Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Retina ; 35(9): 1765-71, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25923955

RESUMO

PURPOSE: To investigate homocysteine (Hcy) concentration in the blood plasma and the vitreous in patients with exudative age-related macular degeneration receiving intravitreal anti-vascular endothelial growth factor therapy. METHODS: Plasma Hcy and vitreous Hcy levels were analyzed in 73 exudative age-related macular degeneration patients (50.7% received pegaptanib 0.3 mg and 50.3% received ranibizumab 0.5 mg) and compared with 80 controls and 40 patients with idiopathic epiretinal membranes, respectively. Homocysteine concentration was measured by immunonephelometric particle test, and it was determined before and after antiangiogenic therapy. RESULTS: The mean Hcy concentrations (± SD) of blood plasma and vitreous were 13.0 ± 4.2 µmol/L and 1.00 ± 0.3 µmol/L in patients treated with pegaptanib; in ranibizumab group, they were 12.8 ± 2.5 µmol/L and 1.4 ± 0.6 µmol/L, respectively. The results of plasma and vitreous Hcy indicated statistically significant differences between exudative age-related macular degeneration patients and control groups (P = 0.03 and P = 0.02). After 6 months with both intravitreal therapies, the plasma and vitreous Hcy concentrations did not change significantly (P = 0.1). CONCLUSION: Pegaptanib and ranibizumab did not increase the plasma or vitreous Hcy concentrations.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Aptâmeros de Nucleotídeos/uso terapêutico , Homocisteína/sangue , Ranibizumab/uso terapêutico , Corpo Vítreo/metabolismo , Degeneração Macular Exsudativa/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Exsudatos e Transudatos , Feminino , Humanos , Injeções Intravítreas , Masculino , Pessoa de Meia-Idade , Nefelometria e Turbidimetria , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Degeneração Macular Exsudativa/sangue
2.
Physiol Behav ; 133: 152-60, 2014 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-24878312

RESUMO

Novelty-seeking in rodents, defined as enhanced specific exploration of novel situations, is considered to predict the response of animals to drugs of abuse and, thus, allow "drug-vulnerable" individuals to be identified. The main objective of this study was to assess the predictive ability of two well-known paradigms of the novelty-seeking trait - novelty-induced locomotor activity (which distinguishes High- and Low-Responder mice, depending on their motor activity) and the hole-board test (which determines High- and Low-Novelty Seeker mice depending on the number of head dips they perform) - to identify subjects that would subsequently be more sensitive to the conditioned rewarding effects of cocaine in a population of young adult (PND 56) and adolescent (PND 35) OF1 mice of both sexes. Conditioned place preference (CPP), a useful tool for evaluating the sensitivity of individuals to the incentive properties of addictive drugs, was induced with a sub-threshold dose of cocaine (1 mg/kg, i.p.). Our results showed that novelty-induced motor activity had a greater predictive capacity to identify "vulnerable-drug" individuals among young-adult mice (PND 56), while the hole-board test was more effective in adolescents (PND 35). High-NR young-adults, which presented higher motor activity in the first ten minutes of the test (novelty-reactivity), were 3.9 times more likely to develop cocaine-induced CPP than Low-NR young-adults. When total activity (1h) was evaluated (novelty-habituation), only High-R (novelty-non-habituating) young-adult male and Low-R (novelty-habituating) female mice produced a high conditioning score. However, only High-Novelty Seeker male and female adolescents and Low-Novelty Seeker female young-adult animals (according to the hole-board test), acquired cocaine-induced CPP. These findings should contribute to the development of screening methods for identifying at-risk human drug users and prevention strategies for those with specific vulnerabilities.


Assuntos
Cocaína/administração & dosagem , Condicionamento Operante/efeitos dos fármacos , Inibidores da Captação de Dopamina/administração & dosagem , Atividade Motora/efeitos dos fármacos , Recompensa , Fatores Etários , Análise de Variância , Animais , Comportamento Exploratório/efeitos dos fármacos , Feminino , Modelos Lineares , Masculino , Camundongos , Tempo de Reação/efeitos dos fármacos
3.
PLoS One ; 9(3): e92576, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24658541

