Vitamin C and radioprotection

Gregory raises the question of the mechanism through which vitamin C exerts the radioprotective effect observed by us in Chinese hamster ovary cells (O'Connor et al., 1977). The data we presented was such that in its own right it gave no indication of a likely mechanism. Consequently the basis for the effect was considered equally likely to be physiological or chemical. A chemical mechanism was intended to imply a direct interaction between ascorbate and some radiation induced factors in the cell. On the other hand a physiological mechanism was intended to convey a more complex process whereby the cell was altered by the presence of ascorbate in such a way that it was subsequently more resistant when challenged with radiation.