中文摘要：

建立亚临床甲状腺功能减退（SCH）大鼠模型，分为SCH组、左旋甲状腺素（L-T4）治疗组和对照组。L-T4治疗组总胆固醇和内皮素水平低于SCH组，差异有统计学意义[（1.29±0.05对2.38±0.55） mmol/L，（98.54±32.43对160.62±37.25） nmol/L，均P〈0.05]。与SCH组相比，L-T4治疗组一氧化氮、左心室收缩压和腹主动脉血流均升高（P〈0.05）。提示L-T4 可以改善SCH的内皮功能及血流动力学改变。

英文摘要：

Established rat models with subclinical hypothyroidism （SCH） were divided into three groups： subclinical hypothyroid （ SCH）, SCH treated with levothyroxine （ L-T4 ）, and control group. The L-T4 group displayed lowered total cholesterol and endothelin levels compared with the SCH group [ （ 0. 29 ±0. 05 vs 2.38 ± 0.55 ） mmol/L, （98.54 ± 32.43 vs 160.62 ± 37.25 ） nmol/L, both P〈0.05 ]. Nitric oxide levels, left ventricular systolic pressure, and blood flow in abdominal aorta were significantly higher in the L-T4 group than those in the SCH group. The results of this study indicate that L-T4 treatment may improve endothelial dysfunction and hemodynamic changes in rats with SCH.