THE INFLUENCE OF CALCIUM AND BARIUM ON 

 THE SECRETORY ACTIVITY OF THE KIDNEY.^ 



BY 



JOHN BRUCE MacCALLUM, M. D. 



From the Rudolph Spreckels Physiological Laboratory of the 

 University of California. 



In previous publications^ it was shown that subcutaneous or 

 intravenous injections of small quantities of solutions of certain 

 salts, including the saline purgatives, produce not only increased 

 peristalsis, but also an increased secretion of fluid into the in- 

 testine. This was found to be true also when the solutions were 

 applied locally to the peritoneal surfaces of the intestine. It was 

 suggested that the main actions of saline purgatives consist in 

 the production of increased peristaltic movements, and of in- 

 creased secretion of fluid into the intestine; and that the semi- 

 fluid foeces which are produced by saline purgatives are the 

 result not of decreased power of absorption by the intestine, 

 but of an increased secretion of fluid into the intestine. It was 

 further shown that the administration of calcium or magnesium 

 chloride tends to suppress the peristaltic movements and the secre- 

 tory activity of the intestine. Attention was specially called to the 

 marked action of barium chloride in the production of violent peri- 

 staltic movements and ringlike constrictions in the intestine, and 

 also in the production of an increased flow of fluid into the intes- 

 tine. It was also pointed out that the production of these activi- 

 ties in the intestine by the purgative salts, and their suppression 

 by calcium and magnesium is analogous to the production and 

 suppression of rhythmical contractions in voluntary muscles de- 



1 A preliminary report of these experiments was published in the University 

 of California Publications, Physiology, January 15, 1904, Vol. I., No. 10, p. 81. 



2 MacCallum, J. B. — American Journal of Physiology, Vol. X., No. III., 

 p. loi, 1903, and Vol. X, No. V, p. 259, 1904. 



