THE PITUITARY BODY 



of the "antihormone" could not be described as antithyroid. 

 Such a conclusion, however, leaves out of account the fact 

 that the true thyroid secretion is not necessarily thyroxin. 

 The report of Collip and Anderson that "antithyrotropic" 

 hormone causes a reduction of the basal metabolic rate of the 

 rat speaks against the possibihty that the internal secretion 

 of the thyroid is the "antihormone" (thyroid extract, among 

 other substances, may lessen or prevent thyrotropic effects). 

 According to the observations of Eitel and Loeser, the thy- 

 roidectomized wether is unable to produce "antihormone" 

 in response to the injection of thyrotropic hormone. '^ 



The compensatory hypertrophy of thyroid tissue remain- 

 ing after partial thyroidectomy in the dog has been prevented 

 by hypophysectomy (Houssay, Biasotti, and Magdalena, 

 1 932 ; and Kahler, 1 934) ; on the other hand, Houssay, Biasot- 

 ti, and Mazzocco (1932) could restore the compensatory 

 hypertrophy of the thyroid in the hypophysectomized dog as 

 well as greatly increase it in the normal animal by the admin- 

 istration of anterior pituitary extract. Silberberg (1933) and 

 Moore (1933) studied the effects of anterior pituitary ex- 

 tracts on compensatory hypertrophy in otherwise normal 

 guinea pigs. Transplants of thyroid tissue were found to be 

 stimulated and to survive better if the recipient guinea pigs 

 received injections of anterior pituitary extract (Silberberg, 



1934)- 



Krayer (1933) bilaterally extirpated the cervical sym- 

 pathetic of guinea pigs and rabbits; he then administered a 

 potent thyrotropic extract days to months after operation. 

 Both the anatomical changes and the rise in basal metabolism 

 were nevertheless unchanged. Pieper (1934) unilaterally 

 denervated the thyroid of the rabbit. He also concluded that 

 denervation had only a slight effect on the response (his- 

 tologic) of the thyroid to thyrotropic hormone. According 



'■* Magistris (1935) believed that an "antithyroid" substance can be extracted 

 from the pars glandularis. 



[264] 



