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1.
Crit Care Med ; 33(6): 1311-6, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15942349

RESUMO

OBJECTIVE: Hyperthermia is a potentially fatal manifestation of severe 3,4-methylenedioxymethamphetamine (MDMA, Ecstasy) intoxication. No proven effective drug treatment exists to reverse this potentially life-threatening hyperthermia, likely because mechanisms of peripheral thermogenesis are poorly understood. Using a rat model of MDMA hyperthermia, we evaluated the acute drug-induced changes in plasma catecholamines and used these results as a basis for the selection of drugs that could potentially reverse this hyperthermia. DESIGN: Prospective, controlled, randomized animal study. SETTING: A research institute laboratory. SUBJECTS: Male, adult Sprague-Dawley rats. INTERVENTIONS: Based on MDMA-induced changes in plasma catecholamine levels, rats were subjected to the nonselective (beta1 + beta2) adrenergic receptor antagonists propranolol or nadolol or the alpha1- + beta1,2,3-adrenergic receptor antagonist carvedilol before or after a thermogenic challenge of MDMA. MEASUREMENT AND MAIN RESULTS: Plasma catecholamines levels 30 mins after MDMA (40 mg/kg, subcutaneously) were determined by high-pressure liquid chromatography and electrochemical detection. Core temperature was measured by a rectal probe attached to a thermocouple. Four hours after MDMA treatment, blood was drawn and serum creatine kinase levels were measured as a marker of rhabdomyolysis using a Vitros analyzer. MDMA induced a 35-fold increase in norepinephrine levels, a 20-fold increase in epinephrine, and a 2.4-fold increase in dopamine levels. Propranolol (10 mg/kg, intraperitoneally) or nadolol (10 mg/kg, intraperitoneally) administered 30 mins before MDMA had no effect on the thermogenic response. In contrast, carvedilol (5 mg/kg, intraperitoneally) administered 15 mins before or after MDMA prevented this hyperthermic response. Moreover, when administered 1 hr after MDMA, carvedilol completely reversed established hyperthermia and significantly attenuated subsequent MDMA-induced creatine kinase release. CONCLUSION: These data show that alpha1 and beta3-adrenergic receptors may contribute to the mediation of MDMA-induced hyperthermia and that drugs targeting these receptors, such as carvedilol, warrant further investigation as novel therapies for the treatment of psychostimulant-induced hyperthermia and its sequelae.


Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Carbazóis/uso terapêutico , Febre/tratamento farmacológico , N-Metil-3,4-Metilenodioxianfetamina/intoxicação , Propanolaminas/uso terapêutico , Rabdomiólise/tratamento farmacológico , Análise de Variância , Animais , Carvedilol , Catecolaminas/sangue , Febre/induzido quimicamente , Febre/fisiopatologia , Masculino , Norepinefrina/sangue , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Rabdomiólise/induzido quimicamente , Rabdomiólise/fisiopatologia
2.
Br J Pharmacol ; 142(4): 667-70, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15159279

RESUMO

1. Studies were designed to examine the effects of alpha(1) (alpha(1)AR)- plus beta(3)-adrenoreceptor (beta(3)AR) antagonists on 3,4-methylenedioxymethamphetamine (MDMA, Ecstasy)-induced hyperthermia and measures of rhabdomyolysis (creatine kinase (CK)) and renal function (blood urea nitrogen (BUN) and serum creatinine (sCr)) in male Sprague-Dawley rats. 2. MDMA (40 mg x kg(-1), s.c.) induced a rapid and robust increase in rectal temperature, which was significantly attenuated by pretreatment with the alpha(1)AR antagonist prazosin (100 microg x kg(-1), i.p.) plus the beta(3)AR antagonist SR59230A (5 mg x kg(-1), i.p.). 3. CK levels significantly increased (peaking at 4 h) after MDMA treatment and were blocked by the combination of prazosin plus SR59230A. 4. At 4 h after MDMA treatment, BUN and sCr levels were also significantly increased and could be prevented by this combination of alpha(1)AR- plus beta(3)AR-antagonists. 5. The results from this study suggest that alpha(1)AR and beta(3)AR play a critical role in the etiology of MDMA-mediated hyperthermia and subsequent rhabdomyolysis.


Assuntos
N-Metil-3,4-Metilenodioxianfetamina/efeitos adversos , Receptores Adrenérgicos alfa 1/uso terapêutico , Receptores Adrenérgicos beta 3/uso terapêutico , Rabdomiólise/induzido quimicamente , Rabdomiólise/prevenção & controle , Antagonistas de Receptores Adrenérgicos alfa 1 , Antagonistas de Receptores Adrenérgicos beta 3 , Animais , Nitrogênio da Ureia Sanguínea , Temperatura Corporal/efeitos dos fármacos , Temperatura Corporal/fisiologia , Creatina Quinase/antagonistas & inibidores , Creatina Quinase/sangue , Esquema de Medicação , Quimioterapia Combinada , Febre/induzido quimicamente , Febre/fisiopatologia , Injeções Intraperitoneais , Injeções Subcutâneas , Masculino , N-Metil-3,4-Metilenodioxianfetamina/administração & dosagem , N-Metil-3,4-Metilenodioxianfetamina/antagonistas & inibidores , Prazosina/administração & dosagem , Prazosina/sangue , Prazosina/farmacocinética , Propanolaminas/administração & dosagem , Propanolaminas/sangue , Propanolaminas/farmacocinética , Ratos , Ratos Sprague-Dawley , Receptores Adrenérgicos alfa 1/administração & dosagem , Receptores Adrenérgicos beta 3/administração & dosagem , Fatores de Tempo
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