456 



ADVENTURES IN RADIOISOTOPE RESEARCH 



32p 



varying between. 1.18 and 2.46. For the ratio of the quotiens — for 



the irritated and non-irritated nerves figures varying between 1.10 and 

 1.98 were obtained. 



Table 3. — Weight of Cat 2.4 kgm Left Nerve Stimi'lated for 5 min. At the 

 End of the Second Mint'te 0.4 Millicurie ^-P Injected Intravenously 



Table 4. — Weight of Cat 1.8 kgm Left Nerve Stimulated for 5 Min. At the 

 End of the Second Minute 0.4 Millicurie ^sp Injected Intravenously. During 

 THE Last Minute Intermittent Stimulation (2.5 Sec. Irritation and 2.5 Sec. Rest) 





ci p.< iS 



tic 



.s S -1" 



Stimulated .... 

 Non-stimulated 



0.137 



0.089 



If we wish to know the percentage of P present in the nerve tissue 

 (cf. above) that was taken up in the course of the experiment, we must 

 compare the specific activity of the nerve P with the average value 

 for the inorganic P of the plasma. This magnitude does not necessarily 

 correspond to the amount that has penetrated from the plasma into the 

 tissue during the experiment, as it is conceivable that a part of the P 

 migrating from the plasma into the tissue cells has found its way back 

 again. Considering that the amount of plasma P located in the nerve 

 tissue constitutes only a small percentage of the total P content of the 

 tissue and in view of the rapid participation of intruded phosphate in 

 phosphorylation processes, we may suppose the amount of labelled P 

 (plasma P) located in the nerve tissue to be practically identical with 

 that penetrating from the plasma into the nerve tissue during the ex- 

 periment. Assuming that the specific activity of the plasma inorganic P 

 of the cat declines after intravenous injection at the same rate as in 



