In vitro and in vivo detection of irradiation-induced free radicals

Abstract

Purpose/Objective: Detection of free radicals generated in vitro and in vivo with spin trap reagents has been very difficult, due to the interaction of free readicals with other proteins or metabolism of spin trap adducts by cells. Irradiation of cells results in the production of free radicals which results in DNA strand breaks, lipid peroxidation, or protein deactivation. We have previously demonstrated that overexpression of manganese superoxide dismutase (MnSOD) protects cells both in vitro and in vivo from irradiation. One mechanism by which MnSOD may protect cells is due to reduction of superoxides during irradiation. In order to determine whether this mechanism is possible we need to measure free radicals produced following irradiation. We have used the spin trap reagent POBN and generation of an ascorbate radical as a method to detect free radicals produced following irradiation to see if overexpression of MnSOD may mediate the reduction of free radicals produced following irradiation.