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1.
J Pharm Bioallied Sci ; 16(Suppl 1): S990-S992, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38595387

RESUMO

The case report describes a multidisciplinary approach using orthodontic forced eruption to facilitate prosthetic restoration of a maxillary permanent lateral incisor and canine with poor restorability for a young patient. Restoration after orthodontic eruption presents a more conservative treatment choice in young patients compared with prosthetic restoration after extraction. On examination, the patient had root stumps in the region of 22 and 23. We decided to treat the patient by orthodontic extrusion followed by endodontic post and core. The case was treated with the help of 19 gauge wire and gold posts.

2.
J Pharm Bioallied Sci ; 16(Suppl 1): S993-S995, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38595632

RESUMO

Traumatic dental injuries (TDIs) have significant long-term consequences for the oral cavity's hard and soft tissues. Alveolar process fractures are particularly complicated. This case report describes the management and 12-month follow-up of a segmental maxillary alveolar process fracture involving laterally luxated primary incisors. A case of a 4-year-old boy was reported to the hospital 1 hour after an accidental fall at school, which resulted in a fracture of the maxillary alveolar process. Emergency treatment consisted of fracture reduction and repositioning of the primary incisors, followed by a semirigid splint between maxillary canines. The splints were removed at the end of week 4, and the affected primary incisors remained asymptomatic.

3.
Pediatr Cardiol ; 43(1): 244-246, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34453186

RESUMO

We present the cardiac CT images of 5-month infant with aorto-pulmonary window along with anomalous left coronary artery from pulmonary artery along with endoluminal views which help the surgeons in pre-planning of baffle orientation.


Assuntos
Artéria Coronária Esquerda Anormal , Anomalias dos Vasos Coronários , Anomalias dos Vasos Coronários/diagnóstico por imagem , Humanos , Lactente , Artéria Pulmonar/diagnóstico por imagem , Tomografia Computadorizada por Raios X
4.
J Med Chem ; 64(15): 11527-11542, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34260228

RESUMO

The orphan G-protein-coupled receptor GPR139 is highly expressed in the habenula, a small brain nucleus that has been linked to depression, schizophrenia (SCZ), and substance-use disorder. High-throughput screening and a medicinal chemistry structure-activity relationship strategy identified a novel series of potent and selective benzotriazinone-based GPR139 agonists. Herein, we describe the chemistry optimization that led to the discovery and validation of multiple potent and selective in vivo GPR139 agonist tool compounds, including our clinical candidate TAK-041, also known as NBI-1065846 (compound 56). The pharmacological characterization of these GPR139 agonists in vivo demonstrated GPR139-agonist-dependent modulation of habenula cell activity and revealed consistent in vivo efficacy to rescue social interaction deficits in the BALB/c mouse strain. The clinical GPR139 agonist TAK-041 is being explored as a novel drug to treat negative symptoms in SCZ.


Assuntos
Descoberta de Drogas , Proteínas do Tecido Nervoso/agonistas , Receptores Acoplados a Proteínas G/agonistas , Esquizofrenia/tratamento farmacológico , Animais , Linhagem Celular , Relação Dose-Resposta a Droga , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Estrutura Molecular , Proteínas do Tecido Nervoso/deficiência , Receptores Acoplados a Proteínas G/deficiência , Relação Estrutura-Atividade
5.
J Med Chem ; 64(14): 9875-9890, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-33861086

RESUMO

Parkinson's disease (PD) is a chronic and progressive movement disorder with the urgent unmet need for efficient symptomatic therapies with fewer side effects. GPR6 is an orphan G-protein coupled receptor (GPCR) with highly restricted expression in dopamine receptor D2-type medium spiny neurons (MSNs) of the indirect pathway, a striatal brain circuit which shows aberrant hyperactivity in PD patients. Potent and selective GPR6 inverse agonists (IAG) were developed starting from a low-potency screening hit (EC50 = 43 µM). Herein, we describe the multiple parameter optimization that led to the discovery of multiple nanomolar potent and selective GPR6 IAG, including our clinical compound CVN424. GPR6 IAG reversed haloperidol-induced catalepsy in rats and restored mobility in the bilateral 6-OHDA-lesioned rat PD model demonstrating that inhibition of GPR6 activity in vivo normalizes activity in basal ganglia circuitry and motor behavior. CVN424 is currently in clinical development to treat motor symptoms in Parkinson's disease.


