Abstract: This paper is to explore effects of ¹²C ions beam exposure on cell apoptosis of lymphocytes. Human peripheral blood lymphocytes Peng-EBV were exposed to ¹²C ions beams at different doses (0 Gy, 0.5 Gy, 2.0 Gy) at the dose rate of 0.3-0.5 Gy/min. Cell apoptosis was detected by using flow cytometry (FCM) at 12, 24, 48 hours, 20, 30 day post irradiation. Apoptosis occurred at 12 hour post irradiation, and at 24 hour the rate of apoptosis was the highest, an obvious drop appeared at 48 hour post irradiation, a recovery from ¹²C ion-induced apoptosis at 30 day post irradiation. The mumber of apoptotic and necrotic in Human peripheral blood lymphocytes at 12, 24, 48 hour post irradiation signilificantly increased compared with the control; Apoptosis irradiated by 2.0 Gy of ¹²C ions was slightly larger than the 0.5 Gy, and has a long time. These results suggest that¹²Cion beam exposure can induce lymphocytes apoptosis and necrosis, and it is related to the dose and time.

Key words: Apoptosis, Heavy ions, Human peripheral blood lymphocytes