166 



Scientific Proceedings (54). 



104 (800) 

 Studies in thyroid activity. 



II. The Specific Physiological Activity of Certain Con- 

 stituents of the Thyroid Gland. 



By E. C. Kendall. 



[From the Pathological Department of St. Luke's Hospital, New 



York City.] 



Investigations of the physiological activity of the thyroid 

 gland have shown that the internal secretion of the gland serves 

 many different functions. One or more of a series of symptoms 

 accompany cases of thyroid deficiency. These symptoms are 

 relieved by the administration of the thyroid gland of certain 

 animals, as the sheep, hog, and ox. When this treatment is 

 stopped the symptoms return. It would thus appear that the 

 functions of the internal secretion of the thyroid may be fulfilled 

 by furnishing the body with the constituents of the thyroid gland 

 from another animal. 



The separation of the various chemical constituents briefly 

 described above suggested the possibility of determining which 

 constituents controlled the various symptoms occurring in cases of 

 thyroid deficiency. 



The first step in the method of separation of the constituents 

 results in two solutions. One of these contains about 60 per cent- 

 of the total iodine and 9 per cent, of the nitrogen. This is desig- 

 nated " Solution A." The other, called " Solution B," contains 

 40 per cent, of the total iodine and 91 per cent, of the nitrogen. 

 In order to establish the physiological activity of these solutions» 

 experiments were carried out, first upon dogs, and then with cases 

 of thyroid deficiency. The number of cases treated is insufficient 

 to establish completely the physiological properties of these 

 solutions, but the results based upon a series of experiments with 

 two dogs extending over four months, with two typical cases of 

 myxedema, and with three cretins, are as follows: 



Solution A was found: (1) to affect the nitrogen metabolism 

 and hence the body weight and temperature; (2) to produce 

 tachycardia; (3) to cause nervousness and tremor; (4) to relieve 



