AEROBIC GLYCOLYSIS OF X-IRRADIATED THYMOCYTES

Abstract

The aerobic lactate production of rat thymocyte suspensions incubated at 37 °C for 2 hours was doubled following exposure to approximately 70 r X-radiation. Lower doses down to 18 r also produced a significant increase in aerobic lactate production. Increased lactate accumulation following exposure to 1000 r was observed after incubation for as little as 30–60 minutes, though the rate of accumulation increased still further between 2 and 4 hours incubation. A decrease in pH or temperature during incubation of irradiated thymocyte suspensions minimized the lactic acid accumulation. A comparison of the effects of X-irradiation in different media and of the effects of several metabolic inhibitors suggested that the increase in aerobic lactate production was a sensitive indicator of cell damage associated with the loss of intracellular potassium ions.Respiration and anaerobic glycolysis of the thymus cells were both much less sensitive than aerobic glycolysis to the effects of X-irradiation. The "anaerobic" lactate production of rat thymocyte suspensions in the presence of dinitrophenol was reduced by 50% after exposure to 5000–6000 r of X-radiation.