内毒素血症小鼠肝脏1型脱碘酶与3型脱碘酶表达水平及活性变化

Changes of iodothyronine deiodinase type 1 and type 3 mRNA level and activity in liver of mice with endotoxemia

目的 探讨内毒素血症对三碘甲状腺原氨酸（T3）、甲状腺素（T4）及1型脱碘酶（D1）与3型脱碘酶（D3）mRNA水平及活性的影响。方法 将16只SPF级成年昆明种小鼠随机分为对照组和脂多糖（LPS）组，每组8只。LPS组小鼠复制内毒素血症模型。2组动物取股动脉血，放射免疫分析法检测其血清T3、T4；取肝脏组织，实时荧光定量聚合酶链反应法测其肝脏 D1及 D3 mRNA 表达水平，离子交换层析法结合放射性底物分析法测其肝脏D1及D3活性。数据采用SPSS13.0统计软件进行分析。结果 2组小鼠血清 T3水平、D1与D3 mRNA相对表达水平及活性比较差异均有统计学意义（P均 〈0.01），T4水平的差异无统计学意义（P 〉0.05）。结论 内毒素血症可并发正常甲状腺病态综合征，D1与 D3 mRNA表达水平与活性的变化是其可能的影响因素。

Objective To explore the effect of endotoxemia on triiodothyronine （ Ta ） and thyroxine （ T4 ）, and the level and activity of iodothyronine deiodinase type 1 and type 3 mRNA. Methods Sixteen mice were randomly divided into control group and lipopolysaccharide （LPS） group, with 8 mice in each group. The mouse model of endotoxemia was replicated in the LPS group. In the both groups, blood samples from femoral week were collected to assay T3 and T4 levels,and the livers were sampled to inspect D1 and D3 mRNA levels and activities. Serum T3 and T4 levels were assayed with radioimmunoassay,D1 and D3 mRNA levels in liver were detected with real-time polymerase chain reaction, the activity of D1 and D3 in liver were measured by using ion-exchange chromatography combined with immunoassay. The data were statistically analyzed by SPSS 13.0 software. Results Statistical differences of T3 , D1 and D3 mRNA levels and activities between the 2 groups were found （all P 〈 0.01 ） ,while, there was no statistic difference in the statuses of T4 （P 〉 0.05 ）. Conclusions It is possible that euthyroid sick syndromes happens in endotoxemia episodes,and the changes of D1 and D3 mRNA levels and activities are the possible influencing factors.