Effects of Adriamycin on the Radiation Response of Murine Hematopoietic Stem Cells

The effects of adriamycin on radiation response of murine hematopoietic stem cells are studied using the spleen colony technique. Doses of adriamycin causing little cell kill did not affect the radiation survival curve. When dosage sufficient to result in 35% survival (0.8 mg) was given, the shoulder of the radiation survival curve disappeared without any change in the D₀. When tested using divided doses of radiation, repair was not inhibited. Further, the trough seen in controls when the two doses of radiation were separated by 8-12 hr was not seen in the adriamycin-treated group. In fact, with these fractionation schemes survival in the presence of the drug was greater than in its absence.