The role of reactive oxygen metabolites in murine peritoneal
macrophage phagocytosis and phagocytic killing.
Takao, Sonshin, Elise H. Smith, Dajie Wang, Candy K. Chan, Gregory B.
Bulkley, Andrew S. Klein.
Department of Surgery, Division of Liver Transplantation, The Johns
Hopkins University School of Medicine, 600 N. Wolfe St., Baltimore,
Md. 21287
APStracts 3:0127C, 1996.
This study was designed to quantify the role of reactive oxygen
metabolites (ROMs) in two distinct components of murine peritoneal
macrophage activity - phagocytosis and killing - and to discriminate
quantitatively the degree to which each component is dependent upon
NADPH oxidase and/or xanthine oxidase. A fluochromatic vital staining
technique was modified to simultaneously quantify phagocytosis, and
microbicidal activity of macrophages incubated with Candida
parapsilosis targets. To determine the role of ROMs, macrophages were
preincubated with free radical scavengers (superoxide dismutase, SOD
and/or catalase), or with selective inhibitors of XO (allopurinol) or
NADPH oxidase (diphenyleneiodonium, DPI). Phagocytosis was not
affected by treatment of macrophages with SOD, catalase, allopurinol,
or DPI. Candidacidal activity, however, was inhibited by SOD,
allopurinol, or DPI. The inhibitory effects of DPI and allopurinol
were additive. Histochemical and biochemical assays demonstrated
substantial quantities of XO in murine peritoneal macrophages. The
findings suggest that the generation of ROMs by both XO and NADPH
oxidase-dependent pathways are each important for phagocytic killing
by murine peritoneal macrophages.
Received 17 May 1995; accepted in final form 28 March 1996.
APS Manuscript Number C285-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 1 May 96