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1.
ChemMedChem ; 15(23): 2273-2279, 2020 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-32827245

RESUMO

Anaerobic choline metabolism by human gut microbiota to produce trimethylamine (TMA) has recently evolved as a potential therapeutic target because of its association with chronic kidney disease and increased cardiovascular risks. Limited examples of choline analogues have been reported as inhibitors of bacterial enzyme choline TMA-lyase (CutC), a key enzyme regulating choline anaerobic metabolism. We used a new workflow to discover CutC inhibitors based on focused screening of a diversified library of small molecules for intestinal metabolic stability followed by in vitro CutC inhibitory assay. This workflow identified a histidine-based scaffold as a CutC inhibitor with an IC50 value of 1.9±0.2 µM. Remarkably, the identified CutC inhibitor was able to reduce the production of TMA in whole-cell assays using various bacterial strains as well as in complex gut microbiota environment. The improved efficiency of the new scaffold identified in this study in comparison to previously reported CutC inhibitors would enable optimization of potential leads for in vivo screening and clinical translation. Finally, docking studies and molecular-dynamic simulations were used to predict putative interactions created between inhibitor and CutC.


Assuntos
Colina/antagonistas & inibidores , Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Histidina/farmacologia , Liases/antagonistas & inibidores , Metilaminas/antagonistas & inibidores , Colina/metabolismo , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Histidina/química , Humanos , Liases/metabolismo , Metilaminas/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular
2.
Adv Pharmacol ; 89: 357-386, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32616213

RESUMO

Scopolamine is a nonselective muscarinic antagonist that has shown relatively rapid antidepressant effects, although to date the results are from limited clinical studies. Scopolamine reportedly has downstream signaling effects thought to be linked to neuroplasticity within glutamatergic synapses and consequent antidepressant action. In psychiatry, clinically validated pathways are unusual and thus merit further research in an effort develop more effect medicines for patients with mood disorders. Thus, we are faced with a unique opportunity to build on the clinical observation associated with scopolamine through reverse translation to identify of targets that retain the clinical efficacy while reducing the side effect profile. This chapter reviews the clinical antidepressant findings with scopolamine, including discussion of differential response across patient subgroups, as well as a review of biomarkers that predict clinical outcome. The preclinical data associated with scopolamine also are reviewed and convey a vision for narrowing in on the therapeutic muscarinic receptor subtype(s) that support the antidepressant effects to guide the development of next generation antimuscarinic drug targets for depression.


Assuntos
Antidepressivos/uso terapêutico , Antagonistas Muscarínicos/uso terapêutico , Escopolamina/uso terapêutico , Animais , Colina/antagonistas & inibidores , Depressão/tratamento farmacológico , Humanos , Escopolamina/efeitos adversos , Resultado do Tratamento
3.
Bull Exp Biol Med ; 168(2): 193-198, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31776959

RESUMO

Stimulation of the serotoninergic system (5-hydroxytryptophan, 50 mg/kg; fluoxetine, 3 mg/kg) induced a significant increase in HR and a reduction in the amplitude of all waves of the heart rhythm variability. Stimulation of the dopaminergic system (L-DOPA and amantadine, 20 mg/kg each) resulted in a moderate increase in HR and amplitudes of low-frequency (LF) and very-low-frequency (VLF) waves of the heart rhythm variability. Successive blockade of nicotinic (hexamethonium, 7 mg/kg) and muscarinic cholinergic receptors (atropine, 1 mg/kg) leads to a significant decrease in the variability of cardiointervals (almost to complete levelling) both under control conditions and after stimulation of the neurotransmitter systems. Serotonin receptor blockade (promethazine, 2 mg/kg) did not affect HR, but reduced the amplitude of LF- and VLF-waves. Under conditions of serotoninergic system stimulation, the blockade of serotonin receptors was followed by a significant HR acceleration without changes in heart rhythm variability; blockade of dopamine receptors (sulpiride, 1 mg/kg) induced HR acceleration and increase in the amplitude of LF- and VLF-waves; blockade of dopamine receptors under conditions of dopamine system stimulation was followed by a significant increase in HR and a decrease in the amplitude of all waves of the heart rhythm variability. It can be hypothesized that serotonin- and dopaminergic systems affect the heart rhythm via cardiomyocyte receptors and via modulation of activity of the adrenergic and cholinergic systems. The effects of serotonin- and dopaminergic systems can be considered as synergic in the CNS, and antagonistic at the periphery.


