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目的 探讨细胞凋亡在小鼠胸腺淋巴细胞辐射损伤中的作用 ,为阐明淋巴细胞辐射损伤特点和机理以及急性放射病的防治提供重要依据。方法 应用原位末端标记、DNA电泳和免疫组化技术观察经 2、4、6和 8Gy不同剂量γ 线整体照射后 ,小鼠胸腺淋巴细胞凋亡的动态变化过程和Bax、Bcl 2蛋白在其中的作用。结果 (1)照射后早期淋巴细胞凋亡率迅速增加 ,如 6Gy照后 4h和 1天凋亡率分别为对照值的 3 6和 9 3倍 ;凋亡率还还随照射剂量的增加而迅速升高。 (2 )胸腺和外周血淋巴细胞数在照射后急剧减少 ,与淋巴细胞凋亡成相反趋势 ,提示凋亡可能是急性照射后淋巴细胞减少的主要途径之一。 (3)透射电镜观察表明 ,6Gyγ 线照射后 ,小鼠胸腺淋巴细胞出现早、中、晚期典型凋亡细胞的形态学特征。 (4)DNA凝胶电泳显示 2～ 6Gy照后 4和 8h ,胸腺淋巴细胞出现特征的DNA梯形谱。 (5 )照射后Bax、Bcl 2蛋白的异常表达证实二者在淋巴细胞凋亡的调控中起重要作用。结论;;细胞凋亡在不鼠胸腺淋巴细胞辐射损伤全过程中起重要作用;;而Bax和Bcl2蛋白参与了淋巴细胞凋亡的调控。
Objective To investigate the role of apoptosis in the radiation injury of mouse thymus lymphocytes and provide an important basis for elucidating the characteristics and mechanism of lymphocyte radiation injury and preventing and treating acute radiation sickness. Methods The dynamic changes of apoptosis of thymus lymphocytes and the expression of Bcl-2 and Bcl-2 proteins in mice were observed by in situ end-labeling, DNA electrophoresis and immunohistochemistry. Role. Results (1) The rate of early apoptosis of lymphocytes increased rapidly after irradiation. For example, the apoptosis rates at 4h and 1day after 6Gy irradiation were 36 and 93 times of the control respectively. The apoptosis rate also increased rapidly with the increase of irradiation dose Rise. (2) The number of thymus and peripheral blood lymphocytes decreased sharply after irradiation, which was opposite to that of lymphocyte apoptosis, suggesting that apoptosis may be one of the main ways of lymphopenia after acute irradiation. (3) Transmission electron microscopy showed that morphological features of typical apoptotic cells in early, middle and late stages of mouse thymus lymphocytes were observed after 6 Gy line irradiation. (4) DNA ladder gel electrophoresis showed that DNA ladder traits of thymic lymphocytes appeared at 4 and 8 h after 2 ~ 6 Gy irradiation. (5) The abnormal expression of Bax and Bcl 2 protein after irradiation demonstrated that both of them play an important role in the regulation of lymphocyte apoptosis. Conclusion: Apoptosis plays an important role in the whole process of radiation-induced damage of mouse thymus lymphocytes. Bax and Bcl2 proteins are involved in the regulation of lymphocyte apoptosis.