Effects from Chronic Restraint-Induced Stress and Total Body Fe Irradiation on the Hematopoietic System in Trp53-Heterozygous Mice.

Both ionizing radiation (IR) and psychological stresses (PS) cause detrimental effects on humans. A pioneering study showed chronic restraint-induced PS (CRIPS) increased gamma-radiation-induced carcinogenesis in Trp53+/- mice. Prior to carcinogenesis study, to investigate the effects from PS on IR-induced health consequences, effects of Fe total body irradiation (Fe TBI) on the hematopoietic system in Trp53+/- mice under CRIPS were studied. Six-week-old male C57BL/6N mice were chronically restrained 6 hours daily for consecutive 28 days, being given Fe TBI (0.1 Gy or 2.0 Gy) on the 8th day. The peripheral blood and the bone marrow were collected for analysis of hematological abnormality and residual damage in the erythrocytes. Results showed that concurrent exposure of the animals to CRIPS and Fe TBI always showed a tendency of increased micronucleated erythrocytes when compared to the animals receiving only Fe TBI, and the increase was statistically significant for the mice receiving Fe TBI at 0.1 Gy. This work was partially supported by MEXT Grant-in-Aid for Scientific Research on Innovative Areas, “Living in Space” (JP15K21745, 15H05944 and 5H05935).日本宇宙生物科学会第33回大会