REMOVAL OF THYROID 311 



RELATIONS OF THE THYROID GLAND TO CARBOHYDRATE 



METABOLISM 



We next turn to a no less knotty and troublesome sub- 

 ject, the problem of the relation of the thyroid gland to the 

 carbohydrate metabolism of the body. 



Removal of the Thyroid and of the Parathyroids. In or- 

 der to prevent confusion it is necessary to strictly differenti- 

 ate between the thyroid gland and the parathyroid bodies. 

 From studies of cases of myxcedema 37 and upon dogs after 

 extirpation of their thyroids, a decided increase of sugar 

 tolerance has been observed following loss of the thyroid 

 function, and with this a marked general slowing of the 

 transformation processes. 38 Thus a dog without its thyroid 

 can tolerate very large quantities of ingested sugar without 

 the appearance of an alimentary glycosuria. So, too, 

 adrenin glycosuria may fail to appear in different animals 

 under certain conditions (although by no means always) 

 after extirpation of the thyroid. 39 Eemoval of the para- 

 thyroids, however, has precisely the opposite effect (as indi- 

 cated in the studies of E. Hirsch, Underbill and Saiki, and of 

 Eppinger, Falta and Eudinger). Even after extirpation 

 of three parathyroids in dogs there may be noted, in the 

 course of a latent tetany (which is without spasmodic 

 twitching and is only told by a typical change in electrical 

 excitability), an enormous lowering of the assimilation limit 

 for grape-sugar. If there be combined with the extirpation 

 of several of the parathyroids also extirpation of the pan- 

 creas, a marked rise in the protein exchange in fasting and 



" J. Hirschl, W. Knopf elmacher (cf. Vol. I of this series, p. 439, Chemistry 

 of the Tissues) and C. v. Noorden, Die Zuckerkrankheit, 5th ed., p. 47, 1910 



'"Pari, Falta and Gigon, H. Eppinger, W. Falta, C. Rudinger (v. Noor- 

 den's Clinic), Zeitschr. f. klin. Med., 66, 1908; 67, 1909. 



" Eppinger, Falta and Rudinger, 1. c. ; E. P. Pick and F. Pineles, Biochem. 

 Zeitschr., 12, 473, 1908; F. P. Underbill and W. H. Hilditch, Amer. Jour, of 

 Physiol., 25, 66, 1909; F. P. Underbill, ibid., 27, 331, 1911; Ritzmann 

 (Straub's Lab.), Arch. f. exper. Pathol., 61, 231, 1909; E. G. Grey and W. T. 

 de Santelle (Johns Hopkins Univ., Baltimore), Jour, of Exper. Medicine, 11, 

 659, 1909; J. McCurdy, ibid., 798. 



