Development of evaluation method for the radiation effects on the metabolisms of essential elements as an indicator and protection from radiation

Aiming to investigate the effects of radiation in cellular level, incorporation of labelled essential elements, 59Fe and 58Co were investigated using mice exposed to X-ray (0.5-5 Gy). The cells of immune system and hematopoietic cells, which are highly sensitive to radiation were chosen since their cellular activities such as DNA synthesizing ability can be determined concomitantly. Although DNA synthesis was decreased in the spleen cells after exposure to X-ray, 58Co incorporation was increased when exposed at a dose more than 1 Gy regardless of the presence of mitogenic stimulation. However, a clear dose-response relationship for Fe incorporation was not observed. In the bone marrow cells, 58Co incorporation showed similar tendency to those in the spleen cells, whereas 59Fe incorporation was decreased as a dose increase in the presence of GM-CSF. These reduced incorporations due to X-ray radiation were recovered from near 7 days after the radiation. The time course changes in radiation effects on 58Co incorporation were similar to those for 3H-thymidine. (M.N.)