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1.
Artigo em Inglês | MEDLINE | ID: mdl-29868238

RESUMO

BACKGROUND: Intimate partner violence (IPV) during pregnancy is prevalent across the world, but more so in low- and middle-income countries. It is associated with various adverse outcomes for mothers and infants. This study sought to determine the prevalence and predictors of IPV among pregnant women attending one midwife and obstetrics unit (MOU) in the Western Cape, South Africa. METHODS: A convenience sample of 150 pregnant women was recruited to participate in the study. Data were collected using several self-report measures concerning the history of childhood trauma, exposure to community violence, depression and alcohol use. Multivariable logistic models were developed, the first model was based on whether any IPV occurred, the remaining models investigated for physical-, sexual- and emotional abuse. RESULTS: Lifetime and 12-month prevalence rates for any IPV were 44%. The 12-month IPV rates were 32% for emotional and controlling behaviours, 29% physical and 20% sexual abuse. The adjusted model predicting physical IPV found women who were at risk for depression were more likely to experience physical IPV [odds ratios (ORs) 4.42, 95% confidence intervals (CIs) 1.88-10.41], and the model predicting sexual IPV found that women who reported experiencing community violence were more likely to report 12-month sexual IPV (OR 3.85, CI 1.14-13.08). CONCLUSION: This is the first study, which illustrates high prevalence rates of IPV among pregnant woman at Mitchells Plain MOU. A significant association was found between 12-month IPV and unintended pregnancy. Further prospective studies in different centres are needed to address generalisability and the effect of IPV on maternal and child outcomes.

2.
Transl Psychiatry ; 6: e786, 2016 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-27093068

RESUMO

Species-conserved (intermediate) phenotypes that can be quantified and compared across species offer important advantages for translational research and drug discovery. Here, we investigate the utility of network science methods to assess the pharmacological alterations of the large-scale architecture of brain networks in rats and humans. In a double-blind, placebo-controlled, cross-over study in humans and a placebo-controlled two-group study in rats, we demonstrate that the application of ketamine leads to a topological reconfiguration of large-scale brain networks towards less-integrated and more-segregated information processing in both the species. As these alterations are opposed to those commonly observed in patients suffering from depression, they might indicate systems-level correlates of the antidepressant effect of ketamine.


Assuntos
Encéfalo/efeitos dos fármacos , Antagonistas de Aminoácidos Excitatórios/farmacologia , Ketamina/farmacologia , Adulto , Animais , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Masculino , Ratos , Ratos Sprague-Dawley
3.
Mol Psychiatry ; 20(11): 1420-7, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25560759

RESUMO

Antidepressant drugs are commonly prescribed treatments for anxiety disorders, and there is growing interest in understanding how these drugs impact fear extinction because extinction learning is pivotal to successful exposure-based therapy (EBT). A key objective within this domain is understanding how antidepressants alter the activation of specific elements of the limbic-based network that governs such fear processing. Chronic treatment with the antidepressant tianeptine has been shown to reduce the acquisition of extinction learning in rats, yet the drug's acute influence on activation in prefrontal and amygdalar regions, and on extinction learning are not well understood. To assess its influence on cellular activation, rats were injected with tianeptine and Fos immunoreactivity was measured in these regions. Acute tianeptine treatment selectively altered Fos expression within subdivisions of the central nucleus of the amygdala (CEA) in a bidirectional manner that varied in relation to ongoing activation within the capsular subdivision and its prefrontal and intra-amygdalar inputs. This pattern of results suggests that the drug can conditionally modulate the activation of CEA subdivisions, which contain microcircuits strongly implicated in fear processing. The effect of acute tianeptine was also examined with respect to the acquisition, consolidation and expression of fear extinction in rats. Acute tianeptine attenuated extinction learning as well as the recall of extinction memory, which underscores that acute dosing with the drug could alter learning during EBT. Together these findings provide a new perspective for understanding the mechanism supporting tianeptine's clinical efficacy, as well as its potential influence on CEA-based learning mechanisms.


