Triiodothyronine in Feces of Rats Fed Low Iodine Diet

Abstract

Summary

The present data, and those of Heninger and Albright (1), suggest that in rats fed a severely low iodine diet, T₃ may be released from the thyroid faster than T₄. The thyroids contained less than 2 times more T₃ than T₄ but the bile contained an average of 7 times more T₃ than T₄ and the feces averaged 4 to 11 times more T₃ than T₄. These data suggest that there may be a rapid conversion of T₄ to T₃ in the body or there may be T₃ synthesis in stimulated thyroids, independent of T₄ synthesis.