affiliation(s)
- Robert W Carling
- Merck Sharp and Dohme Research Laboratories, The Neuroscience Research Centre, Terlings Park, Harlow, Essex, CM20 2QR, UK.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
62
|
Atack JR. The benzodiazepine binding site of GABA(A) receptors as a target for the development of novel anxiolytics. Expert Opin Investig Drugs 2006; 14:601-18. [PMID: 15926867 DOI: 10.1517/13543784.14.5.601] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Non-selective benzodiazepine (BZ) binding-site full agonists, exemplified by diazepam, act by enhancing the inhibitory effects of GABA at GABA(A) receptors containing either an alpha1, -2, -3 or -5 subunit. However, despite their proven clinical anxiolytic efficacy, such compounds possess a relatively narrow window between doses that produce anxiolysis and those that cause sedation, and are also associated with physical dependence and a potential for abuse. In the late 1980s and early 1990s a number of non-selective partial agonists, exemplified by bretazenil, pazinaclone and abecarnil, were described. Their reduced intrinsic efficacy relative to full agonists such as diazepam resulted in an improved preclinical pharmacological profile in that there was a large window between anxiolytic and sedative doses and their dependence and abuse liabilities were much lower. Unfortunately, these compounds failed, for a variety of reasons, to translate into clinical benefit, and as the public perception of BZs deteriorated interest in the area waned. However, the advent of molecular genetic and pharmacological approaches has begun to delineate which GABA(A) receptor subtypes are associated with the various pharmacological effects of the non-selective BZs. More specifically, the alpha2- and/or alpha3-containing GABA(A) receptors play a role in anxiety whereas the alpha1 subtype is involved in sedation, raising the possibility of a compound that selectively modulates alpha2- and/or alpha3-containing receptors but does not affect alpha1-containing receptors would be a non-sedating anxiolytic. In order to achieve selectivity for the alpha2/alpha3 subtypes relative to alpha1, two approaches may be used; selective affinity or selective efficacy. Selective affinity relies on a compound binding with higher affinity to the alpha2/alpha3 compared with alpha1 subtypes, but to date no such compounds have been described. On the other hand, subtype-selective efficacy relies on a compound binding to all subtypes but having different efficacies at various subtypes (relative selective efficacy, for example SL654198 or pagoclone) or having efficacy at some subtypes but none at others (absolute selective efficacy; for example, L-838417). The status of these and other BZ site compounds with claimed, but often not explicitly stated, GABA(A) subtype selectivity (such as ELB-139 and ocinaplon) will be reviewed in relation to their development as non-sedating anxiolytics for the treatment of generalised anxiety disorder.
Collapse
Affiliation(s)
- John R Atack
- Merck Sharp & Dohme Research Laboratories, Neuroscience Research Centre, Terlings Park, Eastwick Road, Harlow, Essex CM20 2QR, UK.
| |
Collapse
|
63
|
Shen HC, Ding FX, Colletti SL. α-Heteroarylation of Esters, Lactones, Amides, and Lactams by Nucleophilic Aromatic Substitution. Org Lett 2006; 8:1447-50. [PMID: 16562913 DOI: 10.1021/ol060246u] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction: see text] A mild and efficient alpha-heteroarylation of simple esters and amides was developed via nucleophilic aromatic substitution. The choice of NaHMDS in toluene gave the best results. A tandem alpha-heteroarylation and hydroxylation protocol using air as the oxidant afforded tertiary alcohols in good yields.
