PROLIFERATIVE RESPONSE OF DIFFERENT EXOCRINE PANCREATIC-CELLS AFTER SURGICAL PANCREATICOBILIARY DIVERSION IN THE RAT

Pancreaticobiliary diversion (PBD) is known to induce chronic, endogenous hypercholecystokininemia causing pancreatic growth in rats. In the present study the proliferative response of the different exocrine pancreatic cells was studied by administration of H-3-thymidine, 1 mCi/kg, given 1 h before the rats were killed and 5, 10, 20, and 40 days after PBD. DNA and H-3-thymidine uptake, both expressed per 1 mg of pancreatic tissue, were significantly increased on day 5. The nuclear labeling index was increased fivefold in both the acinar and ductal cell groups on day 5 and was significantly increased also on day 10 in the acinar cell group. In the centroacinar cell group the labeling index was increased on day 10. In conclusion, we found that the proliferative activity after PBD occurred during the first 10 days and that the ductal cells were forced into proliferation to the same extent as the acinar ones. These findings are of interest for future studies of hormonal influences on the development of pancreatic carcinoma.