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Mengod G, Vilaró MT, Cortés R, López-Giménez JF, Raurich A, Palacios JM. Chemical Neuroanatomy of 5-HT Receptor Subtypes in the Mammalian Brain. THE SEROTONIN RECEPTORS 2006. [DOI: 10.1007/978-1-59745-080-5_10] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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López-Rodríguez ML, Morcillo MJ, Fernández E, Benhamú B, Tejada I, Ayala D, Viso A, Campillo M, Pardo L, Delgado M, Manzanares J, Fuentes JA. Synthesis and Structure−Activity Relationships of a New Model of Arylpiperazines. 8.1Computational Simulation of Ligand−Receptor Interaction of 5-HT1AR Agonists with Selectivity over α1-Adrenoceptors. J Med Chem 2005; 48:2548-58. [PMID: 15801844 DOI: 10.1021/jm048999e] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have designed and synthesized a new series of arylpiperazines V exhibiting high 5-HT(1A)R affinity and selectivity over alpha(1)-adrenoceptors. The new selective 5-HT(1A)R ligands contain a hydantoin (m = 0) or diketopiperazine (m = 1) moiety and an arylpiperazine moiety separated by one methylene unit (n = 1). The aryl substituent of the piperazine moiety (Ar) consists of different benzofused rings mimicking the favorable voluminous substituents at ortho and meta positions predicted by 3D-QSAR analysis in the previously reported series I. In particular, (S)-2-[[4-(naphth-1-yl)piperazin-1-yl]methyl]-1,4-dioxoperhydropyrrolo[1,2-a]pyrazine [(S)-9, CSP-2503] (5-HT(1A), K(i) = 4.1 nM; alpha(1), K(i) > 1000 nM) has been pharmacologically characterized as a 5-HT(1A)R agonist at somatodendritic and postsynaptic sites, endowed with anxiolytic properties. Ligand (S)-9 is predicted, in computer simulations, to bind Asp(3.32) in TMH 3, Thr(5.39) and Ser(5.42) in TMH 5, and Trp(6.48) in TMH 6. We propose that agonists modify, by means of an explicit hydrogen bond, the conformation of Trp(6.48) from pointing toward TMH 7, in the inactive gauche+ conformation, to pointing toward the ligand binding site, in the active trans conformation.
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Affiliation(s)
- María L López-Rodríguez
- Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense, E-28040 Madrid, Spain
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Manuel-Apolinar L, Rocha L, Pascoe D, Castillo E, Castillo C, Meneses A. Modifications of 5-HT4 receptor expression in rat brain during memory consolidation. Brain Res 2005; 1042:73-81. [PMID: 15823255 DOI: 10.1016/j.brainres.2005.02.020] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2004] [Revised: 02/01/2005] [Accepted: 02/07/2005] [Indexed: 11/24/2022]
Abstract
Pharmacological evidence indicates a specific role of 5-HT(4) receptors on memory function. These receptors are members of G-protein-coupled 7-transmembrane domain receptor superfamily, are positively coupled to adenylyl cyclase, and are heterogeneously located in some structures important for memory, such as the hippocampus and cortical regions. To further clarify 5-HT(4) receptors' role in memory, the expression of these receptors in passive (P3) untrained and autoshaping (A3) trained (3 sessions) adult (3 months) and old (P9 or A9; 9 months) male rats was determined by autoradiography. Adult trained (A3) rats showed a better memory respect to old trained (A9). Using [(3)H] GR113808 as ligand (0.2 nM specific activity 81 Ci/mmol) for 5-HT(4) receptor expression, 29 brain areas were analyzed, 16 areas of A3 and 17 of A9 animals displayed significant changes. The medial mammillary nucleus of A3 group showed diminished 5-HT(4) receptor expression, and in other 15 brain areas of A3 or 10 of A9 animals, 5-HT(4) receptors were increased. Thus, for A3 rats, 5-HT(4) receptors were augmented in olfactory lobule, caudate putamen, fundus striatum, CA2, retrosplenial, frontal, temporal, occipital, and cingulate cortex. Also, 5-HT(4) receptors were increased in olfactory tubercule, hippocampal CA1, parietal, piriform, and cingulate cortex of A9. However, hippocampal CA2 and CA3 areas, and frontal, parietal, and temporal cortex of A9 rats, expressed less 5-HT(4) receptors. These findings suggest that serotonergic activity, via 5-HT(4) receptors in hippocampal, striatum, and cortical areas, mediates memory function and provides further evidence for a complex and regionally specific regulation over 5-HT receptor expression during memory formation.
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Modica M, Romeo G, Materia L, Russo F, Cagnotto A, Mennini T, Gáspár R, Falkay G, Fülöp F. Synthesis and binding properties of novel selective 5-HT3 receptor ligands. Bioorg Med Chem 2005; 12:3891-901. [PMID: 15210156 DOI: 10.1016/j.bmc.2004.04.043] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2003] [Accepted: 04/30/2004] [Indexed: 11/18/2022]
Abstract
This work reports on the synthesis and affinities for the 5-HT(3) versus the 5-HT(4) receptor of new piperazinyl-substituted thienopyrimidine derivatives 20-45 with a view to identify potent and selective ligands for the 5-HT(3) receptor. Some of the new compounds show good affinity for the 5-HT(3) receptor and, notably, do not display any affinity for the 5-HT(4) receptor. 4-(4-Methyl-1-piperazinyl)-2-methylthio-6,7-dihydro-5H-cyclopenta[4,5]thieno[2,3-d]pyrimidine 31 exhibits the highest affinity for the 5-HT(3) receptor (Ki = 33 nM) and behaves as noncompetitive antagonist.
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Affiliation(s)
- Maria Modica
- Dipartimento di Scienze Farmaceutiche, Università di Catania, viale A. Doria 6, 95125 Catania, Italy.
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55
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Vilaró MT, Cortés R, Mengod G. Serotonin 5-HT4receptors and their mRNAs in rat and guinea pig brain: Distribution and effects of neurotoxic lesions. J Comp Neurol 2005; 484:418-39. [PMID: 15770652 DOI: 10.1002/cne.20447] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Serotonin 5-HT4 receptors are widely distributed in the periphery and in brain, where they modulate the release of various neurotransmitters and have been implicated in learning and memory. Nine C-terminal splice variants of this receptor have been cloned in mammalian species. In the rat, three such variants have been described: 5-HT4(a), 5-HT4(b), and 5-HT4(e). In the present study, we have examined several aspects of the distribution of these receptors in brain. First, we provide, in rat and guinea pig, a detailed comparison of the distribution of 5-HT4 receptors labeled by the antagonist [125I]-SB 207710 with the distribution of their encoding mRNA visualized by in situ hybridization histochemistry (ISHH). The results suggest that, in several projection systems (striato-nigral and striato-pallidal pathways, projection from dentate granule cells to field CA3, habenulo-interpeduncular pathway), 5-HT4 receptors are located both somatodendritically and axonally. Second, we have analyzed the distribution of mRNA for the three known rat splice variants by reverse transcription-polymerase chain reaction (RT-PCR) and by ISHH. RT-PCR indicates that all three variants are widely distributed, with 5-HT4(b) mRNA being present in all regions examined (olfactory tubercle, striatum, hippocampus, inferior colliculus, substantia nigra, parietal cortex) and 5-HT4(a) and 5-HT4(e) showing a somewhat more restricted distribution. In other regions (periaqueductal gray, reticular formation, medial septum, diagonal band), faint ISHH signals are observed for 5-HT4(a)+4(e) mRNAs, whereas 5-HT4(b) mRNA signals are almost undetectable. Finally, neurotoxic lesions of basal ganglia components in guinea pig also indicate a location of these receptors on terminals of striatal projection neurons.
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Affiliation(s)
- M Teresa Vilaró
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona 08036, Spain.
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56
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Baudy RB. Agents for the treatment of neurodegenerative diseases: January - June 1997. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.7.10.1129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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57
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Baudy RB. Agents for the treatment of neurodegenerative diseases: January - June 1998. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.8.10.1269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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58
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Abstract
Preclinical studies have contributed greatly to our understanding of the neurochemical pathways associated with the development and maintenance of alcohol-seeking behaviour. These studies have demonstrated the important role of serotonin pathways, particularly as they relate to dopaminergic function, which mediates alcohol-induced reward associated with its abuse liability. Naturally, this has led to the study of serotonergic agents as treatments for alcoholism.SSRIs do not appear to be effective treatment for a heterogeneous alcoholic group. However, they may be useful as treatment for late-onset alcoholics, or alcoholism complicated by comorbid major depression. Buspirone, a serotonin 5-HT1A partial agonist, does not appear to be an effective treatment for alcoholics without comorbid disease. Buspirone may, however, have some utility for treating alcoholics with comorbid anxiety disorder. The 5-HT2 antagonist ritanserin, at pharmacologically relevant clinical doses, does not appear to be an effective treatment for alcoholism. Ondansetron, a 5-HT3 antagonist, is an efficacious and promising medication for the treatment of early-onset alcoholism. Preliminary evidence suggests that combining the mu antagonist naltrexone with the 5-HT3 antagonist ondansetron promises to be more effective for treating alcoholism than either alone. The differential treatment effect of SSRIs and ondansetron among various subtypes of alcoholic is intriguing. Future research is needed to understand more clearly the molecular genetic differences and the interactions of such differences with the environment that typify a particular alcoholic subtype. Such an understanding could enable us to make comfortable predictions as to which alcoholic subtype might respond best to a particular serotonergic agent, which could then be provided.
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Affiliation(s)
- Bankole A Johnson
- University of Virginia Health System, Charlottesville, Virginia 22908-0623, USA.
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59
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Boess FG, Hendrix M, van der Staay FJ, Erb C, Schreiber R, van Staveren W, de Vente J, Prickaerts J, Blokland A, Koenig G. Inhibition of phosphodiesterase 2 increases neuronal cGMP, synaptic plasticity and memory performance. Neuropharmacology 2004; 47:1081-92. [PMID: 15555642 DOI: 10.1016/j.neuropharm.2004.07.040] [Citation(s) in RCA: 244] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2004] [Revised: 06/02/2004] [Accepted: 07/28/2004] [Indexed: 10/25/2022]
Abstract
An essential element of the signalling cascade leading to synaptic plasticity is the intracellular second messenger molecule guanosine 3',5'-cyclic monophosphate (cGMP). Using the novel, potent, and selective inhibitor Bay 60-7550, we show that the enzyme 3',5'-cyclic nucleotide phosphodiesterase type 2 (PDE2) is responsible for the degradation of newly synthesized cGMP in cultured neurons and hippocampal slices. Inhibition of PDE2 enhanced long-term potentiation of synaptic transmission without altering basal synaptic transmission. Inhibition of PDE2 also improved the performance of rats in social and object recognition memory tasks, and reversed MK801-induced deficits in spontaneous alternation in mice in a T-maze. Our data provide strong evidence that inhibition of PDE2 can improve memory functions by enhancing neuronal plasticity.