RESUMO

The aim of the present study was to investigate if a novelty-seeking phenotype mediates the long-lasting consequences of intermittent EtOH intoxication during adolescence. The hole board test was employed to classify adolescent mice as High- or Low-Novelty Seekers. Subsequently, animals were administered ethanol (1.25 or 2.5 g/kg) on two consecutive days at 48-h intervals over a 14-day period. Anxiety levels--measured using the elevated plus maze- spontaneous motor activity and social interaction test were studied 3 weeks later. A different set of mice underwent the same procedure, but received only the 2.5 g/kg dose of ethanol. Three weeks later, in order to induce CPP, the same animals were administered 1 or 6 mg/kg of cocaine or 1 or 2.5 mg/kg MDMA. The results revealed a decrease in aggressive behaviors and an anxiolytic profile in HNS mice and longer latency to explore the novel object by LNS mice. Ethanol exposure enhanced the reinforcing effects of cocaine and MDMA in both groups when CPP was induced with a sub-threshold dose of the drugs. The extinguished cocaine-induced CPP (1 and 6 mg/kg) was reinstated after a priming dose in HNS animals only. Our results confirm that intermittent EtOH administration during adolescence induces long-lasting effects that are manifested in adult life, and that there is an association between these effects and the novelty-seeking phenotype.


Assuntos
Comportamento Animal/efeitos dos fármacos , Etanol/farmacologia , Comportamento Exploratório/efeitos dos fármacos , Adolescente , Envelhecimento/fisiologia , Animais , Ansiedade , Cocaína/farmacologia , Humanos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , N-Metil-3,4-Metilenodioxianfetamina/farmacologia , Fenótipo , Reforço Psicológico
4.
Food Chem ; 148: 268-75, 2014 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-24262556

RESUMO

The effects of five technological procedures and of the contents of total anthocyanins and condensed tannins on 19 fermentation-related aroma compounds of young red Mencia wines were studied. Multifactor ANOVA revealed that levels of those volatiles changed significantly over the length of storage in bottles and, to a lesser extent, due to other technological factors considered; total anthocyanins and condensed tannins also changed significantly as a result of the five practices assayed. Five aroma compounds possessed an odour activity value >1 in all wines, and another four in some wines. Linear correlation among volatile compounds and general phenolic composition revealed that total anthocyanins were highly related to 14 different aroma compounds. Multifactor ANOVA, considering the content of total anthocyanins as a sixth random factor, revealed that this parameter affected significantly the contents of ethyl lactate, ethyl isovalerate, 1-pentanol and ethyl octanoate. Thus, the aroma of young red Mencia wines may be affected by levels of total anthocyanins.


Assuntos
Fenóis/química , Vitis/microbiologia , Vinho/análise , Fermentação , Odorantes/análise , Fenóis/metabolismo , Vitis/química , Compostos Orgânicos Voláteis/análise , Vinho/microbiologia , Leveduras/metabolismo
5.
Artigo em Inglês | MEDLINE | ID: mdl-23959085

RESUMO

Numerous reports have highlighted the role of the endocannabinoid system in the addictive potential of MDMA (3,4-methylenedioxy-methamphetamine). A previous report showed that CB1 knockout (KOCB1) mice do not acquire MDMA self-administration, despite developing conditioned place preference (CPP). This contradiction could be due to the particular procedure of place conditioning used. The present work compares MDMA-induced CPP in KOCB1 mice using unbiased and biased procedures of place conditioning. In the unbiased procedure, MDMA induced CPP and reinstatement of the extinguished preference in wild type (WT) mice, but not in KOCB1 mice. In contrast, in a biased protocol of CPP, MDMA produced preference in both types of mice. The anxiolytic response induced by MDMA in the elevated plus maze (EPM) was observed only in KOCB1 mice and may have been responsible, at least partially, for the CPP in the biased procedure. A neurochemical analysis revealed that KOCB1 mice presented higher striatal DA and DOPAC levels in response to MDMA, but no alterations in their levels of monoamine transporters. In line with previous self-administration studies, our data suggest that CB1 receptors play an important role in the reinforcing effects of MDMA, and that the experimental procedure of CPP employed should be taken into account when drawing conclusions.


Assuntos
Condicionamento Operante/fisiologia , Alucinógenos/efeitos adversos , N-Metil-3,4-Metilenodioxianfetamina/efeitos adversos , Receptor CB1 de Canabinoide/metabolismo , Transtornos Relacionados ao Uso de Substâncias/patologia , Transtornos Relacionados ao Uso de Substâncias/fisiopatologia , Ácido 3,4-Di-Hidroxifenilacético/metabolismo , Análise de Variância , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Condicionamento Operante/efeitos dos fármacos , Modelos Animais de Doenças , Dopamina/metabolismo , Relação Dose-Resposta a Droga , Ácido Homovanílico/metabolismo , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Camundongos , Camundongos Knockout , Receptor CB1 de Canabinoide/deficiência , Reforço Psicológico , Fatores de Tempo
6.
Neuropharmacology ; 75: 172-80, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23916480

