PD 168077 is a dopamine D4 receptor agonist (Ki = 8.7 nM in CHO Pro 5 cells expressing the human receptor). It is selective for dopamine D4 over D2 and D3 receptors (Kis = 3,740 and 2,810 nM, respectively), as well as α1- and α2-adrenergic and serotonin (5-HT) receptor subtypes 5-HT1A and 5-HT2A (Kis = 168, 177, 385, and 4,010 nM, respectively). PD 168077 (20 μM) induces CaMKII translocation from the dendritic shaft to postsynaptic sites on the dendritic processes of primary rat embryonic prefrontal cortex pyramidal neurons, an effect that can be blocked by the IP3 receptor antagonist 2APB or the calcium chelator BAPTA AM . PD 168077 (50-200 ng/animal) induces penile erections in rats when injected into the paraventricular nucleus (PVN) of the hypothalamus. PD 168077 (0.2-25 mg/kg, s.c.) increases spontaneous locomotor activity and reduces grooming and rearing in rats.
