Generation of Nitrogen-Chlorine

Human phagocytes can be triggered to generate large quantities of long-lived nitrogen-chlorine derivatives. This class of oxidants can be detected as early as 5 min after the addition of phorbol myristate acetate or opsonized zymosan particles. Unlike all other oxygen metabolites known to be generated by phagocytes, the nitrogen-chlorine compounds can be readily detected in cell supernatants 90 min after stimulation. The generation of these oxidants is linear with neutrophil concentration, favored at alkaline pH, and inhibited by supraphysiologic concentrations of iodide or bromide. The oxidants are hydrophilic in nature and have a halflife ranging from 5 h at 370C to >100 h at 40C. Gel filtration chromatography of the accumulated nitrogenchlorine derivatives revealed that the oxidants generated by neutrophils or monocytes are a complex mixture of products whose Mr range from 150-5,000. One-half of the nitrogen chlorine derivatives migrate as a single peak with an Mr of 150. Amino acid analysis of this fraction identified the I-amino acid, taurine, as the single nitrogenous compound present. Neutrophils triggered in the presence of serum albumin accumulated increased amounts of the nitrogen-chlorine derivatives while continuing to generate their endogenous low M, oxidants. Quantitative analysis of the 36C1 incorporation revealed that the albumin molecule was chlorinated with the formation ofboth nitrogen-chlorine and carbon-chlorine This work was presented in part at the annual meeting of the American Society of Hematology, San Francisco, California, 6 December 1983. Address reprint requests to Dr. Weiss, Simpson Memorial Research Institute, 102 Observatory, Ann Arbor, MI 48109-0010. Receivedfor publication 17 April 1984 and in revisedform 26 June 1984. bonds. We conclude that human phagocytes can chlorinate both endogenous and exogenous nitrogenous compounds at inflammatory sites to generate a heterogeneous mixture of nitrogen-chlorine derivatives. The ability of phagocytes to generate this class of long-lived oxidants whose hydrophilic characteristics restrict their localization to the extracellular space suggests that these species play an important role in modulating the inflammatory response.