Assuntos
Antidepressivos Tricíclicos/farmacologia , Núcleo Central da Amígdala/citologia , Extinção Psicológica/efeitos dos fármacos , Medo/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Tiazepinas/farmacologia , Estimulação Acústica/efeitos adversos , Análise de Variância , Animais , Núcleo Central da Amígdala/efeitos dos fármacos , Condicionamento Psicológico/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
4.
Br J Pharmacol ; 171(8): 2206-29, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24720259

RESUMO

The brain is at the very limit of its energy supply and has evolved specific means of adapting function to energy supply, of which mitochondria form a crucial link. Neurotrophic and inflammatory processes may not only have opposite effects on neuroplasticity, but also involve opposite effects on mitochondrial oxidative phosphorylation and glycolytic processes, respectively, modulated by stress and glucocorticoids, which also have marked effects on mood. Neurodegenerative processes show marked disorders in oxidative metabolism in key brain areas, sometimes decades before symptoms appear (Parkinson's and Alzheimer's diseases). We argue that brain-derived neurotrophic factor couples activity to changes in respiratory efficiency and these effects may be opposed by inflammatory cytokines, a key factor in neurodegenerative processes.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/fisiologia , Transtornos Mentais/metabolismo , Transtornos Mentais/fisiopatologia , Mitocôndrias/fisiologia , Doenças Neurodegenerativas/metabolismo , Envelhecimento/metabolismo , Envelhecimento/fisiologia , Animais , Apoptose/fisiologia , Encéfalo/metabolismo , Cálcio/metabolismo , Cognição/fisiologia , Ingestão de Energia/fisiologia , Exercício Físico/fisiologia , Glucocorticoides/fisiologia , Humanos , Mitocôndrias/metabolismo , Dinâmica Mitocondrial/fisiologia , Renovação Mitocondrial/fisiologia , Modelos Neurológicos , Doenças Neurodegenerativas/fisiopatologia , Neurogênese/fisiologia , Plasticidade Neuronal/fisiologia , Fármacos Neuroprotetores/metabolismo
5.
Br J Pharmacol ; 171(8): 1795-7, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24684388

RESUMO

While the mitochondrion has long fascinated biologists and the sheer diversity of druggable targets has made it attractive for potential drug development, there has been little success translatable to the clinic. Given the diversity of inborn errors of metabolism and mitochondrial diseases, mitochondrially mediated oxidative stress (myopathies, reperfusion injury, Parkinson's disease, ageing) and the consequences of disturbed energetics (circulatory shock, diabetes, cancer), the potential for meaningful gain with novel drugs targeting mitochondrial mechanisms is huge both in terms of patient quality of life and health care costs. In this themed issue of the British Journal of Pharmacology, we highlight the key directions of the contemporary advances in the field of mitochondrial biology, emerging drug targets and new molecules which are close to clinical application. Authors' contributions are diverse both in terms of species and organs in which the mitochondrially related studies are performed, and from the perspectives of mechanisms under study. Defined roles of mitochondria in disease are updated and previously unknown contributions to disease are described in terms of the interface between basic science and pathological relevance.


Assuntos
Metabolismo Energético/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Doenças Mitocondriais/tratamento farmacológico , Doenças Mitocondriais/patologia , Terapia de Alvo Molecular/métodos , Desenho de Fármacos , Humanos , Mitocôndrias/patologia
6.
Neuroscience ; 228: 243-58, 2013 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-23098800

RESUMO

Interactions between the hippocampus and the prefrontal cortex (PFC) are of major interest in the neurobiology of psychiatric and neurodegenerative disorders and are central to many experimental rodent models. Non-invasive imaging techniques offer a translatable approach to probing this system if homologous features can be identified across species. The objective of the present study was to systematically characterize the rat brain connectivity signature derived from low-frequency resting blood oxygenation level-dependent (BOLD) oscillations associated with and within the hippocampal-prefrontal network, using an array of small seed locations within the relatively large anatomical structures comprising this system. A heterogeneous structure of functional connectivity, both between and within the hippocampal-prefrontal brain structures, was observed. In the hippocampal formation, the posterior (subiculum) region correlated more strongly than the anterior dorsal hippocampus with the PFC. A homologous relationship was found in the human hippocampus, with differential functional connectivity between hippocampal locations proximal to the fornix body relative to locations more distal being localized to the medial prefrontal regions in both species. The orbitofrontal cortex correlated more strongly with sensory cortices and a heterogeneous dependence of functional coupling on seed location was observed along the midline cingulate and retrosplenial cortices. These findings are all convergent with known anatomical connectivity, with stronger BOLD correlations corresponding to known monosynaptic connections. These functional connectivity relationships may provide a useful translatable probe of the hippocampal-prefrontal system for the further study of rodent models of disease and potential treatments, and inform electrode placement in electrophysiology to yield more precise descriptors of the circuits at risk in psychiatric disease.


