In vitroactivity: PD 128907 HCl is a potent and selective dopamine D3 receptor agonist, with EC50 of 0.64 nM, exhibits 53-fold selectivity over dopamine D2 receptor. When using [3H]spiperone as the radioligand in CHOKl-cells, PD 128907 exhibits about a l000-fold selectivity for human D3 receptors (Ki, 1 nM) versus human D2 receptors (Ki, 1183 nM) and a l0000-fold selectivity versus human D4receptors (Ki, 7000 nM). PD 128907 is used for studying the role of these receptors in the brain, in roles such as inhibitory autoreceptors that act to limit further dopamine release.

Kinase Assay: (+)-PD 128907 hydrochloride is a selective dopamine D2/D3 receptor agonist, with Kis of 1.7, 0.84 nM for human and rat D3 receptors, 179, 770 n M for human and rat D3 receptors, respectively.