Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Pharmacol Res ; 202: 107111, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38382648

RESUMO

The discovery of brain therapeutics faces a significant challenge due to the low translatability of preclinical results into clinical success. To address this gap, several efforts have been made to obtain more translatable neuronal models for phenotypic screening. These models allow the selection of active compounds without predetermined knowledge of drug targets. In this review, we present an overview of various existing models within the field, examining their strengths and limitations, particularly in the context of neuropathic pain research. We illustrate the usefulness of these models through a comparative review in three crucial areas: i) the development of novel phenotypic screening strategies specifically for neuropathic pain, ii) the validation of the models for both primary and secondary screening assays, and iii) the use of the models in target deconvolution processes.


Assuntos
Neuralgia , Humanos , Neuralgia/tratamento farmacológico , Encéfalo
2.
Biochem Pharmacol ; 177: 113985, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32311347

RESUMO

The 5-HT2A receptor is a homodimeric G protein-coupled receptor implied in multiple diseases, including schizophrenia. Recently, its co-crystallisation with the antipsychotic drugs zotepine and risperidone has revealed the importance of its extracellular domains in its pharmacology. Previous studies have shown that the non-specific disruption of extracellular disulphide bridges in the 5-HT2A receptor decreases ligand binding and receptor activation. There is enough evidence to hypothesize that this decrease may be due to a reduction of the disulphide bridge that links transmembrane domain 3 (TM-3) and extracellular loop 2 (ECL-2) of the 5-HT2A receptor via cysteine 148 (C148) and C227. Thus, to study the influence of the C148-C227 disulphide bridge on 5-HT2A receptor pharmacology, we substituted C148 and C227 in the human 5-HT2A receptor (WT) with alanines, to obtain two single mutants (C148A and C227A) and a double mutant (C148A/C227A), and the resultant DNA constructs were used to generate four stable cell lines. These substitutions reduced the binding of the 5-HT2A receptor to [3H]lysergic acid diethylamide ([3H]LSD) and impeded the 5-HT2A receptor-mediated activation of phospholipase C (PLC). Furthermore, bioluminescence resonance energy transfer (BRET) and western blotting analysis revealed that these mutations did not alter the homodimeric nature of the 5-HT2A receptor. However, fluorescence microscopy showed that these mutations hindered receptor trafficking to the cell membrane. These results illustrate the importance of the disulphide bridge between TM-3 and ECL-2 in maintaining the correct 5-HT2A receptor conformation to allow ligand binding and migration of the homodimeric receptor to the cell membrane.


Assuntos
Cálcio/metabolismo , Membrana Celular/metabolismo , Dissulfetos/química , Receptor 5-HT2A de Serotonina/química , Fosfolipases Tipo C/metabolismo , Sequência de Aminoácidos , Substituição de Aminoácidos , Sítios de Ligação , Linhagem Celular , Membrana Celular/química , Membrana Celular/efeitos dos fármacos , Efeito Fundador , Expressão Gênica , Células HEK293 , Humanos , Ligantes , Dietilamida do Ácido Lisérgico/farmacologia , Mutação , Ligação Proteica , Multimerização Proteica , Transporte Proteico , Receptor 5-HT2A de Serotonina/genética , Receptor 5-HT2A de Serotonina/metabolismo , Proteínas Recombinantes , Serotonina/farmacologia , Fosfolipases Tipo C/genética
3.
Medchemcomm ; 7(6): 1237-1244, 2016 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-27774140

RESUMO

Phenotypic screening is in a renaissance phase and is expected by many academic and industry leaders to accelerate the discovery of new drugs for new biology. Given that phenotypic screening is per definition target agnostic, the emphasis of in silico and in vitro follow-up work is on the exploration of possible molecular mechanisms and efficacy targets underlying the biological processes interrogated by the phenotypic screening experiments. Herein, we present six exemplar computational protocols for the interpretation of cellular phenotypic screens based on the integration of compound, target, pathway, and disease data established by the IMI Open PHACTS project. The protocols annotate phenotypic hit lists and allow follow-up experiments and mechanistic conclusions. The annotations included are from ChEMBL, ChEBI, GO, WikiPathways and DisGeNET. Also provided are protocols which select from the IUPHAR/BPS Guide to PHARMACOLOGY interaction file selective compounds to probe potential targets and a correlation robot which systematically aims to identify an overlap of active compounds in both the phenotypic as well as any kinase assay. The protocols are applied to a phenotypic pre-lamin A/C splicing assay selected from the ChEMBL database to illustrate the process. The computational protocols make use of the Open PHACTS API and data and are built within the Pipeline Pilot and KNIME workflow tools.