Assuntos
Hipocampo/metabolismo , Rede Nervosa/metabolismo , Oxigênio/metabolismo , Córtex Pré-Frontal/metabolismo , Adulto , Animais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vias Neurais/metabolismo , Desempenho Psicomotor/fisiologia , Ratos , Ratos Sprague-Dawley , Adulto Jovem
7.
Mol Psychiatry ; 18(4): 471-84, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22733125

RESUMO

The plasticity of excitatory synapses is an essential brain process involved in cognitive functions, and dysfunctions of such adaptations have been linked to psychiatric disorders such as depression. Although the intracellular cascades that are altered in models of depression and stress-related disorders have been under considerable scrutiny, the molecular interplay between antidepressants and glutamatergic signaling remains elusive. Using a combination of electrophysiological and single nanoparticle tracking approaches, we here report that the cognitive enhancer and antidepressant tianeptine (S 1574, [3-chloro-6-methyl-5,5-dioxo-6,11-dihydro-(c,f)-dibenzo-(1,2-thiazepine)-11-yl) amino]-7 heptanoic acid, sodium salt) favors synaptic plasticity in hippocampal neurons both under basal conditions and after acute stress. Strikingly, tianeptine rapidly reduces the surface diffusion of AMPA receptor (AMPAR) through a Ca(2+)/calmodulin-dependent protein kinase II (CaMKII)-dependent mechanism that enhances the binding of AMPAR auxiliary subunit stargazin with PSD-95. This prevents corticosterone-induced AMPAR surface dispersal and restores long-term potentiation of acutely stressed mice. Collectively, these data provide the first evidence that a therapeutically used drug targets the surface diffusion of AMPAR through a CaMKII-stargazin-PSD-95 pathway, to promote long-term synaptic plasticity.


Assuntos
Antidepressivos Tricíclicos/farmacologia , Plasticidade Neuronal/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Receptores de AMPA/metabolismo , Sinapses/efeitos dos fármacos , Tiazepinas/farmacologia , Animais , Anti-Inflamatórios/farmacologia , Benzilaminas/farmacologia , Canais de Cálcio/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/antagonistas & inibidores , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Corticosterona/farmacologia , Proteína 4 Homóloga a Disks-Large , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Guanilato Quinases/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Plasticidade Neuronal/fisiologia , Inibidores de Proteínas Quinases/farmacologia , Transporte Proteico/fisiologia , Transdução de Sinais/efeitos dos fármacos , Sulfonamidas/farmacologia , Sinapses/metabolismo
8.
Mol Psychiatry ; 17(2): 173-84, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21242991

RESUMO

Cognitive dysfunctions are common in major depressive disorder, but have been difficult to recapitulate in animal models. This study shows that Flinders sensitive line (FSL) rats, a genetic rat model of depression, display a pronounced impairment of emotional memory function in the passive avoidance (PA) task, accompanied by reduced transcription of Arc in prefrontal cortex and hippocampus. At the cellular level, FSL rats have selective reductions in levels of NMDA receptor subunits, serotonin 5-HT(1A) receptors and MEK activity. Treatment with chronic escitalopram, but not with an antidepressant regimen of nortriptyline, restored memory performance and increased Arc transcription in FSL rats. Multiple pharmacological manipulations demonstrated that procognitive effects could also be achieved by either disinhibition of 5-HT(1A)R/MEK/Arc or stimulation of 5-HT4R/MEK/Arc signaling cascades. Taken together, studies of FSL rats in the PA task revealed reversible deficits in emotional memory processing, providing a potential model with predictive and construct validity for assessments of procognitive actions of antidepressant drug therapies.


