The ammonia of the fresh gastric juice was determined by a combination of Folin's aeration and the Nessler colorimetric methods, using 1 to 5 c.c. of the juice. The ammonia cannot be determined by the Nessler reagent directly in pure gastric juice, as parallel tests on the same samples of gastric juice yield higher figures by aeration and Nessler than by Nessler direct (using 1 c.c. of the juice).
Ammonia in the amounts of 2 to 3 gm. per 100 c.c. is a constant constituent of pure gastric juice of man and dog. The ammonia appears to be slightly more concentrated in the continuous secretion or hunger juice than in the appetite juice. The ammonia may be greatly increased in gastric ulcers, and in certain normal persons the ammonia may also be exceptionally high (10 to 15 mgr.).
Rosenheim and Strauss reported small amounts of ammonia in the gastric content of man. Zunz, working with the gastric content (test meals) on normal persons and on persons with various disorders of the alimentary tract, also reports the presence of ammonia. In the normal individuals the ammonia of the test-meal contents varied from 0.7 to 5.0 mgr. per 100 c.c. In cancers of the stomach the ammonia in the test-meal content was increased. The test meal introduces factors (bacterial action, saliva, etc.) not present in pure gastric juice. Sommerfeld, working with pure gastric juice of a ten-year-old girl with complete stricture of the esophagus, states that gastric juice contains no ammonia. Nencki, Zaleski, and Salaskin reported 4 to 5.5 mgr. ammonia per 100 c.c. pure gastric juice of the dog. Rosemann reports the constant presence of a small amount of ammonia in the pure gastric juice (appetite secretion) in the dog. Reisner concludes that the ammonia in gastric juice comes from the saliva.
What is the origin and significance of the gastric-juice ammonia ? It is known that saliva contains traces of ammonia. We find that the mixed saliva of man contains from 0.5 to 1.5 mgr. ammonia per joo c.c. Salaskin found 2.5 gm. NH3 per 100 c.c. in the saliv* of the dog. But in dogs with Pavlov's stomach pouch, and in ou gastric-fistula case, Mr. V., no saliva can enter the stomach or th< part of the stomach yielding the juice.
The ammonia of the duodenal content may be a factor, aj Boldyreff and others have shown the frequency with which intes tinal content enters the stomach. This factor is excluded in dog with the Pavlov stomach pouch. In our human fistula case thi factor is readily controlled by making the ammonia determination: only on those samples of gastric juice that are absolutely free fron admixture with bile, pancreatic juice, and succus entericus. Rose mann points out that the gastric-juice ammonia cannot be a simpl filtrate from the blood since normal blood contains only about o. mgr. of ammonia per 100 c.c.
Huber, working in the author's laboratory, found that intra venous and oral administration of ammonia salts increases th ammonia concentration in the gastric juice. It is decreased oi low, and increased on high protein diet. But when the urin ammonia is greatly decreased by taking alkalies, or greatly in creased by taking acids, the concentration of the gastric-juic ammonia remains unchanged.
The question of the origin of the gastric-juice ammonia i therefore very complex. (1) It is in part an active excretion fron the blood. (2) It may be formed in part by deamidization o amino-acids in the gastric mucosa. (3) It may be formed in th process of secretion of gastric juice, or (4) by the action of the HC on the gastric-juice protein, or on the cells of the mucosa. L cases of gastric ulcers of infectious origin it may come in part fron bacterial activity in the active focus of the ulcer.
In 1898 Nencki, Pavlov, and Zaleski found that, per unit o mass, there is more ammonia in the gastric mucosa than in an; other tissue of the body. These findings were essentially confirmee by Salaskin the same year. Huber found a greater concentratioi of ammonia in the fundic mucosa than in the mucosa of the cardia< and the pyloric ends of the stomach. These facts seem to indicate some relation of the ammonia formation to the secretion proces itself and to the protein absorption, unless the higher ammonia content of the secreting and absorbing mucosa represents ammonium chloride in the process of absorption from the gastric juice.