Tissue glycogen and blood glucose in irradiated rats. I. Effects of a single lethal x-irradiation

Fed and starved (overnight) male rats of the Wistar strains were exposed to wholebody irradiation with 14.35 Gy (1 500 R) of X-rays. After irradiation and sham-irradiation all animals were starved up to the examination performed 1, 6, 24, 48 and 72 h after the treatment. Concentration of glucose in the blood and concentration of glycogen in the liver, heart, skeletal muscle, brown and white adipose tissue were determined. Concentration of blood glucose and liver glucogen was found to increase between 1 and 6 h after irradiation of the starved animals. The most pronounced increase of glycogen concentration in the liver and heart muscle was observed 24 and 48 h after irradiation. The fed and starved irradiated rats reacted differently particularly between 48 and 72 h, when the liver glycogen concentration decreased in the fed animals and remained elevated in the starved ones. Very high values of terminal glycemia were observed in both groups. Accumulation of glycogen in the heart muscle indicates that this organ is sensitive to ionizing radiation.