Assuntos
Descoberta de Drogas , Fármacos Neuroprotetores/farmacologia , Doença de Parkinson/tratamento farmacológico , Receptores Acoplados a Proteínas G/agonistas , Animais , Relação Dose-Resposta a Droga , Feminino , Humanos , Estrutura Molecular , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/química , Doença de Parkinson/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores Acoplados a Proteínas G/metabolismo , Relação Estrutura-Atividade
6.
J Pharmacol Exp Ther ; 377(3): 407-416, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33795395

RESUMO

GPR6 is an orphan G-protein-coupled receptor that has enriched expression in the striatopallidal, indirect pathway and medium spiny neurons of the striatum. This pathway is greatly impacted by the loss of the nigro-striatal dopaminergic neurons in Parkinson disease, and modulating this neurocircuitry can be therapeutically beneficial. In this study, we describe the in vitro and in vivo pharmacological characterization of (R)-1-(2-(4-(2,4-difluorophenoxy)piperidin-1-yl)-3-((tetrahydrofuran-3-yl)amino)-7,8-dihydropyrido[3,4-b]pyrazin-6(5H)-yl)ethan-1-one (CVN424), a highly potent and selective small-molecule inverse agonist for GPR6 that is currently undergoing clinical evaluation. CVN424 is brain-penetrant and shows dose-dependent receptor occupancy that attained brain 50% of receptor occupancy at plasma concentrations of 6.0 and 7.4 ng/ml in mice and rats, respectively. Oral administration of CVN424 dose-dependently increases locomotor activity and reverses haloperidol-induced catalepsy. Furthermore, CVN424 restored mobility in bilateral 6-hydroxydopamine lesion model of Parkinson disease. The presence and localization of GPR6 in medium spiny neurons of striatum postmortem samples from both nondemented control and patients with Parkinson disease were confirmed at the level of both RNA (using Nuclear Enriched Transcript Sort sequencing) and protein. This body of work demonstrates that CVN424 is a potent, orally active, and brain-penetrant GPR6 inverse agonist that is effective in preclinical models and is a potential therapeutic for improving motor function in patients with Parkinson disease. SIGNIFICANCE STATEMENT: CVN424 represents a nondopaminergic novel drug for potential use in patients with Parkinson disease.


Assuntos
Corpo Estriado , Animais , Hormônios Esteroides Gonadais , Ratos
7.
PLoS Negl Trop Dis ; 14(2): e0007982, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32012162

RESUMO

BACKGROUND: Government of India is committed to eliminate measles and control rubella/congenital rubella syndrome (CRS) by 2020. In 2016, CRS surveillance was established in five sentinel sites. We analyzed surveillance data to describe the epidemiology of CRS in India. METHODOLOGY/PRINCIPAL FINDINGS: We used case definitions adapted from the WHO-recommended standards for CRS surveillance. Suspected patients underwent complete clinical examination including cardiovascular system, ophthalmic examination and assessment for hearing impairment. Sera were tested for presence of IgM and IgG antibodies against rubella. Of the 645 suspected CRS patients enrolled during two years, 137 (21.2%) were classified as laboratory confirmed CRS and 8 (1.2%) as congenital rubella infection. The median age of laboratory confirmed CRS infants was 3 months. Common clinical features among laboratory confirmed CRS patients included structural heart defects in 108 (78.8%), one or more eye signs (cataract, glaucoma, pigmentary retinopathy) in 82 (59.9%) and hearing impairment in 51. (38.6%) Thirty-three (24.1%) laboratory confirmed CRS patients died over a period of 2 years. Surveillance met the quality indicators in terms of adequacy of investigation, adequacy of sample collection for serological diagnosis as well as virological confirmation. CONCLUSIONS/SIGNIFICANCE: About one fifth suspected CRS patients were laboratory confirmed, indicating significance of rubella as a persistent public health problem in India. Continued surveillance will generate data to monitor the progress made by the rubella control program in the country.


