Contributions of bile and pancreatic juice to cell proliferation in ileal mucosa.

To determine the relative contributions of bile and pancreatic juice to adaptive intestinal hyperplasia, cell proliferation in rat ileal mucosa was studied after supplying bile alone or the combined pancreaticobiliary effluent direct to mid-small bowel. Bile was routed through the choledochus cannulated above the pancreas. Pancreaticobiliary secretions were diverted through a transposed duodenal segment containing the papilla. Diversion of bile into the mid-bowel with and without pancreatic juice caused similar increases in ileal ribonucleic acid (RNA) (16% to 50%) and deoxyribonucleic acid (DNA) (22% to 41%) contents at both 48 hours and 1 week after operation. Specific activity of DNA after injection of tritiated thymidine was greatest after diversion of the combined effluent. After 1 month nucleic acid contents in the upper ileum after pancreaticobiliary diversion were 37% to 59% higher than after transection or biliary diversion (P less than 0.005). Likewise, after biliary diversion villous height and crypt depth were increased only at 1 week, but after diversion of both secretions increases were found at 1 week and 1 month. High luminal concentrations of bile cause transient cell proliferation in ileal mucosa, but the additional presence of pancreatic juice prolongs this adaptive response.