Co-oxidation of luminol by hypochlorite and hydrogen peroxide implications for neutrophil chemiluminescence

Abstract

Stimulated neutrophils produce several potent oxidants including H 2O 2, O 2 − and HOCl. Previous studies have revealed all of these compounds to be capable of oxidizing luminol, a reagent often used to indicate, by its chemiluminescence, the oxidative burst of neutrophils. Data presented in this paper indicate that H 2O 2 and HOCl spontaneously react at physiologic pH to produce luminol-dependent chemiluminescence 100 times the sum of the chemi luminescence of either reagent alone. This enhancement is due to a cooxidation by HOCl and H 2O 2, or to a novel oxidant generated by the interaction of HOCl and H 2O 2. The HOCl scavenger, taurine, inhibits the chemi luminescence. Evidence is presented against the participation of hydroxyl radical, O 2 − or singlet oxygen in the oxidation of luminol by HOCl and H 2O 2. These findings have implications for potential anti-inflamatory compounds.