4.
Neuroscience ; 290: 165-74, 2015 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-25637489

RESUMO

Reelin is an extracellular matrix protein that plays a critical role in neuronal guidance during brain neurodevelopment and in synaptic plasticity in adults and has been associated with schizophrenia. Reelin mRNA and protein levels are reduced in various structures of post-mortem schizophrenic brains, in a similar way to those found in heterozygous reeler mice (HRM). Reelin is involved in protein expression in dendritic spines that are the major location where synaptic connections are established. Thus, we hypothesized that a genetic deficit in reelin would affect the expression and function of dopamine D2 and serotonin 5-HT2A receptors that are associated with the action of current antipsychotic drugs. In this study, D2 and 5-HT2A receptor expression and function were quantitated by using radioligand binding studies in the frontal cortex and striatum of HRM and wild-type mice (WTM). We observed increased expression (p<0.05) in striatum membranes and decreased expression (p<0.05) in frontal cortex membranes for both dopamine D2 and serotonin 5-HT2A receptors from HRM compared to WTM. Our results show parallel alterations of D2 and 5-HT2A receptors that are compatible with a possible hetero-oligomeric nature of these receptors. These changes are similar to changes described in schizophrenic patients and provide further support for the suitability of using HRM as a model for studying this disease and the effects of antipsychotic drugs.


Assuntos
Moléculas de Adesão Celular Neuronais/metabolismo , Corpo Estriado/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Lobo Frontal/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Receptor 5-HT2A de Serotonina/metabolismo , Receptores de Dopamina D2/metabolismo , Serina Endopeptidases/metabolismo , Animais , Moléculas de Adesão Celular Neuronais/genética , Proteínas da Matriz Extracelular/genética , Feminino , Guanosina Trifosfato/análogos & derivados , Dietilamida do Ácido Lisérgico , Masculino , Camundongos , Camundongos Mutantes Neurológicos , Proteínas do Tecido Nervoso/genética , Ensaio Radioligante , Proteína Reelina , Serina Endopeptidases/genética , Radioisótopos de Enxofre , Trítio
5.
Mol Pharm ; 10(8): 3232-41, 2013 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-23763603

RESUMO

Amphiphilic polymeric micelles greatly improve the solubilization and sustained release of hydrophobic drugs and provide a protective environment for the cargo molecules in aqueous media, which favors lower drug administration doses, reduces adverse side effects, and increases blood circulation times and passive targeting to specific cells. These capabilities depend, among other variables, on the structure and composition of the polymer chains. Composition and, in particular, block length have been shown to play an important role in the modification of cellular responses such as drug internalization processes or transduction pathways when polymeric unimer/micelles are in close contact with cells. Here we present a detailed study about the role copolymer structure and composition play on cell viability and cellular response of several cell lines. To do that, more than 30 structurally related copolymers with diblock and triblock architectures containing different hydrophobic blocks and poly(ethylene oxide) as the common hydrophilic unit have been analyzed regarding cytocompatibility and potential as "active" cell response modifiers by testing their influence on the P-gp pump efflux mechanism responsible of multidrug resistance in cancerous cells. An empirical threshold for cell viability could be established at a copolymer EO/POeffective value above ca. 1.5 for copolymers with triblock structure, whereas no empirical rule could be observed for diblocks. Moreover, some of the tested copolymers (e.g., BO12EO227BO12 and EO57PO46EO57 that notably increased and C16EO455C16 that decreased the P-gp ATPase activity) were observed to act as efficient inhibitors of the P-gp efflux pump promoting an enhanced doxorubicin (DOXO) accumulation inside multidrug resistant (MDR) NCI-ADR-RES cells.


Assuntos
Polímeros/química , Subfamília B de Transportador de Cassetes de Ligação de ATP/química , Animais , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/química , Doxorrubicina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Camundongos , Microscopia Confocal , Polímeros/efeitos adversos , Relação Estrutura-Atividade , Verapamil/química
6.
Int J Pharm ; 445(1-2): 47-57, 2013 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-23380628

