The Influence of Liver Damage in Man on the Distribution and Disposal Rates of Thyroxine and Triiodothyronine

Abstract

Simultaneous studies of thyroxine (T4) and tri-iodothyronine (T3) kinetics were carried out in a group of patients suffering from severe cirrhosis with ascites and a group of normal persons. In comparison with the normal group, the cirrhotic patients were found to have reduced T4 volumes of distribution and T4 production rates; conversely, the percent and absolute quantities of free T4 were elevated. The free serum T3 values were elevated in the cirrhotic group, and the T3 volumes of distribution and T3 production rates were likewise elevated. The mean TBG capacity in the cirrhotic patients was significantly increased, and there was a marked reduction in TBPA capacity. A single simple explanation cannot be found to account for these diverse findings. Probably alterations of a number of parameters are involved, including reduction in TBPA capacity, reduction in hepatic thyroid hormone binding sites, and relative competition of tissue binding sites for T4 and T3. The findings suggest that the liver is norma...