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1.
Mol Psychiatry ; 19(6): 659-67, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23774715

RESUMO

Autism spectrum disorders (ASDs) represent a formidable challenge for psychiatry and neuroscience because of their high prevalence, lifelong nature, complexity and substantial heterogeneity. Facing these obstacles requires large-scale multidisciplinary efforts. Although the field of genetics has pioneered data sharing for these reasons, neuroimaging had not kept pace. In response, we introduce the Autism Brain Imaging Data Exchange (ABIDE)-a grassroots consortium aggregating and openly sharing 1112 existing resting-state functional magnetic resonance imaging (R-fMRI) data sets with corresponding structural MRI and phenotypic information from 539 individuals with ASDs and 573 age-matched typical controls (TCs; 7-64 years) (http://fcon_1000.projects.nitrc.org/indi/abide/). Here, we present this resource and demonstrate its suitability for advancing knowledge of ASD neurobiology based on analyses of 360 male subjects with ASDs and 403 male age-matched TCs. We focused on whole-brain intrinsic functional connectivity and also survey a range of voxel-wise measures of intrinsic functional brain architecture. Whole-brain analyses reconciled seemingly disparate themes of both hypo- and hyperconnectivity in the ASD literature; both were detected, although hypoconnectivity dominated, particularly for corticocortical and interhemispheric functional connectivity. Exploratory analyses using an array of regional metrics of intrinsic brain function converged on common loci of dysfunction in ASDs (mid- and posterior insula and posterior cingulate cortex), and highlighted less commonly explored regions such as the thalamus. The survey of the ABIDE R-fMRI data sets provides unprecedented demonstrations of both replication and novel discovery. By pooling multiple international data sets, ABIDE is expected to accelerate the pace of discovery setting the stage for the next generation of ASD studies.


Assuntos
Mapeamento Encefálico , Encéfalo/patologia , Encéfalo/fisiopatologia , Transtornos Globais do Desenvolvimento Infantil/patologia , Transtornos Globais do Desenvolvimento Infantil/fisiopatologia , Neuroimagem , Adolescente , Adulto , Criança , Conectoma , Humanos , Disseminação de Informação , Internet , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Vias Neurais/patologia , Vias Neurais/fisiopatologia , Fenótipo , Processamento de Sinais Assistido por Computador , Adulto Jovem
2.
Neurosci Biobehav Rev ; 135: 104581, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35181397

RESUMO

Dysregulation in glutamatergic receptors and transporters has been found to mediate drugs of abuse, including morphine. Among glutamate receptors, ionotropic glutamate receptors (iGluRs) are altered with exposure to drugs of abuse. Acid-sensing ion channels (ASICs) are ligand (H+)-gated channels, which are expressed at the excitatory synaptic clefts and play a role in drug dependence. Overexpression of a specific ASIC subtype, ASIC1a, attenuated reinstatement of cocaine. ASICs are revealed to be involved in cocaine and morphine seeking behaviors, and these effects are mediated through modulation of glutamatergic receptors. In this review, we discussed the interactive role of ASICs and glutamate receptors, mainly iGluRs, in opioid dependence. ASICs are also expressed in astrocytes and are suggested to be involved on regulating glutamate uptake. However, little is known about the coupling between ASICs and the astroglial glutamate transporters. In addition, this review discussed the role of nitric oxide in the modulation of ASIC function and potentially opioid dependence. We also discussed the role of ASICs in the modulation of the function of both glutamatergic receptors in post-synaptic neurons and glutamatergic transporters in astrocytes in animals exposed to drugs of abuse.


