CHOLINERGIC DEPENDENCE OF PANCREATIC RESPONSE TO CHOLECYSTOKININ IN RATS AND GUINEA-PIGS

1. Lorglumide and atropine were used to examine the role of cholinergi c mechanisms in the pancreatic secretory response to cholecystokinin i n two animal species. 2. Anaesthetized rats and guinea pigs with jugul ar vein and pancreatic cannulae were used and the bile juice was recir culated. In the rat, the treatment with lorglumide (3 mu mol/kg) as we ll as atropine (100 mu g/kg) did not have effects on basal interdigest ive secretion, whereas in guinea pigs only atropine decreased the prot ein output (41%) and the juice flow (47%) of the basal pancreatic secr etion. 3. Infusion of cholecystokinin (150 pmol/kg/hr in the rat and 5 0 pmol/kg/hr in the guinea pig) induced a marked increase in pancreati c juice flow and protein output compared to saline controls. Pretreatm ent of both rat and guinea pig with lorglumide resulted in a marked at tenuation of the cholecysto kinin-evoked secretory response. 4. In the rats, atropine decreased the response to infusion of cholecystokinin octapeptide while this antimuscarinic agent had no effect in the respo nse to cholecystokinin in the guinea pigs. 5. This study supports the concept that the influence of cholinergic system in pancreatic respons e to cholecystokinin shows interspecific differences.