Preferential inhibition of ligand binding to calf striatal dopamine D1 receptors by SCH 23390.

The phenylbenzazepine derivative, SCH 23390 was found to be a potent inhibitor of 3H-piflutixol binding to calf striatal dopamine D1 receptors. In contrast SCH 23390 was only a weak inhibitor of 3H-spiperone binding to dopamine D2 receptors. Although possessing some activity at serotonin S2 and alpha 2 adrenergic receptors, SCH 23390 appears to be a potent and selective D1 receptor antagonist.