The characterization of [3H]sulpiride binding sites in pig striatal membranes

Pig striatal membranes have [3H]sulpiride-binding sites similar to those identified in rat striatal membranes. The pharmacological profile indicates that this binding is to dopamine receptors. Agonist displacement of [3H]sulpiride binding in pig striatal membranes is subject to guanine nucleotide regulation. This effect is mimicked by heat treatment. N-ethyl maleamide (20 microM) and dithioerythritol (3 mM) decrease agonist affinity for the [3H]sulpiride-binding site in pig striatal membranes without significantly affecting maximal displacement.