RESUMO
OBJECTIVES: This study was conducted to determine the effects of carvedilol adjunct to standard treatment on left ventricular function (LVF), estimated as ejection fraction (EF) and fractional shortening (FS) on echocardiography, in children with idiopathic dilated cardiomyopathy (DCM). A secondary end point was to characterize the antioxidant potential of carvedilol. METHODS: Hospitalized children aged
Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Carbazóis/uso terapêutico , Cardiomiopatia Dilatada/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Propanolaminas/uso terapêutico , Função Ventricular Esquerda/efeitos dos fármacos , Administração Oral , Adolescente , Antagonistas Adrenérgicos beta/administração & dosagem , Pressão Sanguínea/efeitos dos fármacos , Carbazóis/administração & dosagem , Cardiomiopatia Dilatada/sangue , Cardiomiopatia Dilatada/fisiopatologia , Carvedilol , Catalase/sangue , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Glutationa Peroxidase/sangue , Glutationa Redutase/sangue , Frequência Cardíaca/efeitos dos fármacos , Humanos , Lactente , Masculino , Propanolaminas/administração & dosagem , Estudos Prospectivos , Volume Sistólico/efeitos dos fármacos , Superóxido Dismutase/sangue , Resultado do Tratamento , Função Ventricular Esquerda/fisiologiaRESUMO
Balanced and coordinated antioxidant defence enzyme activities are of utmost importance for correct physiological function and for shielding against unwelcome pathological conditions. We determined the activities of copper-zinc superoxide dismutase (CuZnSOD), catalase, glutathione peroxidase and glutathione reductase in erythrocytes isolated from patients receiving different therapy (streptokinase alone or in combination with metoprolol or with carvedilol) for up to 168 hr after starting treatment for acute myocardial infarction. We observed increased CuZnSOD activity in erythrocytes isolated from patients treated with streptokinase-carvedilol (after 6, 24 and 168 hr) and in erythrocytes isolated from patients treated with streptokinase-metoprolol (after 24 hr). In addition, positive correlation between CuZnSOD and catalase activities was found in erythrocytes isolated from patients that received streptokinase-carvedilol after 168 hr. As metoprolol does not react directly with hydrogen peroxide, it would appear that combined streptokinase-metoprolol therapy exerted its effects primarily via by beta-blockade whereas combined streptokinase-carvedilol therapy appeared to function via both beta-blockade and direct antioxidant mechanisms.