Effect of Adrenal Steroids on Body Electrolytes 189 



On sodium, Cortisol has similar retaining effects in females 

 as in males and these disappear in old animals (Fig. 11). 



As regards the enhanced sodium excretion which appears 

 later, females react differently from males. Instead of dis- 



8 9 f 



Fig. 8. Urinary sodium and potassium excretion of adrenalecto- 



mized male rats of different age groups treated with Cortisol 



(5 mg./kg.). 



Thick line : sodium excretion. 



Thin line : potassium excretion. 



Other figures as for Fig. 1. 



appearing with increasing age, the response remains high and 

 its onset is more rapid in ageing females, although in this 

 experiment animals of the adult group do not respond 

 clearly. 



The effect of Cortisol on potassium excretion in females is 

 similar to that observed in males, i.e. it is enhanced, the 

 effects tending to decrease in intensity with age. 



