THE RESPONSE TO THYROXINE AFTER SUBTOTAL HEPATECTOMY1

Abstract

The authors attempted to clarify the function of the liver in thyroxine metabolism, and, particularly, the assay of hormonal activity in animals in which decomposition or excretion of administered thyroid hormone was influenced by subtotal hepatectomy or ligation of the bile duct. Five different expts. were performed on rats as follows: Expt. 1. Group A-thyroidectomized.; group B-thyroidectomized, hepatectomized; group C-thyroidecto-mized, thyroxine-treated; group D-thyroidectomized, hepatectomized, thyroxine-treated. Expt. 2. Group A-normal controls; group B-hepatectomized. Expt. 3. Group A-thyroidectomized, thyroxine-treated; group B-thyroidectomized, bile-duct dilated, thyroxine-treated. Expt. 4. Group A-thyroidectomized, thyroxine-treated; group B-thyroidectomized, hepatectomized, thyroxine-treated. This expt. was essentially the same as expt. 1, with the exception that the thyroxine dosage was reduced to 2 daily subcut. injns. of 2.5 ug. Expt. 5. Group A-thyroidectomized, thyrotropin-treated; group B-normal, thyrotropin-treated; group C-hepatectomized, thyrotropin-treated. Thyroxine activity was greatly intensified in the absence of the liver. The liver did not play a significant role when the amt. of circulating thyroxine was within physiologic limits. The liver deals with excessive hormone by some process of inactivation and not by simple excretion.