SERUM BINDING AND BILIARY CLEARANCE OF TRIIODOTHYRONINE IN COLD-ACCLIMATED RATS

Abstract

The more rapid biliary clearance of thyroid hormones resulting from cold acclimation in rats may be the result of an increased capacity of the liver to remove hormone from the blood and (or) to a decreased affinity of the hormone for thyroid-binding protein. The binding of labelled L-triiodothyronine to serum proteins of cold- and warm-acclimated rats has been compared in vitro. Less label was found to bind to protein in sera from cold-acclimated rats, which suggests that a decrease in affinity of thyroid hormones for the binding protein may contribute to the increased biliary clearance found.