摘要
目的观察慢性氟中毒大鼠大脑胆碱能毒蕈碱受体（muscarinic acetylcholine receptor，mAChR，简称M受体）mRNA和蛋白表达，探讨其在慢性氟中毒性脑损伤及学习记忆能力降低发生机制中的作用。方法选择健康SD大鼠60只，采用随机数字表法按体质量分为2组：对照组和染氟组，每组30只，雌雄各半。对照组大鼠自由饮用自来水（含氟量〈0．5mg／L）；染氟组饮用氟化钠和自来水配制溶液（含氟量为50．0mg／L），2组大鼠均饲以标准饲料（含氟量为6．2mg／kg）。实验10个月后，用Morris水迷宫方法检测大鼠行为学变化（代表学习能力的逃避潜伏期时间和代表记忆能力的空间探索次数）；应用实时荧光定量PCR和蛋白质印迹法检测大鼠大脑组织M受体亚型M1、M3的mRNA及蛋白表达；分析学习记忆能力与M1、M3受体蛋白表达的相关关系。结果染氟组大鼠逃避潜伏期时间[（21．68±2．90）s]较对照组[（6．14±1．71）s]延长（t=0．289，P〈0．05）；空间探索次数[（11．62±2．26）次]较对照组[（19．00±3．69）次]降低（t=0．352，P〈0．05）。染氟组大鼠大脑组织M1、M3受体mRNA表达[（17．07±6．89）％、（12．25±5．03）％]及蛋白表达[（71．07±6．89）％、（32．25±4．66）％]均低于对照组[（100．00±3．00）％、（100．00±2．15）％和（100．00±9．01）％、（100．00±10．33）％，t=0．210、0．157、0．095、0．296，P均〈0．05]。相关分析结果显示，大鼠逃避潜伏期时间与M1、M3蛋白表达呈负相关关系（r=-0．683、-0．700，P均〈0．05），空间探索次数与M1、M3蛋白表达呈正相关关系（r=0．867、0．837，P均〈0．05）。结论慢性氟中毒大鼠大脑组织M受体mRNA及蛋白表达水平降低，可能是氟中毒大鼠学习记忆能力降低的机制之一。
Objective To detect the expression of muscarinic acetylcholine receptors （mAChRs） at mRNA and protein levels in the brain of rats with chronic fluorosis and to reveal the role of the receptors in brain injury and learning and memory deficits. Methods Sixty healthy SD rats were divided into two groups （30 rats in each group, half males and half females） by random number table method according to body weight. In the control group, the rats were fed with drinking water containing no more than 0.5 mg/L fluoride; in the fluoride group, the rats were fed with high doses of sodium fluoride in drinking water （50.0 mg/L）. Each group was fed with normal diet （6.2 mg/kg）. After being exposed to fluoride for 10 months, behavioral performance was measured with Morris water maze, including the escape latency time and the numbers of crossing platforms. After being sacrificed, rat brains were taken and weighted. M1 and M3 subunits at mRNA and protein levels were detected by real-time PCR and Western blotting, respectively; the correlation between protein levels of the receptor subunits and the ability of learning and memory was analyzed. Results In fluoride group, the escape latency time [（21.68±2.90）s] was significantly longer than that of control group [（6.14 ± 1.71）s, t = 0.289, P 〈 0.05]; and the number of crossing platforms [（11.62 ± 2.26） times] was significantly decreased as compared to that of control group [（19.00 ± 3.69）times, t = 0.352, P 〈 0.05]. Furthermore, the mRNA expression [（17.07 ± 6.89）%, （12.25 ± 5.03）%] and the protein levels [（71.07 ± 6.89）%, （32.25 ± 4.66）%] of M1 and M3 receptors in rat brains were significantly lower as compared to those of controls[（100.00 ± 3.00）%, （100.00 ± 2.15）% and （100.00 ± 9.01）%, （100.00 ± 10.33）%, t = 0.210, 0.157, 0.095, 0.296, all P 〈 0.05]. The escape latency and M1, M3 protein levels were negatively correlated （r = - 0.683, - 0.700, all P 〈 0.05）, and the number of space exploration and M1, M3 protein levels were positively correlated （r = 0.867, 0.837, all P 〈 0.05）. Conclusion Declined expression of mAChRs at mRNA and protein levels have been detected in the brain of rats with chronic fluorosis, which may be one of the main mechanism concerning the learning and memory deficits
出处
《中华地方病学杂志》
CAS
CSCD
北大核心
2015年第2期84-88,共5页
Chinese Journal of Endemiology
基金
国家自然科学基金（81160335）
科技部国际合作重大项目（2013BAl05803、2010DFB30530）
贵州省科技厅国际合作项目（黔科合外G字[2011]7014号）.
关键词
氟
脑
胆碱能毒蕈碱受体
学习
记忆
Fluorine
Brain
Muscarinic acetylcholine receptors
Learning
Memory
