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1.
J Stud Alcohol Drugs ; 84(1): 97-102, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36799679

RESUMO

OBJECTIVE: This article presents the benzodiazepine concentrations in urine samples from participants undergoing alcohol withdrawal in a Phase 4 "Proof of Concept" double-blind, randomized, controlled clinical trial. Chlordiazepoxide was prescribed to all participants "as needed" during the first 2 weeks only of alcohol withdrawal, to prevent serious consequences such as seizures. The trial examined effects of either mifepristone or placebo on the primary trial outcomes, which included cognitive function tests at 3 weeks and 4 weeks after the cessation of drinking. Because benzodiazepines are known to affect memory, urine benzodiazepine concentrations were measured before cognitive testing. METHOD: Urine samples were collected from participants immediately before each cognitive testing session, and the concentrations of unconjugated benzodiazepines (i.e., compounds active at benzodiazepine receptors) were measured by standard assay, using mass spectrometry. RESULTS: The urine benzodiazepine measurements showed clearly that amounts of active benzodiazepine metabolites were present during the third and fourth weeks after the cessation of drinking that were as high as or higher than those seen after therapeutic dosing. CONCLUSIONS: The urinary benzodiazepine concentrations demonstrated that residual active benzodiazepine compounds can be present up to 2 weeks after the last ingestion. This could affect the results of cognitive testing in people with alcohol dependence undergoing detoxification.


Assuntos
Alcoolismo , Síndrome de Abstinência a Substâncias , Humanos , Benzodiazepinas , Alcoolismo/tratamento farmacológico , Síndrome de Abstinência a Substâncias/tratamento farmacológico , Transtorno da Personalidade Antissocial
2.
Pharmacol Rev ; 73(4): 127-154, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34663686

RESUMO

This review describes interactions between compounds, primarily dihydropyridines, that block L-type calcium channels and drugs that cause dependence, and the potential importance of these interactions. The main dependence-inducing drugs covered are alcohol, psychostimulants, opioids, and nicotine. In preclinical studies, L-type calcium channel blockers prevent or reduce important components of dependence on these drugs, particularly their reinforcing actions and the withdrawal syndromes. The channel blockers also reduce the development of tolerance and/or sensitization, and they have no intrinsic dependence liability. In some instances, their effects include reversal of brain changes established during drug dependence. Prolonged treatment with alcohol, opioids, psychostimulant drugs, or nicotine causes upregulation of dihydropyridine binding sites. Few clinical studies have been carried out so far, and reports are conflicting, although there is some evidence of effectiveness of L-channel blockers in opioid withdrawal. However, the doses of L-type channel blockers used clinically so far have necessarily been limited by potential cardiovascular problems and may not have provided sufficient central levels of the drugs to affect neuronal dihydropyridine binding sites. New L-type calcium channel blocking compounds are being developed with more selective actions on subtypes of L-channel. The preclinical evidence suggests that L-type calcium channels may play a crucial role in the development of dependence to different types of drugs. Mechanisms for this are proposed, including changes in the activity of mesolimbic dopamine neurons, genomic effects, and alterations in synaptic plasticity. Newly developed, more selective L-type calcium channel blockers could be of considerable value in the treatment of drug dependence. SIGNIFICANCE STATEMENT: Dependence on drugs is a very serious health problem with little effective treatment. Preclinical evidence shows drugs that block particular calcium channels, the L-type, reduce dependence-related effects of alcohol, opioids, psychostimulants, and nicotine. Clinical studies have been restricted by potential cardiovascular side effects, but new, more selective L-channel blockers are becoming available. L-channel blockers have no intrinsic dependence liability, and laboratory evidence suggests they reverse previously developed effects of dependence-inducing drugs. They could provide a novel approach to addiction treatment.


