超顺磁性三氧化二铁纳米粒子对小鼠活动日节律的影响  

The Effect of Superparamagnetic Iron Oxide Nanoparticles on the Circadian Rhythm of Locomotor Activities in Mice.

作　　者：张鹏[1,2] 周岚[1,2] 徐海飞[1,2] 曹济民[1,2] 

机构地区：[1]中国医学科学院基础医学研究所 [2]北京协和医学院基础学院生理学和病理生理学系,北京100005

出　　处：《医学研究杂志》2011年第6期19-23,共5页Journal of Medical Research

基　　金：国家自然科学基金资助项目(81071072);科技部"973"课题资助项目(2011CB933504)

摘　　要：目的研究进入脑室的超顺磁性铁纳米粒子（SPION）是否对小鼠活动的昼夜节律有影响。方法选6周龄的C57BL／6J小鼠，人工光照环境光照：黑暗=12：12（光照：8：00—20：00；黑暗：20：00～次日8：00）。自由摄食饮水。待动物完全适应新环境（约2周）后，将动物转入全黑暗环境继续饲养14天，然后开始转轮实验。选择CT（circadian time）14时间点，侧脑室注射三氧化二铁纳米粒子（SPION）4μl；对照组侧脑室注射不含SPION的溶剂（超纯水）4μl。注射后继续转轮实验若干时间。分别在侧脑室注射10min、24h、14天和30天后处死动物，并取脑组织做石蜡切片，经普鲁士蓝染色观察SPION在脑室内的分布情况。用VitalView动物行为节律记录仪连续监测小鼠转轮运动节律的变化情况。用realtime—RT—qPCR检测钟基因的变化。结果侧脑室注射SPION 10min和24h后，SPION仅分布于脑室壁上，神经细胞内未见染色。注射SPION14天、尤其是30天后可见脑内神经细胞有SPION染色。同时，侧脑室注射SPION可引起中枢钟视交叉上核（SCN）的periods钟基因转录上调，小鼠转轮运动日节律向后漂移。结论SPION经侧脑室注射后可进入脑细胞内，影响了SCN钟基因的表达以及运动日节律的改变，提示进入脑内的纳米材料可影响生物节律。Objective To study the effect of superparamagnetic iron oxide nanoparticles （SPION） by intracerebroventricular adiministration on the locomotor circadian rhythm in mice. Methods Six -week -old male C57BL mice were maintained on a 12h light （200lux） - 12h dark cycle for 14 days with free access for food and water, then the animals were put into constant darkness （DD） for another 14 days, followed by the start of running wheel monitoring under DD condition. SPION （4μ1） was intracerebroventricularly injected （ i. c. v. ） at CT （circadian time） 14 and monitoring of the running wheel activitied was continued for different time periods. Animals were sacrificed after 10 min, 24h, 14d, or 30d, respectively. Brain tissues were developed and brain paraffin sections were stained with prussian blue to identify the location of SPION. Clock genes were detected by real time - RT - qPCR. Results Within 24h after SPION in- jection, the SPION were attached to the cerebral ventricle walls, but were not observed inside the neuronal cells. However, SPION were observed entering into the neuronal cells 14d after the injection. In addition, a phase delay of the circadian rhythm of the locomotor activi- ties was observed in the SPION injected group compared with the placebo - injected animals. The locomotor activity of mice circadian rhythm changed. The mRNA levels of perl and per2 in the SCN were significantly elevated in the SPION treated animals while unchanged in the control animals. Conclusion SPION can enter into the neuronal cells after i. e. v. administration and affected the circadian rhythm of locomotor activities in mice. These effects are associated with the alterations of the perl and per2 transcriptions in the SCN.

关 键 词：磁性纳米粒子 日节律 钟基因 

分 类 号：R587.102[医药卫生—内分泌]