Relationship between intracellular GSH levels and hypoxic cell radiosensitivity

The present studies show the following: (a) The plating density of cells (V79 and GM3877) affects the experimentally determined OER values. (b) Fibroblasts depleted of cysteine and GSH are more sensitive to radiation under hypoxic conditions (under aerobic conditions the absence of cysteine or GSH has no detectable effect on radiation sensitivity). (c) Addition of GEE to V79 cells (previously depleted of GSH) leads to increased intracellular GSH levels and protects the cells against radiation under hypoxic conditions.