乙酰半胱氨酸及德巴金预处理后氯化亚铁对皮层神经元膜电位及过氧化物的影响

目的探讨和观察N-乙酰半胱氨酸（NAC）及德巴金（DP）预处理后氯化亚铁（FeCl2）对皮层神经元膜电位及过氧化物的影响。方法培养的新生SD大鼠皮层神经元细胞分为，5组：对照组（PBS）、模型（FeCl2）组、NAC预处理组、DP预处理组、NAC＋DP预处理组。采用反映细胞膜电位和过氧化物水平荧光强度的荧光探剂DiBAC4（3）和乙酰乙酸盐2’,7’二氯氢化荧光素（H2 DCF）分别标记，应用激光共聚焦扫描显微镜动态观察各组神经元细胞相对荧光强度变化。免疫组织化学检测NF-κB的表达情况。结果与对照组比较，模型组反映过氧化物的荧光强度增强（P〈0．05）；与模型组比较，NAC组及NAC＋DP组荧光强度降低（P〈0．01），而DP组变化不明显（P〉0．05）。与模型组比较，DP组及NAC＋DP组可抑制神经元受FeCl2作用后膜电位变化，该两组荧光强度降低（P〈0．01）；而NAC组变化不明显（P〉0．05）。模型组较对照组NF-κB染色强度明显增加，NAC组与NAC＋DP组较模型组染色强度明显降低。结论FeCl2对皮层神经元的作用可导致过氧化物的生成，NAC预保护可减少神经元受FeCl2作用后过氧化物等自由基的生成，DP可起到稳定神经元受FeCl2作用后膜电位的作用，两者共同预处理可显著减轻神经元受FeCl2作用的损伤。抗氧化剂联合抗癫痫药可能有助于防治与铁剂诱发有关的癫痫发作。

Effect of N-acetyl-cysteine and depakine pretreatment on ferrous chloride-induced membrane potential and peroxidate changes in rat cortex neurons

OBJECTIVE: To investigate the effect of N-acetyl-cysteine (NAC) and depakine (DP) on the changes of membrane potential and peroxidate in rat cortex neurons exposed to ferrous chloride (FeCl(2)). METHODS: Cultured cortex neurons of newly born SD rats were randomly divided into control group (PBS group), model group (FeCl(2) group), NAC pretreatment group (NAC group), DP pretreatment group (DP group) and NAC+DP pretreatment group (NAC+DP group). In the latter three groups, NAC (0.08 mg/ml) and DP (0.1 mg/ml) were added in the cell culture 2 and 3 h before FeCl(2) (1 mmol/L) exposure, respectively. After exposure to FeCl(2), the membrane potential of the neurons was detected with fluorescent dye DiBAC4(3) (bis-(1,3-dibutylbarbituric acid) trimethine oxonol), and the peroxidate level with 2,7-dichlorofluorescin diacetate (H(2)DCF) by laser confocal scanning microscope (LCSM) and nuclear factor-KappaB (NF-KappaB) level with immunocytochemistry. RESULTS: Compared with FeCl(2) group, the expression of NF-KappaB and peroxidate level in the neurons were decreased significantly in NAC and NAC+DP groups (P<0.01), but not in DP group (P>0.05). FeCl(2) depolarized the membrane potential and increased the expression of NF-KappaB in the neurons. Compared with FeCl(2) group, significant changes in the membrane potential were observed in DP and NAC+DP groups (P<0.01) but not in NAC or PBS group (P>0.05). CONCLUSION: Both NAC and DP can protect the neurons from FeCl(2)-induced damage but through different pathways, and their combined use can significantly alleviate neuronal damages due to FeCl(2) exposure. Antioxidants such as NAC in combination with antiepileptic drugs may produce favorable effect in prevention and treatment of posttraumatic epilepsy.