Characterization of stereospecific binding of 3H-(-) sulpiride, a selective antagonist at dopamine-D2 receptors, in rat CNS.
Sulpiride endowed with dopamine (DA)-antagonist properties, does not antagonize neostriatal DA-sensitive adenylyl cyclase activity either in vitro or in vivo. Sulpiride however is able to displace radioactive ligands, which label DA-receptors, from their specific binding sites. On these bases sulpiride has been proposed as a selective antagonist at dopamine-D2 receptors. We have characterized 3H(-) sulpiride stereospecific binding in various rat brain areas. In particular, 3H(-) sulpiride binding was found to be saturable, stereospecific and maximally enriched in the synaptic membrane fraction prepared from dopaminergic brain areas. Among a variety of compound tested only DA, DA-agonists and DA-antagonists were competitors for 3H(-) sulpiride specific binding sites. The results suggest that 3H(-) sulpiride may be an useful tool for the characterization and localization of dopamine D2-receptors.
D000818:Animals; D001921:Brain / Q000378:metabolism*; D003342:Corpus Striatum / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D008566:Membranes / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000378:metabolism*; D013237:Stereoisomerism; D013347:Subcellular Fractions / Q000378:metabolism; D013469:Sulpiride / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism
D011954:Receptors, Dopamine; D013469:Sulpiride