摘要Objective:The aim of the study was to investigate the adaptive response of low-dose radiation-induced apoptosis in mouse spleen cells and its related proteins control mechanism.Methods:Kunming male mice were randomly divided into sham-irradiation group,attacking dose irradiation group (D2) and low-dose radiation+attacking dose irradiation group (D1+D2).After a week the D1+D2 group was given low-dose radiation (doses were 25,50,75 and 100 mGy,dose rate of 12.5 mGy/min),after 6 hours the D2 group and the D1+D2 group were given attacking dose of radiation (Dose of 1.5 Gy,dose rate of 287 mGy/min).After 18 hours all mice were killed.The spleen cell apoptosis and Caspase-3 expression's changes were detected by flow cytometry (FCM) analysis,and the changes of apoptosis-related proteins Bcl-2 and Bax were detected by immunohistochemical staining semi-quantitative method.Results:The rate of apoptosis,the fluorescence intensity of Caspase-3,and the semi-quantitative results of apoptosis-related proteins Bcl-2 and Bax in every group were significantly different.Of all groups,the apoptosis rate and Caspase-3 fluorescence intensity of D2 group were the highest.Compared with the sham-irradiated group,Bcl-2 protein level of D2 group decreased significantly,and Bax protein level of D2 group increased significantly.But compared with D2 group,the apoptosis rates,the fluorescence intensities of Caspase-3 expression and the Bax protein levels in D1+D2 group were lower in different doses,and the Bcl-2 protein levels in D1+D2 group were higher in different doses.Conclusion:25-75 mGy low-dose radiation can induce the adaptive response of mouse spleen cells'apoptosis,the expression of Caspase-3,and the apoptosis-related protein Bcl-2 expression increased,Bax reduced,and it leads to the apoptosis of the spleen cells decreased.