A PACAP receptor antagonist (IC50s = 1,500, 600, and 300 nM, respectively, for rat PAC1, rat VPAC1, and human VPAC2 recombinant receptors); binds to PACAP receptors on SH-SY5Y and SK-N-MC human neuroblastoma and T47D human breast cancer cells (IC50s = 24.5, 106, and 105 nM, respectively); inhibits PACAP (1-38)-stimulated cAMP accumulation in SH-SY5Y, SK-N-MC, and T47D cells (Kis = 457, 102, and 283 nM, respectively); inhibits vasodilation of pial arterioles induced by PACAP (1-27) and PACAP (1-38) in newborn pigs (10 μM); inhibits PACAP (1-27)-stimulated increases in plasma insulin and glucagon levels and pancreatic venous blood flow in dogs (500 μg administered locally to the pancreas),