维生素A缺乏与补充对高碘小鼠甲状腺功能和抗氧化能力影响的动态研究

A trend study on the effect of deficiency and supplementation of vitamin A on thyroid function and antioxidative ability of mice taking excessive iodine

目的动态研究维生素A缺乏与补充对高碘小鼠甲状腺功能和抗氧化能力的影响。方法将小鼠按体重随机分为六组(1)正常对照组;(2)高碘组;(3)低维A组;(4)高碘低维A组;(5)高碘补维A1组;(6)高碘补维A2组。分别喂养1、3、6个月后,测定小鼠体质量与甲状腺质量,血清甲状腺激素水平和抗氧化能力的改变。结果3个月末、6个月末时高碘组小鼠甲状腺绝对质量和相对质量显著高于对照组;高碘补维A组小鼠的绝对质量和相对质量6个月时显著低于高碘低维A组,略轻于高碘组。1个月末时,高碘组血清T3水平升高,与对照组相比差异有统计学意义;6个月末时,高碘补维A组低于高碘组和高碘低维A组,相比较差异均有统计学意义。小鼠血清GSH-Px活性各组相比差异无统计学意义。高碘组SOD活性3、6个月末时显著高于对照组;高碘补维A组6个月时显著低于高碘组。6个月末时高碘组、高碘低维A组的MDA含量显著高于对照组;高碘补维A组显著低于高碘组、高碘低维A组,接近对照组水平。结论维生素A缺乏对高碘性甲状腺肿的形成有一定的协同作用,补充适量的维生素A对甲状腺肿的复原,以及抗氧化能力的提高都有一定的功效,但在甲状腺激素水平的改善上作用较弱。

Objective To trend study the effect of deficiency and supplementation of vitamin A on thyroid function and antioxidative ability of mice taking excessive iodine. Methods Kunming mice were divided into 6 groups： normal control （NI） group, high iodine （HI） group, low vitamin（LVA） group, high iodine and low vitamin A （ HI ＋ LVA） group, high iodine plus vitamin A1（HI ＋ VA1） group and high iodine plus vitamin A2（HI ＋ VA2） group. After 1 month, 3 months and 6 months, the weight of thyroid, thyroid hormones and antioxidative ability were measured respectively. Results Compared with NI group, both the relative and absolute weight of thyroid increased remarkably in HI group at the end of the 3rd and 6th month. At the end of the 6th month, both of them in HI group were lower than that in HI ＋ LVA group significantly . Serum T3 levels in all high iodine groups were remarkable different from that in NI group at the end of the 1 st month. At the end of the 6th month serum T3 levels in HI ＋ LVA group were different from that in HI ＋ VA group significantly. No remarkable differences of the activity of glutathione transferrase （GSH - Px） existed in all groups. The activity of superoxide dismutase （SOD） in HI group were significantly higher than that in NI group at the end of the 3rd and 6th month. At the end 6th month, the activity of SOD in two HI ＋ VA groups are significantly lower than that in NI group. The malondialdehyde （MDA） in HI and HI ＋ LVA groups are significantly higher than that in NI group at the end of the 6th month. The activity of MDA in two HI ＋ VA groups were nearly to the NI group and remarkable lower than that in HI and HI ＋ LVA groups. Conclusions Iodine excess may result in goiter and the change of antioxidative ability of mice. Deficiency of vitamin A may coordinat with the effect . Supplementation of sufficient vitamin A can help the recovery of the goiter and partially ameliorated the effect.