Superoxide anion generation by human neutrophils exposed to monosodium urate. effect of protein adsorption and complement activation

Authors

  • Steven Abramson MD,

    Corresponding author
    1. Department of Medicine, Division of Rheumatology, New York University School of Medicine, New York, NY 10016.
    • New York University Medical Center, 550 First Avenue, New York, NY 10016
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  • Sylvia T. Hoffstein,

    1. Department of Medicine, Division of Rheumatology, New York University School of Medicine, New York, NY 10016.
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  • Gerald Weissmann

    1. Department of Medicine, Division of Rheumatology, New York University School of Medicine, New York, NY 10016.
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Abstract

We studied the capacities of naked and proteincoated monosodium urate (MSU) crystals to stimulate superoxide anion (O2equation image) release by human polymorphonuclear leukocytes (PMN). Uncoated MSU stimulated significant O2equation image production by cytochalasin B-treated PMN. Precoating MSU with IgG caused an increase in mean O2equation image production, whereas precoating heated MSU with serum or plasma inhibited O2equation image release. Unheated MSU crystals, which activate complement to a greater extent than heated crystals, also provoked O2equation image generation, an effect again abrogated by precoating with serum but not with plasma. Coincubation of unheated MSU and plasma resulted in an enhancement of O2equation image generation. The results of these experiments support the hypothesis that adsorbed proteins modulate the phlogistic potential of MSU and that the surface activation of humoral mediators contributes to the local inflammatory response.

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