RELEASE OF THYROXINE FROM THE LIVER DURING ANAESTHESIA AND SURGERY

During relatively minor surgical procedures under halothane anaesthesia, an increase in plasma protein-bound iodine concentration was observed. In patients previously given thyroxine labelled with radio-iodine, plasma radioactivity concentrations also increased. There was a concomitant decrease in radioactivity in the liver. The results suggest that anaesthesia leads to a progressive discharge of protein-bound thyroxine from the liver into the plasma. The effect is believed to be reversible.