Collapse
Affiliation(s)
- Hong C Shen
- Department of Medicinal Chemistry, Merck Research Laboratories, Merck & Company, Inc., P.O. Box 2000, Rahway, New Jersey 07065-0900, USA.
| | | | | |
Collapse
|
64
|
L. Pinder J, J. Durrant S, Charrier JD, Jimenez JM, Brenchley G, N. Collier P, Kay D, Miller A, Pierard F, Ramaya S, Sadiq S, C. Twin H. Synthesis of a Stable Pyridyl Boronate and Its Reaction with Aryl and Heteroaryl Halides. HETEROCYCLES 2006. [DOI: 10.3987/com-06-s(w)54] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
65
|
Sieghart W. Structure, pharmacology, and function of GABAA receptor subtypes. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2006; 54:231-63. [PMID: 17175817 DOI: 10.1016/s1054-3589(06)54010-4] [Citation(s) in RCA: 224] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Werner Sieghart
- Division of Biochemistry and Molecular Biology, Center for Brain Research, and Section of Biochemical Psychiatry, University Clinic for Psychiatry, Medical University Vienna, Austria
| |
Collapse
|
66
|
Structural Features of the Binding Site for Diphenin and other Anticonvulsants belonging to the Group of Sodium Channel Blockers. Pharm Chem J 2005. [DOI: 10.1007/s11094-006-0007-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
67
|
Atack JR, Hutson PH, Collinson N, Marshall G, Bentley G, Moyes C, Cook SM, Collins I, Wafford K, McKernan RM, Dawson GR. Anxiogenic properties of an inverse agonist selective for alpha3 subunit-containing GABA A receptors. Br J Pharmacol 2005; 144:357-66. [PMID: 15655523 PMCID: PMC1576012 DOI: 10.1038/sj.bjp.0706056] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Alpha3IA (6-(4-pyridyl)-5-(4-methoxyphenyl)-3-carbomethoxy-1-methyl-1H-pyridin-2-one) is a pyridone with higher binding and functional affinity and greater inverse agonist efficacy for GABA(A) receptors containing an alpha3 rather than an alpha1, alpha2 or alpha5 subunit. If doses are selected that minimise the occupancy at these latter subtypes, then the in vivo effects of alpha3IA are most probably mediated by the alpha3 subtype. Alpha3IA has good CNS penetration in rats and mice as measured using a [(3)H]Ro 15-1788 in vivo binding assay. At doses in rats that produce relatively low levels of occupancy (12%) in the cerebellum (i.e. alpha1-containing receptors), alpha3IA (30 mg kg(-1) i.p.), like the nonselective partial inverse agonist N-methyl-beta-carboline-3-carboxamide (FG 7142), not only caused behavioural disruption in an operant, chain-pulling assay but was also anxiogenic in the elevated plus maze, an anxiogenic-like effect that could be blocked with the benzodiazepine antagonist Ro 15-1788 (flumazenil). Neurochemically, alpha3IA (30 mg kg(-1) i.p.) as well as FG 7142 (15 mg kg(-1) i.p.) increased the concentration of the dopamine metabolite 3,4-dihydroxyphenylacetic acid in rat medial prefrontal cortex by 74 and 68%, respectively, relative to vehicle-treated animals, a response that mimicked that seen following immobilisation stress. Taken together, these data demonstrate that an inverse agonist selective for GABA(A) receptors containing an alpha3 subunit is anxiogenic, and suggest that since alpha3-containing GABA(A) receptors play a role in anxiety, then agonists selective for this subtype should be anxiolytic.
