Chronic D-amphetamine and phencyclidine: effects on dopamine agonist and antagonist binding sites in the extrapyramidal and mesolimbic systems.

Dopamine agonist and antagonist binding to rat striatal and mesolimbic region tissue was examined in rats chronically treated with D-amphetamine or phencyclidine. In striatum, D-amphetamine produces a down-regulation of [3H]spiroperidol binding but an increase in [3H]ADTN bound (measured in the absence of ascorbate). This suggests that [3H]spiroperidol and [3H]ADTN bind to distinct, separate sites which can be independently regulated.