Nad-299 antagonises 5-HT-stimulated and spiperone-inhibited [35S]GTPgammaS binding in cloned 5-HT1A receptors.
In Chinese Hamster Ovary (CHO) cells expressing cloned human 5-hydroxytryptamine1A A (5-HT1A) receptors, (R)-3-N,N-dicyclobutylamino-8-fluoro-[6-3H]-3,4-dihydro-2H-1-benzopyan-5-carboxamide ([3H]NAD-299) exhibited high affinity (Kd = 0.16 nM) and labeled 34% more receptors than 8-hydroxy-2-([2,3-3H]di-n-propylamino)tetralin ([3H]8-OH-DPAT). NAD-299 behaved as a silent antagonist in [35S]GTPgammaS binding similar to N-tert-butyl-3-(4-(2-methoxyphenyl)-piperazin-1-yl)-2-phenylpropanamide (WAY-100635) and (S)-5-fluoro-8-hydroxy-2-(di-n-propylamino)tetralin ((S)UH-301). 5-HT and 5-carboxamidotryptamine (5-CT) stimulated [35S]GTPgammaS binding 2.5-fold while spiperone and methiothepin inhibited [35S]GTPgammaS binding 1.4-fold. Furthermore, NAD-299 antagonised both the 5-HT stimulated and the spiperone inhibited [35S]GTPgammaS binding to basal levels. The KiL/KiH ratios for spiperone (0.66), methiothepin (0.39), WAY-100635 (0.32), (S)UH-301 (0.94), NAD-299 (1.29), NAN-190 (1.23), (S)pindolol (5.85), ipsapirone (13.1), buspirone (24.6), (+/-)8-OH-DPAT (47.3), flesinoxan (55.8), 5-HT (200) and 5-CT (389) correlated highly significantly with the intrinsic activity obtained with [35S] GTPgammaS (r = 0.97).
Jerning
Eva
E
Department of Lead Discovery, AstraZeneca R&D Södertälje, Novum, Hälsovägen 7, S-141 57 Huddinge, Sweden. eva.jerning@astrazeneca.com
Rosqvist
Susanne
S
Mohell
Nina
N
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001578:Benzopyrans / Q000494:pharmacology*; D001667:Binding, Competitive; D016466:CHO Cells; D006224:Cricetinae; D018492:Dopamine Antagonists / Q000494:pharmacology*; D019204:GTP-Binding Proteins / Q000378:metabolism; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism*; D006801:Humans; D008719:Methiothepin / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D011869:Radioligand Assay; D011985:Receptors, Serotonin / Q000378:metabolism*; D044263:Receptors, Serotonin, 5-HT1; D012701:Serotonin / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology*; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D013134:Spiperone / Q000494:pharmacology*
D001578:Benzopyrans; D018492:Dopamine Antagonists; D010879:Piperazines; D011725:Pyridines; D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; C064282:UH 301; D012701:Serotonin; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D013134:Spiperone; D008719:Methiothepin; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D019204:GTP-Binding Proteins; C108607:robalzotan