中子和γ射线照射对小鼠骨髓造血细胞死亡方式的探讨(英文)

Different death mode of hematopoictic cells induced by neutron and γ-ray

为探讨中子和γ射线照射后小鼠骨髓造血细胞的死亡方式及其意义,采用不同剂量中子和60Coγ射线全身照射350只BALB/c小鼠,通过光镜、电镜、流式细胞术、原位末端标记和DNA凝胶电泳等观察造血细胞凋亡与坏死情况。研究发现,中子照射后小鼠骨髓中坏死和凋亡的造血细胞均明显增多,5.5Gy组以坏死为主,而γ射线照射后则以凋亡为主,且呈剂量相关性。凋亡的细胞表现为核染色质浓缩、边移,呈半月型、环状或不规则状,凋亡小体形成,电泳下见DNA梯状图谱。坏死的细胞表现为核肿胀、溶解,线粒体膜、核膜等膜性结构破坏。2.5～5.5Gy中子及5.5～12Gyγ射线照射可使骨髓造血细胞死亡方式不同:中子照射以凋亡与坏死并存,5.5Gy组以坏死为主;而γ射线照射则以凋亡为主。

In order to investigate the death mode of hematopoictic cells in mouse bone marrow irradiated by neutron and γ-rays, 350 BALB/C mice, which were whole body irradiated with varies doses of neutron and γ-rays, were sacrificed at 6 and 12hours, 1, 2, 3, 4, 5, 7, 10, 14, 21 and 28days after irradiation respectively. By means of light microscope, electron microscope, flow cytometry, in situ terminal end labeling and DAN gel electrophoresis, the apoptosis and necrosis of hematopoiefic cells were investigated. The results showed that the amount of hematopoiefic cells occurring apoptosis and necrosis were obviously increased after neutron irradiation and the necrosis was main death mode in irradiation dose of 5.5Gy. Meanwhile, γ-irradiation mainly induced apoptosis of hematopoietic cells and the apoptosis was correlated to the irradiation dose. It means that there were different death modes of hematopoietic cells in mouse bone marrow irradiated by neutron and γ-rays. Neutron mainly induced necrosis of the hematopoietic cells though apoptosis also occurred in irradiation dose of 5.5Gy, while γ-rays mainly induced the apoptosis.