The role of intracellar glutathione (GSH) in radiation protection has been noticed in recent years. In this study

we found that the level of intracellar glutathione and radiosensitization had a certain relationship. It was recognized that the higher GSH level

the lower radiosensitization. The GSH level in V 79-379 A

Y 79

SPC-A-1

SGC-7901 and So-Rb 50 cells were showed in this experiment

s by Tietze method. The GSH level which was depleted by BSO was assessed. The radiosensitization was determined by the standard colony formation assay

IN VITRO

. The results showed that SER (Sensitization Enhancement Ratio) for V 79-379 A cell was increased with GSH depletion. The SER for BSO 0.1

0.5 and 1.0 mmol/L were 1.16

1.34 and 1.50

respectively. Same results for Y 79 cells were also observed that the SER for BSO 0.01 and 0.05 mmol/L were 1.21 and 1.36 respedively. On the other hand

the exposure time of BSO also influenced GSH level and SER. These results suggested that the level of glutathione in cell and radiosensitization has a close relationship.