RESUMO

Five reverse poly(butylene oxide)-poly(ethylene oxide)-poly(butylene oxide) block copolymers, BOnEOmBOn, with BO ranging from 8 to 21 units and EO from 90 to 411 were synthesized and evaluated as efficient chemotherapeutic drug delivery nanocarriers and inhibitors of the P-glycoprotein (P-gp) efflux pump in a multidrug resistant (MDR) cell line. The copolymers were obtained by reverse polymerization of poly(butylene oxide), which avoids transfer reaction and widening of the EO block distribution, commonly found in commercial poly(ethylene oxide)-poly(propylene oxide) block copolymers (poloxamers). BOnEOmBOn copolymers formed spherical micelles of 10-40 nm diameter at lower concentrations (one order of magnitude) than those of equivalent poloxamers. The influence of copolymer block lengths and BO/EO ratios on the solubilization capacity and protective environment for doxorubicin (DOXO) was investigated. Micelles showed drug loading capacity ranging from ca. 0.04% to 1.5%, more than 150 times the aqueous solubility of DOXO, and protected the cargo from hydrolysis for more than a month due to their greater colloidal stability in solution. Drug release profiles at various pHs, and the cytocompatibility and cytotoxicity of the DOXO-loaded micelles were assessed in vitro. DOXO loaded in the polymeric micelles accumulated more slowly inside the cells than free DOXO due to its sustained release. All copolymers were found to be cytocompatible, with viability extents larger than 95%. In addition, the cytotoxicity of DOXO-loaded micelles was higher than that observed for free drug solutions in a MDR ovarian NCI-ADR-RES cell line which overexpressed P-gp. The inhibition of the P-gp efflux pump by some BOnEOmBOn copolymers, similar to that measured for the common P-gp inhibitor verapamil, favored the retention of DOXO inside the cell increasing its cytotoxic activity. Therefore, poly(butylene oxide)-poly(ethylene oxide) block copolymers offer interesting features as cell response modifiers to complement their role as efficient nanocarriers for cancer chemotherapy.


Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Doxorrubicina/administração & dosagem , Portadores de Fármacos/administração & dosagem , Polietilenoglicóis/administração & dosagem , Células 3T3 , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Camundongos , Micelas
7.
J Control Release ; 167(1): 68-75, 2013 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-23352909

RESUMO

Two poly(styrene oxide)-poly(ethylene oxide) (PSO-PEO) triblock copolymers with different chain lengths were analyzed as potential chemotherapeutic nanocarriers, and their ability to inhibit the P-glycoprotein (P-gp) efflux pump in a multidrug resistant (MDR) cell line were measured in order to establish possible cell-responses induced by the presence of the copolymer molecules. Thus, EO33SO14EO33 and EO38SO10EO38 polymeric micelles were tested regarding doxorubicin (DOXO) entrapment efficiency (solubilization test), physical stability (DLS), cytocompatibility (fibroblasts), release profiles at various pHs (in vitro tests), as well as P-gp inhibition and evasion and cytotoxicity of the DOXO-loaded micelles in an ovarian MDR NCI-ADR/RES cell line and in DOXO-sensitive MCF-7 cells. EO33SO14EO33 and EO38SO10EO38 formed spherical micelles (~13nm) at lower concentration than other copolymers under clinical evaluation (e.g. Pluronic®), exhibited 0.2% to 1.8% loading capacity, enhancing more than 60 times drug apparent solubility, and retained the cargo for long time. The copolymer unimers inhibited P-gp ATPase activity in a similar way as Pluronic P85, favoring DOXO accumulation in the resistant cell line, but not in the sensitive cell line. DOXO loaded in the micelles accumulated more slowly inside the cells, but caused greater cytotoxicity than free drug solutions in the NCI-ADR-RES cell line, which overexpressed P-gp. Hence, PSO-PEO block copolymers offer interesting features as new biological response modifiers to be used in the design of efficient nanocarriers for cancer chemotherapy.


Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Doxorrubicina/administração & dosagem , Portadores de Fármacos/administração & dosagem , Nanopartículas/administração & dosagem , Polietilenoglicóis/administração & dosagem , Poliestirenos/administração & dosagem , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Adenosina Trifosfatases/metabolismo , Antibióticos Antineoplásicos/química , Linhagem Celular Tumoral , Doxorrubicina/química , Portadores de Fármacos/química , Resistencia a Medicamentos Antineoplásicos , Estabilidade de Medicamentos , Humanos , Micelas , Nanopartículas/química , Polietilenoglicóis/química , Poliestirenos/química
8.
J Microencapsul ; 30(2): 181-8, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23088320

RESUMO

This article describes the development of a freeze-dried formulation of chitosan (CS) nanocapsules containing docetaxel (DCX) and the evaluation of its efficacy in the NCI-H460 cancer cell line. More specifically, two prototypes of nanocapsules differing in their coating, CS alone or in combination with poloxamer 188 were developed using the solvent displacement technique. These prototypes (150 nm and +45 mV) exhibited high encapsulation efficiencies of DCX (78%) and very similar release profiles. The nanocapsules made of solely CS could be freeze-dried and reconstituted without altering their particle size distribution. CS nanocapsules were tested for their ability to deliver intracellularly the anticancer drug DCX. The results showed that CS nanocapsules maintained the antiproliferative effect of the drug and that it was not affected by the freeze-drying process. Moreover, it was found that this cytostatic effect of DCX was related to its intracellular delivery in the cancer cells.