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Affiliation(s)
- Frank G Boess
- Bayer Healthcare AG, Pharma Research CNS, 42096 Wuppertal-Elberfeld, Germany
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60
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Becker DP, Flynn DL, Shone RL, Gullikson G. Azaadamantane benzamide 5-HT4 agonists: gastrointestinal prokinetic SC-54750. Bioorg Med Chem Lett 2004; 14:5509-12. [PMID: 15482914 DOI: 10.1016/j.bmcl.2004.09.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2004] [Revised: 09/01/2004] [Accepted: 09/03/2004] [Indexed: 10/26/2022]
Abstract
Azaadamantanone 1 was converted to a series of aminoazaadamantane benzamides 9a-d, which were profiled for serotonin receptor activity. Aminomethylazaadamantane SC-54750 is a potent 5-HT(4) agonist and 5-HT(3) antagonist with in vivo efficacy in gastroparesis models and also inhibits cisplatin-induced emesis.
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Affiliation(s)
- Daniel P Becker
- Departments of Medicinal Chemistry and Pharmacology, Pfizer Research & Development, 4901 Searle Parkway, Skokie, IL 60077, USA.
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61
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Beattie DT, Smith JAM, Marquess D, Vickery RG, Armstrong SR, Pulido-Rios T, McCullough JL, Sandlund C, Richardson C, Mai N, Humphrey PPA. The 5-HT4 receptor agonist, tegaserod, is a potent 5-HT2B receptor antagonist in vitro and in vivo. Br J Pharmacol 2004; 143:549-60. [PMID: 15466450 PMCID: PMC1575425 DOI: 10.1038/sj.bjp.0705929] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
1 Tegaserod (Zelnorm) is a potent 5-hydroxytryptamine4 (5-HT4) receptor agonist with clinical efficacy in disorders associated with reduced gastrointestinal motility and transit. The present study investigated the interaction of tegaserod with 5-HT2 receptors, and compared its potency in this respect to its 5-HT4 receptor agonist activity. 2 Tegaserod had significant binding affinity for human recombinant 5-HT2A, 5-HT2B and 5-HT2C receptors (pKi=7.5, 8.4 and 7.0, respectively). The 5-HT2B receptor-binding affinity of tegaserod was identical to that at human recombinant 5-HT4(c) receptors (mean pKi=8.4) in human embryonic kidney-293 (HEK-293) cells stably transfected with the human 5-HT4(c) receptor. 3 Tegaserod (0.1-3 microm) inhibited 5-HT-mediated contraction of the rat isolated stomach fundus potently (pA2=8.3), consistent with 5-HT(2B) receptor antagonist activity. Tegaserod produced, with similar potency, an elevation of adenosine 3',5' cyclic monophosphate in HEK-293 cells stably transfected with the human 5-HT4(c) receptor (mean pEC50=8.6), as well as 5-HT4) receptor-mediated relaxation of the rat isolated oesophagus (mean pEC50=8.2) and contraction of the guinea-pig isolated colon (mean pEC50=8.3). 4 Following subcutaneous administration, tegaserod (0.3 or 1 mg kg(-1)) inhibited contractions of the stomach fundus in anaesthetized rats in response to intravenous dosing of alpha-methyl 5-HT (0.03 mg kg(-1)) and BW 723C86 (0.3 mg kg(-1)), selective 5-HT2B receptor agonists. At similar doses, tegaserod (1 and 3 mg kg(-1) subcutaneously) evoked a 5-HT4 receptor-mediated increase in colonic transit in conscious guinea-pigs. 5 The data from this study indicate that tegaserod antagonizes 5-HT2B receptors at concentrations similar to those that activate 5-HT4 receptors. It remains to be determined whether this 5-HT2B receptor antagonist activity of tegaserod contributes to its clinical profile.
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Affiliation(s)
- D T Beattie
- Theravance, Inc., 901 Gateway Boulevard, South San Francisco, CA 94080, USA.
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Paolucci E, Berretta N, Tozzi A, Bernardi G, Mercuri NB. Depression of mGluR-mediated IPSCs by 5-HT in dopamine neurons of the rat substantia nigra pars compacta. Eur J Neurosci 2004; 18:2743-50. [PMID: 14656323 DOI: 10.1111/j.1460-9568.2003.03015.x] [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] [Indexed: 11/30/2022]
Abstract
Dopamine neurons of the substantia nigra pars compacta receive a prominent serotonin (5-HT) projection from the dorsal raphe nucleus and important functional interactions between the serotonergic and the dopaminergic system have been postulated. In the present report we examined the role of 5-HT in the modulation of the metabotropic glutamate receptor-mediated inhibitory postsynaptic current (mGluR-IPSC) in midbrain dopamine neurons, and we found a reversible depression of this synaptic response at concentrations of 5-HT ranging from 100 nm to 30 microm (EC50 1.06 microm). This resulted in a shift towards excitation of the overall dopamine neuron response to glutamatergic synaptic input. This effect was not because of a direct modulation of the Ca2+-sensitive K+ conductances underlying the mGluR-IPSC, but was associated with a decrease in the intracellular calcium signal triggered by mGluR stimulation. Similar results were obtained with alpha-methyl-5-hydroxytryptamine and 5-methoxytryptamine, but not with 5-carboxamidotryptamine or 1-(3-chlorophenyl) piperazine. No significant depression of the mGluR-IPSC by 5-HT was observed in the presence of the 5-HT2 antagonist cinanserin or the 5-HT4 receptor antagonist RS 23597-190, whereas the 5-HT2C antagonist RS 102221 was ineffective. Our results demonstrate a powerful inhibition of the mGluR-IPSC by 5-HT in midbrain dopamine neurons, most probably through stimulation of 5-HT2A and 5-HT4 receptors.
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Affiliation(s)
- E Paolucci
- Fondazione Santa Lucia IRCCS, Experimental Neurology, Via Ardeatina 306, 00179 Rome, Italy
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63
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Varnäs K, Halldin C, Pike VW, Hall H. Distribution of 5-HT4 receptors in the postmortem human brain--an autoradiographic study using [125I]SB 207710. Eur Neuropsychopharmacol 2003; 13:228-34. [PMID: 12888181 DOI: 10.1016/s0924-977x(03)00009-9] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The autoradiographic distribution of the 5-HT4 receptor was described using human postmortem brain sections and the selective radioligand [125I]SB 207710 [(1-n-butyl-4-piperidinyl)methyl-8-amino-7-[125I]iodo-1,4-benzodioxane-5-carboxylate]. The specific binding was highest in regions of the basal ganglia (caudate nucleus, putamen, nucleus accumbens, globus pallidus and substantia nigra) and the hippocampal formation (CA1 and subiculum). In the neocortex, the binding showed a distinct lamination pattern with high levels in superficial layers and a band displaying lower levels in deep cortical layers. The results confirm previous studies on the distribution of 5-HT4 receptors in the human brain in vitro and provide high-resolution correlates for in vivo imaging studies using the radioligand recently developed for single photon emission tomography (SPET), [123I]SB 207710.
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Affiliation(s)
- Katarina Varnäs
- Karolinska Institutet, Department of Clinical Neuroscience, Psychiatry Section, Karolinska Hospital, S-17176 Stockholm, Sweden
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López-Rodríguez ML, Morcillo MJ, Fernández E, Benhamú B, Tejada I, Ayala D, Viso A, Olivella M, Pardo L, Delgado M, Manzanares J, Fuentes JA. Design and synthesis of S-(-)-2-[[4-(napht-1-yl)piperazin-1-yl]methyl]-1,4-dioxoperhydropyrrolo[1,2-a]pyrazine (CSP-2503) using computational simulation. A 5-HT1A receptor agonist. Bioorg Med Chem Lett 2003; 13:1429-32. [PMID: 12668005 DOI: 10.1016/s0960-894x(03)00160-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Based on a computational model for 5-HT(1A)R-ligand interaction and QSAR studies, we have designed and synthesized a new series of arylpiperazines 2-8 which exhibit high 5-HT(1A)R affinity and selectivity over alpha(1)-adrenergic receptors. Among them, compound CSP-2503 (4) has been pharmacologically characterized as a 5-HT(1A)R agonist at somatodendritic and postsynaptic sites, endowed with anxiolytic properties.
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Affiliation(s)
- María L López-Rodríguez
- Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense, E-28040 Madrid, Spain.
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65
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Cohen JE, Onyike CU, McElroy VL, Lin AH, Abrams TW. Pharmacological characterization of an adenylyl cyclase-coupled 5-HT receptor in aplysia: comparison with mammalian 5-HT receptors. J Neurophysiol 2003; 89:1440-55. [PMID: 12611939 DOI: 10.1152/jn.01004.2002] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We attempted to identify compounds that are effective in blocking the serotonin (5-hydroxytryptamine, 5-HT) receptor(s) that activate adenylyl cyclase (AC) in Aplysia CNS. We call this class of receptor 5-HT(apAC). Eight of the 14 antagonists tested were effective against 5-HT(apAC) in CNS membranes with the following rank order of potency: methiothepin > metergoline approximately fluphenazine > clozapine > cyproheptadine approximately risperidone approximately ritanserin > NAN-190. GR-113808, olanzapine, Ro-04-6790, RS-102221, SB-204070, and spiperone were inactive. Methiothepin completely blocked 5-HT stimulation of AC with a K(b) of 18 nM. Comparison of the pharmacological profile of the 5-HT(apAC) receptor with those of mammalian 5-HT receptor subtypes suggested it most closely resembles the 5-HT(6) receptor. AC stimulation in Aplysia sensory neuron (SN) membranes was also blocked by methiothepin. Methiothepin substantially inhibited two effects of 5-HT on SN firing properties that are mediated by a cAMP-dependent reduction in S-K(+) current: spike broadening in tetraethylammonium/nifedipine and increased excitability. Consistent with cyproheptadine blocking 5-HT stimulation of AC, cyproheptadine also blocked the 5-HT-induced increase in SN excitability. Methiothepin was less effective in blocking AC-mediated modulatory effects of 5-HT in electrophysiological experiments on SNs than in blocking AC stimulation in CNS or SN membranes. This reduction in potency appears to be due to effects of the high ionic strength of physiological saline on the binding of this antagonist to the receptor. Methiothepin also antagonized AC-coupled dopamine receptors but not AC-coupled small cardioactive peptide receptors. In conjunction with other pharmacological probes, this antagonist should be useful in analyzing the role of 5-HT in various forms of neuromodulation in Aplysia.
