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Objective To observe the effects of casein on iodine metabolism in blood,urine and thyroid of mice under excessive iodine.Methods A 2 by 3 factorial design was used in the experiment.The levels of iodine and casein were 50 and 600 μg/L in drinking water and 0( Ⅰ ),10％( Ⅱ ),20％( m ) in food,respectively.After six and twelve months,iodine content in serum,thyroid gland and urine was determined by arsenic-cerium catalyzed spectrophotometry.Results In six months,the levels of serum iodine in 50 Ⅰ,50 Ⅱ,50Ⅲ,600 Ⅰ,600 Ⅱ,and 600Ⅲ groups were (85.59 ± 8.78),(64.59 ± 9.06),(72.53 ± 11.69),(110.04 ± 9.37),(81.06 ± 9.94),(86.63 ± 19.59)μg/L,respectively; the levels of iodine content in thyroid gland were (0.21 ± 0.09),(0.29 ±0.08),(0.24 ± 0.05),(0.50 ± 0.10),(0.37 ± 0.13),(0.42 ± 0.12)g/kg,respectively; the levels of urinary iodine median were 87.5,68.1,105.5,746.5,828.3,1014.2 μg/L,respectively.The variance analysis results of factorial design showed iodine and casein significantly influenced the serum iodine level(F =27.95,18.52,all P ＜0.05),however,there was no interaction between the two(F =0.81,P ＞ 0.05); iodine significantly influenced the iodine content in thyroid gland(F =31.35,P ＜ 0.05),the presence of iodine interacted with casein(F =3.34,P ＜0.05).In twelve months,the levels of serum iodine were (88.54 ± 12.33),(72.45 ± 7.73),(72.93 ± 13.61),( 106.26 ± 12.00),(90.03 ± 7.90),( 104.88 ± 11.67)μg/L,respectively; the levels of iodine content in thyroid gland were (0.58 ± 0.12),(0.40 ± 0.14),(0.69 ± 0.16),(0.84 ± 0.13),(0.89 ± 0.13),(1.02 ± 0.11 )g/kg,respectively;the levels of urinary iodine median were 104.8,121.5,102.7,829.1,1080.8,895.2 μg/L,respectively.The variance analysis results of factorial design showed iodine and casein significantly influenced the iodine content in serum and thyroid gland (F =42.78,7.42 and 66.62,7.90,all P ＜ 0.05),however,there was no interaction between the two(F =1.93,2.31,all P ＞ 0.05).Conclusions Long-term intake of iodine can significantly increase the iodine content in serum,thyroid gland and urine,but casein may accelerate iodine excretion and partly reduce the effect.
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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.
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<p><b>OBJECTIVE</b>To study the factors leading to the variation of children's total goiter rates, urine iodine and salt iodine in West China.</p><p><b>METHODS</b>Design effect (DEFF) was used to evaluate the variation of indicators.</p><p><b>RESULTS</b>DEFF of children's total goiter rate was about 3.0 in 9 provinces, and the proportion was 75.0%. The DEFF of urine iodine was 1.0 - 3.5 in 6 provinces, and the proportion was 50.0%. The DEFF of intake rate of qualified iodized salt was over 3.0 in 11 provinces. The DEFF of covering rate of iodized salt was about 3.0 in 4 provinces.</p><p><b>CONCLUSION</b>In order to provide scientific basis for IDD surveillance in China, other than bias due to methods of no-sampling, sample size should be further calculated in West China. Thus the main influencing factors of indicator variation could be measured with scientific and reasonable basis.</p>