RESUMO

This study examined the role of cannabinoid CB1 receptors (CB1r) in aggressive behavior. Social encounters took place in grouped and isolated mice lacking CB1r (CB1KO) and in wild-type (WT) littermates. Cognitive impulsivity was evaluated in the delayed reinforcement task (DRT). Gene expression analyses of monoaminooxidase-A (MAO-A), catechol-o-methyl-transferase (COMT), 5-hydroxytriptamine transporter (5-HTT) and 5-HT1B serotonergic receptor (5HT1Br) in the median and dorsal raphe nuclei (MnR and DR, respectively) and in the amygdala (AMY) were performed by real time-PCR. Double immunohistochemistry studies evaluated COMT and CB1r co-localization in the raphe nuclei and in the cortical (ACo), basomedian (BMA) and basolateral (BLA) amygdaloid nuclei. The behavioral effects of the CB1r agonist ACEA (1 and 2 mg/kg) on aggression were also evaluated in isolated OF1 mice. CB1KO mice housed in groups showed higher levels of offensive aggression. Isolation increased aggressive behavior only in WT. In grouped CB1KO mice COMT gene expression was significantly higher in the MnR and DR, while MAO-A gene expression was lower in the MnR. Gene expression of 5HT1Br, COMT and MAO-A was higher in the amygdala of CB1KO mice. CB1r double-immunohistochemistry revealed cytoplasmic-labeled COMT-ir cells in the raphe nuclei and in the ACo, BMA and BLA. CB1r immunolabeling was observed only in ACo, BMA and BLA, where it was localized in axons and buttons. The density of labeled processes increased in BLA. Acute administration of the CB1 agonist ACEA (2 mg/kg) significantly decreased the aggression levels of OF1 mice. These results suggest that CB1r plays an important role in social interaction and aggressive behavior.


Assuntos
Agressão/fisiologia , Receptor CB1 de Canabinoide/metabolismo , Agressão/efeitos dos fármacos , Tonsila do Cerebelo/metabolismo , Animais , Ácidos Araquidônicos/farmacologia , Agonistas de Receptores de Canabinoides/farmacologia , Catecol O-Metiltransferase/genética , Catecol O-Metiltransferase/metabolismo , Condicionamento Operante/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Comportamento Impulsivo/induzido quimicamente , Relações Interpessoais , Masculino , Camundongos , Camundongos Knockout , Monoaminoxidase/genética , Monoaminoxidase/metabolismo , Núcleos da Rafe/metabolismo , Receptor CB1 de Canabinoide/deficiência , Receptor 5-HT1B de Serotonina/genética , Receptor 5-HT1B de Serotonina/metabolismo , Reforço Psicológico , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Fatores de Tempo
7.
Artigo em Inglês | MEDLINE | ID: mdl-23533488

RESUMO

Previous reports have shown that several of the effects of morphine, including the development of tolerance and physical withdrawal symptoms, are reduced by extracts of Brugmansia arborea (L.) Lagerheim (Solanaceae) (B. arborea). In the present study we evaluate the action of the methanol extract of B. arborea (7.5-60 mg/kg) on the motor and reinforcing effects of morphine (20 and 40 mg/kg) and cocaine (25 mg/kg) using the conditioned place preference (CPP) procedure. At the doses employed, B. arborea did not affect motor activity or induce any effect on CPP. The extract partially counteracted morphine-induced motor activity and completely blocked the CPP induced by 20 mg/kg morphine. On the other hand, B. arborea blocked cocaine-induced hyperactivity but did not block cocaine-induced CPP. Reinstatement of extinguished preference with a priming dose of morphine or cocaine was also inhibited by B. arborea. The complex mechanism of action of B. arborea, which affects the dopaminergic and the cholinergic systems, seems to provide a neurobiological substrate for the effects observed. Considered as a whole, these results point to B. arborea as a useful tool for the treatment of morphine or cocaine abuse.