Assuntos
Complexo Relacionado com a AIDS/metabolismo , Depressão/complicações , Emoções/fisiologia , Sistema de Sinalização das MAP Quinases/fisiologia , Transtornos da Memória/etiologia , Receptores de Serotonina/metabolismo , Análise de Variância , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Aprendizagem da Esquiva/fisiologia , Benzopiranos/farmacologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Citalopram/uso terapêutico , Depressão/tratamento farmacológico , Depressão/genética , Modelos Animais de Doenças , Maleato de Dizocilpina/farmacologia , Inibidores Enzimáticos/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Comportamento Exploratório/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Hipocampo/metabolismo , Imunoprecipitação , Sistema de Sinalização das MAP Quinases/genética , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/patologia , Córtex Pré-Frontal/metabolismo , Ratos , Ratos Mutantes , Receptores de N-Metil-D-Aspartato/metabolismo , Serotonina/metabolismo , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Natação/psicologia
9.
Cell Death Differ ; 16(4): 624-37, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19136940

RESUMO

Positive alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor modulators include benzamide compounds that allosterically modulate AMPA glutamate receptors. These small molecules that cross the blood-brain barrier have been shown to act as a neuroprotectant by increasing the levels of endogenous brain-derived neurotrophic factor (BDNF). Positive AMPA receptor modulators have also been shown to increase the levels of growth-associated protein-43 (GAP-43). GAP-43 plays a major role in many aspects of neuronal function in vertebrates. The goal of this study was to determine whether GAP-43 was important in mediating the actions of positive AMPA receptor modulator (S18986) and BDNF. Using cortical cultures from GAP-43 knockout and control mice, we show that (1) GAP-43 is upregulated in response to S18986 and BDNF in control cultures; (2) this upregulation of GAP-43 is essential for mediating the neuroprotective effects of S18986 and BDNF; (3) administration of S18986 and BDNF leads to an increase in the expression of the glutamate transporters GLT-1 and GLAST that are key to limiting excitotoxic cell death and this increase in GLT-1 and GLAST expression is completely blocked in the absence of GAP-43. Taken together this study concludes that GAP-43 is an important mediator of the neurotrophic effects of S18986 and BDNF on neuronal survival and plasticity, and is essential for the success of positive AMPA receptor modulator-BDNF-based neurotrophin therapy.


Assuntos
Benzotiadiazinas/farmacologia , Fator Neurotrófico Derivado do Encéfalo/farmacologia , Córtex Cerebral/efeitos dos fármacos , Proteína GAP-43/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Receptores de AMPA/agonistas , Animais , Western Blotting , Morte Celular/efeitos dos fármacos , Células Cultivadas , Córtex Cerebral/citologia , Proteína GAP-43/genética , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Técnicas In Vitro , Camundongos , Camundongos Knockout , Reação em Cadeia da Polimerase , Espécies Reativas de Oxigênio/metabolismo
10.
Br J Pharmacol ; 154(3): 496-501, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18500377

RESUMO

This article, by the United Kingdom's last Olympic Marathon Medal winner, Charlie Spedding, and his brother, the pharmacologist, Michael Spedding, covers the difficulties posed by the availability of powerful drugs to ameliorate athletic performance, from an athlete's perspective, particularly in view of the fact that performances are becoming highly optimised with less margin for further physiological improvement. The authors have had long athletic careers and argue that doping not only devalues performance but sport, and exercise, as a whole. Furthermore, the neurotrophic and metabolic changes involved in exercise and training, which can be modified by drugs, are central to health and reflect a part of the epidemic in obesity.


Assuntos
Desempenho Atlético , Dopagem Esportivo , Esportes , Eritropoetina/metabolismo , Exercício Físico , Hematócrito , Humanos
11.
Eur J Neurosci ; 20(5): 1189-96, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15341590

