The Effect of Depolymerized Deoxyribonucleic Acid and Deoxyribonucleotides on the Survival of X-Irradiated Mammalian Cells in Culture

Abstract

To establish a possible restorative effect of depolymerized DNA and deoxyribonucleotides, a number of experiments were designed. The ability of L-cells to form visible colonies after X-irradiation was used as the criterion of survival. Compounds to be tested were added to the growth medium immediately after the cells had been irradiated with 500 R. The addition of enzymatically hydrolyzed DNA as well as of 4 deoxyribonucleotides displayed a restorative effect which did not differ from that obtained with highly polymerized isologous DNA. The addition of a single deoxyribonucleotide did not produce any significant restorative effect irrespective of its concentration. These results suggest that the restoration of radiation damage in these cells could occur by influencing some metabolic pathways involved in the synthesis of nucleic acids.