摘要 : Investigation of the radiation-induced bystander effect plays an important role in theunderstanding of the mechanisms of radiation response after low-dose irradiation.Sphingomyelinase (SMase) was activated by radiation and require... 展开 Investigation of the radiation-induced bystander effect plays an important role in theunderstanding of the mechanisms of radiation response after low-dose irradiation.Sphingomyelinase (SMase) was activated by radiation and required the metal elementfor its activation. For further elucidation of the bystander effect, we investigated therelationship between its induction by acid SMase and a factor secreted from theirradiated tumor cells. In the cell culture medium transfer experiment after irradiation ata dose of 0.1 Gy, cell death was induced in non-irradiated cells. However, when cellsreceived prior treatment with SMase inhibitor, cell death was not induced. Whenfluctuations in the activation of SMase and metal elements were detected, bothintracellularly and extracellularly after irradiation, an increase in SMase activity and Znconcentration occurred within the cells at 5 min and outside of the cells at 15 min afterirradiation. This increase in zinc concentration at 15 min after irradiation wassuppressed by treatment with SMase inhibitor. These results suggest that activation ofSMase, which is related to the bystander effect, is dependent on zinc. 收起