Binding of [3H]U-101958 to sigma1 receptor-like sites in human cerebellum and neuroblastoma cells.
1-Benzyl-4-[N-(3-isopropoxy-2-pyridinyl)-N-methyl]-amino-piperidine ([3H]U-101958), a dopamine D4 receptor ligand, was found to bind to a large sigma1 receptor-like component in human cerebellum and SK-N-MC neuroblastoma cells with high affinity (2-4 nM Kd). By contrast, binding to dopamine D4 receptors represented 10% or less of the sigma1 receptor-like site. Considering that U-101958 has been characterized as either a dopamine D4 receptor agonist or antagonist, depending on the system under study, the observation that U-101958 also binds to sigma1 receptor-like sites is important for accurate interpretation of the pharmacological actions of this compound. [3H]U-101958 may be a useful radioligand for sigma1 rather than dopamine D4 receptor sites.
D000631:Aminopyridines / Q000378:metabolism*; D001667:Binding, Competitive; D002531:Cerebellum / Q000378:metabolism*; D046508:Culture Techniques; D015259:Dopamine Agents / Q000378:metabolism*; D006801:Humans; D009447:Neuroblastoma / Q000378:metabolism*; D010880:Piperidines / Q000378:metabolism*; D011869:Radioligand Assay; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D050638:Receptors, Dopamine D4; D017480:Receptors, sigma / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000097605:Sigma-1 Receptor