Radiation Response of Mammalian Cells Grown in Culture: V. Temperature Dependence of the Repair of X-Ray Damage in Surviving Cells (Aerobic and Hypoxic)

Abstract

The temperature and oxygen dependence of the repair of sublethal X-ray damage in cultured mammalian cells has been examined. It was found that surviving cells can repair damage quite effectively at room temperature, and some repair is effected even at 1[degree]C. Also, the repair process does not require oxygen. Moreover, hypoxic cells can repair sublethal damage at room temperature. Since the ability of mammalian cells to grow and divide is strongly temperature dependent and repair of damage is not, from these results we have been able to show that the fractionated dose response of surviving cells at an optimal growth temperature consists of 2 simultaneous processes. Repair processes lead to a prompt increase in net survival. Cell progression processes lead to oscillations in net survival as cells undergoing repair move through response states of different sensitivities.