中文摘要：

目的 研究地塞米松（DEX）诱导小鼠胸腺细胞凋亡进程中线粒体去极化作用特点。方法 无菌获取Balb／e小鼠胸腺细胞，设对照组和DEX组；在5h时点，利用Annexin V-FITC/PI双染流式细胞术检测细胞凋亡；利用DiOC6（3）／PI双染流式细胞术检测细胞线粒体去极化与死亡；利用CiOC6（3）／Annexin V-PE双染流式细胞术检测凋亡过程中的去极化现象。结果 在1×10^-6 mol／L DEX诱导下，小鼠胸腺细胞在5h凋亡百分率为（36．20±5．11）％，对照组为（4．10±0．98）％，差异显著（P〈0．01）；DEX组坏死百分率为（4．07±0．24）％，对照组为（1．25±0．25）％，差异显著（P〈0．01）。DEX组线粒体去极化增强仍存活的细胞所占百分率为（46．77±6．21）％，显著高于对照组的（12．80±4．55）％（P〈0．01）。DEX组线粒体去极化增强且已启动凋亡的细胞为（35．34±4．19）％，显著高于对照组的（7．21±0．61）％（P〈0．01）。DEX组线粒体去极化作用增强未凋亡的细胞为（13．68±1．27）%，显著高于对照组的（6．85±0．92）％（P〈0．01）。结论 DEX诱导小鼠胸腺细胞发生典型细胞凋亡和线粒体去极化增强，在该进程中，线粒体去极化增强发生在细胞膜磷脂酰丝氨酸外翻之前。

英文摘要：

Objective To study on the dexamethasone （DEX）-induced mitochondrial depolarization and apoptosis process in mouse thymocyte. Mehtods The thymocytes of Balb/c mouse was acquired sterilely, and then divided into control group and DEX （ 1 × 10^-6 mol/L） group. At time point of 5 h, the apoptotic and necrotic cells were examined by Annexin V-FITC/PI double staining flowcytometry; the depolarization and cell mortality were determined by DiOC6（3 ）/PI double staining floweytometry; the depolarization during apoptosis process was tested by DiOC6 （3） Annexin V-PE double staining flowcytometry. Results At the time point of 5 h, the apoptotic rate of mouse thymocyte in DEX goup was （36.20±5.11）%, which was significantly higher than that [（4.10±0.98）%] of control group （ P 〈 0.01） ; the rate of depolarized cells in DEX group [（46.77±6.21）%] was significantly higher than that [（12.80±4.55）%] of control group （P 〈 0.01）; the depolarized and apoptotic thymocyte rate in DEX group [ （35.34 ± 4.19）% ] was significantly higher than that [ （7.21 ± 0.61 ）% ] of control group （P 〈 0.01）. The rotes of depolarized but non-apoptotic thymocyte in the two groups had similar trend, which were （13.68±1.27）% and （6.85 ± 0.92） %, respectively （ P 〈 0.01 ）. Conclusion DEX can induce typical apoptosis and mitochondrial depolarization of thymocytes, and the mitochondrial depolarization occurs before exposure of membrane phosphatidyl serine.