The respiratory burst of phagocytes.

The Respiratory Burst of Phagocytes hen exposed to certain stimuli, phagocytes (neu- trophils, eosinophils, and mononuclear phagocytes) undergo marked changes in the way they handle oxygen (1). Their rates of oxygen uptake increase greatly, sometimes more than 50- fold; they begin to produce large amounts of superoxide (O-) and hydrogen peroxide (H202); and they start metabolizing large quantities ofglucose by way ofthe hexose monophosphate shunt. Because of the sharp increase in oxygen uptake, this series of changes has come to be known as the "respiratory burst." The "respiration" associated with this burst, however, has nothing to do with energy production; rather, its purpose is to generate powerful microbicidal agents by the partial reduction ofoxygen.