8.
Toxicology ; 311(1-2): 78-86, 2013 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-23246480

RESUMO

The early neonatal stage constitutes a sensitive period during which exposure to adverse events can increase the risk of neuropsychiatric disorders. Maternal deprivation (MD) is a model of early life stress that induces long-term behavioural and physiological alterations, including susceptibility to different drugs of abuse. In the present study we have used the conditioned place preference (CPP) paradigm to address the influence of MD on the rewarding effects of 3,4-methylenedioxymetamphetamine (MDMA) in adolescent animals of both sexes. We have previously observed in adolescent rats that MD induces modifications in the serotonergic and endocannabinoid systems, which play a role in the rewarding effects of MDMA. In light of this evidence, we hypothesized that MD would alter the psychobiological consequences of exposure to MDMA. Neonatal Wistar rats underwent MD (24h, on PND 9) or were left undisturbed (controls). The animals were conditioned with 2.5mg/kg MDMA during the periadolescent period (PND 34-PND 43) and were tested in the open-field test at the end of adolescence (PND 60). Animals were sacrificed on PND 68-75 and levels of serotonin (5-HT) and its metabolite 5-hydroxyindole acetic acid were measured in the striatum, hippocampus and cortex, while the expression of hippocampal CB1 cannabinoid receptor (CB1R) and circulating levels of corticosterone and leptin were also measured. Control males showed CPP after administration of MDMA. However, no MDMA-induced CPP was detected in control females or MD males, and MD had no effect on open field activity in any group. A reduction in striatal and cortical 5-HT levels, increased expression of hippocampal CB1R and a marked trend towards higher circulating leptin levels were observed in MDMA-treated MD males. Our results demonstrate for the first time that MD reduces the rewarding effects of MDMA in a sex-dependent manner. We propose that this effect is related, at least in part, with alterations of the serotonergic and cannabinoid systems.


Assuntos
Química Encefálica/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Condicionamento Clássico/efeitos dos fármacos , Privação Materna , N-Metil-3,4-Metilenodioxianfetamina/toxicidade , Caracteres Sexuais , Envelhecimento/efeitos dos fármacos , Envelhecimento/fisiologia , Animais , Encéfalo/metabolismo , Química Encefálica/fisiologia , Condicionamento Clássico/fisiologia , Feminino , Masculino , Ratos , Ratos Wistar
9.
PLoS One ; 7(8): e43107, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22916213

RESUMO

BACKGROUND: The rewarding effects of 3,4-methylenedioxy-metamphetamine (MDMA) have been demonstrated in conditioned place preference (CPP) procedures, but the involvement of the dopaminergic system in MDMA-induced CPP and reinstatement is poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: In this study, the effects of the DA D1 antagonist SCH 23390 (0.125 and 0.250 mg/kg), the DA D2 antagonist Haloperidol (0.1 and 0.2 mg/kg), the D2 antagonist Raclopride (0.3 and 0.6 mg/kg) and the dopamine release inhibitor CGS 10746B (3 and 10 mg/kg) on the acquisition, expression and reinstatement of a CPP induced by 10 mg/kg of MDMA were evaluated in adolescent mice. As expected, MDMA significantly increased the time spent in the drug-paired compartment during the post-conditioning (Post-C) test, and a priming dose of 5 mg/kg reinstated the extinguished preference. The higher doses of Haloperidol, Raclopride and CGS 10746B and both doses of SCH 23390 blocked acquisition of the MDMA-induced CPP. However, only Haloperidol blocked expression of the CPP. Reinstatement of the extinguished preference was not affected by any of the drugs studied. Analysis of brain monoamines revealed that the blockade of CPP acquisition was accompanied by an increase in DA concentration in the striatum, with a concomitant decrease in DOPAC and HVA levels. Administration of haloperidol during the Post-C test produced increases in striatal serotonin, DOPAC and HVA concentrations. In mice treated with the higher doses of haloperidol and CGS an increase in SERT concentration in the striatum was detected during acquisition of the CPP, but no changes in DAT were observed. CONCLUSIONS/SIGNIFICANCE: These results demonstrate that, in adolescent mice, the dopaminergic system is involved in the acquisition and expression of MDMA-induced CPP, but not in its reinstatement.


Assuntos
Condicionamento Operante/efeitos dos fármacos , Dopamina/metabolismo , N-Metil-3,4-Metilenodioxianfetamina/farmacologia , Animais , Benzazepinas/farmacologia , Western Blotting , Antagonistas de Dopamina/farmacologia , Haloperidol/farmacologia , Masculino , Camundongos , Racloprida/farmacologia , Serotonina/metabolismo , Tiazepinas/farmacologia
10.
Pharmacol Biochem Behav ; 102(1): 124-32, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22507913

