THE EFFECTS OF HYPOPHYSECTOMY 



centration of the blood sugar. Such lesions were not followed 

 by atrophy of the testes. 



The effects of lesions of the hypothalamus in mammals. — 

 Aschner pointed out (1912 and subsequently) that the rapid- 

 ly fatal effect of hypophysectomy in Paulesco's dogs, as well 

 as the condition described by Gushing and his collaborators 

 as a cachexia hypophyseopriva^ were probably due to an in- 

 advertent injury of the tuber cinereum. Among the effects 

 of injury of the stalk or tuber cinereum mentioned by Asch- 

 ner were slowing and weakening of the pulse, bradycardia, 

 slowing of the respiratory rate (sometimes with "vagal 

 breathing"), and glycosuria. Aschner believed that young 

 dogs more often survived hypophysectomy without compli- 

 cations attributable to hypothalamic lesions because the pia- 

 arachnoid, being more delicate, could be torn during the 

 operation with less likelihood of injury of the adjacent nerv- 

 ous tissue. Dandy and Reichert also emphasized that in- 

 creased intracranial tension was probably a major contribu- 

 tory cause of death in the acutely fatal outcome of many 

 hypophysectomies performed in dogs by the temporal route. 



Of greater interest today is the part played by the hypo- 

 thalamus in the metabolism of water, salts, carbohydrates, 

 and fats. For, particularly in dogs, hypophysectomy may be 

 followed by polyuria, perhaps by changes in the distribution 

 of certain inorganic salts, by glycosuria, and by obesity. All 

 these symptoms are probably never observed simultaneously 

 in one animal. The most frequently reported symptom is a 

 polyuria'^ which may be slight and transient if hypophysec- 

 tomy is performed with great care. Most of the observations 

 have been made in dogs; some experiments have also been 

 performed in rats, cats, and rabbits. In the following ac- 

 count, the statements refer to experiments in dogs unless 

 another animal is mentioned. 



The relation between the hypothalamus and the metabolism of 



'^ Particularly in young dogs (Houssay and Hug, 1921). 

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