Assay for Oxidative Metabolism

Phagocytic leukocytes that are exposed to opsonized particles, chemoattractants, or selected cytokines undergo a rapid burst in oxygen consumption and activation of the enzyme responsible for the oxidative metabolic burst, NADPH oxidase (reviewed in 1 ). Active NADPH oxidase catalyzes the reaction: The O ₂ ^- formed by NADPH oxidase activity can rapidly be converted into H ₂ O ₂ and other toxic species that destroy microorganisms and impart injury to surrounding host tissue. The most direct evidence for the role of NADPH oxidase in host defense has come from studies of patients who have genetic defects in NADPH oxidase activity (chronic granulomatous disease). Chronic granulomatous disease patients suffer from recurrent, severe bacterial infections, which are often fatal in early childhood.