RESUMO

Novelty-seeking in rodents, defined as enhanced specific exploration of novel situations, is considered to predict the response of animals to drugs of abuse and, thus, identify "drug-vulnerable" individuals. The main objective of this work was to determine the capacity of two animal models-the novel object recognition task and the novel environment test-for evaluating to what extent novelty-seeking can predict greater sensitivity to the rewarding properties of cocaine in young adult (PND 56) and adolescent (PND 35) OF1 mice of both sexes. Conditioned place preference, a useful tool for evaluating the sensitivity of individuals to the incentive properties of addictive drugs, was induced with a sub-threshold dose of cocaine (1 mg/kg, i.p.). Three factors that predispose individuals to addiction were considered: age, sex and novelty-seeking trait. CPP was detected only in the young adults that spent most time exploring the novel environment (High Novel Environment Seekers, High-Environment-NS). The novel environment test seemed to be more effective than the novel object recognition task in identifying young adults vulnerable to drugs; specifically, it revealed a distinction between High- and Low-Environment-NS mice that predicted greater sensitivity to the rewarding properties of cocaine among young adults but not among adolescents. Although our results reveal a higher novelty preference among young adult females than among their male counterparts in the two NS tests, both sexes showed similar susceptibility to the rewarding effects of a sub-threshold dose of cocaine in the CPP. These findings suggest that screening can identify humans at-risk of becoming drug users, and may contribute to the development of prevention strategies based on specific vulnerabilities.


Assuntos
Cocaína/farmacologia , Condicionamento Psicológico/efeitos dos fármacos , Comportamento Exploratório/efeitos dos fármacos , Recompensa , Animais , Condicionamento Psicológico/fisiologia , Comportamento Exploratório/fisiologia , Feminino , Masculino , Camundongos , Valor Preditivo dos Testes , Tempo de Reação/efeitos dos fármacos , Tempo de Reação/fisiologia
11.
Addict Biol ; 17(3): 588-600, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21995421

RESUMO

Many adolescents often take ethanol (EtOH) in combination with 3,4-methylenedioxymethylamphetamine (MDMA). In the present work, we used a mouse model to study the effect of repeated pre-exposure during adolescence to EtOH (2 g/kg), MDMA (10 or 20 mg/kg) or EtOH + MDMA on the rewarding and reinstating effects of MDMA in the conditioned place preference (CPP) paradigm. Pre-exposure to EtOH, MDMA or both increased the rewarding effects of a low dose of MDMA (1.25 mg/kg). These pre-treatments did not affect the acquisition of the CPP induced by 5 mg/kg of MDMA. However, the CPP was more persistent in mice pre-exposed to both doses of MDMA or to EtOH + MDMA20. After extinction of the CPP induced by 5 mg/kg of MDMA, reinstatement was observed in all groups with a priming dose of 2.5 mg/kg of MDMA, in the groups pre-exposed to EtOH or MDMA alone with a priming dose of 1.25 mg/kg, and in the groups pre-treated with MDMA alone with a priming dose of 0.625 mg/kg. Pre-treatment during adolescence with MDMA or EtOH induced long-term changes in the level of biogenic amines [dihydroxyphenyl acetic acid, homovanillic acid, dopamine turnover, serotonin (5-hydroxytryptamine, 5-HT) and 5-hydroxyindole acetic acid (5-HIAA) in the striatum, and 5-HT and 5-HIAA in the cortex] after the first reinstatement test, although these effects depended on the dose used during conditioning. These results suggest that exposure to EtOH and MDMA during adolescence reinforces the addictive properties of MDMA.


Assuntos
Depressores do Sistema Nervoso Central/farmacologia , Condicionamento Psicológico/efeitos dos fármacos , Etanol/farmacologia , N-Metil-3,4-Metilenodioxianfetamina/farmacologia , Recompensa , Serotoninérgicos/farmacologia , Animais , Aminas Biogênicas/metabolismo , Córtex Cerebral/metabolismo , Corpo Estriado/metabolismo , Extinção Psicológica/efeitos dos fármacos , Masculino , Camundongos
12.
Behav Brain Funct ; 6: 19, 2010 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-20307280

