TY - JOUR T1 - S33005, a Novel Ligand at Both Serotonin and Norepinephrine Transporters: I. Receptor Binding, Electrophysiological, and Neurochemical Profile in Comparison with Venlafaxine, Reboxetine, Citalopram, and Clomipramine JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 565 LP - 580 VL - 298 IS - 2 AU - Mark J. Millan AU - Alain Gobert AU - Françoise Lejeune AU - Adrian Newman-Tancredi AU - Jean-Michel Rivet AU - Agnès Auclair AU - Jean-Louis Peglion Y1 - 2001/08/01 UR - http://jpet.aspetjournals.org/content/298/2/565.abstract N2 - S33005 displayed marked affinity for native, rat, and cloned human serotonin (5-HT) transporters (SERT) and less pronounced affinity for norepinephrine (NE) transporters (NET), while its affinity at dopamine (DA) transporters and >50 other sites was negligible. Reuptake of 5-HT and (less potently) NE into cerebral synaptosomes was inhibited by S33005, whereas DA reuptake was little affected. In vivo, S33005 prevented depletion of cerebral pools of 5-HT by parachloroamphetamine. Furthermore, it decreased electrical activity of raphe-localized serotonergic neurones, an action abolished by the 5-HT1A antagonist WAY100,635. At higher doses, S33005 blocked firing of locus ceruleus-localized adrenergic neurones, an action abolished by the α2-adrenergic antagonist idazoxan. In contrast, S33005 did not inhibit ventrotegmental dopaminergic neurones. In frontal cortex of freely moving rats, S33005 dose dependently elevated dialysate levels of 5-HT, NE,and DA. In hippocampus, levels of 5-HT and NE were similarly elevated, while in nucleus accumbens and striatum, levels of 5-HT were increased whereas DA was unaffected. Upon chronic (2 weeks) administration, basal levels of NE were elevated in frontal cortex and, therein, 5-HT2A receptor density was decreased. Comparative studies with clinically used antidepressants showed that venlafaxine possessed a profile similar to S33005 but was less potent. Clomipramine likewise interacted with SERTs and NETs but also with several other receptors types, while citalopram and reboxetine were preferential ligands of SERTs and NETs, respectively. In conclusion, S33005 interacts potently with SERTs and, less markedly, with NETs. It enhances extracellular levels of 5-HT and NE throughout corticolimbic structures and selectively elevates dialysis levels of DA in frontal cortex versus subcortical regions. The American Society for Pharmacology and Experimental Therapeutics ER -