Sulfation preceding deiodination of iodothyronines in rat hepatocytes

In man and animals iodothyronines are metabolized by deiodination and conjugation with glucuronic acid or sulfate. Until now these processes have been regarded as independent reactions. However, in the present study a close interaction of these pathways was observed in the hepatic metabolism of 3,3'-diiodothyronine and 3,3',5-triiodothyronine. Studies with rat hepatocytes and liver microsomes indicated that sulfation of the phenolic hydroxyl group facilitates the deiodination of these compounds.