CHAPTER XXVIII 



EFFECTS ON THE HYPOPHYSIS 



Although as yet but imperfectly known, it appears that the changes pro- 

 duced in the hypophysis (pituitary gland) may be responsible for some of the 

 general phenomena of inanition and malnutrition. After a brief summary, 

 the effects of inanition upon the hypophysis will be considered in detail under 

 (A) total inanition and (B) partial inanition. 



Summary of Effects on the Hypophysis 



Although the data concerning the effects of inanition upon the hypophysis 

 are comparatively scanty, it appears that during total inanition, or on water 

 only, in the human species (adult and infant) there is a definite loss in weight, 

 though as a rule relatively less than in the body as a whole. This usually 

 applies also to adult animals (rat), but in the young during chronic underfeeding 

 at constant body weight there may be a continued increase in weight of the 

 hypophysis, amounting to a maximum of 33 per cent. 



Volumetric analysis shows during inanition in the rat certain changes in 

 the relative size of the hypophysis lobes, in proportions of parenchyma and of 

 vascular stroma, and in nucleus-plasma ratio; these changes varying according 

 to age and type of inanition. 



In histological structure, only slight changes during inanition have been 

 observed in the neural and intermediate lobes; but in the anterior lobe there 

 is a variable degree of atrophy and degeneration of the parenchyma cells, with 

 a tendency to loss of the specific cell granulation. Mitosis, which is frequent 

 in the young, is more or less completely suppressed by inanition, but is resumed 

 promptly upon refeeding, with ultimate recovery of normal size and structure 

 of the hypophysis. 



During hibernation, atrophic changes of questionable significance have 

 been described in the hypophysis, but the findings in the most recent work 

 have been negative in character. Upon awakening in the spring, even before 

 feeding, hypertrophy of the hypophysis and cell-changes associated with the 

 rutting season may occur. 



From the few observations during partial inanition, the hypophysis appar- 

 ently decreases in weight in experimental rickets, increases in scurvy, and 

 undergoes little or no change in beriberi and aqueous inanition. The histo- 

 logical changes in the hypophysis during partial inanition appear uncertain 

 or inconstant. 



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