THE INFLUENCE OF RADIATION ON THE 

 METABOLISM OF ASCITES TUMOUR CELLS* 



Arne Forssberg 



Institute of Radiophysics , Stockholm 



For some years we have been concerned with studies on 

 effects of X-rays on Ehrhch ascites tumours. Some of that 

 work is inchided in the present survey. 



When an intraperitoneally growing Ehrhch ascites tumour 

 in a stage of rapid growth is irradiated in vivo with a dose of 

 1250 r, comparatively moderate cell lesions arise (Klein and 

 forssberg, 1954). From analyses during a 48-hour observa- 

 tion period following that dose it appears that the number of 

 tumour cells is not significantly increased nor does the per- 

 centage of non-tumourous exudate cells increase. The first 

 property is due to the fact that cell division is completely 

 inhibited and that the slow reappearance of mitotic activity 

 which occurs some 20 hours after irradiation does not ap- 

 preciably increase the total number of tumour cells in the 

 sample. The second property is at variance with the findings 

 when doses of the order of LD50 or thereabouts are adminis- 

 tered. A relative increase in exudate cells is inter alia pro- 

 voked by the presence of disintegrating tumour cells. The 

 constant cellular composition of the sample is a prerequisite 

 for the present series of investigations because it enables 

 biochemical studies to be made on a cell population at various 

 times in the interval 0-48 hours after irradiation, under well 

 defined conditions. Furthermore, judging from the method of 

 supravital staining as well as from biochemical properties, 

 irradiation does not significantly increase the number of dead 

 cells. Although the cellular composition is fairly constant, 

 cytological changes do occur. Mitosis disappears during the 



* Review based on work in co-operation with Drs. G. Klein and L. R6vesz, 

 Institute of Cell Research, Karolinska Institutet, Stockholm. 



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