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Affiliation(s)
- Jonathan E Cohen
- Department of Pharmacology, University of Maryland School of Medicine, BRB 4-002, Baltimore 21201-1559, USA
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Inoue M, Kitazawa T, Cao J, Taneike T. 5-HT7 receptor-mediated relaxation of the oviduct in nonpregnant proestrus pigs. Eur J Pharmacol 2003; 461:207-18. [PMID: 12586216 DOI: 10.1016/s0014-2999(03)01312-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The effects of 5-hydroxytryptamine (5-HT) on the muscle tonus of the ampulla and isthmus of the oviduct isolated from nonpregnant proestrus pigs were investigated, and the 5-HT receptor subtype and mechanisms of the responses were analyzed. 5-HT (1 nM-10 microM) caused a relaxation of longitudinal and circular muscles of the isthmus in a concentration-dependent manner. Tetrodotoxin did not change the relaxation, indicating a direct action of 5-HT on smooth muscle cells. The EC(50) value in the longitudinal muscle was significantly lower than that in the circular muscle but the maximum relaxations were similar. 5-HT also caused a relaxation of both muscle layers in the ampulla but the maximum relaxation of both muscles was smaller than that of the isthmus. 5-Carboxamidotryptamine (5-CT), 5-methoxytryptamine (5-MeOT) and (+/-)-8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) mimicked the relaxation of the isthmic longitudinal muscle by 5-HT, and the ranking order was 5-CT>5-HT>5-MeOT>8-OH-DPAT. On the other hand, oxymethazoline, 2-methyl-5-hydroxytryptamine (2-methyl-5-HT), alpha-methyl-5-hydroxytryptamine (alpha-methyl-5-HT), [endo-N-8-methyl-8-azabicyclo-(3,2,1) oct-3-yl]-2,3-dihydro-3-ethyl-2-oxo-1H-benzimidazol-1-carboxamide (BIMU-1), ergotamine and dihydroergotamine were less effective. The relaxation by 5-HT was not decreased by ketanserin, 2-methoxy-4-amino-5-chlorobenzoic acid 2-(diethylamino)ethyl ester (tropisetron) or [1[2-(methylsulphonyl) amino ethyl]-4-piperidinyl]methyl-1-methyl-1H-indole-3-carboxylate (GR113808) but was antagonized by the following compounds in a competitive manner (with pK(b) values in parentheses): 2a-[4-(4-phenyl-1,2,3,6-tetrahydropyridyl)butyl]-2a,3,4,5-tetrahydro-benzo[cd]indol-2(1H)-one (DR4004, 9.31), methiothepin (8.91), methysergide (7.95), metergoline (7.98), mianserin (7.69), mesulergine (8.4), spiperone (6.86) and clozapine (7.4). The correlation of these pK(b) values with pK(i) values of cloned 5-HT(7) receptor or pA(2) values of porcine uterus was high and significant. 4-(3-Butoxy-4-methoxybenzyl)-imidazolidin-2-one (Ro20-1724) significantly enhanced the relaxation by 5-HT but zaprinast, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) and L-nitroarginine methylester (L-NAME) did not change the responses to 5-HT. 5-HT increased cyclic AMP in the isthmic oviduct. Ampulla and isthmus contained a single class of [3H]5-CT binding sites with a similar K(d) value (0.4 nM), but the density of the receptors in the isthmus was 2.4 times higher than that in the ampulla. A significant correlation was found between the pK(i) values in the oviduct and those of the cloned 5-HT(7) receptors. Isoprenaline, sodium nitroprusside, vasoactive intestinal peptide and pituitary adenylate cyclase activating peptide were less effective in causing the relaxation of the oviduct. In conclusion, the 5-HT receptor, functionally correlated to the 5-HT(7) type, mediates the relaxation of the porcine oviduct by 5-HT through an increase in intracellular cyclic AMP. The degrees of 5-HT-induced relaxation in the isthmus and ampulla of the oviduct were different due to the heterogeneous distribution of 5-HT(7) receptors. The strongest relaxation through 5-HT(7) receptor activation suggests that 5-HT plays an important physiological role in the regulation of porcine oviduct contractility.
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Affiliation(s)
- Mayuko Inoue
- Department of Pharmacology, School of Veterinary Medicine, Rakuno Gakuen University, 582 Bunkyodai-midorimachi, Ebetsu, Hokkaido 069-8501, Japan
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67
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Affiliation(s)
- Michel Langlois
- CNRS-BIOCIS (UPRES A 8076), INSERM U-446, Institut de Signalisation et Innovation Thérapeutique (IFR-ISIT), Faculté de Pharmacie, Université de Paris-Sud, 92296 Châtenay-Malabry, France.
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Claeysen S, Joubert L, Sebben M, Bockaert J, Dumuis A. A single mutation in the 5-HT4 receptor (5-HT4-R D100(3.32)A) generates a Gs-coupled receptor activated exclusively by synthetic ligands (RASSL). J Biol Chem 2003; 278:699-702. [PMID: 12441358 DOI: 10.1074/jbc.c200588200] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To better understand G-protein-coupled receptor (GPCRs) signaling, cellular and animal physiology, as well as gene therapy, a new tool has recently been proposed. It consists of GPCR mutants that are insensitive to endogenous ligands but sensitive to synthetic ligands. These GPCRs are called receptor activated solely by synthetic ligands (RASSL). Only two examples of such engineered receptors have been described so far: one G(i)-coupled (opioid receptors) and one G(s)-coupled (beta(2)-adrenergic receptors). Here, we describe the first RASSL related to serotonin receptors (D100(3.32)A G(s)-coupled 5-HT(4) receptor or 5-HT(4)-RASSL). 5-HT(4)-RASSL is generated by a single mutation, is totally insensitive to serotonin (5-HT), and still responds to synthetic ligands. These ligands have affinities in the range of nanomolar concentrations for the mutant receptor and exhibit full efficacy. More interestingly, two synthetic ligands behave as antagonists on the wild type but as agonists on the 5-HT(4)-RASSL.
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Affiliation(s)
- Sylvie Claeysen
- Centre National de la Recherche Scientifique, UPR 9023, 141 rue de la Cardonille, 34094 Montpellier, Cedex 5, France
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69
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Kikuchi C, Suzuki H, Hiranuma T, Koyama M. New tetrahydrobenzindoles as potent and selective 5-HT(7) antagonists with increased In vitro metabolic stability. Bioorg Med Chem Lett 2003; 13:61-4. [PMID: 12467617 DOI: 10.1016/s0960-894x(02)00842-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Chemical modifications of compound 1 (DR4004), a potent, selective antagonist of the 5-HT(7) receptor, were conducted with the aim of improving its metabolic stability. Halogenation of putative sites of oxidative metabolism afforded compounds 7-10, which retained high affinity and selectivity for the 5-HT(7) receptor, and showed increased in vitro metabolic stability. Compound 10 (DR4485) showed oral bioavailability, and should be a useful tool for evaluating the therapeutic potential of 5-HT(7) antagonists.
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Affiliation(s)
- Chika Kikuchi
- Pharmaceutical Research Center, Meiji Seika Kaisha Ltd., 760Morooka-cho, Kohoku-ku, Yokohama 222-8567, Japan.
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70
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Hinschberger A, Butt S, Lelong V, Boulouard M, Dumuis A, Dauphin F, Bureau R, Pfeiffer B, Renard P, Rault S. New benzo[h][1,6]naphthyridine and azepino[3,2-c]quinoline derivatives as selective antagonists of 5-HT4 receptors: binding profile and pharmacological characterization. J Med Chem 2003; 46:138-47. [PMID: 12502367 DOI: 10.1021/jm020954v] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of benzo[h][1,6]naphthyridine and azepino[3,2-c]quinoline derivatives were prepared and evaluated to determine the necessary requirements for high affinity on the 5-HT(4) receptors and high selectivity versus other receptors. The compounds were synthesized by substituting the chlorine atom of benzonaphthyridines and azepinoquinolines with various N-alkyl-4-piperidinylmethanolates. They were evaluated in binding assays with [(3)H]GR 113808 as the 5-HT(4) receptor radioligand. The affinity values (K(i) or inhibition percentages) depended upon the substituent on the aromatic ring on one hand and the substituent on the lateral piperidine chain on the other hand. A chlorine atom produced a marked drop in activity while a N-propyl or N-butyl group gave compounds with nanomolar affinities (1 < K(i) < 10 nM). Among the most potent ligands (3a, 4a, 5a), 4a was selected on the basis of its high affinity and selectivity for pharmacological screening and was evaluated in vivo in specific tests. This compound reveals itself as an antagonist/low partial agonist in the COS-7 cells stably expressing the 5-HT(4(a)) receptor. Derivative 4a also showed in vivo potent analgesic activity in the writhing test at very low doses.