Collapse
Affiliation(s)
- John R Atack
- Merck Sharp & Dohme Research Laboratories, Neuroscience Research Centre, Terlings Park, Eastwick Road, Harlow, Essex CM20 2QR, UK.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
68
|
Licata SC, Platt DM, Cook JM, Sarma PVVS, Griebel G, Rowlett JK. Contribution of GABAAReceptor Subtypes to the Anxiolytic-Like, Motor, and Discriminative Stimulus Effects of Benzodiazepines: Studies with the Functionally Selective Ligand SL651498 [6-Fluoro-9-methyl-2-phenyl-4-(pyrrolidin-1-yl-carbonyl)-2,9-dihydro-1H-pyridol[3,4-b]indol-1-one]. J Pharmacol Exp Ther 2005; 313:1118-25. [PMID: 15687371 DOI: 10.1124/jpet.104.081612] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Benzodiazepines (BZs) are prescribed for a variety of disorders, including those involving anxiety and sleep, but have unwanted side effects that limit their use. Elucidating the GABA(A) receptor mechanisms underlying the behavioral effects of BZs will help develop new drugs having both maximum clinical benefit and minimum adverse side effects. A recently developed compound is SL651498 [6-fluoro-9-methyl-2-phenyl-4-(pyrrolidin-1-yl-carbonyl)-2,9-dihydro-1H-pyridol[3,4-b]indol-1-one], which is a full agonist at GABA(A) receptors containing alpha(2)and alpha(3) subunits and a partial agonist at GABA(A) receptors containing alpha(1) and alpha(5) subunits. We assessed the ability of SL651498 to engender anxiolytic-like, motor, and subjective effects characteristic of BZ-type drugs in nonhuman primates. Anxiolytic-like activity was assessed with a conflict procedure in rhesus monkeys. Motor effects were evaluated in squirrel monkeys using observational techniques, and the subjective effects of SL651498 were assessed in squirrel monkeys trained to discriminate the nonselective BZ triazolam from saline. SL651498 engendered anxiolytic-like effects similar to conventional BZs. In addition, SL651498 fully induced muscle relaxation, but unlike conventional BZs, engendered minimal ataxia. In drug discrimination studies, SL651498 partially substituted for triazolam. This effect was blocked with the alpha(1) GABA(A) subtype-preferring antagonist beta-CCT (beta-carboline-3-carboxylate-t-butyl ester), implicating alpha(1) GABA(A) effects receptors in the subjective of SL651498. Together, these studies suggest that compounds such as SL651498 that have high intrinsic efficacy at alpha(2)GABA(A) and/or alpha(3)GABA(A) receptors may have clinical potential as anxiolytics and muscle relaxants. Moreover, a compound with reduced efficacy at alpha(1) GABA(A) and/or alpha(5) GABA(A) receptors may lack some of the motor and subjective effects associated with conventional BZs.
Collapse
Affiliation(s)
- Stephanie C Licata
- Harvard Medical School, New England Primate Research Center, Southborough, MA 01772, USA.
| | | | | | | | | | | |
Collapse
|
69
|
Said MM, Ahmed AAE, El-Alfy AT. Synthesis and pharmacological screening for muscle relaxant, anticonvulsant, and sedative activities of certain Organic compounds produced by Michael addition. Arch Pharm Res 2004; 27:1194-201. [PMID: 15646790 DOI: 10.1007/bf02975880] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Michael addition of certain nucleophiles on alpha, beta-unsaturated ketones 1 led to the formation of adducts 2-7 as well as the reaction of arylidene derivatives with secondary amines afforded the amino compounds 9 and 11. Also, dialkylmalonates were treated with alpha-cyano cinnamide to afford 13. On the other hand, double Michael cycloaddition of ethylcyanoacetate or tetrachlorophthalic anhydride to the suitable divinylketone were synthesized to produce 15-17. Selected compounds (13 and 6) were screened for muscle relaxant, anticonvulsant, and sedative activities using established pharmacological models. Their activities were compared with that of phenobarbital sodium taken as standard. Compound 6 was the most potent muscle relaxant while compounds 13a and 13c offered the highest anticonvulsant activity. Meanwhile compound 13c showed the highest potentiation of phenobarbital induced sleep in mice.
Collapse
Affiliation(s)
- Makarem M Said
- Organic chemistry Department, Faculty of Pharmacy, Cairo University, Egypt.
| | | | | |
Collapse
|
70
|
|
71
|
Basile AS, Lippa AS, Skolnick P. Anxioselective anxiolytics: can less be more? Eur J Pharmacol 2004; 500:441-51. [PMID: 15464051 DOI: 10.1016/j.ejphar.2004.07.043] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2004] [Indexed: 10/26/2022]
Abstract
Benzodiazepines remain widely used for the treatment of anxiety disorders despite a side-effect profile that includes sedation, myorelaxation, amnesia, and ataxia, and the potential for abuse. gamma-Aminobutyric acid(A) (GABA(A)) receptor partial agonists, subtype-selective agents, and compounds combining both of these features are being developed in an attempt to achieve benzodiazepine-like efficacy without these potentially limiting side effects. This article reviews the nonclinical and clinical studies of "anxioselective" anxiolytics that target GABA(A) receptors and discusses potential mechanisms subserving an anxioselective profile.
