PARATHYROID GLANDS 631 



ance of tetany, it is easy to understand why tetany is so much more com- 

 mon in children than in adults, since in the latter the thymus has been 

 largely replaced by connective tissue. He suggests, too, that the relation 

 of the thymus to tetany may explain the appearance of tetany during 

 pregnancy, for, though the parathyroid secretion of the mother would 

 suffice to neutralize the tetany threatening influence of the mother's largely 

 atrophic thymus, it might not perhaps be equal to the prevention of tetany 

 when her own thymus function is supplemented by thymus products en- 

 tering her blood from the intra-uterine fetus. 



The results of these experiments of Uhlenhuth, should they be con- 

 firmed by other workers, may prove to be of high importance for the 

 understanding of the pathogenesis of tetany. 



15. The Metabolism in Tetany 



With the rise of interest in biological chemistry, studies of the metab- 

 olism in all kinds of pathological processes have become popular, and it 

 is not surprising, therefore, that the results of a series of investigations 

 upon end metabolism and intermediary metabolism in tetany (both human 

 and experimental) should have already accumulated. Most of the studies 

 thus far made in tetany have dealt with the protein metabolism, the creatin 

 and creatinin metabolism, the carbohydrate metabolism, the mineral metab- 

 olism and the total metabolism in patients presenting the syndrome or in 

 animals in which the condition has been experimentally produced; but 

 relatively little attention seems to have been paid to the metabolism of 

 nucleins and purins, of fats, of lipoids, or of vitamins in tetany. 



An analysis of the results of these various metabolic studies on tetany 

 indicates that, on the whole, the metabolic processes are accelerated. This 

 might, perhaps, have been expected, in view of the general hyperex- 

 citability of the visceral nervous system that is known to exist in tetany. 



It is, of course, highly important that we should learn to understand, 

 not only the chemical and enzymatic composition of the internal secretion 

 of the parathyroid glands, but also the nature of the disturbances of the 

 body's chemical processes that follow upon parathyroidectomy ; for, once 

 we have obtained an intimate knowledge of the constitution of the para- 

 thyroid secretion and of the effects upon metabolism of parathyroid in- 

 sufficiency, we shall have gone far on the road towards a much desired 

 goal, namely, a knowledge of the exact pathogenesis of tetania 

 parathyropriva. 



Protein Metabolism in Tetany 



Studies of protein metabolism in tetany, aside from the demonstration 

 of its acceleration with increased output of total nitrogen in the urine, 

 have been pursued in three main directions: (1) the study of ammonia 



