EFFECT OF DIFFERENT DOSES IRRADIATION ON THE CELL CYCLE PROGRESSION OF BONE MARROW CELLS IN MICE

The changes of cell cycle progression in mice bone marrow cells and the dose effect relationship after X ray whole body irradiation (WBI) were studied by flow cytometry (FCM). The data showed no significant change in cell cycle progression after WBI with 0.075 Gy X rays;the elevation of the percentage of cells in G 1 phase at 12 h(p0.05); the decrease of cells in S phase at 4 h(p0.05) and the increase of cells in G 2+M phase at 4 h and 12 h after WBI with 2.0 Gy. At 12 h following 0.5～6.0 Gy irradiation the percentage of cells in G 1 phase became higher than of sham irradiation; especially in 1.0,2.0,4.0 and 6.0 Gy groups (p0.05~ 0.01); both the decrease of S phase percentage (p0.05~0.01) and the increase of G 2+M phase (p0.05~0.01) were in a dose dependent manner. Our results suggested that 0.075 Gy X rays had little effect on the cell cycle progression;while 2.0 Gy X ray might induce the arrest in G 1 and G 2 phase and the suppression of DNA synthesis;these changes were all in dose dependent manner within 0.5～6.0 Gy.(