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目的 观察高氧环境下不同肺细胞的形态和功能改变.方法 体外分离培养18 d胎鼠的Ⅱ型肺泡上皮细胞(AECⅡ)和肺成纤维细胞(LFs),并将其分为空气组(置于常氧培养箱,氧体积分数0.21培养)和高氧组(置于高氧培养小室,氧体积分数0.90培养).镜下观察两种细胞的形态学改变;通过划痕实验观察细胞迁移情况;用流式细胞仪检测细胞内活性氧(ROS)水平及细胞凋亡情况.结果 高氧培养8 h,镜下观察AECⅡ细胞体积增大,排列疏松;LFs细胞间隙增大,排列杂乱.划痕实验显示,与空气组比较,高氧处理6 h即可抑制AECⅡ细胞的迁移能力〔细胞迁移度:(38.67±1.15)％比(58.67±2.31)％,P<0.01〕,12 h即可促进LFs细胞的迁移〔细胞迁移度:(55.37±1.50)％比(46.90±1.20)％,P<0.01〕.随高氧时间延长,AECⅡ、LFs细胞内ROS含量均逐渐增加,12 h时已显著高于空气组(荧光强度:130.67±4.04比54.67±2.51,85.00±2.00比60.33±1.52,均P<0.01).两种细胞均在高氧暴露后出现凋亡,暴露2 h时AECⅡ凋亡细胞率即较空气组明显增高〔(1.93±0.28)％比(1.07±0.11)％,P<0.05〕,暴露6 h时LFs凋亡细胞率即较空气组明显增高〔(1.66±0.09)％比(1.46±0.09)％,P<0.05〕.结论 高氧可引起肺细胞生长不良,使AECⅡ迁移水平降低而LFs迁移增加,肺细胞内ROS大量生成,最终引起肺细胞大量凋亡.

Objective To observe the morphological and functional changes of different lung cells in hyperoxia environment.Methods Type Ⅱ alveolar epithelial cells (AECⅡ) and lung fibroblasts (LFs) of fetal rats with 18 days old were isolated and culturedin vitro, and divided into air group (placed in an atmospheric incubator, and culturing with oxygen volume fraction of 0.21) and hyperoxia group (placed in a high oxygen culture chamber, and culturing with oxygen volume fraction of 0.90). Morphological changes of two kinds of cells were observed under microscope. Cell migration was observed by scratch test. The levels of reactive oxygen species (ROS) and apoptosis in cells were detected by flow cytometry.Results After 8 hours of hyperoxia, the volume of AECⅡincreased and the cells were loosely arranged; the clearance of LFs cells was increased and arranged in disorder. Scratch test showed that, compared with air group, the immigration rate of AECⅡ was inhibited at 6 hours hyperoxia [migration rate: (38.67±1.15)％ vs. (58.67±2.31)％,P < 0.01], the immigration rate of LFs was promoted at 12 hours after hyperoxia [migration rate:(55.37±1.50)％ vs. (46.90±1.20)％,P < 0.01]. With the increase of hyperoxia time, intracellular ROS contents of two cells were gradually increased, which were significantly higher than those of the air group (fluorescence intensity:130.67±4.04 vs. 54.67±2.51, 85.00±2.00 vs. 60.33±1.52, bothP < 0.01). Both two kinds of cells showed apoptosis after exposure to high oxygen, the apoptosis rate of AECⅡ at 2 hour exposure were significantly higher than that of air group [(1.93±0.28)％ vs. (1.07±0.11)％,P < 0.05], the apoptosis rate of LFs at 6 hour exposure was significantly higher than that of air group [(1.66±0.09)％ vs. (1.46±0.09)％,P < 0.05].Conclusion High concentration of oxygen can cause poor growth of lung cells, reduce AEC Ⅱ migration level and increase LFs migration, and the production of intracellular ROS eventually leads to apoptosis of lung cells.