Assuntos
Bloqueadores dos Canais de Cálcio , Transtornos Relacionados ao Uso de Substâncias , Encéfalo/metabolismo , Cálcio/metabolismo , Canais de Cálcio Tipo L/metabolismo , Humanos , Neurônios/metabolismo
3.
Trials ; 21(1): 796, 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938477

RESUMO

BACKGROUND: Alcohol dependence is a significant issue contributing to disease burden. Changes in cortisol concentrations during alcohol withdrawal are associated with cognitive deficits and symptoms of depression. Current treatments are only successful for a small proportion of people and do not target cognitive deficits and symptoms of depression experienced by those who are alcohol dependent. The aim of this research is to determine the potential efficacy of mifepristone, a type II glucocorticoid receptor antagonist, to prevent symptoms of depression and cognitive deficits following alcohol detoxification. METHODS: This was a phase 2 therapeutic use trial. It was a double-blind randomised controlled clinical trial of mifepristone versus inactive placebo treatment. The trial aimed to recruit 120 participants who met the inclusion criteria: (1) male, (2) aged 18-60 years inclusive, and (3) alcohol dependent for 5 or more years. Participants were randomised to 600 mg a day mifepristone (200 mg morning, afternoon, and evening) for 7 days and 400 mg for the subsequent 7 days (200 mg morning and evening) or the equivalent number of placebo tablets for 14 days. Primary outcome measures were cognitive function (measured using the Cambridge Neuropsychological Test Automated Battery (CANTAB)) and symptoms of depression (measured using the Beck Depression Inventory (BDI)) at 4 weeks post-randomisation. RESULTS: Difficulties recruiting participants due to significant changes in the provision of inpatient care for alcohol dependence resulted in only 27 participants recruited to the trial, with data available for 21 participants. Fourteen participants were randomised to receive mifepristone and 13 to receive placebo. CONCLUSION: Larger trials would be needed to draw conclusions about the efficacy of mifepristone. TRIAL REGISTRATION: ISRCTN registry ISRCTN54001953 . Registered on 29 September 2011.


Assuntos
Alcoolismo , Alcoolismo/diagnóstico , Alcoolismo/tratamento farmacológico , Cognição , Depressão/diagnóstico , Depressão/tratamento farmacológico , Método Duplo-Cego , Humanos , Masculino , Mifepristona/efeitos adversos , Resultado do Tratamento
4.
BMC Psychiatry ; 16: 40, 2016 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-26912003

RESUMO

BACKGROUND: Increased levels of cortisol during acute alcohol withdrawal have been linked to cognitive deficits and depression. Preclinical research found that the glucocorticoid Type II receptor antagonist, mifepristone, prevented some of the neurotoxic effects of withdrawal and memory loss. Clinical trials have shown mifepristone effective in the treatment of depression. This study aims to examine the extent to which the glucocorticoid Type II receptor antagonist, mifepristone, when given to alcohol dependent males during the acute phase of alcohol withdrawal, will protect against the subsequent memory loss and depressive symptoms during abstinence from alcohol. METHODS/DESIGN: The study is a Phase 4 therapeutic use, "Proof of Concept" trial. The trial is a double-blind randomised controlled clinical trial of mifepristone versus inactive placebo. The trial aims to recruit 120 participants referred for an inpatient alcohol detoxification from community alcohol teams, who meet the inclusion criteria; 1) Male, 2) Aged 18-60 inclusive, 3) alcohol dependent for 5 or more years. A screening appointment will take place prior to admission to inpatient alcohol treatment units to ensure that the individual is suitable for inclusion in the trial in accordance with the inclusion and exclusion criteria. On admission participants are randomised to receive 600 mg a day of mifepristone (200 mg morning, afternoon and evening) for 7 days and 400 mg for the subsequent 7 days (200 mg morning and evening) or the equivalent number of placebo tablets for 14 days. Participants will remain in the trial for 4 weeks (at least 2 weeks as an inpatient) and will be followed up at 3, 6 and 12 months post randomisation. Primary outcome measures are cognitive function at week 3 and 4 after cessation of drinking and symptoms of depression over the 4 weeks after cession of drinking, measured using the Cambridge Neuropsychological Test Automated battery and Beck Depression Inventory, respectively. Secondary outcome measures are severity of the acute phase of alcohol withdrawal, alcohol craving, symptoms of protracted withdrawal and maintenance of abstinence and levels of relapse drinking at follow-up. DISCUSSION: The current trial will provide evidence concerning the role of glucocorticoid Type II receptor activation in cognitive function and depression during acute alcohol withdrawal and the efficacy of treatment with mifepristone. ISRCTN: ISRCTN54001953, Registered 29th September 2011.


