Abstract
Rat hepatoma cells (R117-21B) metabolized 3, 3'-diiodothyronine and 3'-monoiodothyronine by sulfation and glucuronidation. Glucuronidation of iodothyronines (a mixture of 3, 3'-diiodothyronine, -90%, and 3'-monoiodothyronine, -10%) was very rapid and 83% of the total 125I in the medium was their glucuronides after 8hr incubation with the cells at 37°C. Iodothyronine sulfates (-9% of the total 125I) were also detected. No clear increase in free iodide was observed during the 8 hr incubation.
The effect of KCN or dinitrophenol on glucuronidation of thyroxine was investigated. Both drugs inhibited glucuronidation, and dinitrophenol was more effective than KCN. Dinitrophenol accelerated the liberation of 1251-in the metabolism of thyroxine in the cultured rat hepatoma cells.
