Influence of Thyroxine on the Metabolism of Ethanol and Glycerol in Rat Liver Slices

1 The rates of ethanol oxidation by liver slices from L-thyroxine treated, methyl-thiouracil fed, and thyroidectomized rats were not significantly different from those of livers from normal animals. 2 The production of lactate and pyruvate in the presence of ethanol was lower in liver slices from thyroxine treated rats than in liver from normal and hypothyroid animals. The lactate/pyruvate ratio was not changed in hyperthyroid animals, but increased in hypothyroid rats. 3 The rate of glycerol utilization by liver slices from normal and hypothyroid rats was inhibited about 50% in the presence of ethanol. This inhibition was not observed in thyroxine treated rats. 4 The concentration of α-glycerophosphate in liver slices incubated for 60 minutes was low in thyroxine treated rats and significantly higher in hypothyroid rat livers. Addition of ethanol increased the concentration of α-glycerophosphate in liver slices to about twice the control values without ethanol in all groups of rats. Addition of ethanol and glycerol together caused very high concentrations of α-glycerophosphate in normal and hypothyroid but not in thyroxine treated animals. 5 The glycerokinase activity of the liver did not change significantly after administration of thyroxine or thyroidectomy.