Table 1. Affinities (K_i) at Dopamine D₂ and D₃ Receptors^b.

^aSource and radioligands: D₁, rat striatum [³H]SCH23390; D₂, rat striatum [³H] domperidone; D₃, human D₃ clone [³H]domperidone; errors are expressed as standard deviations.

^bCompounds have been tested and found to have low affinity to D₁ (K_i > 5000) except for the following: 1 (K_i = 650 ± 310 nM), 2a (K_i = 490 ± 220 nM), 3b (K_i = 4300 ± 250 nM), 8f (K_i = 3700 ± 1200 nM), and 11e (K_i = 340 ± 44 nM), and no affinity to D₁^high, except for the following: 1 (K_i = 4.6 ± 1.2 nM), 2a (K_i = 1 ± 0.2 nM), and 2b (K_i = 8.1 ± 0.7nM); data for 1 and 2a obtained from ref (13).

^cCalculated using the chemical properties feature in CambridgeSoft ChemDraw Ultra, version 12.0.

^dData from ref (13).

^eData from ref (14).

^fFor preparation, see ref (40).

^gSee ref (25); HEK293T cell homogenate used with [³H]methylspiperone.

^hThe following compounds were also found to have D₃^high affinity: 2c (K_i = 3.8 ± 2 nM), 3a (K_i = 130 ± 100 nM), 3b (K_i = 1.2 ± 1 nM), 8a (K_i = 1.1 ± 2 nM), 8b (K_i = 1.9 ± 1.5 nM), 8c (K_i = 230 ± 140 nM), and 8d (K_i = 250 ± 19 nM).

ⁱSource and radioligands: D₃ rat clone [³H] domperidone; data provided by PDSP.