Post-irradiation diethyldithiocarbamate-inhibition of CuZn superoxide dismutase reduces clonogenic survival of Chinese hamster V-79 cells.

The survival of Chinese hamster cells was reduced when they were temporarily treated with diethyldithiocarbamate (DDTC), an efficient inhibitor of CuZn superoxide dismutase (SOD), before radiation exposure. The dose-modifying factor amounted to about 1.3, and was the same for irradiation under hypoxic and aerobic conditions. Treatment of the cells with DDTC in the early post-irradiation hours was, however, equally effective. The results suggest that inhibition of CuZn SOD does not enhance the immediate radiation damage, but increases damage in the first hours of the post-irradiation period, possibly through mechanisms interfering with potential lethal damage.