The effect of vitamin E on cellular survival after X irradiation of lymphoma cells

Asynchronous cultures of a lymphocytic mouse leukaemic cell line L5178Y were X-irradiated under oxic and hypoxic conditions. The survival curves had almost no shoulder when the cells were grown under normal conditions and then irradiated in the presence of vitamin E, whereas a clear shoulder appeared when the cells were grown and irradiated in a medium supplemented with vitamin E (100 μg/ml). There was no change in the final sensitivity to lethal events in the vitamin E enriched cells. The results suggest that the radioprotective effect of vitamin E depends on its incorporation into the cell membranes. (U.K.)