Assuntos
Consumo de Bebidas Alcoólicas/tratamento farmacológico , Alcoólicos , Alcoolismo/tratamento farmacológico , Transtornos Cognitivos/tratamento farmacológico , Mifepristona/uso terapêutico , Síndrome de Abstinência a Substâncias/etiologia , Adulto , Alcoolismo/complicações , Transtornos Cognitivos/etiologia , Método Duplo-Cego , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Síndrome de Abstinência a Substâncias/prevenção & controle
5.
Alcohol ; 49(8): 811-6, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26003866

RESUMO

Chronic alcohol consumption disrupts glucocorticoid signaling at multiple physiological levels to interact with several disease-related processes associated with neuroendocrine and psychiatric disorders. Excessive alcohol use produces stress-related neuroadaptations at the level of the hypothalamic-pituitary-adrenal (HPA) axis as well as within central (extra-hypothalamic) neural circuitry, including the central amygdala (CeA) and prefrontal cortex (PFC). Altered glucocorticoid receptor (GR) signaling in these areas following excessive alcohol exposure is postulated to mediate the transition from recreational drinking to dependence, as well as the manifestation of a host of cognitive and neurological deficits. Specifically, a bidirectional regulation of stress systems by glucocorticoids leads to the development of an HPA axis tolerance and a concomitant sensitization of cortical and subcortical circuitries. A greater understanding of how hypothalamic and extra-hypothalamic glucocorticoid systems interact to mediate excessive drinking and related pathologies will lead to more effective therapeutic strategies for alcohol use disorder (AUD) and closely related comorbidities.


Assuntos
Alcoolismo/metabolismo , Glucocorticoides/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo , Receptores de Glucocorticoides/metabolismo , Consumo de Bebidas Alcoólicas/metabolismo , Consumo de Bebidas Alcoólicas/fisiopatologia , Alcoolismo/fisiopatologia , Tonsila do Cerebelo/fisiopatologia , Hormônio Liberador da Corticotropina/metabolismo , Fissura , Tolerância a Medicamentos , Regulação da Expressão Gênica , Humanos , Sistema Hipotálamo-Hipofisário/fisiopatologia , Vias Neurais/fisiopatologia , Sistema Hipófise-Suprarrenal/fisiopatologia , Córtex Pré-Frontal/fisiopatologia , Recidiva , Transdução de Sinais , Estresse Fisiológico
6.
Drug Alcohol Rev ; 28(4): 379-89, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19594792

RESUMO

INTRODUCTION AND AIMS: This paper describes the sociodemographic characteristics of 196 psychotic patients admitted to acute psychiatric wards in the UK, Denmark, Germany and Italy, with the aim of comparing comorbid with non-comorbid patients. DESIGN AND METHODS: It is a prospective field study with repeated measures at 1, 6 and 12 months. Patients were recruited from acute psychiatric wards in four European centres. They were grouped as comorbid or not on the basis of urine analysis. The Schedules for Clinical Assessment in Neuropsychiatry was used to provide a psychiatric diagnosis, and the Positive and Negative Symptom Severity Scale for further information on specific symptoms with results from the Fragerstrom test for nicotine dependence also reported. RESULTS: Comorbid patients were younger than those who were not but did not differ significantly in the other sociodemographic measures. Differences in sociodemographic characteristics of patients between centres were apparent. Comorbid patients had higher levels of positive and lower levels of negative symptoms than those who were non-comorbid. Differences were found in the patterns of drug use between comorbid patients who were using cannabis compared with those who were not. DISCUSSION AND CONCLUSIONS: Cross-cultural differences in the sociodemographic characteristics of the comorbid patient population give us a better insight into this heterogenous group.


Assuntos
Comparação Transcultural , Transtornos Psicóticos/complicações , Transtornos Relacionados ao Uso de Substâncias/complicações , Adulto , Fatores Etários , Diagnóstico Duplo (Psiquiatria) , Europa (Continente)/epidemiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Unidade Hospitalar de Psiquiatria/estatística & dados numéricos , Escalas de Graduação Psiquiátrica , Psicometria , Índice de Gravidade de Doença , Detecção do Abuso de Substâncias/métodos , Adulto Jovem
7.
Alcohol Clin Exp Res ; 32(12): 2107-16, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18828802