RESUMO

Brain-derived neurotrophic factor (BDNF) governs both the selective survival of neurons during development and the experience-based regulation of synaptic strength throughout life. BDNF produced a concentration-dependent increase in the respiratory control index (RCI, a measure of the efficiency of respiratory coupling, ATP synthesis and organelle integrity) of rat brain mitochondria. This effect was mediated via a MAP kinase pathway and highly specific for oxidation of glutamate plus malate (complex I) by brain mitochondria. The oxidation by brain mitochondria of the complex II substrate succinate was unaffected by BDNF. The failure of BDNF to modify respiratory activity associated with mitochondrial preparations isolated from rat liver indicates that the actions of the neurotrophin are tissue specific. BDNF also increased the RCI values associated with Ca2+ -induced respiration to a similar extent. This is the first demonstration that BDNF, in addition to modifying neuronal plasticity, can modify brain metabolism and the efficiency of oxygen utilization. The finding that neurotrophins can alter mitochondrial oxidative efficiency has important implications for neurodegenerative and psychiatric diseases.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/fisiologia , Encéfalo/fisiologia , Complexo II de Transporte de Elétrons/biossíntese , Complexo I de Transporte de Elétrons/biossíntese , Mitocôndrias/fisiologia , Consumo de Oxigênio/fisiologia , Regulação para Cima/fisiologia , Animais , Encéfalo/enzimologia , Encéfalo/ultraestrutura , Complexo I de Transporte de Elétrons/metabolismo , Complexo II de Transporte de Elétrons/metabolismo , Feminino , Mitocôndrias/enzimologia , Mitocôndrias/ultraestrutura , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Ratos , Ratos Wistar
12.
Neuropharmacology ; 44(6): 801-9, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12681378

RESUMO

Tianeptine is an antidepressant with proven clinical efficacy and effects on hippocampal plasticity. Hypoxia increased lactate dehydrogenase (LDH) release from cortical neuronal cultures, and tianeptine (1, 10 and 100 microM) inhibited LDH release as efficiently as the N-methyl-D-aspartate (NMDA) antagonist, MK-801. However, tianeptine did not block apoptosis in cultured cortical neurones caused by NMDA, but reduced apoptosis when interleukin-1beta (IL-1beta) was included with NMDA. In 5-day old mice, intracerebral injection of ibotenate induced reproducible lesions in cortex and white matter. Lesion size was markedly reduced by co-administration of MK-801 (1 mg/kg i.p.) but neither by tianeptine or its enantiomers administered acutely (1, 3 or 10 mg/kg i.p.) nor by tianeptine administered chronically (10 mg/kg i.p. for 5 days). Chronic administration of IL-1beta (10 ng/kg i.p. for 5 days) prior to ibotenate injection exacerbated lesion size in cortex and white matter, and this exacerbation was prevented by chronic pre-treatment with tianeptine (10 mg/kg i.p.) or by acute administration of tianeptine (10 mg/kg i.p.) concomitantly with ibotenate. Thus tianeptine has neuroprotective effects against hypoxia in tissue culture and against the deleterious effects of cytokines in cortex and white matter, but not against NMDA receptor-mediated excitotoxicity.


Assuntos
Antidepressivos Tricíclicos/farmacologia , Citocinas/metabolismo , Fármacos Neuroprotetores/farmacologia , Tiazepinas/farmacologia , Animais , Animais Recém-Nascidos , Antidepressivos Tricíclicos/química , Encéfalo/metabolismo , Encéfalo/patologia , Hipóxia Celular , Células Cultivadas , Maleato de Dizocilpina/farmacologia , Relação Dose-Resposta a Droga , Agonistas de Aminoácidos Excitatórios , Hipóxia/metabolismo , Hipóxia/patologia , Ácido Ibotênico , Interleucina-1/farmacologia , L-Lactato Desidrogenase/metabolismo , Camundongos , Plasticidade Neuronal/efeitos dos fármacos , Plasticidade Neuronal/fisiologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fármacos Neuroprotetores/química , Ratos , Ratos Sprague-Dawley , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Estereoisomerismo , Tiazepinas/química
13.
Pharmacol Rev ; 54(2): 231-2, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12037139

RESUMO

A receptor is defined by the International Union of Pharmacology Committee on Receptor Nomenclature and Drug Classification (NC-IUPHAR) as a protein, or a complex of proteins, which recognizes physiologically relevant ligands that can regulate the protein to mediate cellular events (Ruffolo et al., 2000). This definition does not include associated proteins, which are not required for agonist recognition and/or receptor assembly. Thus, G proteins are not included in the nomenclature of G protein-coupled receptors (GPCRs). Similarly, proteins which modify receptor disposition, such as proteins with a PDZ domain (Sheng and Sala, 2001), and which associate with the cytosolic portion of the receptor are not included. The question arises, however, as to the way to name multimeric receptors where subunits influence receptor assembly and agonist recognition. The essential issue is whether to name the individual proteins or the association of proteins? NC-IUPHAR recommends that, where possible, the functional receptor complex be given a different name from that of the subunits.


