Reactive Oxygen Release

Monocytes, macrophages, neutrophils, and eosinophils are able to generate and release reactive oxygen species. The reactive oxygen species are generated by reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase which is activated by a number of different soluble and particulate agents. This activation results in the reduction of molecular oxygen to the potentially toxic oxygen species superoxide anion (O₂ ⁻ ), or hydrogen peroxide (H₂ O₂ ), with NADPH serving as the electron donor. In the presence of eosinophil peroxidase, H₂ O₂ may then give rise to the potentially cytotoxic hypohalous acids such as HOBr. The increase in oxygen consumption is termed the respiratory burst (1 ,2 ).