The effect of aripiprazole on prepulse inhibition of the startle response in normal and hyperdopaminergic states in rats.

This study compared the D(2) partial agonists, aripiprazole, (R(+)-terguride; S(-)-3-(3-hydroxyphenyl)-N-n-propylpiperidine [S(-)-3-PPP]; 7-[3-[4-(2,3-dimethylphenyl)piperazinyl]propoxy]-2(1H)-quinolinone [OPC-4392]) and D(2) antagonists (haloperidol, olanzapine, clozapine, risperidone, and quetiapine) on prepulse inhibition (PPI) of the startle response, and the ability to reverse apomorphine-induced deficits in the PPI response. Aripiprazole did not essentially affect PPI in naïve rats but dose-dependently restored apomorphine-induced PPI disruption. R(+)-terguride restored PPI disruption but suppressed PPI significantly in naïve rats, S(-)-3-PPP partially restored whereas OPC-4392 did not restore PPI disruption.

Differences in agonist/antagonist properties at human dopamine D(2) receptors between aripiprazole, bifeprunox and SDZ 208-912.

Aripiprazole is the first dopamine D(2) receptor partial agonist approved for use in schizophrenia and bipolar disorder. Other partial agonists have failed in various stages of development, either for reasons of poor tolerability or lack of efficacy. We conducted an in vitro comparative analysis between aripiprazole, bifeprunox, SDZ 208-912, OPC-4392 and ACR16 in attempt to correlate specific pharmacological properties with clinical outcome.

6-Hydroxybuspirone is a major active metabolite of buspirone: assessment of pharmacokinetics and 5-hydroxytryptamine1A receptor occupancy in rats.

The pharmacokinetics and in vivo potency of 6-hydroxybuspirone (6-OH-buspirone), a major metabolite of buspirone, were investigated. The plasma clearance (47.3 +/- 3.

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

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.

Aripiprazole's low intrinsic activities at human dopamine D2L and D2S receptors render it a unique antipsychotic.

Aripiprazole is the first clinically approved atypical antipsychotic agent having dopamine D2 receptor partial agonist activities. To evaluate aripiprazole's agonist and antagonist properties, we established a Chinese hamster ovary cell line expressing high and low densities of the long and short isoforms of human dopamine D2 receptors, then compared its properties with 7-{3-[4-(2,3-dimethylphenyl)piperazinyl]propoxy}-2(1H)-quinolinone (OPC-4392), S(-)-3-(3-hydroxyphenyl)-N-n-propylpiperidine ((-)-3-PPP), and terguride (other partial agonists) using forskolin-stimulated cAMP accumulation as an index. In cells expressing high receptor densities, all partial agonists predominantly behaved as agonists.

Ligand conformation has a definitive effect on 5-HT1A and serotonin reuptake affinity.

Conformationally constrained aryl cyclohexanes and cyclohexenes based on aryl cyclohexanols 1 were prepared. Locking the aryl ring in plane with the cyclohexane moiety provided potent SSRIs 3. Conversely, fixing the aryl ring perpendicular to the cyclohexane ring via a spiro lactone provided balanced 5-HT1A antagonists with mid-nanomolar range SSRI potency (compounds 2).

Diaminopyrimidine and diaminopyridine 5-HT7 ligands.

The present studies have identified a series of diaminopyrimidines and diaminopyridines as novel 5-HT(7) receptor ligands. Three regiosiomeric classes of pyrimidines and four regioisomeric classes of pyridines were synthesized and analyzed for binding to the 5-HT(7) receptor. The 5-HT(7) binding affinities of different regioisomers show clearly the structure-activity relationship with position of ring nitrogens.

Aminotriazine 5-HT7 antagonists.

The present studies have identified a series of aminotriazines as novel 5-HT(7) receptor antagonists. Compounds 10 and 17 have high affinity for the 5-HT(7) receptor and do not bind to either the 5-HT(2C) or 5-HT(6) receptors. These compounds produce no agonist effects by themselves, and shift the dose-response curve of 5-CT to the right in the manner of an antagonist.