Collapse
Affiliation(s)
- Anthony S Basile
- DOV Pharmaceutical, Inc., 433 Hackensack Avenue, Hackensack, NJ 07601, USA.
| | | | | |
Collapse
|
72
|
Möhler H, Fritschy JM, Crestani F, Hensch T, Rudolph U. Specific GABAA circuits in brain development and therapy. Biochem Pharmacol 2004; 68:1685-90. [PMID: 15451412 DOI: 10.1016/j.bcp.2004.07.025] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2004] [Accepted: 07/15/2004] [Indexed: 11/26/2022]
Abstract
GABAergic interneurons are highly diverse and operate with a corresponding diversity of GABA(A) receptor subtypes in controlling behaviour. In this article, we review the significance of GABA(A) receptor heterogeneity for neural circuit development and central nervous system pharmacology. GABA(A) receptor subtypes were identified as selective targets for behavioural actions of benzodiazepines and of selected intravenous anesthetic agents using point mutations which render a specific receptor subtype insensitive to the action of the respective drugs and also by novel subtype-selective ligands. The pharmacological separation of anxiolysis and sedation guides the development of novel anxiolytics, while inverse agonism at extrasynaptic GABA(A) receptors involved in learning and memory is currently being evaluated as a novel therapeutic principle for symptomatic memory enhancement.
Collapse
Affiliation(s)
- H Möhler
- Institute of Pharmacology, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.
| | | | | | | | | |
Collapse
|
73
|
|
74
|
Gorobets NY, Yousefi BH, Belaj F, Kappe C. Rapid microwave-assisted solution phase synthesis of substituted 2-pyridone libraries. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.05.100] [Citation(s) in RCA: 152] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
75
|
Street LJ, Sternfeld F, Jelley RA, Reeve AJ, Carling RW, Moore KW, McKernan RM, Sohal B, Cook S, Pike A, Dawson GR, Bromidge FA, Wafford KA, Seabrook GR, Thompson SA, Marshall G, Pillai GV, Castro JL, Atack JR, MacLeod AM. Synthesis and biological evaluation of 3-heterocyclyl-7,8,9,10-tetrahydro-(7,10-ethano)-1,2,4-triazolo[3,4-a]phthalazines and analogues as subtype-selective inverse agonists for the GABA(A)alpha5 benzodiazepine binding site. J Med Chem 2004; 47:3642-57. [PMID: 15214791 DOI: 10.1021/jm0407613] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The identification of a novel series of 7,8,9,10-tetrahydro-(7,10-ethano)-1,2,4-triazolo[3,4-a]phthalazines as GABA(A)alpha5 inverse agonists, which have both binding and functional (efficacy) selectivity for the benzodiazepine binding site of alpha5- over alpha1-, alpha2-, and alpha3-containing GABA(A) receptor subtypes, is described. Binding selectivity was determined to a large part by the degree of planarity of the fused ring system whereas functional selectivity was dependent on the nature of the heterocycle at the 3-position of the triazolopyridazine ring. 3-Furan and 5-methylisoxazole were shown to be optimal for GABA(A)alpha5 functional selectvity. 3-(5-Methylisoxazol-3-yl)-6-(2-pyridyl)methyloxy-1,2,4-triazolo[3,4-a]phthalazine (43) was identified as a full inverse agonist at the GABA(A)alpha5 subtype with functional selectivity over the other GABA(A) receptor subtypes and good oral bioavailability.
