过量碘对仔鼠脑神经颗粒素表达的影响及硒的干预作用

Intervention of selenium on neurogranin expression in filial cerebrum of mice with excess iodine

目的研究过量碘摄入对小鼠仔鼠脑神经颗粒素表达的影响及硒的干预作用。方法将60只 BALB/c 小鼠用随机数字表法随机分为4组:正常对照组(饮用自来水,NC)、过量碘组(饮水3000 μg/L I,EI^+)、单独补硒组(饮水200 μg/L Se,Se^+)、过量碘加硒组(饮水3000 μg/L I+200 μg/LSe,EI+Se^+)。以纯系鼠饲料饲养。4个月后,雌雄交配。测定14和28 d 龄仔鼠血清总 T_4(T_4)和总T_3(T_3)水平,用免疫组织化学法和 Western blot 测定14和28 d 龄仔鼠大脯组织神经颗粒素蛋白的表达。结果 14 d 龄仔鼠血清 T_4水平过量碘组(68.78±11.10)nmol/L 低于对照组(100.85±11.47)nmol/L 和过量碘加硒组(93.15±12.10)nmol/L。Western blot 研究结果显示14 d 龄仔鼠脑组织神经颗粒素相对水平过量碘组0.621±0.041低于正常对照组0.841±0.039和 EI^+Se^+0.781±0.029。过量碘和补硒对28d龄仔鼠血清 T_4和T_3水平和脑组织神经颗粒素表达水平无明显影响。结论过量碘引起仔鼠脑神经颗粒素表达异常,补硒具有缓解作用。

Objective To study the effects of excess iodine intake on neurogranin expression in cerebrum of filial mice and the intervention of selenium. Methods Sixty BALB/c mice were divided randomly into four groups with different drinking water： control group （tap water, NC）, excess iodine group （3000 μg/LI, EI^ ＋ ）, supplementing selenium group （ 200 μg/L Se, Se ^＋ ） and the excess iodine plus selenium （3000 μg/L ＋ I 200 μg/L Se, EI ＋ Se ＋ ） group. The mice were mated at the end of the fourth month. Serum T4 and T3 were determined on postnatal day 14 and 28. The expression level of neurogranin in filial cerebrum was measured by immunohistochemistry and Western blot. Results Serum T4 level in EI （68.78 ± 11.10 nmol/L） ＋ was lower significantly than that in NC（ 100. 85 ± 11.47nmol/L） and EI ＋ Se ＋ （93.15 ± 12. 10 nmol/ L） on postnatal day 14. Western blot analysis showed that the relative level of neuroogranin in EI ＋ （0. 621 ±0. 041 ） was lower than that in NC （0. 841 ±0. 039）and EI ＋ Se ＋ （0. 781 ± 0.029 ） on postnatal day 14 （P 〈 0. 05 ）. No significant difference in serum T4 and neurogranin level between four groups on postnatal day 28. Conclusion Excess iodine intake might change the expression of neurogranin in filial cerebrum and the selenium supplementation might alleviate it.