高碘对豚鼠脑和甲状腺细胞凋亡及调节基因表达的影响  

Effects of excessive iodine on apoptosis and expression of bcl-2、bax genes in the cells of brain and thyroid gland in guinea pigs

作　　者：杨长春[1] 尹桂山[1] 崔灵光 朱惠民 左连富[3] 

机构地区：[1]石家庄市河北医科大学生化教研室,050017 [2]公共卫生学院 [3]河北省肿瘤研究所

出　　处：《中华预防医学杂志》2000年第2期95-97,共3页Chinese Journal of Preventive Medicine

摘　　要：目的　探讨高碘对脑和甲状腺细胞凋亡及bcl 2、bax基因表达的影响。方法　分别以含碘量为 5 0 μg/L(适碘组 )和10 0 0 0 μg/L(高碘组 )的蒸馏水喂养两个实验组的豚鼠 6个月 ,应用流式细胞术和免疫荧光技术检测豚鼠大脑皮质、海马和甲状腺细胞凋亡率 ,并对bcl 2、bax基因蛋白表达进行定量检测。结果　高碘组大脑皮质、海马和甲状腺细胞凋亡率明显高于适碘组 ;高碘组大脑皮质、海马和甲状腺组织bcl 2蛋白表达量较适碘组明显降低 ,而bax蛋白表达量则明显高于适碘组 ;高碘组大脑皮质、海马和甲状腺组织bcl 2 /bax比值较适碘组明显降低。结论　高碘可以诱发大脑皮质、海马和甲状腺细胞凋亡 ,bax基因过度表达和bcl 2基因表达下调以及由此引起的bcl 2 /bax比值降低可能在高碘诱发脑和甲状腺细胞凋亡过程中起重要作用。Objective To investigate the effects of excessive iodine intake on apoptosis and the expression of bcl 2、bax genes in the cells of brain and thyroid gland. Methods Guinea pigs, divided into two groups at random, were fed with distilled water containing iodine 50 μg/L (a control group with appropriate iodine) and 10 000 μg/L (a trial group with excessive iodine), respectively for six months. Apoptosis rate and expression of bcl 2、bax gene in the cells of cerebral cortex、hippocampus and thyroid gland in guinea pigs were quantitatively determined by flow cytometry and immunofluorescent techniques. Results The proportion of apoptosis in the cells of cerebral cortex, hippocampus and thyroid gland was significantly higher in the group with excessive iodine intake than that in the control one ( P< 0 01). The level of expression of bcl 2 gene was notably decreased ( P< 0 05), but that of bax was notably increased ( P< 0 01), in the cerebral cortex, hippocampus and thyroid gland in the group with excessive iodine than in the control one. The ratio of bcl 2 to bax in the cerebral cortex, hippocampus and thyroid gland of the group with excessive iodine was decreased significantly ( P< 0 01) than that of the control one. Conclusion Excessive iodine intake may induce apoptosis in the cells of cerebral cortex、hippocampus and thyroid gland. The over expression of bax gene and the down regulation of bcl 2, which can then cause the decrease in a ratio of bcl 2 to bax, appear to play an important role in the course of apoptosis induced by excessive iodine intake.

关 键 词：脑 甲状腺 基因表达 高碘 细胞凋亡 

分 类 号：R329.2[医药卫生—人体解剖和组织胚胎学]