Wortmannin, a radiation sensitizer, enhances the radiosensitivity of WKAH rat cells but not that of LEC rat cells

No significant cytotoxic effect was observed in WKAH rat cells by the treat ment of wortmannin, a radiation sensitizer, at concentrations lower than 30 mu M for 24 hr. The relative surviving fractions of LEC rat cells were sli ghtly, but significantly, lower than those of WKAH rat cells at each concen tration of wortmannin. When the wortmannin-treated WKAH rat cells were X-ir radiated, the relative surviving fractions decreased in a wortmannin concen tration-dependent manner. On the contrary, no significant difference was ob served between the survival curves of untreated and wortmannin-treated LEC rat cells after X-irradiation.