Metabolism of Glucose and Fructose in Liver of the Rat Subjected to Whole-Body X-Irradiation

¹ From the Department of Physiology, University of California School of Medicine, Berkeley, California

Metabolism of glucose and fructose in the liver of the rat exposed to 1,000 r of whole-body x-irradiation was studied. Liver slices prepared from normal rats and from irradiated rats were incubated with C¹⁴-glucose and C¹⁴-fructose, and the conversion of the C¹⁴ to CO₂, glycogen and fatty acids was measured. The recoveries of C¹⁴ in these products from the labeled glucose were greatly reduced in the experiments carried out 24, 48 and 72 hours after irradiation. The C¹⁴ recoveries in the corresponding experiments with C¹⁴-fructose were in the normal range. A single intravenous injection of glucose on the 3rd day after the irradiation was followed by no increase in liver glycogen. The same treatment with fructose doubled the glycogen content of the liver. The continuous intravenous administration of glucose, begun immediately after the irradiation and maintained for 3 days, resulted in liver glycogen values of 0.7–1.9%. The same course of treatment with fructose resulted in glycogen values of 4.2–5.0%. Fasting was ruled out as an explanation of the defective glucose utilization observed in the liver of the irradiated rat. Possible sites of action of ionizing radiations on the paths of hexose metabolism are discussed.