Calculated cell-specific intracellular hydrogen peroxide concentration: Relevance in cancer cell susceptibility during ascorbate therapy.

The high extracellular hydrogen peroxide (HO) concentrations generated during pharmacological ascorbate (P-AscH) therapy has been shown to exhibit a high flux into susceptible cancer cells leading to a decrease in clonogenic survival. It is hypothesized that the intracellular HO concentration for susceptibility is independent of cell type and that the variation observed in dosing is associated with differences in the cell-specific overall steady-state intracellular HO concentration values. The steady-state variation in intracellular HO concentration is coupled to a number of cellular specific transport and reaction factors including catalase activity and membrane permeability.