Protection of mice from whole-body gamma radiation by deuteration of drinking water

Drinking water made available to mice was changed from ordinary tap water to tap water containing 30 atom% D2O when the animals were 6 to 8 weeks old. Twelve days later, the deuterated mice and an approximately equal number of nondeuterated control mice were subjected to whole-body gamma radiation from a 60Co source. All mice received ordinary tap water after the irradiation. Postirradiation mortality was significantly less in deuterated than in nondeuterated animals. These results may have practical implications for radiotherapy of human malignant tumors.