Discussion 97 



retain water before birth and still excretes high amounts of oestrogens 

 after birth, that the persisting influence of the mother's oestrogens in the 

 early days of life might be the explanation of the infant's poor response 

 to a water load. 



Adolph: This oestrogenic influence seems to me a very interesting 

 possibility. Has anyone any data on the influence of the maternal 

 hormones upon water balances or exchanges? 



Fourman: Another question is whether oestrogens do inhibit the 

 diuretic response to an overdose of water in adults. 



Heller: We have been injecting sex hormones of various kinds into 

 newborn rats to see whether we could influence the amount of total body 

 water or whether we could retard its decrease as the animals get older. 

 These are only preliminary experiments, but so far neither oestrogens 

 nor progesterone have produced any effect. 



Swyer : Gans and Thompson (1957) produced evidence that the hydrae- 

 mic neonate might retain fluid as a result of maternal oestrogens, and 

 that as maternal oestrogens were excreted, the weight fell and then 

 remained reasonably constant. So it does look very much as though at 

 least some of the fluid retention in the newborn infant is due to maternal 

 oestrogen. I do not think that that can be held to account for the poor 

 handling of the water load since that extends for the best part of the 

 first year, or so I understand. 



McCance: No, only about 14- days, I believe. 



Adolph: I think I can clarify this contradiction of ages to some extent. 

 If you read the literature up to 1923 you learn that in the first year the 

 human infant excretes water very slowly. Such conclusions were re- 

 ported by Lasch (1922. Z. Kinderheilk., 36, 42) and others, with inade- 

 quate methods of collecting urine. The problem was clarified when 

 Ames (1953. Pediatrics, Springfield, 12, 272) did some well-controlled 

 studies on the excretion of a water load in infants of 1, 3, 7, and 14 days 

 of age. She showed that within 14 days the excretion of a water load 

 becomes 63 per cent as great, and within 90 days even as great as in 

 the adult human, if one bases water load and excretion on unit body 

 weight. 



Swyer: Does this also apply to resistance to dehydration and handling 

 of electrolytes? 



Adolph: I do not think we have any good data on the resistance to 

 dehydration. We know much less about hydropaenia than we do about 

 superhydration . 



Widdozvson : Dr. Talbot, if a newborn baby and an adult were deprived 

 of all water, which would live longer, and why? 



Talbot : The minimum daily water expenditure of the small infant rela- 

 tive to his body water stores is ordinarily about twice as great as it is in 

 the adult. For this reason, the infant usually tends to become dehydrated 

 when deprived of water about twice as fast as the adult. If only this 

 relationship is taken into account, one would expect the adult to outlive 

 the infant. However, the infant is born with a "surplus" of water, 

 equivalent to about one day's water requirements, which he is meant to 

 shed during the first few days of life. The shedding of this surplus fluid 



AGEING — IV — 4 