RESUMO

BACKGROUND: Numerous reports indicate that MDMA users consume other psychoactive drugs, among which cannabis is one of the most common. The aim of the present study was to evaluate, using the conditioned place preference, the effect of the cannabinoid agonist WIN 55,212-2 on the rewarding effects of MDMA in mice. METHODS: In the first experiment adolescent mice were initially conditioned with 1.25, 2.5 or 5 mg/kg of MDMA or 0.1 or 0.5 mg/kg of WIN and subsequently with both drugs. Reinstatement of the extinguished preference by priming doses was performed in the groups that showed CPP. In the second experiment, animals were conditioned with 2.5 or 5 mg/kg of MDMA and, after extinction, reinstatement of the preference was induced by 0.5 or 0.1 mg/kg of WIN. RESULTS: A low dose of WIN 55212-2 (0.1 mg/kg) increased the rewarding effects of low doses of MDMA (1.25 mg/kg), although a decrease in the preference induced by MDMA (5 and 2.5 mg/kg) was observed when the dose of WIN 55212-2 was raised (0.5 mg/kg). The CB1 antagonist SR 141716 also increased the rewarding effects of the lowest MDMA dose and did not block the effects of WIN. Animals treated with the highest WIN dose plus a non-neurotoxic dose of MDMA exhibited decreases of striatal DA and serotonin in the cortex. On the other hand, WIN 55212-2-induced CPP was reinstated by priming injections of MDMA, although WIN did not reinstate the MDMA-induced CPP. CONCLUSIONS: These results confirm that the cannabinoid system plays a role in the rewarding effects of MDMA and highlights the risks that sporadic drug use can pose in terms of relapse to dependence. Finally, the potential neuroprotective action of cannabinoids is not supported by our data; on the contrary, they are evidence of the potential neurotoxic effect of said drugs when administered with MDMA.


Assuntos
Benzoxazinas/farmacologia , Condicionamento Psicológico/efeitos dos fármacos , Morfolinas/farmacologia , N-Metil-3,4-Metilenodioxianfetamina/farmacologia , Naftalenos/farmacologia , Receptor CB1 de Canabinoide/agonistas , Serotoninérgicos/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Química Encefálica/efeitos dos fármacos , Bloqueadores dos Canais de Cálcio/farmacologia , Relação Dose-Resposta a Droga , Interações Medicamentosas , Extinção Psicológica/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos , Fármacos Neuroprotetores/farmacologia , Piperidinas/farmacologia , Pirazóis/farmacologia , Receptor CB1 de Canabinoide/antagonistas & inibidores , Receptor CB1 de Canabinoide/metabolismo , Recompensa , Rimonabanto
13.
Eur J Gastroenterol Hepatol ; 22(6): 651-61, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19641467

RESUMO

Chronic liver inflammation after murine bile duct ligation could evolve according to three interrelated phenotypes, which would have different metabolic, functional and histologic characteristics. Liver injury secondary to extrahepatic cholestasis would induce an early ischemic-reperfusion phenotype with cholangiocyte depolarization, abnormal ion transport, hypometabolism with anaerobic glycolysis and hepatocytic apoptosis. This phenotype, in turn, could trigger the switch to a leukocytic phenotype by the cholangiocytes, with an intense anaplerotic activity, hypermetabolism, extracellular matrix degradation and moderated proliferation to create a pseudotissue with metabolic autonomy and paracrine functions. In the long-term cholestasis-drive tumorigenesis, the tumorous tissue would principally consist of cholangiocyte parenchyma, with an impressive biosynthetic activity through the tricarboxylic cell cycle. In terms of the tumorous stroma, made up by fibroplasia and angiogenesis, it would favor the tumor trophism. In conclusion, the great intensity and persistence in the expression of these phenotypes by the cholestatic cholangiocyte would favor chronic inflammatory tumorigenesis.


Assuntos
Neoplasias dos Ductos Biliares/etiologia , Ductos Biliares/patologia , Transformação Celular Neoplásica/patologia , Colestase Extra-Hepática/complicações , Colestase Intra-Hepática/complicações , Neoplasias Hepáticas/etiologia , Animais , Apoptose , Ductos Biliares/fisiopatologia , Transformação Celular Neoplásica/metabolismo , Colestase Extra-Hepática/patologia , Colestase Extra-Hepática/fisiopatologia , Colestase Intra-Hepática/patologia , Colestase Intra-Hepática/fisiopatologia , Modelos Animais de Doenças , Glicólise , Hepatite/etiologia , Hepatite/patologia , Hepatite/fisiopatologia , Humanos , Ligadura , Cirrose Hepática Biliar/etiologia , Cirrose Hepática Biliar/patologia , Neoplasias Hepáticas/patologia , Camundongos , Neovascularização Patológica/etiologia , Neovascularização Patológica/patologia , Neovascularização Patológica/fisiopatologia , Ratos , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/fisiopatologia
14.
Addict Biol ; 14(4): 447-56, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19740367

