Exocrine pancreatic nodules after longterm pancreaticobiliary diversion in rats. An effect of raised CCK plasma concentrations.

Abstract

Surgical diversion of bile and pancreatic secretions to the mid small bowel has been shown to provoke increased CCK plasma concentration and growth of the pancreas in rats. This study was undertaken to investigate the effects of chronic pancreaticobiliary diversion on pancreatic morphology as well as the circulating concentrations of pancreatic polypeptide, secretin, gastrin, and CCK. Fifteen month diversion provoked 73 and 86% increases in pancreatic weight and volume (p less than 0.001). Cholecystokinin blood concentration increased by 98%, from 20.9 +/- 5.7 pg/ml in controls to 41.3 +/- 5.4 after diversion (p less than 0.05), but pancreatic polypeptide, secretin, and gastrin levels were not affected. The volume of the exocrine pancreas doubled from 1104.6 +/- 78.2 mm3 in controls to 2201.2 +/- 229.2 (p less than 0.001), with a matching increase in interstitial tissue. On the contrary, the volume of the endocrine pancreas remained unchanged. Hyperplastic nodules developed in the exocrine pancreas, in 71% of diverted rats, but not in transected controls. We conclude from these observations that chronic diversion of bile and pancreatic juice stimulated pancreatic growth, most likely through a persistent rise of CCK plasma concentrations. Furthermore, this long lasting stimulation induced the development of exocrine pancreatic nodules.