Role of Reactive Oxygen Specie in Arthus Reaction

Abstract

SummaryThe effect of serum obtained from Arthus reaction-elicited rabbits on the generation of reactive oxygen species (ROS) by normal rabbits' polymorphonuclear leukocytes (PMNs) was examined.. The oxidative metabolism of infiltrating PMNs in the skin during the Arthus reaction was observed by the nitroblue tetrazolium dye reduction test (NBT test). The significantly increased H2O2 generation by normal PMNs was observed when PMNs were incubated with serum obtained 24 and 48 h after the elicitation. Also the increased O2 -generation was noted after incubation with serum taken at 48 h after the elicitation. Many NBT-positive PMNs were observed in skin specimens obtained 24 and 48 h after the elicitation. These results may indicate the importance of ROS generated by infiltrating PMNs in immune complex vasculitis because the Arthus reaction is a model of immune complex vasculitis.Key Words: Arthus reaction, immune complex vasculitis, reactive oxygen species, skin NBT test The experimental Arthus reaction, which is a model of immune complex vasculitis, is similar to necrotizing vasculitis both macroscopically and histologically. In its pathogenesis, immune complexes (ICs) deposited on the wall of blood vessels activate the complement system with resultant production of chemotactic factors such as Coa. Then, attracted polymorphonuclear leukocytes (PMNs) produce various inflammatory mediators, and induce tissue damage in the wall of the blood vessels. These reactions are observed macroscopically as redness, induration, and bleeding, and histologically as dense infiltration of PMNs, fibrinoid degeneration of blood vessels, and nuclear dusts. In rabbits, the Arthus reaction was suppressed both macroscopically and histologically when colchicine was injected intraperitoneally before elicitation [1], indicating that PMNs play an im-*To whom correspondence should be addressed .