电离辐射所致细胞死亡的主要形式为细胞凋亡。细胞凋亡的基因调控机制精密而复杂 ,P53、bcl- 2家族、Fas系统、c- myc、P34 cdc2、caspases等均参与辐射性细胞凋亡的调控。细胞凋亡是细胞内一系列凋亡蛋白酶激活的级联反应和细胞表面死亡接受外部信号调节的结果。辐射性细胞凋亡的滞后期因细胞种类而异 ,线性能量传递 ( L ET)及辐射剂量影响细胞凋亡率 The main form of cell death caused by ionizing radiation is apoptosis. The mechanism of gene regulation of apoptosis is sophisticated and complex. P53, bcl-2 family, Fas system, c-myc, P34 cdc2 and caspases all participate in the regulation of radiation-induced apoptosis. Apoptosis is the result of a cascade of caspase-activated cascades and cell surface death undergoing external signal modulation in the cell. The lag phase of radiation-induced apoptosis varies with the cell type, and linear energy transfer (L ET) and radiation dose affect the rate of apoptosis