Assuntos
Antineoplásicos , Quitosana , Sistemas de Liberação de Medicamentos/métodos , Nanocápsulas/química , Neoplasias/tratamento farmacológico , Taxoides , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Quitosana/química , Quitosana/farmacocinética , Quitosana/farmacologia , Docetaxel , Liofilização , Humanos , Neoplasias/metabolismo , Neoplasias/patologia , Poloxâmero/química , Poloxâmero/farmacocinética , Poloxâmero/farmacologia , Taxoides/química , Taxoides/farmacocinética , Taxoides/farmacologia
9.
Int J Pharm ; 381(2): 122-9, 2009 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-19467809

RESUMO

The purpose of this study was to produce mucoadhesive nanocarriers made from chitosan (CS) and hyaluronic acid (HA), and containing the macromolecular drug heparin, suitable for pulmonary delivery. For the first time, this drug was tested in ex vivo experiments performed in mast cells, in order to investigate the potential of the heparin-loaded nanocarriers in antiasthmatic therapy. CS and mixtures of HA with unfractionated or low-molecular-weight heparin (UFH and LMWH, respectively) were combined to form nanoparticles by the ionotropic gelation technique. The resulting nanoparticles loaded with UFH were between 162 and 217 nm in size, and those prepared with LMWH were 152 nm. The zeta potential of the nanoparticle formulations ranged from +28.1 to +34.6 mV, and in selected nanosystems both types of heparin were associated with a high degree of efficiency, which was approximately 70%. The nanosystems were stable in phosphate buffered saline (PBS), pH 7.4, for at least 24h, and released 10.8% of UFH and 79.7% of LMWH within 12h of incubation. Confocal microscopy experiments showed that fluorescent heparin-loaded CS-HA nanoparticles were effectively internalized by rat mast cells. Ex vivo experiments aimed at evaluating the capacity of heparin to prevent histamine release in rat mast cells indicated that the free or encapsulated drug exhibited the same dose-response behaviour.


Assuntos
Antiasmáticos/administração & dosagem , Degranulação Celular/efeitos dos fármacos , Quitosana/química , Sistemas de Liberação de Medicamentos/métodos , Heparina/administração & dosagem , Heparina/química , Ácido Hialurônico/química , Mastócitos/fisiologia , Nanopartículas/química , Algoritmos , Animais , Asma/tratamento farmacológico , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/síntese química , Portadores de Fármacos/química , Estabilidade de Medicamentos , Endocitose/fisiologia , Feminino , Heparina/farmacologia , Heparina/fisiologia , Heparina de Baixo Peso Molecular/química , Liberação de Histamina/efeitos dos fármacos , Concentração Inibidora 50 , Mastócitos/patologia , Nanopartículas/ultraestrutura , Tamanho da Partícula , Ratos , Ratos Sprague-Dawley , p-Metoxi-N-metilfenetilamina/metabolismo
10.
Naunyn Schmiedebergs Arch Pharmacol ; 368(2): 79-90, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12861437

RESUMO

Most studies of 5-HT(2) receptor regulation have been carried out on the central nervous system (CNS) (which expresses 5-HT(2A) and 5-HT(2C) receptors); very few in vitro studies have addressed the peripheral receptors 5-HT(2A) and 5-HT(2B). The aim of this investigation was to compare the possible short- and long-term processes regulating these peripheral receptors in the rat. The in vitro contractile response elicited by serotonin (5-HT, 10 micro M) in the rat gastric fundus (5-HT(2B) receptor system) was rapid and followed by a partial fade to a steady state, in contrast with the rat thoracic aorta response (5-HT(2A) receptor system), which was more stable, slower and sustained. To characterize drug-receptor interactions, cumulative concentration/response curves (CCRCs) for 5-HT were constructed ex vivo for rat tissues treated with drugs acting at these receptors. Rats were examined 4 or 24 h after a single, i.p. administration of (+/-)1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane [(+/-)DOI, 1 or 2.5 mg/kg], clozapine, cyproheptadine or rauwolscine (10 mg/kg), 48 h after a single i.p. administration of (+/-)DOI (2.5 mg/kg), clozapine or cyproheptadine (10 mg/kg) or 24 h after the last of with 15 daily i.p. administrations of (+/-)DOI (1 or 2.5 mg/kg), clozapine, cyproheptadine or rauwolscine (10 mg/kg). In the aorta, E(max) (the maximum response elicited by 5-HT) was unchanged 4 h after a single dose of any of the drugs tested. However, 24 h after a single dose, E(max) was lower in animals treated with (+/-)DOI (2.5 mg/kg), clozapine or cyproheptadine than in controls, whilst 48 h after a single dose of (+/-)DOI (2.5 mg/kg), clozapine or cyproheptadine there was no difference in E(max) between experimental and control animals. After chronic treatment with (+/-)DOI (2.5 mg/kg), clozapine and cyproheptadine, E(max) was lower than in controls. In the gastric fundus, E(max) 4 h after a single dose of each drug was lower than in controls, and the response recovered by 24 or 48 h. Following chronic treatment, E(max) was significantly lower than in controls for each drug used. These findings suggest first, that regulation of peripheral 5-HT(2) receptors (5-HT(2A) and 5-HT(2B)) is a functionally significant phenomenon in vivo, and occurs after administration of both agonists and antagonists. Second, the kinetics of peripheral 5-HT(2) receptor regulation were similar in both in vivo and ex vivo experiments. The 5-HT(2B) receptors in rat gastric fundus are more sensitive to drug-induced regulation than the 5-HT(2A) rat aortic receptors. Finally, long-term regulation of both receptors stabilizes short-term desensitization for longer.