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71
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López-Rodríguez ML, Murcia M, Benhamú B, Viso A, Campillo M, Pardo L. Benzimidazole derivatives. 3. 3D-QSAR/CoMFA model and computational simulation for the recognition of 5-HT(4) receptor antagonists. J Med Chem 2002; 45:4806-15. [PMID: 12383006 DOI: 10.1021/jm020807x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A three-dimensional quantitative structure-affinity relationship study (3D-QSAR), using the comparative molecular field analysis (CoMFA) method, and subsequent computational simulation of ligand recognition have been successfully applied to explain the binding affinities for the 5-HT(4) receptor (5-HT(4)R) of a series of benzimidazole-4-carboxamides and carboxylates derivatives 1-24. The K(i) values of these compounds are in the range from 0.11 to 10 000 nM. The derived 3D-QSAR model shows high predictive ability (q(2) = 0.789 and r(2) = 0.997). Steric (contribution of 43.5%) and electrostatic (50.3%) fields and solvation energy (6.1%) of this novel class of 5-HT(4)R antagonists are relevant descriptors for structure-activity relationships. Computational simulation of the complexes between the benzimidazole-4-carboxamide UCM-21195 (5) and the carboxylate UCM-26995 (21) and a 3D model of the transmembrane domain of the 5-HT(4)R, constructed using the reported crystal structure of rhodopsin, have allowed us to define the molecular details of the ligand-receptor interaction that includes (i) the ionic interaction between the NH group of the protonated piperidine of the ligand and the carboxylate group of Asp(3.32), (ii) the hydrogen bond between the carbonyl oxygen of the ligand and the hydroxyl group of Ser(5.43), (iii) the hydrogen bond between the NH group of Asn(6.55) and the aromatic ring of carboxamides or the ether oxygen of carboxylates, (iv) the interaction of the electron-rich clouds of the aromatic ring of Phe(6.51) and the electron-poor hydrogens of the carbon atoms adjacent to the protonated piperidine nitrogen of the ligand, and (v) the pi-sigma stacking interaction between the benzimidazole system of the ligand and the benzene ring of Tyr(5.38). Moreover, the noticeable increase in potency at the 5-HT(4)R sites, by the introduction of a chloro or bromo atom at the 6-position of the aromatic ring, is attributed to the additional electrostatic and van der Waals interaction of the halogen atom in a small cavity located between transmembrane domains 5 and 6.
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Affiliation(s)
- María L López-Rodríguez
- Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain.
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72
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Kikuchi C, Hiranuma T, Koyama M. Tetrahydrothienopyridylbutyl-tetrahydrobenzindoles: new selective ligands of the 5-HT(7) receptor. Bioorg Med Chem Lett 2002; 12:2549-52. [PMID: 12182857 DOI: 10.1016/s0960-894x(02)00485-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The synthesis and the affinity for the 5-HT(7) receptor and other receptors of a novel series of fused-ring tetrahydropyridine derivatives are described. Some of the compounds showed high affinity for the 5-HT(7) receptor. Tetrahydrothienopyridylbutyl-tetrahydrobenzindoles and are potent ligands for the 5-HT(7) receptor, with high selectivity over the 5-HT(2) receptor and other receptors. These compounds should be useful tools for clarifying the biological role of the 5-HT(7) receptor.
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Affiliation(s)
- Chika Kikuchi
- Pharmaceutical Research Center, Meiji Seika Kaisha, Ltd., 760Morooka-cho, Kohoku-ku, 222-8567, Yokohama, Japan.
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73
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Abstract
Cortical neuromodulatory transmitter systems refer to those classical neurotransmitters such as acetylcholine and monoamines, which share a number of common features. For instance, their centers are located in subcortical regions and send long projection axons to innervate the cortex. The same transmitter can either excite or inhibit cortical neurons depending on the composition of postsynaptic transmitter receptor subtypes. The overall functions of these transmitters are believed to serve as chemical bases of arousal, attention and motivation. The anatomy and physiology of neuromodulatory transmitter systems and their innervations in the cerebral cortex have been well characterized. In addition, ample evidence is available indicating that neuromodulatory transmitters also play roles in development and plasticity of the cortex. In this article, the anatomical organization and physiological function of each of the following neuromodulatory transmitters, acetylcholine, noradrenaline, serotonin, dopamine, and histamine, in the cortex will be described. The involvement of these transmitters in cortical plasticity will then be discussed. Available data suggest that neuromodulatory transmitters can modulate the excitability of cortical neurons, enhance the signal-to-noise ratio of cortical responses, and modify the threshold for activity-dependent synaptic modifications. Synaptic transmissions of these neuromodulatory transmitters are mediated via numerous subtype receptors, which are linked to multiple signal transduction mechanisms. Among the neuromodulatory transmitter receptor subtypes, cholinergic M(1), noradrenergic beta(1) and serotonergic 5-HT(2C) receptors appear to be more important than other receptor subtypes for cortical plasticity. In general, the contribution of neuromodulatory transmitter systems to cortical plasticity may be made through a facilitation of NMDA receptor-gated processes.
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Affiliation(s)
- Q Gu
- Brain Research Center, and Department of Ophthalmology, University of British Columbia, and Vancouver Hospital and Health Sciences Center, 2550 Willow Street, Vancouver, BC, Canada V5Z 3N9.
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74
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Hirokawa Y, Harada H, Yoshikawa T, Yoshida N, Kato S. Synthesis and structure-activity relationships of 4-amino-5-chloro-N-(1,4-dialkylhexahydro-1,4-diazepin-6-yl)-2-methoxybenzamide derivatives, novel and potent serotonin 5-HT3 and dopamine D2 receptors dual antagonist. Chem Pharm Bull (Tokyo) 2002; 50:941-59. [PMID: 12130853 DOI: 10.1248/cpb.50.941] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In search of a dopamine D2 and serotonin 5-HT3 receptors dual antagonist as a potential broad antiemetic agent, a number of benzamides were prepared from 4-amino-5-chloro-2-methoxybenzoic acid derivatives and 6-amino-1,4-dialkylhexahydro-1,4-diazepines and evaluated for their binding affinity for the dopamine D2 and the serotonin 5-HT3 receptors using rat brain synaptic and rat cortical membranes, respectively. From the results of both in vitro receptor binding and in vivo biological assays for the dopamine D2 receptor, 1-ethyl-4-methylhexahydro-1,4-diazepine ring was selected as an optimum amine moiety. Introduction of one methyl group on the nitrogen atom at the 4-position and/or modification of the substituent at the 5-position of the 4-amino-5-chloro-2-methoxybenzoyl moiety caused a marked increase in the dopamine D2 receptor binding affinity along with a potent 5-HT3 receptor binding affinity. Among the compounds, 5-chloro-N-(1-ethyl-4-methylhexahydro-1,4-diazepin-6-yl)-2-methoxy-4-methylaminobenzamide (82), 5-bromo (110), and 5-iodo (112) analogues exhibited a much higher affinity for the dopamine D2 receptor than that of metoclopramide (IC50=17.5-61.0 nM vs. 483 nM). In particular, 82 showed a potent antagonistic activity for both receptors in vivo tests. Optical resolution of the racemate 82 brought about a dramatic change in the pharmacological profile with the (R)-enantiomer exhibiting a strong affinity for both the dopamine D2 and the 5-HT3 receptors, while the corresponding (S)-enantiomer had a potent and selective serotonin 5-HT3 receptor binding affinity.
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Affiliation(s)
- Yoshimi Hirokawa
- Medicinal Chemistry Group, Chemistry Research Laboratories, Dainippon Pharmaceutical Co. Ltd, Suita, Osaka, Japan.
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75
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Hasegawa M, Sasaki T, Sadakane K, Tabuchi M, Takeda Y, Kimura M, Fujii Y. Studies for the emetic mechanisms of ipecac syrup (TJN-119) and its active components in ferrets: involvement of 5-hydroxytryptamine receptors. JAPANESE JOURNAL OF PHARMACOLOGY 2002; 89:113-9. [PMID: 12120752 DOI: 10.1254/jjp.89.113] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Ipecac syrup, prepared from a galentical ipecac, contains the nauseant alkaloids cephaeline and emetine. The involvement of receptors and serotonin- and dopamine-metabolizing enzymes in the emesis induced by ipecac syrup and these components was investigated. 1) In ferrets, the selective 5-HT3-receptor antagonist ondansetron (0.5 mg/kg, p.o.) prevented each emesis induced by TJN-119 (0.5 mL/kg, p.o.), cephaeline (0.5 mg/kg, p.o.) and emetine (5.0 mg/kg, p.o.), but the intraperitoneal administration of the selective dopamine D2-receptor antagonist sulpiride failed to significantly suppress the TJN-119, cephaeline and emetine-induced emesis at a dose of 0.1 mg/kg that blocked apomorphine-induced emesis. 2) In the receptor binding assays, cephaeline and emetine had a distinct affinity to 5-HT4 receptor, but no or weak affinity to 5-HT1A, 5-HT3, nicotine, M3, beta1, NK1, and D2 receptors. 3) Cephaeline and emetine did not affect activities of metabolic enzymes of 5-HT and dopamine (MAO-A, MAO-B, tryptophan 5-hydroxylase and tyrosine hydroxylase) in vitro. These results suggest that 5-HT3 receptor plays an important role in the emetic action of TJN-119, cephaeline and emetine, and the 5-HT4 receptor may be involved in their mechanisms.
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76
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Kikuchi C, Ando T, Watanabe T, Nagaso H, Okuno M, Hiranuma T, Koyama M. 2a-[4-(Tetrahydropyridoindol-2-yl)butyl]tetrahydrobenzindole derivatives: new selective antagonists of the 5-hydroxytryptamine7 receptor. J Med Chem 2002; 45:2197-206. [PMID: 12014957 DOI: 10.1021/jm0104264] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of tetrahydrobenzindoles was prepared, and the affinity of these compounds for the 5-hydroxytryptamine7 (5-HT7) receptor and other receptors was evaluated. Most of the compounds showed high affinity for the 5-HT7 receptor, and 2a-[4-(tetrahydropyridoindol-2-yl)butyl]tetrahydrobenzindole derivatives (26a-j) exhibited high selectivity for this receptor. The nature of the substituent at the 9-position of the tetrahydropyridindole ring affected the affinity for the 5-HT7 receptor, and the 9-carbamoyl moiety afforded increased selectivity. Compound 26j exhibited high affinity for the 5-HT7 receptor, with at least 280-fold selectivity over the 5-HT2 receptor. In a functional model of 5-HT7 receptor activation, this compound was confirmed to have 5-HT7 receptor antagonist activity. It should be a useful tool for clarifying the biological role of the 5-HT7 receptor.
