碘过量对仔鼠小脑浦肯野细胞发育影响的实验观察

Influence of iodine excess on the development of cerebellum Purkinje cells in filial generation of rats

目的探讨碘过量对Wistar大鼠仔鼠小脑浦肯野（Purkinje）细胞的形态学影响。方法将断乳后1个月的Wistar大鼠随机分为5组（NI、5HI、10HI、50HI、100HI），饮用含不同质量浓度的碘水，饲养3个月后雌雄合笼，取第2代1、20、60日龄仔鼠，测量血清甲状腺激素，动态观察仔鼠的小脑发育。结果在60日龄时，各碘过量组甲状腺激素水平呈下降趋势，100HI组呈明显甲状腺功能低下状态；在1日龄仔鼠，与NI组相比，各碘过量组仔鼠Purkinje细胞树突覆盖面积、分支密度、总长度、棘突密度、总棘突数均无明显变化（P〉0．05），在20日和60日龄仔鼠，各碘过量组与NI组相比均表现出一定程度的脑发育落后，其中以100HI组最为明显（P〈0．05或〈0．01）。结论碘过量会影响大鼠子代的小脑发育，其机理可能与高碘所致甲状腺功能低下有关，但大鼠对高碘有极强的耐受力，当碘摄入量小于正常摄入量的50倍时，不会影响仔鼠小脑Purkinje细胞的发育。

Objective To study the effects of different doses iodine excess on cerebellum Purkinje cells in filial generation of Wistar rats. Methods The rats were divided into five groups （NI,5HI, 10HI ,50HI, 100HI ） by feeding with water of different levels of iodine. After three months, the rats mated and their filial generations of 1-day, 20-day and 60-day were observed. The changes of cerebellum development were observed. Results The serum thyroid hormone were gradually decreased in iodine excess groups, hypothyroidism occured in 100HI group of 60..day rats. In filial generations of 1-day, the cross section area, the exponent, density and distributional types of spinal processes in cerebellum Purkinje cells did not remarkably change among different groups（P 〉 0.05 ）. The cerebellum development of filial generations of 20-day and 60-day were delayed along with time compared with normal controls （P 〈 0.05 or 〈 0.01 ）. Conclusions Iodine excess would affect the development of the Purkinje cells in the filial generations, and the mechanism is perhaps related with hypothyroidism induced by iodine excess. Wistar rats are well tolerated to high doses of iodine, so iodine intake within 50HI has no effect on their development of the Purkinje cells in the filial generations.