Flow cytometric analysis of thymocyte subpopulations in mice after whole-body X-irradiation

To determined the cellular kinetics of thymocyte subpopulations in DBA1 mic e after whole-body 6.8 Gy X-irradiation, they were analyzed for the express ion of several cell surface antigens using flow cytometry. The results show that i) The majority of thymocytes rapidly depleted by irradiation was CD4 (+)8(+) cells. ii) radioresistant CD4(+)8(-) and CD4(-)8(+) survived 18-48 hr after X-irradiation were considered to be relatively mature type, since they expressed high levels of CD3 and LECAM-1. iii) CD3-positive cells were detected in CD4(-)8(-) cells at 72 hr after irradiation.