[3H]-Domperidone labels only a single population of receptors which convert from high to low affinity for dopamine in rat brain

Abstract

Dopamine recognized and competed for a single population of [³H]-domperidone-binding sites in rat striatum and olfactory tubercle when tested in the presence of sodium ions and guanine nucleotide [Gpp(NH)p]. In the absence of Na⁺ and Gpp(NH)p, however, dopamine recognized two components of [³H]-domperidone binding. Thus, [³H]-domperidone labelled only a single population of dopamine receptors (type D₂) which fully converted from high to low affinity for dopamine. These results agree with those found previously using [³H]-spiperone and [³H]-YM-09151-2.