Assuntos
Neurônios Dopaminérgicos/fisiologia , Frequência Cardíaca/efeitos dos fármacos , Neurotransmissores/farmacologia , Receptores de Neurotransmissores/efeitos dos fármacos , Neurônios Serotoninérgicos/fisiologia , Animais , Colina/antagonistas & inibidores , Agonistas de Dopamina/farmacologia , Antagonistas de Dopamina/farmacologia , Neurônios Dopaminérgicos/efeitos dos fármacos , Frequência Cardíaca/fisiologia , Masculino , Agonistas Muscarínicos/farmacologia , Antagonistas Muscarínicos/farmacologia , Ratos , Receptores Dopaminérgicos/metabolismo , Receptores Muscarínicos/metabolismo , Receptores de Serotonina/metabolismo , Neurônios Serotoninérgicos/efeitos dos fármacos , Serotonina/metabolismo , Antagonistas da Serotonina/farmacologia , Agonistas do Receptor de Serotonina/farmacologia
4.
Biochem Biophys Res Commun ; 519(3): 540-546, 2019 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-31537380

RESUMO

1-Methyl-4-phenylpyridinium (MPP+)-treated human neuroblastoma SH-SY5Y cells have been generally accepted as a cellular model for Parkinson's disease. To understand comprehensive metabolic disturbances in this model, both cell lysates and culture supernatants were subjected to metabolomic analysis. As expected from the fact that MPP+ inhibits mitochondrial complex I, a metabolic shift from mitochondrial oxidative phosphorylation to glycolysis was indicated by an increase in extracellular lactic acid and a parallel depletion of pyruvic acid. In cell lysates, the metabolic shift was supported by consistent decreases in TCA cycle intermediates. Metabolomic analysis also revealed aberrant choline metabolism. Choline in the culture supernatant was elevated 8.5- and 17-fold by 30 and 300 µM MPP+ exposure, respectively; therefore, extracellular choline might be a metabolic biomarker for Parkinson's disease.


Assuntos
1-Metil-4-fenilpiridínio/farmacologia , Colina/antagonistas & inibidores , Metabolômica , Mitocôndrias/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Colina/metabolismo , Relação Dose-Resposta a Droga , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/metabolismo , Relação Estrutura-Atividade , Células Tumorais Cultivadas
5.
J Pharm Biomed Anal ; 159: 100-112, 2018 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-29980011

RESUMO

Gut microbiota based metabolism of choline produces trimethylamine (TMA) which is further converted to a pro-atherosclerotic metabolite, trimethylamine-N-oxide (TMAO) by flavin monooxygenase (FMO3). Trigonelline from the plant Trigonella foenum-graecum has been reported for the treatment of CVD. Aim of the present study was to check the effect of trigonelline on the gut microbiota based conversion of TMA to TMAO. Trigonelline was isolated from hydroalcoholic extract of seeds of Trigonella foenum-graecum. The isolated trigonelline was characterized through TLC and UPLC-MS. Anaerobic microbe responsible for the metabolism of choline to TMA was isolated by culturing the human gut microbiota in choline enriched medium. The isolated bacteria was identified at molecular level based on PCR amplification of 1500bp of 16S rRNA gene sequence. Isolated FMO3 was used for ex vivo conversion of TMA to TMAO. Further, we investigated the effect of trigonelline in isolated gut microbe based metabolism of choline, lipid profile and TMAO levels in mice with or without suppression of gut microbiota with antibiotics. Liquid-liquid purification and chromatographic analysis confirmed the trigonelline purity (87.26%) and which was also confirmed by mass spectroscopy with m/z 137.4 in positive ionization mode. A total of 30 anaerobic microbes responsible for TMA production were isolated and Citrobacter freundii was the superior among others for the production of TMA. In vitro culture of C. freundii in choline enriched medium supplemented with trigonelline resulted in significantly reduction TMA and followed by TMAO production. In ex vivo, a maximum of 85.3% TMAO production was reduced by trigonelline at concentration of about 300 µg/mL. Serum level of lipids and TMAO were significantly altered in choline fed animals with or without suppression of gut microbiota and this phenomenon was reversed upon the oral administration of trigonelline in a dose-dependent manner. This study demonstrates the effect of trigonelline on gut microbiota responsible for choline metabolism and this can be used as a model for evaluation of herbal drugs and its effect in gut microbiota prompted cardiovascular disorders.


Assuntos
Alcaloides/farmacologia , Doenças Cardiovasculares/metabolismo , Doenças Cardiovasculares/prevenção & controle , Colina/antagonistas & inibidores , Colina/metabolismo , Microbioma Gastrointestinal/efeitos dos fármacos , Adulto , Animais , Doenças Cardiovasculares/patologia , Feminino , Microbioma Gastrointestinal/fisiologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Filogenia , Distribuição Aleatória , Fatores de Risco
6.
Neurochem Int ; 108: 410-416, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28577989