RESUMO

BACKGROUND: Studies were carried out to test the hypothesis that administration of a glucocorticoid Type II receptor antagonist, mifepristone (RU38486), just prior to withdrawal from chronic alcohol treatment, would prevent the consequences of the alcohol consumption and withdrawal in mice. MATERIALS AND METHODS: The effects of administration of a single intraperitoneal dose of mifepristone were examined on alcohol withdrawal hyperexcitability. Memory deficits during the abstinence phase were measured using repeat exposure to the elevated plus maze, the object recognition test, and the odor habituation/discrimination test. Neurotoxicity in the hippocampus and prefrontal cortex was examined using NeuN staining. RESULTS: Mifepristone reduced, though did not prevent, the behavioral hyperexcitability seen in TO strain mice during the acute phase of alcohol withdrawal (4 hours to 8 hours after cessation of alcohol consumption) following chronic alcohol treatment via liquid diet. There were no alterations in anxiety-related behavior in these mice at 1 week into withdrawal, as measured using the elevated plus maze. However, changes in behavior during a second exposure to the elevated plus maze 1 week later were significantly reduced by the administration of mifepristone prior to withdrawal, indicating a reduction in the memory deficits caused by the chronic alcohol treatment and withdrawal. The object recognition test and the odor habituation and discrimination test were then used to measure memory deficits in more detail, at between 1 and 2 weeks after alcohol withdrawal in C57/BL10 strain mice given alcohol chronically via the drinking fluid. A single dose of mifepristone given at the time of alcohol withdrawal significantly reduced the memory deficits in both tests. NeuN staining showed no evidence of neuronal loss in either prefrontal cortex or hippocampus after withdrawal from chronic alcohol treatment. CONCLUSIONS: The results suggest mifepristone may be of value in the treatment of alcoholics to reduce their cognitive deficits.


Assuntos
Consumo de Bebidas Alcoólicas/tratamento farmacológico , Glucocorticoides/antagonistas & inibidores , Antagonistas de Hormônios/uso terapêutico , Mifepristona/uso terapêutico , Síndrome de Abstinência a Substâncias/tratamento farmacológico , Consumo de Bebidas Alcoólicas/efeitos adversos , Animais , Glucocorticoides/análise , Antagonistas de Hormônios/farmacologia , Masculino , Transtornos da Memória/complicações , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/psicologia , Camundongos , Camundongos Endogâmicos C57BL , Mifepristona/farmacologia , Síndrome de Abstinência a Substâncias/complicações , Síndrome de Abstinência a Substâncias/psicologia
8.
Brain Res ; 1238: 12-22, 2008 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-18755165

RESUMO

Concentrations of corticosterone in brain areas of TO strain mice were measured by radioimmunoassay. The studies examined the effects of routine laboratory maneuvers, variation during the circadian peak, adrenalectomy, social defeat and acute injections of alcohol on these concentrations. Brief handling of mice increased corticosterone levels in plasma but not in striatum and reduced those in the hippocampus. Single injections of isotonic saline raised the plasma concentrations to a similar extent as the handling, but markedly elevated concentrations in the three brain regions. Five minutes exposure to a novel environment increased hippocampal and cerebral cortical corticosterone levels and striatal concentrations showed a larger rise. However, by 30 min in the novel environment, plasma concentrations rose further while those in striatum and cerebral cortex fell to control levels and hippocampal corticosterone remained elevated. Over the period of the circadian peak the hippocampal and striatal concentrations paralleled the plasma concentrations but cerebral cortical concentrations showed only small changes. Adrenalectomy reduced plasma corticosterone concentrations to below detectable levels after 48 h but corticosterone levels were only partially reduced in the hippocampus and striatum and remained unchanged in the cerebral cortex. Single or repeated social defeat increased both brain and plasma concentrations after 1 h. Acute injections of alcohol raised the regional brain levels in parallel with plasma concentrations. The results show that measurements of plasma concentrations do not necessarily reflect the levels in brain. The data also demonstrate that corticosterone levels can change differentially in specific brain regions. These results, and the residual hormone seen in the brain after adrenalectomy, are suggestive evidence for a local origin of central corticosterone.


