Dopamine D1 and D2 receptor selectivities of agonists and antagonists

The selectivities of various dopamine agonists and antagonists for dopamine D1 and D2 receptors were obtained by comparing their relative dissociation constants for inhibiting the binding of [3H]SCH 23390 at D1 receptors (calf caudate nucleus) and at D2 receptors (pig anterior pituitary tissue). The most selective agonists were SK&F 38393 (for D1) and (+)-PHNO (for D2), while the most selective antagonists were SCH 23390 (for D1) and raclopride or eticlopride (for D2).