摘要
目的探讨低剂量重金属镉、汞单独及等浓度联合作用对人胚肝细胞（L02）生长的兴奋效应及可能的机制。方法以体外培养的L0：细胞为实验对象，不同浓度的镉、汞单独及等浓度（0．01—100μmol／L）联合处理L0：24h后，用Vi—CELLTMXR活力分析仪分析细胞生长状况；根据Finney数学模型和Logistic回归方法判断联合作用类型；按照二硫代二硝基苯甲酸比色法和黄嘌呤氧化酶法测定谷胱甘肽过氧化物酶（GSH—Px）与超氧化物歧化酶（SOD）的活力；依据ParvinderKaur的检测方法检测细胞内ROS水平；火焰原子吸收光谱法及原子荧光法分别检测细胞内镉、汞吸收量。结果低剂量的镉、汞（0．01、0．05、0．25μmol／L）单独染毒及镉＋汞（0．01，0．05μmol／L）联合染毒处理24h能明显刺激LO2细胞生长；Finney数学模型显示镉、汞等浓度联合作用于LO2细胞24h后Q=1．9，说明其联合作用属于相加作用；低剂量的镉、汞单独及联合染毒LO2细胞24h均能明显诱导SOD与GSH—Px活力升高，当剂量增大到一定水平（25．6μmol／L）后又抑制两种酶活力。细胞内ROS水平与重金属吸收量随染毒剂量增加而增加。结论低浓度重金属镉、汞单独及等浓度联合作用对LO2生长存在Honnesis效应，其机制可能是低浓度镉、汞诱导细胞GSH—Px、SOD活力增强，清除过量的自由基，保护细胞免受氧化损伤，提高细胞存活率。
Objective To understand the hormetic effects of low dose of cadmium, mercury alone or in combination on LO2 cells and the mechanism. Methods Human embryo liver LO2 cells were exposed to different concentration of cadmium （II＇）, mercury （II） alone or in combination for 24 hours. The survival rate of LO2 cells was measured by Vi-CELLTM XR Viability Analyzer;, the activity of SOD and GSH-Px were measured by corresponding testing cassette; the level of ROS was measured according to Parvinder Kaur＇s methods; the heavy metal uptake was measured by atomic absorption spectroscopy and atomic fluorescence spectroscopy. Results After exposure to low doses of mercury（0.01, 0.05 and 0.25 μmol/L）, cadmium （0.01, 0.05, 0.25 μmol/L） and cadmium＋mercury（0.01, 0.05 μmol/L） for 24 hours, the growth of LO2 cells was significantly stimulated. The results got from Finney model showed that the joint toxicity was simple additive effect when LO2 cells exposed to cadmium＋mercury. The activity of GSH-Px and SOD were increased when exposed to low close of cadmium and mercury alone or in combination, but it was inhibited when the concentration came up to 25.6 μmol/L. The level of intracellular ROS and heavy metal uptake were increased with the increasing of heavy metal. Conclusion Exposed to low concentration of cadmium, mercury alone or in combination may significantly stimulate the growth of LO2 cells, the possible mechanisms may be that low concentrations of cadmium and mercury can enhance the activity of GSH-Px and SOD to scavenge free radicals and protect cells from oxidative damage.
出处
《环境与健康杂志》
CAS
CSCD
北大核心
2012年第1期16-19,共4页
Journal of Environment and Health
基金
中央高校基本科研业务费专项资金资助(HUST:2011QN204)
