Evidence for hydroxyl radical production by human neutrophils

Abstract

The possibility that neutrophils produce the hydroxyl radical (OH.) was studied by examining the ability of these cells to support the release of ethylene from methional, a reaction in which it has been shown that OH., but not O2- or H2O2, may serve as the oxidizing agent. When neutrophils were exposed to opsonized zymosan in the presence of 0.35 mM methional, ethylene was released in quantities amounting to 44.6 ± 3.6 pmol/106 cells/40 min. Ethylene production required the presence of neutrophils, opsonized zymosan, and methional, indicating that it was formed from methional by stimulated but not resting neutrophils. Ethylene was not produced by zymosan-treated cells from patients with chronic granulomatous disease, confirming the requirement for respiratory burst activity in this process. Ethylene production was suppressed by benzoic acid, an OH. scavenger. Superoxide dismutase (3 μg/ml) reduced ethylene production to 21% of control levels, but catalase had no significant effect in this system. These findings indicate that stimulated neutrophils produce a highly reactive oxidizing radical, possibly OH., which releases ethylene from methional, and that the O2- generated during the respiratory burst is involved in the production of this reactive species.