The Effect of Extreme Hypoxia and Glucose on the Repair of Potentially Lethal and Sublethal Radiation Damage by Mammalian Cells

Abstract

Confluent monolayers of Chinese hamster ovary cells repaired potentially lethal X-ray damage under aerobic conditions but did not repair damage under extremely hypoxic conditions. Addition of extra glucose to the medium allowed some repair of potentially lethal damage by hypoxic cells. Because of the effect of glucose, earlier experiments were repeated, which showed that exponentially growing cells did not repair sublethal damage under extremely hypoxic conditions using both plateau-phase and exponentially growing cells. Under extremely hypoxic conditions, no repair of sublethal damage was observed, even at high glucose concentrations. Under aerobic conditions, plateau-phase cells repaired sublethal damage more rapidly and more efficiently than did similarly treated exponentially growing cells. The O2 and/or energy requirements were different for the repair of potentially lethal and sublethal damage.