WAY-100635 is a potent dopamine D4 receptor agonist
- 548 Downloads
Rationale and objectives
WAY-100635 is a prototypical 5-HT1A receptor antagonist and has been used widely as a pharmacological probe to investigate the distribution and function of 5-HT1A receptors. Results from our studies suggested that WAY-100635 was potently inducing effects unrelated to its 5-HT1A receptor affinity. In the present work, we evaluated the in vitro pharmacology of this compound at two D2-like receptor subtypes.
The functional properties and binding affinities of WAY-100635 were evaluated in HEK 293 cells stably expressing dopamine D2L or D4.4 receptors.
Initial screens performed by the NIMH Psychoactive Drug Screening Program indicated that WAY-100635 displayed 940, 370, and 16 nM binding affinities at D2L, D3, and D4.2 receptors, respectively. Subsequent saturation analyses demonstrated that the K d of [3H]WAY-100635 at D4.2 receptors was 2.4 nM, only tenfold higher than 5-HT1A. WAY-100635 and its major metabolite, WAY-100634, were potent agonists in HEK-D4.4 cells (EC50=9.7±2.2 and 0.65±0.2 nM, respectively). WAY-100635 behaved as a full agonist, and WAY-100634 was a nearly full agonist. In HEK-D2L cells, WAY-100635 weakly antagonized the effects of 300 nM quinpirole. Subsequent radioligand binding studies confirmed that WAY-100635 possesses high affinity for D4.4 receptors but binds weakly to D2L receptors (3.3±0.6 and 420±11 nM, respectively).
This study demonstrates that WAY-100635 is not a “selective” 5-HT1A receptor antagonist, as previously reported, and conclusions drawn from studies that employed WAY-100635 as a selective 5-HT1A antagonist may need to be reevaluated.
KeywordsWAY-100635 WAY-100634 5-HT1A D4 D2 Receptor selectivity
This research was supported by NIH grant DA02189 from NIDA (DEN), MH60397 from NIMH (VJW), the NIMH-PDSP, and KO2MH01366 (BLR). The work was conducted in a facility constructed with support from Research Facilities Improvement Program Grant Number C06-14499 from the National Center for Research Resources of the National Institutes of Health. We also thank Stewart Frescas for the synthesis of WAY-100635, WAY-100634, and A-381393 used in this study.
- Cliffe IA (2000) A retrospect on the discovery of WAY-100635 and the prospect for improved 5-HT(1A) receptor PET radioligands. Nucl Med Biol 27:441–447Google Scholar
- Fletcher A, Forster EA, Bill DJ, Brown G, Cliffe IA, Hartley JE, Jones DE, McLenachan A, Stanhope KJ, Critchley DJ, Childs KJ, Middlefell VC, Lanfumey L, Corradetti R, Laporte AM, Gozlan H, Hamon M, Dourish CT (1996) Electrophysiological, biochemical, neurohormonal and behavioural studies with WAY-100635, a potent, selective and silent 5-HT1A receptor antagonist. Behav Brain Res 73:337–353PubMedCrossRefGoogle Scholar
- Johansson L, Sohn D, Thorberg SO, Jackson DM, Kelder D, Larsson LG, Renyi L, Ross SB, Wallsten C, Eriksson H, Hu PS, Jerning E, Mohell N, Westlind-Danielsson A (1997) The pharmacological characterization of a novel selective 5-hydroxytryptamine1A receptor antagonist, NAD-299. J Pharmacol Exp Ther 283:216–225PubMedGoogle Scholar
- Nakane M, Cowart MD, Hsieh GC, Miller L, Uchic ME, Chang R, Terranova MA, Donnelly-Roberts DL, Namovic MT, Miller TR, Wetter JM, Marsh K, Stewart AO, Brioni JD, Moreland RB (2005) 2-[4-(3,4-Dimethylphenyl)piperazin-1-ylmethyl]-1H benzoimidazole (A-381393), a selective dopamine D4 receptor antagonist. Neuropharmacology 49:112–121PubMedCrossRefGoogle Scholar
- Osman S, Lundkvist C, Pike VW, Halldin C, McCarron JA, Swahn CG, Ginovart N, Luthra SK, Bench CJ, Grasby PM, Wikstrom H, Barf T, Cliffe IA, Fletcher A, Farde L (1996) Characterization of the radioactive metabolites of the 5-HT1A receptor radioligand, [O-methyl-11C]WAY-100635, in monkey and human plasma by HPLC: comparison of the behaviour of an identified radioactive metabolite with parent radioligand in monkey using PET. Nucl Med Biol 23:627–634PubMedCrossRefGoogle Scholar