Assuntos
Encéfalo/metabolismo , Corticosterona/metabolismo , Estresse Psicológico/metabolismo , Adrenalectomia , Animais , Encéfalo/fisiopatologia , Ritmo Circadiano , Dominação-Subordinação , Etanol/farmacologia , Masculino , Camundongos , Radioimunoensaio , Estresse Psicológico/fisiopatologia
9.
Pharmacol Biochem Behav ; 86(2): 234-45, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16930684

RESUMO

This review examines the evidence that glucocorticoids are involved, during both adolescence and adulthood, in the cognitive deficits caused by long-term alcohol consumption and in the mechanism(s) of alcohol dependence. During adolescence, the hypothalamopituitary-adrenal (HPA) axis undergoes well-characterized changes in basal activity and many of these are influenced by alcohol consumption. While the former have been fairly well studied, there is little information about whether alcohol effects on the HPA in adolescents differ from those in adults. The means by which glucocorticoids may influence alcohol-related neurotoxicity are presented, and potential differences between adolescence and adults in this regard noted. The substantial evidence for involvement of glucocorticoids in alcohol-induced cognitive deficits is described, with particular reference to the consequences of alcohol withdrawal. The use of immature organotypic cultures of rodent brain in the study of alcohol neurotoxicity is considered in detail, and the information obtained from this methodology concerning the role of glucocorticoid receptors and excitable membrane proteins in this neurotoxicity. The influence of glucocorticoids on alcohol consumption and possible contributions to alcohol dependence are then considered. In conclusion, more information concerning the effects of glucocorticoids on plasticity and alcohol neurotoxicity during the adolescent period is needed.


Assuntos
Adolescente/fisiologia , Consumo de Bebidas Alcoólicas/fisiopatologia , Consumo de Bebidas Alcoólicas/psicologia , Depressores do Sistema Nervoso Central/farmacologia , Etanol/farmacologia , Glucocorticoides/fisiologia , Adulto , Consumo de Bebidas Alcoólicas/efeitos adversos , Transtornos Cognitivos/induzido quimicamente , Transtornos Cognitivos/psicologia , Humanos , Síndrome de Abstinência a Substâncias/psicologia
10.
Brain Res ; 1082(1): 165-72, 2006 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-16510135

RESUMO

Elevations in circulating concentrations of glucocorticoids (GC) may increase the expression and/or sensitivity of ionotropic transmitter receptors in brain. For example, recent evidence suggests that acute and chronic GC exposure may alter the number and/or function of N-methyl-D-aspartate (NMDA)-type glutamate receptors, effects that may sensitize the brain to excitotoxic insults. The present studies examined the ability of short-term (24 h) corticosterone (CORT) exposure to potentiate NMDA-induced cytotoxicity in rat hippocampal slice cultures. Additional studies evaluated the role of mineralocorticoid (MR) and glucocorticoid receptor (GR) function, as well as de novo protein synthesis, in potentiation of toxicity by corticosterone exposure. Hippocampal slice cultures were exposed to NMDA (20 microM) for 24 h with cytotoxicity assessed by fluorescent detection of propidium iodide uptake. Exposure to NMDA caused significant propidium iodide uptake in each hippocampal region, while 24 h CORT (0.001-1 microM) exposure alone did not significantly increase propidium iodide uptake. Co-exposure of cultures to CORT and NMDA synergistically increased propidium iodide uptake in each hippocampal region, effects that were prevented by co-exposure to a non-toxic concentration of MK-801 (20 microM). In contrast, 24 h exposure with the MR antagonist spironolactone (1-10 microM), the GR antagonist RU-486 (1-10 microM), or the protein synthesis inhibitor cycloheximide (1 microM) failed to reduce the significant increase in propidium iodide uptake. These data suggest that relatively brief elevations in CORT levels may sensitize the hippocampus to injury independently of GC receptor activity and protein synthesis.


Assuntos
Corticosterona/farmacologia , Hipocampo/efeitos dos fármacos , N-Metilaspartato/farmacologia , Neurotoxinas/farmacologia , Análise de Variância , Animais , Animais Recém-Nascidos , Maleato de Dizocilpina/farmacologia , Interações Medicamentosas , Inibidores Enzimáticos/farmacologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Feminino , Técnicas In Vitro , Masculino , Propídio , Biossíntese de Proteínas/fisiologia , Ratos , Receptores de Glucocorticoides/fisiologia
11.
Brain Res Bull ; 68(3): 171-8, 2005 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-16325017