Assuntos
Receptores de Superfície Celular/classificação , Terminologia como Assunto , Agências Internacionais , Receptores da Calcitonina/classificação , Receptores de GABA-B/classificação
14.
Eur J Pharmacol ; 424(3): 189-94, 2001 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-11672561

RESUMO

Antioxidant 8-alkylamino-1,4-benzoxazines, (R,S)-(3-tert-butyl-8-phenylethylamino-3,4-dihydro-2H-1,4-benzoxazin-5-yl) (phenyl) methanone (S 24429) and (R,S)-(3-cyclopentyl-8-benzylamino-3,4-dihydro-2H-1,4-benzoxazin-5-yl) (phenyl) methanone (S 24718), were prepared according to a two-step one-pot electrochemical procedure. These compounds had been selected from a previous study of structure/activity. Both compounds (1-100 microM) prevented the fall in ATP levels caused by 24 h of hypoxia in astrocytes. Both compounds (1 and 10 mg/kg i.p.) were powerful neuroprotective agents in protecting against the lesions induced by 15 microg S-bromo-willardiine injected into the cortex or white matter of 5-day old mice pups. In contrast, exifone, an antioxidant compound, was inactive at these doses. S 24429 and S 24718 appear to be novel neuroprotective agents, which are effective in a model of brain damage mimicking the lesions underlying cerebral palsy.


Assuntos
Alanina/análogos & derivados , Antioxidantes/farmacologia , Fármacos Neuroprotetores/farmacologia , Oxazinas/farmacologia , Trifosfato de Adenosina/metabolismo , Alanina/administração & dosagem , Animais , Animais Recém-Nascidos , Astrócitos/citologia , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Benzofenonas/farmacologia , Benzoxazinas , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Relação Dose-Resposta a Droga , Camundongos , Oxigênio/farmacologia , Ratos
15.
Neuropharmacology ; 41(2): 272-81, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11489464

RESUMO

Tianeptine, an atypical antidepressant that exhibits clinical efficacy in measures of depression and anxiety, has been reported to enhance learning and memory in rats under certain conditions, an effect not observed with other tricyclic antidepressants. The present study explores further the possibility that tianeptine or its enantiomers (S 16190 and S 16191) can enhance either learning or retention in animals in which the hippocampus has been made partially dysfunctional. The effects of tianeptine and its enantiomers were tested using an open field watermaze test, in rats with partial lesions of the medial septum/diagonal band of Broca (MSDB). When given to normal rats, tianeptine (10 mg/kg, i.p.) did not significantly affect learning as compared to animals injected with saline. We therefore created, in other animals, partial ibotenic acid lesions of MSDB and showed histochemically that these lesions reduced but did not abolish the density of acetylcholinesterase staining in the hippocampus. They impaired both the acquisition of place-navigation and the long-term retention of spatial information over 7 days. Against the baseline of impaired performance in animals with these lesions, neither tianeptine (10 mg/kg) nor its enantiomers (5 mg/kg) affected the rate of acquisition of place navigation. However, tianeptine did enhance the retention of spatial memory over 7 days. These results are discussed in relation to different effects that tianeptine may have on learning including its ability to block stress-induced dendritic re-modelling of the hippocampus.