Assuntos
Cocaína , Transtornos Relacionados ao Uso de Opioides , Canais Iônicos Sensíveis a Ácido/farmacologia , Animais , Astrócitos , Cocaína/farmacologia , Humanos , Neurônios/fisiologia
3.
Pharmacology ; 88(1-2): 50-4, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21757975

RESUMO

Cough continues to be one of the top reasons why patients seek medical attention from health care providers. The prescription antitussive market is dominated by opioids, such as codeine that produces inconsistent efficacy and is often accompanied by significant side effect liabilities. Consequently, cough represents an unmet medical need and an underserved market. Yet, against the backdrop of increasing cough research, the development of novel treatments has been exceptionally challenging with dextromethorphan being the last US drug approved for cough almost a half century ago. We support the position that an unambiguous and actionable 'road map' that clearly delineates the pathway forward for new cough suppressants from basic research to and beyond clinical proof-of-concept studies will be an important aspect for future success of this pharmacological class of drug. Pivotal to the establishment of such a road map will be the review of lessons learned from antitussive agents that have been recently progressed to proof-of-concept trials. In the present commentary, we briefly discuss observations and challenges pertaining to SCH 486757, a selective orally active NOP agonist that has recently advanced to human antitussive testing.


Assuntos
Antitussígenos/farmacologia , Compostos Azabicíclicos/farmacologia , Tosse/tratamento farmacológico , Pirimidinas/farmacologia , Animais , Antitussígenos/administração & dosagem , Antitussígenos/uso terapêutico , Compostos Azabicíclicos/administração & dosagem , Compostos Azabicíclicos/uso terapêutico , Ensaios Clínicos como Assunto , Codeína/administração & dosagem , Codeína/farmacologia , Dextrometorfano/administração & dosagem , Dextrometorfano/farmacologia , Modelos Animais de Doenças , Cães , Avaliação Pré-Clínica de Medicamentos , Cobaias , Humanos , Peptídeos Opioides/agonistas , Peptídeos Opioides/metabolismo , Pirimidinas/administração & dosagem , Pirimidinas/uso terapêutico , Ratos , Receptores Opioides/agonistas , Nociceptina
4.
Pilot Feasibility Stud ; 7(1): 33, 2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33504369

RESUMO

BACKGROUND: There is an urgent need to improve quality of care to reduce avoidable mortality and morbidity from surgical diseases in low- and middle-income countries. Currently, there is a lack of knowledge about how evidence-based health system strengthening interventions can be implemented effectively to improve quality of care in these settings. To address this gap, we have developed a multifaceted quality improvement intervention to improve nursing documentation in a low-income country hospital setting. The aim of this pilot project is to test the intervention within the surgical department of a national referral hospital in Freetown, Sierra Leone. METHODS: This project was co-developed and co-designed by in-country stakeholders and UK-based researchers, after a multiple-methodology assessment of needs (qualitative, quantitative), guided by a participatory 'Theory of Change' process. It has a mixed-method, quasi-experimental evaluation design underpinned by implementation and improvement science theoretical approaches. It consists of three distinct phases-(1) pre-implementation(project set up and review of hospital relevant policies and forms), (2) intervention implementation (awareness drive, training package, audit and feedback), and (3) evaluation of (a) the feasibility of delivering the intervention and capturing implementation and process outcomes, (b) the impact of implementation strategies on the adoption, integration, and uptake of the intervention using implementation outcomes, (c) the intervention's effectiveness For improving nursing in this pilot setting. DISCUSSION: We seek to test whether it is possible to deliver and assess a set of theory-driven interventions to improve the quality of nursing documentation using quality improvement and implementation science methods and frameworks in a single facility in Sierra Leone. The results of this study will inform the design of a large-scale effectiveness-implementation study for improving nursing documentation practices for patients throughout hospitals in Sierra Leone. TRIAL REGISTRATION: Protocol version number 6, date: 24.12.2020, recruitment is planned to begin: January 2021, recruitment will be completed: December 2021.

5.
Bioorg Med Chem Lett ; 19(4): 1164-7, 2009 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-19147350

RESUMO

A series of N-8 substituted analogs based upon the spiropiperidine core of the original lead compound 1 was synthesized. This lead has been elaborated to compounds to give compounds 2 and 3 (R=H) that exhibited high NOP binding affinity as well as selectivity against other known opioid receptors. These two series have been further functionalized at the amido nitrogen. The synthesis and structure-activity relationship (SAR) of these and related compounds are discussed.