RESUMO

Effects of alterations in stress hormones and their actions were investigated on alcohol preference, by intraperitoneal administration of RU38486 (a Type II glucocorticoid receptor antagonist, also given by the intracerebroventricular route), spironolactone (a Type I glucocorticoid receptor antagonist), metyrapone (a corticosterone synthesis inhibitor), corticosterone, adrenocorticotropin (ACTH1-39), or intracerebroventricular injection of corticotropin releasing factor (CRF) or a CRF antagonist (alpha-helical CRF9-41). Intracerebroventricular or intraperitoneal administration of RU38486 did not alter the alcohol consumption of mice with high preference for alcohol, or, on first administration, the intake of those with low alcohol preference. When given by repeated intraperitoneal injection however this drug prevented the increase in alcohol consumption seen in "low preference" mice after 3 weeks vehicle injections. Spironolactone did not alter alcohol preference when given by intracerebroventricular or intraperitoneal routes. Repeated, but not single, administration of metyrapone reduced alcohol preference in both high and low preference animals and prevented the increase from low alcohol preference caused by repeated vehicle injections. ACTH1-39 or corticosterone administered by single or repeated intraperitoneal injection, or CRF given i.c.v., did not alter alcohol preference, but the CRF antagonist, alpha-helical CRF9-41, caused a transient increase from low alcohol preference. Blood corticosterone concentrations prior to preference measurements did not correlate with the alcohol preference of the mice. The results indicate that delayed consequences of corticosterone acting on Type II glucocorticoid receptors may be involved in the increases in alcohol preference after injection stress. They also suggest that central actions of CRF may influence the low alcohol consumption of the low alcohol-preferring mice.


Assuntos
Consumo de Bebidas Alcoólicas/psicologia , Depressores do Sistema Nervoso Central/administração & dosagem , Condicionamento Operante/efeitos dos fármacos , Etanol/administração & dosagem , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Hormônio Adrenocorticotrópico/farmacologia , Consumo de Bebidas Alcoólicas/fisiopatologia , Animais , Animais Recém-Nascidos , Comportamento Animal , Corticosterona/sangue , Corticosterona/farmacologia , Hormônio Liberador da Corticotropina/farmacologia , Esquema de Medicação , Inibidores Enzimáticos/administração & dosagem , Antagonistas de Hormônios/farmacologia , Metirapona/administração & dosagem , Camundongos , Mifepristona/farmacologia , Fatores de Tempo
12.
Alcohol Clin Exp Res ; 29(5): 871-81, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15897733

RESUMO

BACKGROUND: Evidence suggests that stress hormones (i.e., glucocorticoids) may be increased during acute or chronic consumption of ethanol and during withdrawal from ethanol consumption, effects that may contribute to the development of cognitive impairment. The goal of the current studies was to examine the hypothesis that increased glucocorticoid levels in conjunction with ethanol exposure and withdrawal may cause hippocampal damage. METHODS: Organotypic hippocampal slice cultures were exposed to 50 mM ethanol for 10 days and withdrawn for 1 day. After withdrawal, cytotoxicity and cytosolic Ca2+ accumulation were measured using the nucleic acid stain propidium iodide and Calcium Orange, AM, respectively. Cultures were also treated with nontoxic concentrations of corticosterone (0.001-1 microM) during ethanol exposure and withdrawal or only during withdrawal. Additional cultures were coexposed to corticosterone and RU486 (0.1-10.0 microM), spironolactone (0.1-10.0 microM), or MK-801 (20 microM) during ethanol exposure and/or withdrawal. RESULTS: Ethanol withdrawal did not increase propidium iodide fluorescence and cytosolic Ca2+ levels. However, significant increases in propidium iodide fluorescence and in cytosolic Ca2+ accumulation were observed in cultures when corticosterone (> or = 100 nM) was exposed during ethanol treatment and/or withdrawal. These effects of corticosterone on ethanol withdrawal were attenuated by RU486 and MK-801 but not by spironolactone coexposure. CONCLUSIONS: This report demonstrated that corticosterone exposure during ethanol treatment and/or withdrawal resulted in significant hippocampal damage, possibly via activation of glucocorticoid receptors and enhancement of the glutamatergic cascade. The findings from these studies suggest that glucocorticoids contribute to the neuropathological consequences of alcohol dependence in humans.


