不同碘濃度對大鼠甲狀腺攝碘功能的影響

馬曄 陳躍宇

摘 要：目的 觀察不同碘攝入量對大鼠促甲狀腺激素受體（TSHR）mRNA、鈉碘轉運體（NIS）mRNA以及血清過氧化物酶抗體（TPOAb）表達水平的影響。方法 SD大鼠30只，隨機分成低碘組（LI）、適碘組（NI）和高碘組（HI），每組10只。于實驗第8、16周分批處死。實時熒光定量聚合酶鏈式反應法測定TSHR mRNA及NIS mRNA表達水平。酶聯免疫分析法觀察血清TPOAb濃度。結果 實驗8周，低碘組和高碘組TSHR mRNA及NIS mRNA表達水平均低于適碘組，差異有統計學意義（P<0.05）；且血清TPOAb濃度高于適碘組，但差異無統計學差異（P>0.05）；實驗16周，高碘組和低碘組的TSHR mRNA和NISmRNA表達水平均明顯低于適碘組，差異有統計學意義（P<0.05）；血清TPOAb濃度高于適碘組，差異有統計學意義（P<0.05）。結論 包括碘過量和碘缺乏在內的長期碘營養障礙均可降低NIS及TSHR的正常表達，同時提高甲狀腺自身抗體的濃度，影響甲狀腺攝碘功能。

關鍵詞：碘；甲狀腺；鈉碘轉運體；促甲狀腺激素受體；甲狀腺過氧化物酶抗體

中圖分類號：R581 文獻標識碼：A DOI：10.3969/j.issn.1006-1959.2018.23.023

文章編號：1006-1959（2018）23-0083-03

Abstract：Objective To investigate the effects of different iodine intake on the expression of （TSHR） mRNA， sodium iodide transporter （NIS） mRNA and peroxidase antibody （TPOAb） in rat thyroid stimulating hormone receptor.Methods 30 SD rats were randomly divided into two groups： low iodine group （LI）， normal iodine group （NI） and high iodine group （HI），） 10 rats in each group. The rats were executed in batches at the 8th ，16th week.The expression levels of TSHR mRNA and NIS mRNA were measured by real-time fluorescence quantitative polymerase chain reaction. The concentration of serum TPOAb was observed by enzyme linked immunosorbent assay.Results At the 8th week of the experiment， the expression of TSHR mRNA and NIS mRNA in iodine deficiency group and high iodine group were lower than that in normal iodine group，the difference was statistically significant （P<0.05）.The concentration of serum TPOAb was higher than that of iodine group， but there was no significant difference （P>0.05）.At the 16th week of experiment， the expression levels of TSHR mRNA and NISmRNA in high iodine group and low iodine group were significantly lower than those in normal iodine group，the difference was statistically significant （P<0.05）.The concentration of serum TPOAb was higher than that of iodine group，the difference was statistically significant （P<0.05）.Conclusion Chronic iodine nutritional disorder，including iodine excess and iodine deficiency， can decrease the normal expression of NIS and TSHR， increase the concentration of thyroid autoantibodies and affect the iodine uptake function of thyroid.

Key words：Iodine；Thyroid；Sodium iodide transporter；Thyrotropin receptor；Thyroid peroxidase antibody

甲狀腺是人體重要的內分泌器官，它通過攝取碘合成甲狀腺激素來維持其正常的調節功能 。外界碘環境的變化可通過影響分布于甲狀腺濾泡細胞基底膜側的特異性鈉/碘轉運體（Na+/I-symporter，NIS）的表達來調節甲狀腺組織的攝碘功能[1，2]。與此同時，同樣分布于甲狀腺濾泡細胞基底膜側的促甲狀腺激素受體（TSHR）可與TSH結合并激活由c-AMP介導的信號級聯反應，上調NIS的表達并促進其向細胞膜轉運，調節其在濾泡細胞基底膜側的分布與定位，提高甲狀腺組織攝碘率。過氧化物酶（TPO）是甲狀腺微粒體抗原的重要組成部分之一 ，與自身免疫性甲狀腺疾病的發生發展密切相關。甲狀腺過氧化物酶抗體（TPOAb）是甲狀腺抑制性抗體，其生成過多會造成甲狀腺素的產生減少，影響甲狀腺的攝碘功能[3，4]。本實驗利用構建不同碘營養水平的大鼠動物模型，動態觀察碘對大鼠甲狀腺TSHR mRNA及NIS mRNA表達水平的影響，并動態監測長期碘營養障礙對甲狀腺自身抗體的影響。……