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Affiliation(s)
- Chika Kikuchi
- Pharmaceutical Research Center, Meiji Seika Kaisha Ltd., 760 Morooka-cho, Kohoku-ku, Yokohama 222-8567, Japan
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77
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Fujii W, Hori H, Yokoo Y, Suwa Y, Nukaya H, Taniyama K. Beer Congener Stimulates Gastrointestinal Motility Via the Muscarinic Acetylcholine Receptors. Alcohol Clin Exp Res 2002. [DOI: 10.1111/j.1530-0277.2002.tb02590.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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78
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De Deurwaerdère P, Cervo L, Stinus L, Spampinato U. Central 5-HT(4) receptors and dopamine-dependent motor behaviors: searching for a functional role. Pharmacol Biochem Behav 2002; 71:627-33. [PMID: 11888554 DOI: 10.1016/s0091-3057(01)00703-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this study, we evaluated the role of central 5-HT(4) receptors in the control of motor behaviors related to change of nigrostriatal dopamine (DA) transmission, namely, stereotyped behavior and catalepsy in rats. Indeed, given that 5-HT(4) receptors indirectly modulate nigrostriatal DA neuron activity, we hypothesized that these receptors would regulate nigrostriatal DA transmission in the basal ganglia, and consequently, associated motor responses. Stereotypy was induced either by an acute administration of apomorphine (0.3 and 1.5 mg/kg sc), or by a single morphine administration (15 mg/kg sc) in chronically morphine-treated (15 mg/kg sc, twice daily for 10 days) rats. Catalepsy was induced by the typical neuroleptic haloperidol (HAL; 1 mg/kg sc). The selective 5-HT(4) antagonist, GR 125487 (1 mg/kg ip), modified neither apomorphine- nor morphine-induced stereotypy. HAL-induced catalepsy, while reduced by the systemic administration of the 5-HT(1A) agonist 8-OH-DPAT (0.1 mg/kg sc), was insensitive to GR 125487, systemically (1, 3, 10 mg/kg ip) or locally (20 and 40 nmol/20 microl) administered into the third ventricle. Also, HAL-induced catalepsy was not affected by the selective 5-HT(4) antagonist GR 113808 (3 mg/kg ip). The obtained results indicate that 5-HT(4) receptor antagonism does not modulate motor behaviors related to change of striatal DA transmission.
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Affiliation(s)
- Philippe De Deurwaerdère
- Laboratoire Neuropsychobiologie des Désadaptations, UMR-CNRS 5541, Université Victor Segalen Bordeaux 2, B.P. 31, 146 rue Léo-Saignat, 33077 Cedex, Bordeaux, France
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79
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Iriepa I, Villasante FJ, Gálvez E, Labeaga L, Innerarity A, Orjales A. Synthesis and pharmacology of isoquinuclidine derivatives as 5-HT(3) ligands. Bioorg Med Chem Lett 2002; 12:189-92. [PMID: 11755351 DOI: 10.1016/s0960-894x(01)00693-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A series of 4-amino-5-chloro-2-methoxybenzoates and benzamides containing the 5- and 6-isoquinuclidinyl system was synthesised and evaluated for binding to 5-HT(3), 5-HT(4) and D(2) receptors. In general, the isoquinuclidine derivatives at the 5-position have shown to be more potent as 5-HT(3) ligands but they also possess 5-HT(4) and D(2) properties. However, the results show that the derivatives at the 6-position afforded the most promising compounds in terms of both receptor affinity and selectivity.
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Affiliation(s)
- Isabel Iriepa
- Departamento de Química Orgánica, Universidad de Alcalá, Ctra. Madrid-Barcelona Km. 33,600, 28871 Alcalá de Henares, Madrid, Spain.
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80
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Tazawa S, Masuda N, Koizumi T, Kitazawa M, Nakane T, Miyata H. KDR-5169, a new gastrointestinal prokinetic agent, enhances gastric contractile and emptying activities in dogs and rats. Eur J Pharmacol 2002; 434:169-76. [PMID: 11779580 DOI: 10.1016/s0014-2999(01)01543-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
KDR-5169, 4-amino-5-chloro-N-[1-(3-fluoro-4-methoxybenzyl)piperidin-4-yl]-2-(2-hydroxyethoxy)benzamide hydrochloride dihydrate, is a new prokinetic with a dual action, i.e., stimulation of the 5-HT4 receptor and antagonism of the dopamine D2 receptor. In this study, we determined in vitro activities of KDR-5169 towards both receptors and demonstrated the effect of the compound on gastrointestinal motor activity in conscious dogs and rats. In dogs, intravenous KDR-5169 stimulated upper gastrointestinal motility in the fasting state and also eliminated the depressive effect of 3,4-dihydroxyphenylalanine (L-DOPA) on this motility in the postprandial state. The effect of KDR-5169 on gastric emptying was further characterized by the use of three rat gastroparesis models (dopamine D2 receptor agonist (quinpirol)-, abdominal surgery-, or combined-situation-induced). Domperidone (a dopamine D2 receptor antagonist) was effective in the quinpirol-delay and combination-delay models, and cisapride and mosapride (5-HT4 receptor agonists) were effective in the surgery-delay model. Only KDR-5169 eliminated the delay of gastric emptying in all three models. In addition, KDR-5169 accelerated emptying to above the normal level in the combination-delay model. These results suggest that KDR-5169 would be effective in various types of gastric ileus caused by different mechanisms.
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Affiliation(s)
- Shigeki Tazawa
- Discovery Research Laboratories, Kissei Pharmaceutical Co. Ltd., 4365-1 Kashiwabara, Hotaka, Minamiazumi, Nagano, 399-8304, Japan.
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81
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Pindon A, van Hecke G, van Gompel P, Lesage AS, Leysen JE, Jurzak M. Differences in signal transduction of two 5-HT4 receptor splice variants: compound specificity and dual coupling with Galphas- and Galphai/o-proteins. Mol Pharmacol 2002; 61:85-96. [PMID: 11752209 DOI: 10.1124/mol.61.1.85] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study documents differences in ligand binding and signal transduction properties between the human (h) 5-hydroxytryptamine (5-HT)4a and h5-HT4b receptor splice variants stably expressed in human embryonic kidney 293 cells. The fraction of the [3H]5-HT high-affinity site relative to the whole receptor population measured with [3H]GR113808 was higher for the h5-HT4a isoform (around 0.4) than for the 5-HT4b isoform (around 0.2) and was independent of the level of expression. The potency and efficacy of reference compounds tested for the cAMP response differed slightly but significantly between both variants. Most remarkably, 5-methoxytryptamine and prucalopride were found more potent on the 5-HT4b variant, whereas SDZ-HTF 919 and SB204070 were more potent on the 5-HT(4a) variant. Guanosine-5'-O-(3-[35S]thio)triphosphate binding on membranes and cAMP assays in whole cells revealed that only the h5-HT4b isoform coupled to Galphai/o-proteins in addition to its well-documented Galphas coupling. In contrast, the h5-HT4a receptor coupled only to Galphas-proteins, however, was able to trigger an increase in the intracellular calcium concentration ([Ca(2+)]i). The observed [Ca(2+)]i increase did not occur through inositol phosphate formation and was not sensitive to Bordetella pertussis toxin, forskolin, or 3-isobutyl-1-methylxanthine (pre)treatment but was due to Ca(2+) influx from the extracellular environment. Interestingly, the Ca(2+) pathway was dependent on high receptor expression levels and was compound-specific, because benzamide-like compounds triggered two to three times higher responses than indoleamines. Taken together, these data provide the first evidence for fine functional differences between C-terminal splice variants of the h5-HT4 receptor, which may contribute to a better understanding of the functional diversity of this receptor class.
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Affiliation(s)
- Armelle Pindon
- Department of Receptor Pharmacology, Janssen Research Foundation, B-2340 Beerse, Belgium
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82
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Lamirault L, Simon H. Enhancement of place and object recognition memory in young adult and old rats by RS 67333, a partial agonist of 5-HT4 receptors. Neuropharmacology 2001; 41:844-53. [PMID: 11684148 DOI: 10.1016/s0028-3908(01)00123-x] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
There is recent evidence that activation of central 5-hydroxytryptamine (5-HT)4 receptors enhances cognitive processes such as learning and memory. In the present study, we assessed the effects of a selective 5-HT4 receptors agonist, RS 67333 [1(4-amino-5-chloro-2-methoxyphenyl)-3-(1-n-butyl-4-piperidinyl)-1-propanone], in a two-trial recognition task designed to test place or object recognition memory.RS 67333 was injected in young adult (0.0001, 0.01, 1 mg/kg, i.p.) and old (0.0001, 0.01, 1, 10 mg/kg, i.p.) rats before the acquisition phase, immediately after it, or before the retrieval phase, to determine the stage of information processing affected by the compound. When injected before the acquisition phase, RS 67333 (1 mg/kg) enhanced place and object recognition in young adult rats. In old rats, RS 67333 (10 mg/kg) improved place recognition when injected before the acquisition phase, and object recognition when injected before the acquisition or in the consolidation phase of information processing. The beneficial effects of RS 67333 were abolished by prior treatment with a selective 5-HT4 receptors antagonist, GR 125487 [(1-[2-[methyl sulphonyl)-amino]ethyl]-4-piperidinyl-methyl 5-fluoro-2-methoxy-1H-indole-3-carboxylate); 10 mg/kg, i.p.]. These results support the view that selective 5-HT4 receptors agonists may be of value in the treatment of cognitive disorders related to normal aging or neurodegenerative conditions such as Alzheimer's disease.
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Affiliation(s)
- L Lamirault
- Laboratoire de Neuropsychobiologie des Désadaptations, CNRS UMR 5541, Université Victor Segalen Bordeaux 2, BP 31, 146, rue Léo Saignat, 33076 Cedex, Bordeaux, France.
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83
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Thiriet N, Zwiller J, Ali SF. Induction of the immediate early genes egr-1 and c-fos by methamphetamine in mouse brain. Brain Res 2001; 919:31-40. [PMID: 11689160 DOI: 10.1016/s0006-8993(01)02991-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Methamphetamine (METH) is one of the most commonly abused psychostimulant, and is known to induce dopaminergic neurotoxicity by generating oxidative stress and free radicals. In the present study we investigated the effects of METH on egr-1 and c-fos immediate early gene induction in different regions of mouse brain, at different doses and different time courses. We also measured the tissue levels of monoamines in order to correlate their changes with gene expression. A single injection of METH (40 mg/kg) significantly increased egr-1 and c-fos mRNA expression within 30 min in frontal cortex, nucleus accumbens, caudate putamen, septum and CA1 region of hippocampus. Time course studies showed that in most cases, both genes were expressed within 30 min and decreased after 60 min. METH produced a significant decrease in striatal dopamine level, reaching a very low level after 24 h. Striatal serotonin level significantly increased and returned to control levels after 2 h. These data show that METH induced egr-1 and c-fos mRNA expression in selective brain areas, which correlated with an alteration in monoamines.
