HORMONAL ASPECTS OF WATER AND 



ELECTROLYTE METABOLISM IN RELATION 



TO AGE AND SEX 



G. I. M. SWYER 

 Obstetric Hospital, University College Hospital, London 



Nearly all the hormones may have some influence on 

 water and electrolyte metabolism. However, for most of them, 

 this effect is indirect and occurs only under highly abnormal 

 circumstances. Thus, the dehydration which exists in un- 

 controlled diabetes mellitus or in hyperparathyroidism is the 

 result, respectively, of gross deficiency of insulin or excess of 

 parathormone, and certainly does not point to any physio- 

 logical role of these hormones in water metabolism. The same 

 is essentially true of thyroid hormone and, though perhaps 

 with reservations, of the sex hormones and gonadotrophins. 

 Only posterior pituitary antidiuretic hormone (ADH) and 

 certain of the adrenocortical steroids are directly concerned 

 with the day-to-day and minute-to-minute adjustments 

 needed to maintain fluid and electrolyte homeostasis in mam- 

 mals. The major details of this hormonal control are well 

 known and it is not necessary to relate them here. It is pro- 

 posed, on the other hand, to examine how the influence of 

 hormones on fluid and electrolyte balance differs at various 

 ages and in the two sexes. In general, it is fair to say that 

 little attention has been paid to considerations such as these, 

 and for the most part knowledge is meagre. 



In Infancy 



Fluid and electrolyte control is notoriously inefficient at 

 birth and during the first few weeks or so of life. The late 

 development of the loop of Henle is generally considered to 

 be responsible for this (Hubble, 1957), the infant kidney being 

 unable, in consequence, to vary tubular reabsorption of water 



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