RESUMO

Those who take ecstasy are more likely to consume other drugs than non-users with cocaine abuse being reported by 75.5% of high school student MDMA (+/- 3,4-methylenedioxymetamphetamine hydrochloride) users. The aim of this work was to evaluate the effects of exposure during adolescence to MDMA, cocaine or to both drugs on the MDMA-induced conditioned place preference (CPP) in adult mice. Animals received two daily administrations of saline, 10 mg/kg of MDMA, 25 mg/kg of cocaine or 10 mg/kg of MDMA plus 25 mg/kg of cocaine over 3 days (from PD28 to 30). Three weeks after pre-treatment, the MDMA-induced CPP procedure was initiated (PD52). Acquisition of CPP was induced with a sub-threshold dose of MDMA (1.25 mg/kg) only in animals treated during adolescence with MDMA alone. Preference was established in all the groups after conditioning with 10 mg/kg of MDMA, while the time required to achieve extinction was longer in those pre-treated with cocaine or MDMA alone (46 and 28 sessions, respectively). Moreover, preference was reinstated with progressively lower priming doses of MDMA in mice pre-treated with MDMA or cocaine alone. These results demonstrate that early exposure to MDMA or cocaine induces long-lasting changes that last until adulthood and modify the response of animals to MDMA.


Assuntos
Comportamento de Escolha/efeitos dos fármacos , Cocaína/farmacologia , Condicionamento Psicológico/efeitos dos fármacos , Alucinógenos/farmacologia , N-Metil-3,4-Metilenodioxianfetamina/farmacologia , Fatores Etários , Animais , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Alucinógenos/administração & dosagem , Masculino , Camundongos , N-Metil-3,4-Metilenodioxianfetamina/administração & dosagem
15.
Physiol Behav ; 96(4-5): 620-30, 2009 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-19150452

RESUMO

Rats allowed extended access to cocaine self-administration develop a number of symptoms of addiction, such as greater susceptibility to drug-induced relapse. Using the conditioned place preference (CPP), the number of conditioning training sessions was increased in order to augment exposure to contextual cues associated with the effects of a drug. Mice were conditioned with a steady dose of 6 or 25 mg/kg of cocaine for 4, 8, 12, 16, 20 or 40 days. Weekly sessions of extinction followed the establishment of preference, after which a priming dose of cocaine was administered to reinstate the extinguished preference. The magnitude of the place preference effect was equal in all groups, independently of the number of conditioning sessions. The persistence of the place preference was not related with the number of sessions. Higher responsiveness to reinstatement of the extinguished preference occurred only with an intermediate number of conditioning sessions. In this way, the relation between the number of training sessions and vulnerability to relapse appeared to follow an inverted U-shaped function. Our results suggest that increasing the number of conditioning sessions from 12 to up to 16, without increasing the amount of drug administered, can be of great use in the study of vulnerability to relapse.


Assuntos
Aprendizagem por Associação/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Cocaína/farmacologia , Condicionamento Clássico/efeitos dos fármacos , Inibidores da Captação de Dopamina/farmacologia , Análise de Variância , Animais , Comportamento Aditivo/fisiopatologia , Relação Dose-Resposta a Droga , Meio Ambiente , Extinção Psicológica/efeitos dos fármacos , Estudos Longitudinais , Masculino , Camundongos , Estatísticas não Paramétricas , Fatores de Tempo
16.
FEBS J ; 274(15): 3948-59, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17635582

RESUMO

Soluble inorganic pyrophosphatases (inorganic diphosphatases, EC 3.6.1.1) were isolated and characterized from three phylogenetically diverse cyanobacteria--Synechocystis sp. PCC 6803, Anabaena sp. PCC 7120, and Pseudanabaena sp. PCC 6903--and one anoxygenic photosynthetic bacterium, Rhodopseudomonas viridis (purple nonsulfur). These enzymes were found to be family I soluble inorganic pyrophosphatases with c. 20 kDa subunits with diverse oligomeric structures. The corresponding ppa genes were cloned and functionally validated by heterologous expression. Cyanobacterial family I soluble inorganic pyrophosphatases were strictly Mg(2+)-dependent enzymes. However, diverse cation cofactor dependence was observed for enzymes from other groups of photosynthetic bacteria. Immunochemical studies with antibodies to cyanobacterial soluble inorganic pyrophosphatases showed crossreaction with orthologs of other main groups of phototrophic prokaryotes and suggested a close relationship with the enzyme of heliobacteria, the nearest photosynthetic relatives of cyanobacteria. A slow-growing Escherichia coli JP5 mutant strain, containing a very low level of soluble inorganic pyrophosphatase activity, was functionally complemented up to wild-type growth rates with ppa genes from diverse photosynthetic prokaryotes expressed under their own promoters. Overall, these results suggest that the bacterial family I soluble inorganic pyrophosphatases described here have retained functional similarities despite their genealogies and their adaptations to diverse metabolic scenarios.