Assuntos
Síndrome da Rubéola Congênita/epidemiologia , Adolescente , Adulto , Anticorpos Antivirais/sangue , Feminino , Humanos , Imunoglobulina M/sangue , Índia/epidemiologia , Lactente , Recém-Nascido , Masculino , Síndrome da Rubéola Congênita/sangue , Síndrome da Rubéola Congênita/diagnóstico , Síndrome da Rubéola Congênita/mortalidade , Vigilância de Evento Sentinela , Adulto Jovem
8.
Int J Neuropsychopharmacol ; 23(2): 96-107, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31689714

RESUMO

BACKGROUND: Faster off-rate competitive enzyme inhibitors are generally more sensitive than slower off-rate ones to binding inhibition by enzyme substrates. We previously reported that the cyclic adenosine monophosphate concentration in dopamine D1 receptor-expressing medium spiny neurons (D1-MSNs) may be higher than that in D2-MSNs. Consequently, compared with slower off-rate phosphodiesterase 10A inhibitors, faster off-rate ones comparably activated D2-MSNs but partially activated D1-MSNs. We further investigated the pharmacological profiles of phosphodiesterase 10A inhibitors with different off-rates. METHODS: Phosphodiesterase 10A inhibitors with slower (T-609) and faster (T-773) off-rates were used. D1- and D2-MSN activation was assessed by substance P and enkephalin mRNA induction, respectively, in rodents. Antipsychotic-like effects were evaluated by MK-801- and methamphetamine-induced hyperactivity and prepulse inhibition in rodents. Cognition was assessed by novel object recognition task and radial arm maze in rats. Prefrontal cortex activation was evaluated by c-Fos immunohistochemistry in rats. Gene translations in D1- and D2-MSNs were evaluated by translating ribosome affinity purification and RNA sequencing in mice. RESULTS: Compared with T-609, T-773 comparably activated D2-MSNs but partially activated D1-MSNs. Haloperidol (a D2 antagonist) and T-773, but not T-609, produced antipsychotic-like effects in all paradigms. T-773, but not T-609 or haloperidol, activated the prefrontal cortex and improved cognition. Overall gene translation patterns in D2-MSNs by all drugs and those in D1-MSNs by T-773 and T-609 were qualitatively similar. CONCLUSIONS: Differential pharmacological profiles among those drugs could be attributable to activation balance of D1- and D2-MSNs. The "balanced activation" of MSNs by faster off-rate phosphodiesterase 10A inhibitors may be favorable to treat schizophrenia.


Assuntos
Antipsicóticos/farmacologia , Corpo Estriado/efeitos dos fármacos , Neurônios GABAérgicos/efeitos dos fármacos , Aprendizagem em Labirinto/efeitos dos fármacos , Nootrópicos/farmacologia , Inibidores de Fosfodiesterase/farmacologia , Diester Fosfórico Hidrolases , Córtex Pré-Frontal/efeitos dos fármacos , Receptores de Dopamina D1/efeitos dos fármacos , Receptores de Dopamina D2/efeitos dos fármacos , Reconhecimento Psicológico/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Ratos , Ratos Long-Evans , Ratos Sprague-Dawley
9.
Adv Exp Med Biol ; 964: 133-152, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28315269

RESUMO

Sigma-1 receptors are molecular chaperones that may act as pathological mediators and targets for novel therapeutic applications in neurodegenerative diseases. Accumulating evidence indicates that sigma-1 ligands can either directly or indirectly modulate multiple neurodegenerative processes, including excitotoxicity, calcium dysregulation, mitochondrial and endoplasmic reticulum dysfunction, inflammation, and astrogliosis. In addition, sigma-1 ligands may act as disease-modifying agents in the treatment for central nervous system (CNS) diseases by promoting the activity of neurotrophic factors and neural plasticity. Here, we summarize their neuroprotective and neurorestorative effects in different animal models of acute brain injury and chronic neurodegenerative diseases, and highlight their potential role in mitigating disease. Notably, current data suggest that sigma-1 receptor dysfunction worsens disease progression, whereas enhancement amplifies pre-existing functional mechanisms of neuroprotection and/or restoration to slow disease progression. Collectively, the data support a model of the sigma-1 receptor as an amplifier of intracellular signaling, and suggest future clinical applications of sigma-1 ligands as part of multi-therapy approaches to treat neurodegenerative diseases.


