THE EFFECTS OF EPINEPHRINE ON THYROXINE METABOLISM: CHROMATOGRAPHIC STUDIES OF SERUM AND TISSUE EXTRACTS

Abstract

Labeled thyroxine was administered to humans and rats with and without the simultaneous administration of epinephrine. Epinephrine produced a decrease in the level of serum protein-bound iodine in humans. Chromatographic analysis of butanol extracts of serum and tissue was performed. Metabolites of thyroxine accumulated in the serum of some control subjects but not in the serum of those given epinephrine. Epinephrine did not produce an increase in thyroxine-derived triiodothyronine during the time in which it exerts a calorigenic effect. The data do not support the hypothesis that thyroxine must be deiodinated to triiodothyronine prior to entry into the peripheral tissues or during the course of hormonal activity.