不同碘营养状态对克汀大鼠脑内T_45′-和5-脱碘酶活性的影响  

Effects of various iodin-nutritional on activity of T_4 5′-and 5-deiodinase in rat brain

作　　者：郭善一[1] 左爱军[1] 刘年庆[2] 赵学勤[1] 郭若霖[3] 张芳[2] 张镜宇[1] 

机构地区：[1]天津医科大学内分泌研究所,300070 [2]中国科学院高能物理所 [3]天津骨科医院

出　　处：《中华预防医学杂志》2005年第1期30-32,共3页Chinese Journal of Preventive Medicine

基　　金：国家自然科学基金资助项目(19975055)

摘　　要：目的研究不同碘营养状态下克汀大鼠脑内T45′和5脱碘酶活性的变化。方法复制Wistar克汀大鼠,通过饮水中含碘量不同分为低碘组、适碘组、高碘组、正常对照组,每组2或3窝(31～42只),选用20d龄的仔鼠进行实验,测定4组动物模型甲状腺功能状态及脑T45′和5脱碘酶活性。结果低碘组TT4和FT4均低于正常对照组,均为正常对照组的35%,FT3高于正常对照组740%;适碘组TT4和FT4高于正常对照组145%和277%;高碘组TT4和FT4均低于正常对照组,仅为正常对照组的6186%和620%,TT3低于正常对照组,FT3显著高于正常对照组849%。低碘组脑组织中T45′脱碘酶活性相当于每克组织每小时(195±032)ngT3/μgT4,显著高于正常对照组(159±023),5脱碘酶活性相当于每克组织每小时(138±021)ngrT3/μgT4,低于正常对照组(202±026),高碘组T45′和5脱碘酶活性每克组织每小时(112±019)ngT3/μgT4和(173±036)ngrT3/μgT4,低于正常对照组。结论5′脱碘酶活性在低碘时活性升高,在高碘时活性降低;5脱碘酶在低碘和高碘时活性均降低。Objective To investigate the changing of T_4 5′-and 5-deiodinase within rat brain under various iodin-nutritional states.Methods Animal model of iodine-deficiency rat was performed and the rats were divided into 4 groups by the intake of iodine-nutrition,and then killed at an age of 20 days. The thyroid hormones level in serum was measured by ELISA and the activity of T_4 5′-and 5-deiodinase within brain was analyzed.Results In less-iodine(LI) group,TT_4 and FT_4 were accounting for 3.5% of the neutral-iodine(NI) group’s, and FT_3 was 174.0% of NI group’s (P<0.05). In NI group,TT_4 and FT_4 were 114.5% and 127.7% of NI group’s (P<0.05). In high-iodine(HI) group, TT_4 and FT_4 were 61.86% and 62.0% of NI group’s, and FT_3 was 184.9% of NI group’s (P<0.05). In LI group, the activity of T_4 5′-deiodinase tissue of per gram (1.95±0.32) ngT_3·μgT^-1 _4·h was significantly higher than that of NI group (P<0.05), and the activity of 5-deiodinase (1.38±0.21) ngrT_3·μg T^-1 _4·h^-1 is significantly less than that of NI group (1.59±0.23)(P<0.05). In HI group the activity of T_4 5′-and 5-deiodinase tissue of per gram (1.12±0.19 and 1.73±0.36) ngrT_3·μgT^-1 _4·h^-1 was significantly less than that of NI group (P<0.05).Conclusion The activity of T_4 5′-deiodinase in iodine deficiency heightens and that in iodine excess is debased, the activity of T_4 5-deiodinase in iodine deficiency and in iodine excess is debaseds.

关 键 词：对照组 正常 脱碘酶 低碘 高碘 大鼠 脑内 酶活性 饮水 仔鼠 

分 类 号：R151[医药卫生—营养与食品卫生学]