Amelioration of cholinergic-induced pancreatitis with a selective cholecystokinin receptor antagonist. Acute edematous pancreatitis follows excessive cholinergic stimulation in patients exposed to anticholinesterase-containing insecticides. We describe the role of cholecystokinin and the benefits of cholecystokinin receptor blockade in this form of pancreatitis. A cholinergic mimetic (carbachol) was administered to rats weighing 300 to 350 g and produced a form of edematous pancreatitis that mimics that seen in humans. Animals received carbachol intraperitoneally, either alone (250 micrograms/kg of body weight) or with cholecystokinin-receptor antagonist devazepide (3 mg/kg of body weight) and were killed 4 hours later. Carbachol administration resulted in a 19% increase in pancreatic weight, a fourfold increase in serum amylase levels, and a 14-fold increase in serum lipase levels. Plasma cholecystokinin levels, however, were not altered. Devazepide administered prior to cholinergic hyperstimulation blocked pancreatic weight increase and reduced elevations in serum amylase levels twofold and lipase levels fourfold. Although cholecystokinin levels are not elevated in this model of pancreatitis, blockade of even low, background concentrations of this regulatory peptide is beneficial. 