346 



Preliminary Note on the Origin of the Hydrochloric Acid in the 



Gastric Tubules. 

 By Mabel Pukefoy FitzGerald (Oxford). 



(Communicated by Prof. A. B. Macallum, F.R.S. Eeceived March 7, — Read 



March 10, 1910.) 



(From the Biochemical Laboratory of the University of Torouto.)* 



The place of origin in the peptic glands of the hydrochloric acid of the 

 gastric juice has been, during the last 60 years, a question the solution of 

 which has been directly attempted by a number of observers whose efforts have 

 on the whole been unsuccessful. 



The first to attack the question was Claude Bernard, who sought to localise 

 the acid formation in the glands by injecting into the blood-vessels of a 

 rabbit, first a solution of lactate of iron and thereafter one of potassium 

 ferrocyanide. When the two solutions, mingle in the circulating fluid and 

 tissues of the body the mixture should, he assumed, only give the Prussian 

 blue reaction in the presence of a free acid, and, in consequence, when diffused 

 through the gastric glands, it should develop the blue reaction where the 

 liydrochloric acid is formed. The assumption is not quite correct. The 

 mixture of the two solutions, as soon as it is made, in the test-tube, 

 develops Prussian bhie even wlien tlie purest reagents are employed and, 

 therefore, though tlie addition of an acid greatly enhances the blue reaction, 

 the latter is not infallible evidence of tlie occurrence of a free acid. With 

 this method, however, liernard found a blue deposit on the surface of the 

 mucosa in the lesser curvature of the stomach, but no trace of blue in the 

 interior of the mucosa. This result left the (piestion undecided. 



Other observers also employed this method, but with a like result. Even 

 with aniline dyes which, reacting with acids, give a different colour, the 

 histolosical elements concerned in the formation of the acid could not be 

 determined. 



All the facts known regarding tlie structure of the pe2)tic tubules in 

 Mammals seem t.o indicate that the cells engaged in the formation of the acid 

 are those known as parietal. 



'J'liis has now l)een directly confirmed, and by tlie use of Claude Bernard's 

 njotliod. lu this, liowever, the citrate of iron and ammonia replaced the 

 lactate salt which he used. Mixtures of solutions of the double citrate salt 



* Kesearcli ciinii^il out wliilc liohliiitf a Trav(?Ming Fi-llow.Hliii) of tho Rockefeller 

 IiiHtitntc! for Medical ItcHcanli, New York, 190H. 



