Effect of Preirradiation with Low Dose ¹²C⁶⁺ Ions on Cell Cycle Progression and DNA Damage in Mouse Thymus and Spleen

Key words: 
• low dose 12C6+ ion /
• preirradiation /
• cell cycle /
• DNA damage

Abstract: To investigate the effect of low dose ¹²C⁶⁺ preirradiation on the cell cycle progression and DNA damage in mouse thymus and spleen， KunMing strain mice were wholebody irradiated with 0， 0.05， 0.1， 0.25 or 0.5 Gy of 12C6+ ions as the preexposure dose， and were then irradiated with 4 Gy of 12C6+ ions as a challenging dose at 4 h after perexposure. At 12h after irradiation， cell cycles of thymus and spleen were analyzed by FACS， and the frequencies of cells with tail moment and the tail lengths were determined by the single cell gel electrophoresis. The results showed that compared with highdose exposure group， the percentages of S phase cells on thymus and the percentages of G0/G1 phase cells on spleen significantly decreased via pre exposure to lowdose ¹²C⁶⁺ ions. Moreover， the lowdose preexposure significantly reduced length of the tails and the number of cells with tail， especially at the 0.1 Gy preexposure. The data suggested that preexposure to lowdose heavy ion can alleviate S phase arrest in thymus cells and the G1 phase arrest in spleen cell， and the degree of DNA damage.