高碘对大鼠大脑皮层神经细胞凋亡的诱导作用  

High Iodine Induces Apoptosis of Rat Cortical Neural Cells

作　　者：许颖[1] 岳丹[1] 张辉[1] 肖建英[1] 

机构地区：[1]辽宁医学院生物化学教研室,辽宁锦州121001

出　　处：《辽宁医学院学报》2007年第3期4-6,共3页Journal of Liaoning Medical University (LNMU) Bimonthly

基　　金：辽宁省教育厅(编号05L132);辽宁医学院大学生科技创新资助项目

摘　　要：目的观察长期高碘对大鼠皮层神经细胞凋亡的影响,并探讨其作用机制。方法断乳1月龄的SD大鼠随机分为三组,对照组、高碘Ⅰ组、高碘Ⅱ组,分别以含碘量为5μg/L、5000μg/L、10000μg/L的自来水及普通饲料喂养6个月,测定血清甲状腺激素(TT3、TT4)水平;透射电镜观察皮层神经元形态结构的改变;应用流式细胞仪检测细胞凋亡率及细胞周期的变化;采用比色法检测大鼠皮层神经细胞一氧化氮(NO)含量和一氧化氮合酶(n itric oxide synthase,NOS)的活性。结果与对照组比较,高碘Ⅰ组、高碘Ⅱ组的血清TT3、TT4呈逐渐下降趋势,但各组间差异无统计学意义(P>0.05)。超微结构观察,高碘组神经细胞核内染色质浓缩成块状,聚集在核膜边缘,形成新月状、马蹄状等不规则形态,核膜内陷、形成凋亡小体。流式细胞仪检测高碘组引起大鼠皮层神经细胞周期改变,细胞凋亡率明显高于对照组(P<0.01),同时高碘组NOS活性及NO含量显著降低,但两个高碘组之间无明显差异(P>0.05)。结论长期高碘可诱导大鼠皮层神经细胞损伤及凋亡,其机制可能与NOS活性及NO含量降低有关。Objective To study the apoptosis and the mechanism in rat cortical neural cells induced by high iodine and to detect the effect of this method. Methods An animal model of goiter was reconstructed in rat by feeding water containing different level of iodine for 6 months. Rats were randomly divided into three groups： control group, high iodine group Ⅰ and high iodine group Ⅱ. The changes of cortical neural cells as well as morphological and ultra structure were observed. The content of serum thyroid hormones was measured by using radio- immunoassay. The apoptosis rate and cell cycle in cortical neural cells were detected by flow cytometry. Content of nitric oxide （NO） and activity of nitric oxide synthase （NOS） were evaluated by spectrophotometry. Results The level of serum thyroid hormones was decreased gradually in high iodine group Ⅰ and high iodine group Ⅱ compared with the control group, but there were no remarkable differences among these three groups （P 〉 0. 05 ） . The morphologic damage was found in the high iodine group, and the apoptosis rate increased in cortical neural cells in high iodine group （P 〈0. 01 ） . Both the content of NO and the activity of NOS in the high iodine groups were lower than those of the control group, but there was no significant difference between high iodine group Ⅰ and high iodine group Ⅱ （ P 〉 0.05 ） . Conclusions High iodine may induce apoptosis in cortical neural cells, which may be related to the decrease in the NO contents and NOS activity.

关 键 词：高碘 大鼠 皮层神经细胞 细胞凋亡 

分 类 号：R339[医药卫生—人体生理学]