突触相关蛋白25在成年期甲状腺功能减退症大鼠额叶内表达变化及甲状腺素治疗效应  

SNAP-25 expression in the prefrontal cortex of rats with adult-onset hypothyroidism and the therapeutic effect of thyroxine

作　　者：刘俊霞[1] 贾雪梅[2] 桂丽[2] 朱德发[3] 马维青[1] 

机构地区：[1]安徽合肥市第一人民医院内分泌科,230061 [2]安徽医科大学综合实验室 [3]安徽医科大学第一附属医院老年内分泌科

出　　处：《中国临床保健杂志》2011年第3期284-287,I0001,共5页Chinese Journal of Clinical Healthcare

基　　金：国家自然科学基金(30772301);安徽省自然科学基金(070413084)

摘　　要：目的研究成年期甲状腺功能减退症(甲减)大鼠额叶内突触相关蛋白25(SNAP-25)的表达及甲状腺素替代治疗后的恢复状况,探讨甲减脑损伤及恢复的分子基础。方法用丙基硫氧嘧啶(PTU)建立成年期大鼠甲减模型,采用放射免疫法测定甲减组、常规剂量甲状腺素替代治疗组、大剂量甲状腺素替代治疗组、健康对照组大鼠的血清甲状腺素水平,免疫组织化学方法分析四组大鼠额叶内SNAP-25蛋白的表达情况。结果与健康对照组相比,甲减组大鼠血清T3、T4水平显著减低(P<0.02);常规剂量(5μg.kg-1.d-1)替代治疗后,血清T3、T4恢复至正常水平。甲减组额叶I、II、III、IV、V层SNAP-25蛋白的表达水平显著高于健康对照组(P<0.01);常规剂量替代治疗组SNAP-25表达水平与健康对照组比较未见明显差异;与甲减组相比,大剂量(20μg.kg-1.d-1)替代治疗组SNAP-25表达水平在额叶各层显著减低(P<0.05)。结论成年期甲减大鼠额叶SNAP-25蛋白表达增多,常规及大剂量甲状腺素替代治疗后均可降低该蛋白表达,大剂量替代治疗后SNAP-25表达水平更接近正常。Objective To observe the expression of SNAP-25 in prefrontal cortex of adult-onset hypothyroidism rats and explore the molecular mechanism of brain injury of hypothyroidism.Methods 45 adult Sprague-Dawley rats were separated into 4 groups randomly,i.e.control group（n=11）,hypothyroidism group（n = 12） and hypothyroidism treated with T4（5 or 20 μg/100g body weight） group（n = 11）.The hypothyroidism models were replicated with 6-n-propyl-2-thiouracil（PTU）.The levels of serum T3,T4 were assayed by radioimmunoassay method.The level of SNAP-25 in prefrontal cortex was analyzed by immunohistochemistry.Results Compared to the control group,the serum levels of T3 and T4 were significantly lower in the hypothyroid group（P〈0.02）,and the level of SNAP-25 expression was significantly higher in the I,II,III,IV and V layers of prefrontal cortex in the hypothyroid compared to those of the control group（P〈0.01）.Compared to the hypothyroid group,the SNAP-25 expression was significantly lower in all layers in T4-20 group（P〈0.05）,and there was no significant difference between the treatment groups and control group.Conclusion The expression of SNAP-25 in the prefrontal cortex of adult-onset hypothyroidism is increased,which may be down-regulated by thyroid hormone replacement therapy.

关 键 词：甲状腺功能减退症 突触体相关蛋白质25 额叶 激素替代疗法 

分 类 号：R581.2[医药卫生—内分泌]