Mechanism of Gastric Secretion. The Nature of Gastric Juice of Constant Maximum Acidity.

Abstract

In a recent paper,1 it was reported that, by a modification of the usual technic for collecting gastric juice from a dog's auxiliary stomach pouch, a fluid of constant acidity was obtained. Independently of whether the secretory stimulus was food or histamine, the pH of the pouch juice had a constant value of 0.90±D0.01. The difference (a decrease of 0.02 pH) between this and the value originally reported may be due to individual variation as well as to improved technic. With further modifications in the latter, the maximum acidity may be found to be even slightly higher.Subsequent to the above report, the acid values of some representative samples were determined by titration. The micro-method employed involved titration to a definite end point with the aid of comparator tubes of known pH. For total acidity, phenol red at pH 7.8 was used; for free acidity, brom-phenol blue at 3.5. Also, in the case of a few of these samples, total chlorine was determined by the micro-method of Van Slyke.2 From the data s...