ESSENTIAL ROLE OF CHOLECYSTOKININ IN PANCREATIC REGENERATION AFTER 60-PERCENT DISTAL RESECTION IN RATS

The essential role of cholecystokinin (CCK) in pancreatic regeneration after pancreatitis or resection has been supposed, but not yet clearly demonstrated. In rats, 6-8 weeks after 60% distal resection of the pancreas a gradual increase in pancreatic weight and contents of DNA, protein, trypsin, chymotrypsin and amylase, occurred (there was no increase in lipase); Pancreatic regeneration stopped thereafter. Nonparallel increases in enzyme values were similar to those seen after CCK administration. Indeed, basal CCK levels increased significantly by the 6th week and declined thereafter. A one month s.c. administration of CCK-octapeptide (CCK-8) (3 x 300 ng/kg/d) accelerated regeneration in the first month, but it had almost no effect during the second or third postoperative months. A two week s.c. administration of a specific CCK antagonist, CR 1409 (3 x 4 mg/kg/d) totally prevented regeneration by the fifth and sixth weeks, but did not diminish pancreatic weight or DNA and protein contents during the first two weeks. Alcohol administration (12 g/kg/d) reduced CCK release and prevented pancreatic regeneration during the three-month experimental period. These data indicate that CCK has an essential role in pancreatic regeneration and that the deleterious effect of alcohol on regeneration involves inhibition of CCK release.