Assuntos
Piperidinas/síntese química , Piperidinas/farmacologia , Receptores Opioides/efeitos dos fármacos , Compostos de Espiro/síntese química , Compostos de Espiro/farmacologia , Animais , Sítios de Ligação , Capsaicina/farmacologia , Técnicas de Química Combinatória , Tosse/induzido quimicamente , Modelos Animais de Doenças , Desenho de Fármacos , Cobaias , Estrutura Molecular , Piperidinas/química , Receptores Opioides/metabolismo , Compostos de Espiro/química , Relação Estrutura-Atividade , Receptor de Nociceptina
6.
Pharmacology ; 84(3): 153-61, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19696521

RESUMO

BACKGROUND: Previous studies have demonstrated that nociceptin/orphanin FQ (N/OFQ), the endogenous peptide ligand for the G-protein-coupled NOP receptor, inhibits cough in experimental models. SCH 225288 is a nonpeptide, orally active NOP agonist that may provide the foundation for the development of novel treatments for cough. METHODS: First we characterized the selectivity of SCH 225288 in human receptor binding assays. Afterwards, the antitussive activity of SCH 225288 was studied in three mechanistically distinct cough models. Specifically, we observed the cough-suppressant effect of SCH 225288 in a guinea pig capsaicin irritant-evoked cough model, a feline mechanically induced cough model and finally in a canine Bordetella bronchiseptica disease model. RESULTS: SCH 225288 selectively binds human NOP receptor (K(i) = 0.38 +/- 0.02 nmol/l) over classical opioid receptors (COR). In a guinea pig capsaicin cough model, SCH 225288 (0.1-1 mg/kg) suppressed cough at 2, 4, and 6 h after oral administration. The antitussive effect of SCH 225288 (3.0 mg/kg, p.o.) was blocked by the NOP antagonist J113397 (12 mg/kg, i.p.) but not by the classical opioid receptor (COR) antagonist, naltrexone (3.0 mg/kg, i.p.). In the anesthetized cat, we evaluated the effects of SCH 225288 given either intravenously or via the intravertebral artery against the increases in cough number and respiratory expiratory and inspiratory muscle (rectus abdominis and parasternal) electromyographic (EMG) activities due to perturbations of the intrathoracic trachea. SCH 225288 (0.03-3.0 mg/kg, i.v.) inhibited both cough number and abdominal EMG amplitudes. Similarly, SCH 225288 (0.001-0.3 mg/kg) administered intra-arterially also diminished cough number and abdominal EMG amplitudes. No significant effect of the drug was noted on parasternal EMG activity. Finally, we studied the antitussive actions of SCH 225288 (1.0 mg/kg) in a canine B. bronchiseptica disease model. In this model, dogs were challenged intranasally with B. bronchiseptica. Comparisons were made between a vehicle group, an SCH 225288 (1.0 mg/kg, p.o., q.d.) and a butorphanol (0.6 mg/kg, p.o., b.i.d.) group on the mean change in cough scores from baseline values and days 6-9 after B. bronchiseptica challenge. SCH 225288 (1.0 mg/kg, p.o., q.d.) displayed a positive antitussive tendency (p = 0.06) to inhibit B. bronchiseptica cough whereas butorphanol (0.6 mg/kg, p.o., b.i.d.) was devoid of antitussive activity. CONCLUSIONS: Taken together, the present data show that SCH 225288 is a potent and effective antitussive agent in animal models of cough. Furthermore, these findings indicate that NOP agonists represent a promising new therapeutic approach for the treatment of cough without the side effect liabilities associated with opioid antitussives.


