【摘要】 选近交系615小鼠,以⁶⁰Coγ射线1.7Gy×4,间隔6d的全身照射,剂量率0.26Gy/min。辐射诱发了小鼠胸腺淋巴细胞瘤和白血病,发生率66.3％,检出肿瘤最早时间在照后86d,最密集时间为120～180d。小鼠受照后1～195d的16个时间点动态观察显示历经辐射损伤,修复增生,癌前和癌灶4个阶段。电镜下看到病毒样颗粒。染色体畸变以相互易位为主,并有异常克隆形成。更多还原

【Abstract】 The role of radiation on carcnogenesis and the biological character over the process are reported. 450 inbred mice were exposed to fractionated doses of 60Co r-rays(1.7 Gy weekly and an accumulated dose of 6.8 Gy). Mice were sacrificed at various time during 1-195 days after irradiation. Some changes in histopatho-logy, cytogenctics,ultrastructure and hematology were observed. The results indicated that radiation induced thymoma in treated mice(66.3%), nonc occurred in control. Under histopathological and ultrastructural studies, 4 steps appeared clearly after irradiation were noticed: thymic cortex atrophy, hyperplasia, preca-ncerous and canccrous lesions. Some round viruslike particles could be seen in lymphoma cells of exposed mice. The most frequent type of chromosomal aberration was reciprocal translocation, and the abnormal clones appeared in some cells of thymus, spleen and bone marrow in exposed mice. But there was no significant difference on the frepuency of SCE between two groups. The radiation induced mutation in the target cells may be responsible for the development of tumor and leukemia in an irradiated subject.更多还原