Assuntos
Músculo Liso/efeitos dos fármacos , Receptor 5-HT2A de Serotonina/efeitos dos fármacos , Receptor 5-HT2B de Serotonina/efeitos dos fármacos , Anfetaminas/farmacologia , Animais , Antipsicóticos/farmacologia , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/metabolismo , Aorta Torácica/fisiologia , Clozapina/farmacologia , Ciproeptadina/farmacologia , Fundo Gástrico/efeitos dos fármacos , Fundo Gástrico/metabolismo , Fundo Gástrico/fisiologia , Técnicas In Vitro , Ligantes , Masculino , Contração Muscular/efeitos dos fármacos , Músculo Liso/metabolismo , Músculo Liso/fisiologia , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/fisiologia , Ratos , Ratos Sprague-Dawley , Receptor 5-HT2A de Serotonina/metabolismo , Receptor 5-HT2B de Serotonina/metabolismo , Serotonina/metabolismo , Antagonistas da Serotonina/farmacologia , Agonistas do Receptor de Serotonina/farmacologia , Ioimbina/farmacologia
11.
Bioorg Med Chem Lett ; 13(2): 175-8, 2003 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-12482418

RESUMO

A series of novel long-chain arylpiperazines bearing a coumarin fragment was synthesized and the compounds were evaluated for their affinity at alpha(1), D(2 )and 5-HT(2A) receptors. Most of the new compounds showed high affinity for the three types of receptors alpha(1A), D(2) and 5-HT(2A) which depends, fundamentally, on the substitution of the N(4) of the piperazine ring. From the series emerged compound 6, which had an haloperidol-like profile at D(2) and 5HT(2A) receptors (pK(i) values of 7.93 and 6.76 respectively). The higher alpha(1A) receptor affinity (pA(2)=9.07) of this compound could contribute to a more atypical antipsychotic profile than the haloperidol.


Assuntos
Piperazinas/síntese química , Piperazinas/farmacologia , Receptores Adrenérgicos alfa 1/efeitos dos fármacos , Receptores de Dopamina D2/efeitos dos fármacos , Receptores de Serotonina/efeitos dos fármacos , Algoritmos , Animais , Aorta Torácica/efeitos dos fármacos , Cumarínicos/química , Antagonistas de Dopamina/farmacologia , Haloperidol/farmacologia , Técnicas In Vitro , Indicadores e Reagentes , Masculino , Músculo Liso Vascular/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Receptor 5-HT2A de Serotonina , Relação Estrutura-Atividade
12.
Mol Pharmacol ; 60(4): 690-9, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11562430

RESUMO

We have expanded previous studies with the 5-hydroxytryptamine (5-HT)(2) receptor agonist (+/-)-1-(2,5-dimethoxy-4-[(125)I]iodophenyl)-2-aminopropane [(+/-)-[(125)I]DOI] in human brain that had shown biphasic competition curves for several 5-HT(2A) receptor antagonists by using new selective antagonists of 5-HT(2A) (MDL100,907) and 5-HT(2C) (SB242084) receptors together with ketanserin and mesulergine. Autoradiographic competition experiments were performed with these antagonists in human brain regions where (+/-)-[(125)I]DOI labels almost exclusively 5-HT(2A) receptors (frontal cortex and striosomes). Furthermore, the effect of uncoupling receptor/G protein complexes on antagonist competition was studied with guanosine-5'-(beta,gamma-imido)triphosphate [Gpp(NH)p]. Competition experiments with (+/-)-[(3)H]1-(4-bromo-2,5-dimethoxyphenil)-2-aminopropane [(+/-)-[(3)H]DOB] were also performed in membranes from Chinese hamster ovary cells (CHOFA4) expressing cloned human 5-HT(2A) receptors. In both systems, ketanserin and MDL100,907 displayed biphasic competition profiles, whereas SB242084 and mesulergine competed monophasically. In absence of antagonist, 100 microM Gpp(NH)p decreased brain (+/-)-[(125)I]DOI specific binding by 40 to 50% and (+/-)-[(3)H]DOB specific binding to CHOFA4 cells by 30%. The remaining agonist-labeled uncoupled sites were still displaced biphasically by ketanserin and MDL100,907, with unaltered affinities. Saturation experiments were performed in CHOFA4 cells. (+/-)-[(3)H]DOB labeled two sites (K(d(h))= 0.8 nM, K(d(l)) = 31.22 nM). Addition of 100 microM Gpp(NH)p resulted in a single low-affinity (K(d) = 24.44 nM) site with unchanged B(max). [(3)H]5-HT showed no specific binding to 5-HT(2A) receptors. These results conform with the extended ternary complex model of receptor action that postulates the existence of partly activated receptor conformation(s) (R*) in equilibrium with the ground (R) and the activated G protein-coupled (R*G) conformations. Thus, both in human brain and CHOFA4 cells, the agonists possibly label all three conformations and ketanserin and MDL100,907 recognize with different affinities at least two of these conformations.