RESUMO

The synaptic uptake of choline via the high-affinity, hemicholinium-3-dependent choline transporter (CHT) strongly influences the capacity of cholinergic neurons to sustain acetylcholine (ACh) synthesis and release. To advance research on the impact of CHT capacity in humans, we established the presence of the neuronal CHT protein in human T lymphocytes. Next, we demonstrated CHT-mediated choline transport in human T cells. To address the validity of T cell-based choline uptake as a proxy for brain CHT capacity, we isolated T cells from the spleen, and synaptosomes from cortex and striatum, of wild type and CHT-overexpressing mice (CHT-OXP). Choline uptake capacity in T cells from CHT-OXP mice was two-fold higher than in wild type mice, mirroring the impact of CHT over-expression on synaptosomal CHT-mediated choline uptake. Monitoring T lymphocyte CHT protein and activity may be useful for estimating human CNS cholinergic capacity and for testing hypotheses concerning the contribution of CHT and, more generally, ACh signaling in cognition, neuroinflammation and disease.


Assuntos
Encéfalo/metabolismo , Colina/metabolismo , Hemicolínio 3/farmacologia , Proteínas de Membrana Transportadoras/metabolismo , Linfócitos T/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/fisiologia , Encéfalo/efeitos dos fármacos , Colina/antagonistas & inibidores , Relação Dose-Resposta a Droga , Feminino , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Linfócitos T/efeitos dos fármacos
7.
Artigo em Inglês | MEDLINE | ID: mdl-28188896

RESUMO

The extensive use of copper oxide nanoparticles (CuO NPs) in many applications has raised concerns over their toxicity on environment and human health. Herein, the embryotoxicity of CuO NPs was assessed in the black sea urchin Arbacia lixula, an intertidal species commonly present in the Mediterranean. Fertilized eggs were exposed to 0.7, 10 and 20ppb of CuO NPs, until pluteus stage. Interferences with the normal neurotransmission pathways were observed in sea urchin embryos. In detail, evidence of cholinergic and serotoninergic systems affection was revealed by dose-dependent decreased levels of choline and N-acetyl serotonin, respectively, measured by nuclear magnetic resonance (NMR)-based metabolomics, applied for the first time to our knowledge on sea urchin embryos. The metabolic profile also highlighted a significant CuO NP dose-dependent increase of glycine, a component of matrix proteins involved in the biomineralization process, suggesting perturbed skeletogenesis accordingly to skeletal defects in spicule patterning observed previously in the same sea urchin embryos. However, the expression of skeletogenic genes, i.e. SM30 and msp130, did not differ among groups, and therefore altered primary mesenchyme cell (PMC) migration was hypothesized. Other unknown metabolites were detected from the NMR spectra, and their concentrations found to be reflective of the CuO NP exposure levels. Overall, these findings demonstrate the toxic potential of CuO NPs to interfere with neurotransmission and skeletogenesis of sea urchin embryos. The integrated use of embryotoxicity tests and metabolomics represents a highly sensitive and effective tool for assessing the impact of NPs on aquatic biota.


Assuntos
Arbacia/efeitos dos fármacos , Cobre/toxicidade , Nanopartículas Metálicas/toxicidade , Morfogênese/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Zigoto/efeitos dos fármacos , Exoesqueleto/efeitos dos fármacos , Exoesqueleto/crescimento & desenvolvimento , Animais , Arbacia/citologia , Arbacia/crescimento & desenvolvimento , Arbacia/fisiologia , Colina/antagonistas & inibidores , Colina/metabolismo , Neurônios Colinérgicos/citologia , Neurônios Colinérgicos/efeitos dos fármacos , Neurônios Colinérgicos/metabolismo , Cobre/química , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Glicina/agonistas , Glicina/metabolismo , Espectroscopia de Ressonância Magnética , Mar Mediterrâneo , Metabolômica/métodos , Nanopartículas Metálicas/química , Neurônios Serotoninérgicos/citologia , Neurônios Serotoninérgicos/efeitos dos fármacos , Serotonina/análogos & derivados , Serotonina/química , Serotonina/metabolismo , Sicília , Propriedades de Superfície , Teratogênicos/toxicidade , Poluentes Químicos da Água/química , Zigoto/citologia , Zigoto/crescimento & desenvolvimento
8.
Pharm Biol ; 54(12): 3169-3171, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27564011

