ADRENALECTOMY 143 



FACTORS DETERMINING THE SURVIVAL PERIOD AFTER 

 ADRENALECTOMY 



Adrenalectomized animals are extremely sensitive to trau- 

 matic injury or hemorrhage and hence a finesse of surgical 

 technique will be a factor in determining survival after ad- 

 renalectomy. The shock of trauma and hemorrhage involved 

 in prolonged and clumsy handling of the viscera will obviously 

 shorten the life of an already doomed animal. In addition to 

 surgical technique, however, a number of other factors will 

 determine the survival period, chief among which are the 

 following : 



1) the animal species 



2) the age of the animal 



3) the pre-operative treatment 



4) the anesthetic and the duration of its administration 



5) the completeness of the extirpation 



6) the post operative treatment 



7) the season of the year 



S) the state of the reproductive system 



Some animals (e.g., the rat, goat, and frog) survive adrenalec- 

 tomy much longer than others (e.g., the dog or guinea pig) 

 which is in accord with their comparative hardiness and ability 

 to withstand other forms of injury. 



Age. Age is an important factor in determining the sur- 

 vival of a given animal species. Young animals survive for 

 much shorter periods than adults. It is probable that the 

 active metabolism and growth processes of the young individual 

 induce a rapid depletion and more urgent demand for the 

 cortical hormone than the relatively inactive tissues of the 

 adult. In accord with this view is the fact that adrenalec- 

 tomized young animals require relatively more of the cortical 

 hormone than adults to maintain them in good condition. 



The effect of age in determining the survival of animals after 

 adrenalectomy has been demonstrated in rats by Firor and the 



