受照射的淋巴细胞死亡过程中,核结构的瓦解与DNA碎片一起出现。有人认为,照射小鼠胸腺和脾中参与形成脱氧核糖多核苷酸(DPN)的酶是碱性核酸内切酶,它的最适pH是8.0。肝是具有放射抗性的器官,在全身照射后只能从肝提取出来少量的DPN。然而,肝中依赖于Ca~(2+)/Mg~(2+)的核酸内切酶的作用位点规则地沿着染色体亚结构排列 During the death of irradiated lymphocytes, disruption of the nuclear structure occurs with DNA fragments. It is thought that the enzyme involved in the formation of deoxyribonucleoside (DPN) in mouse thymus and spleen is alkaline endonuclease and its optimum pH is 8.0. The liver is a radioresistant organ that has only a small amount of DPN extracted from the liver after systemic irradiation. However, the role of the Ca ~ (2 +) / Mg ~ (2+) -containing endonuclease in the liver is regularly arranged along the chromosomal substructure