Thyroxine-Serum Protein Complexes in Various Animals

Abstract

Thyroxine-protein interactions in a variety of vertebrate species of the Classes Mammalia, Aves, Reptilia, Amphibia and Pisces have been studied by electrophoresis in filter paper and starch gel. It has been found that a specific thyroxine-binding alphaglobulin occurs only in mammals. All other vertebrates probably have proteins capable of binding thyroxine less strongly. Intraspecies genetic variability in thyroxine-binding patterns may occur. Each animal should be investigated thoroughly by a variety of methods in order to comprehend fully the thyroxinebinding capabilities of its serum proteins.