RESUMO

CONTEXT: Thr6-bradykinin is a peptide found in the venom of social and solitary wasps. This kinin, along with other bradykinin-like peptides, is known to cause irreversible paralysis in insects by presynaptic blockade of cholinergic transmission. However, this activity has never been tested in mammals. OBJECTIVE: As such, the objective of this study was to evaluate the effect of Thr6-bradykinin on the cholinergic system of rats. MATERIALS AND METHODS: The peptide was isolated from the venom of the Neotropical social wasp Polybia occidentalis Olivier (Vespidae). After correct identification and quantification by ESI-MS and MS/MS, the peptide was tested in [14C]-choline uptake using rat cortical synaptosomes. Each uptake assay was accompanied by lactic acid dehydrogenase (LDH) activity measurement to evaluate synaptosome integrity in the presence of six increasing concentrations of BK or Thr6-BK (0.039, 0.156, 0.625, 2.500, 10.000 and 40.000 µM). RESULTS: Data revealed that neither BK nor Thr6-BK at any of the six concentrations tested (from 0.039 to 40.000 µM) affected [14C]-choline uptake in synaptosomes. Moreover, there was no increase in LDH in the supernatants, indicating that BK and Thr6-BK did not disrupt the synaptosomes. DISCUSSION AND CONCLUSION: In contrast to previous reports for the insect central nervous system (CNS), Thr6-BK had no effect on mammalian cholinergic transmission. Nevertheless, this selectivity for the insect CNS, combined with its irreversible mode of action may be relevant to the discovery of new sources of insecticides and could contribute to understanding the role of kinins in the mammalian CNS.


Assuntos
Bradicinina/metabolismo , Córtex Cerebral/metabolismo , Colina/metabolismo , Venenos de Vespas/metabolismo , Animais , Bradicinina/isolamento & purificação , Bradicinina/farmacologia , Radioisótopos de Carbono/metabolismo , Córtex Cerebral/efeitos dos fármacos , Colina/antagonistas & inibidores , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos/métodos , Masculino , Ratos , Ratos Wistar , Venenos de Vespas/isolamento & purificação , Venenos de Vespas/farmacologia , Vespas
9.
J Recept Signal Transduct Res ; 31(1): 39-44, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20863173

RESUMO

The present work was carried out to determine the effects of lyophilized seed extracts of Psoralea corylifolia along with pure psoralen, its active ingredient on the isolated tail-piece melanophores of Bufo melanostictus, a type of disguised smooth muscle cells, which offer excellent in vitro opportunities for studying the effects of pharmacological and pharmaceutical agents. In the present study, it was found that lyophilized extract of P. corylifolia and its active ingredient psoralen induced powerful, dose-dependent, physiologically significant melanin dispersal effects in the isolated tail melanophores of B. melanostictus, which were completely blocked by atropine as well as hyoscine. The per se melanin dispersal effects of lyophilized extracts of P. corylifolia and its active ingredient psoralen were highly potentiated by neostigmine. It appears that the melanin dispersal effects of the extracts of P. corylifolia and psoralen are mediated by cholino-muscarinic or cholino-psoralen like receptors having similar properties that need to be studied further.


Assuntos
Colina/metabolismo , Melanóforos/metabolismo , Extratos Vegetais/farmacologia , Psoralea/química , Receptores de Superfície Celular/metabolismo , Pigmentação da Pele/efeitos dos fármacos , Cauda/citologia , Animais , Atropina/farmacologia , Bufonidae , Separação Celular , Colina/antagonistas & inibidores , Liofilização , Larva/efeitos dos fármacos , Larva/metabolismo , Melanóforos/efeitos dos fármacos , Neostigmina/farmacologia , Escopolamina/farmacologia , Sementes/química
10.
Food Chem Toxicol ; 48(3): 798-802, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20034530

RESUMO

Recently, numerous medicinal plants possessing profound central nervous system effects and antioxidant activity have received much attention as food supplement to improve cognitive function against cognitive deficit condition including in Alzheimer's disease condition. Based on this information, the effect of piperine, a main active alkaloid in fruit of Piper nigrum, on memory performance and neurodegeneration in animal model of Alzheimer's disease have been investigated. Adult male Wistar rats (180-220 g) were orally given piperine at various doses ranging from 5, 10 and 20mg/kg BW at a period of 2 weeks before and 1 week after the intracerebroventricular administration of ethylcholine aziridinium ion (AF64A) bilaterally. The results showed that piperine at all dosage range used in this study significantly improved memory impairment and neurodegeneration in hippocampus. The possible underlying mechanisms might be partly associated with the decrease lipid peroxidation and acetylcholinesterase enzyme. Moreover, piperine also demonstrated the neurotrophic effect in hippocampus. However, further researches about the precise underlying mechanism are still required.


