Haloperidol prevents the methamphetamine-induced apomorphine subsensitivity of dopamine metabolism in rat striatum.

Our previous experiment showed that the sensitivity of striatal dopaminergic metabolism to apomorphine was lowered after pretreating rats with methamphetamine. This study further demonstrated that haloperidol administered with methamphetamine prevented the effect of the methamphetamine pretreatment. Since gamma-butyrolactone was administered in combination with apomorphine so as to remove complications which might arise from the modification of impulse flow through the striatonigral feedback loop, it is possible that the observed effect of apomorphine upon striatal dopaminergic metabolism and its antagonism with haloperidol may be mediated by autoreceptors of dopaminergic axon terminals in rat striatum.