Assuntos
Antitussígenos/farmacologia , Tosse/tratamento farmacológico , Receptores Opioides/agonistas , Tropanos/farmacologia , Animais , Antitussígenos/administração & dosagem , Antitussígenos/efeitos adversos , Infecções por Bordetella/tratamento farmacológico , Infecções por Bordetella/veterinária , Bordetella bronchiseptica/isolamento & purificação , Células CHO , Capsaicina , Gatos , Cricetinae , Cricetulus , Modelos Animais de Doenças , Cães , Relação Dose-Resposta a Droga , Feminino , Cobaias , Humanos , Masculino , Especificidade da Espécie , Fatores de Tempo , Tropanos/administração & dosagem , Tropanos/efeitos adversos , Receptor de Nociceptina
7.
J Spine Surg ; 4(2): 311-318, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30069523

RESUMO

BACKGROUND: This is a cross-sectional study. Our objective is to survey spine surgeons' views of responsibility to reduce healthcare costs, enthusiasm for cost reduction strategies, and agreement regarding roles in cost containment. The rising cost of healthcare has spurred debate about reducing expenditures. Previous studies have found that attitudes of anesthesiologists are predominantly in alignment with those of American physicians, but less is known about the views of spine surgeons. METHODS: After obtaining institutional approval, an electronic survey was disseminated to active members of AO Spine North America (AOSNA) via email. Respondents were asked eight questions about their age, gender, years in practice, practice facility, political views and opinions regarding management of healthcare costs. RESULTS: From 91 respondents, most were under the age of 60 years (87%), male (96%), and in practice for less than 30 years (91%), practiced at university hospitals (47%) and held politically conservative views (47%). Most responsibility was allocated to hospital and health systems, health insurance companies, pharmaceutical companies, and device manufacturers. Respondents were most enthusiastic about rooting out fraud and abuse and aware of their role in managing the cost of healthcare. Spine surgeons who were in practice for longer were more enthusiastic about reducing cost by reducing overall physician reimbursement via bundled payments, Medicare payment reduction, ending fee-for-service, penalizing surgeons for patient readmissions, and lowering compensation to individual spine surgeons. CONCLUSIONS: Spine surgeons allocated responsibility to reduce healthcare costs to healthcare systems, were most enthusiastic about eliminating wasteful spending, and were in agreement regarding their responsibility to control the costs of healthcare. Compared to US physicians of various specialties and anesthesiologists, spine surgeons assigned less responsibility to trials lawyers and expressed markedly less enthusiasm for limiting access to expensive treatments.

8.
J Spine Surg ; 4(2): 287-294, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30069520

RESUMO

BACKGROUND: Supplemental intrathecal morphine (ITM) represents an option to manage postoperative pain after spine surgery due to ease of administration and ability to confer effective short-term analgesia at low dosages. However, whether ITM increases risk of surgical site infections (SSI), cerebrospinal fluid (CSF) leak, and incidental dural tears (IDT) has not been investigated. Therefore, this study was performed to determine the rates of SSI, CSF leak, and IDT in patients that received ITM. METHODS: Patients that underwent posterior instrumented fusion from January 2010 to 2016 that received ITM were compared to controls with respect to demographic, medical, surgical, and outcome data. Fisher's exact test was used to compare rates of SSI, CSF leak, and IDT between groups. Poisson regression was used to analyze complication rates after adjusting for the influence of covariates and potential confounders. RESULTS: A total of 512 records were analyzed. ITM was administered to 78 patients prior to wound closure. The remaining 434 patients compromised the control group. IDT was significantly more common among patients receiving ITM (P=0.009). Differences in rates of CSF leak and SSI were not statistically significant (P=0.373 and P=0.564, respectively). After compensating for additional variables, Poisson regression revealed a significant increase in rates of IDT (P=0.007) according to ITM injection and advanced age (P=0.014). There was no significant difference in rates of CSF leak or SSI after accounting for the additional variables (P>0.05). CONCLUSIONS: ITM for pain control in posterior instrumented spinal fusion surgery was linked to increased likelihood of IDT but not CSF leaks or SSI. Age was also noted to be a significant predictor of IDT. Spine surgeons should weigh potential risks against benefits when deciding whether to administer ITM for postoperative pain management following spine surgery.