Assuntos
Alcaloides/farmacologia , Doença de Alzheimer/patologia , Benzodioxóis/farmacologia , Transtornos Cognitivos/prevenção & controle , Degeneração Neural/prevenção & controle , Fármacos Neuroprotetores , Piper nigrum/química , Piperidinas/farmacologia , Alcamidas Poli-Insaturadas/farmacologia , Acetilcolinesterase/metabolismo , Doença de Alzheimer/psicologia , Animais , Aziridinas/antagonistas & inibidores , Aziridinas/toxicidade , Colina/análogos & derivados , Colina/antagonistas & inibidores , Colina/toxicidade , Transtornos Cognitivos/patologia , Transtornos Cognitivos/psicologia , Donepezila , Hipocampo/patologia , Indanos/farmacologia , Injeções Intraventriculares , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Malondialdeído/metabolismo , Aprendizagem em Labirinto , Degeneração Neural/patologia , Degeneração Neural/psicologia , Bloqueadores Neuromusculares/antagonistas & inibidores , Bloqueadores Neuromusculares/toxicidade , Nootrópicos/farmacologia , Ratos , Percepção Espacial/efeitos dos fármacos , Tailândia
11.
Brain Res ; 1297: 9-16, 2009 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-19729002

RESUMO

In this study, we show that pretreatment with physiological concentrations (1-100 nM) of 17beta-estradiol decreased apoptosis induced by ethylcholine aziridinium (AF64A), a choline toxin, in the cholinergic neuronal cell line NG108-15. These protective effects were observed after short-term (30 min) pretreatment, and were blocked by treatment with an estrogen receptor antagonist and inhibitors of phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase kinase (MEK). The protective effects were, however, not reversed by a protein synthesis inhibitor. Furthermore, we examined the effects of 17beta-estradiol on choline uptake in NG108-15 cells. Although choline uptake was inhibited by a selective inhibitor of choline uptake, hemicholinium-3, it was not altered by treatment with 17beta-estradiol. These results indicated that the protective effect of 17beta-estradiol on AF64A-induced apoptosis could be nongenomic, and that this effect may be due to the activation of PI3K/Akt and/or MEK/extracellular signal-regulated kinase (ERK) pathways.


Assuntos
Apoptose/efeitos dos fármacos , Aziridinas/antagonistas & inibidores , Colina/análogos & derivados , Estradiol/farmacologia , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Acetilcolina/metabolismo , Animais , Apoptose/fisiologia , Aziridinas/toxicidade , Linhagem Celular Tumoral , Colina/antagonistas & inibidores , Colina/metabolismo , Colina/toxicidade , Colinérgicos/farmacologia , Estradiol/metabolismo , Hemicolínio 3/farmacologia , Hibridomas , MAP Quinase Quinase 1/antagonistas & inibidores , MAP Quinase Quinase 1/metabolismo , Camundongos , Bloqueadores Neuromusculares/antagonistas & inibidores , Bloqueadores Neuromusculares/toxicidade , Neurônios/metabolismo , Neurônios/patologia , Fármacos Neuroprotetores/metabolismo , Neurotoxinas/antagonistas & inibidores , Neurotoxinas/toxicidade , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Ratos , Receptores de Estrogênio/antagonistas & inibidores , Receptores de Estrogênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
12.
Am J Psychiatry ; 166(6): 653-61, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19487401

RESUMO

Traumatic brain injury (TBI) is a common occurrence with multiple possible neuropsychiatric sequelae, including problems with cognition, emotion, and behavior. While many individuals experience significant improvement over the first months following mild TBI, a nontrivial minority will develop persistent, functionally impairing post-TBI symptoms. Depression and cognitive impairment are among the most common such symptoms, and they may respond to a combination of rehabilitative and pharmacologic treatments. This article discusses the clinical approach to treating an individual with depression and cognitive complaints following mild TBI. Recommendations regarding the diagnosis, evaluation, and treatment of these problems are offered.


Assuntos
Lesões Encefálicas/complicações , Transtornos Cognitivos/etiologia , Depressão/etiologia , Antidepressivos Tricíclicos/efeitos adversos , Antidepressivos Tricíclicos/uso terapêutico , Encéfalo/anatomia & histologia , Encéfalo/fisiopatologia , Lesões Encefálicas/fisiopatologia , Estimulantes do Sistema Nervoso Central/uso terapêutico , Colina/antagonistas & inibidores , Citalopram/efeitos adversos , Citalopram/uso terapêutico , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/terapia , Terapia Cognitivo-Comportamental/métodos , Depressão/diagnóstico , Depressão/tratamento farmacológico , Humanos , Metilfenidato/uso terapêutico , Testes Neuropsicológicos , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Sertralina/efeitos adversos , Sertralina/uso terapêutico , Índice de Gravidade de Doença
13.
CNS Spectr ; 13(11): 985-96, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19037177

RESUMO

It is widely accepted that cholinergic activity at muscarinic receptors is required to maintain cognitive functions, including learning and memory. Memory domains are especially impaired in schizophrenia, which may explain difficulties in psychosocial rehabilitation of individuals with this illness. However, little is known about the mechanism of this impairment. To understand our current knowledge, we reviewed the literature since 1990 via a PubMed search for the terms "muscarinic", "schizophrenia", "cognition", "memory", "learning", and "agonist" in combination. We found 89 basic science/laboratory studies, case reports/series, case-control studies, cross-sectional studies, standardized controlled animal trials, standardized controlled human trials, and reviews. Although further research is required to fully understand the neuropharmacology of the cholinergic system in cognitive function in schizophrenia, we have examined the data currently available. In general, these data suggest that agonist activity at acetylcholine muscarinic type 1 (M1) receptors would enhance memory and learning in schizophrenia. We present an overview of likely side effects of muscarinic agonists. We outline the anticholinergic activity of several available antipsychotics and review the available M1 muscarinic agonists.