Assuntos
Encéfalo/metabolismo , Receptores de Serotonina/química , Animais , Autorradiografia , Sítios de Ligação , Células CHO , Cricetinae , Fluorbenzenos/farmacologia , Humanos , Fosfatos de Inositol/metabolismo , Piperidinas/farmacologia , Conformação Proteica/efeitos dos fármacos , Receptor 5-HT2A de Serotonina , Receptores de Serotonina/efeitos dos fármacos , Receptores de Serotonina/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/efeitos dos fármacos , Proteínas Recombinantes/metabolismo , Antagonistas da Serotonina/farmacologia , Agonistas do Receptor de Serotonina/farmacologia , Transfecção , Trítio
13.
J Med Chem ; 43(24): 4678-93, 2000 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-11101359

RESUMO

A series of novel conformationally restricted butyrophenones (6-aminomethyl-4,5,6,7-tetrahydrobenzo[b]furan-4-ones bearing 4-(6-fluorobenzisoxazolyl)piperidine, 4-(p-fluorobenzoyl)piperidine, 4-(o-methoxyphenyl)piperazine, 4-(2-pyridyl)piperazine, 4-(2-pyrimidinyl)piperazine, or linear butyro(or valero)phenone fragments) were prepared and evaluated as antipsychotic agents by in vitro assays for affinity for dopamine receptors (D(1), D(2), D(4)) and serotonin receptors (5-HT(2A), 5-HT(2B), 5-HT(2C)), by neurochemical studies, and by in vivo assays for antipsychotic potential and the risk of inducing extrapyramidal side effects. Potency and selectivity depended mainly on the amine fragment connected to the cyclohexanone structure. Compounds 20b, with a benzoylpiperidine moiety, and 20c, with a benzisoxazolyl fragment, were selective for 5-HT(2A) receptors. The in vitro and in vivo pharmacological profiles of N-[(4-oxo-4,5,6, 7-tetrahydrobenzo[b]furan-6-yl)methyl]-4-(p-fluorobenzoyl)piperidine (20b, QF1003B) and N-[(4-oxo-4,5,6, 7-tetrahydrobenzo[b]furan-6-yl)methyl]-4-(6-fluorobenzisoxazol-3-yl)p iperidine (20c, QF1004B) suggest that they may be effective as antipsychotic (neuroleptic) drugs.


Assuntos
Antipsicóticos/síntese química , Butirofenonas/síntese química , Isoxazóis/síntese química , Piperidinas/síntese química , Receptores Dopaminérgicos/metabolismo , Receptores de Serotonina/metabolismo , Animais , Antipsicóticos/química , Antipsicóticos/metabolismo , Antipsicóticos/farmacologia , Comportamento Animal/efeitos dos fármacos , Ligação Competitiva , Butirofenonas/química , Butirofenonas/metabolismo , Butirofenonas/farmacologia , Catalepsia/induzido quimicamente , Bovinos , Corpo Estriado/metabolismo , Lobo Frontal/metabolismo , Humanos , Técnicas In Vitro , Isoxazóis/química , Isoxazóis/metabolismo , Isoxazóis/farmacologia , Masculino , Camundongos , Piperidinas/química , Piperidinas/metabolismo , Piperidinas/farmacologia , Ensaio Radioligante , Ratos , Ratos Sprague-Dawley , Receptor 5-HT2A de Serotonina , Receptor 5-HT2B de Serotonina , Receptor 5-HT2C de Serotonina , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D2/metabolismo , Receptores de Dopamina D4 , Retina/metabolismo
16.
Biol Pharm Bull ; 23(5): 558-65, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10823664

