A-57696 is a cholecystokinin antagonist. It is selective for cortical CCK-B receptors (IC50 = 25 nM), compared with pancreatic CCK-A receptors (IC50 = 15 microM). It is a competitive antagonist in reversing CCK8-stimulated pancreatic amylase secretion and phosphoinositide breakdown. A-57696 behaved as a partial agonist in stimulating calcium mobilization at CCK-B/gastrin receptors.
