中文摘要：

目的：观察不同浓度的氯化钴（CoCl2）对肾上腺嗜铬细胞瘤（PC12）分化细胞增殖与凋亡的影响，探讨合理的体外化学模拟缺氧模式。方法应用不同浓度CoCl2作用于PC12分化细胞不同时间，建立化学性缺氧诱导细胞凋亡的实验模型；将PC12细胞分为空白对照组、不同浓度不同时间的CoCl2处理组；应用细胞计数、MTT、Hoechst33342/PI双染色法检测不同浓度CoCl2对PC12分化细胞的增殖与凋亡的影响。结果①CoCl2（≤200μmol/L）在6h内使PC12细胞存活率轻度增加，12h后开始出现细胞存活率降低，并呈现比较明显的剂量和时间依赖关系；CoCl2（≥300μmol/L）诱导PC12分化细胞6h即开始出现存活率降低（P＜0．01）；②150μmol/L CoCl2诱导PC12分化细胞24h后细胞数量明显减少（P＜0．01）；③通过荧光显微镜可见150μmol/L CoCl2诱导PC12分化细胞24h内受损细胞多为早期凋亡，48h后开始出现晚期凋亡和坏死细胞增多。结论 CoCl2对PC12分化细胞增殖与凋亡的影响呈时间和浓度依赖性，进行化学模拟缺氧要考虑CoCl2的作用浓度和作用时间。

英文摘要：

Objective To investigate the effect of cobalt chloride（CoCl2） of different concentration on differentiated PC12 cells proliferation and apoptosis ,to explore the reasonable strategy of chemical hypoxia induced by CoCl 2 .Methods The hypoxia model was set up by using different concentration of cobalt CoCl 2 to affect differentiated PC12 cells line at different times;PC12 cells were divided into control group and CoCl 2 group;The PC12 cells viability and toxicity were measured by cell counting and MTT assay and Hoechst 33342/PI double staining.Results ①Differentiated PC12 cells viability was weakly increased in low concentration （200μmol/L） of CoCl2 within 6h and began to decreased after 12h.However,higher dose or prolonged challenge of CoCl 2 significantly decreased cell survival rate .But differentiated PC12 cells viability began to decrease in high concentration （300μmol/L） of CoCl2 within 6h（P〈0.01）.②Cell counting showed that the number of PC12 cells was significantly decreased after 24h（P〈0.01）.③Most of the injured cells were showed early apoptisis after the treatment by 150μmol/L CoCl2 within 24h,but showed late apoptisis and necrosis after 48h.Conclusion The apoptotic and proliferative effect of cobalt chloride of different concentration on differentiated PC 12 cells is dose and time dependent .The concentration and duration of CoCl 2 ad-ministration should be taken into consideration in chemical hypoxia .