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Affiliation(s)
- N Thiriet
- INSERM U338, Centre de Neurochimie, 5 rue Blaise Pascal, 67084, Strasbourg, France
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84
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López-Rodríguez ML, Murcia M, Benhamú B, Viso A, Campillo M, Pardo L. 3-D-QSAR/CoMFA and recognition models of benzimidazole derivatives at the 5-HT(4) receptor. Bioorg Med Chem Lett 2001; 11:2807-11. [PMID: 11597405 DOI: 10.1016/s0960-894x(01)00517-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
3-D-QSAR/CoMFA methodology and computational simulation of ligand recognition have been successfully applied to explain the binding affinities of a series of benzimidazole derivatives 1-24 acting at serotonin 5-HT(4)Rs. Both derived computational models have facilitated the identification of the structural elements of the ligands that are key to high 5-HT(4)R affinity. The results provide the tools for predicting the affinity of related compounds, and for guiding the design and synthesis of new ligands with predetermined affinities and selectivity.
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Affiliation(s)
- M L López-Rodríguez
- Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense, E-28040 Madrid, Spain.
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85
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López-Rodríguez ML, Murcia M, Benhamú B, Olivella M, Campillo M, Pardo L. Computational model of the complex between GR113808 and the 5-HT4 receptor guided by site-directed mutagenesis and the crystal structure of rhodopsin. J Comput Aided Mol Des 2001; 15:1025-33. [PMID: 11989623 DOI: 10.1023/a:1014895611874] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A computational model of the transmembrane domain of the human 5-HT4 receptorcomplexed with the GR113808 antagonist was constructed from the crystal structure of rhodopsin and the putative residues of the ligand-binding site, experimentally determined by site-directed mutagenesis. The recognition mode of GR113808 consist of: (i) the ionic interaction between the protonated amine and Asp3.32; (ii) the hydrogen bond between the carbonylic oxygen and Ser5.43; (iii) the hydrogen bond between the ether oxygen and Asn6.55; (iv) the hydrogen bond between the C-H groups adjacent to the protonated piperidine nitrogen and the pi electrons of Phe6.51; and (v) the pi-sigma aromatic-aromatic interaction between the indole ring and Phe6.52. This computational model offers structural indications about the role of Asp3.32, Ser5.43, Phe6.51, Phe6.52, and Asn6.55 in the experimental binding affinities. Asp3.32Asn mutation does not affect the binding of GR113808 because the loss of binding affinity from an ion pair to a charged hydrogen bond is compensated by the larger energetical penalty of Asp to disrupt its side chain environment in the ligand-free form, and the larger interaction between Phe6.51 and the piperidine ring of the ligand in the mutant receptor. In the Phe6.52Val mutant the indole ring of the ligand replaces the interaction with Phe6.52 by a similarly intense interaction with Tyr5.38, with no significant effect in the binding of GR113808. The mutation of Asn6.55 to Leu replaces the hydrogen bond of the ether oxygen of the ligand from Asn6.55 to Cys5.42, with a decrease of binding affinity that approximately equals the free energy difference between the SH...O and NH...O hydrogen bonds. Because these residues are also present in the other members of the neurotransmitter family of G protein-coupled receptors, these findings will also serve for our understanding of the binding of related ligands to their cognate receptors.
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Affiliation(s)
- M L López-Rodríguez
- Unitat de Bioestadística, Facultat de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
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86
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Coelho AM, Jacob L, Fioramonti J, Bueno L. Rectal antinociceptive properties of alverine citrate are linked to antagonism at the 5-HT1A receptor subtype. J Pharm Pharmacol 2001; 53:1419-26. [PMID: 11697552 DOI: 10.1211/0022357011777783] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Serotonin (5-HT) is considered as a major mediator causing hyperalgesia and is involved in inflammatory reactions and irritable bowel syndrome. Alverine citrate may possess visceral antinociceptive properties in a rat model of rectal distension-induced abdominal contractions. This study was designed to evaluate the pharmacological properties of alverine citrate in a rat model of rectal hyperalgesia induced by 5-HTP (5-HT precursor) and by a selective 5-HT1A agonist (8-OH-DPAT) and to compare this activity with a reference 5-HT1A antagonist (WAY 100635). At 4 h after their administration, 5-HTP and 8-OH-DPAT increased the number of abdominal contractions in response to rectal distension at the lowest volume of distension (0.4 mL). When injected intraperitoneally before 8-OH-DPAT and 5-HTP, WAY 100635 (1 mg kg(-1)) blocked their nociceptive effect, but also reduced the response to the highest volume of distension (1.6 mL). Similarly, when injected intraperitoneally, alverine citrate (20 mg kg(-1)) suppressed the effect of 5-HTP, but not that of 8-OH-DPAT. However, when injected intracerebroventricularly (75 microg/rat) alverine citrate reduced 8-OH-DPAT-induced enhancement of rectal distension-induced abdominal contractions. In-vitro binding studies revealed that alverine citrate had a high affinity for 5-HT1A receptors and a weak affinity for 5-HT3 and 5-HT4 subtypes. These results suggest that 5-HTP-induced rectal hypersensitivity involves 5-TH1A receptors and that alverine citrate acts as a selective antagonist at the 5-HT1A receptor subtype to block both 5-HTP and 8-OH-DPAT-induced rectal hypersensitivity.
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Affiliation(s)
- A M Coelho
- Department of Pharmacology, Institut National de la Recherche Agronomique, Toulouse, France
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87
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López-Rodrı́guez ML, Benhamú B, Viso A, Murcia M, Pardo L. Study of the bioactive conformation of novel 5-HT4 receptor ligands: influence of an intramolecular hydrogen bond. Tetrahedron 2001. [DOI: 10.1016/s0040-4020(01)00621-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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88
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Castro L, Varjão B, Silva I, Duque B, Batista A, Santana R, Luz P, Rocha MA, Fregoneze JB, De Castro-e-Silva E. Effect of the intracerebroventricular administration of GR 113808, a selective 5-HT4 antagonist, on water intake during hyperosmolarity and hypovolemia. Braz J Med Biol Res 2001; 34:791-6. [PMID: 11378670 DOI: 10.1590/s0100-879x2001000600015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We demonstrate here that acute third ventricle injections of GR 113808, a highly selective 5-HT4 antagonist, decrease water intake induced by a previous salt load while potentiating drinking elicited by hypovolemia induced by previous subcutaneous administration of polyethylene glycol in male Wistar rats (200 +/- 20 g). At the dose of 160 nmol/rat, third ventricle injections of GR 113808 induced a significant reduction of water intake in salt-loaded animals after 120 min as compared to salt-loaded animals receiving third ventricle injections of saline (salt load + GR = 3.44 +/- 0.41 ml, N = 12; salt load + saline = 5.74 +/- 0.40 ml, N = 9). At the dose of 80 nmol/rat, GR 113808 significantly enhanced water intake in hypovolemic animals after 120 min as compared to hypovolemic animals receiving third ventricle injections of saline (hypovol + GR = 4.01 +/- 0.27 ml, N = 8; hypovol + saline = 2.41 +/- 0.23 ml, N = 12). We suggest that central 5-HT4 receptors may exert a positive drive on water intake due to hyperosmolarity and a negative input on drinking provoked by hypovolemia.
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Affiliation(s)
- L Castro
- Departamento de Fisiologia, Instituto de Ciências da Saúde, Universidade Federal da Bahia, 40110-100 Salvador, BA, Brazil
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89
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Lucas G, Di Matteo V, De Deurwaerdère P, Porras G, Martín-Ruiz R, Artigas F, Esposito E, Spampinato U. Neurochemical and electrophysiological evidence that 5-HT4 receptors exert a state-dependent facilitatory control in vivo on nigrostriatal, but not mesoaccumbal, dopaminergic function. Eur J Neurosci 2001; 13:889-98. [PMID: 11264661 DOI: 10.1046/j.0953-816x.2000.01453.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In this study we investigated, using in vivo microdialysis and single unit recordings, the role of serotonin4 (5-HT4) receptors in the control of nigrostriatal and mesoaccumbal dopaminergic (DA) pathway activity. In freely moving rats, the 5-HT4 antagonist GR 125487 (1 mg/kg, i.p.), without effect on its own, significantly reduced the enhancement of striatal DA outflow induced by 0.01 (-35%) and 0.1 (-66%), but not 1 mg/kg, s.c. haloperidol (HAL). Intrastriatal infusion of GR 125487 (1 microM) had no influence on basal DA outflow, but attenuated (-49%) the effect of 0.01 mg/kg HAL. Systemic administration of GR 125487 modified neither basal nor 0.01 mg/kg HAL-stimulated accumbal DA outflow. In halothane-anaesthetized rats, 1 or 10 mg/kg GR 125487, without effect by itself, failed to modify the changes in accumbal and striatal DA outflow elicited by electrical stimulation (300 microA, 1 ms, 20 Hz, 15 min) of the dorsal raphe nucleus. Finally, GR 125487 (444 microg/kg, i.v.), whilst not affecting basal firing of DA neurons within either the substantia nigra or the ventral tegmental area, reduced HAL-stimulated (1--300 microg/kg, i.v.) impulse flow of nigrostriatal DA neurons only. These results indicate that 5-HT4 receptors exert a facilitatory control on both striatal DA release and nigral DA neuron impulse flow only when nigrostriatal DA transmission is under activated conditions. Furthermore, they indicate that the striatum constitutes a major site for the expression of the control exerted by 5-HT4 receptors on DA release. In contrast, 5-HT4 receptors have no influence on mesoaccumbal DA activity in either basal or activated conditions.
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Affiliation(s)
- G Lucas
- Laboratoire Neuropsychobiologie des Désadaptations, UMR-CNRS 5541, Université Victor Segalen Bordeaux 2, B.P. 31, 146 rue Léo-Saignat, 33077 Bordeaux Cedex, France
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90
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Modica M, Santagati M, Guccione S, Russo F, Cagnotto A, Goegan M, Mennini T. Design, synthesis and binding properties of novel and selective 5-HT3 and 5-HT4 receptor ligands. Eur J Med Chem 2001; 36:287-301. [PMID: 11337106 DOI: 10.1016/s0223-5234(01)01216-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This work reports the synthesis and the binding tests on the 5-HT3 and 5-HT4 receptors of new thienopyrimidopiperazine and piperazinylacylaminodimethylthiophene derivatives, in order to identify potent and selective ligands for each receptor. The 3-amino-2-(4-benzyl-1-piperazinyl)-5,6-dimethyl-thieno[2,3-d]pyrimidin-4(3H)-one derivative 28 showed the highest affinity and selectivity for the 5-HT3 over the 5-HT4 receptor (5-HT3 Ki=3.92 nM, 5-HT4 not active), whereas the 2-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butanoylamino]-4,5-dimethyl-3-thiophenecarboxylic acid ethyl ester (41) showed the highest affinity and selectivity for the 5-HT4 over the 5-HT3 receptor (5-HT4 Ki=81.3 nM, 5-HT3 not active). Conformational analyses were carried out on the compounds of the piperazinylacylaminodimethylthiophene series (39-42) taking compound 41 as the template.
