Protection of mice from whole body gamma irradiation by deuteration of drinking water: hematologic findings.

Partial deuteration of mice by ingestion of 29% heavy water for 12 days prior to irradiation lessened their susceptibility to lethal doses of whole body gamma irradiation from a 60Co source. Deuteration alone slightly reduced the number of nucleated bone marrow cells, blood leukocytes, and platelets. After exposure to 8.5 Gy, all mice drank tap water. Radiation-induced destruction of hemopoietic and lymphoid tissues was of equal degree in deuterated and control animals. Conversely, nucleated bone marrow cells, blood leukocytes and platelets, endogenous spleen colonies, and thymus of deuterated mice displayed signs of an accelerated and/or enhanced regeneration. The cytokinetic changes observed in deuterated animals were consistent with a protective effect for pluripotent stem cells at the time of irradiation.