Benzquinamide

Benzquinamide (P2647; BZQ; Benzoquinamide) is an orally active binder of dopamine receptors and adrenergic receptors. Benzquinamide specifically targets dopamine D2, D3, D4 receptors and α-2A, α-2B, α-2C adrenergic receptors. Benzquinamide regulates blood pressure and heart rate, attenuates the pressor effect of adrenaline, and exhibits activities such as antiemesis, anxiolysis, and reduction of histamine-induced bronchoconstriction. Benzquinamide has good safety and does not deplete serotonin or norepinephrine in the brain. Benzquinamide can be used in studies related to nausea/vomiting, mental disorders, anxiety states, neurosis, and psychosis^[1][2]. IC50 & Target:K_i: 1,365 nM (α_2A), 691 nM (α_2B), 545 nM (α_2C)^[1]. In Vitro:Benzquinamide binds to human dopamine D₂, D₃, and D₄ receptors, with the highest affinity for the D₄ subtype (K_i=574 nM)^[1].
Benzquinamide (10 μM) binds to human α_2A, α_2B, and α_2C adrenergic receptors, with the highest affinity for the α_2C subtype (K_i=545 nM), and does not produce meaningful binding to histamine H1 receptors or muscarinic M1-M5 receptors^[1]. In Vivo:Benzquinamide (16.5 mg/kg; i.p.) specifically disrupts conditioned avoidance behavior in rats with an ED₅₀ of 16.5 mg/kg (i.p.), with 3.7-fold greater potency for disrupting avoidance than escape behavior^[2].
Benzquinamide (5-20 mg/kg; i.p.) inhibits isolation-induced fighting behavior in male mice starting at 5 mg/kg (i.p.) without causing muscle relaxation or impaired coordination^[2].
Benzquinamide (0.4-1.6 mg/kg; i.v.; 4.0-6.0 mg/kg; p.o.) blocks apomorphine-induced emesis in dogs with an intravenous ED₅₀ of approximately 0.9 mg/kg, and fully blocks emesis at 6.0 mg/kg (p.o.)^[2].
Benzquinamide (10-25 mg/kg; i.v.) does not deplete brain serotonin or norepinephrine concentrations in dogs at doses up to 25 mg/kg (i.v.)^[2].
Benzquinamide (10 mg/kg; i.v.) does not exhibit neuromuscular activity in Felis catus at 10 mg/kg (i.v.)^[2].