A COMPARISON OF INTRAGASTRIC AND DUODENAL FACTORS IN LOWERING THE ACIDITY OF GASTRIC CONTENTS

Abstract

Studies before and after ligation of the bile and pancreatic ducts showed that following ligation, acid solns. placed in the stomach were reduced in acidity less rapidly and less completely than before ligation. Reduction in acidity became evident only when the volume of solution remaining in the stomach was very small. In isolated pyloric and duodenal pouches the alkalinity of the pyloric and duodenal secretions was about the same, ave. value approximately 0.04 normal. The chloride content of pyloric secretion averaged 376 mgm. per 100 cc, that of duodenal secretions 310 mgm. The ratio of neutral chloride to cc. of secretion averaged 52 in pyloric and 4.7 in duodenal secretions. A correction of these ratios reduced them to 4.1 and 3.7 respectively. The total amount of secretion by pyloric pouches when filled with N/10 HCl averaged 4 cc. for [image]-hr. periods and under certain conditions the amount could be raised to 9-14 cc. Duodenal pouches secreted larger amounts,[long dash]ave. for [image]-hr. periods being 19 cc. In exps. on the intact normal stomach filled with N/10 HCl and stimulated with histamine it was possible to separate the total fluid entering the stomach into 2 parts: (1) secreted HCl which was not neutralized; (2) the "extra fluid" which consists of neutralized HC1, pyloric secretions and regurgitated duodenal secretions. The ratio of the neutral chloride to the cc. of extra fluid averaged 4.4 in 68 exps. while the value in individual dogs was 4-5. These ratios are very similar to those obtained in pyloric and duodenal pouches and seem to justify the conclusion that the ratios in the whole stomach are similar in their significance to those in the pouches. In the whole stomach there was a direct relationship between the amount of extra fluid, neutral chloride, bile and acid deficit. These experiments show that it is a mistake to consider the entire neutral chloride fractions of gastric contents as arising from neutralized HCl. Both pyloric and duodenal secretions reduce acidity more by dilution than by neutralization, and the greater efficiency of regurgitated duodenal contents is due to the fact that more of it may be available.