锰对小鼠黑质多巴胺转运体和受体表达影响的研究  

Study on effect of manganese on the expression of dopamine transporter and receptors expression in the substantia nigra of mice

作　　者：邓宇[1] 王飞[1] 徐斌[1] 刘巍[1] 李乐慧[1] 奉姝[1] 

机构地区：[1]中国医科大学公共卫生学院环境卫生学教研室,辽宁沈阳110001

出　　处：《实用预防医学》2014年第3期257-260,共4页Practical Preventive Medicine

基　　金：国家自然科学基金项目(编号81302406);教育部高等学校博士学科点专项科研基金联合资助课题新教师类(编号20112104120017)

摘　　要：目的 研究锰对小鼠黑质多巴胺转运体（DAT）和多巴胺受体（DRD1和DRD2）表达的影响,为锰中毒机制的研究提供理论依据. 方法 昆明小鼠40只,按体重随机分成4组,每组10只.第1～4组分别为对照、低锰、中锰、高锰组,4组小鼠依次腹腔注射0.9％ NaCl、12.5、25和50 mg/kg MnCl2,注射容量均为5ml/kg,染毒2周.ELISA检测黑质内多巴胺（DA）含量,免疫组化法检测酪氨酸羟化酶（TH）表达,Western blotting检测DAT、DRD1和DRD2的蛋白水平. 结果 染锰2周后,随着染锰剂量的增加,上述指标均逐渐下降并呈现一定的剂量依赖性.与对照组相比,在低、中、高锰组中,DRD2的蛋白水平均明显降低（P＜0.05;P＜0.01; P＜0.01）;在中、高锰组中,DA含量和TH阳性表达均显著降低;而DAT和DRD1蛋白水平仅在高锰组中均明显下降（P＜0.01;P＜0.05）. 结论 锰可能通过下调DAT、DRD1和DRD2,造成黑质多巴胺能神经元减少,DA含量降低,导致多巴胺能神经系统损伤.Objectives To study the effect of manganese （Mn） on the expression of doparnine transporter （DAT） and dopamine receptors （DRD1 and DRD2） in the substantia nigra of mice,and to provide theoretical evidence for studying the pathogenesis of manganese poisoning.Methods Forty Kunming mice were randomly divided into control group,low-,medium-and high-Mn groups （each n=10）,which were respectively given intraperitoneal injections of 0.9% NaCl,12.5 mg/kg,25 rng/ kg,and 50 mg/kg MnCl2 in a volurnn of 5ml/kg for 2 weeks.Dopamine （DA） levels in the substantia nigra were determined by ELISA kits.The expression of tyrosine hydroxylase （TH） was observed by immunohistochemistry method.Protein levels of DAT,DRD1 and DRD2 were determined by Western blotting.Results With the elevation of MnCl2 concentrations,DA,TH,DAT,DRD1 and DRD2 were all gradually reduced in a dose-dependent manner after Mn exposure for 2 weeks.Protein levels of DRD2 were decreased significantly in low-,medium-,and high-Mn groups （P 〈 0.05 ; P 〈 0.01 ; P 〈 0.01） compared to control group.DA levels and TH positive expression in medium-and high-Mn groups were both significantly inhibited,but DAT and DRD1 protein levels were down-regulated only in high-Mn group （P 〈 0.01 ; P 〈 0.05）.Conclusions Mn induces the damage of dopaminergic system in the substantia nigra of mice,which possibly results from down-regulation of DAT,DRD1 and DRD2,loss of dopaminergic neurons,and DA depletion.

关 键 词：锰 黑质 多巴胺 酪氨酸羟化酶 多巴胺转运体 多巴胺受体 

分 类 号：R-332[医药卫生]