缺锌及补锌对大鼠甲状腺激素的影响

目的了解锌缺乏及补锌对大鼠甲状腺激素的影响。方法将出生后断乳1周的SD大鼠随机分为缺锌组、配喂组、对照组、补锌组和高锌组,缺锌组、对照组、高锌组分别用缺锌饲料(Zn含量<1mg/kg),常锌饲料(Zn含量为50mg/kg)和高锌饲料(Zn含量为150mg/kg)喂养8周,补锌组用缺锌饲料喂养3周后改用高锌饲料喂养5周,配喂组用常锌饲料喂养,给料量按缺锌组前一天实际进食量添加。8周后处死,用极谱法测定血清中锌的含量,用放射免疫法测定血清中FT3、FT4的含量。结果缺锌使大鼠血清中锌含量显著降低,血清中FT3含量下降,补锌后恢复正常,缺锌对FT4无影响。结论缺锌引起甲状腺激素FT3下降,而FT4不受影响。

Influence of Zinc Deficiency and Effects of Zinc Replenishment on the Thyroid Hormone of Rats Model

Objective The influence of zinc deficiency and effects of zinc replenishment on thyroid hormone of rats were studied. Methods SD rats were randomized into zinc-deficient diet (ZD) group, pair-fed (PF) group, zinc normal group(ZN), zinc supplemented (ZS) group and high zinc (HZ) group. ZD, ZN, HZ were fed with zinc deficient diet ( zinc<1 mg/kg), zinc-normal diet (50 mg/kg) and high zinc diet (150 mg/kg) for 8 weeks. ZS group were fed with zinc deficient diet for 3 weeks, and then turned to high-zinc diet for 5 weeks. PF group were fed with zinc normal diet according to the actual quantity of ZD group at the former day. All the animals were sacrificed at the end of the 8-week experiments, and the serum concentration of Zn were measured with polarography, serum concentration of FT_3 and FT_4 measured by radioimmunoassay. Results The serum concentration of Zn decreased significantly owing to zinc deficiency, while serum FT_3 content decreased because of zinc deficiency as well, and restored to normal after zinc was supplemented; when serum levels of FT_4 was not affected. Conclusions Zinc deficiency depresses the thyroid hormone, but FT_4 is not affected.