褪黑素对缺氧状态下N2A细胞的抗氧化应激作用及机制研究

摘要

目的探究褪黑素（MT）对缺氧状态下小鼠神经母细胞瘤（N2A）细胞超氧化物歧化酶（SOD）、氧自由基（ROS）、丙二醛（ MDA）含量变化的影响。方法取原代培养的小鼠神经母细胞瘤细胞随机分为对照组、缺氧组、MT治疗组，治疗组以5μg／mL的褪黑素工作液孵育24 h建立治疗模型。除对照组外的细胞培养箱中通入95％N2＋5％CO2的混合气体，在低浓度血清中培养24 h，使细胞处于氧胁迫状态，建立N2A细胞缺血缺氧模型。采用黄嘌呤氧化法、荧光定量检测法及硫代巴比妥酸比色法检测N2A细胞内SOD、ROS、MDA含量变化。结果与对照组相比，缺氧组与MT治疗组的SOD表达量均有明显降低，差异具有统计学意义（P＜0．05）；MT治疗组与缺氧组相比细胞SOD表达量有显著恢复，差异具有统计学意义（P＜0．05）。与对照组相比缺氧组与MT治疗组的ROS、MDA表达量均有明显升高（P＜0．05），MT治疗组与缺氧组相比细胞ROS、MDA表达量有显著恢复，差异具有统计学意义（P＜0．05）。结论褪黑素对继发性缺血缺氧神经细胞损伤具有保护作用，其机制可能与褪黑素通过直接清除细胞内的自由基或者上调细胞内抗氧化物的表达水平相关。%Objective To investigate the effects of melatonin on the changes of superoxide dismutase ( SOD ) , reactive oxygen species (ROS),and malondialdehyde(MDA) in N2A cells under hypoxia conditions.Methods Randomly divided the primary cultured neuroblasto-ma cells of mouse into the control group ,hypoxia group ,and MT treatment group .The MT treatment group were given melatonin 5μg/mL for 24 h to set up the treatment model .Rsbiotech of the hypoxia group and MT treatment group were given gaseous mixture of 95%N2 and 5%CO2 ,The ischemia hypoxia model of N 2A cells was set up with cells in the oxidative stress state and cultured for 24 hours at low concentra-tions of serum .The content of SOD , ROS, and MDA was measured respectively by xanthine oxidase , fluorogenic quantitative detection and thiobarbituric acid chromatometry .Results The expression of SOD in hypoxia group and MT treatment group were significantly decreased compared with that in control group(P<0.05).The level of SOD in MT treatment group significantly recovered compared with hypoxia group with singnificant difference (P<0.05).The expression of MDA and ROS in hypoxia group and MT treatment group were significantly in-creased compared with that in control group (P<0.05).The level of MDA and ROS in MT treatment group significantly recovered compared with hypoxia group with singnificant difference (P<0.05).Conclsion Melatonin provides a protective effect on the secondary damage of nerve cells with hypoxia ischemia .The possible mechanism is melatonin could play the role of free radical scavenging and up -regulate the ex-pression level of antioxidants .