Rutgers M, Heusdens F A, Bonthuis F, Rooda S J, Visser T J
Department of Internal Medicine, Erasmus University Medical School, Rotterdam, The Netherlands.
Endocrinology. 1990 Oct;127(4):1617-24. doi: 10.1210/endo-127-4-1617.
The sulfate conjugate 3, [3'-125I] diiodothyroacetic acid (3,3'-TA2S) was discovered in plasma, and occasionally in bile, of 6-propyl-2-thiouracil-treated rats after administration of [125I]T3. The identification of this T3 metabolite was based on the following evidence: 1) the compound co-eluted in two different HPLC systems with synthetic 3,3'-TA2S; 2) its chromatographic behavior on Sephadex LH-20 was characteristic for a conjugated iodothyronine derivative; and 3) the metabolite was hydrolyzed by arylsulfatase and the liberated product comigrated with synthetic 3,3'-TA2 on HPLC. Marked accumulation of 3,3'-TA2S was observed only in rats with impaired type I deidodinase activity but not in controls. Furthermore, plasma and biliary 3,3'-TA2S levels varied with the experimental conditions such as anesthesia, i.e. both were increased in ketamine-anesthetized over pentobarbital-anesthetized animals. It was not possible to indicate the exact pathway through which 3,3'-TA2S is generated from T3; neither is it known how much of T3 is actually metabolized via 3,3'-TA2S. However, the significant plasma 3,3'-TA2S levels, even in unanesthetized animals, illustrate the physiological relevance of this T3 metabolite.
在给用6-丙基-2-硫脲嘧啶处理的大鼠注射[125I]T3后，在其血浆中发现了硫酸结合物3, [3'-125I]二碘甲状腺乙酸（3,3'-TA2S），偶尔在胆汁中也能发现。这种T3代谢物的鉴定基于以下证据：1）该化合物在两种不同的高效液相色谱（HPLC）系统中与合成的3,3'-TA2S共洗脱；2）其在葡聚糖凝胶LH-20上的色谱行为是结合型碘甲状腺原氨酸衍生物的特征；3）该代谢物被芳基硫酸酯酶水解，释放出的产物在HPLC上与合成的3,3'-TA2共迁移。仅在I型脱碘酶活性受损的大鼠中观察到3,3'-TA2S的显著积累，而在对照组中未观察到。此外，血浆和胆汁中3,3'-TA2S的水平随实验条件（如麻醉）而变化，即氯胺酮麻醉的动物中两者均高于戊巴比妥麻醉的动物。无法指出3,3'-TA2S从T3产生的确切途径；也不知道有多少T3实际上是通过3,3'-TA2S代谢的。然而，即使在未麻醉的动物中，血浆中3,3'-TA2S的显著水平也说明了这种T3代谢物的生理相关性。
