EFFECT OF X-RAYS ON NUCLEIC ACID AND 

 PROTEIN SYNTHESIS IN THE JENSEN RAT 



SARCOMA 



BARBARA E. HOLMES 



This paper describes attempts to detect any metabolic 

 disturbances in tissues, which might result from treatment 

 with ionizing radiations. 



This subject became interesting as soon as it was plain 

 that some specificity of action could be expected. Before the 

 action of radiations on substances in solution and the par- 

 ticipation of the water in this action was partially understood, 

 it was regarded as unlikely that any specificity of action on 

 metabolic processes would be found. 



As soon, however, as attempts were made to show metabolic 

 disturbance as a result of irradiation of tissue with X- and 

 y-rays, it was plain that it was far easier to demonstrate the 

 many systems which were not affected, than to find any 

 which were. The partial inhibition of glycolysis in the retina, 

 found by Crabtree and Gray (1939), is the only case I know 

 of where a clinical dose of irradiation produced an immediate 

 result on the ordinary energy-getting systems of the cell. 



It is, of course, always possible to show metabolic disturb- 

 ances if the tissue is irradiated in vivo and left in the body 

 long enough for death of some of the cells to occur, and such 

 disturbance is sometimes wrongly described as an action on 

 enzymes, when it is actually a change of cell population. Bone 

 marrow irradiated and left in the body for some days has been 

 described in this way as demonstrating enzyme changes, 

 although much destruction of the dividing cells has occurred. 

 Another example is given by rat gut, irradiated in vivo with 

 500 r. X-rays and left for four hours before the killing and 

 dissecting of the animal. Sections taken from the gut at this 

 time show destruction of the considerable masses of lymphoid 



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