Paraquat Induced Radiosensitization of Mammalian Cells

The potential of paraquat, a dipyridilium compound, to sensitize cells to X-irradiation was examined in hamster lung V79 cells. Paraquat, toxic in its own right to aerobic cells, acts as a radiosensitizer of cells irradiated towards the end of an exposure to nontoxic concentrations of the drug. In combination with radiation, sublethal doses of paraquat, given for two hours prior to irradiation, enhance the lethal effects of radiation by a factor of 1.6 compared to cells exposed to radiation and drug separately. Paraquat has been shown to have a special affinity to lung tissue and may prove useful as an adjunct in radio therapeutic treatment of primary and metastasized tumor sites.