text: The most potent compound, << D,L-4-(3,4-dichlorobenzoylamino)-5-(dipentylamino)-5-oxo-pen tanoic acid >> (lorglumide, CR 1409), has a great affinity for the pancreatic CCK receptors and is a competitive, specific and potent [[ CCK ]] antagonist on the smooth muscles of the gall bladder and ileum of the guinea pig and on the CCK-induced amylase secretion of isolated pancreatic acini.