Assuntos
Transtornos Cognitivos/tratamento farmacológico , Transtornos Cognitivos/etiologia , Agonistas Muscarínicos/uso terapêutico , Esquizofrenia/complicações , Animais , Antipsicóticos/efeitos adversos , Colina/antagonistas & inibidores , Transtornos Cognitivos/diagnóstico , Modelos Animais de Doenças , Humanos , Testes Neuropsicológicos
14.
Mol Pharmacol ; 73(3): 801-12, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17971421

RESUMO

Excess formation of nitric oxide and superoxide by-products (peroxynitrite, reactive oxygen, and reactive nitrogen species) attenuates cholinergic transmission potentially having a role in Alzheimer disease pathogenesis. In this study, we investigated mechanisms by which acute exposure to peroxynitrite impairs function of the sodium-dependent hemicholinium-3 (HC-3)-sensitive choline transporter (CHT) that provides substrate for acetylcholine synthesis. The peroxynitrite generator 3-morpholinosydnonimine (SIN-1) acutely inhibited choline uptake in cells stably expressing FLAG-tagged rat CHT in a dose- and time-dependent manner, with an IC(50) = 0.9 +/- 0.14 mM and t((1/2)) = 4 min. SIN-1 significantly reduced V(max) of choline uptake without altering the K(m). This correlated with a SIN-1-induced decrease in cell surface CHT protein, observed as lowered levels of HC-3 binding and biotinylated CHT at the plasma membrane. It is noteworthy that short-term exposure of cells to SIN-1 accelerated the rate of internalization of CHT from the plasma membrane, but it did not alter return of CHT back to the cell surface. SIN-1 did not disrupt cell membrane integrity or cause cell death. Thus, the inhibitory effect of SIN-1 on choline uptake activity and HC-3 binding was related to enhanced internalization of CHT proteins from the plasma membrane to subcellular organelles.


Assuntos
Proteínas de Membrana Transportadoras/metabolismo , Ácido Peroxinitroso/metabolismo , Sódio/metabolismo , Animais , Biotinilação , Técnicas de Cultura de Células , Linhagem Celular , Linhagem Celular Tumoral , Membrana Celular/química , Membrana Celular/metabolismo , Colina/antagonistas & inibidores , Colina/metabolismo , Colinérgicos/metabolismo , Colinérgicos/farmacologia , Meios de Cultura , Interpretação Estatística de Dados , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Hemicolínio 3/metabolismo , Hemicolínio 3/farmacologia , Humanos , Concentração Inibidora 50 , Rim/citologia , Cinética , L-Lactato Desidrogenase/análise , Luminescência , Potenciais da Membrana/efeitos dos fármacos , Proteínas de Membrana Transportadoras/genética , Molsidomina/análogos & derivados , Molsidomina/farmacologia , Neuroblastoma/patologia , Nitrogênio/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ácido Peroxinitroso/biossíntese , Transporte Proteico , Ratos , Frações Subcelulares/metabolismo , Fatores de Tempo , Transfecção , Tirosina/metabolismo
15.
Bioorg Med Chem ; 15(22): 7042-7, 2007 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-17827016

RESUMO

Both N,N'-(2,3-dihydroxybenzyl)-N,N,N',N'-tetramethyl-1,6-hexanediamine dibromide (DTH, 6) and N,N'-(2,3-dihydroxybenzyl)-N,N,N',N'-tetramethyl-1,10-decanediamine dibromide (DTD, 7), which are symmetrical bis-catechol substituted hexamethonium and decamethonium analogues, respectively, were found to inhibit high-affinity choline transport in mouse brain synaptosomes. Inhibitory properties were evaluated using an extraordinarily sensitive capillary electrophoresis method employing electrochemical detection at an enzyme-modified microelectrode. Dose-response curves were generated for each inhibitor and IC(50) values were determined to be 76 microM for 6 and 21 microM for 7. Lineweaver-Burk analysis revealed that both molecules inhibit high-affinity choline uptake by a mixed inhibition mechanism. The K(I) values for 6 and 7 were determined to be 73+/-1 and 31+/-2 microM, respectively. The inhibition properties were further compared to a series of mono-catechol analogues, 3-[(trimethylammonio)methyl]catechol (1), N,N-dimethylepinephrine (4) and 6-hydroxy-N,N-dimethylepinephrine (5), as well as the well-characterized hemicholinium inhibitors, hemicholinium-15 (HC-15, 8) and hemicholinum-3 (HC-3, 9).


