Effect of Ethanol and Linoleic Acid on Changes in Biliary Excretion of Iodothyronines Possibly Related to Thyroxine Deiodination in Rat Liver

Summary

Groups of male rats weighing about 350 g were inserted polyethylene tubings into bile duct and femoral vein under pentobarbital anesthesia. Several iodothyronines (i.e. T₄, T₃, rT₃, 3,5-T₂, 3,3′-T₂ and 3′,5′-T₂) were estimated in 2-hr portions of bile with the aid of specific radioimmunoassay. After the infusion of ethanol significant increase of 3′,5′-T₂ excretion was found. It was concluded that both ethanol and unsaturated fatty acids may inhibit 5′-monodeiodination in the liver and that unsaturated nonesterified fatty acids may exert such effect even when administered intravenously without underlying metabolic disorders.

Key-Words

Liver - Thyroxine Metabolism - Bile - Ethanol - Nonesterified Fatty Acids