9.
Eur J Pharmacol ; 630(1-3): 112-20, 2010 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-20006596

RESUMO

We describe the pharmacological and pharmacokinetic profiles of SCH 486757, a nociceptin/orphanin FQ peptide (NOP) receptor agonist that has recently entered human clinical trials for cough. SCH 486757 selectively binds human NOP receptor (K(i)=4.6+/-0.61nM) over classical opioid receptors. In a guinea pig capsaicin cough model, SCH 486757 (0.01-1mg/kg) suppressed cough at 2, 4, and 6h post oral administration with a maximum efficacy occurring at 4h equivalent to codeine, hydrocodone, dextromethorphan and baclofen. The antitussive effects of SCH 486757 (3.0mg/kg, p.o.) was blocked by the NOP receptor antagonist J113397 (12mg/kg, i.p.) but not by naltrexone (10mg/kg, p.o.). SCH 486757 does not produce tolerance to its antitussive activity after a 5-day BID dosing regimen. After acute and chronic dosing paradigms, SCH 486757 (1mg/kg) inhibited capsaicin-evoked coughing by 46+/-9% and 40+/-11%, respectively. In a feline mechanically-evoked cough model, SCH 486757 produces a maximum inhibition of cough and expiratory abdominal electromyogram amplitude of 59 and 61%, respectively. SCH 486757 did not significantly affect inspiratory electromyogram amplitude. We examined the abuse potential of SCH 486757 (10mg/kg, p.o.) in a rat conditioned place preference procedure which is sensitive to classical drugs of abuse, such as amphetamine and morphine. SCH 486757 was without effect in this model. Finally, SCH 486757 displays a good oral pharmacokinetic profile in the guinea pig, rat and dog. We conclude that SCH 486757 has a favorable antitussive profile in preclinical animal models.


Assuntos
Antitussígenos/uso terapêutico , Tosse/tratamento farmacológico , Receptores Opioides/agonistas , Animais , Compostos Azabicíclicos/farmacologia , Gatos , Cães , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Cobaias , Masculino , Pirimidinas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptores Opioides/metabolismo , Receptor de Nociceptina
11.
Bioorg Med Chem Lett ; 17(6): 1659-62, 2007 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-17234414

RESUMO

A novel series of 3-substituted-8-aryl-[1,2,4]-triazolo[5,1-i]purin-5-amine analogs related to Sch 58261 was synthesized in order to identify potent adenosine A(2A) receptor antagonists with improved selectivity over the A(1) receptor, physiochemical properties, and pharmacokinetic profiles as compared to those of Sch 58261. As a result of structural modifications, numerous analogs with excellent in vitro binding affinities and selectivities were identified. Moreover, compound 27 displayed both superior in vitro and highly promising in vivo profiles.


Assuntos
Antagonistas do Receptor A2 de Adenosina , Fármacos Neuroprotetores/farmacologia , Purinas/síntese química , Purinas/farmacologia , Pirimidinas/farmacologia , Triazóis/síntese química , Triazóis/farmacologia , Antagonistas do Receptor A1 de Adenosina , Fenômenos Químicos , Físico-Química , Indicadores e Reagentes , Espectroscopia de Ressonância Magnética , Relação Estrutura-Atividade
12.
Bioorg Med Chem Lett ; 15(8): 2119-22, 2005 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15808481

RESUMO

Structure-activity relationships have been investigated through substitutions at the 9-position of the 2-amino-6-(2-furanyl) purine (5) to identify novel and selective A(2A) adenosine receptor antagonists. Several potent and selective antagonists were identified. In particular, compounds 20, 25, and 26 show very high affinity with excellent selectivity.


