Studies on the effect of x-rays on the biochemistry and cellular composition of ascites tumors. I. Effect on growth rate, cell volume, nucleic acid and nitrogen content in the Ehrlich ascites tumor
Klein, G.; Forssberg, A.
Experimental Cell Research 6(1): 211-220
ISSN/ISBN: 0014-4827 PMID: 13141999 DOI: 10.1016/0014-4827(54)90163-9
The Ehrlich mouse ascites tumor was irradiated in vivo with 1250 r X-rays. This dose inhibited mitosis completely for about 15 hours but did not increase the death rate, as judged by supravital staining. A linear increase of average cell volume against time followed the treatment and resulted in a doubling of size in about 48 hours. Both nucleus and cytoplasm contributed to this increase. The rate of cellular enlargement was approximately equal to the growth rate of the cell population before irradiation, the difference being that growth after irradiation occurred mainly as increase in size of the individual cells, while in the untreated population it is solely due to cell multiplication. After irradiation, the average amount of Pna and total nitrogen per cell increased at nearly the same rate as cell volume, i. e. their cellular concentration remained about the same. In contrast, the amount of Dna showed only a very slight increase, resulting in a decrease of cellular concentration of this compound. This indicates a specific action of irradiation on the synthesis of DNA.