[en] Skin wounding at 24 h before whole-body ⁶⁰Co irradiation of mice raised the LDsub(50/30) from 8.09 to 9.71 Gy resulting in a dose reduction factor of 1.2. Concentrations and quantities of myeloproliferative cells were examined at 3, 7, 10, and 14 days after 7 Gy, skin wounding 24 h before 7 Gy and in control non-treated mice. Wounding before irradiation provoked an increase in marrow and splenic clonogenic cells that was earlier and greater than that noted for irradiated mice. Supranormal levels of splenic CFU-s and CFU-c were found in animals wounded before irradiation. M-CFC values were depressed throughout, although greater for combined injured animals than for irradiated mice. (Auth.)