RENEWAL OFACIDSOLIBLK PlIOSl'lIOIUS COMPOUNDS I.\ OIUJAXSOK RABBIT 378 



organ and plasma the average specific activity of the cellular inorganic 

 P during the experiment. From the latter magnitude and the specific 

 activity of the P of the organic phosphorus fraction at the end of the 

 experiment, we can calculate what percentage of the organic compound 

 in question is newly formed during the experiment, if only the extent 

 of new formation is restricted. 



If a large fraction of the hexosemonophosphate molecules, for example, 

 is newly formed during the experiment, we can no longer disregard the 

 number of hexosemonophosphate molecules which were decomposed 

 and resynthesized more than once during the experiment. If such a repeat- 

 ed new-formation takes place, it will have the effect that the active 

 hexosemonophosphate molecules present at the end of the experiment 

 cannot be longer considered as having been formed with participation 

 of inorganic P which had an activity corresponding to the average acti- 

 vity prevailing during the experiment. The inorganic P atoms, which 

 had an activity corresponding to a late stage of the experiment, will 



Table 4. — Specific Activity of Acid Soluble P Fractions 

 Extracted from the Organs of the Rabbit 



Rabbit VIII. Weight 2.0 kgm 

 Subcutaneous injection during 9 days 



Fraction 



Specific activity 



at the end of the 



experiment 



Plasma inorganic P 



Corpuscle total acid soluble P 

 Muscle inorganic -j- creatine P 



Muscle ester P 



Brain inorganic -j- creatine P . 

 Brain ester P 



100 

 94 

 40 

 18.7 

 18.8 

 17.3 



Table 5. — Specific Activity of Acid Soluble P Fractions 

 Extracted from the Organs of the Rabbit 



Rabbit IX. Weight 2.5 kgm 

 Subcutaneous injection during 50 days 



Fraction 



Specific activity 



at the end of the 



experiment 



Plasma inorganic P 



Corpuscle total acid soluble P 

 Muscle inorganic -(- creatine P 



Muscle ester P 



Brain inorganic -|- creatine P . 

 Brain ester P 



100 



100 

 88 

 77 

 56 

 68 



