Composition of the Mixed Duodenal Secretions

Abstract

Summary

The average alkalinity of the duodenal secretions was found to be approximately .04 normal and the chloride concentration 307 mg. per 100 cc. These values obtained on secretions from the intact duodenum are in excellent agreement with values previously reported on secretion obtained from isolated duodenal pouches.

In a previous communication 1 the results of studies on the composition of mixed duodenal secretions were reported. These previous studies were performed on healed duodenal pouches completely isolated from the stomach and every effort was made to avoid all complications which might alter the composition of the mixed duodenal secretions. However, it appeared necessary to confirm these results by different methods which would be free of certain hypothetical sources of error, based primarily on the operative procedures previously employed. A large number of analyses of the contents of the dogs'stomach obtained by lavage 24 hours after a light feeding of milk and syrup have shown that under these conditions hydrochloric acid is either absent or present in very small amounts. It therefore seemed that duodenal contents obtained from the intact duodenum, 24 hours after a light feeding of milk and syrup, would be practically free from contamination by acid gastric contents. Gastrostomy openings were made low on the body of the stomach through which a duodenal tube was inserted and the tip allowed to pass into the duodenum. When the dogs were lying on the side, the main cavity of the stomach was usually below the opening into the duodenum. At frequent intervals during the experiments a small rubber catheter was passed into the stomach and an attempt made to aspirate gastric secretions. Nothing but a small amount of tenacious mucus was ever obtained. The duodenum was stimulated by introducing a standard hydrochloric acid solution (approximately one-tenth normal) containing phenol red through the duodenal tube. After a latent period of several minutes'duration a copious flow of duodenal secretions occurred. The secretions aspirated from the duodenum often contained some of the acid-phenol red solution which had been introduced but the phenol red was too dilute to determine accurately, hence the duodenal secretions were added to approximately 25 cc. of the same strength acid-phenol red solution that had been introduced into the duodenum.