Collapse
Affiliation(s)
- Leslie J Street
- Departments of Medicinal Chemistry, Biochemistry, and Pharmacology, Merck Sharp and Dohme Research Laboratories, Neuroscience Research Centre, Terlings Park, Eastwick Road, Harlow, Essex CM20 2QR, UK.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
76
|
Li W, Chen Y, Lam Y. A facile solid-phase synthesis of 3,4,6-trisubstituted-2-pyridones using sodium benzenesulfinate as a traceless linker. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.07.051] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
77
|
Abstract
Anxiety and its disorders have long been known to be familial. Recently, genetic approaches have been used to clarify the role of heredity in the development of anxiety and to probe its neurobiological underpinnings. Twin studies have shown that a significant proportion of the liability to develop any given anxiety disorder is due to genetic factors. Ongoing efforts to map anxiety-related loci in both animals and humans are underway with limited success to date. Animal models have played a large role in furthering our understanding of the genetic basis of anxiety, demonstrating that the genetic factors underlying anxiety are complex and varied. Recent advances in molecular genetic techniques have allowed increasing specificity in the manipulation of gene expression within the central nervous system of the mouse. With this increasing specificity has come the ability to ask and answer precise questions about the mechanisms of anxiety and its treatment.
Collapse
Affiliation(s)
- Joshua A Gordon
- Center for Neurobiology and Behavior, Department of Psychiatry, Columbia University, New York State Psychiatric Institute, New York, NY 10032, USA.
| | | |
Collapse
|
78
|
Isles AR, Davies W, Burrmann D, Burgoyne PS, Wilkinson LS. Effects on fear reactivity in XO mice are due to haploinsufficiency of a non-PAR X gene: implications for emotional function in Turner's syndrome. Hum Mol Genet 2004; 13:1849-55. [PMID: 15238507 DOI: 10.1093/hmg/ddh203] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recent work has indicated altered emotional functioning in Turner's syndrome (TS) subjects (45,XO). We examined the role of X-chromosome deficiency on fear reactivity in X-monosomic mice (39,XO), and found that they exhibited anxiogenic behaviour relative to normal females (40,XX). A molecular candidate for this effect is Steroid sulfatase (Sts) as this is located in the pseudoautosomal region (PAR) of the X-chromosome and consequently is normally biallelically expressed. In addition, the steroid sulfatase enzyme (STS) is putatively linked to fear reactivity by an effect on GABAA receptors via the action of neurosteroids. Real-time PCR demonstrated that levels of Sts mRNA were reduced by half in the brains of 39,XO mice compared with 40,XX, and that expression levels of a number of GABAA subunits previously shown to be important components of fear processing (Gabra3, Gabra1 and Gabrg2) were also altered. However, 40,XY*X mice, in which the Y*X is a small chromosome comprising of a complete PAR and a small non-PAR segment of the X-chromosome, exhibited the same pattern of fear reactivity behaviour as 39,XO animals, but equivalent expression levels of Sts, Gabra1, Gabra3 and Gabrg2 to 40,XX females. This showed that although Sts may cause alterations in GABAA subunit expression, these changes do not result in increased fear reactivity. This suggests an alternative X-chromosome gene, that escapes inactivation, is responsible for the differences in fear reactivity between 39,XO and 40,XX mice. These findings inform the TS data, and point to novel genetic mechanisms that may be of general significance to the neurobiology of fear.
Collapse
Affiliation(s)
- Anthony R Isles
- Neurobiology and Developmental Genetics Programmes, The Babraham Institute, Cambridge, UK
| | | | | | | | | |
Collapse
|
79
|
Crawforth J, Atack JR, Cook SM, Gibson KR, Nadin A, Owens AP, Pike A, Rowley M, Smith AJ, Sohal B, Sternfeld F, Wafford K, Street LJ. Tricyclic pyridones as functionally selective human GABAAα2/3 receptor-ion channel ligands. Bioorg Med Chem Lett 2004; 14:1679-82. [PMID: 15026049 DOI: 10.1016/j.bmcl.2004.01.057] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2003] [Revised: 01/16/2004] [Accepted: 01/21/2004] [Indexed: 10/26/2022]
Abstract
A series of tricyclic pyridones has been evaluated as benzodiazepine site ligands with functional selectivity for the alpha(3) over the alpha(1) containing subtype of the human GABA(A) receptor ion channel. This investigation led to the identification of a high affinity, functionally selective, orally bioavailable benzodiazepine site ligand that demonstrated activity in rodent anxiolysis models and reduced sedation relative to diazepam.
