Grussendorf M, Hüfner M
Clin Chim Acta. 1977 Oct 1;80(1):61-6. doi: 10.1016/0009-8981(77)90264-9.
In thyroidectomized, unsubstituted rats the T4 to T3 converting activity of liver homogenate is reduced to about 30% of that in unoperated control animals. The enzyme activity can be reinduced dose-dependently with T4. To achieve a normal activity, high, non-physiological plasma T4 concentrations are needed. Plasma T3 levels are much better correlated to the T4 to T3 converting activity. Pure T3 proved to be a more potent enzyme inducer than T4. No difference could be detected between L- and D-T3. Tyrosine, diiodotyrosine, 3,3'-diiodothyronine and 3,3',5'-T3 (reverse-T3) showed no inductive effect for the enzyme. These results demonstrate that the T4 to T3 converting enzyme is specific and shows regulatory properties.
在甲状腺切除且未进行替代治疗的大鼠中，肝脏匀浆的T4向T3转化活性降至未手术对照动物的约30%。该酶活性可被T4剂量依赖性地重新诱导。为达到正常活性，需要高的、非生理性的血浆T4浓度。血浆T3水平与T4向T3转化活性的相关性更好。纯T3被证明是比T4更有效的酶诱导剂。L-T3和D-T3之间未检测到差异。酪氨酸、二碘酪氨酸、3,3'-二碘甲状腺原氨酸和3,3',5'-T3（反式T3）对该酶无诱导作用。这些结果表明，T4向T3转化酶具有特异性并表现出调节特性。
