Changes in Energy Metabolism Following Roentgen Irradiation of in Vivo Growing Ehrlich Ascites Tumour Cells Studied by 31P Magnetic Resonance Spectroscopy

The energy metabolism in Ehrlich ascites tumour cells following in vivo irradiation of a dose of 5.0 Gy was studied in vitro in their ascites fluid up to 48 hours using ³¹P magnetic resonance spectroscopy measuring ATP, ADP and inorganic phosphate (P_i). The results are also related to radiation induced changes in cell cycle composition. ATP was reduced by more than 50 per cent 20 to 24 hours after irradiation but normalized at 48 hours. ADP was reduced to about half the normal level 24 to 48 hours' after irradiation. When the ATP and ADP had reduced levels, the inorganic phosphate increased correspondingly. Addition of glucose to the ascites cell suspension at the time of minimum ATP level immediately raised the ATP: P, ratio. Since the glucose concentrations in blood and in ascites fluid following irradiation were also reduced, lack of glucose for energy production might have been a major contributing factor for the reduced ATP production.