Assuntos
Chaperonas Moleculares/farmacologia , Doenças Neurodegenerativas/metabolismo , Fármacos Neuroprotetores/farmacologia , Receptores sigma/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Humanos , Ligantes , Doenças Neurodegenerativas/tratamento farmacológico , Neuroproteção/efeitos dos fármacos , Receptor Sigma-1
10.
Eur J Pharmacol ; 743: 42-7, 2014 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-25261035

RESUMO

Sigma receptors comprise a unique family of proteins that have been implicated in the pathophysiology and treatment of many central nervous system disorders, consistent with their high level of expression in the brain and spinal cord. Mounting evidence indicate that targeting sigma receptors may be particularly beneficial in a number of neurodegenerative conditions including Alzheimer׳s disease, Parkinson׳s disease, stroke, methamphetamine neurotoxicity, Huntington׳s disease, amyotrophic lateral sclerosis, and retinal degeneration. In this perspective, a brief overview is given on sigma receptors, followed by a focus on common mechanisms of neurodegeneration that appear amenable to modulation by sigma receptor ligands to convey neuroprotective effects and/or restorative functions. Within each of the major mechanisms discussed herein, the neuroprotective effects of sigma ligands are summarized, and when known, the specific sigma receptor subtype(s) involved are identified. Together, the literature suggests sigma receptors may provide a novel target for combatting neurodegenerative diseases through both neuronal and glial mechanisms.


Assuntos
Doenças Neurodegenerativas/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Receptores sigma/metabolismo , Animais , Humanos , Ligantes
11.
Adv Pharmacol ; 69: 323-86, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24484982

RESUMO

Many psychostimulants, including cocaine and methamphetamine, interact with sigma (σ) receptors at physiologically relevant concentrations. The potential therapeutic relevance of this interaction is underscored by the ability to selectively target σ receptors to mitigate many behavioral and physiological effects of psychostimulants in animal and cell-based model systems. This chapter begins with an overview of these enigmatic proteins. Provocative preclinical data showing that σ ligands modulate an array of cocaine and methamphetamine effects are summarized, along with emerging areas of research. Together, the literature suggests targeting of σ receptors as an innovative option for combating undesired actions of psychostimulants through both neuronal and glial mechanisms.


Assuntos
Estimulantes do Sistema Nervoso Central/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Receptores sigma/metabolismo , Animais , Ensaios Clínicos como Assunto/métodos , Cocaína/metabolismo , Humanos , Metanfetamina/metabolismo , Opipramol/administração & dosagem , Opipramol/metabolismo , Ligação Proteica/fisiologia , Receptores sigma/agonistas , Receptores sigma/antagonistas & inibidores , Transtornos Relacionados ao Uso de Substâncias/tratamento farmacológico , Transtornos Relacionados ao Uso de Substâncias/metabolismo
12.
Eur J Pharmacol ; 724: 193-203, 2014 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-24380829

RESUMO

Exposure to high or repeated doses of methamphetamine can cause hyperthermia and neurotoxicity, which are thought to increase the risk of developing a variety of neurological conditions. Sigma receptor antagonism can prevent methamphetamine-induced hyperthermia and neurotoxicity, but the underlying cellular targets through which the neuroprotection is conveyed remain unknown. Differentiated NG108-15 cells were thus used as a model system to begin elucidating the neuroprotective mechanisms targeted by sigma receptor antagonists to mitigate the effects of methamphetamine. In differentiated NG108-15 cells, methamphetamine caused the generation of reactive oxygen/nitrogen species, an increase in PERK-mediated endoplasmic reticulum stress and the activation of caspase-3, -8 and -9, ultimately resulting in apoptosis at micromolar concentrations, and necrotic cell death at higher concentrations. The sigma receptor antagonist, 6-acetyl-3-(4-(4-(4-fluorophenyl)piperazin-1-yl)butyl)benzo[d]oxazol-2(3H)-one (SN79), attenuated methamphetamine-induced increases in reactive oxygen/nitrogen species, activation of caspase-3, -8 and -9 and accompanying cellular toxicity. In contrast, 1,3-di(2-tolyl)-guanidine (DTG), a sigma receptor agonist, shifted the dose response curve of methamphetamine-induced cell death towards the left. To probe the effect of temperature on neurotoxicity, NG108-15 cells maintained at an elevated temperature (40 °C) exhibited a significant and synergistic increase in cell death in response to methamphetamine, compared to cells maintained at a normal cell culture temperature (37 °C). SN79 attenuated the enhanced cell death observed in the methamphetamine-treated cells at 40 °C. Together, the data demonstrate that SN79 reduces methamphetamine-induced reactive oxygen/nitrogen species generation and caspase activation, thereby conveying neuroprotective effects against methamphetamine under regular and elevated temperature conditions.


