BP 897 (hydrochloride)

BP 897 hydrochloride is a potent and partial dopamine D3 receptor agonist and a weak D2 receptor antagonist. BP 897 hydrochloride displays a high affinity at the dopamine D3 receptor (K_i=0.92 nM) and a 70 times lower affinity at the D2 receptor (K_i=61 nM). BP 897 exhibits selective inhibition of cocaine-seeking behavior^[1]. IC50 & Target: Ki: 0.92 nM (D3 receptor), 61 nM (D2 receptor), 0.3 µM (D4 receptor), 3 µM (D1 receptor)^[1]. In Vitro: BP 897 hydrochloride also displays low affinities at D1 and D4 receptors (K_i=3 and 0.3 μM, respectively), as well as at α1 and α2 adrenergic receptors (K_i=60 and 83 nM, respectively), 5HT1A and 5HT7 receptors (K_i=84 and 345 nM, respectively), and negligible affinities (K_i>1 μM) atmuscarinic, histamine and opiate receptors^[1].
In NG 108-15 cells expressing the human D3 receptor, BP 897 hydrochloride inhibits forskolin-induced cyclic AMP accumulation with an EC₅₀ of 1 nM. BP 897 hydrochloride activates mitogenesis and this response is antagonized by the preferential D3 receptor antagonist Nafadotride (1 μM). BP 897 hydrochloride also partially antagonized the response induced by quinpirole (10 nM)^[1]. In Vivo: BP 897 hydrochloride binds to D2-receptor in mouse striatum with an ED₅₀ of 15 mg/kg, and the D3-receptor occupancy is blow 0.5 mg/kg. BP 897 (0.05, 0.5, 1 mg/kg; i.p.; 30 min before the session) hydrochloride reduces cocaine-seeking behaviour before the first infusion of cocaine, in a dose-dependent manner, at doses similar to those at which BP 897 hydrochloride produced its responses on rotations and c-fos expression^[1].