碘缺乏和甲状腺功能减退对大鼠仔鼠小脑CaM和CaN表达的影响

Effects of Cerebellar development and the expression of CaM、CaN in the Cerebellum of Iodine Deficient and Hypothyroid Pup Rats

目的观察碘缺乏及甲状腺功能减退对大鼠仔鼠小脑发育的影响,以及对CaM、CaN表达的影响。方法W istar大鼠交配妊娠后,取孕鼠28只按体重随机分成对照组、甲状腺功能减退-1组、甲状腺功能减退-2组和碘缺乏组。自妊娠第6日起,对照组继续饲以普通饲料;甲减-1组、甲减-2组分别给予5 ppm、15 ppm丙基硫尿嘧啶饮水,饲以普通饲料;碘缺乏组饲以缺碘地区粮食配制的饲料,至仔鼠生后第28 d(PN28)。PN7、PN14、PN21、PN28、PN42取仔鼠小脑皮质进行CaM、CaN蛋白免疫组化染色。结果PN14、PN21、PN28及PN42时,甲减-2组和碘缺乏组仔鼠小脑皮质CaM的平均积分光密度值显著低于对照组和甲减-1组,具有统计学意义(P<0.05);碘缺乏组仔鼠小脑皮质CaN表达均显著高于对照组,具有统计学意义(P<0.05)。结论碘缺乏和甲状腺功能减退可影响大鼠仔鼠小脑CaM、CaN蛋白的表达,从而损害仔鼠小脑,导致脑神经发育障碍。

Objective We have tested whether congenital iodine deficiency and hypothyroidism could regulate expression of CaM,CaN in pup Cerebellum cortex, and impair functional lesion in pup Cerebellum. Methods Female Wistar rats （ n = 28） after pregnancy were randomly divided into four groups： control group, iodine deficient group, hypothyroid - 1 group （Sppm） and hypothyroid- 2 group （15ppm）. The control group was fed a normal diet during the experiment. The iodine deficient group was fed an iodine - deficient 6diet. The hypothyroid - 1 group was fed a normal diet and had 5ppm PTU - added water and the hypo- thyroid - 2 group had 15ppm PTU - added water. All the groups were from GD6 through to postnatal day （PN） 28. On PNT, PN14, PN21, PN28, pups in each group the part of the cerebellum was separated from the brain for protein detection by CaM, CaN immunohistochemistry. Results On PN14, PN21, PN2g and PN42, CaM expression in 15ppm and iodine - deficient groups were significantly lower than those of controls and 5ppm （ P 〈 0.05） ; CaN expression in iodine - deficient groups were significantly higher than those of controls （ P 〈 0.05）. Conclusion Iodine deficiency and hypothyroidism during a period of brain development changed cerebellar morphology and effected the expression of CaM,CaN. The changes are likely to impaired synaptic plasticity, effected the formation of normal neural circuit, and resulted in cerebellar development disturbance.