Assuntos
Benzoxazóis/farmacologia , Metanfetamina/efeitos adversos , Fármacos Neuroprotetores/farmacologia , Piperazinas/farmacologia , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptores sigma/antagonistas & inibidores , Animais , Apoptose/efeitos dos fármacos , Caspases/metabolismo , Linhagem Celular Tumoral , Febre/metabolismo , Ligantes , Camundongos , Necrose/tratamento farmacológico , Necrose/metabolismo , eIF-2 Quinase/metabolismo
13.
Int J Neuropsychopharmacol ; 16(5): 1033-44, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22932447

RESUMO

Sigma (σ) receptors have recently been identified as potential targets for the development of novel therapeutics aimed at mitigating the effects of methamphetamine. Particularly, σ receptors are believed to mitigate some of the neurotoxic effects of methamphetamine through modulation of dopamine, dopamine transporters and body temperature. Furthermore, recent evidence suggests that targeting σ receptors may prevent cognitive impairments produced by methamphetamine. In the present study, an optimized σ receptor antagonist, AZ66, was evaluated against methamphetamine-induced neurotoxicity and cognitive dysfunction. AZ66 was found to be highly selective for σ receptors compared to 64 other sites tested. Pretreatment of male, Swiss Webster mice with i.p. dosing of AZ66 significantly attenuated methamphetamine-induced striatal dopamine depletions, striatal dopamine transporter reductions and hyperthermia. Additionally, neurotoxic dosing with methamphetamine caused significant memory impairment in the object recognition test, which was attenuated when animals were pretreated with AZ66; similar trends were observed in the step-through passive avoidance test. Taken together, these results suggest that targeting σ receptors may provide neuroprotection against the neurotoxicity and cognitive impairments produced by methamphetamine.


Assuntos
Benzotiazóis/uso terapêutico , Inibidores da Captação de Dopamina/toxicidade , Dopamina/metabolismo , Transtornos da Memória/tratamento farmacológico , Metanfetamina/toxicidade , Piperazinas/uso terapêutico , Análise de Variância , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Temperatura Corporal/efeitos dos fármacos , Modelos Animais de Doenças , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Masculino , Transtornos da Memória/etiologia , Camundongos , Síndromes Neurotóxicas/complicações , Síndromes Neurotóxicas/etiologia , Neurotransmissores/farmacocinética , Ligação Proteica/efeitos dos fármacos , Receptores sigma/antagonistas & inibidores , Reconhecimento Psicológico/efeitos dos fármacos , Trítio/farmacocinética
14.
Eur Neuropsychopharmacol ; 23(8): 960-71, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22921523

RESUMO

Methamphetamine is a highly addictive psychostimulant drug of abuse, causing hyperthermia and neurotoxicity at high doses. Currently, there is no clinically proven pharmacotherapy to treat these effects of methamphetamine, necessitating identification of potential novel therapeutic targets. Earlier studies showed that methamphetamine binds to sigma (σ) receptors in the brain at physiologically relevant concentrations, where it "acts in part as an agonist." SN79 (6-acetyl-3-(4-(4-(4-florophenyl)piperazin-1-yl)butyl)benzo[d]oxazol-2(3H)-one) was synthesized as a putative σ receptor antagonist with nanomolar affinity and selectivity for σ receptors over 57 other binding sites. SN79 pretreatment afforded protection against methamphetamine-induced hyperthermia and striatal dopaminergic and serotonergic neurotoxicity in male, Swiss Webster mice (measured as depletions in striatal dopamine and serotonin levels, and reductions in striatal dopamine and serotonin transporter expression levels). In contrast, di-o-tolylguanidine (DTG), a well established σ receptor agonist, increased the lethal effects of methamphetamine, although it did not further exacerbate methamphetamine-induced hyperthermia. Together, the data implicate σ receptors in the direct modulation of some effects of methamphetamine such as lethality, while having a modulatory role which can mitigate other methamphetamine-induced effects such as hyperthermia and neurotoxicity.


