甲状腺功能减退对成年小鼠空间学习记忆及海马神经颗粒素表达的影响  

Effect of adult-onset hypothyroidism on spatial learning and memory and the expression of neurogranin in the hippocampus

作　　者：曾宪忠[1] 朱德发[1] 陈贵海[2] 杨欣[1] 刘春蕾[1] 

机构地区：[1]安徽医科大学第一附属医院老年内分泌科,合肥230022 [2]安徽医科大学第一附属医院神经内科,合肥230022

出　　处：《中国地方病学杂志》2007年第3期252-255,共4页Chinese Jouranl of Endemiology

基　　金：安徽省自然科学基金（03043708）

摘　　要：目的观察甲状腺功能减退对成年雄性昆明小鼠空间学习记忆功能及海马内神经颗粒素（Ng）表达的影响。方法将成年雄性昆明小鼠随机分为对照组、丙硫氧嘧啶（PTU）组、PTU＋T4（甲状腺素）组。对照组饮用自来水，PTU和PTU＋T4组饮用含0．1％PTU水。6周后，PTU＋T4组腹腔注射T4（20μg·kg^-1·d^-1），连续2周。Morris水迷宫观察小鼠的空间学习记忆能力，免疫组化分析海马各亚区Ng蛋白的表达。结果PTU组小鼠体质量、血清B、T4显著低于对照组（P〈0．05）；水下平台的潜伏期明显长于对照组（P〈0．05）；Ng蛋白表达水平海马CA1区（6．61±1．25）和齿状回DG区（6．40±0．94）低于对照组（8．91±1．08、8．82±1．23，P〈0．05）。T4替代治疗后，上述各项检查与对照组比较，差异无统计学意义（P〉0．05）。结论甲状腺功能减退可逆性损害成年雄性小鼠空间学习记忆功能，其机制可能与CA1和DG区Ng蛋白表达减少有关。Objective To study the effect of adult-onset hypothyroidism on spatial learning and memory and the expression of neurogranin （Ng） in the hippocampus in adult Kunming mice. Methods The adult male Kunming mice were randomly divided into control group, PTU group and PTU ＋ T4 group. The controls drank water only. The PTU and PTU ＋ T4 groups drank 0.1% propylthiouracil solution for 6 weeks, then the mice in the PTU ＋ T4 group were injected intraperitoneally with thyroid at a dose of 20μg·kg^-1·d^-1 for 2 weeks. 8 weeks afterwards, the spatial ability of learning and memory was measured in Morris water maze, followed by immunohistochemical test of the Ng levels in the different subfields of hippocampus. Results Body weight and serum T3,T4 levels in the PTU mice were significantly lower than those in the control mice（P 〈 0.05）. In the Morris water maze, the latency for the PTU mice to find the submerged platform was significantly longer than that for the control mice（P 〈 0.05 ）. Compared with the control mice, the average Ng level in the PTU mice significantly decreased in the areas of CA1 （control group = 8.91 ± 1.08, PTU group = 6.61 ±1.25） and DG （control group = 8.82 ±1.23, PTU group = 6.40 ±0.94） in the hippocampus （P 〈 0.05）, but no significant difference was observed in other areas. In the PTU ＋ T4 group, the serum T3 and T4 levels, spatial learning and memory ability, Ng levels in the CA1 and DG subareas in the hippocampus were returned to the normal after T4 replacement therapy, and the T4 treatment led to a slight increase in the mean body weights, but the difference among control and gFU mice was not significant（P 〉 0.05）. Conclusion The decreased Ng protein in the areas of CA1 and DG of hippocampus in the adult-onset hypothyroidism mice might be responsible for the reversible impairment of spatial learning and memory.

关 键 词：甲状腺功能减退症 学习 记忆 海马 神经组织蛋白质类 

分 类 号：R686[医药卫生—骨科学]