After the administration of antithyroid drug, thyroid substance or thyroid stimulating hormone, the weight, the uptake of Radioiodine and iodization in the rat thyroid gland were studied.
The separation of the thyroxine from other iodine containing compounds of the thyroid gland were based on the method of Taurog, Chaikoff. The results obtained from the study are as follows: 1) The thyroid gland of rat in which hormonal synthesis was blocked by methiocil showed the secondary decrease of I131 uptake and compensatory hypertrophy and increase of weight by the T. S. H. 2) The administration of Thyreoidin produced the decrease of I(131) uptake and thyroid weight, and the atrophy of the thyroid gland. It's due to the depressing of hormonal synthesis and secretion in the thyroid gland in accordance with the decrease of T. S. H.
It means the hypofunction of the thyroid gland. 3) The administration of T. S. H. produced an increase of I(131) uptake by the thyroid gland and an increaseof hormone secretion, showing hyperfunction of thyroid gland.