title: In vitro binding of the very potent and selective D-2 dopamine agonist, [3H]N-0437 to calf caudate membranes.
abstract: N-0437, a non-catecholic aminotetralin has recently been described as a very potent and selective dopamine D-2 agonist. In this study the in vitro binding of [3H]N-0437 (specific activity 80.6 Ci/mmol) to calf caudate membranes is described. It was found that [3H]N-0437 binds with a high affinity (KD = 0.17 nM) and a low proportion of non-specific binding. Moreover the binding was saturable with a high number of binding sites (Bmax = 703 +/- 28 fmol/mg protein) and reversible (dissociation half-time = 68 min). Pharmacological analysis of [3H]N-0437 binding showed that it was selective for dopamine receptors and that it was also stereoselective for D-2 receptors. Non-dopaminergic drugs were without exception very poor displacers. Taken together the results suggest that [3H]N-0437 labels dopamine D-2 receptors with a high selectivity in the calf brain, and thus, that it should be a useful tool in studies of central dopamine receptors.
mesh_terms: D000818:Animals; D002417:Cattle; D002421:Caudate Nucleus / Q000378:metabolism*; D003342:Corpus Striatum / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D008566:Membranes / Q000378:metabolism; D009281:Naphthalenes / Q000378:metabolism*; D011954:Receptors, Dopamine / Q000378:metabolism*; D013134:Spiperone / Q000494:pharmacology; D013764:Tetrahydronaphthalenes / Q000378:metabolism* / Q000494:pharmacology; D013876:Thiophenes / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D009281:Naphthalenes; D011954:Receptors, Dopamine; D013764:Tetrahydronaphthalenes; D013876:Thiophenes; D013134:Spiperone; C047508:rotigotine