Hormones and Water and Electrolyte Metabolism 91 



conclusions, of possible relevance to our main theme, are as 

 follows : 



Oestrogens. In men, the output of oestrogens remains re- 

 latively constant with increasing age; in women, on the other 

 hand, the output declines between the ages of 40 and 60 years, 

 reaching a level somewhat below that of men and thereafter 

 remaining constant. Of the separate fractions, oestrone and 

 oestradiol decline slowly in men, accompanied by an increase 

 in oestriol which makes the total oestrogen output appear 

 constant; in women the most marked decline in earlier 

 decades is in oestriol output, the least marked in that of 

 oestrone, while in the later decades further small declines in 

 oestrone and oestradiol are accompanied by an apparent 

 increase in oestriol. Oestriol is a metabolite, not a secretory 

 product as the other two may be ; its increase with advancing 

 age may therefore be due to lesser destruction of secreted 

 oestrogen. 



Neutral Steroids. The rate of decline of 17-ketosteroids is 

 similar in both sexes. The urinary ketonic androgens are 

 higher in men than in women and decline more steeply in the 

 former, particularly during the earlier decades. During these 

 decades, the decline of androgens is steeper than that of 17- 

 ketosteroids, so that with advancing age the ratio of 17- 

 ketosteroids to androgens increases, albeit somewhat irregul- 

 arly. Since the androgenic activity of the 17-ketosteroids is to 

 be attributed chiefly to androsterone, it follows that the rate 

 of production of androsterone (and presumably of its pre- 

 cursors) decKnes more rapidly than that of the less andro- 

 genically active 17-ketosteroids. Though this might have been 

 expected for men, as a result of declining testicular function, it 

 is perhaps more surprising in women and suggests a decrease 

 in output of either adrenal or ovarian androgens, or both. 



The ratio of androgens to oestrogens is higher for men 

 than for women at all decades until the ninth. 



The output of adrenal corticosteroids is rather higher in 

 men than in women at all ages and varies but little with age. 

 In contrast, the non-ketonic steroids, a mixture of substances 



