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ADVENTURES IN RADIOISOTOPE RESEARCH 



the low potassium content of the plasma and the high content of the 

 tissue cells, the additional outlet opened by the intrusion of ^^K into 

 the cells in experiments taking one hour, makes out about five times the 

 normal outlet of intrusion of these ions into the interspaces. 



The total water content of the cells can be entirely replaced by labelled 

 water. Since the volume of the cellular body water is about twice as 

 large as that of the extracellular fluid through the intrusion of labelled 

 water into the cells a substantial additional outlet of the labelled water 

 molecules of the plasma is opened. 



Table 3. — Rate of Disappearance of -*Na from 

 THE Circulation of Rabbits Weighing 2.7 kgm 



As to the phosphate ions, not only that they diffuse into the tissue 

 cells but they are also incorporated into the the bone apatite. These 

 additional outlets may be made responsible for the fact that the ^^P 

 loss of the plasma is found to be very much greater than the 24Na loss 

 during the same time. 



While the additional outlets mentioned above for potassium, phos- 

 phate, and water will be responsible for the high values of the volume 

 of the diluting body fluid observed for these elements in experiments of 

 comparatively long duration, the fact that also after the lapse of ^ min 



