Mechanism Of Free Radical In The Stimulating Effect Of Cell Proliferation Caused By Low Level Radiation And In The Proliferation Of Peripheral Blood Lymphocyes Cultured With Monocytes

Objective: To study the role of superoxide anions in the proliferation effects of mice bone marrow cells caused by low level radiation and the proliferation effects of peripheral blood lymphocytes cultured with monocytes .Methods: Mice bone marrow cells were respectively radiated by different doses (0 2 4 6 8 10cGy) of y -rays. After radiation, the ability of cell proliferation was determined by 3H-TdR incorboration method, the concentration of superoxide anions was measured by cyt.c reduction method. PMA and DPI were respectively added into culture medium to increase or decrease the concentration of superoxide anions, and the change of cell proliferation was observed. Lymphocytes and monocytes were isolated from human peripheral blood , then the lymphocytes were cultured with different amounts of monocytes , the ability of lymphocytes proliferation and the concentration of O2were measured by above methods. We added DPI into culture medium to depress the activity of NADPH oxidase , which produces superoxide anions, to observe the change of the cell proliferation.Results : In a certain concentratin range , the proliferation ability of mice bone marrow cells increase with the increasement of superoxide anions . The optimum concentration of superoxide anions , which resulted in the maximal proliferative effect of mice bone marrow cells, was 1.8-1.9nmol/h/106cells. Superoxide anions also can causelymphocytes proliferation and it increases with the increasement of monocytes.Conclusion: Superoxide anions play an important role in the proliferative effect caused by low level radiation and in the proliferation of peripheral blood lymphocytes cultured with monocytes .