放射性核素137Cs、90Sr对半滑舌鳎肝脏细胞氧化应激毒性的研究

Oxidative stress toxicity effects of radioactive nuclide 137Cs、90Sr on liver cells of Cynoglossus Semilaevis

以半滑舌鳎肝脏细胞(HTLC)为研究对象,利用噻唑蓝比色法(MTT)、乳酸脱氢酶(LDH)、活性氧自由基(ROS)和超氧化物歧化酶(SOD)等方法分析细胞活性、细胞膜完整程度以及氧化应激反应相关指标,探究海洋环境中放射性核素137Cs、90Sr的生物毒性效应。HTLC细胞活性随137Cs、90Sr活度升高呈先增加后降低的趋势,且在低活度核素作用下,细胞活性增加极其显著(p<0.01),137Cs对细胞膜无损伤,90Sr则使细胞膜损伤显著(p<0.05),但二者均能使ROS含量和SOD活性显著性增加(p<0.05)。高活度核素作用下SOD活性均显著增加(p<0.05),但137Cs作用时ROS无显著变化,90Sr则使ROS显著增加(p<0.05)。研究表明,在本实验活度条件下,137Cs和90Sr对海洋鱼类细胞无显著的生物毒性,细胞能够通过自我调节维持正常功能。90Sr能产生氧化应激反应,对膜系统造成损伤,可能影响细胞多种代谢途径,对生物体具有潜在的毒性效应。

To analyze the biotoxicity of radioactive nuclide 137Cs and 90Sr,liver cells of cynoglossus semilaevis(HTLC) were exposed to DMEM-F12 with a series of concentrations of 137Cs and 90Sr,respectively.MTT assay was used to evaluate the cytotoxicity of 137Cs and 90Sr.Lactate dehydrogenase(LDH),reactive oxygen species(ROS) and superoxide dismutase(SOD) activity were applied to explore the oxidative damage of 137Cs and 90Sr on HTLC.The results indicated that cell activity was significantly promoted by both 137Cs and 90Sr,especially under their low concentration(p<0.01),but the promotion was increased first and decreased later with the increase of 137Cs and 90Sr.The cell membrane was damaged significantly only with low concentration of 90Sr(p<0.05),while 137Cs made no damage on HTLC cell membrane.ROS contents displayed significant difference at the lower 137Cs concentration and all the 90Sr exposure groups(p<0.05),whereas SOD activity displayed significant difference in all 137Cs and 90Sr exposure groups(p<0.05).The results confirmed that 137Cs and 90Sr was not significantly toxic to HTLC in the environmental activity,and HTLC was able to adjust itself to maintain normal physiological function.However,90Sr can induce oxidative stress in HTLC and damage cell membrane,which may affect the metabolic pathways and lead to potential toxicity in HTLC.