RESUMO

The in vivo and in vitro cardiovascular effects of the novel 5-HT2A/alpha1/H1 antagonist ketanserin analogues QF 0303B, QF 0307B, QF 0311B, QF 0313B were studied in anaesthetized normotensive rats (ANR) and in isolated rubbed rat aorta (IRRA). In ANR, 0.2 mg x kg(-1) i.v. of each compound produced a rapid, remarkable but short-lasting fall in mean arterial blood pressure (MAP) accompanied by bradycardia. All compounds significantly modified the pressor effects induced by 5-hydroxytryptamine (5-HT) and noradrenaline (NA). In IRRA, the compounds inhibited NA- and 5-HT-induced contractions in a competitive fashion. Furthermore, the analogues displayed lower H1-antagonist activity than ketanserin. Compounds tested showed low 5-HT2B affinity and no activity at muscarinic, nicotinic, or 5-HT3 receptors, nor any marked ability to produce smooth muscle relaxation via calcium entry blockade. There is a significant correlation between hypotension reached and inhibition of the 5-HT-induced pressor responses (but not for NA). A certain degree of correlation was observed between hypotensive effect endurance vs. alpha1-adrenoceptor blockade (but not for serotonin). These results indicate that in this series the brief hypotensive activity in ANR is attributed to a 5-HT1A receptor blockade and the duration of the effect is better attributed to an alpha1 adrenoceptor blockade.


Assuntos
Anti-Hipertensivos/farmacologia , Ketanserina/farmacologia , Receptores Adrenérgicos alfa 1/metabolismo , Receptores de Serotonina/metabolismo , Antagonistas Adrenérgicos alfa/farmacologia , Animais , Anti-Hipertensivos/química , Aorta , Cobaias , Íleo/efeitos dos fármacos , Íleo/metabolismo , Ketanserina/análogos & derivados , Ketanserina/química , Masculino , Músculos/efeitos dos fármacos , Músculos/metabolismo , Cloreto de Potássio/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor 5-HT2A de Serotonina , Receptor 5-HT2B de Serotonina , Receptores Adrenérgicos alfa 1/efeitos dos fármacos , Receptores Histamínicos H1/efeitos dos fármacos , Receptores Histamínicos H1/metabolismo , Receptores de Serotonina/efeitos dos fármacos , Receptores 5-HT3 de Serotonina , Antagonistas da Serotonina/farmacologia , Vasoconstrição/efeitos dos fármacos
17.
Eur J Med Chem ; 35(1): 83-95, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10733606

RESUMO

We describe practical and efficient routes for synthesis of 2-aminomethyl-1,2,3,9-tetrahydro-4H-carbazol-4-ones using the Fischer indole synthesis or palladium-catalysed cyclization methodologies, as well as their affinities for D(2), 5-HT(2A) and 5-HT(2C) receptors, and their activity at the 5-HT(2B) receptor. The most active compounds, 4b (QF 2003B) and 4c (QF 2004B), with a pK(i) (5-HT(2A)/D(2)) ratio of 1.28 show a potential antipsychotic profile according to Meltzer's classification.


Assuntos
Antipsicóticos/síntese química , Antipsicóticos/metabolismo , Butirofenonas/química , Carbazóis/química , Receptores de Dopamina D2/metabolismo , Receptores de Serotonina/metabolismo , Animais , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/fisiologia , Carbazóis/síntese química , Carbazóis/metabolismo , Carbazóis/farmacologia , Bovinos , Membrana Celular/metabolismo , Plexo Corióideo/metabolismo , Lobo Frontal/metabolismo , Isoxazóis/síntese química , Isoxazóis/metabolismo , Isoxazóis/farmacologia , Masculino , Piperazinas/síntese química , Piperazinas/metabolismo , Piperazinas/farmacologia , Ratos , Ratos Sprague-Dawley , Antagonistas da Serotonina/farmacologia
18.
Gen Pharmacol ; 35(2): 95-105, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11707316

RESUMO

In this work, we report for first time that: (1) low doses of ketanserin (0.2 mg/kg) produce a transient hypotensive response in anaesthetized rats, which is basically due to the blockade of 5-hydroxytryptamine (2A) (5-HT)2A receptors, whereas high doses (1 mg/kg) of ketanserin cause a sustained hypotension also mediated by the blockage of alpha1-adrenergic receptors; (2) the in vitro vasorelaxant action of high concentrations of ketanserin (>10 microM) involves Ca2+ antagonism, which may also be responsible, at least in part, for the inhibition of high-K+-induced 45Ca2+ uptake, the inhibition of Ca2+-induced contractions in initially Ca2+-free high-K+ medium, and the negative chronotropic effects on isolated atria. This Ca2+ antagonistic activity does not seem to contribute to the in vivo cardiovascular effects of ketanserin at therapeutic doses.


