186 



P. A. Desaulles 



On potassium excretion the enhancing effects of aldo- 

 sterone are more marked and begin at an earlier age than in 

 males, old animals showing the most pronounced effect. 



On the sodium/potassium ratio the effects are much more 

 marked than in the case of males (Fig. 6). Young animals 

 respond with a reduction that is marked ( —0 • 90), but of slow 



% 

 zco 



ISO 

 14^ 

 120 

 100 

 30 

 60 

 40 



20 



+ 

 



20 



40 



60 



60 



9 t 



Fig. 5. Urinary sodium and potassium excretion of adrenalecto- 

 mized female rats of different age groups treated with aldosterone. 

 Figures as for Fig. 2. 



onset (maximum in the fifth hour), the values returning to 

 within control limits at the end of the experiment. 



In adult and old females, the reduction in the sodium/ 

 potassium ratio is more intense (—1-29 and —1-40 respect- 

 tively) and rapid in onset (maximum in the first collecting 

 period). This effect lasts longest in old animals. 



The rapid lowering of the sodium/potassium ratio is 