Collapse
Affiliation(s)
- James Crawforth
- Department of Medicinal Chemistry, The Neuroscience Research Centre, Terlings Park, Eastwick Road, Harlow, Essex CM20 2QR, UK.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
80
|
Rudolph U, Möhler H. ANALYSIS OFGABAARECEPTORFUNCTION ANDDISSECTION OF THEPHARMACOLOGY OFBENZODIAZEPINES ANDGENERALANESTHETICSTHROUGHMOUSEGENETICS. Annu Rev Pharmacol Toxicol 2004; 44:475-98. [PMID: 14744255 DOI: 10.1146/annurev.pharmtox.44.101802.121429] [Citation(s) in RCA: 414] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
GABAA receptors are molecular substrates for the regulation of vigilance, anxiety, muscle tension, epileptogenic activity, and memory functions, and the enhancement of GABAA receptor-mediated fast synaptic inhibition is the basis for the pharmacotherapy of various neurological and psychiatric disorders. Two kinds of GABAA receptor-targeted mutant mice have been generated: (a) knockout mice that lack individual GABAA receptor subunits (alpha1, alpha5, alpha6, beta2, beta3, gamma2, delta, and rho1) and (b) knockin mice that carry point mutations affecting the action of modulatory drugs [alpha1(H101R), alpha2(H101R), alpha3(H126R), alpha5(H105R), and beta3(N265M)]. Whereas the knockout mice have provided information primarily with respect to the regulation of subunit gene transcription, receptor assembly, and some physiological functions of individual receptor subtypes, the point-mutated knockin mice in which specific GABAA receptor subtypes are insensitive to diazepam or some general anesthetics have revealed the specific contribution of individual receptor subtypes to the pharmacological spectrum of diazepam and general anesthetics.
Collapse
Affiliation(s)
- Uwe Rudolph
- Institute of Pharmacology and Toxicology, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich.
| | | |
Collapse
|
81
|
Fields AM, Richards TA, Felton JA, Felton SK, Bayer EZ, Ibrahim IN, Kaye AD. Analysis of Responses to Valerian Root Extract in the Feline Pulmonary Vascular Bed. J Altern Complement Med 2003; 9:909-18. [PMID: 14736362 DOI: 10.1089/107555303771952253] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES This study was undertaken to investigate pulmonary vascular response to valerian (Valeriana officinalis) in the feline pulmonary vasculature under constant flow conditions. DESIGN In separate experiments, the effects of NG-L-nitro-L-arginine methyl ester (L-NIO), a nitric oxide synthase inhibitor, glibenclamide, an adenosine triphosphate (ATP)-sensitive potassium (K+) channel blocker, meclofenamate, a nonselective cyclooxygenase (COX) inhibitor, bicuculline, a GABA(A) receptor antagonist, and saclofen, a GABA(B) antagonist, were investigated on pulmonary arterial responses to various agonists in the feline pulmonary vascular bed. These agonists included valerian, muscimol, a GABA(A) agonist, SKF-97541 a GABA(B) agonist, acetylcholine (ACh), and bradykinin, both inducers of nitric oxide synthase, arachidonic acid, a COX substrate, and pinacidil, an ATP-sensitive K+ channel activator, during increased tone conditions induced by the thromboxane A2 mimic, U46619. SETTINGS/LOCATION Laboratory investigation. SUBJECTS Mongrel cats of either gender. INTERVENTIONS Injections of the abovementioned agonists and antagonists were given. OUTCOME MEASURES Baseline pulmonary tone, responses to the agonists, and responses to the agonists after injections of antagonists were all measured via a pulmonary catheter transducer and recorded. RESULTS Valerian root extract is a potent smooth muscle dilator in the feline pulmonary vascular bed. The vasodilatory effects of valerian root extract were unchanged after the administration of L-NIO, glibenclamide, and meclofenamate. These effects were ablated, however, by both saclofen and bicuculline. The ability of saclofen and bicuculline to modulate the dilatory effects of valerian root extract was not statistically different. CONCLUSIONS The vasodilatory effects of valerian root extract are mediated by a nonselective GABA mechanism.
