Jennings A S
Am J Physiol. 1984 Oct;247(4 Pt 1):E526-33. doi: 10.1152/ajpendo.1984.247.4.E526.
The effect of diabetes on 3,5,3'-triiodothyronine (T3) production was determined in the isolated perfused rat liver. Induction of diabetes with streptozotocin resulted in decreased serum thyroxine (T4) and T3 levels and a progressive decline in hepatic T3 production over 5 days. The decline in T3 production resulted from decreased conversion of T4 to T3, whereas T4 uptake was unchanged. Insulin administration restored serum T4 and T3, hepatic conversion of T4 to T3, and T3 production to normal levels. When serum T4 levels in diabetic rats were maintained by T4 administration, the conversion of T4 to T3 and T3 production returned to control levels. However, restoration of serum T4 levels in fasted rats failed to correct the decrease in hepatic T4 uptake or T3 production. Glucagon, at supraphysiological concentrations in vitro and in vivo, slightly decreased T4 uptake and T3 production without altering the conversion of T4 to T3. These data suggest that the fall in serum T4 levels observed in diabetic rats is important in mediating the decreased hepatic conversion of T4 to T3 and T3 production.
在离体灌注大鼠肝脏中测定糖尿病对3,5,3'-三碘甲状腺原氨酸（T3）生成的影响。用链脲佐菌素诱导糖尿病导致血清甲状腺素（T4）和T3水平降低，并且在5天内肝脏T3生成逐渐下降。T3生成的下降是由于T4向T3的转化减少，而T4摄取未改变。给予胰岛素可使血清T4和T3、肝脏T4向T3的转化以及T3生成恢复至正常水平。当通过给予T4维持糖尿病大鼠的血清T4水平时，T4向T3的转化以及T3生成恢复至对照水平。然而，在禁食大鼠中恢复血清T4水平未能纠正肝脏T4摄取或T3生成的减少。在体外和体内，超生理浓度的胰高血糖素可轻微降低T4摄取和T3生成，但不改变T4向T3的转化。这些数据表明，糖尿病大鼠中观察到的血清T4水平下降在介导肝脏T4向T3的转化减少以及T3生成减少中起重要作用。
