不同剂量碘对孕鼠胸腺CK19阳性上皮细胞的影响

Effect of different concentrations of iodine on CK19^+ thymic epithelial cells

目的研究摄入不同剂量碘化钾对孕鼠胸腺细胞角蛋白19阳性(CK19+)上皮细胞的影响。方法取断乳后1个月的雌性Wistar大鼠,随机分为5组:重度低碘组、中度低碘组、轻度低碘组、适碘组、高碘组。分别给予不同浓度的碘化钾。饲养3个月后,与按适量碘饲养的雄性大鼠合笼交配。在孕16d处死雌鼠,测定血清甲状腺激素水平、胸腺CK19+上皮细胞的体密度和面数密度。结果与适碘组相比较,重度低碘组和中度低碘组的T4均显著降低(P<0.05),且胸腺CK19+上皮细胞的体密度和面数密度亦显著降低(P<0.05),其中重度低碘组下降程度更明显。轻度低碘组及高碘组T4、T3有降低,但无统计学意义。结论长时间的摄碘异常(碘缺乏、碘过量)可使孕鼠甲状腺激素水平降低,从而导致胸腺CK19+上皮细胞减少,胸腺退化,且低碘对孕鼠的影响比高碘更为显著。

Objective To study the changes of CK19^＋ thymic epithelial cells after intake of different concentrations of Potassium iodine（ KI）. Methods Female Wistar rats, 1 month after stopping lactation, were divided randomly into 5 groups by giving various concentrations of KI： the lowest iodine（L1）, the lower iodine（L2）, low iodine（L3）, normal iodine（NI）, high iodine （ HI）. After three months, the rats mated with male rats fed with normal - iodine diet. On the 16th day of pregnancy , we measure thyroid hormones in serum, and observe volume density（Vv） and numerical density on area（NA） of thymus CK19^＋ thymic epithelial cells. Results Compared with normal group, T4 decreased dramatically, Volume density（Vv） and numerical density on area（NA） of thymus CK19^＋ epithelial cells also decreased significantly in L1 and L2（ P 〈 0.05）, especially, the decrease in L1 is more dramatic; the decrease in L3 and HI has no statistical significance. Conclusions Long time of abnormal intake of KI（ deficiency or overdose） results in decreased thyroid hormone level, thereafter CK19^＋ thymic epithelial cells decrease and thymus degenerate. And the influence of deficiency of iodide is more dramatic than overdose of iodide.