. ; & 



Reprinted from THE JOURNAL OF BIOLOGICAL CHEZJ^TRY, Vol. XLV, No. 2, 1921 



A STUDY OF THE DISTRIBUTION OF IODINE BETWEEN 

 CELLS AND COLLOID IN THE THYROID GLAND. 



II. RESULTS OF STUDY OF DOG AND HUMAN THYROID GLANDS. 



BY HARRY BENJAMIN VAN DYKE. 



(From the Laboratory of Physiological Chemistry and Pharmacology, 

 . University of Chicago, Chicago.} 



(Received for publication, November 29, 1920.) 



In the first paper of this series Tatum 1 described a method 

 whereby thyroid cells may be separated from colloid material 

 and examined chemically. Briefly the method consists in cutting 

 frozen sections of the thyroid gland and floating these sections 

 on Ringer's 2 solution. The colloid material immediately drops 

 out of the acini and is presumably dissolved in the Ringer's solu- 

 tion. The cells may then be separated by centrifugalization, 

 dried, weighed, and analyzed. Comparisons between the iodine 

 content of cells so separated and the iodine content of control 

 pieces of unsectioned whole gland may indicate the distribution 

 of iodine between cells and colloid under different functional 

 conditions. 



In this paper I wish to report the results of a study, suggested 

 by Dr. A. L. Tatum, of the distribution of iodine in the thyroid 

 glands of normal and iodine-fed dogs as well as in human glands 

 obtained from individuals subjected to operation for toxic goiter. 

 The method earlier described by Kendall 3 was used in making the 

 final iodine determinations. 



Incidental to the determination of the iodine distribution in 

 dog and human thyroid glands, some control experiments were 

 performed relative to the alterability of the intracellular iodine 

 concentration during the process of cutting. It may be argued 

 that a portion of the iodine-containing compound diffuses from 



1 Tatum, A. L., J. BioL Chem., 1920, xlii, 47. 



2 Campbell, J. A., Quart. J. Exp. Physiol., 1911, iv, 1, Formula "A." 



3 Kendall, E. C., J. BioL Chem., 1914, xix, 251. 



325 



THE JOURNAL OF BIOLOGICAL CHEMISTRY, VOL. XLV NO. 2 



520421 



