EFFECT OF X IRRADIATION ON THE METABOLISM OF C14-GLUCOSE AND C14-FRUCTOSE IN RAT LIVER SLICES
The utilization of C14-glucose and C14-fructose in liver slices from normal rats and from rats exposed to 1000 r of whole-body X irradiation was studied. Liver slices prepared from normal rats were incubated with C14-glucose or C14-fructose in equivalent amounts and the incorporation of C14 into carbon dioxide, glycogen, and an ethanolic extract was determined. After the rats had been fasted 4 or 24 hours the amount of C14 incorporated into glycogen and carbon dioxide from C14-fructose was greater than that incorporated from C14-glucose but the total radioactivity in the ethanolic extracts was approximately the same for both hexoses. When liver slices prepared from normal and X-irradiated rats were incubated with C14-glucose or C14-fructose 4 or 24 hours after irradiation, the samples obtained from irradiated rats incorporated a greater amount of C14 into carbon dioxide, glycogen, and the ethanolic extract, with the exception of the 24-hour samples incubated in the presence of labelled glucose. In the latter instance incorporation into carbon dioxide fell below the normal value. The total C14 recovery from the three fractions was always higher in the X-irradiated samples than in the corresponding control samples. Further examination of the ethanolic extracts (amino acids, lactic acid, and origin area material) separated by paper partition chromatography revealed additional differences between the samples of liver from normal and X-irradiated rats in their ability to incorporate C14 from either labelled hexose. These differences were apparent in samples incubated either 4 or 24 hours after X irradiation of the animals.