Studies in Thyroid Activity. 



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 Studies in thyroid activity. 



I. The Chemical Constituents of the Thyroid Gland. 



By E. C. Kendall. 



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



York City.} 



Interest in the chemical examination of the thyroid gland 

 centers around the iodine-bearing compound. The first attempt 

 made in this laboratory to separate and purify the iodine-bearing 

 compound consisted in dialyzing under varying conditions. The 

 entire gland was dissolved in sodium hydroxide and dialyzed from 

 collodion sacs. With running tap water only ten per cent, of the 

 total iodine would pass through the sac. At a temperature of 60 

 to 70 0 C. and under proper conditions of acidity, eighty per cent, 

 of the iodine would pass through the sac. These experiments led 

 to a study of the diffusibility of certain cleavage products of the 

 thyroid. As this study of the chemical constituents of the thyroid 

 is still being carried on, the details will be published later. The 

 results, however, may be briefly described as follows: 



A new method of treatment has been found by which the com- 

 plex proteins of the thyroid gland may be broken down into simpler 

 constituents which have not been described by previous investi- 

 gators. Among the products obtained uric acid and tryptophan 

 :n large amount are found. There are several non-iodine-bearing 

 compounds. The iodine has been found to exist in two distinctly 

 different compounds. These have been partially purified and a 

 compound containing 23.3 per cent, of iodine in organic combina- 

 tion has been separated. Of the non-iodine-bearing compounds 

 two are of especial interest. One reduces silver, gold, and mercury 

 in alkaline solution, and the other absorbs free iodine very readily. 

 In all, twelve distinct chemical compounds have been separated. 

 The properties of three of these show them to be still of high 

 molecular weight and they may, by further treatment, be divided 

 into still simpler compounds. 



