PARATHYROIDS AND CALCIUM METABOLISM. 



By EDUARD UHLENHUTH. 



{From the Laboratories of The Rockefeller Institute for Medical Research) 



(Received for publication, November 27, 1918.) 



MacCallum and Voegtlin,! as well as other authors, have found that 

 in tetany resulting from the extirpation of the parathyroids the Ca 

 content of the blood and the organs (brain) is greatly reduced and 

 that the introduction into the organism of Ca salts, subcutaneously, 

 intravenously, or per os, suppresses the tetanic convulsions of the ani- 

 mals operated on. These findings have been confirmed recently by 

 Howland and Marriott^ in tetany of children. Spontaneous tetany 

 in human beings has apparently the same cause as parathyreoprival 

 tetany, both being due to the non-functioning of the parathyroids. 

 Furthermore, it is known^ that after parathyroidectomy, tetanic con- 

 vulsions may be suppressed by bleeding the animals and substituting 

 the amount of blood drawn by an equal amount of salt solution. 

 From the latter fact MacCallum and Voegtlin conclude that in the 

 absence of the parathyroids some toxic substance accumulates in the 

 blood, which normally is antagonized by the parathyroids. They 

 assume further that the toxicity of this substance is due to its abihty 

 to combine, in some unknown way, with calcium which it extracts 

 from the organs, causing its excretion and thereby diminishing the 

 Ca content of the blood and organs. MacCallum thinks that the 

 muscular convulsions in tetany are the result of the diminution of 

 the Ca concentration, the function of the parathyroids being to regu- 

 late the Ca concentration by antagonizing the toxic substance and 

 thus preventing it from extracting the Ca salts from the body. 



As regards the existence of a toxic substance involved in the causa- 

 tion of tetany, the writer has shown that such a substance actually 



1 MacCallum, W. G., and Voegtlin, C, /. Exp. Med., 1909, xi, 118. 



2 Howland, J., and Marriott, W. McK., Bull. Johns Hopkins Hosp., 1918, 

 xxix, 235. 



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