Metabolism of Thyroxine in Larva of Rice Moth ( Corcyra cephalonica St.)

Abstract

Summary

The major excretory metabolite of thyroxine in the insect Corcyra cephalonica St. is iodide, though monoiodotyrosine and di-iodotyrosine are present in small amounts. In vitro experiments with homogenates of larval tissue have shown that an enzyme system capable of forming iodide from thyroxine is present only in tissues of larvae fed thyroxine-supplemented diets and not in those of larvae fed control diet alone. Activity of the enzyme is destroyed by boiling for 10-15 minutes.