RESUMO
Methylphenidate is commonly used for the treatment of attention deficit/hyperactivity disorder. There are still few works regarding the effects of methylphenidate on brain energy metabolism. Thus, in the present study we evaluated the effect of chronic administration of methylphenidate on the activities of mitochondrial respiratory chain complexes I and III in the brain of young rats. The effect of acute administration of methylphenidate on mitochondrial respiratory chain complexes I, II, III and IV in the brain of young rats was also investigated. For acute administration, a single injection of methylphenidate was given to rats on postnatal day 25. For chronic administration, methylphenidate injections were given starting at postnatal day 25 once daily for 28 days. Our results showed that complexes I and III were not affected by chronic administration of methylphenidate. Moreover, the acute administration of methylphenidate decreased complex I activity in cerebellum and prefrontal cortex, whereas complexes II, III and IV were not altered.
Assuntos
Transporte de Elétrons/efeitos dos fármacos , Metilfenidato/administração & dosagem , Mitocôndrias/efeitos dos fármacos , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Cerebelo/efeitos dos fármacos , Cerebelo/metabolismo , Complexo I de Transporte de Elétrons/efeitos dos fármacos , Complexo III da Cadeia de Transporte de Elétrons/efeitos dos fármacos , Masculino , Metilfenidato/farmacologia , Mitocôndrias/metabolismo , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , RatosRESUMO
Methylphenidate (MPH) is frequently prescribed for the treatment of attention deficit/hyperactivity disorder. It was previously demonstrated that MPH altered brain metabolic activity. Most cell energy is obtained through oxidative phosphorylation, in the mitochondrial respiratory chain. However, there are still few studies about MPH effects on the brain of adult rats. Thus, in the present study we evaluated the effect of acute or chronic administration of MPH on the activities of mitochondrial respiratory chain complexes I-IV in the brain of adult rats. For acute administration, a single injection of MPH was given to 60-day-old rats. For chronic administration, MPH injections were given to 60-day-old rats once daily for 28 days. Our results showed that complexes I, II, III and IV were inhibited after acute or chronic MPH administration in the hippocampus, prefrontal cortex, striatum and cerebral cortex. On the other hand, cerebellum was not affected.