Assuntos
Antidepressivos Tricíclicos/farmacologia , Aprendizagem em Labirinto/efeitos dos fármacos , Memória/efeitos dos fármacos , Núcleos Septais/fisiologia , Tiazepinas/farmacologia , Animais , Hipocampo/efeitos dos fármacos , Hipocampo/fisiologia , Masculino , Aprendizagem em Labirinto/fisiologia , Memória/fisiologia , Ratos , Tempo de Reação/efeitos dos fármacos , Tempo de Reação/fisiologia , Núcleos Septais/efeitos dos fármacos , Estereoisomerismo , Técnicas Estereotáxicas , Natação/fisiologia
16.
Adv Drug Deliv Rev ; 49(1-2): 151-74, 2001 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-11377809

RESUMO

The cessation of blood flow followed by a reperfusion period results in severe damages to cell structures. This induces a complex cascade of events involving, more particularly, a loss of energy, an alteration of ionic homeostasis promoting H(+) and Ca(2+) build up and the generation of free radicals. In this context, mitochondria are highly vulnerable and play a predominant role in the cell signaling leading from life to death. This is why, recently, efforts to find an effective therapy for ischemia-reperfusion injury have focused on mitochondria. This review summarizes the pharmacological strategies which are currently developed and the potential mitochondrial targets which could be involved in the protection of cells.


Assuntos
Antioxidantes/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Inibidores Enzimáticos/administração & dosagem , Canais Iônicos , Mitocôndrias/efeitos dos fármacos , Traumatismo por Reperfusão/tratamento farmacológico , Acetanilidas , Animais , Coenzimas , Humanos , Proteínas de Membrana/efeitos dos fármacos , Proteínas de Membrana/metabolismo , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial , Poro de Transição de Permeabilidade Mitocondrial , Piperazinas/administração & dosagem , Canais de Potássio/efeitos dos fármacos , Canais de Potássio/metabolismo , Ranolazina , Traumatismo por Reperfusão/metabolismo , Trocador de Sódio e Cálcio/efeitos dos fármacos , Trocador de Sódio e Cálcio/metabolismo , Trimetazidina/administração & dosagem , Ubiquinona/administração & dosagem , Ubiquinona/análogos & derivados , Vasodilatadores/administração & dosagem
18.
Neuropharmacology ; 40(3): 334-44, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11166326

RESUMO

S 14506 is chemically related to the inverse agonist at 5-HT(1A) receptors, spiperone, but S 14506 behaves as one of the most potent agonists known at these receptors, both in vitro and in vivo. In hippocampal membranes, the specific binding of [(3)H]-S 14506 (K(d)=0.79+/-0.2 nM; B(max)=400+/-32 fmol/mg protein) to 5-HT(1A) receptors resembled that of an antagonist in that it was increased by GppNHp, whereas GppNHp reduced the binding of the classic agonist [(3)H]-8-OH-DPAT (K(d)=1.5+/-0.5 nM; B(max)=303+/-20 fmol/mg protein). Manganese, magnesium and calcium reduced the binding of [(3)H]-S 14506 to 5-HT(1A) receptors whereas the binding of [(3)H]-8-OH-DPAT was increased. Further, sodium markedly reduced the binding of [(3)H]-8-OH-DPAT, without affecting the binding of [(3)H]-S 14506. [(3)H]-S 14506 also bound with high affinity to h 5-HT(1A) receptors stably expressed in membranes of CHO cells (K(d)=0.13+/-0.05 nM; B(max)=2.99+/-0.60 pmol/mg protein): the B(max) was double that of [(3)H]-8-OH-DPAT. GppNHp strongly decreased [(3)H]-8-OH-DPAT binding but scarcely changed [(3)H]-S 14506 binding; calcium, magnesium and manganese had little effect on [(3)H]-S 14506 binding in CHO cells. Antagonists (WAY 100635, WAY 100135) and inverse agonists (spiperone and metitepine) displaced [(3)H]-S 14506 binding with high affinity and Hill slopes close to unity, whereas agonists (5-HT and 5-CT) displayed low affinity with low Hill slopes: partial agonists (buspirone, ipsapirone) showed intermediate properties. In fusion proteins of h 5-HT(1A) receptors with G(ialpha1) the compound potently increased high-affinity GTPase, with a steeper Hill slope than for 5-HT, which may indicate positive cooperativity. The maximum response for S 14506 in these assays was equivalent to 5-HT, indicating it to be a full agonist.In molecular modelling studies, using a three-site model of the 5-HT(1A) receptor, S 14506 spanned between the 5-HT recognition site and the "arginine switch" (DRY microdomain) postulated to activate the interaction of the receptor with the G protein. Thus it is possible to synthesise ligands at G-protein-coupled receptors which are highly potent agonists, but which are structurally related to inverse agonists and show some features of antagonist/inverse agonist binding.


