A PACAP receptor agonist (IC50s = 3, 2, and 5 nM, respectively, for rat PAC1, rat VPAC1, and human VPAC2 recombinant receptors); binds to PACAP receptors in rat brain membrane (IC50 = 9.55 nM) and to SH-SY5Y and SK-N-MC human neuroblastoma and T47D human breast cancer cells (IC50s = 1.1, 1.9, and 0.9 nM, respectively); stimulates cAMP accumulation in H-SY5Y, SK-N-MC, and T47D cells (EC50s = 0.19, 0.22, and 0.17 nM, respectively); induces vasodilation of pial arterioles by 36% in newborn pigs (1 μM)