大鼠脱碘酶、硒蛋白P和硒蛋白W正常表达所需的最低饲料硒水平

目的　研究能满足大鼠脱碘酶、硒蛋白 P和硒蛋白 W合成所需的饲料硒水平。方法　以低硒酵母合成饲料加不同剂量的亚硒酸钠配成硒水平分别为 0 .0 1、0 .0 2、0 .0 3、0 .0 4、0 .0 5、0 .0 6、0 .1 0和 0 .2 0 mg/kg的 8种饲料喂养雄性 wistar断乳大鼠。 2 0周时杀死大鼠取其组织 ,分别对各种组织中的 型、 型和 型脱碘酶、硒蛋白 P的 m RNA以及硒蛋白 W的 m RNA的水平进行测定。结果　能满足大鼠各组织 型、 型和 型脱碘酶发挥最佳活性时的最低饲料硒水平为0 .0 5mg/kg,而硒蛋白 P的 m RNA以及硒蛋白 W的 m RNA正常表达所需的最低饲料硒水平分别为 0 .0 5和 0 .0 6mg/kg。结论　饲料硒水平达到 0 .1 mg/kg可满足大鼠脱碘酶、硒蛋白 P和硒蛋白 W的合成。

THE LEAST DIETARY SELENIUM REQUIREMENTS FOR NORMAL EXPRESSION OF DEIODINASE AND SELENOPROTEIN P AND W IN RATS

Objective: To estimate the dietary Se requirements for the synthesis of deiodinases and selenoprotein P and selenoprotein W in rats. Method: The basal selenium (Se) deficient diet was a Torulayeast based semisynthetic diet containing 0.01 mg Se/kg. The basal diet was supplemented with Se as Na 2SeO 3 to different Se levels to form the experimental diets. Male weaning Wistar rats were randomly assigned to one of the eight dietary treatment groups. Each group was fed the diet containing 0.01, 0.02, 0.03, 0.04 0.05, 0.06, 0.10 and 0.20mg Se/kg respectively. At the end of 20 weeks, rats were killed and organs were taken. The Se concentration and activities of type Ⅰ deiodinase (ID Ⅰ), type Ⅱ deiodinase (ID Ⅱ), type Ⅲ deiodinase and the mRNAs of selenoprotein P and selenoprotein W were measured in different tissues. Results: The least dietary selenium requirement for the optimal activities of type deiodinases was 0.05 mg Se/kg diet, the least dietary Se for the normal expression of selenoprotein P and selenoprotein W were 0.05 mg Se/kg diet and 0.06 mg Se/kg diet respectively. Conclusion: 0.1 mg Se/kg diet is required for the synthesis of deiodinases, selenoprotein P and selenoprotein W.