CHANGE OF GLUTATHIONE S-TRANSFERASES IN THE SKIN BY ULTRAVIOLET-B IRRADIATION

Glutathione S-transferases (GSTs) may play an important role in protec ting skin from ultraviolet radiation (UVR). However, the study on the response of GST to UVR is limited at present. We have examined the eff ects of a single exposure to ultraviolet B (WE) radiation on GST in cu ltured human keratinocytes and the epidermis of SKH/hr-1 hairless mice . We have also investigated the changes of skin GST by chronic irradia tion of WE on the hairless mice. Significant decreases in GST activiti es in vitro and in vivo were observed at 24 h after 30 and 50 mJ/cm(2) UVB irradiation. Chronic UVB exposure also caused decrease in GST act ivities of the skin tissue. However, any changes in mRNA expression or protein amount of GST have not been observed by Northern blot analysi s and Western blot analysis after 30 mJ/cm(2) WE irradiation in cultur ed human keratinocytes, which suggests that mRNA expression and protei n amount of GST are not affected by WE. These results suggest that WE irradiation results in inhibitory effect on GST activity in the skin.