In vivo dopamine receptor agonist binding in rat brain: relation with pharmacological effects

The relation between in vivo rat striatal dopamine (DA) receptor binding of N,N-dipropyl-2-amino-5,6-dihydroxytetralin (DiPr-5,6-ADTN) and the dopaminergic effects of this compound was studied. The results indicate that maximal stereotyped biting and gnawing was associated with maximal saturable binding. At doses which maximally decreased striatal acidic DA metabolite concentrations a 25% or less occupation of binding sites was found. It is suggested that total in vivo binding is associated with stereotypy but not with the biochemical effects.