中文摘要：

目的观察不同碘营养水平对哺乳期大鼠乳腺组织丝裂原活化蛋白激酶（MAPK）激酶（mitogen extracellular kinase，MEK）、细胞外信号调节激酶（extracellular signal—regulated kinase，ERK）及钠碘转运体（Na＋-I^-Symporter,NIS）的表达及血清雌二醇（estradiol，E2）水平的影响，探讨在差异性碘饮食中哺乳期乳腺MEK—ERK信号通路的摄碘机制。方法Wistar大鼠130只（雌鼠100只、雄鼠30只），按体质量采用随机数字表法将雌鼠分为5组：①A组（低碘1组）：低碘饲料（碘含量为16．15μg／b）＋不加碘的去离子水；②B组（低碘2组）：低碘饲料＋碘含量为5．00μg／L的去离子水；③C组（适碘组）：普通饲料（碘含量为350．00μg／kg）＋碘含量为50．00μg／L的去离子水；④D组（高碘1组）：普通饲料＋碘含量为3000．00μg／L的去离子水；⑧E组（高碘2组）：普通饲料＋碘含量为10000．00μg／L的去离子水。每组20只大鼠，饲养90d后，将5组雌鼠与雄鼠合笼，交配后，将雄鼠取出，每只雌鼠单独喂养；在生育第10天，将母鼠处死，收集血液离心后获取血清，采用放射免疫法检测E2水平；取出乳腺组织，应用实时荧光定量PCR法、蛋白免疫印迹法（Western blot）法检测MEK、ERK及NISmRNA和蛋白的表达。结果哺乳期大鼠E2水平组间比较差异有统计学意义（r=12．765，P〈0．05）。其中A组[（1．22±0．46）ng／L]明显高于C组[（0．77±0．38）ng／L]，D组[（0．41±0．21）ng／L]、E组[（0．36±0．15）ng／L]均低于C组，差异均有统计学意义（P〈0．01或〈0．05）。哺乳期大鼠乳腺NIS、MEK、ERKmRNA表达组间比较差异均有统计学意义（F=14．916、10．757、45．172，P均〈0．05）。其中A组（0．75±0．40）、B组（0．89±0．51）NIS113RNA表达明显高于C组（0．53±0．31，P〈0．05或〈0．01），E组（0．30±0．24）NISmRNA表达明显低于C组?

英文摘要：

Objective To observe the variation of mitogen extracellular kinase （MEK）, extracellular signal-regulated kinase （ERK）, sodium iodide symporter （NIS） mRNA and protein expression in mammary tissues and serum estradiol （E2） in lactating rats under different iodine nutrition levels, and to study the role of MEK-ERK signaling pathway in the process of mammary gland intaking iodine during lactation period. Methods Totally 130 Wistar rats （100 female rats, 30 male rats） were divided into five groups by random number table method according to body weight： （1） group A （low iodine group 1）： rats were fed with low iodine diet and deionized water; （2） group B （low iodine group 2）： rats were fed with low iodine diet and deionized water with 5 μg/L iodine; （3） group C （control group）： rats were fed with normal diet and deionized water with 50 μg/L iodine; （4） group D （high iodine group 1）： rats were fed with normal diet and deionized water with 3 000 μg/L iodine; （5） group E （high iodine group 2）： rats were fed with normal diet and deionized water with 10 000 μg/L iodine, 20 rats in each group. After 90 days, the female rats and male rats of the 5 groups were mated. After mating, the male rats were removed, each female rat was fed individually, ten days after given birth, the female rats were sacrificed, blood was collected and centrifugated to obtain serum. E2 level was detected by radioimmunoassay; the breast tissue was collected, the expression of MEK, ERK and NIS mRNA and protein was detected using real-time fluorescence quantitative PCR and Western blotting. Results The differences of serum E2 levels in lactating female rat were statistically significant in the five groups （F = 12.765, P 〈 0.05）. The level of E2 in group A [（1.22 ± 0.46） ng/L] was significantly higher than that in group C [（0.77 ± 0.38） ng/L], the level of E2 in groups D and E [（0.41 ± 0.21）, （0.36 ± 0.15） ng/L] was significantly lower than that in group