Guanyl nucleotides decrease antagonist binding at high affinity dopamine receptors.

Guanyl nucleotides induce a loss of high affinity [3H]spiroperidol binding sites in rat striatum that can be demonstrated by rate association, equilibrium dissociation and saturation analyses. [3H]Spiroperidol is an antagonist ligand for rat striatal dopamine receptors. These data therefore demonstrate clear cut effects of guanyl nucleotides on antagonist binding.