The Effect of Ionizing Radiation on Telomere Homeostasis in Peripheral Blood

Objective To investigate the effects of ionizing radiation exposure on telomere length in both mice and humans, as well as on telomerase activity in mice, so as to provide a theoretical basis for the protection of occupational exposure populations.Methods Whole blood samples were collected from mice and humans to measure average telomere length and telomerase activity.Results In mice, both telomere length and telomerase activity decreased shortly after irradiation but began to recover after 24 hours. Under radiation doses of 0.25Gy~2Gy, telomere length exhibited a time-dependent "U-shaped" change. At doses of 0.5Gy~2Gy, telomerase activity showed dynamic fluctuations: an initial decrease followed by a rebound, with a transient peak observed at 4 hours. In humans, exposure to 1Gy of radiation resulted in a short-term increase in telomere length (Z=-3.432, P=0.001).Conclusions Telomere elongation in mice after irradiation is primarily mediated by telomerase. Dynamic monitoring of telomerase activity (e.g., the 4-hour peak) may serve as an early biomarker for ionizing radiation exposure.