成年期甲减大鼠海马syntaxin-1表达及甲状腺素干预效应  

Effect of the syntaxin-1 expression on the hippocampus of adult hypothyroidism rats and thyroxine intervention

作　　者：宁丹[1] 朱洋波[1] 沈玉先[2] 朱德发[1] 

机构地区：[1]安徽医科大学第一附属医院老年内分泌科老年病研究所,合肥230022 [2]安徽医科大学教育部"重要遗传疾病基因资源利用"重点实验室(省部共建),合肥230032

出　　处：《安徽医科大学学报》2011年第11期1138-1141,共4页Acta Universitatis Medicinalis Anhui

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

摘　　要：目的观察成年期甲状腺功能减退症(简称甲减)大鼠海马突触相关蛋白syntaxin-1表达及不同剂量甲状腺素干预后的恢复情况,探讨甲减脑损伤及替代治疗的可能分子机制。方法通过腹腔注射丙基硫氧嘧啶建立成年期甲减大鼠模型(甲减组)共6周,第5周起每100 g体重腹腔注射给予左旋甲状腺素5μg(常规剂量组)或20μg(大剂量组),对照组腹腔注射给予等体积生理盐水共6周。采用放射免疫法测定血清T3、T4水平,Western blot法分析各组大鼠背侧海马内syntaxin-1表达。结果与对照组比较,甲减组大鼠血清T3、T4水平降低(P<0.05),常规剂量组血清T3、T4水平差异无显著性;与对照组比较,甲减组大鼠背侧海马突触小体内syntaxin-1水平升高(P<0.05),常规剂量组和大剂量组syntaxin-1表达水平差异均无显著性,其中大剂量组有进一步恢复的趋势。结论成年期甲减大鼠海马syntaxin-1表达增加,常规剂量治疗能使syntaxin-1表达恢复至正常水平,大剂量干预时表达更接近正常。Objective To observe the expression of syntaxin-1 in hippocampus of adult hypothyroidism rats before and after different dosages of thyroxine intervention,and to explore the molecular mechanism of brain injury by hypothyroidism and recovery by replacement therapy.Methods The adult hypothyroidism models were rendered by ip injection 6-n-propyl-2-thiouracil（PTU） for six weeks,from the fifth week,the rats received L-thyroxine 5 μg/100 g BW or 20 μg/100 g BW by ip injection respectively in routine and high dosage group.The serum T3 and T4 were assayed by radioimmunoassay method,and the level of syntaxin-1 in hippocampus was analyzed by Western blot.Results Compared with the control group,serum T3 and T4 were significantly lower in hypothyroidism group（P0.05）,but no significant difference in routine dosage group,the expression of syntaxin-1 protein in the crude synaptic knob of dorsal hippocampus was significantly increased in hypothyroidism group（P0.05）,after intervention of routine and high dosage of L-thyroxine,the levels of syntaxin-1 protein were not significantly diffrent in control group,and in the high dosage of L-T4 group,the level of syntaxin-1 protein was more closely in the control group.Conclusion The expression of syntaxin-1 was increased in hippocampus of adult hypothyroidism rats,routine dosage L-thyroxine can reverse the alteration,high dosage is prior to routine dosage to restore the protein level.

关 键 词：甲状腺功能减退症 syntaxin-1 WESTERNBLOT 海马 

分 类 号：R581.2[医药卫生—内分泌] R446.63[医药卫生—内科学]