764 



ADVENTURES IN RADIOISOTOPE RESEARCH 



To eacla of the outgrown rats I to IV 5 mgm nucleic acid were administer- 

 ed. To the full-grown rats V to VIII and the growing rats IX to XII 



Table 3. — Percentage ^ap Introduced as Labelled Desoxyribosbnucleic 

 Acid Present After 2 hr in Plasma and Different Organs 



Eat 



Plasma 



Liver 

 free P 



Liver acid 

 soluble P 



Liver 

 total P 



Spleen 

 total P 



I 



Kidney 

 total P 



' Plasma 

 (present 

 as free 

 P only) 



I 



II 



Ill 



IV 



V 



VI 



VII 



VIII 



IX (blood) 



X (blood) 



XI (blood) 



XII (blood) 



2.2 



8.8 



1.7 



1.9 



1.1 



1.0 



0.32 



0.78 



3.5 



*> 2 



11.0 

 5.6 

 8.2 

 8.6 

 6.8 

 3.7 

 4.3 

 6.1 



10.2 



9.5 



13.4 



11.9 



20.7 



18.8 



0.79 

 0.48 

 0.92 

 0.65 

 0.66 

 0.38 

 0.44 

 0.77 



0.85 

 0.75 



2.80 

 1.46 

 1.39 

 2.04 



4.7 

 3.7 



0.81 

 0.34 

 0.57 

 0.58 

 0.56 

 0.30 

 0.25 

 0.37 



2/ 



twice that amount. As seen in Table 3 more than ^/^ respectively -/g 

 of the nucleic acid taken up from the circulation by the liver was split 

 in the course of 2 hours. This is clearly a lower limit. The labelled non- 

 acid soluble fraction of the liver, for example, contains not only the 

 nucleic acid taken up from the plasma but also the labelled phosphati- 

 des formed from labelled free phosphate in the liver. At least 4 per cent 



Table 4. — Percentage ^^p Administered as Nucleic 

 Acid Present in 1 gm Fresh Tissue 



