补骨脂素加长波紫外线光化学疗法对K562细胞凋亡及线粒体膜电位的影响

目的：研究补骨脂素（psoralen，PSO}加长波紫外线（ultraviolet—A，UVA）光化学疗法（PUVA）对人白血病细胞K562凋亡及线粒体膜电位的影响。方法：K562细胞与不同浓度PSO，接受或不接受UVA照射后共同培养，透射电子显微镜下观察细胞超微结构改变，流式细胞仪检测细胞凋亡率和线粒体膜电位变化，采用多因素方差分析法进行统计学处理。结果：PUVA处理后的K562细胞超微结构出现明显的凋亡形态学改变。PSO、UVA照射及PUVA均可使细胞凋亡率增加，线粒体膜电位下降；PUVA的作用显著强于前两者（P〈0．01）。结论：PUVA可诱导白血病K562细胞发生凋亡，诱导凋亡途径之一为下调线粒体膜电位水平。

Effects of psoralen with long wave ultraviolet light on apoptosis and mitochondrial membrane potential in K562 cells

Objective： To study the effects of psoralen （PSO） with long wave ultraviolet light （PUVA） on apoptosis and mitochondrial membrane potential in K562 cells. Methods： K562 cells were incubated with PSO in different concentrations （10, 20, 40 and 80 ug/ml for 24 hours） and irradiated without or with UVA （5 min）. The changes in ultrastructure of the cells were observed under a transmission electron microscope. The apoptosis rates and the changes of mitochondrial membrane potentials were detected by flow cytometry. The factorial design and analysis of variance were used to analyze the interaction among the factors. Results. There were obvious ultrastructure changes related to apoptosis in K562 cells after being treated with PUVA （80 ffg/ml）. PSO, UVA and PUVA all increased the apoptosis rates and decreased the mitochondrial membrane potentials, and the effects of PUVA were stronger than those of PSO and UVA （ P〈0.01）. Conclusion： PUVA can induce the apoptosis of K562 cells and one of the pathways to the induction of apoptosis is to down-regulate the mitochondrial membrane potentials.