Assuntos
Hemodinâmica/efeitos dos fármacos , Ketanserina/farmacologia , Antagonistas da Serotonina/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Cálcio/metabolismo , Relação Dose-Resposta a Droga , Frequência Cardíaca/efeitos dos fármacos , Técnicas In Vitro , Masculino , Norepinefrina/farmacologia , Ratos , Ratos Sprague-Dawley , Serotonina/farmacologia
19.
J Med Chem ; 42(15): 2774-97, 1999 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-10425088

RESUMO

A series of novel conformationally restricted butyrophenones (2-(aminoethyl)- and 3-(aminomethyl)thieno- or benzocycloalkanones bearing (6-fluorobenzisoxazolyl)piperidine, (p-fluorobenzoyl)piperidine, (o-methoxyphenyl)piperazine, or linear butyrophenone fragments) were prepared and evaluated as atypical antipsychotic agents by in vitro assays of affinity for dopamine receptors (D(1), D(2)) and serotonin receptors (5-HT(2A), 5-HT(2C)) and by in vivo assays of antipsychotic potential and the risk of inducing extrapyramidal side effects. Potency and selectivity depended mainly on the amine fragment connected to the cycloalkanone structure. As a group, compounds with a benzisoxazolyl fragment had the highest 5-HT(2A) activities, followed by the benzoylpiperidine derivatives; in general, alpha-substituted cycloalkanone derivatives were more active than the corresponding beta-substituted congeners. CoMFA (comparative molecular field analysis) and docking studies showed electrostatic, steric, and lipophilic determinants of 5-HT(2A) and D(2) affinities and 5-HT(2A)/D(2) selectivity. The in vitro and in vivo pharmacological profiles of N-[(4-oxo-4H-5, 6-dihydrocyclopenta[b]thiophene-5-yl)ethyl]-4-(6-fluorobenzisox azol-3 -yl)piperidine (23b, QF 0510B), N-[(4-oxo-4,5,6, 7-tetrahydrobenzo[b]thiophene-5-yl)ethyl]-4-(6-fluorobenzisoxazol- 3-y l)piperidine (24b, QF 0610B), and N-[(7-oxo-4,5,6, 7-tetrahydrobenzo[b]thiophene-6-yl)ethyl]-4-(6-fluorobenzisoxazol- 3-y l)piperidine (29b, QF 0902B) suggest that they may be effective antipsychotic drugs with low propensity to induce extrapyramidal side effects.


Assuntos
Antipsicóticos/síntese química , Dopaminérgicos/síntese química , Isoxazóis/síntese química , Receptores de Dopamina D2/metabolismo , Receptores de Serotonina/metabolismo , Serotoninérgicos/síntese química , Tiofenos/síntese química , Animais , Antipsicóticos/química , Antipsicóticos/metabolismo , Antipsicóticos/farmacologia , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/fisiologia , Encéfalo/metabolismo , Catalepsia/induzido quimicamente , Bovinos , Dopaminérgicos/química , Dopaminérgicos/metabolismo , Dopaminérgicos/farmacologia , Técnicas In Vitro , Isoxazóis/química , Isoxazóis/metabolismo , Isoxazóis/farmacologia , Masculino , Camundongos , Modelos Moleculares , Atividade Motora/efeitos dos fármacos , Contração Muscular/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/fisiologia , Ensaio Radioligante , Ratos , Ratos Sprague-Dawley , Receptor 5-HT2A de Serotonina , Receptor 5-HT2C de Serotonina , Serotoninérgicos/química , Serotoninérgicos/metabolismo , Serotoninérgicos/farmacologia , Relação Estrutura-Atividade , Tiofenos/química , Tiofenos/metabolismo , Tiofenos/farmacologia
20.
Stud Health Technol Inform ; 68: 764-7, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10724997

RESUMO

One of the applications developed within the EU-funded projects TESEMED and TESEMED-II is a program for the information and continuous training of community pharmacists, with the aim to empower them as advisors of the citizens about self-medication topics. Several programs are being developed on the basis of ad-hoc developed protocols about minor ailments (currently, cold and flu, haemorrhoids, constipation and cough). Each program includes three modules: a hypertextual version of the protocol, an interactive scheme of it, and an educational tool called Encounter Simulator, that trains the pharmacist about the protocol by means of simulated pharmacist-customer interactions. The testing of these applications with 84 community pharmacists offers positive results in terms of expectations, program characteristics and perceived usefulness.


Assuntos
Serviços de Informação sobre Medicamentos , Aplicações da Informática Médica , Farmacêuticos , Automedicação , Resfriado Comum/tratamento farmacológico , Simulação por Computador , União Europeia , Humanos , Influenza Humana/tratamento farmacológico , Software
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...