Collapse
|
82
|
Fritschy JM, Brünig I. Formation and plasticity of GABAergic synapses: physiological mechanisms and pathophysiological implications. Pharmacol Ther 2003; 98:299-323. [PMID: 12782242 DOI: 10.1016/s0163-7258(03)00037-8] [Citation(s) in RCA: 244] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
gamma-Aminobutyric acid(A) (GABA(A)) receptors mediate most of the fast inhibitory neurotransmission in the CNS. They represent a major site of action for clinically relevant drugs, such as benzodiazepines and ethanol, and endogenous modulators, including neuroactive steroids. Alterations in GABA(A) receptor expression and function are thought to contribute to prevalent neurological and psychiatric diseases. Molecular cloning and immunochemical characterization of GABA(A) receptor subunits revealed a multiplicity of receptor subtypes with specific functional and pharmacological properties. A major tenet of these studies is that GABA(A) receptor heterogeneity represents a key factor for fine-tuning of inhibitory transmission under physiological and pathophysiological conditions. The aim of this review is to highlight recent findings on the regulation of GABA(A) receptor expression and function, focusing on the mechanisms of sorting, targeting, and synaptic clustering of GABA(A) receptor subtypes and their associated proteins, on trafficking of cell-surface receptors as a means of regulating synaptic (and extrasynaptic) transmission on a short-time basis, on the role of endogenous neurosteroids for GABA(A) receptor plasticity, and on alterations of GABA(A) receptor expression and localization in major neurological disorders. Altogether, the findings presented in this review underscore the necessity of considering GABA(A) receptor-mediated neurotransmission as a dynamic and highly flexible process controlled by multiple mechanisms operating at the molecular, cellular, and systemic level. Furthermore, the selected topics highlight the relevance of concepts derived from experimental studies for understanding GABA(A) receptor alterations in disease states and for designing improved therapeutic strategies based on subtype-selective drugs.
Collapse
Affiliation(s)
- Jean-Marc Fritschy
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
| | | |
Collapse
|
83
|
Chen X, Wang W. Chapter 32. The use of bioisosteric groups in lead optimization. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2003. [DOI: 10.1016/s0065-7743(03)38033-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
|
84
|
Gibson KR, Hitzel L, Mortishire-Smith RJ, Gerhard U, Jelley RA, Reeve AJ, Rowley M, Nadin A, Owens AP. Synthesis and conformational dynamics of tricyclic pyridones containing a fused seven-membered ring. J Org Chem 2002; 67:9354-60. [PMID: 12492338 DOI: 10.1021/jo026411a] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A new synthetic approach to tricyclic pyridones bearing a fused seven-membered ring is described. These compounds exhibit atropisomerism and exist in enantiomeric forms. Chiral HPLC separation of the enantiomers has allowed the rates of racemization to be measured and hence the free energy barrier for flipping the seven-membered ring to be deduced. Introduction of a further element of planar chirality leads to diastereomeric atropisomerism. The rate of interconversion of the diastereomers has been quantified by 2D EXSY NMR spectroscopy allowing a full description of the conformational dynamics of the system.
Collapse
Affiliation(s)
- Karl R Gibson
- Medicinal Chemistry Department, Merck Sharp & Dohme Research Laboratories, The Neuroscience Research Centre, Terlings Park, Harlow, Essex CM20 2QR, UK
| | | | | | | | | | | | | | | | | |
Collapse
|