This experimental study on dogs was undertaken to measure the pH of duodenal contents before and after experimental procedures designed to prevent pancreatic secretions from entering the gastrointestinal tract. One procedure caused loss of all juice through an external fistula. Another caused atrophy of all acinar tissue. The third was total removal of the pancreas.
The question which this study attempted to answer was: Does it make any difference with regard to duodenal pH whether pancreatic juice is secreted but lost or not secreted at all?
We felt that the most physiologic way to measure differences, if any, after the 3 experimental surgical procedures was to make continuous in situ recordings of the pH of a localized region of the duodenum during fasting and then for 18 to 24 hours after feeding. The technique used was that of Humphreys and associates. A Mann-Bollman fistula was first established in each
HARTZELL JM, GRINDLAY JH, PRIESTLEY JT, BOLLMAN JL. Changes in Duodenal pH After Exclusion of Pancreatic Secretions in Dogs. Arch Surg. 1962;85(1):142-151. doi:10.1001/archsurg.1962.01310010146020