S 14506 is an agonist of the serotonin (5-HT) receptor subtype 5-HT1A.1,2,3,4 It selectively binds 5-HT1A over 5-HT1B, 5-HT1C, 5-HT2, and 5-HT3 receptors (Kis = 0.98, 281.8, 31.6, 229, and >1,000 nM, respectively) but also binds the dopamine D2 receptor (Ki = 4.57 nM) in radioligand binding assays.1,2 S 14506 stimulates GTPase activity in HEK293 cell membranes expressing 5-HT1A-Gαi1 or 5-HT1A-Gαo1 fusion proteins in a concentration-dependent manner.3 It reduces immobility time in the forced swim test in rats with a minimum effective dose (MED) of 0.01 mg/kg.4 S 14506 (0.0025-0.63 mg/kg) increases punished responding in a pigeon conflict procedure, indicating anxiolytic-like activity.1
1.Colpaert, F.C., Koek, W., Lehmann, J., et al.S 14506: A novel, potent, high-efficacy 5-HT1A agonist and potential anxiolytic agentDrug Dev. Res.26(1)21-48(1992) 2.Protais, P., Chagraoui, A., Arbaoui, J., et al.Dopamine receptor antagonist properties of S 14506, 8-OH-DPAT, raclopride and clozapine in rodentsEur. J. Pharmacol.271(1)167-177(1994) 3.Milligan, G., Kellett, E., Dacquet, C., et al.S 14506: Novel receptor coupling at 5-HT1A receptorsNeuropharmacology40(3)334-344(2000) 4.Schreiber, R., Brocco, M., Gobert, A., et al.The potent activity of the 5-HT1A receptor agonists, S 14506 and S 14671, in the rat forced swim test is blocked by novel 5-HT1A receptor antagonistsEur. J. Pharmacol.271(2-3)537-541(1994)