EFFECT OF IONIZING RADIATION ON THE CELL CYCLE PROGRESSION OF BONE MARROW HEMATOPOITIC CELLS IN MICE

The changes of cell cycle progression in drice bone marrow hemopoietic cell and the dose-effect celationship after X-ray whole body irradiation (WBI) were studed by flow cytometry (FCM) The data showed the elevation of the percentage of cells in G1 phase 12h after irradiation (p 0.05), the decrease of cells in S phase 4h (p 0.05) and the increase of cells in G2+M phase 4h and 12h after 2.0Gy WBI. 12h after 0.5~6.0Gy irradiation the percentage of cells in G1 phase became higher than that of sham-irradiation, especialy in 1.0, 2.0, 4.0 and 6.0Gy groups (p 0.05 ~ p 0.01), both the decrease of S phase percentage (p 0.05 ~ p 0.01)and the increase of G2+M phase (p 0.05 ~ p0.001) were in a dose-dependent manner. Ourresults suggested that 2.0Cy X-ray WBI to mice might lnduce the arrest in G1 and G2 phase and the suppression of DNA synthesis, these changes were all in dose- dependent manner within 0.5~6.0Gy.