Rezvani I, DiGeorge A M, Dowshen S A, Bourdony C J
Pediatr Res. 1981 Jan;15(1):6-9. doi: 10.1203/00006450-198101000-00002.
To study the action of human growth hormone (hGH) on peripheral metabolism of serum thyroxine (T4), an oral loading dose of levothyroxine (1.2 mg/m2) was administered to seven children with hypopituitarism before initiation of hGH therapy. Serum concentrations of triiodothyronine (T3), T4, reverse triiodothyronine (rT3), and thyroxine-binding globulin (TBG) capacity were measured sequentially for 6 days. The study was repeated after 4 wk of treatment with hGH. Serum concentrations of T4 were not affected by hGH therapy. In contrast, mean basal serum concentration of T3 increased significantly after treatment with hGH. Also, changes in serum concentrations of T3 and in the ratio of T3/T4 after an oral dose of levothyroxine were significantly augmented during hGH therapy. Serum concentrations of rT3 changed in the opposite direction of T3 during therapy. After treatment with hGH, the mean basal level of serum rT3 decreased, and increases in serum concentrations of rT3 after oral levothyroxine were significantly attenuated. No changes in mean serum concentrations of thyroid stimulating hormone (TSH) and TBG capacity were observed. These data suggest that administration of hGH to children with hypopituitarism enhances the extrathyroidal conversion of T4 to T3 and concomitantly decreases the serum concentration of rT3.
为研究人生长激素（hGH）对血清甲状腺素（T4）外周代谢的作用，在开始hGH治疗前，对7名垂体功能减退的儿童给予口服左甲状腺素负荷剂量（1.2 mg/m²）。连续6天依次测量血清三碘甲状腺原氨酸（T3）、T4、反三碘甲状腺原氨酸（rT3）和甲状腺素结合球蛋白（TBG）容量。在hGH治疗4周后重复该研究。hGH治疗未影响T4的血清浓度。相反，hGH治疗后T3的平均基础血清浓度显著升高。此外，口服左甲状腺素后T3的血清浓度变化及T3/T4比值在hGH治疗期间显著增大。治疗期间rT3的血清浓度变化与T3相反。hGH治疗后，血清rT3的平均基础水平降低，口服左甲状腺素后rT3的血清浓度升高显著减弱。未观察到促甲状腺激素（TSH）和TBG容量的平均血清浓度变化。这些数据表明，对垂体功能减退的儿童给予hGH可增强T4向T3的甲状腺外转化，并同时降低血清rT3浓度。
