Influence of nalidixic acid on killing and mutation of V79 cells exposed to different damaging agents.
The effect of treatment with nalidixic acid, an inhibitor of DNA topoisomerase, after exposure of V79 cells to different DNA-damaging agents on the induction of killing and mutation has been studied. The DNA-damaging agents were ultraviolet light, gamma-rays and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). It was seen that treatment with nalidixic acid potentiated the killing by MNNG and suppressed the induction of mutation. However, it had no influence upon killing and mutation by UV light and gamma-rays. The difference in the observed results could be due to the nature of the damage induced and its repair in relation to the function of topoisomerases.