Assuntos
Benzoxazóis/uso terapêutico , Estimulantes do Sistema Nervoso Central/toxicidade , Metanfetamina/toxicidade , Proteínas do Tecido Nervoso/antagonistas & inibidores , Fármacos Neuroprotetores/uso terapêutico , Síndromes Neurotóxicas/prevenção & controle , Piperazinas/uso terapêutico , Receptores sigma/antagonistas & inibidores , Animais , Benzoxazóis/efeitos adversos , Estimulantes do Sistema Nervoso Central/antagonistas & inibidores , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Corpo Estriado/patologia , Dopamina/química , Dopamina/metabolismo , Antagonistas de Dopamina/efeitos adversos , Antagonistas de Dopamina/uso terapêutico , Proteínas da Membrana Plasmática de Transporte de Dopamina/antagonistas & inibidores , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Sinergismo Farmacológico , Febre/etiologia , Febre/prevenção & controle , Guanidinas/efeitos adversos , Guanidinas/uso terapêutico , Masculino , Metanfetamina/antagonistas & inibidores , Camundongos , Proteínas do Tecido Nervoso/agonistas , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Fármacos Neuroprotetores/efeitos adversos , Síndromes Neurotóxicas/metabolismo , Síndromes Neurotóxicas/patologia , Síndromes Neurotóxicas/fisiopatologia , Piperazinas/efeitos adversos , Distribuição Aleatória , Receptores sigma/agonistas , Serotonina/química , Serotonina/metabolismo , Antagonistas da Serotonina/efeitos adversos , Antagonistas da Serotonina/uso terapêutico , Proteínas da Membrana Plasmática de Transporte de Serotonina/química , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo
15.
Mol Pharmacol ; 81(3): 299-308, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22101517

RESUMO

Methamphetamine is a highly addictive psychostimulant drug of abuse that causes neurotoxicity with high or repeated dosing. Earlier studies demonstrated the ability of the selective σ receptor ligand N-phenethylpiperidine oxalate (AC927) to attenuate the neurotoxic effects of methamphetamine in vivo. However, the precise mechanisms through which AC927 conveys its protective effects remain to be determined. With the use of differentiated NG108-15 cells as a model system, the effects of methamphetamine on neurotoxic endpoints and mediators such as apoptosis, necrosis, generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS), and dopamine release were examined in the absence and presence of AC927. Methamphetamine at physiologically relevant micromolar concentrations caused apoptosis in NG108-15 cells. At higher concentrations of methamphetamine, necrotic cell death was observed. At earlier time points, methamphetamine caused ROS/RNS generation, which was detected with the fluorigenic substrate 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescin diacetate, acetyl ester, in a concentration- and time-dependent manner. N-Acetylcysteine, catalase, and l-N(G)-monomethyl arginine citrate inhibited the ROS/RNS fluorescence signal induced by methamphetamine, which suggests the formation of hydrogen peroxide and RNS. Exposure to methamphetamine also stimulated the release of dopamine from NG108-15 cells into the culture medium. AC927 attenuated methamphetamine-induced apoptosis, necrosis, ROS/RNS generation, and dopamine release in NG108-15 cells. Together, the data suggest that modulation of σ receptors can mitigate methamphetamine-induced cytotoxicity, ROS/RNS generation, and dopamine release in cultured cells.


Assuntos
Dopamina/metabolismo , Metanfetamina/antagonistas & inibidores , Oxalatos/farmacologia , Piperidinas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Receptores sigma/agonistas , Apoptose , Linhagem Celular Tumoral , Citometria de Fluxo , Humanos , Metanfetamina/farmacologia , Espécies Reativas de Nitrogênio/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptores sigma/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismo
16.
Curr Neuropharmacol ; 9(1): 54-7, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21886562

RESUMO

Methamphetamine (METH) is a widely abused substance world over. Currently, there is no effective pharmacotherapy to treat its effects. This necessitates identification of potential novel therapeutic targets. METH interacts with sigma (σ) receptors at physiologically relevant micromolar concentrations. In addition, σ receptors are present in organs like the brain, heart, and lungs at which METH acts. Additionally, σ receptors have been implicated in various acute and subchronic effects like locomotor stimulation, development of sensitization and neurotoxicity, where σ receptor antagonists attenuate these effects. σ Receptors may also have a role in METH-induced psychiatric complications such as depression, psychosis, cognitive and motor deficits. The neurotoxic effects of METH, which are cause for concern, can be prevented by σ receptor antagonists in mice. Mechanistically, METH-induced neurotoxicity involves factors like dopamine release, oxidative stress, endoplasmic reticulum stress, activation of mitochondrial death cascades, glutamate release, apoptosis, microglial activation, and hyperthermia. This review compiles studies from the literature that suggests an important role for σ receptors in many of the mechanisms of METH-induced neurotoxicity.

