RESUMO
The behavioral and neurochemical effects of four intraventricular infusions of octopamine (3,200 micrograms), tryptophan (800 micrograms), and octopamine plus tryptophan delivered over 6 hours was studied in rats after performing a portacaval anastomosis or a sham operation. After each infusion, each animal was rated for neurologic depression with a 17 point test battery. Although overt coma was not induced, octopamine infusions severely depressed neurologic function. Concentrations of norepinephrine, dopamine, and serotonin in the brain were significantly decreased after the infusion of octopamine. Levels of norepinephrine in the brain were significantly correlated with neurologic status and greater depletion of norepinephrine was associated with greater neurologic depression. These studies demonstrate that infusing large amounts of the trace amine octopamine depresses behavior in the rat and this depression is most closely associated with depletion of stores of norepinephrine in the brain.
Assuntos
Comportamento Animal/efeitos dos fármacos , Inibição Neural/efeitos dos fármacos , Octopamina/farmacologia , Animais , Comportamento Animal/fisiologia , Química Encefálica/efeitos dos fármacos , Ácido Hidroxi-Indolacético/metabolismo , Injeções Intraventriculares , Masculino , Octopamina/administração & dosagem , Octopamina/metabolismo , Derivação Portocava Cirúrgica , Distribuição Aleatória , Ratos , Ratos Endogâmicos , Reflexo/efeitos dos fármacos , Reflexo/fisiologia , Serotonina/metabolismo , Fatores de Tempo , Triptofano/administração & dosagem , Triptofano/metabolismo , Triptofano/farmacologiaRESUMO
A 30% surface area, full-thickness, open-flame burn of guinea pigs induced significant anorexia and rapid loss of body weight. Analysis of regional brain concentrations of amine neurotransmitters suggested burn-specific elevation of serotonergic neurotransmission, reduction of dopamine metabolism, and elevation of norepinephrine concentrations in brain areas thought to control feeding. These data suggest that specific regional aberrations in each of these amine neurotransmitters may contribute to the anorexia associated with major thermal injury.
