Effects of low-dose hydrogen peroxide treatment of V79 cells on killing and mutation by different agents.

Benzamide (BA) prevented the induction of repair resulting from a small dose of H2O2 pretreatment of V79 cells. Such pretreatment with H2O2 increased the mutation yield by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or gamma-rays, indicating the error proneness of the induced repair activity. Cycloheximide or BA could suppress the increase in the mutation yield. This induced repair function had no effect on the lesions by ultraviolet light and persisted for about 20 h after which it declined.