Striatal dopamine metabolism in response to apomorphine: the effects of repeated amphetamine pretreatment

The dose-dependent decrease in striatal dopamine (DA) metabolites following apomorphine (APO) administration was utilized as an index of changes in DA receptor sensitivity following the repeated administration of amphetamine (AMPH). The results suggest that: (a) repeated AMPH pretreatment does not alter DA autoreceptor sensitivity; and (b) interpretations of the decline in striatal DA metabolites at high doses of APO (greater than 50 micrograms/kg), in terms of activation of postsynaptic DA receptors, may require re-evaluation.