Interactions of some acceptors with superoxide anion radicals formed by the NADPH-specific flavoprotein in rat liver microsomal fractions

Abstract

In rat liver microsomal fractions oxidation of adrenaline was effected by superoxide anion radicals (O₂^-), whereas cytochrome c, 2,6-dichlorophenol-indophenol and ferricyanide accepted electrons from NADPH-specific flavoprotein only directly. Nitro Blue Tetrazolium was reduced both by O₂^- and by the direct acceptance of electrons. Elevation of pH and addition of menadione shift the Nitro Blue Tetrazolium reduction towards the O2^--dependent pathway. From the values of the kinetic constants for interaction of adrenaline and Nitro Blue Tetrazolium with NADPH-specific flavoprotein, the rates of generation of O₂^- in rat liver microsomal fraction were determined.