STUDIES ON THE CONTROL OF THE ACIDITY OF THE GASTRIC JUICE

Abstract

The author devised a method for doing fractional gastric analysis on the normal dog. Histamine and a test-meal of meat and water were used to stimulate the secretion of acid. The uniformity of the results gave value to the method. In the 1st stages, 7 dogs underwent surgical duodenal drainage whereby all the duodenal alkalis were shunted away from the pylorus into the distal portion of the ileum. Post-operative fractional analysis did not show variations from the curves found before operation so far as they represented the chemistry of digestion, or the control of the acidity of the juice. The addition of carbohydrate and fat to the protein meal showed the same alterations of the curves from a meal of meat and water in normal dogs and in operated dogs. The final control of the acid was not altered. Regurgitation of the duodenal alkalis is not, therefore, the essential mechanism for controlling the acidity of the gastric juice, but is probably an associated phenomenon. The results showed that after the acid has stopped combining with the food, the mechanism for controlling the acidity of the juice consists probably of 2 factors capable of bringing the juice to complete neutralization (1) a gradual reduction of an established high rate of secretion of the acid to a low rate; (2) the capacity of the constant basal secretion of mucus to combine with a constant fraction of the changing volume of acid secreted. This mucus is probably derived from the adjacent mucus-secreting glands in the fundus. When the rate of secretion of acid has fallen to the low basal rate of the resting stomach, the amt. secreted apparently is so small that it completely combines with the basal mucous secretion, giving a combined acid and a neutral (base) chloride.