108 H. Victor Parker, et al. 



The similarity of the relative values for the extracellular 

 water and dissimilarity of the relative intracellular water 

 volumes in the two sexes gains further support from other 

 parts of the same study. As is seen in Table V, simultaneous 

 studies of total exchangeable sodium and potassium were 

 carried out in these patients according to the method des- 

 cribed by Moore and co-workers (1956). The total exchange- 

 able sodium which was determined through an independent 

 measurement demonstrates relative values very similar in the 

 two sexes. As about 85 per cent of the total exchangeable 

 sodium can be accounted for in the extracellular space the 

 findings can be taken as supportive evidence for the correct- 

 ness of the very close relative values for the extracellular 



Table V 



Body water compartments and total exchangeable 

 electrolytes in adults 



Sex Values related to body weight with standard error of the mean 



ECW Cle Nae ICW Ke 



(%) {m-equiv.lkg.) {m-equiv.jkg.) (%) (m-equiv.lkg.) 



Males 23-4 29-3 39-5 30-9 480 



±0-64 ±0-71 ±1-06 ±0-89 ±1-38 



Females 22-7 28-6 38-3 25-9 39-4 



±0-54 ±0-92 ±109 ±0-96 ±1-40 



water in the two sexes. The relative values for the total 

 exchangeable potassium which was determined independently 

 of the intracellular water demonstrate a pattern very similar 

 to the findings of the intracellular water. In both measure- 

 ments the females have a relative value about 20 per cent 

 below the males. As 97 per cent of the total exchangeable 

 potassium must be within the cells this finding can be taken 

 as evidence for the correctness of the measurements of the 

 intracellular water. It is worth mentioning that a calculation 

 of the average intracellular potassium concentration in the 

 two sexes results in very similar values: 152 m-equiv. per 

 litre intracellular water in the males and 149 m-equiv. per 

 litre intracellular water in the females, and thus indicates that 

 no difference in cellular composition exists in the two sexes. 



