Effects of L-thyroxine on the intermediary metabolism of the Spotted Munia, Lonchura punctulata

Abstract

L-Thyroxine was injected over a period of 1 mo into Spotted Munia, Lonchura punctulata, and the following variables were measured: glucose and protein in the plasma, glycogen in the muscle and liver, cholesterol and fatty acid esters in the liver, and plasma, and free fatty acids and triglycerides in the liver, plasma, and adipose tissue. The hormone had different effects at different dose levels on the plasma proteins, liver free fatty acids, and plasma and liver fatty acid esters. It caused significant decrease in hepatic glycogen and triglycerides and significant increase in the plasma and adipose tissue free fatty acids. Low and high doses decreased significantly plasma triglycerides and muscle glycogen, respectively, and the mid dose decreased plasma glucose and adipose triglycerides. Hepatic and plasma cholesterol was not affected significantly. © 1975.