Contribution of bile and pancreatic juice to the control of pH in the pig duodenum.

To evaluate the respective contributions of biliary and pancreatic secretions in the formation of intraduodenal pH, 10 pigs were chronically fistulated in either the common bile duct (5 pigs) or the pancreatic duct (5 pigs). They were all fitted with a permanent catheter into the duodenum for the continuous return of secretion and with a duodenal T-cannula allowing the introduction of a combined glass electrode. pH was recorded over 8-hour periods in fed or fasted pigs in which both secretions were returned or in which either the bile or the pancreatic juice was not restituted. In fed pigs with secretions normally flowing into the duodenum, the pH fluctuated between 4 and 6 during 57% of the recording time; it exceeded 6 during 29% of this period. The rest of the time, it remained between 2 and 4. Bile deprivation did not change the duration of the 4 less than pH less than 6 and 2 less than pH less than 4 ranges, although a slight decrease of the pH greater than 6 time-course was recorded. Deprivation of pancreatic secretion did not induce significant variations of the pH pattern. In fasted pigs with restituted biliary and pancreatic secretions, a pH greater than 6 was recorded for 70% of the 8-hour period. The pH was lower in short periods: 19% (4 less than pH less than 6), 8% (2 less than pH less than 4) and less than 1% (pH less than 2) of the time.(ABSTRACT TRUNCATED AT 250 WORDS)