抄録
One of the mechanisms of radiation-induced reoxygenation is a decrease in oxygen consumption of irradiated tumor tissues. In our previous study, we have reported that the cellular oxygen consumption rate in both L5178Y and M10 cells (a radiosensitive mutant of L5178Y) increased shortly after both X rays and 80 keV/µm carbon ions irradiation, and then returned to the value before irradiation. The time of occurrence of peak oxygen consumption for L5178Y and M10 was 24 hours after irradiation, and was independent of radiation quality and dose. In the present study, we measured the oxygen consumption rate in mouse lymphomas at 24 hours after X rays and carbon ions irradiation to investigate the dose dependency and the LET dependency of the cellular oxygen consumption rate. The peak oxygen consumption in both L5178Y and M10 at 24 hours after irradiation increased as dose increases to 20 Gy of X rays and carbon ions. The peak oxygen consumption in M10 was about 300% of controls, and was higher than that in L5178Y. The oxygen consumption in L5178Y at 24 hours after carbon ion irradiation increased as LET increases from 20 to 80 keV/µm.
