title: Agonist interactions with dopamine receptors: focus on radioligand-binding studies.
abstract: Radioligand-binding experiments have demonstrated that both D-1 (adenylate cyclase stimulatory) and D-2 (adenylate cyclase inhibitory) dopamine receptors demonstrate high- and low-affinity agonist-binding states. Under appropriate conditions, both D-1 and D-2 high-affinity binding states can be labeled directly with 3H-labeled agonists. Previous studies that identified a portion of high-affinity 3H-labeled agonist binding as a distinct dopamine receptor subclass (D-3 or autoreceptor) were, in fact, labeling the high-affinity agonist-binding state of postsynaptic D-1 receptors.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D001667:Binding, Competitive; D002417:Cattle; D003342:Corpus Striatum / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D006892:Hydroxydopamines / Q000494:pharmacology; D010903:Pituitary Gland, Anterior / Q000378:metabolism; D011869:Radioligand Assay; D051381:Rats; D011954:Receptors, Dopamine / Q000378:metabolism*; D012110:Reserpine / Q000494:pharmacology; D013134:Spiperone
chemical_list: D006892:Hydroxydopamines; D011954:Receptors, Dopamine; D013134:Spiperone; D006160:Guanosine Triphosphate; D012110:Reserpine; D000262:Adenylyl Cyclases; D004298:Dopamine