Assuntos
Cálcio/metabolismo , Depressores do Sistema Nervoso Central/efeitos adversos , Corticosterona/farmacologia , Citosol/metabolismo , Etanol/efeitos adversos , Hipocampo/metabolismo , Hipocampo/patologia , Síndrome de Abstinência a Substâncias/metabolismo , Síndrome de Abstinência a Substâncias/patologia , Animais , Corticosterona/antagonistas & inibidores , Citosol/efeitos dos fármacos , Feminino , Corantes Fluorescentes , Hipocampo/efeitos dos fármacos , Antagonistas de Hormônios/farmacologia , Masculino , Mifepristona/farmacologia , Antagonistas de Receptores de Mineralocorticoides/farmacologia , Técnicas de Cultura de Órgãos , Compostos Orgânicos , Propídio , Ratos , Ratos Sprague-Dawley , Receptores de Glucocorticoides/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/efeitos dos fármacos , Espironolactona/farmacologia
13.
Alcohol Clin Exp Res ; 29(3): 453-64, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15770122

RESUMO

This review contains the proceedings from a symposium held at the RSA conference in 2003 on "Alcohol Withdrawal and Conditioning." The presentations covered a range of interactions between conditioning and alcohol withdrawal, in both animal behavior and the clinic. Dr. D.N. Stephens first described his studies exploring the consequences of alcohol dependence and repeated experience of withdrawal on the conditioning process. His data suggested that repeated withdrawal from moderate alcohol intake impairs amygdala-dependent mechanisms for learning about aversive events. Dr. H. Becker then detailed studies examining the consequences of repeated ethanol withdrawal experience on subsequent ethanol drinking behavior in mice, and conditions in which motivational properties of odor cues that are associated with different phases of ethanol withdrawal influence such relapse behavior. The data suggested that cues associated with acute withdrawal or "recovery" from withdrawal may serve as modulating factors in influencing subsequent ethanol drinking behavior, and that the timing of the cues determines their consequences. Dr. F. Weiss described recent findings from animal models of relapse that suggested the efficacy of alcohol-associated contextual stimuli in eliciting alcohol-seeking behavior resembles the endurance of conditioned cue reactivity and cue-induced cocaine craving in humans. The interactive effects of stress and ethanol-related environmental stimuli were found to be dependent on concurrent activation of endogenous opioid and corticotropin-releasing factor systems. Conditioning factors (i.e., exposure to drug-associated stimuli) and stress could therefore interact to augment vulnerability to relapse. Dr. C. Drummond then addressed the clinical aspects of conditioning during alcohol withdrawal and described studies showing exposure of alcoholics to alcohol-related cues elicited greater subjective and physiological responses than exposure to neutral cues. The former responsivity showed a relationship with a measure of motivation to drink alcohol. Finally, Dr. C. Cunningham provided a summary of the concepts involved in the presentations and discussed the conditioning processes that affect behavior during and after alcohol withdrawal.


Assuntos
Depressores do Sistema Nervoso Central/efeitos adversos , Condicionamento Operante/efeitos dos fármacos , Etanol/efeitos adversos , Síndrome de Abstinência a Substâncias/psicologia , Consumo de Bebidas Alcoólicas/psicologia , Alcoolismo/psicologia , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Ratos
15.
Alcohol Clin Exp Res ; 27(2): 354-61, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12605085

RESUMO

This symposium focused on functional alterations in the mesolimbic dopamine system during the abstinence phase after chronic alcohol intake. Mark Brodie first described his recordings from midbrain slices prepared after chronic alcohol treatment in vivo by daily injection in C57BL/6J mice. No changes were found in the baseline firing frequency of dopaminergic neurones in the VTA (ventral tegmental area), but the excitation produced in these neurones by an acute ethanol challenge was significantly increased in neurons from ethanol-treated mice compared with those from the saline-treated controls. There was also a significant decrease in the inhibitory response to GABA by the dopamine neurones following the chronic ethanol treatment. These data suggest that the timing pattern and mode of ethanol administration may determine the types of changes observed in dopaminergic reward area neurons. Annalisa Muntoni lectured on the relationship between electrophysiological and biochemical in vivo evidence supporting a reduction in tonic activity of dopamine neurons projecting to the nucleus accumbens at various times after suspension of chronic ethanol treatment and morphological changes affecting dopamine neurons in rat VTA. Hilary J. Little then described changes in dopaminergic neurone function in the VTA during the abstinence phase. Decreases in baseline firing were seen at 6 days after withdrawal of mice from chronic ethanol treatment but were not apparent after 2 months abstinence. Increases in the affinity of D1 receptors in the striatum, but not in the cerebral cortex, were seen however up to 2 months after withdrawal. Scott Steffensen then described his studies recording in vivo from GABA containing neurones in the VTA in freely moving rats. Chronic ethanol administration enhanced the baseline activity of these neurones and resulted in tolerance to the inhibition by ethanol of these neurones. His results demonstrated selective adaptive circuit responses within the VTA or in extrategmental structures that regulate VTA-GABA neurone activity.


