EFFECT OF X-RAYS ON NUCLEIC ACID IN JENSEN-SARCOMA 



707 



the former is not negligible. The same is true of the speed of replacement 

 of intracellular phosphate by plasma (lymphatic) phosphate. The exchange 

 equilibrium in necrotic tissue has not proceeded as far as in the fresh 

 tissue; in the course of 2 hr, however, a considerable portion of the 

 free sarcoma phosphate is replaced by plasma phosphate. Hence it follows 

 that a good circulation of blood (lymph) must exist in part of the necrotic 

 tissue. The intrinsically decreased rate of formation of nucleic acid in 

 necrotic tissue is reduced still further by the action of the X-rays. 



Pcrcenlagr of injected ^^P present in 1 mgm 



Table 9. — Nucleic Acid Synthesis in Sarcomas Irradiated at 80 r/min 



FOR 25 min 



49 : 1 



49 : 2 



49 : 3 



49 : 4 



50 : 1 



50 : 2 



50 : 3 



Mean vahie 



45^ 