17.
Neuropharmacology ; 61(5-6): 992-1000, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21762711

RESUMO

Methamphetamine (METH) is a highly addictive psychostimulant drug of abuse. Low and high dose administration of METH leads to locomotor stimulation, and dopaminergic and serotonergic neurotoxicity, respectively. The behavioral stimulant and neurotoxic effects of METH can contribute to addiction and other neuropsychiatric disorders, thus necessitating the identification of potential pharmacotherapeutics against these effects produced by METH. METH binds to σ receptors at physiologically relevant concentrations. Also, σ receptors are present on and can modulate dopaminergic and serotonergic neurons. Therefore, σ receptors provide a viable target for the development of pharmacotherapeutics against the adverse effects of METH. In the present study, CM156, a σ receptor ligand with high affinity and selectivity for σ receptors over 80 other non-σ binding sites, was evaluated against METH-induced stimulant, hyperthermic, and neurotoxic effects. Pretreatment of male, Swiss Webster mice with CM156 dose dependently attenuated the locomotor stimulation, hyperthermia, striatal dopamine and serotonin depletions, and striatal dopamine and serotonin transporter reductions produced by METH, without significant effects of CM156 on its own. These results demonstrate the ability of a highly selective σ ligand to mitigate the effects of METH.


Assuntos
Estimulantes do Sistema Nervoso Central/toxicidade , Metanfetamina/toxicidade , Síndromes Neurotóxicas/tratamento farmacológico , Síndromes Neurotóxicas/patologia , Piperazinas/farmacologia , Substâncias Protetoras/farmacologia , Receptores sigma/antagonistas & inibidores , Compostos de Enxofre/farmacologia , Animais , Temperatura Corporal/efeitos dos fármacos , Estimulantes do Sistema Nervoso Central/farmacologia , Cocaína/antagonistas & inibidores , Dopamina/análise , Avaliação Pré-Clínica de Medicamentos , Febre/induzido quimicamente , Febre/metabolismo , Masculino , Metanfetamina/farmacologia , Camundongos , Terapia de Alvo Molecular , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Síndromes Neurotóxicas/metabolismo , Piperazinas/uso terapêutico , Substâncias Protetoras/uso terapêutico , Receptores sigma/metabolismo , Serotonina/análise , Proteínas da Membrana Plasmática de Transporte de Serotonina/análise , Proteínas da Membrana Plasmática de Transporte de Serotonina/efeitos dos fármacos , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Compostos de Enxofre/uso terapêutico
18.
AAPS J ; 13(3): 336-46, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21494909

RESUMO

Cocaine interacts with monoamine transporters and sigma (σ) receptors, providing logical targets for medication development. In the present study, in vitro and in vivo pharmacological studies were conducted to characterize SN79, a novel compound which was evaluated for cocaine antagonist actions. Radioligand binding studies showed that SN79 had a nanomolar affinity for σ receptors and a notable affinity for 5-HT(2) receptors, and monoamine transporters. It did not inhibit major cytochrome P450 enzymes, including CYP1A2, CYP2A6, CYP2C19, CYP2C9*1, CYP2D6, and CYP3A4, suggesting a low propensity for potential drug-drug interactions. Oral administration of SN79 reached peak in vivo concentrations after 1.5 h and exhibited a half-life of just over 7.5 h in male, Sprague-Dawley rats. Behavioral studies conducted in male, Swiss Webster mice, intraperitoneal or oral dosing with SN79 prior to a convulsive or locomotor stimulant dose of cocaine led to a significant attenuation of cocaine-induced convulsions and locomotor activity. However, SN79 produced sedation and motor incoordination on its own at higher doses, to which animals became tolerant with repeated administration. SN79 also significantly attenuated the development and expression of the sensitized response to repeated cocaine exposures. The ability of SN79 to significantly attenuate the acute and subchronic effects of cocaine provides a promising compound lead to the development of an effective pharmacotherapy against cocaine.


