THE PITUITARY AND THE THYROID 



did not observe any change in the dog or man. Anselmino 

 and Hoffmann (1934) beheved that a "ketogenic hormone" 

 could be separated from the thyrotropic hormone by suitable 

 extraction of the anterior pituitary. 



Pugsley and Anderson (1934) found that a thyrotropic ex- 

 tract caused an increase in the fecal excretion of calcium by 

 the rat at about the time the basal metabolic rate was raised. 

 Creatine excretion in the rat and dog was also elevated fol- 

 lowing the administration of thyrotropic extract (Pugsley and 

 others, 1934). According to Houssay (1934) the specific 

 dynamic reaction to proteins is normal in hypophysectomized 

 dogs unless the thyroid has also been removed (in which case 

 it is lowered). Therefore, the thyrotropic hormone appears 

 to play no part in this metabolic response. 



Substances which prevent thyroid stimulation by the anterior 

 pituitary. — ^The administration of potassium iodide, Lugol's 

 solution, or di-iodotyrosine is said to lessen or even to prevent 

 the thyroid-stimulating effect of anterior-lobe extract (Silber- 

 berg, 1929, 1930; Okkels and Krogh, 1932, 1933; and Elmer, 

 1933). Siebert and Thurston (1932) as well as Okkels and 

 Krogh, and Friedgood (1935) concluded that the increase in 

 basal metabolism characteristically following the injection 

 of a potent anterior-lobe extract could be prevented or con- 

 verted into a decrease below the normal level by the adminis- 

 tration of iodine or iodides. According to Loeser and Thomp- 

 son (1934), potassium iodide has no effect on the thyroid of 

 the hypophysectomized rat whether or not thyrotropic hor- 

 mone is also administered. They concluded that potassium 

 iodide, depending upon the dose, diminishes or increases the 

 secretory activity of the pars glandularis thus indirectly af- 

 fecting the thyroid.'^ Most of such experimental evidence 



'^Marine, Rosen, and Spark (193O studied the effects of potassium iodide or 

 desiccated thyroid on the pituitary of goitrous or thyroidectomized rabbits. They 

 observed that the anatomical abnormalities in the pars glandularis after thyroidec- 

 tomy could be corrected by desiccated thyroid but not by potassium iodide. 



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