The Generation of Superoxide Radical during the Autoxidation of Hemoglobin

The autoxidation of oxyhemoglobin to methemoglobin, at pH 6.8, causes the co-oxidation of epinephrine to adrenochrome. Part of this co-oxidation was due to a hemoglobincatalyzed peroxidation of epinephrine and could be inhibited by catalase. The remainder of the co-oxidation of epinephrine was inhibited by superoxide dismutase. This indicates that the autoxidation of oxyhemoglobin results in the generation of superoxide radicals.