Assuntos
Catecóis/farmacologia , Colina/antagonistas & inibidores , Colinérgicos/farmacologia , Animais , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/fisiologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Colina/metabolismo , Colina/farmacocinética , Relação Dose-Resposta a Droga , Eletroquímica , Eletroforese Capilar , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microeletrodos , Estrutura Molecular , Oxirredução , Sensibilidade e Especificidade , Estereoisomerismo , Sinaptossomos/efeitos dos fármacos , Sinaptossomos/metabolismo
16.
J Neurochem ; 94(5): 1427-37, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16000150

RESUMO

In this study, we examined the molecular and functional characterization of choline uptake into cultured rat cortical astrocytes. Choline uptake into astrocytes showed little dependence on extracellular Na+. Na+-independent choline uptake was saturable and mediated by a single transport system, with an apparent Michaelis-Menten constant (Km) of 35.7 +/- 4.1 microm and a maximal velocity (Vmax) of 49.1 +/- 2.0 pmol/mg protein/min. Choline uptake was significantly decreased by acidification of the extracellular medium and by membrane depolarization. Na+-independent choline uptake was inhibited by unlabeled choline, acetylcholine and the choline analogue hemicholinium-3. The prototypical organic cation tetrahexylammonium (TEA), and other n-tetraalkylammonium compounds such as tetrabutylammonium (TBA) and tetrahexylammonium (THA), inhibited Na+-independent choline uptake, and their inhibitory potencies were in the order THA > TBA > TEA. Various organic cations, such as 1-methyl-4-tetrahydropyridinium (MPP+), clonidine, quinine, quinidine, guanidine, N-methylnicotinamide, cimetidine, desipramine, diphenhydramine and verapamil, also interacted with the Na+-independent choline transport system. Corticosterone and 17beta-estradiol, known inhibitors of organic cation transporter 3 (OCT3), did not cause any significant inhibition. However, decynium22, which inhibits OCTs, markedly inhibited Na+-independent choline uptake. RT-PCR demonstrated that astrocytes expressed low levels of OCT1, OCT2 and OCT3 mRNA, but the functional characteristics of choline uptake are very different from the known properties of these OCTs. The high-affinity Na+-dependent choline transporter, CHT1, is not expressed in astrocytes as evidenced by RT-PCR. Furthermore, mRNA for choline transporter-like protein 1 (CTL1), and its splice variants CTL1a and CTL1b, was expressed in rat astrocytes, and the inhibition of CTL1 expression by RNA interference completely inhibited Na+-independent choline uptake. We conclude that rat astrocytes express an intermediate-affinity Na+-independent choline transport system. This system seems to occur through a CTL1 and is responsible for the uptake of choline and organic cations in these cells.


Assuntos
Astrócitos/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Sódio/fisiologia , Animais , Cátions/farmacologia , Células Cultivadas , Córtex Cerebral/citologia , Colina/antagonistas & inibidores , Colina/farmacocinética , DNA Recombinante , Líquido Extracelular/metabolismo , Variação Genética , Concentração de Íons de Hidrogênio , Cinética , Potenciais da Membrana/fisiologia , Proteínas de Membrana Transportadoras/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/farmacologia , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo
17.
Anal Biochem ; 339(2): 216-22, 2005 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15797561

RESUMO

A nonradiochemical in vitro assay using capillary electrophoresis with electrochemical detection at an enzyme-modified microelectrode has been developed to evaluate the inhibition of high-affinity choline transport in synaptosomes. Quantitative analysis of high-affinity choline transporter rates as a function of inhibitor and substrate concentrations allowed determination of the mode of inhibition for the quaternary ammonium-catechol-based inhibitors 3-[(trimethylammonio)methyl]catechol, N,N-dimethylepinephrine, and 6-hydroxy-N,N-dimethylepinephrine. The results are compared to the well-characterized inhibitor of choline transport, hemicholinium-3.


