中文摘要：

目的探讨热应激对小鼠胸腺细胞凋亡及细胞周期情况的影响。方法1月龄雄性小鼠随机分为6组（A～F），每组5只，A为对照组，B～F为实验组。对照组不进行热应激处理，实验组热应激（37℃）处理2h后恢复室温饲养，于恢复室温后0、2、6、10、20h依次取每组小鼠的胸腺。透射电子显微镜观察细胞形态的变化；流式细胞术、苏木素-伊红（HE）染色分析热应激后不同时间点小鼠胸腺细胞的凋亡及细胞周期情况；免疫组织化学染色检测各时间点小鼠胸腺细胞增殖细胞核抗原（PCNA）和热休克蛋白70（HSP70）的表达情况。结果热应激后2～10h电镜观察均可见典型的凋亡细胞形态；热应激后6h，胸腺细胞的凋亡率及s期细胞数量达到最高，而G0／G1、G2／M期细胞均降至最低，此时间点PCNA表达量较高。HSP70在热应激结束后Oh即开始表达，2～6h表达量最高。结论热应激能够诱导小鼠胸腺细胞的凋亡，而HSP70则在凋亡过程中发挥保护作用。

英文摘要：

Objective To study the effect of hyperthermia to apoptosis on mice thymocytes. Methods One- month-old male mice were divided into 6 groups randomly （A-F）. 5 mice per group, and 1 control group （A） and 5 experimental groups （B-F）. Mice in experimental groups were stressed for 2 hours at 37℃ and then raised at room temperature （RT）. At the different time points （ 0hour,2hours, 6hours, 10hours, 20hours） after RT recovering, thymuses from one group were collected. Transmission electron microscopy was used to observe cellular morphology. Flow cytometry and hematoxylin-eosin （HE） staining were used to analyze apoptosis and cell cycle of thymocytes. Expression of proliferating cell nuclear antigen（PCNA） and heat shock protein（HSPT0） were detected by immunohistochemistry. Results Typical morphology of apoptotic cells were observed under transmission electron microscopy at 2hours, 6hours and 10hours after hyperthermia. At 6hours after hyperthermia, thymocytes of S phase and apoptosis reached the max while thymocytes of G0/G1 phase and G2/M phase reduced to the minimum. At the same time point, PCNA expressed most. But HSP70 began to express at 0hours and expressed most at 2-6hours after hyperthermia. Conclusion Apoptosis of thymocytes was obviously effected by hyperthermia. HSP70 had protective effect during apoptosis.