Relation between bicarbonate concentration and rate of canine pancreatic secretion

¹ Gastrointestinal Physiology Research Laboratory, The Mount Sinai Hospital, New York City

Most investigators have reported that the mathematical relation between [HCO₃] and volume-rate (V) in canine pancreatic secretion under various conditions is represented by plateau curves with [HCO₃] asymptotes, but with shapes and parameters which differ widely. Analysis of the present data, regardless of stimulus and dog, reveals similar curves with plateau values of 145 mEq/ liter, extending from about 0.7 to 2.1 ml/min. This graph was unaffected by adjustment of V for body weight. A breakdown according to stimulus yielded three regression lines with different parameters. Several operational factors are described to aid in attaining curves of uniform pattern hereafter. The fact has been ignored that each sample collected comprises some fluid retained in the collecting system from the preceding period, as well as some secreted during the collection period. Consequently, we must recognize the difference between rate of secretion and composition of the juice at its cellular source, and rate of collection and composition at the distal end of the duct. Errors from this source may contribute materially to the irregularity among the curves reported.

Key Words: pancreatic secretion, secretin stimulation • pancreatic secretion, histamine stimulation • pancreatic secretion, volume-rate of flow

Submitted on October 16, 1964