SB 222200 is a selective and potent antagonist of NK-3 receptor [1].
Neurokinin-3 (NK-3) receptor is a member of the G-protein-coupled superfamily and functions as a receptor for tachykinin. Activation of NK-3 receptors causes phosphoinositol 4, 5 biphosphate
(PIP2) breakdown into 1,4,5 inositol triphosphate (IP3) and diacylglycerol through phospholipase C activation [1].
In Chinese hamster ovary (CHO) cell expressing the hNK-3 receptor, SB 222200 inhibited neurokinin B (NKB) binding to the cell membranes with a Ki value of 4.4 nM. In HEK 293 cells expressing the hNK-3 receptor, SB 222200 antagonized NKB-induced Ca2+ mobilization with an IC50 value of 18.4 nM [1].
In mice model, SB-222200 inhibited behavioral responses (rapid head shakes and tail whips) induced by senktide (the NK-3 receptor-selective agonist) with an ED50 value of 5 mg/kg in a dose-dependent way and the inhibitory effect correlated significantly with brain concentrations of SB-222200 [1]. Treatment adult male CD-1 mice with SB 222200, mice had significantly enhanced hyperactivity when challenged with cocaine, which suggested that blockade of NK-3 receptors enhanced dopamine-mediated behavioral hyperactivity.
References:
[1]. Sarau HM, Griswold DE, Bush B, et al. Nonpeptide tachykinin receptor antagonists. II. Pharmacological and pharmacokinetic profile of SB-222200, a central nervous system penetrant, potent and selective NK-3 receptor antagonist. J Pharmacol Exp Ther, 2000, 295(1): 373-381.
[2]. Nwaneshiudu CA, Unterwald EM. Blockade of neurokinin-3 receptors modulates dopamine-mediated behavioral hyperactivity. Neuropharmacology, 2009, 57(3): 295-301.