[Inhibitory effect of CR 1409 (cholecystokinin antagonist) on pancreatic exocrine secretion in rats].

New cholecystokinin (CCK) receptor antagonist, CR 1409 (lorglumide), was evaluated for anti-CCK activity on pancreatic exocrine secretion in anesthetized rats in vivo, compared with proglumide. Both CR 1409 in a dose range of 0.04-25 mg/kg-hr and proglumide in a dose range of 30-600 mg/kg-hr given intravenously, showed significant inhibitory effect on pancreatic secretion in terms of juice volume and amylase output stimulated by intravenous CCK-8 (0.06 micrograms/kg-hr), in a dose-related manner. CR 1409 is about 1000 times more potent than proglumide, based on ED 50. Furthermore, intravenous administration of either CR 1409 (5 mg/kg-hr) or proglumide (600 mg/kg-hr) resulted in significant suppression on pancreatic secretion stimulated by intraduodenal casein in a dose of 400 mg/hr. Thus, very potent CCK receptor antagonist, CR 1409, inhibited pancreatic exocrine secretion stimulated by not only exogenous CCK, but also intraduodenal casein in rats.