摘要
目的观察不同碘营养水平对哺乳期大鼠甲状腺和乳腺促甲状腺激素受体(TSHR)mRNA表达水平的影响。方法30只雌性Wistar大鼠按体质量随机分成3组:低碘组(合成饲料,去离子水);适碘组(合成饲料,含碘150μg/L的去离子水);高碘组(合成饲料,含碘3 000μg/L的去离子水)。喂养3个月后,与雄鼠合笼交配,待母鼠哺乳5 d后将其处死、取母鼠乳腺、甲状腺及血清,温和酸消化法测定血清碘;放射免疫分析法测定T3、T4水平;实时荧光定量PCR法检测乳腺和甲状腺TSHR mRNA表达水平。结果低碘组血清碘低于适碘组(P<0.05),高碘组血清碘高于适碘组(P<0.05);低碘组、高碘组T3水平低于适碘组(P<0.05);低碘组、高碘组T4水平与适碘组比较差异均无统计学意义(P>0.05),低碘组T4水平低于高碘组(P<0.05);低碘组甲状腺TSHR mRNA表达水平明显高于适碘组(P<0.05),高碘组低于适碘组,但差异无统计学意义;低碘组、高碘组乳腺TSHR mRNA表达水平都低于适碘组(P<0.05)。结论高碘时甲状腺和乳腺TSHR表达均减少,下调碘的摄入保护自身及子代免受碘过量的危害;轻度低碘时甲状腺提高TSHR表达以增加碘的摄入保护自身免受缺碘危害,但乳腺未增加摄碘能力,因此对子代没有保护作用或保护作用不明显。
Objective To study the effects of different levels of iodine concentration on thyrotropin receptor（TSHR） mRNA expression of thyroid and breast in lactating rats.Methods 30 Wistar female rats,having been weaned for one month,were randomly divided into three groups according to their body weights,i.e.,（1）low iodine（LI,10 rats）;（2）adequate iodine（AI,10 rats）;（3）high iodine（HI,10 rats）.Eating synthetic feed and drinking deionized water containing iodine of 0,150,3 000 μg/L,respectively.After fed for 3 months,the rats mated and had offspring.Their mammary glands,thyroids and serum were sampled at lactation day 5.The serum iodine of lactating rats were determined by moderate acid digestion method,T3,T4 levels were determined by radioimmunoassay method,and the expressions of TSHR mRNA of mammary glands and thyroids were determined by real-time fluorescence quantitative PCR assay.Results The mean of serum iodine of LI group[（17.38 ± 3.27）μg/L] was lower than that of AI group [（43.42 ± 6.92）μg/L]（P〈 0.05）,and the level of serum iodine of HI group [（350.10 ± 38.46）μg/L] was higher than that of AI group（P〈 0.05）.The level of T3 of LI group and HI group [（1.11 ± 0.25）μg/L,（1.61 ± 0.33）μg/L] reduced obviously compared with that of AI group [（2.18 ± 0.46）μg/L]（P〈 0.05）.The mean of T4 of LI group [（33.40±11.11）μg/L] and HI group [（56.54±10.38）μg/L]had not statistically significant compared with AI group[（44.02 ±12.51）μg/L]（P〉0.05）,but the level of T4 of LI group was lower than that of HI group（P〈 0.05）.The mean of TSHR mRNA expression of thyroid in LI group（1.28±0.31）was higher than that of AI group（0.76±0.34,P〈 0.05）.The mean of TSHR mRNA expression of thyroid in HI group（0.49±0.30） was lower than that of AI group,but there was no statistical difference.The mean of TSHR mRNA expression of lactating mammary in LI group and in HI group（0.30±0.11,0.74±0.26）were lower than that of AI group（1.24±0.30,P〈0.05）.Conclusion TSHR mRNA expression in thyroid and breast were reduced by excessive iodine,to protect mother and its next generation from the high-iodine hazards.Mild iodine deficiency could increase the level of TSHR mRNA expression in thyroid and promote thyroid＇s ability of iodine intake,to protect mother from the iodine deficiency hazards.But the iodine intake capacity of mammary gland had not increased,so there was no protective effect or protective effect was not obvious for the next generation.
出处
《中国地方病防治》
CAS
2010年第1期4-7,共4页
Chinese Journal of Control of Endemic Diseases
基金
国家自然科学基金
面上项目(30671817)