Assuntos
Antagonistas do Receptor A2 de Adenosina , Pirimidinas/química , Pirimidinas/farmacologia , Triazóis/química , Triazóis/farmacologia , Linhagem Celular , Humanos , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/fisiologia , Pirimidinas/metabolismo , Receptor A2A de Adenosina/metabolismo , Receptor A2A de Adenosina/fisiologia , Triazóis/metabolismo
13.
Bioorg Med Chem Lett ; 15(5): 1333-6, 2005 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-15713381

RESUMO

In high throughput screening of our file compounds, a novel structure 1 was identified as a potent A(2A) receptor antagonist with no selectivity over the A1 adenosine receptor. The structure-activity relationship investigation using 1 as a template lead to identification of a novel class of compounds as potent and selective antagonists of A(2A) adenosine receptor. Compound 26 was identified to be the most potent A(2A) receptor antagonist (Ki = 0.8 nM) with 100-fold selectivity over the A1 adenosine receptor.


Assuntos
Antagonistas do Receptor A2 de Adenosina , Antiparkinsonianos/síntese química , Compostos Heterocíclicos com 3 Anéis/síntese química , Antagonistas do Receptor A1 de Adenosina , Antiparkinsonianos/classificação , Antiparkinsonianos/farmacologia , Avaliação Pré-Clínica de Medicamentos , Compostos Heterocíclicos com 3 Anéis/farmacologia , Estrutura Molecular , Relação Estrutura-Atividade
14.
Bioorg Med Chem Lett ; 15(16): 3675-8, 2005 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-15982882

RESUMO

The structure-activity relationship (SAR) exploration using 2-(2-furanyl)-7-phenyl[1,2,4]triazolo-[1,5-c]pyrimidin-5-amine (1) as a template led to the identification of a novel class of potent and selective adenosine A2A receptor (AR) antagonists. However, these compounds were found to be associated with significant hERG activity. This report discusses the strategy and outcome of an expanded SAR focused on addressing the hERG liability. As a result, compounds 21 and 24 possess excellent in vitro profiles, highly promising in vivo profiles, and acceptable levels of hERG channel inhibition.


Assuntos
Antagonistas do Receptor A2 de Adenosina , Pirimidinas/farmacologia , Triazóis/farmacologia , Administração Oral , Animais , Catalepsia/tratamento farmacológico , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Humanos , Estrutura Molecular , Atividade Motora/efeitos dos fármacos , Pirimidinas/química , Pirimidinas/classificação , Pirimidinas/uso terapêutico , Ratos , Relação Estrutura-Atividade , Triazóis/química , Triazóis/uso terapêutico
15.
Bioorg Med Chem Lett ; 15(16): 3670-4, 2005 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-15978806

RESUMO

The structure-activity relationship of this novel class of compounds based on 2-(2-furanyl)-7-phenyl[1,2,4]-triazolo[1,5-c]pyrimidin-5-amine, 1, and its analogs was evaluated for their in vitro and in vivo adenosine A(2A) receptor antagonism. Several compounds displayed oral activity at 3 mg/kg in a rat catalepsy model. Specifically, compound 8g displayed an excellent in vitro profile, as well as a highly promising in vivo profile.


Assuntos
Antagonistas do Receptor A2 de Adenosina , Pirimidinas/farmacologia , Triazóis/farmacologia , Administração Oral , Animais , Catalepsia/tratamento farmacológico , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Masculino , Estrutura Molecular , Pirimidinas/química , Pirimidinas/classificação , Pirimidinas/uso terapêutico , Ratos , Relação Estrutura-Atividade , Triazóis/química , Triazóis/uso terapêutico
16.
Pulm Pharmacol Ther ; 15(3): 213-6, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12099766

RESUMO

Cough is an important defensive pulmonary reflex that removes irritants, fluids or foreign materials from the airways. However, often cough is non-productive and requires suppression. Opioid mu receptor agonists, such as codeine are commonly used as antitussive agents and are among the most widely administered drugs in the world. Codeine suppresses the responsiveness of one or more components of the central reflex pathway for cough and is an efficacious antitussive drug for cough due to diverse aetiologies. However, opioids produce side effects that include sedation, addiction potential and constipation. Therefore, novel cough suppressant therapies should maintain or improve upon the antitussive efficacy profile of opioids. Moreover, these novel therapies should have a safety profile significantly better than current antitussive therapies. Presently, we discuss preclinical findings showing that activation of the 'opioid-like' receptor (NOP(1)) inhibits cough in the guinea pig and cat.


