Olivier Muller

S32006, a novel 5-HT2C receptor antagonist displaying broad-based antidepressant and anxiolytic properties in rodent models.

RationaleSerotonin (5-HT)2C receptors are implicated in the control of mood, and their blockade is of potential interest for the management of anxiodepressive states.ObjectivesHerein, we characterized the in vitro and in vivo pharmacological profile of the novel benzourea derivative, S32006.Materials and methodsStandard cellular, electrophysiological, neurochemical, and behavioral procedures were used.ResultsS32006 displayed high affinity for human (h)5-HT2C and h5-HT2B receptors (pKis, 8.4 and 8.0, respectively). By contrast, it had negligible (100-fold lower) affinity for h5-HT2A receptors and all other sites examined. In measures of Gq-protein coupling/phospholipase C activation, S32006 displayed potent antagonist properties at h5-HT2C receptors (pKB values, 8.8/8.2) and h5-HT2B receptors (7.8/7.7). In vivo, S32006 dose-dependently (2.5–40.0xa0mg/kg, i.p. and p.o.) abolished the induction of penile erections and a discriminative stimulus by the 5-HT2C receptor agonist, Ro60,0175, in rats. It elevated dialysis levels of noradrenaline and dopamine in the frontal cortex of freely moving rats, and accelerated the firing rate of ventrotegmental dopaminergic and locus ceruleus adrenergic neurons. At similar doses, S32006 decreased immobility in a forced-swim test in rats, reduced the motor depression elicited by 5-HT2C and α2-adrenoceptor agonists, and inhibited both aggressive and marble-burying behavior in mice. Supporting antidepressant properties, chronic (2–5xa0weeks) administration of S32006 suppressed “anhedonia” in a chronic mild stress procedure and increased both expression of BDNF and cell proliferation in rat dentate gyrus. Finally, S32006 (0.63–40xa0mg/kg, i.p. and p.o) displayed anxiolytic properties in Vogel conflict and social interaction tests in rats.ConclusionS32006 is a potent 5-HT2C receptor antagonist, and possesses antidepressant and anxiolytic properties in diverse rodent models.

Synthesis and biological evaluation of new tetrahydronaphthalene derivatives as thromboxane receptor antagonists.

New polysubstituted tetrahydronaphthalene derivatives were prepared as thromboxane receptor (TP-receptor) antagonists. Within this series of compounds S 18886 has been identified as an orally active, highly potent antagonist with a very long duration of action in different species.

Synthesis of new 3,4-disubstituted pyrrolidines as thromboxane A2/prostaglandin H2 (TP) receptor antagonists

Abstract The synthesis and TP-receptor antagonistic activity of a series of 3,4-disubstituted pyrrolidines is described. The sulfonamide 1h was the most potent TP-receptor antagonist in this series with a pA 2 value of 9.5 in isolated guinea pig trachea.

S32212, a Novel Serotonin Type 2C Receptor Inverse Agonist/α2-Adrenoceptor Antagonist and Potential Antidepressant: I. A Mechanistic Characterization

Although most antidepressants suppress serotonin (5-HT) and/or noradrenaline reuptake, blockade of 5-HT2C receptors and α2-adrenoceptors likewise enhances monoaminergic transmission. These sites are targeted by the urea derivative N- [4-methoxy-3-(4-methylpiperazin-1-yl)phenyl]-1,2-dihydro-3-H-benzo[e]indole-3-carboxamide (S32212). S32212 was devoid of affinity for monoamine reuptake sites, yet displayed pronounced affinity (pKi, 8.2) for constitutively active human 5-HT2CINI (h5-HT2CINI) receptors, behaving as an inverse agonist in reducing basal Gαq activation, [3H]inositol-phosphate production, and the spontaneous association of h5-HT2CINI-Renilla luciferase receptors with β-arrestin2-yellow fluorescent protein. Furthermore, upon 18-h pretreatment, S32212 enhanced the plasma membrane expression of h5-HT2CINI receptors as visualized by confocal microscopy and quantified by enzyme-linked immunosorbent assay. Its actions were prevented by the neutral antagonist 6-chloro-5-methyl-N-[6-(2-methylpyridin-3-yloxy)pyridin-3-yl]indoline-1-carboxamide (SB242,084), which also impeded the induction by long-term exposure to S32212 of otherwise absent Ca2+ mobilization in mouse cortical neurones. In vivo, S32212 blunted the inhibitory influence of the 5-HT2C agonist 2-(3-chlorobenzyloxy)-6-(1-piperazinyl)pyrazine (CP809,101) on ventrotegmental dopaminergic neurones. S32212 also blocked 5-HT-induced Gαq and phospholipase C activation at the h5-HT2A and, less potently, h5-HT2B receptors and suppressed the discriminative stimulus properties of the 5-HT2A agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane in rats. S32212 manifested marked affinity for human α2A- (pKi 7.2), α2B- (pKi 8.2), and α2C- (pKi 7.4) adrenoceptors, at which it abolished noradrenaline-induced recruitment of Gαi3, Gαo, adenylyl cyclase, and extracellular-regulated kinase1/2. Moreover, S32212 dose-dependently abolished the discriminative stimulus effects of the α2-adrenoceptor agonist (S)-spiro[(1-oxa-2-amino-3-azacyclopent-2-ene)-4,2′-(1′,2′,3′,4′-tetrahydronaphthalene)] (S18616). Finally, S32212 displayed negligible affinity for α1A-adrenoceptors, histamine H1 receptors, and muscarinic M1 receptors. In conclusion, S32212 behaves as an inverse agonist at h5-HT2C receptors and as an antagonist at human α2-adrenoceptors (and h5-HT2A receptors). Its promising profile in preclinical models potentially relevant to the treatment of depression is described in J Pharmacol Exp Ther 340:765–780, 2012.