Pancreatic juice contains fixed base at approximately the concentration found in the blood plasma. Chloride ion is present in concentrations varying from one-fourth to one-half the fixed base value and the remainder of the acid equivalence is composed of bicarbonate ion. Fixed base being a nearly stationary factor, variation of bicarbonate and thereby of alkalinity is referable to change in the concentration of chloride ion.
In bile, as delivered by the liver, both the fixed base and chloride ion values correspond closely with their respective concentrations in blood plasma. In gall bladder bile, however, the concentration of fixed base is, roughly, double that in hepatic duct bile, and chloride ion has been almost entirely removed.
From these data it may be inferred that loss of digestive secretions entering the duodenum will, in the absence of replacement of the materials contained, cause dehydration of the blood plasma and reduction of the plasma bicarbonate.