Assuntos
Benzamidas/farmacologia , Piperazinas/farmacologia , Receptores de Serotonina/metabolismo , Agonistas do Receptor de Serotonina/farmacologia , 8-Hidroxi-2-(di-n-propilamino)tetralina/antagonistas & inibidores , 8-Hidroxi-2-(di-n-propilamino)tetralina/farmacologia , Animais , Ligação Competitiva/efeitos dos fármacos , Células CHO , Membrana Celular/metabolismo , Cricetinae , Antagonistas de Dopamina/farmacologia , GTP Fosfo-Hidrolases/metabolismo , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/genética , Guanilil Imidodifosfato/farmacologia , Hipocampo/química , Hipocampo/metabolismo , Humanos , Substâncias Macromoleculares , Metiotepina/farmacologia , Modelos Moleculares , Ratos , Ratos Wistar , Receptores de Serotonina/genética , Receptores 5-HT1 de Serotonina , Proteínas Recombinantes de Fusão/efeitos dos fármacos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Antagonistas da Serotonina/farmacologia , Sódio/metabolismo , Sódio/farmacologia , Transfecção
19.
J Cardiovasc Pharmacol ; 37(1): 78-88, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11152377

RESUMO

The I(Kr) blocker EGIS-7229 (S-21407), displays class Ib and class IV effects that may alter its pharmacologic profile compared with those of pure I(Kr) blockers. Therefore, the concentration- and frequency-dependent effects of EGIS-7229, and of the I(Kr) blockers d,l-sotalol and dofetilide, on the effective refractory period (ERP) were measured in isolated right ventricular papillary muscle of the rabbit in vitro. The effects of these drugs on right ventricular fibrillation threshold (RVFT) at increasing intravenous doses were also determined in anesthetized cats. Dofetilide and d,l-sotalol increased ERP in a concentration-dependent manner (dofetilide: 3-100 nM; d,l-sotalol: 3-100 microM) with strong reverse frequency dependence at high concentrations. EGIS-7229 concentration dependently lengthened ERP at 1-30 microM. Its effect on ERP was clearly reverse frequency dependent at 3 microM, but this feature of the drug diminished at 10 microM and was not apparent at 30 microM. The effect of EGIS-7229 (30 microM) on ERP was devoid of reverse frequency dependence as it was more effective (31%) than dofetilide (16 %) at high-pacing rate (3 Hz), whereas it was less effective (50%) than dofetilide (70%) at slow-pacing rate (1 Hz). Reverse frequency-dependent ERP effect of dofetilide (100 nM) was similarly abolished by the addition of lidocaine (30 microM). EGIS-7229 (1-8 mg/kg iv), d,l-sotalol (1-8 mg/kg iv), and dofetilide (10-80 microg/kg iv) caused a dose-dependent increase in RVFT. The minimum effective dose of d,l-sotalol and EGIS-7229 was 1 and 2 mg/kg, respectively, whereas that of dofetilide was 10 microg/kg. EGIS-7229 induced a smaller peak effect in RVFT than sotalol or dofetilide. In conclusion, EGIS-7229 markedly increased refractoriness to electrical stimulation in vitro and in vivo. Compared with pure I(Kr) blockers, the benefits of EGIS-7229 seem to be a greater lengthening of effective refractory period at rapid stimulation rates, suggesting a strong antiarrhythmic action, and a smaller effect at slow stimulation rates, suggesting low potential to induce early afterdepolarizations.


Assuntos
Antiarrítmicos/farmacologia , Hemodinâmica/efeitos dos fármacos , Fenetilaminas/farmacologia , Piridazinas/farmacologia , Sotalol/farmacologia , Sulfonamidas/farmacologia , Fibrilação Ventricular , Função Ventricular Direita/efeitos dos fármacos , Animais , Gatos , Relação Dose-Resposta a Droga , Estimulação Elétrica , Feminino , Hemodinâmica/fisiologia , Masculino , Músculos Papilares/efeitos dos fármacos , Músculos Papilares/fisiologia , Coelhos , Fibrilação Ventricular/tratamento farmacológico , Função Ventricular Direita/fisiologia
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