Animal experiment:

SD rats are individually isolated in clear plastic cages and injected with methamphetamine (MAP) (1 mg/kg i.p.) 1 h after the administration of drugs or vehicle. In the test of persistence of the effect, Lurasidone (SM-13496) is administered 1, 2, 4, and 8 h before the MAP injection. Locomotor activity is measured for 80 min from 10 min after MAP injection. Four or five groups of 6 to 13 rats are used to calculate the ED50 value that inhibits MAP-induced hyperactivity by 50% of the animals tested[1].

Lurasidone (SM-13496) is an antagonist of both dopamine D2 and 5-HT7 with IC50s of 1.68 and 0.495 nM, respectively. Lurasidone (SM-13496) is also a partial agonist of 5-HT1A receptor with an IC50 of 6.75 nM.

Lurasidone (SM-13496) is an antagonist of dopamine D2 and 5-HT7 with IC50s of 1.68±0.09 and 0.495±0.090 nM, respectively. Lurasidone (SM-13496) is also a partial agonist of 5-HT1A receptor with an IC50 of 6.75±0.97 nM. In vitro receptor binding experiments reveal that Lurasidone (SM-13496) demonstrates affinity for dopamine D2 and 5-HT2A receptors higher than other tested antipsychotics. Lurasidone (SM-13496) does not increase [35S]GTPγS binding to the membrane preparations for dopamine D2 receptors by itself, but it antagonizes dopamine-stimulated [35S]GTPγS binding in a concentration-dependent manner with a KB value of 2.8±1.1 nM[1].

Lurasidone (SM-13496) dose-dependently increases the ratio of DOPAC/dopamine in frontal cortex and striatum, but it shows a preferential effect on the frontal cortex compare with the striatum, especially at higher doses. Lurasidone (SM-13496) (ED50 values 2.3 to 5.0 mg/kg) shows a comparable potency with olanzapine (ED50 values 1.1 to 5.1 mg/kg), higher potency than clozapine (ED50 9.5 to 290 mg/kg), and slightly lower potency than haloperidol (ED50 values 0.44 to 1.7 mg/kg). Lurasidone (SM-13496) (1 to 10 mg/kg) dose-dependently inhibits conditioned avoidance response (CAR) in rats, and the ED50 values are 6.3 mg/kg. Lurasidone (SM-13496) dose-dependently inhibits tryptamine (TRY)-induced forepaw clonic seizure and p-chloroamphetamine (p-CAMP)-induced hyperthermia with ED50 values of 5.6 and 3.0 mg/kg, respectively. Lurasidone (SM-13496) (0.3 to 30 mg/kg) dose-dependently and significantly increases the number of shocks received by rats in the conflict test with MED of 10 mg/kg (p<0.01)[1].

[1]. Ishibashi T, et al. Pharmacological profile of lurasidone, a novel antipsychotic agent with potent 5-hydroxytryptamine 7 (5-HT7) and 5-HT1A receptor activity. J Pharmacol Exp Ther. 2010 Jul;334(1):171-81. [2]. Sakine Atila Karaca, et al. Development of a validated high-performance liquid chromatographic method for the determination of Lurasidone in pharmaceuticals. Marmara Pharm J. 2017;21 (4): 931-937.