Alternative Pathways of Sulfite Oxidation in Human Polymorphonuclear Leukocytes

Sodium sulfite is metabolized by human polymorphonuclear leukocytes by two alternative pathways, one enzymatic route dependent on sulfite oxidase and one non-enzymatic which involves intermediate formation of sulfur trioxide anion radicals. Initiation of the oxidative burst by phorbol myristate acetate significantly stimulates sulfate formation through the second pathway. The activity of sulfite oxidase in polymorphonuclear leukocytes varies greatly among individuals, a variation consistent with the suggested polymorphic distribution of sulfite oxidase in the human population.