Interaction of the novel antipsychotic aripiprazole with 5-HT1A and 5-HT 2A receptors: functional receptor-binding and in vivo electrophysiological studies.

Article Details

Citation

Stark AD, Jordan S, Allers KA, Bertekap RL, Chen R, Mistry Kannan T, Molski TF, Yocca FD, Sharp T, Kikuchi T, Burris KD

Interaction of the novel antipsychotic aripiprazole with 5-HT1A and 5-HT 2A receptors: functional receptor-binding and in vivo electrophysiological studies.

Psychopharmacology (Berl). 2007 Feb;190(3):373-82. Epub 2006 Nov 25.

PubMed ID
17242925 [ View in PubMed
]
Abstract

BACKGROUND: Aripiprazole (7-{4-[4-(2,3-dichlorophenyl)-1-piperazinyl]butoxy}-3,4-dihydro-2(1H)-quinolinone ) is a novel antipsychotic with a mechanism of action that differs from current typical and atypical antipsychotics. Aripiprazole interacts with a range of receptors, including serotonin [5-hydroxytryptamine (5-HT)] and dopamine receptors. MATERIALS AND METHODS: This study examined aripiprazole's interactions with 5-HT systems in vitro and in vivo to further clarify its pharmacologic properties. RESULTS: Aripiprazole produced increases in [(35)S]GTPgammaS binding to rat hippocampal membranes. Its potency (pEC(50) = 7.2) was similar to that of ziprasidone (7.1) and greater than that of 5-HT (6.7) and buspirone (6.4), a 5-HT(1A)-receptor partial agonist, whereas its intrinsic activity was similar to that of ziprasidone and buspirone. The stimulatory effect of aripiprazole was blocked by WAY-100635, a 5-HT(1A)-receptor antagonist. In in vivo electrophysiology studies, aripiprazole produced a dose-related reduction in the firing rate of 5-HT-containing dorsal raphe neurons in rats, which was both prevented and reversed by WAY-100635 administration. Aripiprazole showed a high affinity for human 5-HT(1A) receptors (K (i) = 4.2 nM) using parietal cortex membrane preparations. In membranes from cells expressing human recombinant receptors, aripiprazole bound with high affinity to 5-HT(2A) receptors (K (i) = 3.4 nM), moderate affinity to 5-HT(2C) (K (i) = 15 nM) and 5-HT(7) (K (i) = 39 nM) receptors, and low affinity to 5-HT(6) receptors (K (i) = 214 nM) and 5-HT transporter (K (i) = 98 nM). In addition, aripiprazole potently blocked 5-HT(2A)-receptor-mediated increases in intracellular Ca(2+) levels in a rat pituitary cell line (IC(50) = 11 nM). DISCUSSION: These results support a partial agonist activity for aripiprazole at 5-HT(1A) receptors in vitro and in vivo, and suggest important interactions with other 5-HT-receptor subtypes. This receptor activity profile may contribute to the antipsychotic activity of aripiprazole in humans.

DrugBank Data that Cites this Article

Drug Targets
DrugTargetKindOrganismPharmacological ActionActions
Aripiprazole5-hydroxytryptamine receptor 2AProteinHumans
Yes
Antagonist
Details
Aripiprazole lauroxil5-hydroxytryptamine receptor 2AProteinHumans
Yes
Antagonist
Details