摘要
目的 观察慢性锰中毒大鼠脑5-羟色胺、脑源性营养因子（BDNF）的表达变化.方法 将60只雄性正常SD大鼠按完全随机数字表法分为对照组（n=15）和实验组（n=45）.实验组又分为低锰组（n=15）、中锰组（n=15）、高锰组（n=15）3个亚组,每天分别腹腔注射二氯化锰四水合物5、15、25 mg/kg,每周连续注射5d,持续12周.采用蔗糖水偏好实验、敞箱实验评估大鼠是否具有抑郁样症状,采用电感耦合等离子体-原子发射光谱法测定大鼠纹状体的锰含量,高效液相色谱法测定大鼠额叶皮质、海马的5-羟色胺含量,蛋白质印记法检测大鼠额叶皮质、海马BDNF的表达,并应用实时荧光定量PCR技术检测大鼠额叶皮质、海马BDNF mRNA的相对表达量.结果 蔗糖水偏好实验及敞箱实验结果显示,慢性锰中毒大鼠均出现抑郁样行为,高锰组表现更加明显,差异有统计学意义.与对照组5-羟色胺含量（组织湿重）相比[额叶（459.65±16.81） ng/g、海马（323.92±17.41）ng/g],给锰组大鼠额叶皮质5-羟色胺含量[（423.45±17.19） ng/g、（376.89±18.87） ng/g、（280.17±25.46） ng/g]及海马中的5-羟色胺含量[（265.71±17.89） ng/g、（214.35±23.63） ng/g、（172.67±18.24） ng/g]减少,差异有统计学意义（F=132.68,P＜0.05;F =69.66,P＜0.05）.与对照组相比（额叶0.962±0.111、海马0.873±0.101）,给锰组大鼠BDNF的表达随锰剂量的增加而显著下降,锰浓度越高,BDNF表达水平降低越明显,给锰组各亚组大鼠之间额叶BDNF蛋白表达（0.855±0.106、0.649±0.112、0.506±0.121）、海马BDNF的表达水平（0.731±0.092、0.626±0.104、0.544±0.113）差异有统计学意义（F=13.26、P＜0.05;F=18.54,P＜0.05）.与对照组相比（额叶0.000 87±0.000 07、海马0.00082±0.00009）,给锰组各亚组大鼠额叶BDNF mRNA的相对表达量（0.00071±0.00006、0.000 48±0.000 03、0.00036±0.00003）及海马BDNFmRNA的表达量（0.000 57±0.000 05、0.00049±0.00004、0.00038±0.000 05）随锰剂量增加而减少,差异有统计学意义（F=18.46,P＜0.05;F=12.76,P＜0.05）.结论 慢性锰中毒大鼠可出现抑郁样行为,锰蓄积可导致额叶及海马神经元内5-羟色胺、BDNF表达量下降.
Objective To observe the expression changes of 5-hydroxytryptamine （5-HT）,brainderived neurotrophic factor （BDNF） in rats with chronic manganism.Methods Sixty healthy male Sprague-Dawley rats were randomly divided into control group （n =15） and experimental group （n =45）.The experimental group was divided into three subgroups：low-dose group （n =15）,middle-dose group （n =15）,high-dose group （n =15）.The rats in control group were given intraperitoneal injection of normal saline while the rats in low-dose group,middle-dose group,high-dose group were given intraperitoneal injection of 5 mg/kg,15 mg/kg and 25 mg/kg manganese chloride tetrahydrate,respectively for 5 days oncea week and lasted for 12 weeks.The depressive behavior changes of rats were observed by sucrose preference test and open field test.The concentrations of manganese in the striatum of rats were detected by inductively coupled plasma-atomic emission spectrometry.The expression of 5-HT in frontal cortex,hippocampus of rats was determined by high performance liquid chromatography.The expression of BDNF in frontal cortex,hippocampus of rats was examined by Western blotting.The expression of BDNF mRNA was detected using real-time fluorescence quantitative polymerase chain reaction.Results The chronic manganese poisoning rats presented depression-like behavior based on the sucrose preference test and open field test,which was more distinct in high-dose rats.As compared with the control group （frontal cortex （459.65 ± 16.81） ng/g,hippocampus （323.92 ± 17.41） ng/g;tissue wet weight）,the expressions of 5-HT were significantly decreased in frontal cortex （（423.45 ± 17.19） ng/g,（376.89 ± 18.87） ng/g,（280.17 ± 25.46） ng/g）,hippocampus （（265.71 ± 17.89） ng/g,（214.35 ±23.63） ng/g,（172.67 ± 18.24） ng/g） of the experimental group （F =132.68,69.66,both P 〈 0.05）.As compared with the control group （frontal cortex 0.962 ±0.111,hippocampus 0.873 ± 0.101;the expressions of BDNF were significantly decreased in frontal cortex （0.855 ± 0.106,0.649 ± 0.112,0.506 ± 0.121） and hippocampus （0.731 ± 0.092,0.626 ±0.104,0.544 ± 0.113） with the increasing concentration of MnCl2 which showed dose dependence （F =13.26,18.54,both P 〈 0.05）.As compared with the control group （frontal cortex 0.000 87 ± 0.000 07,hippocampus 0.000 82 ± 0.000 09）,the expressions of BDNF mRNA were decreased significantly in frontal cortex （0.000 71 ± 0.000 06,0.000 48 ± 0.000 03,0.000 36 ± 0.000 03） and hippocampus （0.000 57 ± 0.000 05,0.000 49 ± 0.000 04,0.000 38 ± 0.000 05） in the treated group with the increasing concentration of manganese （F =18.46,12.76,both P 〈 0.05）.Conclusion Rats with chronic manganese poisoning could present depression-like behavior and the expression of 5-HT and BDNF is decreased in the frontal cortex and hippocampus with the increased accumulation of manganese.
出处
《中华神经科杂志》
CAS
CSCD
北大核心
2015年第6期486-492,共7页
Chinese Journal of Neurology
基金
国家自然科学基金资助项目（81460181）
广西自然科学基金资助项目（桂科自0728147）
广两科学研究与技术开发计划项目（09-090-05）
关键词
锰中毒
5-羟色胺
脑源性神经营养因子
抑郁
Manganese poisoning
5-Hydroxytryptamine
Brain-derived neurotrophic factor
Depression
