THE EFFECTS OF HYPOPHYSECTOMY 



physectomy^ contains many contradictory results largely ow- 

 ing to the failure properly to evaluate complications due not 

 to the removal of the gland but to injury of the brain. The 

 belief that the pituitary body is essential for life — formerly 

 shared by Paulesco, Gushing, Biedl, Blair Bell, and others — 

 certainly is not true of the dog, in which most of their experi- 

 ments were performed. It is reasonable to conclude that their 

 results depended upon an unrecognized injury of the hypo- 

 thalamus.-' The evidence today, from reports of successful 

 hypophysectomy of fish, amphibia, reptiles, birds, and mam- 

 mals, indicates that the operation is compatible with the sur- 

 vival of animals for weeks or months except in the case of the 

 fowl, which is said to succumb within a few days. For the 

 most part, the data show that the pars glandularis is the only 

 important division of the pituitary body in mammals. In 

 some, but not all, cold-blooded animals the internal secretion 

 of the pars intermedia is necessary for the control of the dis- 

 persion of pigment-granules, particularly in the melano- 

 phores. Extirpation experiments offer little support for the 

 belief that the pars neuralis is physiologically important. 



THE EFFECTS OF THE EXTIRPATION OF THE PITUITARY 

 BODY OF FISH, AMPHIBIA, AND REPTILES 



The effects of hypophysectomy in fish. — No detailed studies 

 of the effects of hypophysectomy in fish appear to have been 

 made. Orias (1932) was particularly interested in the carbo- 

 hydrate metabolism in the dogfish {Mustelis canis) after hy- 

 pophysectomy, after pancreatectomy, and after both oper- 

 ations had been performed. He reported that the concentra- 

 tion of glucose in the blood was much higher after pancrea- 



^ In a strict sense, the term "hypophysectomy" should refer to the removal of the 

 tissues derived from Rathke's pouch; in accordance with common usage, however, 

 it is here used to refer to the removal of the pituitary body. 



3 Dandy and Reichert (1925) pointed out that increased intracranial tension may 

 be in part responsible for post-operative symptoms. 



[3S\ 



