Effect of Adrenal Steroids on Body Electrolytes 187 



followed, in contrast to the situation for male animals, by a 

 very pronounced and rapid rise (more in adult than in old 

 animals) to high positive values (+0-95 and +1'28, re- 

 spectively), this effect tending to return within control values 

 in the ninth hour. 



1.6 



hi 



1,0 



dd 



0,6 

 OA 



o,z 



0,2 

 0,1 

 Q6 

 0,8 

 1,0 

 1,2 



U . ^ ^ 



/ 2 54? (J 7 5 9/ 



Fig. 6. Urinary sodium/potassium ratio of adrenalectomized female 



rats of different age groups treated with aldosterone. 



Figures as for Fig. 3. 



Effect of Cortisol 



On urinary output, Cortisol has, as is well known, a marked 

 enhancing effect (Marcus, Romanoff and Pincus, 1950; 

 Desaulles, Schuler and Meier, 1955). In male rats this effect is 

 well developed, and ageing does not seem to modify it 

 markedly (Fig. 7.) 



On sodium, Cortisol exerts initially a sUght retaining effect 

 that has already been reported (Dorfman, 1949; Johnson, 



