醋酸铅对人肾小管上皮细胞凋亡及超微结构的影响

The toxic effects of lead acetate on the apoptosis and the ultrastructure in human renal tubular epithelial cells （HK-2）

目的探讨醋酸铅对人肾小管上皮细胞（HK-2）凋亡的作用及对超微结构的影响。方法经5、10、20μmol／L醋酸铅染毒HK-2细胞24h后，Hoehest33342染色法观察细胞形态学变化，透射电子显微镜下观察细胞超微结构的变化，分光光度计检测细胞培养上清中乳酸脱氢酶（LDH）活力、丙二醛（MDA）含量，DNALadder实验检测醋酸铅对HK-2基因组的影响，应用流式细胞仪检测细胞凋亡率。结果Hoehest33342-PI染色显示，染铅组细胞呈凋亡形态学改变。透射电子显微镜下观察发现，染铅组细胞胞质内出现空泡，核固缩，核膜结构模糊，并出现凋亡小体。染铅组细胞培养上清中LDH活力及MDA含量较对照组明显升高，差异有统计学意义（P〈0．01）。HK-2基因结果显示，染铅组出现较为明显的DNA损伤现象。5、10、20μmol／L染铅组细胞凋亡率分别为14．16％±2．94％、19．45％±2．73％、25．01％±3．97％，均明显高于对照组（5．81％±2．18％），差异均有统计学意义（P〈0．05）。结论醋酸铅可促进HK-2细胞凋亡，进而影响肾脏正常功能。

Objective To explore the toxic effects of lead acetate on the apoptosis and uhrastructure of human renal tubular epithelial cells （HK-2）. Methods After HK-2 cells were exposed to 5, 10 and 20 μmol/L lead acetate for 24 h, the morphological changes of HK-2 cells were observed by Hochest 33342-PI staining, and the ultrastructure changes of HK-2 cells were examined under a electron microscope, LDH activity and MDA content in supernatant of HK-2 cellular culture were detected by spectrophotometer, DNA damage of HK-2 was determined by DNA ladder and the apoptotic rates of HK-2 cells were measured by flow cytometry. Results The morphological changes of apoptotic HK-2 cells in exposure group were observed by Hochest 33342-PI staining. The cytoplasm vacuoles, karyopycnosis, nuclear membrane vague and apoptotic bodies in HK-2 cells of exposure group were found under electron microscopy. LDH activity and MDA contents in exposure group increased significantly, as compared to control group （P〈0.01）. The results of DNA Ladder showed that DNA damage of HK-2 cells in exposure group appeared. The apoptotic rates of HK-2 cells exposed to 5, 10, 20 μmol/ L lead acetate were 14.16% ± 2.94%, 19.45% ± 2.73%, 25.01% ± 3.97%, respectively, which were significantly higher than that （5.81%±2.18%） in control group （P〈0.05）. Conclusion Lead acetate could remarkably induce the apoptosis of HK-2 cells and affect the kidney.