Comparative Effects of Neutrons and X-Rays on Mammalian Cells

Fast neutrons and 280-Kvp x-rays were used to irradiate four types of mammalian cell. The effects studied were the loss of proliferative capacity, the inhibition of mitosis, and the production of mitotic abnormalities. A concept of relative biological efficiency was defined and used to compare these three effects. The results agree with the view that the mechanism which produces the loss of proliferative capacity is chromosomal in nature. They also suggest that the radiation damage which causes mitotic inhibition may not be the same as the damage which leads to the loss of the ability of a cell to proliferate indefinitely. Preliminary results indicate that the recovery phenomenon present after x irradiation is not present after neutron irradiation.