Assuntos
Chlorobi/enzimologia , Chromatiaceae/enzimologia , Cianobactérias/enzimologia , Bactérias Gram-Negativas/enzimologia , Pirofosfatase Inorgânica/classificação , Pirofosfatase Inorgânica/metabolismo , Fotossíntese , Chlorobi/genética , Chromatiaceae/genética , Cromatografia em Gel , Cianobactérias/genética , Bactérias Gram-Negativas/genética , Pirofosfatase Inorgânica/genética , Pirofosfatase Inorgânica/isolamento & purificação , Cinética , Oxigênio/metabolismo , Filogenia , Solubilidade
17.
Neuropsychopharmacology ; 32(8): 1750-9, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17299518

RESUMO

Although the rewarding effects of 3,4-methylenedioxy-metamphetamine (MDMA) have been demonstrated in self-administration and conditioned place preference (CPP) procedures, its addictive potential (ie, the vulnerability to relapse, measured by its ability to induce reinstatement of an extinguished response), remains poorly understood. In this study, the effects of MDMA (5, 10, and 20 mg/kg) on the acquisition, extinction and reinstatement of CPP were evaluated in mice, using two different protocols during acquisition of CPP. In the first experiment, animals were trained using a two-session/day schedule (MDMA and saline for 4 consecutive days), whereas in the second experiment, they were trained using an alternating day schedule (MDMA and saline each 48 h). After extinction, the ability of drug priming to reinstate CPP was evaluated. In Experiment 1, MDMA did not significantly increase the time spent in the drug-paired compartment during the post-conditioning (Post-C) test, although the preference was evident a week afterwards, lasting between 2 and 21 weeks. No reinstatement was observed after MDMA priming. In Experiment 2, all doses produced CPP in Post-C, which lasted between 1 and 4 weeks. MDMA induces reinstatement at doses up to 4 times lower than those used in conditioning. The analyses of brain monoamines revealed that the daily schedule of treatment induces a non-dose-dependent decrease in dopamine and serotonin (5-HT) in the striatum, whereas the alternating schedule produces a dose-dependent decrease of 5-HT in the cortex. These results demonstrate that MDMA produces long-lasting rewarding effects and reinstatement after extinction, suggesting the susceptibility of this drug to induce addiction.


Assuntos
Condicionamento Operante/efeitos dos fármacos , Alucinógenos/farmacologia , N-Metil-3,4-Metilenodioxianfetamina/farmacologia , Recompensa , Análise de Variância , Animais , Animais Recém-Nascidos , Comportamento Animal/efeitos dos fármacos , Aminas Biogênicas/metabolismo , Química Encefálica/efeitos dos fármacos , Relação Dose-Resposta a Droga , Extinção Psicológica/efeitos dos fármacos , Masculino , Camundongos , Ratos , Esquema de Reforço
20.
Biochem J ; 395(1): 211-21, 2006 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-16313235

RESUMO

Two sPPases (soluble inorganic pyrophosphatases, EC 3.6.1.1) have been isolated from the microalga Chlamydomonas reinhardtii. Both are monomeric proteins of organellar localization, the chloroplastic sPPase I [Cr (Ch. reinhardtii)-sPPase I, 30 kDa] is a major isoform and slightly larger protein than the mitochondrial sPPase II (Cr-sPPase II, 24 kDa). They are members of sPPase family I and are encoded by two different cDNAs, as demonstrated by peptide mass fingerprint analysis. Molecular phylogenetic analyses indicated that Cr-sPPase I is closely related to other eukaryotic sPPases, whereas Cr-sPPase II resembles its prokaryotic counterparts. Chloroplastic sPPase I may have replaced a cyanobacterial ancestor very early during plastid evolution. Cr-sPPase II orthologues are found in members of the green photosynthetic lineage, but not in animals or fungi. These two sPPases from photosynthetic eukaryotes are novel monomeric family I sPPases with different molecular phylogenies and cellular localizations.


Assuntos
Chlamydomonas reinhardtii/enzimologia , Pirofosfatase Inorgânica/metabolismo , Fotossíntese , Sequência de Aminoácidos , Animais , Arabidopsis/enzimologia , Chlamydomonas reinhardtii/metabolismo , Cloroplastos/enzimologia , Clonagem Molecular , DNA Complementar/genética , Escherichia coli/genética , Expressão Gênica , Pirofosfatase Inorgânica/química , Dados de Sequência Molecular , Filogenia , Regiões Promotoras Genéticas/genética , Isoformas de Proteínas , Transporte Proteico , Alinhamento de Sequência
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA