Continuous Monitoring of Superoxide Production by Phagocytes

Resting phagocytes — granulocytes (PMN), monocytes, and most macrophages primarily metabolize anaerobically, consume only small amounts of oxygen, and produce little if any O₂ ⁻ and H₂O₂. Upon interaction with certain soluble or particulate stimuli, however, there is a change in the metabolic activity of these cells. After a lag period, these cells will begin to consume oxygen, produce O₂ ⁻ and H₂O₂, and increase their hexose monophosphate shunt activity. ¹ Depending on the type of stimulus, the lag period ranges from a few seconds to a few minutes and the duration of this change in metabolism may last from 1 to approximately 30 min.