中等剂量(20Gy)电离辐射后海马神经元的基因表达及尼莫地平的干预作用

MEDIUM-DOSE(20Gy)IONIZING RADIATION ON THE EXPRESSION IN THE HIPPOCAMPUS AND MEDITATIVE EFFECT OF NIMODIPINE

目的通过研究电离辐射后海马神经元的反应、以及尼莫地平的干预作用,为放射性脑病的治疗、电离辐射的防护提供实验依据。方法小鼠全脑电离辐射(DT20Gy)模型,应用免疫组织化学和半定量分析方法,观察 Pax-6、Fos 及 NOS 阳性细胞在海马的分布与变化情况。结果与对照组相比,单纯照射组电离辐射后海马齿状回 Pax-6阳性神经元明显减少,尼莫地平(Nimodipine)药物干预后较对照组 Pax-6阳性细胞数进一步下调;c-fos 在电离辐射后2d 时上调;7d 时有所下降,且药物干预后 c-fos 表达较单纯照射组上升更显著,同样7d 时 c-fos 表达下降;NOS 阳性细胞电离辐射后上调,2d 较7d 时高,药物干预后 NOS 阳性细胞数较对照有所下降;统计学处理上述变化具有显著性意义。结论结果提示:动物接受中等剂量电离辐射后海马神元有明显的功能变化(抑制)或损伤反应,早期应用 Nimodipine 处理对电离辐射可能具有一定干预作用。

Objective To examine hippocampus neurons in response to ionizing radiation and mediation of nimodipine,and in order to provide experimental evidence for the treatment of radiation brain diseases and prevention of ionizing radiation. Methods The whole-brain radiation animal moders,immunhistochemistry and semi-quantification analysis were tuilized,and distribution patterns and dynamic changes of Pax-6 Fos and nitric oxides synthase (NOS)-immunorective neurons were observed in the hippocampus regions.Result Compared with controls,expression of Pax-6 in hippocampusl dentate gyrus neurons decreased markedly following radiation,and more evidently by admimistration of nimodipine;the expression of Fos protein in hippocampus also went up distinctly 48 hours after radiation,they went down 7 days after radiationin,and more evidently by adminstation of nimodipine;whereas NOS-positive neurons went down and Compared with controls;Significant differences were confirmed by statistics analysis.Conclusions Present results have suggested that obvious functional changes or injury neuronal response occurred in the hippocampus system of animals receiving ionizing radiation,and early administation of nimodipine showed mediatation effect on the neuronal response to ionizing radiation.