Assuntos
Benzoxazóis/síntese química , Benzoxazóis/farmacologia , Cocaína/antagonistas & inibidores , Piperazinas/síntese química , Piperazinas/farmacologia , Administração Oral , Animais , Benzoxazóis/química , Benzoxazóis/farmacocinética , Cocaína/toxicidade , Sistema Enzimático do Citocromo P-450/metabolismo , Interações Medicamentosas , Meia-Vida , Injeções Intraperitoneais , Ligantes , Masculino , Camundongos , Atividade Motora/efeitos dos fármacos , Piperazinas/química , Piperazinas/farmacocinética , Ligação Proteica , Ensaio Radioligante , Ratos , Ratos Sprague-Dawley , Receptores 5-HT2 de Serotonina/metabolismo , Receptores sigma/metabolismo , Convulsões/induzido quimicamente , Convulsões/prevenção & controle
19.
Pharmacol Biochem Behav ; 98(1): 12-20, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21130800

RESUMO

Methamphetamine interacts with sigma (σ) receptors and AC927, a selective σ receptor ligand, protects against methamphetamine-induced dopaminergic neurotoxicity. In the present study, the effects of AC927 on methamphetamine-induced hyperthermia and striatal serotonergic neurotoxicity were evaluated. Male, Swiss Webster mice were injected (i.p.) every 2 h, for a total of four times, with one of the following treatments: Saline+Saline; Saline+Methamphetamine (5 mg/kg); AC927 (5, 10, 20 mg/kg)+Methamphetamine (5 mg/kg); or AC927 (5, 10, 20 mg/kg)+Saline. Pretreatment with AC927 (10 mg/kg) significantly attenuated methamphetamine-induced striatal serotonin depletions, striatal serotonin transporter reductions, and hyperthermia. At the doses tested, AC927 itself had no significant effects on serotonin levels, serotonin transporter expression, or body temperature. To evaluate the effects of higher ambient temperature on methamphetamine-induced neurotoxicity, groups of mice were treated at 37 °C. Overall, there was an inverse correlation between the body temperature of the animals and striatal serotonin levels. Together, the data suggest that AC927 (10 mg/kg) protects against methamphetamine-induced neurotoxicity. The reduction of methamphetamine-induced hyperthermia by AC927 may contribute to the observed neuroprotection in vivo.


Assuntos
Febre/induzido quimicamente , Febre/prevenção & controle , Metanfetamina/toxicidade , Oxalatos/metabolismo , Oxalatos/farmacologia , Piperidinas/metabolismo , Piperidinas/farmacologia , Receptores sigma/metabolismo , Animais , Temperatura Corporal/efeitos dos fármacos , Temperatura Corporal/fisiologia , Febre/metabolismo , Ligantes , Masculino , Camundongos , Fármacos Neuroprotetores/metabolismo , Fármacos Neuroprotetores/farmacologia , Serotonina/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Córtex Visual/efeitos dos fármacos , Córtex Visual/metabolismo , Córtex Visual/patologia
20.
J Pharmacol Exp Ther ; 333(2): 491-500, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20100904

RESUMO

Cocaine is a highly abused drug without effective pharmacotherapies to treat it. It interacts with sigma (sigma) receptors, providing logical targets for the development of medications to counteract its actions. Cocaine causes toxic and stimulant effects that can be categorized as acute effects such as convulsions and locomotor hyperactivity and subchronic effects including sensitization and place conditioning. In the present study, 3-(4-(4-cyclohexylpiperazin-1-yl)butyl)benzo[d]thiazole-2(3H)-thione (CM156), a novel compound, was developed and tested for interactions with sigma receptors using radioligand binding studies. It was also evaluated against cocaine-induced effects in behavioral studies. The results showed that CM156 has nanomolar affinities for each of the sigma receptor subtypes in the brain and much weaker affinities for non-sigma binding sites. Pretreatment of male Swiss-Webster mice with CM156, before administering either a convulsive or locomotor stimulant dose of cocaine, led to a significant attenuation of these acute effects. CM156 also significantly reduced the expression of behavioral sensitization and place conditioning evoked by subchronic exposure to cocaine. The protective effects of CM156 are consistent with sigma receptor-mediated actions. Together with previously reported findings, the data from CM156 and related sigma compounds indicate that sigma receptors can be targeted to alleviate deleterious actions of cocaine.


Assuntos
Cocaína/antagonistas & inibidores , Piperazinas/farmacologia , Compostos de Enxofre/farmacologia , Animais , Ligação Competitiva/efeitos dos fármacos , Cocaína/farmacologia , Relação Dose-Resposta a Droga , Masculino , Camundongos , Microssomos Hepáticos/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Receptores sigma/efeitos dos fármacos , Convulsões/induzido quimicamente , Convulsões/prevenção & controle
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