Effect of haloperidol and d-amphetamine on cerebral tyramine and octopamine levels

The administration of d-amphetamine or haloperidol produced a marked reduction in the rat striatum concentration of p-tyramine, an effect that was not observed in the mesolimbic system. However, the administration of d-amphetamine to haloperidol-pretreated animals produced in both brain areas a marked reduction in p-tyramine levels. Furthermore, this latter treatment produced a marked increase in the m-tyramine levels in both brain regions. Hypothalamic p-octopamine levels were reduced by d-amphetamine, but not by haloperidol or haloperidol in the presence of d-amphetamine.