ABSTRACT
Objective To separate NK cells of mice from NK cell separation medium and study inhibitory effect of proliferated NK cell induced by low dose radiation on the leukemia model of K562 cells.Methods Flow cytometry and 3H-TdR methods were respectively used to measure proliferation index and activity of NK cells treated with low-dose radiation( which means exposure dose in 20 cGy low LET beam or 5 cGy high LET beam).CD13 + cells were measured by flow cytometry and TNF-α content in blood-serum was detected by ELISA.In vivo,peripheral blood leucocyte count,index of liver,indexes of spleen and kidney were observed in control group and experimental group.Results The purity of NK cell separation was (82.54 ± 0.18)%.The proliferation index of NK cells at 24 hours after 80 mGy irradiated was 36.31 ± 1.32% ,(t =24.69,P ＜0.05).Killing activity of NK cell induced by low dose radiation to K562 cell was (12.59±0.63)%(t=6.63,P＜0.05)and the inhibition ratio was 29.52%.Conclusion The injection of proliferated NK cell induced by low dose radiation demonstrated significant inhibitory effect on the growth of leukemia nude mouse.