碘缺乏和甲状腺功能减退对大鼠仔鼠小脑cAMP反应元件结合蛋白表达的影响

目的 研究碘缺乏和甲状腺功能减退对大鼠仔鼠小脑cAMP反应元件结合蛋白(CREB)表达的影响.方法 分别选用低碘饲料及丙基硫尿啼啶(propylthiouracil,PTU)饮水诱导建立低碘及甲状腺功能减退Wistar大鼠动物模型,按体重随机分成对照组、甲状腺功能减退组(5 mg/L PTU组、15 mg/L PTU组)和碘缺乏组,出生后第14天(PN14)、PN21、PN28、PN42时,测定仔鼠小脑重量,PN7、PN14、PN21、PN28、PN42时取小脑组织进行免疫组织化学链霉菌抗生物素蛋白-过氧化物酶(SP)染色,用图像分析方法分析大鼠仔鼠小脑皮质CREB表达情况.结果 PN14、PN21、PN28、PN42时,碘缺乏组小脑重量显著低于对照组和甲状腺功能减退组(P＜0.05).PN7时,各组之间小脑组织CREB平均积分光密度值差别不明显,而PN14,PN21,PN28和PN42时,5、15 mg/L PTU组和碘缺乏组平均积分光密度值均低于对照组(P＜0.05).结论 碘缺乏和甲状腺功能减退可降低大鼠仔鼠小脑组织CREB表达,影响神经系统的发育.

Abstract：

Objective To study the effects of iodine deftcieney and hypothyrosis on protein expression of CREB in the cerebellum of rats.Methods Iodine deficient rats were administered with iodine-deficient diet and hypothyroid rats were administered with PTU in drinking water.Female Wistar pregnant rats (n=28)were randomly divided into four groups:control group,iodine deficient group,5 mg/L PTU group and 15 mg/L PTU group.On PN14,PN21,PN28,pups cerebellum in each group were weighed.On PN7.PN14,PN21,PN28,cerebellum tissue were determined for CREB protein detection by immunohistochemistry.Results Cerebellum weights of pup from iodine-deftcient were significantly lighter than control,5 mg/L and 15 mg/L groups on PN14,PN21,PN28 and PN42.In the result of immunohistochemistry:on PN7,there was no significant difference in all the groups.On PN14,PN21,PN28 and PN42,CREB expression in 5,15 mg/L and iodine-deficient groups was significantly lower than that of the control group(P＜0.05).Conclusion Iodine deficiency and hypothyrosis during critical periods brain development may down regulate the protein expression of CREB,which may result in damage of serebellum development.

Effects of Iodine Deficient and Hypothyrosis on Protein Expression of CREB in the Cerebellum of Rats

Objective To study the effects of iodine deftcieney and hypothyrosis on protein expression of CREB in the cerebellum of rats.Methods Iodine deficient rats were administered with iodine-deficient diet and hypothyroid rats were administered with PTU in drinking water.Female Wistar pregnant rats (n=28)were randomly divided into four groups:control group,iodine deficient group,5 mg/L PTU group and 15 mg/L PTU group.On PN14,PN21,PN28,pups cerebellum in each group were weighed.On PN7.PN14,PN21,PN28,cerebellum tissue were determined for CREB protein detection by immunohistochemistry.Results Cerebellum weights of pup from iodine-deftcient were significantly lighter than control,5 mg/L and 15 mg/L groups on PN14,PN21,PN28 and PN42.In the result of immunohistochemistry:on PN7,there was no significant difference in all the groups.On PN14,PN21,PN28 and PN42,CREB expression in 5,15 mg/L and iodine-deficient groups was significantly lower than that of the control group(P＜0.05).Conclusion Iodine deficiency and hypothyrosis during critical periods brain development may down regulate the protein expression of CREB,which may result in damage of serebellum development.