碘缺乏大鼠肾脏解耦联蛋白2与骨形态发生蛋白2的表达

The expression of uncoupling protein 2 and bone morphogenetic protein 2 in the kidney of iodine de-ficiency rats

目的通过测定碘缺乏大鼠肾脏解耦联蛋白（UCP）2、骨形态发生蛋白（BMP）2的表达，探讨其表达的改变与分布。方法实验前适应性喂养1周，应用随机数字表法将雌性Wistar大鼠分为3组：轻度低碘组（MIDG组）和重度低碘组（SIDG组），并设适碘组为正常对照组（CL组）（日总碘摄入量分别为5．00，1．24，10．00μg／d），每组10只，通过免疫组化等方法观察实验大鼠离体肾脏UCP2、BMP2的表达，并对结果进行相关统计学分析。结果与CL组相比，MIDG组血游离L、总L、总T4水平下降（t=2．54，1．81，4．41，P〈0．05），仅血游离rr4下降不明显，差异无统计学意义。SIDG组血游离T3、游离．T4、T3、总T4水平均明显下降（t=6．68，20．25，5．38，21．56，P〈0．01），与MIDG组相比，SIDG血激素水平下降更明显（t=3．19，15．45，6．93，13．48，P〈0．05）。免疫组化显示，UCP2与BMP2少量表达于肾小球，主要表达于肾皮质远端。肾小管。与CL组相比，MIDG组和SIDG组UCP2、BMP2表达量明显减少（t=5．72，8．79，8．74，18．63，P〈0．01），与MIDG组相比，SIDG组下降更明显（t=7．43，11．77，P〈0．01）。同时相关性分析显示这种下降趋势与血游离T4水平呈明显正相关（r=0．81，0．82）。结论碘缺乏可以导致甲状腺功能减退症（甲减），甲减大鼠肾脏UCP2、BMP2表达降低。

Objective To detect the expression of uncoupling protein 2 （UCP2） and bone morpho- genetic protein 2 （ BMP2 ） in the kidney of Wistar rats, and explore the changes and distribution of them. Methods Female Wistar rats were divided into mild iodine deficiency group （ MIDG group） , severe iodine deficiency group（SIDG group） and normal iodine group as control （CL group） with radom number table method,and fed adaptively for one week before the experiment with ten rats in each group （ everyday total iodine intaking were 5.00,1.24,10.00 μg/d, respectively）. Observed the expression of UCP2 and BMP2 in isolated kidney of the experimental rats through immunohistochemistry. And the results were analyzed with re- lated statistic methods. Results Compared with CL group, the level of free T3 , total T3 , total T4 in MIDG group declined （t =2. 54,1.81,4. 41 ,P 〈 0.05 ） ,while the level of free T4 did not decrease obviously, and the difference had no statistical significance. And the level of free T3 , free T4, total T3 , total T4 in SIDG group declined evidently （t =6. 68,20. 25,5.38,21.56,P〈 0. 01 ）. Compared with MIDG group, the level of blood hormone in SIDG group declined more obviously （ t = 3. 19,15.45,6. 93,13.48, P 〈 0.05 ）. hnmuno- histochemistry showed that UCP2 and BMP2 expressed mainly in the cortical distal renal tubular and less in glomeruli. Compared with CL group, the expression of UCP2 and BMP2 in SIDG group and MIDG group were both decreased significantly（ t = 5.72,8.79,8.74,18.63, P 〈 0.01 ）. Compared MIDG group, the expression in SIDG group declined more obviously （ t = 7. 43,11. 77, P 〈 0.01 ）. Meanwhile, the relevant analysis revealed that the tendencies of decline of UCP2 and BMP2 were consistent with the level of free T4 （ r = 0.81, 0.82）. Conclusion The deficiency of iodine can cause hypothyroidism which can lead to the decline of UCP2 and BMP2 in kidney of rats.