Assuntos
Antitussígenos/uso terapêutico , Tosse/tratamento farmacológico , Peptídeos Opioides/uso terapêutico , Receptores Opioides/agonistas , Vasodilatadores/uso terapêutico , Animais , Gatos , Cobaias , Nociceptina
17.
Pharmacology ; 71(3): 143-9, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15161996

RESUMO

We have previously shown that N/OFQ, the endogenous peptide ligand for the 'opioid-like' NOP receptor, inhibits cough in guinea pigs and cats. In the present study we sought to continue our characterization of the cough-suppressant effects of NOP stimulation by profiling the pulmonary and antitussive effects of a novel non-peptide NOP agonist, Ro-64-6198, in guinea pigs. In receptor-binding assays, we confirmed that Ro-64-6198 selectively binds to NOP receptors over other opioid receptors. The Ki values for Ro-64-6198 at NOP, MOP, KOP and DOP receptors was 0.3, 36, 214 and 3,787 nmol/l, respectively. In GTPgammaS-binding assays, Ro-64-6198 displayed >900-fold functional selectivity at NOP relative to MOP receptors. We evaluated the effects of Ro-64-6198 (3 and 10 micromol/l) in isolated guinea pig nodose ganglia cells on the increases in intracellular Ca2+ concentration evoked by capsaicin stimulation (1 x 10(-8)-1 x 10(-6) mol/l). Similar to previously reported data with N/OFQ, Ro-64-6198 (3 and 10 micromol/l) significantly attenuated Ca2+ responses in nodose ganglia cells produced by exposure to capsaicin. The effect of Ro-64-6198 (3 micromol/l) on capsaicin-induced intracellular Ca2+ responses was blocked by the NOP antagonist, J113397 (3 micromol/l). In guinea pig in vivo studies, aerosolized capsaicin (10-300 micromol/l) produced a dose-dependent increase in cough number. Ro-64-6198 given i.p. significantly inhibited cough due to capsaicin (300 micromol/l) exposure. In a duration study we found that the maximum antitussive effect (42 +/- 8% inhibition) of Ro-64-6198 (3 mg/kg) was observed at 1 h after i.p. administration. Also at 1 h after administration, Ro-64-6198 (0.003-3.0 mg/kg, i.p.) produced a dose-dependent inhibition of cough. The antitussive effect of Ro-64-6198 (3 mg/kg, i.p.) was blocked by J113397 (12 mg/kg, i.p.) but not by the classical opioid antagonist naltrexone (10 mg/kg, i.p.). Although the antitussive action of Ro-64-6198 may be mediated by a central and/or a peripheral site of action, we hypothesize that selective oral NOP agonists that do not penetrate the blood-brain barrier may provide a novel approach for the treatment of cough. Moreover, because these drugs do not interact at MOP receptors, they may be devoid of codeine-like side effects such as respiratory depression, sedation, constipation or proclivities for addictive liabilities.


Assuntos
Antitussígenos/farmacologia , Imidazóis/farmacologia , Receptores Opioides/agonistas , Compostos de Espiro/farmacologia , Aerossóis , Animais , Antitussígenos/administração & dosagem , Células CHO , Cálcio/metabolismo , Capsaicina/administração & dosagem , Capsaicina/farmacologia , Tosse/prevenção & controle , Cricetinae , Cricetulus , Relação Dose-Resposta a Droga , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Cobaias , Imidazóis/administração & dosagem , Técnicas In Vitro , Injeções Intraperitoneais , Masculino , Gânglio Nodoso/citologia , Gânglio Nodoso/metabolismo , Receptores Opioides/metabolismo , Compostos de Espiro/administração & dosagem , Receptor de Nociceptina
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