[Enhanced lethal effect of combined ACNU with x-ray on cultured HeLaS3 cells].

The combined effects of ACNU and X-irradiation on cultured HeLaS3 cells were investigated. Pretreatment with either ACNU or X-ray induced a substantial reduction in shoulder width the D0 value of the dose-response curve for the other agent, given later was unchanged. ACNU did not inhibit the recovery of sublethal damage (SLD) induced by X-ray when this treatment preceded the split-dose experiment. Our results indicate that some cell damage induced by each agent is transmissible to the progeny of the surviving cells and that the interaction of ACNU and X-irradiation was lethal to the cells.