围生期甲状腺功能减退对幼鼠海马神经元结构及功能的影响  

Effect of perinatal hypothyroidism on hippocampal neuronal structure and function of neonatal rats

作　　者：曹银利[1] 高俊[1] 唐成和[1] 郭洪旭[1] 

机构地区：[1]河南省新乡医学院第一附属医院新生儿科,新乡453100

出　　处：《中华神经医学杂志》2016年第10期979-983,共5页Chinese Journal of Neuromedicine

摘　　要：目的探讨围生期甲状腺功能减退（PHT）对新生幼鼠大脑海马神经元结构及功能的影响。方法16只SD孕鼠按照随机数字表法分为对照组和PHT组，每组8只。自孕15d起每日分别给予生理盐水（对照组1或6-丙基-2-硫尿嘧啶（PTU）灌胃（PHT组）至幼鼠出生并持续整个哺乳期，复制PHT动物模型。幼鼠出生第7日起每组取15只行酶联免疫吸附法（ELISA）测定血清游离三碘甲状腺原氨酸（FT31、游离四碘甲状腺原氨酸（FT4）及促甲状腺激素（TSH）值以及海马组织中乙酰胆碱（Ach）含量。实时定量PCR及Western blotting分析海马组织神经元核抗原（NeuN）和轴突标志物微管相关蛋白tau（MAPT）mRNA及蛋白表达水平。免疫组化染色实验观察PHT对幼鼠海马组织中NeuN和MAPT表达的影响。剩余幼鼠生长至1月龄时行水迷宫实验评价其学习记忆能力。结果（1）和对照组相比，PHT组幼鼠血清FT3、FT4值显著降低，TSH含量升高；海马组织中Ach含量降低约3倍，差异均有统计学意义（P〈0．05）。（2）PHT组幼鼠海马NeuN和MAPTmRNA表达水平显著降低，表达量分别为对照组的0．25和0．12倍；蛋白表达量也仅为对照组均值的0.35和0．22倍，差异均有统计学意义（P〈0．05）。（3）免疫组化染色结果提示PHT组幼鼠海马组织中NeuN及MAPT的表达水平均存在不同程度的降低。（4）水迷宫实验中PHT组1月龄大鼠逃避潜伏期和总距离分别为（24．36±5．15）s、（790．36±72．53）cm，显著高于对照组[（10．18±3．02）s、（365．28±41．77）cm]，差异均有统计学意义（P〈0．05）。结论围生期甲状腺激素缺乏可导致幼鼠大脑海马神经元标志物表达降低，轴突功能异常以及神经递质释放减少，幼鼠远期学习记忆能力显著减弱。Objective To study the effect of perinatal hypothyroidism （PHT） on hippocampal neuronal structure and function of neonatal rats. Methods Sixteen pregnant SD rats were randomly divided into control group and PHT group （n=8）. The pregnant rats were subjected to gavage by normal saline or 6-propyl-2-thiouracil （PTU） every day from 15 d of pregnant to the end of lactation. After parturition, 38 male neonatal rats from each group were chosen for the following study. On the 7th d of birth, 15 neonatal rats from each group were sacrificed, and the concentrations of free triiodothyronine （FT） 3, FT4 and thyroid stimulating hormone （TSH） in serum and acetylcholine （Ach） in the hippocampus were detected by ELISA. Real-time PCR, Western blotting and immunohistochemistry were used to assess the expressions of neuronal nuclei antigen （NeuN） and microtubule-associated protein tau （MAPT） in transcriptional and protein levels orderly. The left neonatal rats at one month old were performed morris water maze test to evaluate the learning and memory abilities. Results ELISA results showed that both FT3 and FT4 significantly decreased but TSH increased significantly in serum of PHT rats as compared with those in the control group （P〈0.05）; Ach in the hippocampus of PHT rats was reduced three folds as compared with those in control group, with significant difference （P〈0.05）. Real-time PCR and Western blotting results showed that the mRNA and protein expression levels of NeuN and MAPT in PHT rats were markedly down-regulated as compared with those in the control group： 0.25 and 0.12 fold ofmRNA level in control group, and 0.35 and 0.22 fold of protein level in control group, with significant differences （P〈0.05）. Immunohistochemistry indicated decreased NeuN and MAPT expression levels of varying degrees in PHT rats. In the morris water maze, on Perinatal hypothyroidism; Neuron; Learning and memory ability; Hippocampuse-month-old rats with PHT showed significantly prolonged escape la

关 键 词：围生期甲状腺功能减退 神经元 学习记忆 海马 

分 类 号：R722[医药卫生—儿科]