百草枯致体外培养人胚肺成纤维细胞凋亡及氧化损伤

Paraquat Induced Apoptosis and Oxidative Damage in Human Embryonic Lung Fibroblast

[目的]观察百草枯(PQ)对体外培养人胚肺成纤维细胞(MRC-5)的毒性作用,并探讨可能的损伤机制。[方法]不同浓度(0.00、0.15、0.30、0.60、1.20、2.40、4.80、9.60mmol/L)PQ处理MRC-5细胞24h后,采用四甲基偶氮唑盐微量酶反应比色法(MTT法)测定MRC-5细胞存活率,流式细胞术检测细胞凋亡情况;同时用分光光度比色法测不同浓度(0.00、0.15、0.30、0.60、1.20mmol/L)PQ处理3、12、24h后,MRC-5细胞超氧化物歧化酶(SOD)、丙二醛(MDA)含量和细胞上清液中乳酸脱氢酶(LDH)活性。[结果]与对照组相比,PQ≥0.30mmol/L时开始明显抑制细胞生长,并随着染毒浓度的增加细胞存活率明显下降(P<0.05)。与对照组相比,短时间、低剂量(3、12h,0.15mmol/L)作用下,SOD活性下降不明显,其他组别明显下降(P<0.05);与对照组相比,染毒后不同时点MDA含量均较自身对照上升,LDH含量较对照上升(除染毒3h,1.20mmol/L组),且差异有统计学意义(P<0.05或P<0.01);0.60、1.20mmol/L组PQ染毒后MRC-5细胞凋亡率明显上升(P<0.05)。[结论]PQ对MRC-5细胞活性的影响存在剂量依赖性,并可影响MRC-5细胞的抗氧化酶活性和细胞凋亡。

[ Objective ] To investigate the toxicity and potential mechanisms of paraquat （ PQ ）-induced human embryonic lung fibroblast （ MRC-5 ）injury. [ Methods ] The changes of cell viability rates were monitored by the methyl thiazolyl tetrazolium （MTT）method after the MRC-5 cell lines were incubated with PQ（ 0.00, 0.15, 0.30, 0.6.0, 1.20, 2.40, 4.80, and 9.60mmol/L ） for 24h, and the cell apoptosis was detected by flow cytometry. Meanwhile, both the total activity of superoxide dismutase（ SOD ） and volume of malondialdehyde （ MDA ）in cell and the activity of lactate dehydrogenase （ LDH ）in the supernatant were detected by spectrophotometry after the MRC-5 cell lines were incubated with PQ（ 0.00, 0.15, 0.30, 0.60, and 1.20mmol/L ） for 3, 12, and 24h, respectively. [ Results ] Compared with the control group, the cell viability rates were inhibited significantly in the groups of PQ 1〉 0.30 mmol/L. With the increased concentration of PQ, the cell viability rates decreased accordingly（ P 〈 0.05 ）. Compared with the control group, the total SOD activity decreased significantly in PQ-treated group（ except 0.15 mmol/L at 3, 12 h ）, MDA and LDH（ except the 3 h, 1.20mmol/L group ）level increased with the positive difference at an interval of 3, 12h and 24 h（ P〈0.05 or P〈0.01 ）. Apoptosis rates of MRC-5 increased significantly after exposuring to PQ on concentration 0.60 mmol/L and 1.20mmol/L. [ Conclusion ] PQ contributes a dose-dependent relationship on MRC-5 cell activity, furthermore, it can affect the MRC-5 cells on the antioxidant enzyme activity and apoptosis.