RESUMO
We have previously reported time dependent and dose dependent changes in the rat dopaminergic receptor system following chronic administration of cocaine (upregulation of cacaina, D1, and DA-uptake sites). We have now evaluated the effects of chronic cacaine exposure on the central catecholamine/indolamine neurotransmitter systems. Groups of rats were injected with cocaine (15 mg/kg, i.p, b.i.d.) or saline for 1,3,7,14 or 21 days. Cortical and striatal tissues were analysed for morepinephrine, dopamine, serotomin and their primary metabolites using a HPLC-ECD method. Chronic administration of cacaine did not change the cortical and striatal concentrations of the neurotransmitters under study; except, for a transient increase in the cortical MHPG concentration on day 3. These results suggest that changes in the dopaminergic receptor system following chronic cocaine exposure are not to changes in the neurotransmitter concentrations
Assuntos
Ratos , Animais , Monoaminas Biogênicas , Cocaína/administração & dosagem , Neurotransmissores , RatosRESUMO
El tratamiento crónico con cloruro de manganeso (5 mg Mn/kg/día), durante 9 semanas, no afectó la unión del radioligando [3H]-quinuclidinil benzilato a los receptores colinérgicos muscarínicos en el cerebro de ratón. Mediante técnica autorradiográfica se determinó la localización anatómica precisa de los receptores y se procedió a la cuantificació de los mismos en los cortes coronales del bulbo olfatorio y del cerebro medio. A la luz de los resultados obtenidos podemos concluir que, en nuestras condiciones experimentales, no se producen alteraciones en la densidad de los receptores colinérgicos muscarínicos en el cerebro de ratones intoxicados con manganeso