中文摘要：

目的 探讨AT细胞高辐射敏感性与细胞凋亡之间的联系。方法 以液体闪烁测量法测3H-TdR掺入百分率来观察^60Co γ射线照射对AT5BIVA（AT）和GM0639（GM）细胞增殖的影响;实验于照射后0、24、48和72 h,用细胞流式术动态检测AT和GM细胞的自发凋亡率及^60Co γ射线照射诱发的凋亡率。结果 ^60Co γ射线0～6 Gy照射后,AT和GM两种细胞3H-TdR掺入百分率均呈剂量依赖性降低,且AT细胞降低得比GM细胞快,两种细胞3H-TdR掺入百分率与受照射剂量间可拟合成指数方程：SAT=0.9718e^-0.6855D（R^2=0.9950）、SGM=1.0928e^-0.3731D（R^2=0.9777）;AT细胞的自发凋亡率高于GM细胞;2～6 Gy照后24 h,两种细胞由辐射诱发的凋亡率均随照射剂量增大而升高,且在同一剂量点,前者凋亡率高于后者;2 Gy照射后0～72 h,AT和GM细胞的凋亡率均呈时间依赖性增加,且随照后时间延长两者间差异逐步增大,在72 h达到显著水平。结论 AT细胞高辐射敏感性与其较高的自发及辐射诱发的凋亡密切相关。

英文摘要：

Objective To explore the relationship between the high radiosensitivity of AT5BIVA fibroblast line and apoptosis. Methods AT5BIVA（AT） fibroblasts and GM0639（GM） fibroblasts were exposed to O-6 Gy ^60Co γ-rays. The effects of ^60Co γ-ray irradiation on the proliferation of AT and GM fibroblasts, expressed by percentage of ^3 H-TdR incorporation in DNA, were measured by liquid scintillation counter. The spontaneous and radiation-induced apoptosis rates were determined by flow cytometry at 0, 24, 48, and 72 h after exposure to ^60 Co γ-rays. Results The percentage of s H-TdR incorporation in DNA in AT and GM fibroblasts decreased with radiation dose, and the s H-TdR incorporation in AT fibroblasts decreased more quickly than that in GM fibroblasts. The relationships between S H-TdR incorporation rate and dose were fitted as SAT = 0.9718e^-0.6855D（R^2 = 0.9950） and SGM = 1.0928e^-0.3731D （R^2 = 0.9777） for AT and GM fibroblasts, respectively. The spontaneous apoptosis rate in AT fibroblasts was higher than that in GM fibroblasts; the radiation-induced apoptosis rate in AT and GM fibroblasts gradually increased with dose at 24th hour after exposure to 2-6 Gy ^60Co γ-rays, and radiation-induced apoptosis rate in the former was higher than that in the latter; the apoptosis rate in both AT and GM fibroblasts showed time-dependent increase during 0-72nd hour after exposure to 2 Gy ^60 Co γ-rays; the difference of the apoptosis rates between AT and GM fibroblasts gradually enlarged with dose and reached a significant level at 72nd hours after the exposure Conclusion The high radiosensitivity of AT fibroblasts was closely related to its spontaneous and radiation-induced apoptosis.