锌对缺碘大鼠仔鼠甲状腺和脑发育影响的实验研究

Experimental study of zinc on the thyroid and brain growth in fetal rats with iodine deficiency

目的 观察不同碘营养水平母鼠生育的仔鼠甲状腺形态、大脑重量及脑组织中蛋白质、DNA、RNA含量变化及锌对其的影响作用。方法 应用缺碘饲料喂养Wistar雌性大鼠复制缺碘动物模型 ,同时设补碘、补复合锌和葡萄糖酸锌、补碘加复合锌等组。 3个月时将动物模型进行交配繁育仔鼠 ,1个月后处死仔鼠 ,取垂体、甲状腺进行病理学检查 ,生物化学方法检测大脑组织中蛋白质、DNA、RNA含量。结果 缺碘组大鼠生育的仔鼠体重增长缓慢 ,甲状腺肿大 ,大脑重量减轻 ,脑中蛋白质、DNA、RNA含量降低 ,同时RNA/DNA比值和蛋白质 /DNA比值降低。补锌组的仔鼠甲状腺肿大程度较缺碘组减轻 ,体重增加 ,脑蛋白质、DNA、RNA含量和RNA/DNA、蛋白质 /DNA比值升高。结论 原代缺碘大鼠补锌 ,降低其生育的仔鼠甲状腺肿大程度 ,使大脑蛋白质、DNA、RNA含量增加 ,拮抗缺碘所致的脑发育障碍。

Objective To observe the effects of zinc(Zn) on the changes of the thyroid morphology,the contents of protein,deoxyribonucleic acid(DNA) ribonucleic acid(RNA) in the fetal rats which were given birth by the rats in different levels of iodine.Methods Wistar female rats with iodine deficiency were duplicated with fodder of Iodine Deficiency Disorder(IDD) areas and iodine(I),compound zinc(ZnC),zinc gluconate(ZnG)were given in rats of other 4 groups with I deficiency.In 3 months,the 5 experimental groups and control group of female rats mated with male rats and the contents of protein,DNA and RNA were measured in fetal rats.Results In the groups of the fetal rats with I deficiency,the slowness in the in the increase weight and the goiter were determined.There was a derease of the brain weight.The content of the protein,DNA and RNA in the brain,the rate of RNA/DNA and Pr/DNA debased.At the same time,The female rats weight ascended and the weight of thyroid were lowered than that in the group of I deficiency.There was an increase in the content of the protein,DNA and RNA in the brain and in the rate of RNA/DNA and Pr/DNA ascended in 2 groups of Zn administration.Conclusions In I deficiency of rats,Zn supplementation could decrease the degree of goiter,ascend the content of the protein,DNA and RNA and antagonize the obstacl of brain growth in the fetal rats caused by I deficiency.