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Affiliation(s)
- M Modica
- Dipartimento di Scienze Farmaceutiche, viale Andrea Doria, 6, Ed. 2 Città Universitaria, I-95125, Catania, Italy
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91
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López-Rodríguez ML, Morcillo MJ, Fernández E, Porras E, Orensanz L, Beneytez ME, Manzanares J, Fuentes JA. Synthesis and structure-activity relationships of a new model of arylpiperazines. 5. Study of the physicochemical influence of the pharmacophore on 5-HT(1a)/alpha(1)-adrenergic receptor affinity: synthesis of a new derivative with mixed 5-HT(1a)/d(2) antagonist properties. J Med Chem 2001; 44:186-97. [PMID: 11170628 DOI: 10.1021/jm000929u] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this paper we have designed and synthesized a test series of 32 amide arylpiperazine derivatives VI in order to gain insight into the physicochemical influence of the pharmacophores of 5-HT(1A) and alpha(1)-adrenergic receptors. The training set was designed applying a fractional factorial design using six physicochemical descriptors. The amide moiety is a bicyclohydantoin or a diketopiperazine (X = -(CH(2))(3)-, -(CH(2))(4)-; m = 0, 1), the spacer length is 3 or 4 methylene units, which are the optimum values for both receptors, and the aromatic substituent R occupies the ortho- or meta-position and has been selected from a database of 387 substituents using the EDISFAR program. The 5-HT(1A) and alpha(1)-adrenergic receptor binding affinities of synthesized compounds VI (1-32) have been determined. This data set has been used to derive classical quantitative structure-activity relationships (QSAR) and neural networks models for both receptors (following paper). A comparison of these models gives information for the design of the new ligand EF-7412 (46) (5-HT(1A): K(i) = 27 nM; alpha(1): K(i) > 1000 nM). This derivative displays affinity for the dopamine D(2) receptor (K(i) = 22 nM) and is selective versus all other receptors examined (5-HT(2A), 5-HT(3), 5-HT(4) and Bz; K(i) > 1000 nM). EF-7412 (46) acts as an antagonist in vivo in pre- and postsynaptic 5-HT(1A) receptor sites and as an antagonist in the dopamine D(2) receptor. Thus, EF-7412 (46) is a derivative with mixed 5-HT(1A)/D(2) antagonist properties and this derivative could be useful as a pharmacological tool.
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Affiliation(s)
- M L López-Rodríguez
- Departamento de Química Orgánica I, Facultad de Ciencias Químicas, and Departamento de Farmacología, Facultad de Farmacia, Universidad Complutense, 28040 Madrid, Spain.
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92
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Horikoshi K, Yokoyama T, Kishibayashi N, Ohmori K, Ishii A, Karasawa A. Possible involvement of 5-HT4 receptors, in addition to 5-HT3 receptors, in the emesis induced by high-dose cisplatin in Suncus murinus. JAPANESE JOURNAL OF PHARMACOLOGY 2001; 85:70-4. [PMID: 11243577 DOI: 10.1254/jjp.85.70] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
To clarify the mechanism for the severe emesis concomitant with intensive chemotherapy, we investigated the effects of 5-HT3- and 5-HT4-receptor antagonists on the emesis induced by the high-dose of cisplatin in Suncus murinus. The emesis induced by 50 mg/kg of cisplatin was reduced by the oral pretreatment with tropisetron, which is known as a 5-HT3- and 5-HT4-receptor dual antagonist in vitro, with the ID50 value of 0.52 mg/kg. On the contrary, granisetron, a selective 5-HT3-receptor antagonist, did not markedly inhibit the emesis at up to 30 mg/kg. Moreover, GR125487, a selective 5-HT4-receptor antagonist, did not inhibit the emesis. However, co-administration of GR125487 and granisetron significantly reduced the number of emetic episodes. The study of the co-administration of GR125487 with tropisetron showed that GR125487 did not further enhance the inhibitory effect of tropisetron alone, suggesting that the anti-emetic effect of tropisetron is mediated via the blockade of both 5-HT3 and 5-HT4 receptors. These results suggest that both the 5-HT3 and 5-HT4 receptors are involved in the emesis induced by the high-dose of cisplatin in Suncus murinus.
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Affiliation(s)
- K Horikoshi
- Drug Development Research Laboratories, Pharmaceutical Research Institute, Kyowa Hakko Kogyo Co., Ltd., Sunto-gun, Shizuoka, Japan.
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93
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Modica M, Santagati M, Guccione S, Russo F, Cagnotto A, Goegan M, Mennini T. Design, synthesis and binding properties of novel and selective 5-HT(3) and 5-HT(4) receptor ligands. Eur J Med Chem 2000; 35:1065-79. [PMID: 11248405 DOI: 10.1016/s0223-5234(00)01187-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This work reports the synthesis and the binding tests on the 5-HT(3) and 5-HT(4) receptors of new thienopyrimidopiperazine and piperazinylacylaminodimethylthiophene derivatives, in order to identify potent and selective ligands for each receptor. The compound with higher affinity and selectivity for the 5-HT(3) over the 5-HT(4) receptor was the 3-amino-2-(4-benzyl-1-piperazinyl)-5,6-dimethyl-thieno[2,3-d]pyrimidin-4(3H)-one 28 (5-HT(3) K(i)=3.92 nM, 5-HT(4) not active), the compound with higher affinity and selectivity for the 5-HT(4) over the 5-HT(3) receptor was the 2-[4-[4-(2-pyrimidinyl)-1-piperazinyl]butanoylamino]-4,5-dimethyl-3-thiophenecarboxylic acid ethyl ester 41 (5-HT(4) K(i)=81.3 nM, 5-HT(3) not active). Conformational analyses were carried out on the compounds of the piperazinylacylaminodimethylthiophene series (39-42) taking compound 41 as the template.
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Affiliation(s)
- M Modica
- Dipartimento di Scienze Farmaceutiche, Università di Catania, viale A. Doria 6, 95125, Catania, Italy
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94
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Diouf O, Depreux P, Chavatte P, Poupaert JH. Synthesis and preliminary pharmacological results on new naphthalene derivatives as 5-HT(4) receptor ligands. Eur J Med Chem 2000; 35:699-706. [PMID: 10960185 DOI: 10.1016/s0223-5234(00)00163-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The indole derivative GR 113808 is currently used as the reference ligand for labelling the 5-HT(4) serotoninergic receptors. Previous works in our laboratories established the bioisosteric equivalency of the indole heterocycle and naphthalene in a series of melatonin receptor ligands. Based on this knowledge we designed new analogues of GR 113808 by introducing two bioisosteric modifications: firstly, the indole ring was replaced by a naphthalene one and secondly, the ester linkage was replaced by an amide group. Compound 8 emerged within this novel series as it displayed high and selective affinity at 5-HT(4) receptors (Ki 5-HT(4) = 6 nM, Ki 5-HT(3) = 100 nM, Ki values at other 5-HT receptors were higher than 1000 nM). Compound 8 is currently undergoing further pharmacological evaluation.
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Affiliation(s)
- O Diouf
- Institut de chimie pharmaceutique Albert Lespagnol, 3, rue du Professeur Laguesse, BP 83, 59006 cedex, Lille, France
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95
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Bourdon DM, Camden JM, Landon LA, Levy FO, Turner JT. Identification of the adenylyl cyclase-activating 5-hydroxytryptamine receptor subtypes expressed in the rat submandibular gland. Br J Pharmacol 2000; 130:104-8. [PMID: 10781004 PMCID: PMC1572050 DOI: 10.1038/sj.bjp.0703303] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1. Serotonin (5-hydroxytryptamine, 5-HT) has been shown to increase cyclic AMP production in dispersed cell aggregates from the major salivary glands of the rat. The goal of the present study was to identify the 5-HT receptor subtypes that mediate these effects in rat submandibular glands (SMG). 2. Among the 5-HT receptor subtypes identified in the rat, 5-HT(4(a,b)), 5-HT(6) and 5-HT(7(a,b,c)) activate adenylyl cyclase (AC). We used subtype specific primers to screen rat SMG by reverse transcription-PCR. Results indicate the presence of mRNA for 5-HT(4(b)) and 5-HT(7(a)) but not for 5-HT(4(a)), 5-HT(6) and 5-HT(7(b,c)). 3. In dispersed SMG cells, 5-carboxyamidotryptamine (5-CT), a 5-HT(7) receptor agonist, stimulated cyclic AMP synthesis with higher potency (EC(50)=27+/-5 nM) but lower efficacy than 5-HT, suggesting a 5-HT(7) component and an additional component in the response to 5-HT. The 5-HT(7) contribution was further supported by antagonism of the 5-CT effect by metergoline, a 5-HT(7) antagonist, which exhibited an affinity (K(i)=50 nM) similar to that obtained at the cloned 5-HT(7) receptor. 4. In the presence of a maximally effective concentration of 5-CT, 5-HT produced an additional increase in cyclic AMP production that was inhibited by the 5-HT(4) receptor antagonist, GR113808, suggesting that the second component of cyclic AMP production is mediated by 5-HT(4) receptors. 5. These findings indicate the presence in rat SMG of both 5-HT(4(b)) and 5-HT(7(a)) receptors positively coupled to AC.
