Dopamine receptor subtypes: in vivo biochemical evidence for functional interaction

SKF 38393, a selective D-1 dopamine (DA) agonist, enhanced the ability of spiperone, a D-2 antagonist, to increase rat striatal DA metabolite concentrations. Conversely, SKF 38393 reduced the abilities of pergolide and LY 171555, D-2 agonists, to decrease striatal DA metabolite concentrations. These findings are discussed in terms of a possible functional interaction between D-1 and D-2 DA receptors.