Sorimachi K, Niwa A, Yasumura Y
Biochim Biophys Acta. 1980 Nov 17;633(1):134-43. doi: 10.1016/0304-4165(80)90045-8.
The metabolism of thyroxine, 3,3'-triiodothyronine and 3,3',5'-triiodothyronine was investigated in rat hepatoma cell cultures (R117-21B). These iodothyronines were labeled with 125I in the phenolic ring and the metabolites were analyzed by ion-exchange column chromatography. When thyroxine was incubated with the cells at 37 degrees C, its glucuronide was the major product and a little increase in 125I- was detected. Although 3,3',5-triiodothyronine was not observed in the incubation medium, this metabolite was clearly identified in the ethanol extract obtained from the cell homogenates after 24 h incubation. This cell line also metabolized labeled 3,3',5-triiodothyronine added to culture medium. After 24 h incubation, 3,3',5-triiodothyronine glucuronide was the major metabolite and iodothyronine sulfates were also formed. The sulfates contained, 3,3',5-triiodothyronine and 3,3'-diiodothyronine sulfates and an unknown component. In the metabolism of 3,3',5'-triiodothyronine, the cells were very active in carrying out glucuronidation and phenolic ring deiodination, and this metabolism yielded 3,3',5'-triiodothyronine and 3,3'-diiodothyronine glucuronides. The iodide fraction contained a small amount of 3,3'-diiodothyronine sulfate. These results show that the R117-21B rat hepatoma cells metabolize the thyroid hormones and their analogs by phenolic and nonphenolic ring deiodinations, by glucuronidation and by sulfation.
在大鼠肝癌细胞培养物（R117 - 21B）中研究了甲状腺素、3,3'-三碘甲状腺原氨酸和3,3',5'-三碘甲状腺原氨酸的代谢情况。这些碘甲状腺原氨酸在酚环上用125I进行标记，代谢产物通过离子交换柱色谱法进行分析。当甲状腺素在37℃与细胞一起孵育时，其葡萄糖醛酸苷是主要产物，并且检测到125I-略有增加。虽然在孵育培养基中未观察到3,3',5-三碘甲状腺原氨酸，但在孵育24小时后从细胞匀浆获得的乙醇提取物中明确鉴定出了这种代谢产物。该细胞系还能代谢添加到培养基中的标记3,3',5-三碘甲状腺原氨酸。孵育24小时后，3,3',5-三碘甲状腺原氨酸葡萄糖醛酸苷是主要代谢产物，同时也形成了碘甲状腺原氨酸硫酸盐。这些硫酸盐包含3,3',5-三碘甲状腺原氨酸和3,3'-二碘甲状腺原氨酸硫酸盐以及一种未知成分。在3,3',5'-三碘甲状腺原氨酸的代谢过程中，细胞在进行葡萄糖醛酸化和酚环脱碘反应方面非常活跃，这种代谢产生了3,3',5'-三碘甲状腺原氨酸和3,3'-二碘甲状腺原氨酸葡萄糖醛酸苷。碘化物部分含有少量的3,3'-二碘甲状腺原氨酸硫酸盐。这些结果表明，R117 - 21B大鼠肝癌细胞通过酚环和非酚环脱碘、葡萄糖醛酸化和硫酸化作用来代谢甲状腺激素及其类似物。
