酪蛋白和高碘对小鼠甲状腺形态结构的影响

目的 观察酪蛋白和高碘对小鼠甲状腺形态结构的影响.方法 按2×3析因设计将实验小鼠分成6组,饮水分为适碘(50μg/L)、高碘(600μg/L)2个水平;饲料分为3个水平,Ⅰ:普通饲料,Ⅱ、Ⅲ:分别加入酪蛋白10%、20%的普通饲料.喂养12个月后,测定小鼠甲状腺质量,光、电镜观察甲状腺形态结构.结果 析因分析结果显示碘因素明显影响小鼠甲状腺绝对质量和相对质量(F值分别为1623、9.47,P＜0.01),且酪蛋白与碘之间具有交互作用(F值分别为5.29、4.68,P＜0.01或＜0.05).600 Ⅰ组[(7.60±2.40)rag、(143.3-1-43.2)mg/kg]、600Ⅲ组[(8.63±1.88)mg、(166.2±39.4)mg/kg]分别与50Ⅰ组[(5.91±0.82)mg、(117.0±22.2)mg/kg]和50Ⅲ组[(4.90-t-0.63)mg、(106.1±13.3)ng/kg]比较,甲状腺绝对质量和相对质量明显增高(P＜0.05或＜0.01)或具有增高趋势,而600Ⅱ组[(5.76±1.13)mg、(109.8±16.5)mg/kg]与600Ⅰ、600Ⅲ组比较,上述指标明显减少(P＜0.05或＜0.01).光、电镜下高碘组小鼠呈现高碘甲状腺肿、淋巴细胞浸润以及局部细胞代偿性功能增强现象,而随着酪蛋白摄入剂量增高,甲状腺形态结构改变程度明显减弱.结论 长期高碘可引发小鼠甲状腺胶质潴留性肿大和炎性损伤,对甲状腺炎的发生可能具有促进作用,而适当增加酪蛋白摄入可部分拮抗高碘引起的上述改变,对滤泡上皮细胞具有一定的保护作用.

Effects of excessive iodine and casein on histomorphalogy and ultrastructure of mouse thyroid

Objective To observe the effects of casein and excessive iodine on histomorphalogY and ultrastructure of mouse thymicL Methods Based on 2 × 3 factorial design,the experimental mice were divided into 6 groupg Animal models were estabhshed by feeding the mice with different levels of iodine water and casein food.The levels of iodine were 50,600 μg/L in drinking water and 0(Ⅰ),10%(Ⅱ),20%(Ⅲ)of casein in food respectively.After 12 months,the thyroid weight was measured and the morphology of thyroid was observed under optical and electron microscope.Results Factorial analysis showed that iodine factors obviously affected the thyroid absolute and relative weiights of mice(F=16.23,9.47,P＜0.01),and there was interaction between casein and iodine(F=5.29,4.68,P＜0.01 or＜0.05).Compared wiht 150Ⅰ[(5.91±0.82)rag,(117.0±22.2)mg/kg]and 50Ⅲ[(4.90±0.63)rag,(106.1±13.3)mg/kg]groups.thyroid absolute and relative weights of the mice increased in 600 Ⅰ[(7.60±2.40)mg,(143.3±43.2)mg/kg]and 600Ⅲ[(8.63±1.88)mg,(166.2±39.4)mg/kg]groups(P＜0.05 or＜0.01),respectively.But compared with 600 Ⅰ and 600Ⅲ groups.they were reduced obviously in 600Ⅱ[(5.76±1.13)mg,(109.8±16.5)mg/kg]group(P＜0.05 or＜O.01).Colloid goiter,lymphocyte infiltration were found,some of the follicles epithelial cells appeared active under light and electron microscope in iodine excels group,which,however,decreased obviously along with the increase of casein dose.Conclusions Long-term excessive iodine may cause colloid goiter and inflammation injury of mice,possibly leading the development of thyroiditis in mice,which may be partly reduced by casein.