Assuntos
Delirium por Abstinência Alcoólica/fisiopatologia , Transtornos do Sistema Nervoso Induzidos por Álcool/fisiopatologia , Dano Encefálico Crônico/fisiopatologia , Etanol/toxicidade , Delirium por Abstinência Alcoólica/patologia , Transtornos do Sistema Nervoso Induzidos por Álcool/patologia , Animais , Dano Encefálico Crônico/patologia , Dopamina/fisiologia , Humanos , Sistema Límbico/patologia , Sistema Límbico/fisiopatologia , Mesencéfalo/patologia , Mesencéfalo/fisiopatologia , Camundongos , Camundongos Endogâmicos C57BL , Rede Nervosa/patologia , Rede Nervosa/fisiopatologia , Transmissão Sináptica/efeitos dos fármacos , Área Tegmentar Ventral/patologia , Área Tegmentar Ventral/fisiopatologia , Ácido gama-Aminobutírico/fisiologia
18.
Brain Res ; 930(1-2): 111-22, 2002 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-11879801

RESUMO

Four dihydropyridine calcium channel antagonists were compared for their ability to protect against the hyperexcitability produced in mice by withdrawal from chronic ethanol treatment and to protect against seizures due to bicuculline or pentylenetetrazol. Comparison was also made of their effects on locomotor activity, body temperature and motor co-ordination, and with the corresponding effects of the benzodiazepine, diazepam. Nitrendipine, nimodipine, nicardipine (at 50 and 10 mg/kg) and isradipine (at 10 and 4 mg/kg) decreased the withdrawal hyperexcitability, but showed no anticonvulsant action against either bicuculline or pentylenetetrazol. Diazepam (1.5 and 4 mg/kg) both protected against the withdrawal signs and decreased seizure incidence after bicuculline and pentylenetetrazol, although the latter effects were of shorter duration than those on the withdrawal signs. The four dihydropyridines decreased spontaneous locomotor activity, an effect which lasted up to 6 h. Only isradipine and diazepam had any ataxic actions at the doses tested. All the dihydropyridines had hypothermic actions, considerably shorter in duration than effects on withdrawal hyperexcitability, with little evidence of dose dependence, except for nicardipine, which had a larger, dose-related, hypothermic action. Of the four compounds, isradipine was more potent in terms of dose, but not any more selective for effectiveness against the withdrawal signs, than the other three dihydropyridines, and nicardipine was slightly less effective in protecting against the withdrawal signs. The results indicate that the anticonvulsant effects of the dihydropyridines were selective for ethanol withdrawal hyperexcitability, whereas diazepam showed no such selectivity.


Assuntos
Bloqueadores dos Canais de Cálcio/uso terapêutico , Depressores do Sistema Nervoso Central/efeitos adversos , Di-Hidropiridinas/uso terapêutico , Etanol/efeitos adversos , Síndrome de Abstinência a Substâncias/tratamento farmacológico , Animais , Anticonvulsivantes/farmacologia , Anticonvulsivantes/uso terapêutico , Ataxia/tratamento farmacológico , Ataxia/psicologia , Comportamento Animal/efeitos dos fármacos , Bicuculina/farmacologia , Temperatura Corporal/efeitos dos fármacos , Convulsivantes , Antagonistas GABAérgicos/farmacologia , Hipnóticos e Sedativos/farmacologia , Hipnóticos e Sedativos/uso terapêutico , Masculino , Camundongos , Atividade Motora/efeitos dos fármacos , Pentilenotetrazol/antagonistas & inibidores , Convulsões/induzido quimicamente , Convulsões/prevenção & controle , Síndrome de Abstinência a Substâncias/psicologia
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