THE PITUITARY AND THE THYROID 



tomy or after both thyroidectomy and hypophysectomy 

 (Hoskins and Hoskins, 1920; and Allen, 1920, 1929). ^ 



The thyroid-pituitary interrelationship in birds. — The ob- 

 servations which have so far been made in birds (duck: 

 Schockaert, 1931, 193-; pigeon: Larionov and co-workers, 

 1 93 1, Riddle, Bates, and Dykshorn, 1933, Thurston, 1933; 

 fowl: Domm and van Dyke, Noether, 1932, Domm, and 

 Foster, Gutman, and Gutman, 1933) indicate that the ad- 

 ministration of implants or the injection of crude suspensions 

 or extracts of the anterior pituitary cause hypertrophy and 

 signs of hypersecretion of the thyroid similar to that produced 

 in the mammal. 



Although Schockaert (1930) at first denied that the effects 

 on the duck-thyroid and thymus were specific, his later ex- 

 periments led to the opposite conclusion. After ducks had 

 been treated several weeks, exophthalmos and emaciation 

 often appeared. At necropsy the heart was found to be en- 

 larged. The lobes of the thyroid were hypertrophied and 

 weighed three to eight times as much as those of control 

 ducks. The anatomical changes in the thyroid were those 

 usually considered as accompanying an increased rate of thy- 

 roid secretion (enlargement and proliferation of acinous cells, 

 disappearance of colloid, etc.). The retrogression of the thy- 

 mus in the immature duck was caused only by the adminis- 

 tration of anterior pituitary. Schockaert and Foster (1932) 

 particularly studied the iodine content of the duck's thyroid 

 after the administration of anterior pituitary. They conclud- 

 ed that I week's treatment reduced the total iodine to its 

 lowest level, but that with further treatment the concentra- 

 tion of iodine diminished because the thyroid continued to 

 undergo hypertrophy. 



Noether (1932) observed that the administration of an ex- 

 tract of the anterior lobe to hens caused a proliferation of the 

 cells of the thyroid as well as a loss of colloid. The presum- 



i Also see Uhlenhuth (1923). 



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