On the Physiology of the Thyroids. 121 



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On the physiology of the thyroids. 



By L. B. STOOKEY. 



[From the Physiological Laboratory, Medical School, University of 

 Southern California.^ 

 It seemed possible that many of the symptoms following 

 thyroidectomy, namely, decreased metabolism, accumulation of 

 mucoid in the subcutaneous connective tissues, colloidal changes in 

 the kidneys and liver, hyaline degeneration in the arterial walls, 

 decreased development of bones, delayed ossification of epiphysial 

 cartilages and synchondroses, disturbances in temperature, and 

 decline in muscular tone might result from decreased or incom- 

 plete protein oxidation. Conversely, this hypothesis would imply 

 that the thyroids exert an influence over some intracellular oxida- 

 tive processes. 



To throw light on this hypothesis the power of tissues taken 

 from normal animals to oxidize indol was compared with that of 

 tissues taken from thyroidectomized dogs. The dogs were bled 

 from the carotids, the organs removed under the usual precautions, 

 hashed, divided into convenient quantities and exposed to seven 

 times their weight of 0.005 P er cent, indol solution. Toluol was 

 added to prevent bacterial action. The mixtures were kept at 

 body temperature, and the amount of unoxidized indol was deter- 

 mined at varying intervals. The indol was estimated colorimetric- 

 ally by means of the glyoxylic acid reaction. Results obtained in 

 this manner were checked by Kjeldahl nitrogen determinations. 



In all cases it was found that thyroidectomy led to a decreased 

 power on the part of the liver, kidneys, and spleen to oxidize indol, 

 These findings might seem to indicate that the thyroids bear to 

 intracellular nitrogenous oxidation a relation analogous to that 

 existing between the pancreas and the utilization of glucose, 

 namely : the thyroids through their internal secretion activate the 

 oxidizing enzymes of the different body cells. 



