镉对体外培养大鼠肾小管上皮细胞的毒性损伤及乙酰半胱氨酸的保护效应

在建立肾小管上皮细胞体外培养模型的基础上,通过在培养液中添加不同浓度的醋酸镉和乙酰半胱氨酸(NAC),用CCK-8法测定细胞存活率,流式细胞仪检测细胞凋亡、细胞内活性氧与线粒体膜电位,探讨了镉对体外培养大鼠肾小管上皮细胞的毒性损伤及NAC的保护效应。结果显示,作用12 h,各染毒组与对照组相比,细胞存活率和线粒体膜电位显著下降(P0.05或P0.01),细胞凋亡率、坏死率、乳酸脱氢酶(LDH)漏出率和细胞内活性氧含量均显著升高(P0.05或P0.01),呈剂量-效应关系;而NAC保护组与染毒组相比,细胞存活率和细胞凋亡率均有显著差异(P0.05),细胞坏死率无明显差异(P0.05)。结果表明,本试验所选择的镉浓度引起的肾小管上皮细胞死亡是以凋亡为主,氧化应激直接参与镉对肾小管上皮细胞的毒性损伤,NAC对肾小管上皮细胞凋亡有一定的保护效应。

Toxic effect of cadmium on the primary cultures of rat proximal tubular cells and protective effect of N-acetyl-L-cysteine

The primary cultures of rat proximal tubular cells were treated with different doses of cadmium acetate and/or N-acetyl-L-cysteine (NAC) to investigate the toxic effect of cadmium on these cells and the protective effect of NAC. Cell survival was detected by using the CCK-8 reduction method and the apoptosis,intracellular reactive ox-ygen species (ROS) levels and the mitochondrial membrane potential (Aψ) were assessed by flow cytometer. After treated with cadmium and/or NAC for 12 hours,the cell survival rates and mitochondrial membrane potential(Aψ) in the cadmium exposed groups were significantly lower than those of control group (P<0.05 or P<0.01). Com-pared to the control group, the release rate of LDH and the ROS levels in the cadmium groups were significantly in-creased (P<0.05 or P<0.01) ,displaying a dose-dependent manner. Also,a progressive loss in cell viability togeth-er with a significant increase in the number of apoptotic and necrotic cells were seen in this experiment, while the cel-lular death and the apoptosis could be markedly reversed by NAC. In summary, the apoptosis of rat proximal tubular cells may be mediated by oxidative stress,and NAC has a protective effect on the toxic damage induced by cadmium.