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Affiliation(s)
- D M Bourdon
- Department of Pharmacology, School of Medicine, University of Missouri, M561 HSC, One Hospital Drive, Columbia, Missouri, MO 65212, U.S.A
| | - J M Camden
- Department of Pharmacology, School of Medicine, University of Missouri, M561 HSC, One Hospital Drive, Columbia, Missouri, MO 65212, U.S.A
| | - L A Landon
- Department of Pharmacology, School of Medicine, University of Missouri, M561 HSC, One Hospital Drive, Columbia, Missouri, MO 65212, U.S.A
| | - F O Levy
- MSD Cardiovascular Research Center and Institute for Surgical Research, University of Oslo, The National Hospital–Rikshospitalet, N-0027, Oslo, Norway
| | - J T Turner
- Department of Pharmacology, School of Medicine, University of Missouri, M561 HSC, One Hospital Drive, Columbia, Missouri, MO 65212, U.S.A
- Author for correspondence:
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96
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Prins NH, Shankley NP, Welsh NJ, Briejer MR, Lefebvre RA, Akkermans LM, Schuurkes JA. An improved in vitro bioassay for the study of 5-HT(4) receptors in the human isolated large intestinal circular muscle. Br J Pharmacol 2000; 129:1601-8. [PMID: 10780964 PMCID: PMC1572010 DOI: 10.1038/sj.bjp.0703254] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Recently, it was demonstrated that 5-HT induces relaxation of human colon circular muscle through activation of 5-HT(4) receptors and 5-HT(7) receptors. The aim of the current study was to develop a new in vitro bioassay of human colon that would facilitate the pharmacological analysis of 5-HT responses mediated solely by 5-HT(4) receptors. Contracting circular muscle strips with KCl (80 mM) yielded a stable contractile tension and, in contrast to muscarinic cholinoceptor agonists and histamine, a profound reduction of spontaneous contractility. This allowed the establishment of reproducible, fully-defined, agonist concentration-response curves by cumulative dosing. Under these conditions, 5-HT induced a concentration-dependent relaxation (pEC(50) 7.31, Hill slope 0.91). Neither methysergide (10 microM) nor granisetron (1 microM) affected the 5-HT-induced relaxation, suggesting that 5-HT(1), 5-HT(2), 5-HT(3), 5-ht(5), 5-HT(6) or 5-HT(7) receptors are not involved. The lack of effect of tetrodotoxin (0.3 microM) indicated a direct effect of 5-HT on the smooth muscle. The selective 5-HT(4) receptor antagonists GR 113808, GR 125487 and RS 39604 competitively antagonized the 5-HT-induced relaxation (pK(B) 9.43, 10.12 and 8.53, respectively). SB 204070 (1 nM) produced a rightward shift (pA(2) 10.34) and depression of the 5-HT curve. These affinity estimates are similar to those previously reported for 5-HT(4) receptors. The selective 5-HT(4) receptor agonists, prucalopride and R076186, induced relaxations (pEC(50) 7.50 and 7.57, respectively), that were blocked by GR 113808 (3 nM), yielding pA(2) estimates of 9.31 and 9.21, respectively. To summarise, in KCl (80 mM)-contracted muscle strips, 5-HT induces relaxation through activation of a homogeneous smooth muscle 5-HT(4) receptor population. This new bioassay allows the focused, pharmacological characterization of human colonic 5-HT(4) receptors in vitro.
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Affiliation(s)
- N H Prins
- Department of Gastrointestinal Pharmacology, Janssen Research Foundation, Beerse, Belgium.
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97
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Bender E, Pindon A, van Oers I, Zhang YB, Gommeren W, Verhasselt P, Jurzak M, Leysen J, Luyten W. Structure of the human serotonin 5-HT4 receptor gene and cloning of a novel 5-HT4 splice variant. J Neurochem 2000; 74:478-89. [PMID: 10646498 DOI: 10.1046/j.1471-4159.2000.740478.x] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Several variants of the serotonin 5-HT4 receptor are known to be produced by alternative splicing. To survey the existence and usage of exons in humans, we cloned the human 5-HT4 gene. Based on sequence analysis seven C-terminal variants (a-g) and one internal splice variant (h) were found. We concentrated in this study on the functional characterization of the novel splice variant h, which leads to the insertion of 14 amino acids into the second extracellular loop of the receptor. The h variant was cloned as a splice combination with the C-terminal b variant; therefore, we call this receptor 5-HT4(hb). This novel receptor variant was expressed transiently in COS-7 cells, and its pharmacological profile was compared with those of the previously cloned 5-HT4(a) and 5-HT4(b) isoforms, with the latter being the primary reference for the h variant. In competition binding experiments using reference 5-HT4 ligands, no significant differences were detected. However, the broadly used 5-HT4 antagonist GR113808 discriminated functionally among the receptor variants investigated. As expected, it was an antagonist on the 5-HT4(a) and 5-HT4(b) variant but showed partial agonistic activity on the 5-HT4(hb) variant. These data emphasize the importance of variations introduced by splicing for receptor pharmacology and may help in the understanding of conflicting results seen with 5-HT4 ligands in different model systems.
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Affiliation(s)
- E Bender
- Department of Functional Genomics, Janssen Research Foundation, Beerse, Belgium.
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López-Rodríguez ML, Benhamú B, Morcillo MJ, Tejada ID, Orensanz L, Alfaro MJ, Martín MI. Benzimidazole derivatives. 2. Synthesis and structure-activity relationships of new azabicyclic benzimidazole-4-carboxylic acid derivatives with affinity for serotoninergic 5-HT(3) receptors. J Med Chem 1999; 42:5020-8. [PMID: 10585211 DOI: 10.1021/jm991076c] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new series of azabicyclic benzimidazole-4-carboxamides 2-21 and -carboxylates 22-30 were synthesized and evaluated for binding affinity at serotoninergic 5-HT(3) and 5-HT(4) receptors in the CNS. Most of the synthesized compounds exhibited high or very high affinity for the 5-HT(3) binding site and low to no significant affinity for the 5-HT(4) receptor. SAR observations indicated that a halogen atom at the 6-position and a nitro group at the 7-position of the benzimidazole ring is the best substitution pattern for 5-HT(3) affinity and 5-HT(3)/5-HT(4) selectivity, as well as no substitution in this ring. (S)-(-)-N-(Quinuclidin-3-yl)benzimidazole-4-carboxamides 2, 8, and 14 bound at central 5-HT(3) sites with high affinity (K(i) = 2.6, 0. 13, and 1.7 nM, respectively) and excellent selectivity over serotonin 5-HT(4) and 5-HT(1A) receptors (K(i) > 1000-10000 nM). Furthermore, these new 5-HT(3) receptor ligands were pharmacologically characterized as potent and selective 5-HT(3) antagonists in the isolated guinea pig ileum (pA(2) = 9.6, 9.9, and 9.1, respectively).
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Affiliation(s)
- M L López-Rodríguez
- Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain
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López-Rodríguez ML, Benhamú B, Viso A, Morcillo MJ, Murcia M, Orensanz L, Alfaro MJ, Martín MI. Benzimidazole derivatives. Part 1: Synthesis and structure-activity relationships of new benzimidazole-4-carboxamides and carboxylates as potent and selective 5-HT4 receptor antagonists. Bioorg Med Chem 1999; 7:2271-81. [PMID: 10632037 DOI: 10.1016/s0968-0896(99)00172-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
New benzimidazole-4-carboxamides 1-16 and -carboxylates 17-26 were synthesized and evaluated for binding affinity at serotonergic 5-HT4 and 5-HT3 receptors in the CNS. Most of the synthesized compounds exhibited moderate-to-very high affinity (in many cases subnanomolar) for the 5-HT4 binding site and no significant affinity for the 5-HT3 receptor. SAR observations and structural analyses (molecular modeling, INSIGHT II) indicated that the presence of a voluminous substituent in the basic nitrogen atom of the amino moiety and a distance of ca. 8.0 A from this nitrogen to the aromatic ring are of great importance for high affinity and selectivity for 5-HT4 receptors. These results confirm our recently proposed model for recognition by the 5-HT4 binding site. Amides 12-15 and esters 24 and 25 bound at central 5-HT4 sites with very high affinity (Ki = 0.11-2.9 nM) and excellent selectivity over serotonin 5-HT3, 5-HT2A, and 5-HT1A receptors (Ki > 1000-10,000 nM). Analogues 12 (Ki(5-HT4) = 0.32 nM), 13 (Ki(5-HT4) = 0.11 nM), 14 (Ki(5-HT4) = 0.29 nM) and 15 (Ki(5-HT4) = 0.54 nM) were pharmacologically characterized as selective 5-HT4 antagonists in the isolated guinea pig ileum (pA2 = 7.6, 7.9, 8.2 and 7.9, respectively), with a potency comparable to the 5-HT4 receptor antagonist RS 39604 (pA2 = 8.2). The benzimidazole-4-carboxylic acid derivatives described in this paper represent a novel class of potent and selective 5-HT4 receptor antagonists. In particular, compounds 12-15 could be interesting pharmacological tools for the understanding of the role of 5-HT4 receptors.
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Affiliation(s)
- M L López-Rodríguez
- Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain.
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100
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Matsumoto M, Togashi H, Mori K, Ueno K, Miyamoto A, Yoshioka M. Characterization of endogenous serotonin-mediated regulation of dopamine release in the rat prefrontal cortex. Eur J Pharmacol 1999; 383:39-48. [PMID: 10556679 DOI: 10.1016/s0014-2999(99)00636-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Endogenous serotonin (5-hydroxytryptamine, 5-HT)-mediated regulation of dopamine release in the rat prefrontal cortex was pharmacologically characterized using in vivo microdialysis. To increase synaptic 5-HT availability, a selective 5-HT uptake inhibitor fluoxetine was applied via the dialysis probe. Local perfusion of fluoxetine (30 and 100 microM) increased dopamine levels in a concentration-dependent manner. The fluoxetine (100 microM)-induced increases in dopamine release were abolished by pretreatment with the 5-HT(1B/1D) receptor antagonist GR 127935 (N-[4-methoxy-3-(4-methyl-1-piperazinyl)phenyl]-2'-methyl-4'-(5- methyl-1,2,4-oxadiazol-3-yl)-[1,1-biphenyl]-4-carboxamide] ) (10 and 100 microM). The facilitation of dopamine release was also prevented by selective inactivation of the mRNA encoding 5-HT(6) receptors using antisense oligonucleotides techniques. These findings suggest that not only 5-HT(1B) receptors but also 5-HT(6) receptors are associated with the endogenous 5-HT-mediated facilitation of dopamine release. In other words, 5-HT(6) receptors may play, in part, a significant role in the functional interaction between the dopaminergic and serotonergic neuronal system in the rat prefrontal cortex.
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Affiliation(s)
- M Matsumoto
- Department of Pharmacology, Hokkaido University School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo, Japan.
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