Assuntos
Colina/antagonistas & inibidores , Colina/farmacocinética , Eletroforese Capilar/métodos , Sinaptossomos/metabolismo , Acetilcolinesterase/metabolismo , Oxirredutases do Álcool/metabolismo , Animais , Colinérgicos/farmacologia , Eletroquímica , Enzimas Imobilizadas , Epinefrina/análogos & derivados , Epinefrina/metabolismo , Peróxido de Hidrogênio/análise , Microeletrodos , Sensibilidade e Especificidade
18.
Brain Res ; 1033(1): 34-40, 2005 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-15680337

RESUMO

Glycosaminoglycans (GAGs) play a pivotal role in the pathogenesis of Alzheimer's disease (AD). Although, as we have shown earlier, a low molecular weight GAG, C3, protects against ethylcholine aziridinium (AF64A)-induced cholinergic damage, and against A(beta)-induced tau-2-immunoreactivity (IR), the mechanism of the neuroprotective effect of GAGs is not yet known. Several clues exist. Previous studies in rats revealed that continuous NGF infusion (icv) after AF64A injection increases septal ChAT and AChE activities. Moreover, C3 increases axonal outgrowth in the rat hippocampus, raising the possibility of a NGF-receptor mediated neuroprotection. Furthermore, it has been reported that NGF expression is increased in the septum following AF64A administration. To study the question regarding the mechanism of neuroprotective action of GAGs, AF64A, a selective cholinotoxin, was administered stereotaxically, bilaterally, into the lateral ventricles of Fischer albino male rats (1 nmol/2 microl/side). In order to establish the effect of C3 on the expression of the NGF receptor-IR elements, C3 was administered orally (25 mg/kg, once a day), by gavage, 7 days before, and 7 days after the AF64A injection. NGF receptor immunohistochemistry revealed that AF64A induced the appearance of NGF-receptor-IR axonal varicosities in the rat medial septum. These varicose fibers were attenuated by 14 days' administration of C3. The possible explanation of our data may be that C3 increases NGF synthesis in the lateral septum. The increased level of NGF could suppress the increased, AF64A-induced NGF receptor expression in the medial septal nucleus. These results further accentuate our earlier observations that C3 may have potential as a therapeutic agent in AD and other neurodegenerative disorders.


Assuntos
Axônios/efeitos dos fármacos , Aziridinas/farmacologia , Colina/análogos & derivados , Colina/farmacologia , Complemento C3/farmacologia , Glicosaminoglicanos/farmacologia , Bloqueadores Neuromusculares/farmacologia , Receptor de Fator de Crescimento Neural/metabolismo , Septo do Cérebro/citologia , Animais , Axônios/metabolismo , Aziridinas/antagonistas & inibidores , Colina/antagonistas & inibidores , Colina O-Acetiltransferase/metabolismo , Interações Medicamentosas , Regulação da Expressão Gênica/efeitos dos fármacos , Imuno-Histoquímica/métodos , Masculino , Inibição Neural/efeitos dos fármacos , Bloqueadores Neuromusculares/antagonistas & inibidores , Ratos , Ratos Endogâmicos F344 , Receptores de Fator de Crescimento Neural/metabolismo , Septo do Cérebro/efeitos dos fármacos
19.
Toxicon ; 44(5): 521-8, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15450927

RESUMO

The aim of this work was to study the mechanisms involved in intestinal permeability of gonyautoxins. For this purpose, the influence on transmucosal resistance of gonyautoxins and their permeability was investigated in excised human jejunal segments. To evaluate these events, the isolated mucosa was mounted in Ussing chambers for electrophysiological characterization. The organic gonyautoxin cations were applied to the mucosal side and samples collected on the serosal side. The permeability of gonyautoxins measured at 37 degrees C was 4.3-fold greater than at 4 degrees C, indicative of high cation selective transcellular permeability. In order to characterize the permeability of gonyautoxins, the effects of choline, ouabain, phlorizin and fluorescein were studied. The inhibition by these compounds was expressed as percent inhibition of the maximal flux of gonyautoxins at 120 min. Replacement of sodium ion by choline, showed the highest inhibition (85.5% from control). Ouabain, fluorescein and phlorizin inhibit the gonyautoxins flux by 53.9, 41.0 and 9.64%, respectively. The inhibition of gonyautoxins' permeability produced by ouabain and phlorizin go in parallel with an increase in the transmucosal electrical resistance (TER). This study shows that permeability of gonyautoxin cations occurred predominantly by the transcellular pathway (76%) when toxins were applied in the mucosal-serosal direction. The paracellular pathway of gonyautoxins was 24% of total permeability when compared with [3H] mannitol permeability. These findings suggests that permeability of gonyautoxins depends on temperature and processes involving sodium ion. Replacing sodium ions by choline ions showed a marked effect on TER.


Assuntos
Jejuno/metabolismo , Saxitoxina/análogos & derivados , Saxitoxina/farmacocinética , Transporte Biológico Ativo/fisiologia , Cátions/metabolismo , Colina/antagonistas & inibidores , Colina/farmacologia , Eletrofisiologia , Humanos , Mucosa Intestinal/metabolismo , Jejuno/efeitos dos fármacos , Ouabaína/antagonistas & inibidores , Ouabaína/farmacologia , Permeabilidade/efeitos dos fármacos , Florizina/antagonistas & inibidores , Florizina/farmacologia , Membrana Serosa/metabolismo , Sódio/farmacologia , Temperatura , Fatores de Tempo
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